Journal of Composites Science doi: 10.3390/jcs10060323

Authors: Ioannis Filippos Kyriakidis Savvas Koltsakidis Michel Theodor Mansour Apostolos Korlos Constantine David Konstantinos Tsongas Dimitrios Tzetzis

In this study, the development of a novel machine mount utilizing an advanced polymer composite and porous materials is presented. Initially, a preliminary evaluation of the proposed materials was conducted, focusing on their static mechanical properties and their dynamic properties, and assessed through loading–unloading cycles and Dynamic Mechanical Thermal Analysis (DMTA). All tests were performed at the coupon scale, with specimens manufactured via Fused Filament Fabrication (FFF). Subsequently, a conceptual design incorporating the proposed materials was developed, and functional prototypes were fabricated using multi-material additive manufacturing techniques. The structural integrity of the prototypes was evaluated by analyzing their oscillatory response and damping behavior under laboratory-scale conditions, with transmissibility metrics extracted to quantify performance. The results indicate that all three prototypes exhibit adequate damping for machine mounting applications, ranging between 5% and 20%, with the porous variant demonstrating the highest damping performance (20.9%). In terms of load-bearing capacity, the porous configuration withstood loads up to 10 kN, while the standard TPU variant sustained up to 20 kN. The carbon-fiber-reinforced configuration exhibited the highest mechanical performance, tolerating loads up to 50 kN without significant structural failure.

Journal of Composites Science doi: 10.3390/jcs10060322

Authors: Ana Martins Amaro Maria Augusta Neto

Glass fiber reinforced epoxy laminates (GFRP) are increasingly used in structural applications where combined mechanical and environmental loading is unavoidable, such as in the aerospace, naval, automotive, and petrochemical industries. This study investigates the influence of aggressive environments on the impact response and damage mechanisms of GFRP laminates. Specimens were immersed in acidic (hydrochloric and sulphuric) and alkaline solutions (sodium hydroxide), oil (automotive engine and automotive brake fluid), and cementitious solutions (cement and metakaolin mortars) for a determined period to simulate severe service conditions. Low-velocity impact tests were subsequently performed to evaluate the residual impact performance in terms of absorbed energy, maximum force, and damage extent. The results demonstrate that environmental exposure significantly alters impact behavior, mainly through matrix plasticization, fiber-matrix interface degradation, and microcrack development. For shorter immersion times (12–30 days), the solutions are not highly aggressive, as the decrease in elastic energy remains below 15%, with cementitious solutions showing the lowest reductions even for longer exposure periods. In contrast, longer immersion times in alkaline solution, DOT4 oil, and metakaolin mortar lead to more severe deterioration, with elastic energy reductions between 30% and 40%, the most aggressive condition being immersion in NaOH for 36 days, which caused a 37.4% decrease. Alkaline and automotive brake fluid oil environments induced the most severe degradation, leading to reduced impact resistance and increased damage propagation.

Journal of Composites Science doi: 10.3390/jcs10060321

Authors: Jianwen Hao Qinsheng Xu Zhenlei Lv Zhaocheng Rui Zhansheng Ding Enzhou Di

This study aims to solve the problems of the high carbon emissions, poor compatibility, and insufficient storage stability of conventional polymer–modified bitumen (PMB). A novel High–Modulus Polyurethane Prepolymer (HM–PU) bitumen modifier was independently prepared to explore its modification effect and optimal application parameters. Experimental results show that the optimal isocyanate group (NCO) content and dosage of the HM–PU modifier are both 5%. The thermal stability and high– and low–temperature performance of modified bitumen are significantly enhanced, and HM–PU exhibits excellent compatibility with base bitumen (BA). This work innovatively synthesizes the HM–PU modifier and clarifies its physicochemical modification mechanism via macroscopic performance tests, thermal analysis, and microscopic characterization, providing a new strategy for the development and application of eco–friendly bitumen modifiers.

Journal of Composites Science doi: 10.3390/jcs10060320

Authors: Ganiyat Salawu Glen Bright

The development of lightweight aluminum matrix composites with improved mechanical performance and thermal stability using sustainable reinforcement materials remains a significant challenge in structural materials engineering. Although ceramic-reinforced aluminum composites exhibit enhanced strength and thermal resistance, the potential of bio-derived snail shell particles as environmentally sustainable reinforcements remains insufficiently explored. In this study, snail-shell-reinforced AA6061 aluminum matrix composites were fabricated by stir casting to investigate their microstructural characteristics, mechanical behavior, phase composition, and thermal stability. Snail shell particles, predominantly composed of CaCO3, were processed to particle sizes of 50–75 µm before incorporation into the molten aluminum matrix. Characterization was performed using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), tensile and hardness testing, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results revealed relatively uniform particle dispersion and satisfactory matrix–reinforcement interfacial compatibility. The tensile strength increased from 155 ± 5 MPa for the unreinforced alloy to 211 ± 4.8 MPa for the reinforced composite, corresponding to an improvement of approximately 36%, while elongation increased from 2.4 ± 0.2% to 4.6 ± 0.4% (92%). XRD analysis confirmed the presence of Al, CaCO3, Mg2Si, and minor CaO phases, indicating successful reinforcement incorporation and strengthening phase formation. Thermal analysis demonstrated enhanced thermal stability, increased residual mass retention, and improved resistance to thermal degradation. This work demonstrates that bio-derived snail shell particles are viable and environmentally sustainable reinforcements for lightweight aluminum matrix composites intended for structural engineering applications.

Journal of Composites Science doi: 10.3390/jcs10060319

Authors: Dingfeng Zhang Enzhou Di Yongfeng Zhao Xiangpeng Yan Zhiwen Wang Zhaocheng Rui

Ambient-temperature asphalt binders have emerged as a sustainable alternative to traditional hot-mix asphalt, offering significant advantages in energy conservation and emission reduction. This review systematically examines the research progress and development trends of high-performance reactive asphalt binders designed for ambient-temperature application, which achieve enhanced performance through chemical cross-linking reactions. The study focuses on three core material systems: epoxy resin, waterborne epoxy emulsified asphalt, and polyurethane. For each system, we comprehensively summarize the material composition, strength formation mechanisms, and mix design methodologies. Key evaluation methods for critical pavement performance—including strength characteristics, water stability, and high-temperature performance—are critically reviewed. Furthermore, microscopic characterization techniques including scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) are discussed to elucidate the underlying mechanisms governing performance evolution. Analysis reveals that epoxy-based binders exhibit superior strength and stiffness, rendering them suitable for heavy-traffic pavements; waterborne epoxy emulsified asphalt binders combine environmental compatibility with construction convenience for thin-layer rehabilitation, while polyurethane-based binders demonstrate exceptional elasticity and rapid curing characteristics for quick-traffic-opening scenarios. Although current research has established a preliminary performance evaluation framework, the absence of unified technical standards constrains widespread engineering implementation. Future research priorities should focus on developing water-triggered curing systems, intelligent responsive materials, and comprehensive standardization systems to fully harness the engineering potential of these sustainable binders.

Journal of Composites Science doi: 10.3390/jcs10060318

Authors: Mostafa Meraj Pasha Md Shakil Arman Zhijian Pei Stephen Kachur

Silicon carbide–aluminum (SiC–Al) composites offer high hardness, wear resistance, thermal stability, and strength-to-weight ratio, making them suitable for advanced engineering applications. Fabricating these composites via powder metallurgy and infiltration methods has been reported. However, there is no reported study on fabricating SiC–Al composites using binder jetting additive manufacturing (BJAM) followed by sintering without infiltration. The present study aims to fill this gap. In this study, samples were printed by BJAM using SiC–Al mixed powders with two volumetric ratios (SiC:Al) of 60:40 and 80:20, respectively. These printed samples were then sintered at different temperatures (950 °C, 1200 °C, and 1400 °C). The results show that, using this new approach, the printed green samples retained structural integrity after sintering and that interparticle bonding was achieved. To the authors’ knowledge, this is the first study to fabricate a SiC–Al composite via binder jetting additive manufacturing using a mixed powder, followed by sintering without infiltration.

Journal of Composites Science doi: 10.3390/jcs10060317

Authors: Tej Singh Vedant Singh Sharafat Ali Meizi Wang Gusztáv Fekete

This study investigates the effect of waste cement dust (CD) and rock wool (RW) inorganic fiber on the tribological performance of brake friction composite materials. Five formulations were fabricated by varying CD from 65 to 45 wt.% and RW from 5 to 25 wt.% and evaluated for tribological properties on a Chase friction testing machine in accordance with IS 2742 test procedures. The results show that composites containing higher CD and lower RW exhibited higher coefficients of friction, lower friction variability, and improved fade resistance. In contrast, composites containing higher RW and lower CD showed improved recovery characteristics and substantially enhanced wear resistance. The performance coefficient of friction decreased from about 0.521 to 0.442 as the formulation shifted from CD-rich to RW-rich compositions, while the variability coefficient increased from about 0.364 to 0.516. The highest wear was recorded for the composite containing 65 wt.% CD and 5 wt.% RW inorganic fiber, whereas the lowest friction fluctuations were obtained for the composite containing 55 wt.% CD and 15 wt.% RW inorganic fiber. Finally, a simple ranking process-based decision-making technique was employed to evaluate the overall performance of all the composites, suggesting 55 wt.% CD as the optimal content. These findings confirm the potential of waste CD as a viable functional constituent in brake friction composites when combined with RW inorganic fiber in an optimized manner.

Journal of Composites Science doi: 10.3390/jcs10060316

Authors: Asrial Ketut M. Kuswara Gauris Panji Er Lambang Roly Edyan Paul G. Tamelan Alesandra Sania Itu

Infrastructure expansion in Indonesia has increased demand for paving blocks, raising concerns over cement production costs and environmental impact. This study investigates the comparative effectiveness of pineapple leaf fiber (PALF, Ananas comosus) and sisal fiber (Agave sisalana) as reinforcements in paving blocks, evaluating water absorption and 28-day compressive strength at fiber contents of 0%, 1%, 3%, 5%, and 7% by cement volume. A full-factorial two-way ANOVA with post-hoc Tukey HSD was employed. A dosage of 3% for both fiber types resulted in compressive strengths of 14.5 MPa (PALF, +59% vs. control) and 15.2 MPa (sisal, +67% vs. control), both of which met the requirements of SNI 03-0691-1996 Class B. Sisal fiber demonstrated superior compressive performance, consistent with its higher stiffness and tensile strength as reported in the literature. Water absorption increased monotonically with fiber content for both types, with SNI Class D compliance (≤10%) maintained only at 0% for PALF and 0–1% for sisal, a known consequence of the inherently hydrophilic nature of plant-based natural fibers. A statistically significant interaction term (F = 3.697, p = 0.012) confirmed that the two fibers respond differently to dosage increases, providing nuanced practical guidance beyond what single-factor studies can offer. These findings demonstrate the promising compressive strength of agricultural waste fiber-reinforced paving blocks, warranting further investigation of abrasion resistance, flexural strength, and long-term durability before practical deployment. Such utilization supports circular economy principles in the construction industry.

Journal of Composites Science doi: 10.3390/jcs10060315

Authors: Katherine Liset Ortiz Paternina Rodrigo Ortega-Toro Joaquín Hernández Fernández

This study analyzed the initial adsorption and activation of CO2 on bimetallic CunSc nanoclusters, with n = 3–7, using DFT calculations in ORCA with the r2SCAN-3c method. A total of 20 bare clusters and their corresponding CunSc–CO2 complexes were investigated, considering four structural configurations for each composition. To avoid classification based solely on adsorption energy, a global CO2 activation index was developed and defined as IACO2 = z(AG) + z(CTCO2) + z(Bending) + z(ΔrC–O). In this index, AG = −ΔGads, CTCO2 = −qCO2, bending corresponds to (180° − ∠O–C–O), and (ΔrC–O) represents the average elongation of the C–O bonds. This descriptor enabled distinguishing complexes that only stabilize CO2 from those that induce effective geometric and electronic activation. Although 5IV and 3IV exhibited favorable adsorption, with (ΔGads) values of −52.978 and −53.494 kcal mol−1, respectively, their molecular activation was low, with nearly linear CO2 and minimal or unfavorable charge transfer. In contrast, 7III and 7II showed the highest activation, with CTCO2 values of 1.206 and 1.163, bending values of 69.867° and 68.869°, and C–O elongations of 0.208 and 0.195 Å, respectively. The standardized (IACO2) ranking identified 7III, 7II, 3III, and 3II as the most relevant systems, with scores of 100.0, 93.8, 88.2, and 86.8, respectively. These results show that CO2 activation on CunSc nanoclusters should not be assessed solely by (ΔGads), but rather by a multi-criteria approach that accounts for stability, charge transfer, and molecular distortion.

Journal of Composites Science doi: 10.3390/jcs10060313

Authors: Gen Liu Dongxiao Li Boliang Liu Ruiyang Sun Xin Jiang Hao Lv Wensai Ma

Graphene-reinforced aluminum-based materials perfectly combine the excellent properties of graphene and aluminum, achieving superior lightweight structural characteristics. This study focuses on 1:2 internal resonance, analyzing the amplitude–frequency and force–amplitude responses of a graphene-platelet-reinforced aluminum-based truncated conical shell under multiple external excitations. Considering three different graphene distributions, an improved Halpin–Tsai mechanical model is used to predict the effective Young’s modulus of the GPL-enhanced aluminum-based truncated conical shell. Under temperature effects, based on the Reissner–Mindlin theory and von-Karman geometric nonlinear strain–displacement relationships, Hamilton’s principle and the Galerkin method are employed to derive the motion equations of the GPL-enhanced aluminum-based truncated conical shell. Through multiscale perturbation analysis, the averaged equations in polar coordinates are further derived. Based on the combined averaged equations, the amplitude–frequency and force–amplitude response curves of the system are plotted, investigating the influence of graphene distribution, graphene content, external excitation amplitude, tuning parameters, and graphene plate geometrical dimensions on its vibration characteristics. The analysis results indicate that graphene content is one of the primary factors affecting the vibration characteristics of graphene-reinforced aluminum-based truncated cones.

Journal of Composites Science doi: 10.3390/jcs10060314

Authors: Christos Tsonos

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Journal of Composites Science doi: 10.3390/jcs10060311

Authors: Komeil Farshidi Abbas Akbarpour Asghar Habibnejad Korayem Morteza Ebrahimi

Cementitious materials are naturally brittle, which makes them prone to cracking. This study effectively employs autogenous healing techniques using microcapsules to solve this issue. The goals were twofold: first, to microencapsulate isophorone diisocyanate (IPDI) as a catalyst-free healing agent; and second, to evaluate how these microcapsules improve the healing abilities of cementitious materials. Polyurethane (PU) prepolymer with an NCO content of 19.8% was successfully created. Using interfacial polymerization, smooth, spherical microcapsules of IPDI with an average diameter of 38 to 62 micrometers were produced. The elastic modulus of the microcapsules ranged from 0.23 to 0.18 GPa, while their hardness varied between 5.29 and 4.15 MPa. Over six months, the microcapsules showed a weight loss of 9.72% to 12.47%, depending on their size, under ambient conditions. Specimens containing 3% of fabricated microcapsules demonstrated the ability to seal cracks less than 100 µm wide by up to 70%. Specimens that incorporated 3% of their cement weight in IPDI microcapsules achieved an impressive 74% recovery rate in compressive strength. In contrast, control mortars without microcapsules showed a recovery rate of less than 50%. Analysis using Energy Dispersive Spectroscopy (EDS) revealed a significant presence of carbon in areas where the microcapsules had ruptured and the cracks had healed. This confirms the effectiveness of the healing process, consistent with established self-healing theories. The water tightness recovery trace showed a recovery rate of up to 61%. Additionally, the specimens containing microcapsules exhibited higher initial compressive strength than the control specimens. However, this also indicates that some microcapsules may have ruptured unintentionally during preparation and molding. Therefore, further research on the mechanical properties of microcapsules, especially their stiffness in cementitious composites, is necessary.

Journal of Composites Science doi: 10.3390/jcs10060312

Authors: Kinam Hong Sangwon Ji Kyubyung Kang Bhumkeun Song

Pultrusion is an efficient continuous manufacturing process for fiber-reinforced polymer (FRP) composites, but conventional open-bath impregnation has limitations such as resin exposure, quality variation, and resin loss. To overcome these limitations, closed-injection pultrusion (CIP) and short-pot-life resin systems have recently been introduced. However, the effects of processing variables on the quality and properties of composites manufactured using such resin systems have not been fully clarified. In this study, the effects of resin viscosity and pulling speed on the quality and mechanical properties of carbon FRP (CFRP) and glass FRP (GFRP) composites manufactured by CIP were investigated. CFRP and GFRP composites were fabricated at resin temperatures of 30 and 40 °C and pulling speeds of 300, 400, and 500 mm/min. The manufactured composites were evaluated in terms of void content, microstructure, hardness, and tensile properties. The results showed that increasing pulling speed increased void content and promoted macrovoids and locally poor impregnation, whereas the influence of resin temperature was relatively limited. Hardness, tensile strength, and elastic modulus decreased as pulling speed increased. These results demonstrate that CFRP and GFRP composites can be successfully manufactured by CIP using short-pot-life resin systems, and that precise control of resin viscosity and pulling speed is essential for achieving high quality and mechanical performance.

Journal of Composites Science doi: 10.3390/jcs10060310

Authors: Fatima Shamal Atiyah Amjad H. Albayati

Moisture-induced damage is one of the primary causes of premature distress in asphalt pavements, leading to reduced service life and increased maintenance costs. Although nanomaterials have shown potential in enhancing asphalt performance, the underlying composite interaction mechanisms among nanomaterials, asphalt binder, and aggregate phases under moisture exposure are still not fully understood. In addition, comparative evaluations under consistent experimental conditions remain limited. This study investigates the influence of five nanomaterials: nano-silica (NS), nano-alumina (NA), nano-titanium dioxide (NT), nano-zinc oxide (NZ), and carbon nanotubes (CNT) on the physical and mechanical properties of asphalt binders and mixtures, with particular emphasis on moisture damage resistance. The nanomaterials were incorporated at dosages of 1.5%, 3.0%, 4.5%, and 6.0% by binder weight. Binder performance was evaluated using conventional and performance grading (PG) tests, while mixture performance was assessed through Marshall properties and moisture susceptibility indicators, including the tensile strength ratio (TSR) and the index of retained strength (IRS). Fluorescence microscopy (FM), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were employed to investigate nanomaterial dispersion characteristics, microstructural morphology, and physicochemical interactions within the asphalt composite system. The results indicate that nanomaterial modification reduced penetration and increased softening point and Marshall stability, reflecting enhanced stiffness and thermal resistance, although ductility decreased at higher dosages. Significant improvements in moisture resistance were observed, particularly under conditioned states. The TSR increased from 81.2% for the control mixture to 92.4% for NS and 91.7% for NA, while the IRS improved from 72.7% to 88.5% for NS. Statistical analysis indicated that both nanomaterial type and dosage significantly affected TSR and IRS performance, with dosage exhibiting comparatively greater influence on moisture resistance improvement. FM and SEM analyses revealed comparatively better dispersion and lower agglomeration tendency for NS and NA, which corresponded to their superior moisture resistance performance. FTIR analysis indicated that the modification process was predominantly physical, with no major formation of new chemical functional groups. Among the investigated nano materials, NS at 6% dosage exhibited the most pronounced improvement, followed by NA at similar dosage levels. Overall, the findings suggest that nanomaterial modification can considerably improve the moisture resistance and mechanical performance of asphalt mixtures under laboratory conditions. However, higher nanomaterial dosages may adversely affect binder workability due to increased viscosity, particularly in CNT-modified binders.

Journal of Composites Science doi: 10.3390/jcs10060309

Authors: Mahmoud T. Nawar Ahmed S. Salem Said Abdel-Monsef Yasser E. Ibrahim Shady Gomaa

Steel–concrete composite beams are widely used in bridge infrastructure but are vulnerable to deterioration due to uniform and pitting corrosion, particularly at the lower flange. This study investigates the flexural behavior of corroded steel–normal strength concrete (NSC) composite beams and evaluates rehabilitation using ultra-high-performance concrete (UHPC) slab replacement, with and without additional steel plate strengthening. A comprehensive finite element analysis was conducted considering three beam spans (5, 7, and 9 m), two corrosion types, and three corrosion levels. The results indicate that both corrosion types significantly reduce flexural capacity due to cross-sectional loss, with pitting corrosion causing greater strength reduction than uniform corrosion at the same weight loss because of stress concentration effects. Replacing the NSC slab with a UHPC slab effectively restores and often enhances load-carrying capacity beyond that of intact beams while reducing dead load, demonstrating the superiority of the proposed rehabilitation approach. The combined use of UHPC slab replacement and welded steel plate strengthening provides the greatest improvement, revealing a strong synergistic effect. A case study of a corroded steel bridge in Pennsylvania confirms the practical applicability of the method, showing that UHPC-based rehabilitation increases the load rating from below unity to above unity. These findings highlight UHPC as an efficient and sustainable solution for extending the service life of aging steel bridges.

Journal of Composites Science doi: 10.3390/jcs10060308

Authors: Hasan Mostafaei Yasaman Anisi Hadi Bahmani Niyousha Fallah Chamasemani Khosro Shabani

High-performance and ultra-high-performance fiber-reinforced concretes (HPFRC/UHPFRC) have emerged as advanced cementitious composites capable of achieving superior mechanical performance, durability, and structural efficiency compared with conventional concrete. However, their widespread adoption remains challenged by relatively high material costs and significant embodied environmental impacts associated with elevated binder and fiber contents. This study presents a comprehensive life-cycle review of advanced high-performance cementitious composites, evaluating their sustainability from raw material extraction and mix design to structural application, service life, and end-of-life considerations. The review synthesizes current knowledge on material composition, production processes, structural performance, durability characteristics, and environmental impacts through the framework of life-cycle assessment (LCA). Particular attention is given to the influence of mix-design parameters, including binder composition, supplementary cementitious materials (SCMs), aggregate systems, and fiber type, on embodied carbon, energy demand, and mechanical performance. A dataset compiled from published experimental studies covering high-performance and ultra-high-performance concrete mixtures is analyzed to examine relationships between compressive strength, embodied energy, and carbon footprint, highlighting the dominant role of cementitious binders and fiber production in environmental impacts. Although advanced fiber-reinforced concretes generally exhibit higher cradle-to-gate emissions than conventional concrete, their superior mechanical properties, improved durability, reduced material demand, and extended service life can substantially reduce life-cycle environmental impacts at the structural level. The review further discusses emerging strategies for developing low-carbon high-performance cementitious composites, including clinker reduction, recycled and alternative fibers, optimized particle packing, and AI-assisted mix design. Finally, key research gaps are identified, particularly regarding standardized LCA methodologies, long-term durability data, harmonized performance-based functional units, and circular-economy strategies for material recycling and reuse. The findings highlight that performance-based life-cycle evaluation is essential for accurately assessing the sustainability potential of advanced high-performance cementitious composites in resilient and low-carbon infrastructure systems.

Journal of Composites Science doi: 10.3390/jcs10060307

Authors: Navid Kharghani Christian Mittelstedt

Thin-walled composite beams with unsymmetric laminates are attracting increasing attention in lightweight aerospace and mechanical structures because they enable enhanced stiffness tailoring and weight reduction beyond the limitations of conventional symmetric stacking sequences. However, despite their practical relevance, unsymmetric thin-walled laminates have received comparatively limited attention in the available buckling literature due to the additional complexity introduced by membrane–bending coupling effects. This study presents an efficient and physically transparent formulation for the buckling analysis of thin-walled composite beams with both symmetric and unsymmetric layups by combining Generalized Beam Theory (GBT) with the Ritz method. The proposed GBT-Ritz framework captures global, local, distortional, torsional, and shear-related deformation modes while consistently incorporating laminate coupling effects associated with unsymmetric configurations. The formulation is applicable to open, closed, branched, and unbranched cross-sections commonly encountered in aerospace structures. Validation against ABAQUS V2017 shell finite element models demonstrates excellent agreement (with discrepancies generally below 6%) in predicting critical buckling loads and mode shapes for various geometries and boundary conditions. The results show that unsymmetric laminates can significantly influence buckling behavior, particularly in open sections and intermediate beam lengths where coupling effects become dominant. Compared with conventional finite element approaches, the proposed method achieves substantially lower computational cost (providing speed-up factors of 1.5 to 2.5) while preserving clear physical insight into interacting instability mechanisms. Overall, the developed framework provides an efficient and practically relevant tool for the analysis and design of advanced thin-walled composite structures with tailored unsymmetric laminates.

Journal of Composites Science doi: 10.3390/jcs10060306

Authors: Ako Abdalrahman Ahmed Bestoon Mohammed Faraj

Adequate polymerization of resin-based composites is essential for marginal sealing and mechanical performance. This study evaluated the effects of different light-curing protocols on gingival microleakage and microhardness of a high-viscosity bulk-fill composite, Filtek™ One Bulk Fill Restorative (3M ESPE; AUDMA, AFM, UDMA, 1,12-dodecane-DMA; silica/zirconia fillers, 76.5 wt%, 58.4 vol%) and conventional nanohybrid composite, Filtek™ Z250 XT Universal Restorative (3M ESPE; Bis-EMA, UDMA; zirconia/silica fillers, 82 wt%, 68 vol%). Forty-eight extracted human second premolars and 48 cylindrical specimens were used for microleakage and Vickers microhardness testing, respectively. Specimens were cured using an O-Star LED unit in turbo mode (2700–3000 mW/cm2, 3 s) or soft-start mode (0–1200 mW/cm2, 20 s) at 2 mm and 5 mm distances. Data were analyzed using Kruskal–Wallis and Dunn’s tests (p < 0.05). Significant differences were found among groups. Soft-start curing at 2 mm produced the lowest microleakage, whereas turbo curing at 5 mm produced the highest. The conventional composite exhibited higher top and bottom microhardness values. Bottom-to-top hardness ratios were below 80% in most groups, except for the conventional composite cured with soft-start mode. Based on our findings, soft-start curing at short distances provides favorable outcomes, while turbo curing at 5 mm is not recommended.

Journal of Composites Science doi: 10.3390/jcs10060305

Authors: Nurzhan Mukhamedov Artur Surayev Nuriya Mukhamedova Aisara Sabyrtayeva Ospan Oken Sergey Dolzhikov Danil Kulbedin

This study investigates the effect of mineral additives of different natures, namely blast-furnace slag, fly ash, and bentonite, on structure formation, phase composition, microstructure, and physicomechanical properties of cement matrices. The analysis included measurements of mass change and linear shrinkage during hardening, determination of density and microhardness, X-ray phase analysis, and microstructural examination by scanning electron microscopy. It was found that the introduction of mineral additives reduced linear shrinkage from 6.06 mm for the control composition to 0.25 mm for the composition with blast-furnace slag, 2.31 mm for the composition with fly ash, and 1.01 mm for the composition with bentonite. The maximum density and microhardness values were obtained for the matrix with blast-furnace slag and amounted to 1.99 ± 0.03 g/cm3 and 39.95 ± 1.12 HV1, respectively, whereas the overall range of values for the investigated compositions was 1.52–1.99 g/cm3 and 30.2–39.95 HV1. X-ray phase analysis showed that the amorphous component varied from 61 to 78%, reaching its maximum value in the composition with blast-furnace slag, which is associated with the formation of poorly crystalline C–S–H and aluminosilicate phases. According to the SEM data, the average size of visible pore-like defects was 2.4 μm for the control composition, 1.4 μm for the composition with blast-furnace slag, 1.3 μm for the composition with fly ash, and 1.7 μm for the composition with bentonite. The most favorable combination of high density, microhardness, developed amorphous component, and homogeneous microstructure was established for the composition with blast-furnace slag. The obtained results can be used as a materials-science basis for the development of cement matrices intended for further studies on the immobilization of solid radioactive waste.

Journal of Composites Science doi: 10.3390/jcs10060304

Authors: Shalahudin Nur Ayyubi Aprilina Purbasari Aji Prasetyaningrum Abdul Wafi Syaiful Ahsan Yustina Yustina Rahmadhani Triastomo Galang Adi Saputra Aulia Rahman Al Fauzan

The growing demand for sustainable materials as alternatives to conventional petroleum-based plastics has accelerated research on alginate-based films. Alginate is a naturally occurring polysaccharide, mainly extracted from brown algae and widely used in the bioindustry due to its biodegradability, film-forming ability, biocompatibility, and functional versatility. However, a comprehensive understanding of global research trends and emerging directions in this field remains limited. This study presents a bibliometric analysis of global research on alginate-based films from 2001 to December 2024, aiming to identify key trends, collaboration patterns, thematic structures, and future directions. The dataset was retrieved from Scopus and analyzed using VOSviewer (v.1.6.20). A significant increase in publications has been observed over the past five years. The International Journal of Biological Macromolecules was identified as the leading journal. “Agricultural and Biological Sciences” dominated the field. China was the most productive country, while Jhong-Whan Rhim was the most prolific author. Jiangnan University was the most active institution. Keyword analysis revealed three themes: mechanical enhancement, food packaging, and biomedical applications. Recent trends indicate a growing focus on sustainable food packaging development.

Journal of Composites Science doi: 10.3390/jcs10060303

Authors: Alina I. Seroshtan Zlata E. Priimak Polina A. Marmaza Dana E. Lembikova Nikita P. Ivanov Vladimir L. Rastorguev Alena R. Zaikova Alexander V. Syuy Yang Chengkai Anton V. Shurygin Vasilii I. Nemtinov Kirill A. Pervakov Ivan G. Tananaev Eugeniy K. Papynov Alexy V. Ognev Oleg O. Shichalin

Lithium-ion batteries require cathode materials with high capacity and cycling stability. Li3V2(PO4)3 (LVP) offers a theoretical capacity of 197 mAh/g but suffers from poor electronic conductivity. In this study, a Li3V2(PO4)3/carbon (LVP/C) composite was synthesized via a citric acid-assisted sol–gel method. The effects of pyrolysis temperature (700–1000 °C) and citric acid-to-salt ratio (1:1, 0.5:1, 0.25:1) were systematically investigated. The optimal composite was obtained at 900 °C with a 1:1 ratio. This material exhibited a well-crystallized monoclinic structure (space group P21/c) with unit cell volume of 890.61 Å3. The amorphous carbon coating provided a specific surface area of 33.03 m2/g. Electrochemically, the optimal LVP/C_1:1 composite delivered an initial specific capacity of 114 mAh/g at C/10 rate—twice that of samples with lower carbon content. It also demonstrated 100% capacity retention after 25 cycles with favorable coulombic efficiency (67%) and reduced charge-transfer resistance. These results show that pyrolysis at 900 °C with a 1:1 citric acid-to-salt ratio provides an optimal balance between crystallinity, carbon coating uniformity, and electrochemical performance for high-performance LVP/C composite cathodes.

Journal of Composites Science doi: 10.3390/jcs10060302

Authors: Ivan Vasilevich Korchunov Sergey Alekseevich Udodov Philip Aleksandrovich Belov Ekaterina Alekseevna Smolskaya Ekaterina Nikolaevna Potapova Aleksandr Alekseevich Susla Olga Eduardovna Shubabko Ksenia Sergeevna Serkina Anna Viktorovna Shkalenko

The study presents an approach to the synthesis of micro- and nano-sized biosilica from rice husk ash (RHA) and describes its effective incorporation into cementitious composites for 3D concrete printing (3DCP). It is demonstrated that the calcination of rice husk at 700 °C, followed by sonochemical treatment, leads to the formation of a nanoscale silica phase with high pozzolanic reactivity. X-ray powder diffraction (XRD), infrared spectroscopy (IR), differential thermogravimetric analysis (DTG), and scanning electron microscopy (SEM) show that the incorporation of nano-biosilica (NBS) into the cementitious composites accelerates the hydration process through a nucleation effect and pozzolanic reaction. This, in turn, densifies the hardened cement microstructure and improves compressive strength significantly. Laboratory 3D concrete printing tests demonstrate that adding 1.72 wt.% NBS improves shape retention, decreases layer slump, and improves interlayer bond strength. The results indicate the viability of rice husk ash-derived biosilica as a supplementary cementitious material (SCM) in 3DCP due to its positive influence on the concrete mortar properties and parameters.

Journal of Composites Science doi: 10.3390/jcs10060301

Authors: Rispandi Nusyirwan Nusyirwan Heru Syah Putra Cheng-Shane Chu

Unsaturated polyester (UP) composites are widely utilized in engineering applications, including vehicle body structures, due to their ease of processing and good interfacial compatibility with natural fibers. However, the inherent brittleness of UP limits its performance under impact or tensile loading, as it exhibits minimal plastic deformation and is prone to crack initiation and propagation. In this study, bamboo fiber was incorporated into the UP matrix at various mixing ratios to enhance its crack resistance. After achieving uniform dispersion, the composites were subjected to a splitting tensile test to evaluate their crack resistance behavior. The results indicate that the composite containing 80% polyester exhibits the highest fracture toughness, with a crack resistance value of K1C = 1.396 MPa·m0.5. This value represents a 192.03% improvement compared with neat polyester (K1C = 0.713 MPa·m0.5). The enhanced crack resistance is attributed to the fiber bridging and energy-absorption mechanisms introduced by the bamboo fibers. These findings demonstrate the effectiveness of bamboo fiber reinforcement in improving the fracture performance of UP-based composites, highlighting their potential for use in lightweight structural applications.

Journal of Composites Science doi: 10.3390/jcs10060300

Authors: Amber M. Hubbard Caitlyn M. Clarkson Emma E. Drake Ana G. Colliton Sanjita Wasti Katie Copenhaver Matthew Korey Carl P. Tripp Michelle K. Kidder Halil Tekinalp Soydan Ozcan

Cellulosic fibers can impart many unique benefits into composite applications, such as reduced weight or structural reinforcement; however, these materials also increase hygroscopicity and decrease thermal stability, restricting broader applications. The present work adapted an experimental process for functionalizing the cellulose surface using citric acid (CA) for three fibers: a 100% cellulose bleached soft Kraft pulp (e.g., creafill) and two natural fibers with similar composition but different fiber morphology, flax fiber and banana fiber. The process uses CA with a sodium hypophosphite (SHP) catalyst to chemically functionalize fiber surfaces, and the reaction mechanism was investigated through Fourier Transform Infrared Spectroscopy (FTIR), which suggested a grafting mechanism rather than a surface-based crosslinking between neighboring sites. Functionalized fibers were compounded into polylactic acid (PLA) at 20 wt.% to better understand how this functionalization might impact critical performance properties like thermal stability, crystallization, thermal mechanical properties, and water uptake of these composites. The study demonstrated varying levels of efficacy for the functionalization of cellulosic fibers with CA/SHP and the fiber with the most open microstructure, e.g., banana fiber, exhibited the largest change in its properties with a 38% reduction in water uptake compared to untreated banana fiber composites. Parallel evaluation of the functionalization process for different fibers demonstrates the importance of fiber morphology on surface modification and can enable their use in composites by demonstrating the efficacy of this potentially low-cost, low-toxicity method for reducing hygroscopicity and improving thermal stability.

Journal of Composites Science doi: 10.3390/jcs10060299

Authors: Ang Li Feyi Adekunle Rahul Vallabh Abdel-Fattah M. Seyam

Woven fabric-reinforced laminates (FRLs) are widely used in flexible composite structures where fabric-adhesive bonding strongly influences load transfer, energy dissipation, and structural integrity. Recently, our team developed a yarn pullout in laminate (YPiL) test for bonding assessment in woven FRLs to overcome the limitations of the cumbersome T-peel test, with a focus on maximum pullout force. This study advanced the YPiL with an energy-based framework in which the force–displacement curve is interpreted using three zones: bonding, interfacial debonding, and drag friction/sliding associated with four metrics: maximum pullout force (Fmax), pre-peak energy (E1), energy to the slope-break point (E2), and total pullout energy (Etotal). A dataset of 187 specimens covering four plain-woven Kevlar structures and five fabric-to-adhesive weight ratios (r = 0.67–2.83) was analyzed using a numeric general linear model (GLM). The dominant factor was r, with Fmax, E1, E2, and Etotal all decreasing as r increased. The interaction between pullout yarn width and r ranked second in every model, confirming a stronger r effect in fabrics with wider pullout yarns. The energy-based metrics, particularly Etotal, were more sensitive than Fmax to structural and bonding differences, and the Etotal model achieved R2 = 0.94 with Root Mean Square Error (RMSE) = 12.42 mJ.

Journal of Composites Science doi: 10.3390/jcs10060298

Authors: Haining Wang Xiangpeng Yan Qingming Wang Wenjuan Wu Yao Tian Qinsheng Xu

To address the durability limitations of conventional crack sealants under coupled extreme temperatures and traffic loads in long-life pavements, a bio-oil composite-modified patching material was developed using 90# base asphalt as the matrix, synergistically modified with crumb rubber (CR) and epoxidized soybean oil (ESO). To resolve the contradictory requirements for high elasticity and thermal expansion/contraction coordination in sealants, ESO was introduced; its polar epoxy groups optimize phase compatibility and promote low-temperature stress relaxation without restricting thermal deformability. Rheological evaluations revealed that the optimal system (OPT) successfully extended the service temperature window from PG 76–−24 °C (baseline) to PG 82–−24 °C, significantly enhancing its adaptability to extreme climatic fluctuations. At −24 °C, OPT exhibited a reduced creep stiffness (S) of 164 MPa and an increased creep rate (m) of 0.312, with a cracking resistance ratio (k) as low as 525.6; the quantitative significance of these metrics lies in granting the sealant superior stress relaxation capacity, enabling it to accommodate dynamic crack widening without interfacial debonding or brittle fracture. Fatigue testing via time sweeps demonstrated that Nf50 reached 2890 cycles, highlighting robust long-term resistance against high-frequency shear strains induced by tire edges. Micro-mechanistic analyses (FTIR, TG/DTG, and DSC) confirmed that the modification is primarily driven by physical blending. The elevation of the thermal decomposition threshold (T5%) to 302.4 °C and the residue at 600 °C to 44.8% provide a critical safety margin for high-temperature construction heating, preventing thermal degradation. Furthermore, the glass transition temperature (Tg) decreased to approximately −35.2 °C. These findings establish a rigorous quantitative and mechanistic framework for designing sustainable, high-performance patching materials for resilient pavement maintenance.

Journal of Composites Science doi: 10.3390/jcs10060297

Authors: Albertino Arteiro Daniel Alonso João Pedro Gabriel Soares Pedro P. Camanho Christian Karch

In protected carbon fibre-reinforced polymer laminates subjected to simulated lightning strike, while thermal effects mostly affect the topmost UD plies, damage in the bulk, where temperatures can be far from the ablation temperatures of the composite constituents, is mainly the result of the explosion of the lightning protection layer, the supersonic plasma expansion shock waves, and the magnetic forces. In this work, previously validated three-dimensional models are applied to the analysis of lay-up and stacking sequence effects on the mechanical damage induced by simulated lightning strike on carbon/epoxy multi-directional laminates and compared with experimental observations in the literature. This work demonstrates that those observations can be replicated by the proposed models, predicting the effect of lay-up and stacking sequence not only on the orientation of mechanical damage, but also on its size. In addition, no effect on damage depth is predicted, which is also in agreement with available experimental observations. Finally, the models predict that laminates with thicker ply blocks have larger mechanical damage projected areas, which is also in agreement with experimental observations in the literature. While the previous literature had focused on the effect of the lay-up and stacking sequence on thermally induced damage, this work is a first attempt to predict those effects on the mechanical resistance, which in the future will be key to assessing lightning damage tolerance in protected composite laminates.

Journal of Composites Science doi: 10.3390/jcs10060296

Authors: Redzuan Mohammad Suffian James Norwahyuni Mohd Yusof Liew Sze Ming H’ng Paik San

The growing demand for sustainable packaging materials has accelerated interest in biomass-derived carbon fillers as functional reinforcements for biodegradable polymer composites. This review critically evaluates the use of carbon materials produced from agricultural residues, particularly palm kernel shell (PKS) and coconut shell (CS), in biopolymer composite coating films for food packaging applications. Recent thermochemical conversion routes, including carbonization, activation, and catalytic graphitization, are discussed in relation to their influence on filler morphology, porosity, surface chemistry, and graphitic ordering. Particular emphasis is placed on structure–property relationships in composite systems containing matrices such as polylactic acid (PLA), starch, chitosan, gelatin, and polyvinyl alcohol (PVA). Published studies indicate that properly dispersed carbon fillers can improve tensile strength, thermal stability, ultraviolet shielding, and oxygen/water vapor barrier performance through stress-transfer mechanisms and tortuous diffusion pathways. However, excessive filler loading or poor interfacial compatibility frequently causes agglomeration, brittleness, and loss of transparency. Surface modification strategies including oxidation, silanization, and surfactant-assisted dispersion, are therefore reviewed as key approaches to optimize composite performance. Finally, current limitations involving migration safety, process scalability, and the lack of standardized testing protocols are discussed. Overall, PKS- and CS-derived carbon fillers represent promising sustainable additives for next-generation biopolymer composite packaging systems.

Journal of Composites Science doi: 10.3390/jcs10060295

Authors: Elīna Vīndedze Didzis Dejus Jānis Jātnieks Michael Folkert Telkamp Armands Leitans Janis Lungevics Behnam Boobani Tatjana Glaskova-Kuzmina

Materials applied in interior and non-structural aircraft components are required to satisfy rigorous safety and performance criteria, especially with respect to flame retardancy and wear resistance. Ultem 9085, a high-performance polyetherimide thermoplastic, is extensively used in aerospace applications owing to its advantageous strength-to-weight ratio and compliance with flame, smoke, and toxicity (FST) requirements. Nevertheless, the application of surface coatings, including paints, may modify their fire-retardant and tribological performance, with potential implications for service behavior and regulatory compliance. This work provides new insight into the behavior of painted Ultem 9085 components under fire exposure and frictional loading, addressing the critical need to determine whether surface finishing affects the material’s inherent performance advantages. Thus, the effects of different paint coatings on the fire-retardant and tribological properties of Ultem 9085 are investigated. Test specimens were manufactured using a Stratasys F900 system with 100% infill density and geometries adapted for standard vertical burn and heat release tests. Fire performance testing, including vertical burn, smoke and toxicity, and heat release rate, was performed in accordance with CS/FAR 25 Appendix F and AITM 3-0005 requirements. Tribological behavior was assessed using a ball-on-flat tribometer under dry-sliding conditions, while surface texture was analyzed using 3D profilometry. Seven polymer–coating composites were examined. It was experimentally confirmed that all coatings reduced vertical burn length but increased peak heat release rate and smoke density relative to unmodified Ultem 9085. Tribological results varied significantly, highlighting the critical role of paint selection in achieving optimal fire safety and wear resistance.

Journal of Composites Science doi: 10.3390/jcs10060294

Authors: Pyeong-Su Shin Yeong-Min Baek Seong Baek Yang Dong-Jun Kwon

Evaluation of fiber–matrix interfacial properties is essential for understanding composite performance and exploring the feasibility of real-time diagnostic approaches. In this study, the interfacial behavior between glass fiber and epoxy resin was examined using acoustic emission (AE) features obtained during microdroplet pull-out tests. Four AE features (amplitude, energy, rise time, and Fast Fourier transform peak frequency) were used as input variables to Random Forest models for both regression and classification tasks, targeting interfacial shear strength estimation and failure mode identification (interfacial debonding vs. fiber fracture). In regression analysis, energy and amplitude showed stronger associations with interfacial shear strength, although overall regression performance remained limited. In classification analysis, amplitude alone provided the most stable discrimination between fiber fracture and interfacial debonding, while combining multiple features offered only a marginal additional benefit due to feature redundancy. These results suggest that intensity-related AE parameters are closely associated with interfacial debonding behavior and failure modes. Overall, this exploratory study indicates that AE-based machine learning can serve as a supplementary tool for indirect and trend-level assessment of fiber–matrix interfacial behavior, with potential relevance to real-time monitoring applications.

Journal of Composites Science doi: 10.3390/jcs10060293

Authors: Binbin Xu Chaozhong Wang Yang Liu Jia Liu Changliang Xu Heming Wang Longgui Peng

Coal-fired fly ash poses both environmental challenges and resource utilization potential. In this study, a fly ash-based geopolymer ecological remediation material (MFA-MB) was synthesized from fly ash and bentonite through alkaline roasting activation, montmorillonite acidification, and alkali-activated polycondensation. The structural characteristics and Cr(VI) adsorption performance of MFA-MB were systematically investigated. Compared with raw fly ash, MFA-MB exhibited a more developed mesoporous structure, increased surface activity, and enhanced specific surface area from 19.473 m2/g to 30.813 m2/g. Adsorption experiments demonstrated that MFA-MB showed enhanced Cr(VI) adsorption affinity and rapid adsorption equilibrium behavior. The adsorption process was exothermic and likely involved combined physical adsorption and surface interaction effects. Field experiments further showed that MFA-MB effectively reduced Cr(VI) accumulation in Chinese cabbage while promoting plant growth. At the optimal dosage, Cr concentrations decreased from 0.145 mg/kg to 0.015 mg/kg in roots and from 0.081 mg/kg to 0.009 mg/kg in leaves. These results suggest that MFA-MB exhibits promising potential for fly ash resource utilization and Cr(VI)-contaminated soil remediation.

Journal of Composites Science doi: 10.3390/jcs10060292

Authors: Thomas Panagiotopoulos Ioannis Fillipos Kyriakidis Michel Theodor Mansour Constantine David Dimitrios Tzetzis Apostolos Korlos Konstantinos Tsongas

Dual-material additive manufacturing enables the design of cellular structures with a tailored mechanical response through controlled material distribution and interfacial architecture. In this research, honeycomb structures fabricated by Fused Filament Fabrication (FFF) using dual-material TPU/PLA configurations have been systematically investigated. Particular emphasis is placed on interlocking TPU/PLA joint designs, implemented through tau-shaped and teeth-based geometries, to evaluate their role in load transfer and structural performance. An experimental–analytical model has been developed to characterize the compressive force–displacement response of dual-material honeycombs, capturing the three characteristic deformation regimes—initial stiffness, progressive collapse, and densification—while linking the effective stiffness to the underlying beam-lattice mechanics. The relative contributions of axial and bending deformation mechanisms are quantified through a comparative beam element approach, introducing dimensionless coefficients that reflect the governing deformation mode. The results reveal that the mechanical response is bending-dominated for the examined configurations. The configuration with PLA at the nodes and TPU at the struts exhibits a higher load-carrying capacity and a more stable collapse regime due to a more balanced axial–bending interaction. In contrast, alternative material distributions lead to earlier instability and reduced structural efficiency. The proposed analytical model demonstrates excellent agreement with the experimental data across all configurations. The results demonstrate that properly designed dual-material interlocks can enhance load transfer, decrease stress concentrations, and refine the overall mechanical performance of lightweight cellular structures.

Journal of Composites Science doi: 10.3390/jcs10060291

Authors: Iacopo Bianchi Archimede Forcellese Chiara Mignanelli Michela Simoncini Tommaso Verdini

Fiber-reinforced polymer composites are widely used in industrial applications due to their high specific mechanical performance. In particular, carbon fiber-reinforced polymers (CFRPs) are most commonly used for automotive and aerospace sectors, but their production is energy-intensive and associated with relevant environmental impacts. Therefore, the interest in natural fibers is growing. Among them, basalt fibers are used as reinforcement of polymer matrix composites since the basalt fiber-reinforced polymers (BFRPs) exhibit good mechanical properties combined with a low ecological footprint. In this context, the present study provides a comparative experimental evaluation of CFRP and BFRP tubular components realized by means of a hoop filament winding process (winding angle equal to 88°). Radial and axial compression tests were performed according to ASTM D2412 and ASTM D695 standards to assess pipe stiffness, maximum compressive stress, and failure mechanisms. It was demonstrated that the fiber type strongly influences compressive behavior and damage mechanisms. Furthermore, the main results show that CFRP components are characterized by the highest pipe stiffness, approximately equal to 8.9 MPa with respect to 6.0 MPa of BFRP ones, while BFRP samples demonstrate a more elastic and progressive deformation behavior under radial loading. Both materials exhibit similar peak stress values under axial compression tests, equal to about 60 MPa, due to the load direction, which is perpendicular to the fiber orientation; thus, the mechanical properties are assimilable to those of the matrix.

Journal of Composites Science doi: 10.3390/jcs10060290

Authors: Nur Qudus Harianingsih Harianingsih Deni Fajar Fitriyana Virgiawan Adi Kristianto Dimas Gustoro Nabila Khoirunisa’ Kristian Saputra Jurina Jaafar Januar Parlaungan Siregar Sivasubramanian Palanisamy

Rice husk ash (RHA) is a silica-rich agricultural byproduct with significant potential in the development of sustainable porous materials. This study investigated the effect of calcination temperature and impregnation duration on the physicochemical and textural properties of KOH-modified RHA materials. The method used was calcination at different temperatures (500, 600, and 700 °C) combined with KOH impregnation for 19, 22, and 24 h. The prepared materials were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDX), Brunauer–Emmett–Teller (BET) surface analysis, and X-ray diffraction (XRD). FTIR analysis showed that increasing calcination temperature promoted the reduction in residual carbon-containing functional groups and enhanced the dominance of silica-related Si–O–Si vibrations. SEM observations revealed significant morphological evolution from heterogeneous fragmented structures at 500 °C to more interconnected porous frameworks at 600 °C, followed by partial densification and agglomeration at 700 °C. Semi-quantitative EDX analysis confirmed the silica-rich surface composition of the prepared materials, while XRD patterns indicated structural transformation from partially crystalline phases toward more stabilized silica-rich structures. BET analysis demonstrated that sample 2B, calcined at 600 °C with 22 h impregnation, exhibited the most favorable textural characteristics among the selected BET-analyzed samples, with the highest surface area and pore volume. Overall, calcination temperature and impregnation duration significantly influenced the structural evolution, pore development, and physicochemical characteristics of KOH-modified RHA materials. This study contributes to the development of sustainable biomass-derived materials and supports Sustainable Development Goal (SDG) 12, which is related to responsible consumption and production through the valorization of agricultural waste into value-added silica-rich materials.

Journal of Composites Science doi: 10.3390/jcs10060289

Authors: Zhiqiang Xia Suwen Chen Ziang Jin Kun Zhang Yongzheng Yan Yanghai Zheng

With the acceleration of urbanization and the rapid development of high-rise buildings, building fire safety has become an increasingly prominent concern. Traditional fire-resistant materials are no longer sufficient to meet the multifaceted requirements of modern architecture in terms of safety, energy efficiency, and aesthetics. This study innovatively develops an insulating composite fire-resistant glass. Through the design and optimization of the fire-resistant liquid type and the multi-layer composite structure, a synergistic enhancement in fire resistance performance, thermal insulation efficiency, and optical properties is achieved. Experimental results demonstrate that the insulating composite fire-resistant glass exhibits transparency comparable to that of commercial clear glass. More importantly, under standard fire resistance tests, it achieves a fire resistance rating exceeding 2 h, with a temperature rise on the non-fire side ≤ 100 °C. Furthermore, a series of composite fire-resistant glasses with varying fire protection grades can be fabricated as required. Its superior fire resistance is attributed to the unique tightly bonded porous interface structure, which effectively impedes heat conduction, thermal radiation, and heat convection. The design strategy and fabrication methodology presented in this study offer a novel technical pathway for advancing the building industry toward green development, demonstrating broad market application prospects and significant social benefits.

Journal of Composites Science doi: 10.3390/jcs10060288

Authors: Ahlam A. Abbood Ayad Al-Rumaithi Nazar Oukaili Abbas Allawi Amjad Albayati Teghreed H. Ibrahim Enas M. Mouwainea George Wardeh

Glass fiber–reinforced polymer (GFRP) reinforcement provides an effective alternative to conventional steel in concrete structures due to its corrosion resistance. Nevertheless, the lower elastic modulus of GFRP necessitates careful consideration of serviceability behavior in GFRP-reinforced concrete members. This study presents a numerical sectional analysis model for predicting the flexural response and ultimate capacity of hybrid reinforced concrete beams incorporating embedded GFRP profiles in combination with either mild steel or GFRP reinforcement bars under monotonic static loading. The proposed model employs realistic nonlinear stress–strain relationships for concrete and steel, together with secant moduli of elasticity evaluated at different loading stages. Particular emphasis is placed on detailed stress distribution in flexural sections, including the contribution of tension stiffening in the post-cracking regime. The formulation integrates nonlinear constitutive material behavior with theoretical sectional equilibrium to evaluate the effective flexural secant stiffness. For practical serviceability assessment and to reduce dependence on complex analytical procedures, strain vectors and stiffness matrix components are derived using elasticity coefficients that reflect modulus degradation obtained from numerical analysis. The accuracy of the model is verified through comparison with experimental results, including ultimate flexural capacity and moment–deflection responses. Many crucial parameters were studied, such as the longitudinal reinforcement ratio, type of reinforcement, concrete compressive strength, position of the I-GFRP profile, and rotation of the I-GFRP profile. The results of this study demonstrated that both the longitudinal reinforcement ratio and the rotation of the I-GFRP profile have a significant influence on the ultimate load capacity and deflection behavior. The close agreement between numerical predictions and experimental observations demonstrates the reliability and applicability of the proposed model for structural engineering analysis and design.

Journal of Composites Science doi: 10.3390/jcs10060287

Authors: En-Can Zhu Xiao-Yun Lan Zhen Chen Jin-Yu Yue Qi-Hang Yang Chuang-Nian Zhang

Myocardial infarction (MI) triggers excessive oxidative stress, a detrimental immune response, and insufficient angiogenesis, which collectively impede effective cardiac repair. This study developed a multifunctional composite polysaccharide hydrogel, termed KgXdgel, based on konjac glucomannan (KGM) and xanthan gum (XG) functionalized with gallic acid (GA) and dopamine (DA), respectively, to integrate reactive oxygen species (ROS) scavenging, macrophage polarization, and pro-angiogenic activities. In vitro assays demonstrated that the KgXdgel hydrogel exhibited excellent cytocompatibility, effectively scavenged ROS, promoted the polarization of macrophages towards the reparative M2 phenotype, and enhanced the migration and tube formation of human umbilical vein endothelial cells. In a rat MI model, treatment with KgXdgel significantly improved cardiac function (e.g., left ventricular ejection fraction, LVEF; left ventricular fractional shortening, LVFS), attenuated left ventricular dilation (LVIDs), and favorably modulated the post-infarction microenvironment. This was evidenced by the upregulation of the M2 marker CD163 and the angiogenic factor VEGF, alongside the downregulation of pro-inflammatory cytokines (e.g., IL-1β, TNF-α) and the M1 marker iNOS. These findings conclusively demonstrate that the KgXdgel hydrogel synergistically promotes cardiac repair post-MI through its integrated antioxidant, immunomodulatory, and pro-angiogenic functions, presenting a promising multi-targeted therapeutic strategy.

Journal of Composites Science doi: 10.3390/jcs10060285

Authors: Mahmoud Abo El-Wafa Mohamed A. Badran Ahmed S. Eisa Sara El Sayed Hilal Hassan

Since tires from end-of-life vehicles are not entirely biodegradable and pose a serious environmental problem, their disposal has become a significant global environmental concern. One technique to decrease these environmental issues is incorporating waste rubber to make sustainable green concrete. This study examined the usage of waste supplementary cementitious materials (SCMs) such as fly ash (FA), metakaolin (MK), marble powder (MP), slag (SL), and silica fume (SF) for surface precoating of crumb rubber (CR) to improve the mechanical properties of the produced crumb rubber concrete (CRC) by strengthening the bond between CR and cement paste in the interfacial transition zone (ITZ). The CR replaced (0, 15%, and 25%) of sand by weight in the preparation of CRC mixtures. A total of eleven CRC mixes were cast to investigate the fresh properties, compressive strength, and splitting tensile strength. In addition, the compressive stress-strain curve was investigated, and peak stress, peak strain, energy absorption, toughness, and modulus of elasticity have been evaluated. The outcomes showed that precoating CR using FA, followed by MK, has the strongest effect on increasing CRC compressive performance. The 25% substitution of sand with FA-treated CR increased compressive strength after 28 days, splitting tensile strength, peak stress, toughness, and modulus of elasticity by 34.7%, 23.7%, 34.8%, 26.1%, and 25.2%, respectively, in comparison to the same percentage of untreated CR. The proposed approach demonstrates a viable pathway for integrating waste materials and SCM-based technologies to develop high-performance, sustainable cementitious composites.

Journal of Composites Science doi: 10.3390/jcs10060286

Authors: Lorenzo Broggio Giacomo Moretti Sandra Dirè Andrea Dorigato

Polymer–ceramic piezoelectric composites are widely investigated to combine the high piezoelectric performance of ferroelectric ceramics with the flexibility and processability of electroactive polymers. However, achieving enhanced dielectric properties while preserving the intrinsic piezoelectric response of the polymer matrix remains challenging, particularly due to dielectric mismatch between the constituent phases and interfacial effects. In this work, barium titanate (BaTiO3) loaded poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) nanocomposites were fabricated by solvent casting using polyvinylpyrrolidone (PVP) and polysorbate 80 (PS80) as dispersing agents, aiming to obtain polarizable materials capable of retaining high piezoelectric strain coefficient (d33) values and potentially exploiting the opposite polarity of matrix and filler through tailored poling strategies. Morphological, crystallographic, structural, thermal, thermomechanical, dielectric, and piezoelectric characterizations were performed by SEM/EDXS, XRD, FTIR, DSC, TGA, DMTA, dielectric spectroscopy, and d33 measurements. Both dispersants improved filler dispersion and film densification, increasing the crystalline fraction of the matrix, without altering the relative fraction of β-phase (up to 93%). PVP enabled moderate and stable permittivity enhancement with weak frequency dependence, whereas PS80 introduced an electrically active interfacial contribution that amplified low-frequency permittivity at high filler loadings but made the permittivity more frequency-dependent. The piezoelectric response (between −20 pC/N and −25 pC/N) remained predominantly governed by the polymer phase, suggesting limited polarization played by BaTiO3. These results underlined the critical role of interfacial electrical properties in designing stable high-performance flexible PVDF-TrFE/BaTiO3 composites.

Journal of Composites Science doi: 10.3390/jcs10060284

Authors: Atared Salah Kawoosh Ahid Zuhair Hamoodi Mustafa Shareef Zewair Kadhim Z. Naser

Punching shear failure in reinforced concrete RC slabs is one of the most significant and detrimental failure modes due to its sudden nature and its dependence on a complex interaction between concrete strength, the reinforcement, and the loading conditions. In recent years, there has been increasing interest in utilizing sustainable cementitious materials and steel fibers as a way of enhancing structural performance and improving the durability of concrete. The study aims to assess the structural behavior of RC slabs utilizing a partial cement substitution with limestone powder (LP) and granulated blast-furnace slag (GBFS), with the addition of steel fibers. Twelve RC slabs were examined under uniform concentric loading to analyze cracking behavior, load–deflection relationship, stiffness variation, and ultimate punching shear strength. The results demonstrated that using limestone powder (LP) had a significant impact on the crack distribution pattern and resulted in a slight reduction in initial stiffness, with the load-bearing capacity decreasing to approximately 55.8% of the control mixture at high replacement ratios. Due to a slower hydraulic reaction than with other mixtures, increasing additional granulated blast-furnace slag resulted in a decrease in crack resistance and relative deformation. With a load-bearing capacity of approximately 92.9% of the control mixture, a tertiary mixture of limestone powder and granulated blast-furnace slag (GBFS) demonstrated a better balance in structural behavior, leading to improved crack control while maintaining a sufficient level of load-bearing capacity. The steel fibers also significantly contributed to enhanced post-cracking behavior by decreasing crack width and improving the stress redistribution mechanism within the RC slab. This led to increased punching shear resistance and enhanced energy absorption, with the ultimate load increased to 119 kN compared to the control mixture. Overall, the findings show that combining sustainable cementitious materials with steel fibers can effectively improve punching shear performance and enhance the efficiency and durability of reinforced concrete.

Journal of Composites Science doi: 10.3390/jcs10060283

Authors: Erica Magagnini Elisa Bettucci

Basalt fiber-reinforced polymer (BFRP) composites are increasingly considered as a sustainable alternative to traditional FRP systems for the strengthening of reinforced concrete (RC) structures, owing to their favorable mechanical properties, durability, and lower environmental impact. This study investigates the effectiveness of externally bonded BFRP strips for the strengthening of RC beam–column joints, with particular attention to the influence of strengthening layout on the structural response. An experimental program was carried out on full-scale RC beam–column joint specimens subjected to monotonic loading with load–unload cycles of increasing amplitude. Each specimen was first tested in its original configuration to induce controlled damage and subsequently strengthened using BFRP strips arranged according to two different layouts. This approach enabled a direct comparison between the behaviour of pre-damaged and retrofitted specimens and allowed the contribution of the BFRP reinforcement to be clearly identified. BFRP strengthening markedly improves joint performance, enhancing strength, ductility, and energy dissipation while limiting stiffness degradation. The results underline the critical role of the strengthening layout in governing the effectiveness of the composite system, as well as the influence of substrate cracking in the activation of the BFRP reinforcement.

Journal of Composites Science doi: 10.3390/jcs10060282

Authors: Harianingsih Harianingsih Deni Fajar Fitriyana Nur Qudus Januar Parlaungan Siregar Ade Mundari Wijaya Annisa Rifathin Zarlina Zainuddin Fitri Ayu Radini Raden Setyo Adji Koesoemowidodo Hosta Ardhyananta

This study investigates the effect of 3-glycidoxypropyltrimethoxysilane (GPTMS) concentration on the mechanical, interfacial, and fracture behavior of epoxy/microfibrillated cellulose (MFC) composites derived from oil palm empty fruit bunch (OPEFB). GPTMS was incorporated at 1, 3, and 5 Phr to improve compatibility between hydrophilic MFC and the hydrophobic epoxy matrix. Mechanical testing revealed that GPTMS concentration significantly influenced composite performance in a concentration-dependent manner, with 1 Phr GPTMS providing the most balanced reinforcement. At this concentration, tensile strength increased by 14.5% from 32.88 ± 3.61 MPa to 37.65 ± 1.42 MPa, while flexural strength improved by 5.55% from 70.24 ± 5.30 MPa to 74.14 ± 4.10 MPa compared with the unmodified composite. Tensile modulus also increased from 2.07 ± 0.06 GPa to 2.21 ± 0.16 GPa, accompanied by improved flexural modulus from 2.39 ± 0.12 GPa to 2.47 ± 0.21 GPa. SEM analysis revealed that the optimized formulation promoted more uniform MFC dispersion, improved interfacial integrity, reduced void formation, and enhanced fracture resistance through tortuous crack propagation, localized radial crack branching, and matrix tearing. In contrast, higher GPTMS concentrations (3 and 5 Phr) reduced mechanical efficiency, with flexural strength declining to 65.27 ± 5.33 MPa and 66.16 ± 4.23 MPa, respectively, due to increased fiber pull-out, interfacial heterogeneity, and more continuous crack propagation. FTIR analysis suggested possible silane-related interfacial modifications consistent with GPTMS incorporation, although these findings are interpreted as supportive rather than definitive evidence of grafting. Overall, the results demonstrate that moderate GPTMS incorporation (1 Phr) is the optimum strategy for enhancing epoxy/MFC composite performance, offering a practical pathway for developing sustainable lightweight bio-based composites with balanced strength, stiffness, and fracture resistance. This research contributes to SDG 12 (Responsible Consumption and Production) by promoting sustainable utilization of oil palm biomass waste for advanced engineering materials.

Journal of Composites Science doi: 10.3390/jcs10060281

Authors: Girts Kolendo Aleksandrs Korjakins Diana Bajare Genadijs Sahmenko

This research investigates the formation and behavior of sustainable crumb rubber-modified gypsum–cement–pozzolan (GCP) composites, with a view to their use in a broad concept for construction. GCP binders are gaining attention as a low-carbon replacement for Portland cement, and the addition of recycled rubber helps the achievement of circular economy goals and potentially increases durability. The present research evaluates the impact of crumb rubber (CR) on the mechanical strength, water absorption, dimensional stability, and freeze–thaw resistance of 3D-printed GCP-rubber composites. Composite blends of variable proportions of crumb rubber were prepared at constant binder ratios. Mechanical properties were defined by prism specimens (40 × 40 × 160 mm) by the flexural and compressive strengths, and deformation was determined by micrometers to measure longitudinal strain as a function of curing. Water absorption was determined prior to freeze–thaw cycling to define pore saturation. Durability was investigated using two approaches: (1) controlled freeze–thaw experiments on cube specimens, with XF1 grade performance achieved, and (2) ultrasonic pulse velocity (UPV) testing of specimens 3D-printed for assessing internal structural change after long-term frost exposure. Results showed that compressive strength decreased moderately (10–20%) with increasing rubber content from 17% up to 50%, while flexural strength improved up to 15%, showing the elastomeric action of CR. Water absorption was reduced by 5–8% in the rubber-modified blends due to the hydrophobic character of rubber. Deformation tests also confirmed minimum length variation (<0.02%) during curing. Freeze–thaw durability was enormously improved, and test specimens retained more than 95% of initial strength. UPV measurements detected only a relatively modest velocity drop (~50 m/s) after 36 days cycling with subsequent stabilization up to 200 days, demonstrating long-term internal structure with minimal progressive damage. In summary, the findings demonstrate that GCP composites with crumb rubber incorporated are printable, dimensionally stable, and capable of freeze–thaw degradation resistance. Despite a moderate loss of compressive strength, the balance of introduced durability and sustainability suggests their competence as viable materials for additive manufacturing in construction.

Journal of Composites Science doi: 10.3390/jcs10060280

Authors: Saja Al Ajrash Erick S. Vasquez-Guardado

Preceramic polymers, especially silicon oxycarbide (SiOC) and silicon carbonitride (SiCN) ceramics, have gained significant attention due to their wide range of applications in many fields, particularly in energy storage devices beyond conventional lithium-ion batteries (LIBs). This review focuses on the synthesis, structural characteristics, and properties of SiOC and SiCN ceramics as electrodes for battery applications. Furthermore, their promising applications as electrode materials for energy storage systems are explored, along with the most recent advances in the development of such materials and their use in lithium-ion batteries (LIBs), lithium-sulfur batteries (LSBs), potassium-ion batteries (PIBs), sodium-ion batteries (SIBs), and supercapacitors. This review addresses the distinct advantages of SiOC and SiCN ceramics, including high thermal stability, mechanical robustness, and adaptable microstructures. It also examines the challenges associated with the commercialization of these ceramics, including issues related to electronic conductivity and ion transport pathways.

Journal of Composites Science doi: 10.3390/jcs10050279

Authors: Wei Du Jun Liu Hao Song Minqiang Jiang Bo Ning Yang Yang Weiping Liu Keqing Han Hui Zhang Jianyong Yu

To investigate the resin infusion molding process for novel dry fiber-reinforced epoxy composite wing skin, dry fiber preforms were fabricated via an automated fiber placement (AFP) system, and the out-of-plane permeability of the preforms at different lay-up speeds was measured using the ultrasonic transmission method to determine the optimal lay-up parameters. A scaled-down composite wing skin structure was modeled and meshed via numerical simulation, and different resin infusion schemes were simulated and analyzed using PAM-RTM software. The optimal infusion scheme was determined by comparing the infusion time, infusion pressure and defect formation during resin flow for different schemes, and the wing skin component was fabricated through the vacuum-assisted resin infusion (VARI) process. Results indicate that the infusion time predicted by PAM-RTM simulation is 3883 s, while the actual measured value in the VARI process is 3611 s with an error of approximately 7% within a reasonable range. Both simulation and actual wing skin fabrication exhibited no significant defects, validating the accuracy of the three-dimensional permeability measurement of dry fiber preforms as well as the reliability of the simulation results.

Journal of Composites Science doi: 10.3390/jcs10050278

Authors: Zefeng Xu Linguo Liu Yi Yang Shi Liu Xinran Guo Tao Tao Banghua Du Jiaqiao Liang Peiyu Liu

This study investigates the coupled quasi-static response and stable-state switching behavior of mechanically prestressed rhombic bistable composite laminates under internal pneumatic pressurization and external mechanical loading. A rhombic bistable composite laminate with embedded fluidic channels is proposed, where pneumatic pressurization is employed to reconfigure the deformation state and modulate the coupling between the laminate morphology and external actuation loads. An efficient reduced-order analytical model is developed to capture the interactions among geometric configuration, prestrain distribution, internal pressure, and external mechanical loading, enabling the rapid prediction of the deformation evolution and load–deflection response under coupled loading conditions. The main innovation of this work is integrating rhombic geometric tailoring, intrinsic pneumatic actuation, and multimode external loading into a unified analytical framework. The results demonstrate that the interior angle, prestrain distribution, and loading mode can effectively regulate equilibrium morphology, snap-through energy, and actuation efficiency. Parametric analyses reveal that the rhombic geometry introduces pronounced shear–bending coupling, providing an additional geometric degree of freedom for tailoring bistable configurations and energy barriers. In particular, a smaller interior angle generally reduces the snap-through energy barrier, whereas front-side prestrain increases the energy required for stable-state switching by enhancing the initial curvature. Comparisons among different loading modes further show that transverse point loading provides the highest energy conversion efficiency, in-plane loading requires the largest input energy, and pressure-assisted actuation exhibits intermediate efficiency. These findings provide fundamental insights and practical design guidelines for programmable morphing and load-efficient stable-state switching for rhombic composite laminates operating under coupled internal–external loading environments.

Journal of Composites Science doi: 10.3390/jcs10050277

Authors: Viet-Tam Tran Thanh-Tung Pham Minh-Tu Tran Hoang-Nam Nguyen

This paper analyzes the vibrational characteristics of a novel sandwich plate configuration composed of an auxetic honeycomb (AH) core and laminated functionally graded carbon nanotube-reinforced composite (FG-CNTRC) face sheets, hereafter referred to as the SD-AuCNT plate. Based on Reddy’s third-order shear deformation theory (SDT), which accurately accounts for transverse shear effects without requiring shear correction factors, the equations of motion are derived using Hamilton’s principle and subsequently solved using a pb-2 Ritz formulation combined with the Newmark time integration scheme for dynamic response analysis. By combining an auxetic core with negative Poisson’s ratio characteristics and laminated FG-CNTRC face sheets featuring tailored CNT distribution patterns and orientations, the hybrid SD-AuCNT plate can improve structural stiffness, energy absorption, and dynamic performance; however, it has not been thoroughly investigated in the existing literature. After verifying the accuracy of the proposed computational procedure, the effects of auxetic core geometry, CNT distribution patterns, thickness ratios, and boundary conditions on the natural frequencies and transient responses of the plate are comprehensively investigated. The results provide new insights into the dynamic behavior of advanced sandwich plates and offer practical guidance for the design of high-performance lightweight structures in aerospace, marine, defense, and other engineering applications.

Journal of Composites Science doi: 10.3390/jcs10050276

Authors: Jagadesh Kannan Selvan Preethy Mary Arulanandam Sherine Stanly Madappa V. R. Sivasubramanian

This study presents a mechanics based analytical framework for predicting the flexural–shear capacity of reinforced concrete (RC) beams strengthened with Engineered Cementitious Composites (ECCs) and a hybrid ECC–GFRP near surface mounted (NSM) system. Building upon previously reported experimental observations, the present work aims to establish rational prediction models capable of capturing the interaction between flexural and shear mechanisms in strengthened beams. The analytical approach integrates sectional analysis for flexural capacity with a modified truss analogy for shear resistance, explicitly incorporating the strain hardening tensile contribution of ECC and the tensile and confinement effects of GFRP reinforcement. An interaction based failure criterion is subsequently employed to identify the governing failure mode under combined flexural shear actions. The proposed model is validated against experimental results obtained from twenty seven beam specimens with varying flexural and shear reinforcement ratios and strengthening configurations. The predicted ultimate loads show good agreement with experimental values, with an average deviation within ±10%. The analytical framework accurately captures the transition between flexural dominated, combined flexural–shear, and diagonal tension failures observed experimentally. Results demonstrate that ECC significantly enhances ductility and shear crack control, while the hybrid ECC–GFRP system provides substantial strength enhancement with a controlled shift in failure mode. Overall, the developed analytical models offer a reliable and computationally efficient tool for predicting the flexural–shear capacity and failure behavior of ECC and hybrid ECC–GFRP-strengthened RC beams, supporting performance based design and practical strengthening applications.

Journal of Composites Science doi: 10.3390/jcs10050275

Authors: Cihan Ciftci Hasan Tolga Altikaya

The increasing demand for sustainable and lightweight structural systems has motivated the development of alternative materials for wind turbine tower applications, where conventional steel structures are associated with high material consumption and environmental impact. In this study, a novel steel-reinforced recycled thermoplastic composite system is proposed as an alternative structural solution. To enable the design and practical application of such composite systems, the mechanical properties of the recycled thermoplastic matrix were experimentally characterized. Compression and tensile tests revealed average yield strengths of approximately 32 MPa in compression and 7.8 MPa in tension. To account for the environmental conditions encountered in field applications, the temperature-dependent mechanical behavior of the material was investigated. Since the critical mechanical response of the thermoplastic matrix in the composite system is governed by compression rather than tension, the study was limited to compression tests under elevated temperatures. The results show that the compressive yield strength decreases to approximately 31 MPa at 55 °C. An analytical model based on the transformed-section approach was also developed to predict the flexural behavior of the composite section and was validated through three-point bending tests, with an analytically predicted yield load of approximately 31.5 kN showing good agreement with experimental results. To assess structural applicability at a larger scale, a full-scale composite wind turbine tower was designed and manufactured, and its dynamic performance was evaluated through field measurements under natural wind loading conditions. The results indicate that the composite tower exhibits comparable dynamic behavior to a conventional steel tower, with a first natural frequency of approximately 3.08 Hz compared to 2.89 Hz for the steel tower, along with enhanced damping characteristics. These findings demonstrate that steel-reinforced recycled thermoplastic composites offer a promising and sustainable alternative for wind turbine tower applications, with potential for broader use in structural systems.

Journal of Composites Science doi: 10.3390/jcs10050274

Authors: Patrick S. Vieira Delma D. G. Rocha Bruno S. Teti Emanoel Laurertan T. França Nathan B. Lima Esdras C. Costa Erika P. Marinho Patrícia M. A. Farias Nathalia B. D. Lima

The design of sustainable composite materials requires approaches that integrate performance, durability, and circularity. In this study, jackfruit seed residue (JSR), a starch-rich agro-industrial by-product, is explored as a multifunctional biopolymeric component in cement-based rendering composites within a Safe and Sustainable by Design (SSbD) framework. Despite conventional strategies based on purified polymers or synthetic admixtures, JSR is incorporated in its unprocessed form, preserving its intrinsic chemical and structural heterogeneity and enabling complex physicochemical interactions within the composite matrix. Mortar formulations containing 0%, 3%, 5%, and 7% JSR (by binder mass) were evaluated through fresh-state, mechanical, and durability tests, combined with multiscale characterization (X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray fluorescence). The incorporation of JSR enhanced workability and significantly reduced capillary water absorption (up to 25.83%), while maintaining mechanical performance within the typical range for rendering applications, with strength gains observed at 28 days. The observed behavior is attributed to synergistic mechanisms, including water retention, internal curing, and microfiller effects, as well as ionic contributions from the mineral fraction of the residue. Further, microstructural analysis revealed refinement of the interfacial transition zone and modification of the pore network, indicating reduced transport connectivity rather than a simple decrease in total porosity. These results demonstrate that unprocessed bio-residues can act as effective multifunctional components in cementitious composites, enabling the tuning of structure–property relationships and offering a scalable pathway toward low-impact composite materials aligned with circular economy principles.

Journal of Composites Science doi: 10.3390/jcs10050273

Authors: Alina Rabadanova Abdulatip Shuaibov Asiyat Magomedova Nariman Alikhanov Shikhgasan Ramazanov Akhmed Amirov Dinara Sobola Samer Daradkeh Tomáš Trčka Kamaludin Abdulvakhidov Arseniy Khrustalev Farid Orudzhev

Multifunctional polymer–ferrite composites based on poly(vinylidene fluoride) (PVDF) and magnetic fillers are of increasing interest for applications requiring coupled electrical, dielectric, and magnetic responses. However, the relationship between magnetic filler concentration, PVDF phase composition, and the resulting multifunctional properties remains insufficiently understood. In this work, PVDF/BaFe12O19 (PVDF/BaF) composite membranes containing 2–20 wt.% BaF were fabricated using a combined non-solvent and thermally induced phase-inversion (NIPS–TIPS) method. Structural evolution was analyzed by X-ray diffraction and quantitative FTIR spectroscopy, thermal behavior by differential scanning calorimetry, optical properties by diffuse reflectance spectroscopy, dielectric response in the frequency range 103–106 Hz, and magnetic characteristics by vibrating sample magnetometry. At moderate filler concentrations (2–10 wt.%), BaFe12O19 nanoparticles acted as effective β-phase nucleating centers, leading to electroactive phase fractions of 97.7–99.9% and a maximum β-phase content of 86.7% for PVDF/BaF10. At higher loadings (15–20 wt.%), particle agglomeration and restricted chain mobility promoted a transition toward α-phase-dominated crystallization. Thermal analysis indicated competing nucleation and confined crystallization processes, while optical and dielectric measurements revealed nonmonotonic changes associated with interfacial interactions and Maxwell–Wagner–Sillars polarization. Magnetic measurements showed a linear increase in saturation magnetization with filler concentration and a nonmonotonic coercivity dependence with a pronounced change near the critical agglomeration concentration. These results demonstrate that the multifunctional response of PVDF/BaFe12O19 membranes is governed by the interplay between β-phase nucleation, interfacial polarization, and magnetic particle interactions, with approximately 10 wt.% ferrite providing the most balanced electrical, dielectric, and magnetic characteristics.

Journal of Composites Science doi: 10.3390/jcs10050272

Authors: Chen Chen Xiuxin Yang Dan Yao Chuan Zeng Bokai Liu

The free vibration of functionally graded (FG) beams under thermal environments is fundamental to understanding forced vibration, flutter, and thermal buckling in high-temperature structures. However, current research primarily focuses on theoretical modeling and numerical solutions, with limited mechanistic insights into temperature-dependent frequency variations and multi-factor effects. This study presents an analytical investigation coupled with experimental validation to characterize the vibration behavior of FG beams under thermal environments. First, governing equations for thermal vibration of FG beams are derived under uniform, linear, and nonlinear temperature fields based on the power-law assumption, the rule of mixtures, Timoshenko beam theory, and Hamilton’s principle. Subsequently, analytical expressions for natural frequencies and mode shapes are obtained using the state-space method. Then, experimental validation is performed to verify the model’s accuracy. Finally, the combined effects of temperature field, power-law index, slenderness ratio, and boundary conditions on the natural frequencies are systematically analyzed.

Journal of Composites Science doi: 10.3390/jcs10050271

Authors: Longbang Qing Jinxin Meng Qifeng Gu Mengdi Bi

In this study, the two-dimensional aligned steel fiber-reinforced micro-expansive concrete (2D) was prepared, aiming to address the inherent vulnerabilities of concrete, such as early-age shrinkage cracking and low tensile ductility. For this purpose, the steel fibers and expansive agent were utilized. Furthermore, the planar rotating magnetic field was used to randomly distribute the steel fibers in a two-dimensional plane. In order to verify its superior mechanical and shrinkage properties, the compressive, fracture and drying shrinkage tests were carried out. The results demonstrate that the 2D alignment method enhances the fiber utilization efficiency. Compared with fiber-free groups, the compressive strength and fracture parameters of specimens incorporating steel fibers were improved. Furthermore, compared with randomly distributed steel fiber-reinforced micro-expansive concrete (RD), the 2D alignment method made the cubic compressive strength and fracture energy improve 8–14.2% and 19.4–110%, respectively. Additionally, the advantage of the fiber 2D alignment method was also reflected in the inhibition of drying shrinkage. Compared with normal concrete, the 180-day shrinkage strain of the 2D1.2 group was reduced to 200 με (only 19.5% of that of normal concrete, or 30.6% of that of micro-expansive concrete). Mechanistically, these superior performances are fundamentally governed by a coupling effect: chemical shrinkage compensation and physical alignment constraint.

Journal of Composites Science doi: 10.3390/jcs10050270

Authors: Basim Alfajri Samah Daffalla Hessah Alzouraiq Salman Bin Maan Ahmed Alfuzaya Mohamed R. El-Aassar

A major challenge in wastewater treatment lies in developing cost-effective and sustainable adsorbent materials for efficient dye removal. In this study, a novel biochar functionalized with MgO nanoparticles derived from palm leaf waste (MgO/PLB nanoparticles) was synthesized and evaluated for the removal of Congo red (CR) from aqueous solutions. FTIR, SEM, BET, and TGA investigations were used to thoroughly analyze the produced nanocomposite’s physicochemical properties. FTIR analysis verified the successful incorporation of MgO nanoparticles, as evidenced by the presence of characteristic Mg–O vibrations and noticeable changes in surface functional groups. SEM analysis revealed a transformation from a compact structure to a rough, particle-decorated morphology, indicating increased surface heterogeneity. BET analysis indicated the development of mesoporous structures, accompanied by a substantial increase in specific surface area from 2 to 178 m2/g. TGA results further confirmed enhanced thermal stability, indicating the formation of a structurally robust adsorbent. Batch adsorption tests showed that CR removal depends on pH, dosage, concentration, and contact time, with maximum efficiency (~99%) achieved at pH 4 using 0.03 g of adsorbent. The adsorption followed pseudo second order kinetics and was best described by the Langmuir isotherm, with a maximum capacity of 23.4 mg/g. The regenerated nanomaterial retained more than 89% of its adsorption capacity after four successive cycles, demonstrating good reusability and stability. The developed MgO/PLB nanoparticles exhibit efficient adsorption performance, combined with low-cost synthesis and the utilization of abundant agricultural waste, making it an affordable and long-lasting adsorbent for applications involving wastewater treatment.

Journal of Composites Science doi: 10.3390/jcs10050269

Authors: Jie Ding Jinming Cao Jiancheng Cao Jun Zhang Jingli Yan Hui Ding

Composite hydrogen storage vessels exhibit pronounced anisotropy, multilayered winding architectures, and strong ultrasonic attenuation, which severely degrade the focusing accuracy and defect visibility of the conventional isotropic total focusing method (TFM). To address these challenges, this study proposes an enhanced TFM framework for defect inspection in composite hydrogen storage vessels by integrating anisotropic delay correction, Gray-code coded excitation, and coherence-weighted reconstruction. First, an anisotropic propagation delay model is established using forward ray tracing to compensate for beam deviation and focusing mismatch induced by the anisotropic winding structure. Then, Gray-code excitation and pulse compression are introduced to improve signal energy and echo detectability under high-attenuation conditions. Finally, coherence-weighted imaging is applied to suppress incoherent background noise and structural artifacts, thereby enhancing defect contrast and image readability. The proposed method is validated on hydrogen storage vessel specimens containing artificial defects, with CT results used as references. Experimental results show that, compared with conventional isotropic TFM, the proposed collaborative approach significantly improves defect imaging quality for defects of different sizes and depths. The signal-to-noise ratio is increased from 7.2, 12.8, 14.8, and 7.4 dB for isotropic TFM to 32.5, 29.9, 52.6, and 42.7 dB, respectively, for the combined anisotropic, coded-excitation, and coherence-weighted TFM. In addition, the defect depth estimation remains stable and agrees well with the CT references, yielding approximately 9.0–9.6 mm for shallow defects and 18.7–19.3 mm for deeper defects. These results demonstrate that the proposed method can effectively improve defect detectability, image contrast, and depth characterization for embedded delamination-like artificial defects in composite hydrogen storage vessels, providing a promising ultrasonic imaging strategy for thick-walled anisotropic composite pressure structures.

Journal of Composites Science doi: 10.3390/jcs10050268

Authors: Majed Alowaid Tannaz Tayyarian Iriana García Guerra Maria Alexandra Erquiaga Nader Alhabradi Pythagore L. Kyabutwa Abdulrahman S. Binfaris Shouzhong Zou Omar Rodríguez Uicab Jandro L. Abot

Carbon nanotube yarn (CNTY) monofilament composites were investigated for integrated temperature sensing by embedding a single CNTY in a vinyl ester resin (VER) and measuring the electrical resistance change by tapping into the thermoresistive response of the CNTY. The effect of curing condition on the thermoresistive response was evaluated using dwell tests and repeated heating–cooling cycles, comparing specimens cured at room temperature (RT) with those post-cured at 140 °C for 1 h. RT-cured CNTY/VER monofilament composites exhibited electrical resistance drift, with the resistance failing to return to its initial value after each thermal cycle, resulting in a residual resistance change of ~8.85%. In contrast, post-cured (PC) specimens showed a much smaller residual change (−0.08%) after cycle completion. Thermal cycling from RT (~25 °C) to 100 °C produced a nearly linear negative thermoresistive response. The average heating and cooling TCR values were −7.98 × 10−4 °C−1 and −8.32 × 10−4 °C−1 for CNTY/VER, and −7.93 × 10−4 °C−1 and −7.13 × 10−4 °C−1 for CNTY/VER-PC, respectively. The hysteresis decreased from 21.65% for RT-cured specimens to 12.49% after post-curing, accompanied by improved linearity. The influence of heating rate on TCR was also examined for both freestanding CNTYs and CNTY/VER monofilament composites. The observed response is attributed to coupled matrix–yarn effects (wetting, resin infiltration, and shrinkage) together with temperature-dependent electron transport across CNT junctions. Finally, CNTY/VER monofilament composites demonstrated the ability to estimate internal temperatures under various thermal programs.

Journal of Composites Science doi: 10.3390/jcs10050267

Authors: Tsung-Yen Tsai Basharat Hussain Hsu-Heng Chien Naveen Bunekar

This experimental study systematically explores the impact of particle size variation in Layered Double Hydroxide (LDH) composites on the thermomechanical and optical properties of poly(methyl methacrylate) (PMMA) nanocomposites. Utilizing a co-precipitation method, LDHs modified with cocamidopropyl betaine (CPB) were synthesized in three distinct sizes (small 80 nm, medium 130 nm, and large 280 nm) and then incorporated into a PMMA matrix through bulk polymerization using Benzoyl Peroxide as the initiator. Morphological analysis via electron microscopy confirmed the exfoliation of LDHs layers within the PMMA matrix, indicating effective dispersion. The medium-sized LDH/PMMA nanocomposite exhibited enhanced interlayer interactions, facilitating polymerization and increasing the thermal degradation onset temperature by 21.2 °C compared to pristine PMMA. In contrast, the small-sized LDH/PMMA nanocomposite demonstrated a significant improvement in mechanical performance, with a 62% increase in storage modulus, attributed to its higher aspect ratio and improved stress transfer. Additionally, the optical transmittance of the nanocomposites across a visible range of 550 nm exceeded 88%, suggesting a minimal impact on optical clarity despite varied particle sizes. Overall, the incorporation of size-specific LDHs modifications led to notable enhancements in both the thermal stability and mechanical performance of the PMMA nanocomposites, underlining the potential of tailored nanoparticle modifications in advanced polymer matrices.

Journal of Composites Science doi: 10.3390/jcs10050266

Authors: Victor Hugo Viera de Oliveira Araujo Igor da Silva Brum Carlos Nelson Elias Lucio Frigo Ana Lucia Rosa do Nascimento Mario José dos Santos Pereira Bianca Torres Ciambarella Marco Antônio Alencar de Carvalho Jorge José de Carvalho

In medicine and dentistry, bone-loss treatment often uses hydroxyapatite combined with collagen membranes. The biocompatibility of these biomaterials depends on their composition and physical/mechanical properties. In this study, a graft composed of synthetic hydroxyapatite nanoparticle (Blue Bone®) and a bovine type I collagen membrane (Green Membrane Perio®) was developed compared with commercial Bio-Oss® graft and Mucograft® membrane. The materials were characterized by roughness, wettability, tensile testing, DSC, SEM, and TEM. In vivo, temporoparietal bone defects were created in 40 Wistar rats divided into five groups (n = 8): sham (no biomaterial); Bio-Oss®; Bio-Oss® + Mucograft®; Blue-Bone®; and Blue-Bone® + Green Membrane Perio®. Immunohistochemistry showed Green Membrane Perio® was made of thin, well-organized type I collagen fibers and was free of contaminants. Immunohistochemistry, histology, and immunohistochemical analyses indicated that Blue Bone® and Green Membrane Perio® were biocompatible and supported tissue regeneration. The Blue Bone® groups demonstrated higher collagen content than the Bio-Oss® + Mucograft® group. Quantitative and qualitative outcomes included morphological, thermal, mechanical, and surface property measurements, as well as cellular compatibility testing. The results showed comparable wettability and surface roughness, adequate membrane tensile strength, osteoconductive nanoparticle morphology, no adverse inflammatory reactions, and similar new bone formation metrics compared with controls. In conclusion, the combination of synthetic hydroxyapatite nanoparticles (Blue Bone®) and a bovine type I collagen membrane (Green Membrane Perio®) showed good performance when compared to established products and was considered safe and biocompatible for bone repair applications.

Journal of Composites Science doi: 10.3390/jcs10050265

Authors: Nikolaos Ploumis Georgios N. Mathioudakis Anastasios C. Patsidis Georgios C. Psarras

Nanocomposites consisting of titanium carbonitride nanoparticles (TiCN) and epoxy resin were fabricated and studied as the filler content was varied. Nanocomposites’ structural investigation was conducted via X-ray Diffraction technique (XRD), while their morphology was examined by employing Scanning Electron Microscopy (SEM). Viscoelastic mechanical properties were assessed by Dynamic Mechanical Thermal Analysis (DMTA). Results revealed the reinforcing ability of TiCN nanoparticles. The dielectric characterization of the nanocomposites was carried out using Broadband Dielectric Spectroscopy (BDS) over a wide frequency and temperature range. Dielectric spectroscopy revealed two relaxation processes related to the polymer matrix: the α-relaxation, associated with the glass-to-rubber transition, and the β-relaxation, associated with the rearrangement of side polar groups. In addition, in the low-frequency–high-temperature region, interfacial polarization (IP) was observed. IP is related to the presence of nanoparticles and to the accumulation of unbound charges at the system’s interface and includes contributions from a dipolar process and charge migration (conductivity). Alternating current conductivity generally increases with filler content, though it is also affected by frequency and temperature. Conductivity could influence Electrode Polarization (EP), which often masks the dipolar process of IP. A simple method for removing the EP effect is formulated and tested.

Journal of Composites Science doi: 10.3390/jcs10050264

Authors: Paniti Moolpradab Montree Hankoy Jianfeng Zhang Nittaya Keawprak Mettaya Kitiwan Phacharaphon Tunthawiroon

The utilization of locally sourced raw materials for lightweight aggregate (LWA) production has attracted increasing attention due to its potential for cost reduction and sustainable material development. This study investigates the effect of expanded perlite addition (10–40 wt%) on the physical, structural, and mechanical properties of LWAs derived from In Buri red clay, sintered at a relatively low temperature of 800 °C without a conventional high-temperature bloating process. X-ray diffraction (XRD) analysis revealed that quartz remained the dominant phase after sintering, with minor albite and residual illite, indicating limited phase transformation. Thermal analysis showed that major mass loss occurred below 600 °C, confirming that 800 °C is sufficient for removing volatile components. SEM observations demonstrated that increasing perlite content led to the development of a more porous and interconnected microstructure. As the expanded perlite content increased, the bulk density decreased from 1.31 to 0.80 g/cm3, while the apparent porosity and water absorption increased to 48.5% and 60.8%, respectively. Conversely, crushing strength decreased due to increased porosity. These results demonstrate that expanded perlite is an effective additive for tailoring the microstructure and performance of LWAs at low sintering temperature. The developed materials show strong potential for horticultural applications.

Journal of Composites Science doi: 10.3390/jcs10050263

Authors: Anggun Tri Atmajayanti Yanuar Haryanto Hsuan-Teh Hu Fu-Pei Hsiao Gathot Heri Sudibyo Paulus Setyo Nugroho Laurencius Nugroho Nicolas Arya Baskara

This study involved a numerical parametric assessment of reinforced concrete (RC) T-beams strengthened with bonded steel wire ropes (SWRs), with the aim of evaluating the effectiveness of this strengthening system in terms of improving flexural performance. Since extensive experimental investigations are costly and time-consuming, a three-dimensional finite element model was constructed to represent the structural response of strengthened RC T-beams. This numerical model was verified using earlier experimental data to ensure its predictive capability for the flexural behavior of strengthened members. Following validation, the model was applied in a comprehensive parametric study to examine the effects of key design variables on structural performance. These variables included the SWR diameter, the compressive strength of the bonding mortar, and the strength of the bonding material. Their effects on load-carrying capacity, stiffness, deformation behavior, and energy absorption were systematically evaluated. The results indicated that SWR diameter was the dominant parameter, increasing ultimate load up to 1.93 times, with stiffness and energy absorption reaching 1.48 and 1.74 times those of the control beam, respectively. In contrast, higher concrete compressive strength provided moderate gains, with load capacity and stiffness increasing by up to 16% and 21%, while having a limited influence on ductility. Variations in bonding material strength showed minimal impact and negligible changes in stiffness. Strength and stiffness enhancements were accompanied by reduced ductility, indicating a trade-off between capacity and deformation. These findings confirmed that SWR efficiency was governed primarily by reinforcement size, while other parameters exhibited diminishing returns beyond threshold levels.

Journal of Composites Science doi: 10.3390/jcs10050262

Authors: Hind Fadhil Abbas Hasanain Radhi Radeef Salam Ridha Aletba Zaid Hazim Al-Saffar

The semi-circular bend (SCB) test is widely used to characterize asphalt mixture cracking resistance. However, the practical usefulness of the test depends on the reliability of the measured fracture parameters. This study investigates SCB testing from a reliability perspective, with the aim of identifying the specimen number required for dependable interpretation and the testing conditions that provide the most stable response. The analysis considered nominal maximum aggregate size, notch depth, binder type, aging condition, test temperature, and loading rate. Fracture energy, peak load, and flexibility index, together with their cumulative coefficients of variation, were tracked from n = 3 to n = 6, while six-specimen raw datasets were used for Weibull reliability analysis. The results show that notch depth had the clearest effect on response stabilization, with the 15 mm notch providing the most reliable configuration and reaching the adopted variability limits earlier than the other notch depths. The descriptive Weibull analysis further indicated that the SBS-modified mixture exhibited the highest fracture-energy consistency within the tested dataset, whereas long-term aging, testing at 0 °C, and loading at 50 mm/min were associated with the lowest fracture-energy consistency within the tested dataset. Overall, SCB interpretation should be guided by response reliability, not mean fracture parameters alone. On this basis, a reliability-based SCB framework is proposed to support more dependable mixture comparison and more rational specimen planning.

Journal of Composites Science doi: 10.3390/jcs10050261

Authors: Sanju Hanumantharayappa Mahendramani Gonal Siddeshkumar N. Gangadharaiah Jayant Giri Anupama Hiremath Suhas K. Mohammad Kanan

Metal matrix composites based on aluminum are frequently utilized in sophisticated engineering applications because of their improved mechanical performance. This study used the stir-casting method to create hematite (Fe2O3)-reinforced LM6 aluminum alloy composites with reinforcement ranging from 0 to 12 weight percent. At 3–6 weight percent reinforcement, microstructural examination showed uniform particle distribution and good interfacial bonding; at higher levels (9–12 weight percent), clustering and porosity were seen. While ductility declined with increasing hematite content, mechanical characteristics demonstrated a notable improvement in hardness and compressive strength, reaching maximum values at 12 weight percent reinforcement. At lesser amounts of reinforcing, heat treatment increased strength even more and partially recovered ductility. The range of 6–9 weight percent hematite was found to have the best balance between strength and ductility. These findings demonstrate the potential for enhanced structural performance of hematite-reinforced LM6 composites.

Journal of Composites Science doi: 10.3390/jcs10050260

Authors: Yevhen Chuprinov Kateryna Shmeltser Inna Trus Denis Miroshnichenko Liudmyla Lysenko Andriy Myronenko Mariia Shved Nataliia Hrudkina

This article examines the interaction of clay minerals with iron ore concentrate in the context of the efficient use of composite mineral resources. The role of the adsorption properties of mineral additives in the formation of interparticle bonds in green pellets is analyzed. Using X-ray diffraction (XRD) and infrared spectroscopy, the dehydration processes of Na- and Ca-montmorillonite were investigated, and the influence of the cation type on the minerals’ ability to retain water was established. The high thermal stability of the structural OH groups of montmorillonite from the IV-layer clay of the Cherkasy deposit was confirmed, which is an important factor during high-temperature processing of mineral raw materials. Electron microscopy results showed that the fourth-layer clay forms an optimal porous composite microstructure, which contributes to increased water-holding capacity and gas permeability of the pellets. A direct correlation between the adsorption capacity of mineral additives and the strength of raw and dried pellets was experimentally confirmed. Montmorillonite with palygorskite from Layer IV, characterized by high adsorption capacity and prolonged dehydration processes, was identified as the most effective composite binding additive. The results obtained deepen scientific understanding of the mechanisms underlying pellet strength formation and have practical significance for the rational and resource-efficient use of mineral resources in the production of iron ore pellets. The results also demonstrate the potential for improving resource efficiency in pellet production through reduced consumption of traditional binder materials.

Journal of Composites Science doi: 10.3390/jcs10050259

Authors: Rimma Tokinova Artem Rozhin Elvira Rozhina

This review highlights recent advances in clay-based nanocomposites for the remediation of algal toxins in aquatic environments. Particular emphasis is placed on hybrid materials derived from clay mineral nanoparticles with diverse morphologies that exhibit high efficiency in the adsorption and removal of cyanobacterial toxins, including microcystins, anatoxins, and motuporin. Owing to their large specific surface area, structural versatility, and tunable surface chemistry, clay minerals provide an effective platform for the design of functional nanocomposites capable of enhancing toxin capture and degradation. Recent developments in clay-integrated treatment systems are discussed.

Journal of Composites Science doi: 10.3390/jcs10050258

Authors: Tong He Shihao Zhu Zhiyu Zhang Zhongshan Ma Bin He Chao He Wanxiu Hai

Non-stoichiometric high-entropy carbides (Nb0.2Ta0.2Ti0.2W0.2Zr0.2)Cx (x = 0.71–0.85) nanoscale powders were prepared using oxides and carbon as raw materials via carbothermal reduction. The (Nb0.2Ta0.2Ti0.2W0.2Zr0.2)C0.73 synthesized at 1700 °C exhibited a grain size of approximately 400 nm, an oxygen content of 0.3 wt.%, and uniform nanoscale distribution of the five metal elements. After ball milling, (Nb0.2Ta0.2Ti0.2W0.2Zr0.2)C0.73 powder was sintered by spark plasma sintering to produce high-entropy ceramics with a relative density of 98.1% and an average particle size of about 5.3 μm. The Vickers hardness, nano-hardness, Young’s modulus, and fracture toughness were 17.6 GPa, 29.1 GPa, 514 GPa, and 5.3 MPa·m1/2, respectively. The thermal conductivity of the ceramic at room-temperature was as low as 8.5 W/m·K.

Journal of Composites Science doi: 10.3390/jcs10050257

Authors: Nikolay Sirotkin Anna Khlyustova Valeriya Aisina Anton Kraev Ruslan Kriukov Alena Shkapina Alexander Agafonov

This work presents a novel one-step plasma–solution synthesis of Prussian Blue (PB) and copper hexacyanoferrate (Cu-PBA) nanoparticles via underwater pulsed DC discharge. For the first time, the direct plasma-assisted formation of these coordination polymers is reported. The obtained materials were examined by X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, and scanning electron microscopy (SEM). These analyses confirmed that the desired phases had formed, along with small amounts of oxide byproducts (α-Fe2O3, CuO) arising from the erosion of the electrodes. Photocatalytic activity was evaluated through the degradation of organic dyes (Reactive Red 6C, Rhodamine B, and Methylene Blue) under UV-light irradiation. Both catalysts achieved complete dye degradation within 90 min of UV irradiation (after an initial 30 min dark adsorption step, total experiment time 120 min). Notably, selective performance was observed: PB exhibited higher activity toward the cationic dye Methylene Blue, while Cu-PBA was more effective for the anionic dye Reactive Red 6C. This selectivity is attributed to the specific oxide impurities forming heterojunctions that facilitate charge separation and generate distinct reactive oxygen species. The plasma–liquid method offers a rapid and environmentally benign route to functional PBA-based composites, with potentially scalable characteristics pending further engineering optimization. These findings highlight the potential of utilizing synthesis-induced impurities to tailor photocatalytic selectivity for water purification applications.

Journal of Composites Science doi: 10.3390/jcs10050256

Authors: Wenfeng Hao Jing Luo Lei Wu Yi Long Changfeng Qi Ben Wang

Acoustic emission (AE) was employed to characterize the mechanical behavior of repaired multi-layered woven lattice sandwich composite (MWLSC) in this paper. A patch repair strategy was adopted, in which damaged cores were reconstructed with polyurethane foam and fractured face sheets were restored using fiber fabric. Mechanical recovery was evaluated through mechanical testing, and AE monitoring was used to analyze damage evolution before and after repair. The repaired double-layered and triple-layered warp specimens recovered 123% and 104% of their original peak load, respectively, while the triple-layered weft specimen recovered 83%. Compared with pristine specimens, repaired MWLSC exhibited reduced cumulative AE counts and lower proportions of high-energy events. Continuous wavelet transform analysis revealed that the high-frequency components associated with interfacial delamination were significantly diminished after repair. These results indicate that repair modifies the dominant failure mechanism, shifting from delamination-dominated fracture toward core-related damage. The study demonstrates the effectiveness of AE techniques in capturing changes in damage evolution and mechanical response in repaired MWLSC.

Journal of Composites Science doi: 10.3390/jcs10050255

Authors: Gulstan Zhumabayeva Arthur Ukhov Shohreh Mashayekhan Maxim Susid Andrey Khlebnikov Abdigali Bakibaev Irina Kurzina Roza Ryskaliyeva Rakhmetulla Yerkassov

The surface functionalization of mesoporous bioactive glasses (MBGs) is of critical importance for the development of advanced hybrid biomaterials with controlled interfacial and adsorption properties. Composite systems based on MBGs modified with cucurbit[n]urils (CB[6], CB[7], and CB[8]) were synthesized and systematically investigated to elucidate size-dependent interaction mechanisms and their influence on textural and physicochemical characteristics. Functionalization was achieved via aqueous deposition followed by controlled thermal treatment. Nitrogen sorption analysis revealed distinct pore modification behaviors: CB[6] reduced the specific surface area by 64% with partial pore occupation; CB[7] induced extensive mesopore occlusion (92.4% surface area reduction); whereas CB[8] produced a balanced decrease (71.2%) while largely preserving microporosity. Thermogravimetric analysis demonstrated comparable loading for CB[7] and CB[8], yet MBGs@CB[8] exhibited enhanced thermal stability, with the DTG maximum shifted to ~395 °C. Molecular modeling supported these findings, indicating the lowest adsorption energy for CB[8]. This combination of structural preservation and enhanced stability provides the most favorable balance between pore accessibility and structural modification, demonstrating strong potential as a versatile modifier for subsequent functionalization, including drug loading applications in bone-regenerative systems.

Journal of Composites Science doi: 10.3390/jcs10050254

Authors: Nikolay Mukhin

Photonic and acoustic jets are subwavelength wave localization phenomena formed in the near field of dielectric or elastic scatterers, enabling spatial resolution beyond classical diffraction limits and motivating applications in sensing, imaging, and wave–matter interaction control. This review places photonic and acoustic jets in a unified wave-physics framework and focuses on how composite and layered elements can be used to tune their properties. In photonic systems, refractive index contrast, layer thickness, and optical losses play key roles, while in acoustic systems, acoustic impedance mismatch, dispersion, and viscoelastic damping are critical. Models and numerical approaches, and experimental realizations in both optical and acoustic regimes, are reviewed and summarized to describe jet formation and to analyze the influence of material parameters and geometry. The main findings show that layered and composite scatterers, such as core–shell particles, multilayer spheres and cylinders, and graded-parameter metamaterials, provide additional degrees of freedom for controlling jet intensity, length, focal position, and directionality compared to homogeneous elements. Composite jet-forming elements offer a versatile platform for advanced wave localization and hold promise for metastructures, high-resolution sensing, integration into photonic and acoustic devices, and lab-on-chip technologies.

Journal of Composites Science doi: 10.3390/jcs10050253

Authors: Hebatullah H. Farghal Tarek M. Madkour

A review on the structure, properties, sustainability, and life cycle analysis of basalt fiber composites, emerging as a major sustainable alternative to traditional synthetic reinforcements such as glass and carbon fibers. Basalt fibers (BFs) are high-performance mineral fibers derived from volcanic rock with a high silica content. These fibers exhibit superior mechanical strength, excellent chemical resistance, and exceptional thermal stability across a broad temperature range. This review explores the multi-sectoral applications of basalt fibers, particularly within the energy and chemical industries. Specific focus is placed on their role as reinforcing agents in concrete and polymer matrix composites, where they provide enhanced durability and corrosion resistance. Central to this discussion is the environmental profile of basalt fibers. We evaluate recent life cycle assessments (LCAs) that compare the environmental gains of BF-reinforced structures. The analysis extends beyond environmental metrics to include the economic and social pillars of sustainability, highlighting basalt’s cost-effectiveness in corrosive environments and its safety as a non-carcinogenic material. This review concludes that basalt fibers offer a significant “green” advantage, encouraging wider industrial adoption.

Journal of Composites Science doi: 10.3390/jcs10050252

Authors: Yuly Maldonado-Morales Rodrigo Ortega-Toro Joaquin Hernandez-Fernandez

Polylactic acid (PLA) is a biopolymer made from starch that is both sustainable and low-cost. But its chemical inertness limits its application in the removal of heavy metals from aqueous environments. This study addresses the limitations by functionalizing PLA with N-hydroxysuccinimide (NHS) and N-sulfosuccinimide (S-NHS). It is hypothesized that introducing the sulfonate group using S-NHS increases the electron-donating capabilities of PLA, optimizing its adsorption capabilities for heavy metals. Density Functional Theory (DFT) calculations of energy, optimization, frequencies and NBOs in Gaussian 16 (M05-2X/LanL2DZ) and Multiwfn 4.0 were used for the electronic properties of the pristine and functionalized polymer and their interactions with a simplified system of hexahydrated ions of nickel (Ni2+), arsenic (As3+), and lead (Pb2+) cations were analyzed. The results indicated that PLA-S-NHS has an energy gap (Egap) of 3.31 eV, being lower than that of PLA (5.51 eV) and PLA-NHS (4.42 eV), signaling an increase in its adsorption capabilities. Its total dipole moment (TDM) reached 196.16 Debye. The metal–polymer complexes exhibit high TDMs, such as 1104.78 Debye with Pb in PLA-S-NHS, confirming greater interactions. The NBO analysis shows that S-NHS functionalization strengthens the donor–acceptor interactions with the sulfonate group oxygens acting as a primary donor, enhancing the adsorption of heavy metals; this is shown by the adsorption energies (Eads), confirming that functionalization with S-NHS enhances the interaction with metal ions, with negative Eads values observed for all complexes, especially for Pb2+, indicating thermodynamically favorable adsorption. The functionalization with S-NHS optimizes the electronic properties of PLA for heavy-metal adsorption, thereby validating the hypothesis and providing a molecular basis for the rational design of advanced bioadsorbents. These results indicate the potential application of these functionalized PLA polymers, especially as membranes, for the selective extraction of heavy metals from aqueous solutions.

Journal of Composites Science doi: 10.3390/jcs10050251

Authors: Awad Jadooe Mushtaq Sadiq Radhi Zainab M. R. Abdul Rasoul Anmar Dulaimi Hugo Alexandre Silva Pinto Luís Filipe Almeida Bernardo Vitor Manuel Pissarra Cavaleiro

One definition of environmental sustainability is one that permits the maintenance of long-term environmental quality while preventing the depletion or degradation of natural resources. In the realm of concrete production, engineers are becoming more interested in sustainable development, which includes using locally available resources and repurposing industrial and agricultural waste in building construction as a potential remedy for economic and environmental problems. The purpose of the study is to determine how various ratios of waste steel and polypropylene fibers affect the compressive strength, tensile strength, flexural strength and density of reactive powder concrete composite at different ages. According to the test results, Mix 6, which contains 100% waste steel fiber and 0% polypropylene fiber, improves the mechanical properties of reactive powder concrete by 29% in compressive strength, 47% in tensile strength, 29% in flexural strength, and 6.1% in density when compared to the reference mix. Reactive powder concrete’s waste steel fiber content has been shown to effectively reduce cracking and increase splitting tensile strength. Statistical analysis using ANOVA and Tukey HSD confirmed that fiber type has a significant effect on the compressive strength of RPC, with mixes containing higher proportions of waste steel fibers demonstrating superior performance.

Journal of Composites Science doi: 10.3390/jcs10050250

Authors: Synthiya Senthilkumar Thirugnanam Thilagavathi Rethinavelu Renuka Uthrakumar Ramamurthy Kandhasamy Parasuraman Shaik Ashmath Seung Won Kim Shaik Gouse Peera

The SnO2-TiO2 binary nanocomposites’ metal oxide was synthesized by a co-precipitation method and potentially utilized for wastewater treatment applications. The average crystallite size, dislocation density, and micro strain of the synthesized nanocomposites were calculated by the Debye–Scherrer, modified Debye–Scherrer, and W–H methods. The nanocomposites exhibit a tetragonal crystal structure with 62% crystallinity. The presence of Ti–O–Ti and Sn–O–Sn bonds was identified using the FTIR technique. The surface morphology was examined during SEM and EDAX analyses. The optical properties were interpreted with the help of UV–Vis and PL spectroscopy, and the bandgap energy was ascertained. From the CV and EIS studies, the behavior of the diffusive and capacitive natures was determined. Photocatalytic studies were carried out under sunlight and UV light by degrading (cationic) malachite dye at concentrations of 10, 20, and 40 mg/L. When analyzed with seven kinetic models, it was inferred that a pseudo-second and first-order were followed under visible and UV light. The maximum degradation efficiency of 94% was achieved for the 20 mg/L dye concentration within 50 min under UV and 150 min under solar irradiation. Complete decolorization was observed for both 10 mg/L and 20 mg/L dye concentrations under both irradiations.

Journal of Composites Science doi: 10.3390/jcs10050249

Authors: Askar Chekimbayev Talgat Zhuniskaliyev Yerbol Kuatbay Almas Yerzhanov Nurbek Aitkenov Dauren Yessengaliyev Azamat Mukhambetkaliyev Yesmurat Mynzhassar

Along with the growth in the production of metallurgical grade silicon and high-silicon ferrous alloys, there is a significant increase in the formation of microsilica, which is an ultra-fine technogenic waste. The direct application of microsilica in ore-thermal furnaces is hindered by low bulk density, poor gas permeability, and high dusting. This paper explores the thermophysical and microstructure properties of briquettes based on microsilica, which includes various types of carbonaceous reducing agents such as semi-coke and coal. For manufacturing, the liquid glass was used as the inorganic binder for the preparation of microsilica briquettes. The best variants were chosen based on strength tests carried out during preliminary studies. In the laboratory tests, the stability of the briquettes at elevated temperatures was evaluated. Samples were heated to 1000–1500 °C and subjected to impact testing. Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS) was used to investigate the microstructure and local elemental distribution. It was revealed that the calcinated briquettes of the microsilica–semi-coke mixture have better thermal stability compared to the samples with coal and withstand the temperature range up to 1500 °C. The microstructure of the briquette from the microsilica-semi-coke mixture is characterized by the formation of a more uniform silicate matrix with the presence of a homogeneously distributed carbonaceous component. Coal-based samples show higher heterogeneity and porosity. Therefore, it can be stated that the selection of carbonaceous reductants is one of the key factors influencing the thermal stability of microsilica briquettes.

Journal of Composites Science doi: 10.3390/jcs10050248

Authors: Lu Zhang Pengbin Gao Yongjian Wu Fabo Liu Wenyue Huang Haiyan Mou Wenqing Chen

High-liquid-limit clay exhibits pronounced water sensitivity due to the strong electrostatic repulsion and weak interparticle bonding within its microstructure, which often limits its direct engineering uses and complicates the reuse of excavated clayey soils generated during the construction of transportation infrastructure. In this study, inorganic salts (KCl, CaCl2 and FeCl3) and carboxyl-containing polymers (PAAS, HPMA and CMC) were screened to construct organic–inorganic composite stabilization systems. Based on the screening results, an organic–inorganic composite system composed of CaCl2 and sodium polyacrylate (PAAS) was developed to regulate interfacial interactions and induce microstructural reconstruction in clay. The synergistic mechanisms governing particle aggregation and dispersion were systematically investigated through Atterberg limit tests, zeta potential measurements, DLVO theoretical calculations, particle size analysis, scanning electron microscopy (SEM) and immersion disintegration experiments, combined with multivariate statistical modeling. Among the tested salt–polymer formulations, a composite system with 2% CaCl2 and 0.1% PAAS showed the most favorable overall performance, achieving an optimal balance between electrostatic compression and steric stabilization, leading to enhanced structural integrity and delayed water-induced disintegration. Ca2+ ions compress the diffuse double layer and promote particle flocculation, whereas adsorbed PAAS chains introduce steric hindrance and interfacial modification. Their synergistic interaction reconstructs the pore–aggregate framework and regulates the interparticle potential energy landscape. DLVO analysis indicates that the optimized system attains a moderate critical interaction distance (hc = 7.31 nm) and primary minimum depth (DPM = −2.72 × 10−16 J), reflecting a balanced interfacial bonding state. Multivariate statistical analyses further reveal a dual control pathway, in which consistency primarily governs disintegration duration, with additional contributions from surface electrochemical properties, while surface properties, soil structure and consistency collectively influence disintegration initiation. These findings elucidate the interfacial regulation and structural evolution mechanisms in organic–inorganic composite systems and provide insights into the design of composite modifiers for water-sensitive particulate materials, particularly for the resource reuse of high-liquid-limit clay excavated during the construction of transportation infrastructure and related geotechnical engineering applications.

Journal of Composites Science doi: 10.3390/jcs10050247

Authors: Sanjay M. Sisodia Daniel J. Bull Andrew R. George Mark N. Mavrogordato S. Mark Spearing David T. Fullwood

This study presents a novel methodology integrating high-resolution X-ray computed tomography, digital volume correlation and statistical visualisation mapping, to perform microscale observations and correlate delamination fracture mechanisms in heterogeneous materials. To demonstrate the utility of this integrated approach, it is applied to study the damage behaviour of aerospace carbon/epoxy composite laminates with an open hole, subjected to quasi-static tension and fatigue at a load ratio of 1:10. The study also explores the applicability of a Paris law type relationship to determine effective macroscopic fatigue delamination resistance in the load-bearing plies. The X-ray imaging for both load cases revealed extensive formation of delaminated fracture surfaces surrounding both glass fibre interlacing weaves and entrained voids within them, acting as preferential sites for localised strain hot spots. It is demonstrated that local energy dissipation is governed by the recurring weave pattern and topological order, which can help explain the typical damage state in quasi-static behaviour, establishing a direct link between microstructural features and macrostructural material response.

Journal of Composites Science doi: 10.3390/jcs10050246

Authors: Ian R. Woodward Dominic J. Hoffman Catherine A. Fromen

Additively manufactured lattice structures have become a staple of optimized structural parts and are increasingly common in biomedical and chemical applications that require consideration of flow through porous architectures. However, design principles governing transport performance trail those established for mechanical optimization. Here, we introduce two complementary design frameworks that modify symmetry at both the unit cell and part scales to systematically tune internal transport. These approaches are further extended into patterned lattice structures, where multiple unit cell designs can be combined in one, two, or three dimensions to further regulate the internal flow. We find that identical global lattice geometries can arise from different unit cell basis and voxel plane orientations, with minimal changes in bulk geometric properties. Yet in parts with diameters of 12–35 mm, hydraulic diameters of 1–4 mm, and porosities ~80%, these design selections significantly affect the hydraulic tortuosity and fluid transport behavior. We further demonstrate performance from select designs that yield a new class of anisotropic lattices with strong sensitivity to flow direction that is tuned by the projected area perpendicular to flow. Collectively, these symmetry-informed, multi-order combinatorial design approaches enable predictable, direction-dependent transport design and expand the functional potential of lattice architectures across disciplines.

Journal of Composites Science doi: 10.3390/jcs10050245

Authors: Xuecheng Dong Liangzhu Yan Lingyun Wang Zhiyuan Zhou Youyan Jian Yahang Zhou

Deep hard-rock and geothermal drilling expose polycrystalline diamond compact (PDC) cutter chamfers to coupled thermal shock, abrasive wear, and intermittent impact, which accelerates edge spalling and degrades the quality of on-bit monitoring signals. This bench-scale proof-of-concept study evaluates a surface-gradient architecture that combines shallow cobalt leaching in the chamfer region with a thin silicon carbide (SiC) interlayer and a nanocrystalline diamond topcoat. Commercial 13 mm PDC cutters were treated within a surface-gradient design window of tSiC = 0–1.0 μm and LdeCo = 0–200 μm, and were examined by cross-sectional microscopy, XPS/ToF-SIMS, Raman stress mapping, scratch adhesion, apparent fracture toughness, laser-flash thermal transport, thermal-shock cycling, 400 °C pin-on-disc wear, instrumented impact loading, bench granite-drilling signal acquisition, and finite-element correlation. The optimized configuration (tSiC≈0.7μm, tD≈5μm, and LdeCo≈100μm) reduced the 95th-percentile tensile residual stress at the chamfer from about 0.48 to 0.26 GPa, reached a scratch critical load of about 28 N, compared with about 16 N for the topcoat-only condition and about 25 N for the SiC-plus-topcoat condition, cut high-temperature wear volume by about 40%, and shifted the characteristic spalling energy from about 0.8 to 1.3 J. In bench-scale granite drilling, the same design stabilized frictional response and improved simple pre-spall discrimination metrics, raising ROC-AUC from about 0.65 to 0.87. These bench-scale results provide proof-of-concept evidence that surface-gradient design can improve PDC chamfer durability and signal discriminability, while the proposed signal metrics have yet to be validated under field-scale downhole conditions.

Journal of Composites Science doi: 10.3390/jcs10050244

Authors: Jacob Samuel Abdirahman A. Yussuf Mohammad Al-Saleh Tahani Al-Shammary Rashed Al-Zufairi Aseel Al-Banna

This study investigated the comparative effects of various maleic anhydride-grafted polymeric compatibilizers such as polyethylene-graft-maleic anhydride, polypropylene-graft-maleic anhydride, polyethylene(alt)-graft-maleic anhydride and poly(styrene-ethylene/butylene-styrene)-graft-maleic anhydride on the final properties of polypropylene (PP) carbon nanotube (CNT) composites. Polypropylene nanocomposites (PP-CNT) were prepared by melt mixing using a laboratory scale twin-screw extruder. The mechanical test results showed that the incorporation of CNTs along with various compatibilizers increased the tensile strength (10.3%) and tensile modulus (24.2%). The tensile modulus and yield stress of the PP-CNT nanocomposites were significantly higher than those of the pristine PP. Differential Scanning Calorimetry (DSC) analysis revealed that the addition of CNTs slightly increased the melting temperature of the crystallization peaks. In the compatibilized PP-CNT composites, the CNTs were well dispersed to enhance the onset of degradation and maximum decomposition temperatures. The frequency-dependent rheological behaviors of PP-CNT nanocomposites indicated that the storage modulus (G′), loss modulus (G″), and complex viscosity (η*) PP increased for the compatibilized system. The XRD results indicated that the addition of CNTs and compatibilizers slightly affected the crystalline nature of PP. Scanning electron microscopic images of the fractured surfaces presented in the micrographs showed the brittle nature of the surface morphology of PP-CNT nanocomposites.

Journal of Composites Science doi: 10.3390/jcs10050243

Authors: Jéssica Mulinari Afonso Henrique da Silva Júnior Ellen Francine Rodrigues Carolina Elisa Demaman Demaman Oro Rodrigo Schlindwein Carlos Rafael Silva de Oliveira

Textile wastewater is among the most challenging industrial effluents due to its complex composition, high pollutant load, and low biodegradability. Conventional treatment methods often fall short in achieving complete removal of dyes and emerging contaminants. Photocatalytic composite membranes have emerged as a promising solution by integrating membrane separation and advanced oxidation processes. This review provides a comprehensive overview of the design, fabrication, and performance of photocatalytic composite membranes for textile wastewater treatment. Key aspects include the types of photocatalysts employed, methods of incorporation into membranes, and their synergistic role in pollutant removal and membrane fouling mitigation. Recent advancements in materials science, such as visible-light-responsive catalysts, carbon-based nanocomposites, and self-cleaning surfaces, are discussed, along with current limitations related to catalyst stability, operational scalability, and cost. This review underscores the potential of photocatalytic composite membranes as a next-generation platform for sustainable and effective textile wastewater treatment.

Journal of Composites Science doi: 10.3390/jcs10050242

Authors: Chensong Dong

Intralayer hybridisation provides a powerful strategy for tailoring the stiffness–strength–ductility balance of fibre-reinforced composites through architecture control. This study investigates the flexural behaviour of carbon/glass intralayer hybrid composites with varying carbon-to-glass (C:G) ratios and degrees of dispersion using a finite element modelling framework supported by experimental validation against published flexural test data. Four hybrid ratios (C:G = 2:1, 1:1, 1:2, and 1:4) and multiple dispersion levels were examined under three-point bending to quantify the effects of intralayer architecture on flexural strength, modulus, and strain to failure. The results show that carbon-rich hybrids retain high flexural stiffness and strength while achieving substantial improvements in failure strain and damage tolerance compared with pure carbon laminates. In these systems, flexural strength is strongly influenced by dispersion, with moderate-to-high dispersion improving strain compatibility, delaying tensile-side carbon fibre fracture, and enhancing strength. In contrast, glass-dominated hybrids exhibit flexural behaviour that is largely insensitive to dispersion, with strength and modulus following near rule-of-mixtures trends and failure governed by progressive glass fibre and matrix damage. Across all hybrid ratios, flexural modulus is controlled primarily by fibre volume fraction, whereas flexural strength and failure strain depend sensitively on intralayer architecture when carbon fibres remain the dominant load-bearing phase. These findings clarify the respective roles of hybrid ratio and dispersion in governing flexural performance and extend recent studies by demonstrating a systematic transition from dispersion-dominated to ratio-dominated behaviour as glass content increases. The results provide mechanistic insight and practical design guidance for optimising intralayer hybrid composites for lightweight, damage-tolerant structural applications.

Journal of Composites Science doi: 10.3390/jcs10050241

Authors: Arne Schiller Chiara Bisagni

Single-lap shear joints made from fabric T300/polyphenylene sulfide (T300/PPS) and unidirectional T700/low-melt polyaryletherketone (T700/LM-PAEK) laminates are joined via induction and conduction welding at different processing temperatures. The joints are tested experimentally to investigate the influence of the processing temperature on the damage evolution in the specimens which is tracked using digital image correlation. Cracks grow rapidly in the unwelded parts of the joint interface but assume a stable steady-state propagation rate when reaching the fully welded overlap region. It is found that higher welding temperatures lead to longer weld lengths, which improve the strength and stiffness of the specimens and delay damage initiation. An accelerated crack growth rate indicates that the structure is close to its ultimate load after which the joint fails abruptly as the crack growth becomes unstable. Induction welding temperatures at the upper end of the recommended processing window (330 °C for T300/PPS and 385 °C for T700/LM-PAEK) result in the joints with the highest load-carrying capacity and slowest crack propagation, but also the least damage tolerance.

Journal of Composites Science doi: 10.3390/jcs10050240

Authors: Arailym Imankulova Murat Alimkulov Baitak Apshikur Medetbek Kambarov Tolebi Myrzaliyev Daniyar Akhmetov Yelbek Utepov

Improving the durability of reinforced concrete sleepers is essential for railway infrastructure exposed to dynamic loading, moisture, and repeated freeze–thaw action. This study proposes a material-level modification approach for heavy concrete for type 2 reinforced concrete sleepers based on the combined use of activated microsilica, a ferroalloy-production byproduct, electrolyzed mixing water, and a polycarboxylate superplasticizer. The novelty of the work lies in the preliminary electrochemical activation of microsilica in an alkaline medium and in the optimization of its joint use with KN-5 by means of second-order experimental design. The concrete was evaluated by compressive and bending strength tests, scanning electron microscopy (SEM), water-penetration testing, and freeze–thaw resistance testing. All modified mixtures outperformed the reference concrete. The highest 28-day compressive strength reached 67.0 MPa, while bending strength reached 7.26 MPa. SEM observations showed a denser and more homogeneous cement matrix with reduced capillary porosity and improved interfacial transition zones. Water resistance improved from W8 for the reference mixture to W10–W14 for the modified concretes. Most modified mixtures achieved a frost resistance grade of F500, and the composition containing 15% activated microsilica and 1.0% superplasticizer reached F550. The proposed approach is effective at the material level for producing heavy concrete with enhanced strength and durability characteristics for reinforced concrete sleeper applications.

Journal of Composites Science doi: 10.3390/jcs10050239

Authors: Dauren B. Kadyrzhanov Rafael I. Shakirzyanov Kanat M. Makhanov Sofiya A. Maznykh Dilnaz K. Zhamikhanova

Due to the widespread use of microwave electromagnetic radiation, this study examines the microwave electromagnetic properties and compressive strength of composites made from inexpensive components such as Mg0.5Zn0.5Fe2O4, polystyrene, and activated carbon. Experimental samples were fabricated using thermopressing. The formation of the dielectric core/shell structure for Mg-Zn/polystyrene composites (1:1) and composites with activated carbon additives at weight concentrations of 3, 6.6, and 9.0% was determined using SEM image analysis. Microwave properties were investigated by analyzing the frequency dependences of complex permittivity and magnetic permeability in the frequency range of 100 MHz–5 GHz. As shown by the simulation and experimental measurements of scattering parameters obtained, the compost shows improved microwave absorption properties in the frequency range of 1–5 GHz. Reflection loss spectra showed peaks with values of −17.8 and −18 dB in the frequency range of 2.5–5 GHz for samples with 4.8 wt. % and 6.6 wt. % carbon loading, respectively. The absorption bandwidths of −10 dB in the range of 1.7–2.13 GHz were observed in the best samples. Studies have shown that samples containing 9.0 wt. % of carbon material with thicknesses of 6–10 mm can be considered as an electromagnetic shielding material in the microwave range 1–5 GHz. It was shown that, despite a decrease in porosity from 15.59 to 7.17%, with an increase in the concentration of carbon material in the composites, the compressive strength also decreases from 62.05 to 36.45 MPa. The developed composites are potentially suitable as microwave absorbers for civil applications.

Journal of Composites Science doi: 10.3390/jcs10050238

Authors: Francesca Ranellucci Gianfranco Ulian Daniele Moro Cesare Sangiorgi Giovanni Valdrè

The present study reports the variation of the mechanical properties of engineered metakaolin-based geopolymers synthetized using NaOH-KOH alkali activators and sodium disilicate, investigated after 7 and 28 days of aging by means of unconfined compression tests for mechanical strength analysis. The geopolymers were synthetized by mixing KOH and NaOH in different proportions in the alkaline activating solution, from 0% to 100% of KOH addition, fixing the Si/Al ratio and water content. The binders were synthetized with different curing temperatures. A novel composition using quarry-derived materials (silt from sedimentation lakes) was developed to realize an innovative composite. The materials were characterized by XRD, ESEM-EDS and unconfined compression tests. The mechanical results underlined that the addition of the filler tends to preserve the mechanical properties of the composite. Generally, curing at 40 °C followed by a 28-day aging period for the mixed Na-K geopolymers demonstrated the highest mechanical strength of all the synthesized products, with a maximum strength of 21 MPa. Mixed NaOH-KOH composites generally exhibited lower performances compared to sample consisting solely of 100% NaOH when cured at a temperature of 85 °C. Nonetheless, the synthetized composites reported in this study can have diverse applications across various technological fields requiring low-strength materials.

Journal of Composites Science doi: 10.3390/jcs10050237

Authors: Samara Araújo Kawall Nuelson Carlitos Gomes Diego Silva de Melo Dener da Silva Souza Ricardo Henrique dos Santos Naiara Lima Costa Camila Liendra Rausis Hiranobe Elmer Mateus Gennaro Flávio Camargo Cabrera Michael Jones da Silva Leandro Ferreira Pinto Erivaldo Antonio da Silva Carlos Toshiyuki Hiranobe Renivaldo José dos Santos

This study evaluated the partial and total replacement of zinc oxide (ZnO) with magnesium oxide (MgO) in styrene–butadiene rubber (SBR) composites, as well as the incorporation of ground tire rubber (GTR), aiming to develop more sustainable elastomer formulations. Ten formulations were prepared with varying ZnO/MgO ratios (100/0 to 0/100), with and without 20 phr of GTR. The composites were characterized by particle size distribution, morphology, rheometric behavior, density, crosslink density, mechanical properties, abrasion resistance, compression behavior, and thermo-oxidative aging. The results showed that hybrid ZnO/MgO activation systems exhibited a synergistic effect, enhancing vulcanization kinetics and mechanical performance compared to single-activator systems. Total replacement of ZnO by MgO was less effective, leading to reduced crosslink density and inferior properties. The addition of GTR increased compound viscosity and altered morphology but improved abrasion and compression resistance without significantly affecting tensile strength. Aging tests indicated good thermal stability, with maintenance or improvement of tensile properties due to post-curing effects. Overall, the combination of reduced ZnO content with MgO and GTR represents a viable approach for producing SBR composites with adequate performance and lower environmental impact.

Journal of Composites Science doi: 10.3390/jcs10050236

Authors: Angelo Angrisani Paolo Todisco Alessandro Pisapia Francesco Fabbrocino

This paper investigates the low-cycle behaviour of Concrete-Filled steel Tubes (CFTs) subjected to cyclic pure bending, a loading condition representative of large bridge and building girders. A 3D finite element model is developed in Abaqus/Explicit, combining a ductile damage law for the steel tube and Concrete-Damaged Plasticity for the infilled concrete, and is calibrated against large-scale cyclic bending tests on circular and square CFT beams. An automated Python scripting framework is then used to perform a systematic parametric study on members made of standard code-based materials, varying diameter-to-thickness ratio and span length over a wide range of practical configurations. Constant-amplitude chord rotations are imposed, and the nonlinear response is tracked in the plastic range while material damage evolves. The hysteretic behaviour is quantified in terms of cumulative plastic strains, dissipated energy and the degradation of reaction force and bending moment after 25 cycles. The results show that geometric parameters strongly affect the cyclic response: within the investigated loading layer, configurations with De=100 mm generally exhibit strength degradation values between about 10% and 60%, whereas for De=400 mm the degradation typically ranges between 50% and 100%, with most cases falling in the moderate-to-severe degradation domain. At the same time, larger diameters and thicker tubes generally lead to an increase in dissipated energy, while longer members tend to show lower energy dissipation but also reduced degradation. The study therefore provides a reproducible computational framework and comparative performance trends for the assessment of low-cycle cyclic response in CFT beams under a prescribed loading protocol.

Journal of Composites Science doi: 10.3390/jcs10050235

Authors: Tabrej Khan Rahul Chamola Harri Junaedi Tamer A. Sebaey

Metal–polymer hybrid composites blend the high strength and stiffness of metals with the low weight and corrosion resistance of polymers. This synergy is expected to provide better crashworthiness, energy absorption, and design flexibility compared to traditional single-material structures. The present research intended to examine the crashworthiness features of an aluminium/CFRP structure under various operating conditions by optimizing process parameters through Design Expert software and experimental investigation. The design of the experiment was carried out using Design Expert software version 13 with response surface methodology (RSM) where working temperature, isothermal holding time, and crushing speed are taken as process variables. The test results demonstrate that the peak load, energy absorption (EA), and specific energy absorption (SEA) are significantly higher for the sample with working temperature, isothermal holding time, and crushing speed set at 25 °C, 13 h, and 5 mm/min, respectively. Moreover, EA and SEA are also relatively higher for this sample compared to the other samples. The test results showcased that temperature is a decisive factor for the mechanical properties of the tube, which is clearly reflected in experimental results. The higher peak force and EA indicate greater strength and a more energy-dissipative system. Moreover, a close correlation was observed between the experimentally measured and RSM-based optimization. Hence, RSM was found to be suitable for designing the experiments and for understanding the failure modes of the CFRP/aluminium structure.

Journal of Composites Science doi: 10.3390/jcs10050234

Authors: Zefeng Xu Shi Liu Qicai Ren Yi Yang Tao Tao Xinran Guo Yitong Zhou Jiaqiao Liang Peiyu Liu

This study proposes a novel pneumatically driven mechanically prestressed rhombic bistable composite laminate with asymmetric cylindrical curvature, which exhibits two weakly-coupled cylindrical shapes where each shape is influenced by planform and geometry parameters. A reduced-order analytical model is developed to predict the laminate’s quasi-static equilibrium shapes and snap-through transitions of the laminate under pneumatic work loading, which is triggered by the internal pressure applied to the fluidic channels. A sensitivity study based on the model investigates the influence of key planform and geometric parameters (the internal angle α and aspect ratio E) on the laminate’s out-of-plane deflection and snap-through pressure. The results show that increasing α reduces the critical prestrain required to achieve bistability and amplifies the out-of-plane deflection, while excessive α may lead to monostable curvature. Variations in aspect ratio modify the coupling stiffness between orthogonal PEMC layers, thereby influencing the bistable domain and critical snap-through pressure. These findings provide methods for the design of bistable composite structures.

Journal of Composites Science doi: 10.3390/jcs10050233

Authors: Liangdi Wang Yingjie Xu Jun Wang Shengnan Zhang

While carbon fiber-reinforced polymer (CFRP) composites are widely utilized in aerospace applications due to their exceptional specific strength and stiffness, they are inevitably subjected to impact loads during service, which can easily induce internal damage such as delamination. To mitigate these issues, this study investigates the low-velocity impact behavior of an SMA-reinforced CFRP U-shaped structure, emphasizing the critical role of curing-induced residual stresses. A numerical model incorporating the thermal-mechanical manufacturing history was developed and validated against experimental data. Results indicate that while embedded superelastic SMA wires effectively suppress crack propagation and enhance energy absorption, neglecting residual stresses leads to a significant overestimation of structural rigidity and peak loads. Due to the coefficient of thermal expansion mismatch between the SMA wires and the resin matrix, the SMA-CFRP system exhibits higher sensitivity to initial internal stresses than pure CFRP. By accounting for the residual stress field, the relative error in predicted peak force and absorbed energy for the SMA-CFRP model was reduced from 9.3% to 3.5% and 18.9% to 7.8%, respectively. These findings demonstrate that residual stress lowers the failure threshold and is essential for capturing the synergistic effects of SMA phase transformation and matrix damage, providing a more accurate reconstruction of the structural energy balance.

Journal of Composites Science doi: 10.3390/jcs10050232

Authors: A. Nogai A. Nogai E. Nogai N. Zikrillaev D. Uskenbaev A. Utegulov K. Muhamedrahimov

The article investigates the dielectric and conductive properties of the polar α-phase of Na3Fe2(PO4)3 polycrystals synthesized by solid-phase (sample type 1), melt (type 2), and melt-quenching (type 3) methods. To enable a rapid assessment of the dielectric properties of the polar α-phase of Na3Fe2(PO4)3, the thermo-polarization mobility parameter μTp(T, E(ω)) was introduced. By studying the dielectric properties, it was concluded that the polar α-phase of type 1 samples consists of large and small dipoles and ordered sodium cations, which possess low values of μTp(T, E(ω)), indicating the presence of strong interaction forces between the crystal lattice and the cationic part of the polycrystal. Additional studies of the samples’ conductivity confirm this conclusion. Studies of the polar α-phase of Na3Fe2(PO4)3 in type 2 samples have established that their structure contains dipoles and sodium cations with higher values of μTr(T, E(ω)), and also exhibits higher conductivity than Type 1 samples. These data indicate a weakening of the interaction forces between the cationic and anionic components in type 2 polycrystals due to a partial increase in crystal symmetry. The results of studies of the polar α-phase of type 3 samples show that their structure contains dipoles and sodium cations with higher values of μTr(T, E(ω)), and also exhibits higher conductivity than type 2 samples. It is concluded that the structure of type 3 samples is characterized by weak interaction forces between the cationic and anionic parts as a result of an increase in the symmetry of the polar α-phase of Na3Fe2(PO4)3, caused by sharply graded temperature conditions during the synthesis of polycrystals. By studying the dielectric properties of cathode materials, it is possible to obtain information on the extent of interactions between the cationic and anionic components in polycrystals. It is, therefore, appropriate to use this approach when investigating a wide range of new dielectric and ion-conducting materials.

Journal of Composites Science doi: 10.3390/jcs10050231

Authors: Elmas Rakıcı Güldal Sinan Melih Nigdeli Gebrail Bekdaş Zong Woo Geem

This study proposes a parameter-free metaheuristic optimization framework using the Jaya and Rao algorithms for the cost-based design of reinforced concrete (RC) frames in accordance with ACI 318-25. Beam and column dimensions are treated as design variables within predefined bounds, and the objective was to minimize the total construction cost including concrete and reinforcing steel. Structural analysis was performed using the matrix displacement method. The performance of the Jaya, Rao-1, Rao-2, and Rao-3 algorithms was evaluated through multiple independent runs. All methods achieved optimal or near-optimal solutions; however, Rao-2 demonstrated competitive performance with low mean values and favorable statistical performance. The results confirm the effectiveness of parameter-free metaheuristic methods for RC structural cost optimization. Unlike previous studies, this study explicitly focuses on parameter-free metaheuristic algorithms and evaluates their robustness through statistical analysis on reinforced concrete frame systems. The main contribution lies in demonstrating the comparative performance and practical applicability of parameter-free algorithms without the need for algorithm-specific parameter tuning.

Journal of Composites Science doi: 10.3390/jcs10050230

Authors: Md. Mominur Rahman Al Emran Ismail Muhammad Faiz Ramli Azrin Hani Abdul Rashid Tabrej Khan Omar Shabbir Ahmed Tamer A. Sebaey

The need to create lightweight materials with better mechanical properties has led to the use of Fiber Reinforced Composites (FRCs)s in the aerospace and automotive industries. The mechanical behavior of FRCs is heterogeneous, especially in conditions of low-velocity impact (LVI). The impact events cause structural damage, where most of the available literature deals with mono- or bi-composites in controlled situations. This work will present the results of studying the behavior of mono, bi- and tri-hybrids with carbon, glass and Kevlar fiber-reinforced epoxy. The sequences of the laminate stacks, number of plies and laminate thickness in the drop weight testing were across velocities of 1.91 to 3.91 m/s at drop heights of 19 to 79 cm. The dominant pillars of LVI, such as peak load, energy absorption and the modes of damage, were analyzed. The glass-dominated laminates peaked at 5.67 kN, while the Kevlar-dominated laminates reached peak flow in ductile collapse with greater quantities of absorbed energy. The leaders in strength and energy were the hybrids of Kevlar–glass (KG) cross-ply at 8.08 kN and 47.28 J and quasi-isotropic Kevlar–carbon–glass (KCG) at 9.12 kN and 47.25 J, showcasing a balance of strength and toughness. The rest, holding a greater quantity of Kevlar, ranging in thickness and cross-plies, were shaped with a load center. The experimental conclusion is that hybridization improved impact resistance and ductility, which is best supported by the glass/carbon rigidity-layered laminates. Such understanding directs the design work of future composite materials for better impact control.

Journal of Composites Science doi: 10.3390/jcs10050229

Authors: Raja Subramani

Functionally graded multi-material thermoplastic architectures provide a promising route for tailoring viscoelastic energy dissipation through controlled phase contrast and interfacial interactions. However, rational selection of optimal material compositions remains challenging due to competing requirements among stiffness, damping efficiency, thermal stability, and processability. The absence of a quantitative decision framework often limits systematic design of architected polymer systems. This study proposes an Analytic Hierarchy Process (AHP)-based multi-criteria decision model to identify the optimal rigid–elastic thermoplastic composition for enhanced damping performance. Nine performance criteria were considered, including storage modulus, loss factor, damping bandwidth, interfacial adhesion strength, elongation at break, impact resistance, glass transition temperature, thermal stability, and printability. Fourteen alternative material configurations combining different rigid phases, elastomeric interlayers, filler contents, and layer thickness ratios were evaluated. Pairwise comparison matrices were constructed based on experimentally measured thermomechanical data and literature-reported values, and consistency ratios were maintained below 0.1 to ensure decision reliability. Numerical results indicate that a graded PLA/soft-TPU/PLA architecture with optimized layer thickness ratio achieved the highest global priority weight (0.431), outperforming the baseline PLA/TPU system by approximately ~25–30% in overall performance index. Sensitivity analysis confirmed ranking robustness across variations in damping and stiffness weighting factors. The proposed framework establishes a systematic methodology for polymer material selection and multi-material architectural optimization, enabling data-driven design of thermoplastic systems with tunable viscoelastic performance.

Journal of Composites Science doi: 10.3390/jcs10050228

Authors: Vikas Yadav Akshay Dvivedi Subrata Chandra Das

Agricultural residues and agro-waste are increasingly recognized as valuable reinforcements for sustainable composite materials. Natural fibers derived from these biomasses offer biodegradability, low density, renewability, and potential environmental benefits. However, their performance and sustainability depend strongly on extraction, surface treatment, and processing conditions. Therefore, evaluating the environmental emissions associated with natural fiber biocomposites is essential before claiming sustainability advantages. In this research, flax, jute, kenaf, and bagasse fibers were extracted and treated using an eco-friendly sodium bicarbonate solution, then incorporated into polylactic acid (PLA) matrix to fabricate biocomposites via injection molding. A life cycle assessment (LCA) was conducted using the ReCiPe midpoint (H) method, with a functional unit defined as “per kg” of manufactured biocomposite. The results revealed that jute fiber composites generated the highest emissions across several impact categories, including climate change (1.290 × 101 kg CO2-Eq), terrestrial ecotoxicity (6.327 × 101 kg 1,4-DCB-Eq), human toxicity: carcinogenic effects (1.923 kg 1,4-DCB-Eq), and fossil resource use (3.202 kg oil-Eq). Jute also showed a 3.6% increase in terrestrial ecotoxicity and a 19.5% increase in land compared to flax, although it exhibited a 6.5% lower impact related to bagasse. A ±20% electricity-consumption sensitivity analysis further highlighted the dependence of environmental impacts on processing energy demand.

Journal of Composites Science doi: 10.3390/jcs10050227

Authors: Ziyi Peng Vladislav O. Alexenko Alexey A. Bogdanov Dmitry G. Buslovich Shaowei Lu Sergey V. Panin

In this study, the structure and mechanical properties of composites fabricated by polyetherimide film and powder lamination of carbon fabrics, as well as their impregnation with a polyetherimide/N-methylpyrrolidone solution at different contents, were compared. At compression sintering pressure of 10 MPa, the most uniform structure with the minimum number of discontinuities was formed by film lamination at the maximum carbon fabric content of 70 wt.%. For powder lamination, some discontinuities were found in the composites, which may be caused by the low melt flow index of the polyetherimide powder. The composites fabricated by impregnation with the dissolved PEI possessed low mechanical properties, so the compression sintering pressure was reduced to 6 MPa. After that, an improved composite was characterized by both uniform structure and high mechanical properties (even above those at film lamination), confirming the effectiveness of this fabrication method.

Journal of Composites Science doi: 10.3390/jcs10050226

Authors: Salmabanu Luhar Ashraf Ashour Ismail Luhar

Despite being fundamental to modern infrastructure, the cement and concrete industry is a major contributor to global carbon emissions, necessitating urgent decarbonisation strategies to mitigate climate change and achieve net-zero targets by 2050. This review explores technological pathways and innovations essential for lowering carbon emissions, including low-carbon materials, energy-efficient processes, carbon capture, utilization and storage (CCUS), and advanced production technologies. It also highlights the importance of supportive policy frameworks, financial incentives, and international collaboration in accelerating the transition to a low-carbon industry. While challenges such as high initial costs, resistance to change, and knowledge gaps persist, these can be addressed through innovation, education, and robust financial mechanisms. Furthermore, circular economy principles, sustainable procurement practices, and continued research and development are emphasized as critical enablers of the industry’s transformation. The paper concludes with recommendations for future actions, highlighting the role of cross-sector cooperation, research funding, and knowledge sharing in achieving a sustainable and decarbonised cement and concrete sector that can “go green” for eco-constructions.

Journal of Composites Science doi: 10.3390/jcs10050225

Authors: Junyang Chen Zhouyi Li Ying Wang Yuwen Wang Jinhu Shi

This work reveals the interlaminar fracture behavior and failure modes of carbon nanotube (CNT) film toughening composite laminates under Mode I and Mode II fractures. Experiment results display that the Mode I fracture toughness increases to its maximum value when a 2-layer CNT film is added, then it decreases with the increase in CNT layers. However, the trend changes with the number of CNT layers under Mode II fracture, that is, the fracture toughness gradually increases with the increase in CNT layers. This result indicates that compared to a Mode II fracture, the toughening effect of multi-layer CNT under a Mode I fracture has not been effectively produced. A novel micro-mechanical model, based on a Voronoi diagram, is established to identify the failure mode within the CNT toughening region. It is shown that the crack propagation paths of the two kinds of fracture modes are different: cracks propagate along the CNT/resin interface for Mode I fracture, while propagating simultaneously at both the interface and resin for Mode II fracture. The change in failure mode of the CNT toughening region is the reason for the various effects under the two-fracture loading. This work innovatively utilizes finite element simulation and cross-sectional micro characterization methods to reveal the differences in interlayer failure modes of CNT film interlayer toughening materials under different fracture modes, aiming to provide guidance for the application of CNT films in the field of interlayer toughening.

Journal of Composites Science doi: 10.3390/jcs10050223

Authors: Oana Maria Caramidaru Celina Maria Damian Gianina Popescu-Pelin Mihaela Bacalum Roberta Moisa Cornelia-Ioana Ilie Sorin-Ion Jinga Cristina Busuioc

Bone tissue plays a vital role in the human body and possesses intrinsic self-repair mechanisms; however, large defects or pathological fractures may exceed its natural healing capacity. Bone tissue engineering provides promising strategies to restore bone integrity through the use of scaffolds, growth factors, and stem cells. While calcium phosphate (CaP)-based ceramics, such as hydroxyapatite (HAp) and tricalcium phosphate (TCP), represent the current benchmark, their limitations, including slow degradation (HAp) and limited osteoinductivity (TCP), have driven the development of alternative biomaterials. In this context, magnesium phosphate (MgP)-based materials have gained increasing attention due to their tunable resorption rate, improved biodegradability, and ability to stimulate osteogenesis and angiogenesis through the release of magnesium (Mg2+) ions. This study reports on composite scaffolds based on electrospun poly(ε-caprolactone) (PCL) fibres coated with MgP layers doped with lithium (Li) and zinc (Zn), designed to mimic the nanofibrous architecture of the extracellular matrix. Lithium and zinc were selected due to their known ability to modulate cellular response, with lithium promoting osteogenic activity and zinc contributing to improved cell proliferation and antibacterial potential. The phosphate phases obtained by coprecipitation were deposited onto the PCL fibres using Matrix-Assisted Pulsed Laser Evaporation (MAPLE), enabling controlled surface functionalization. Following thermal treatment, the formation of the crystalline magnesium pyrophosphate (Mg2P2O7) phase was confirmed by chemical and structural characterization. The combination of a slowly degrading PCL matrix, providing sustained structural support, and a bioactive MgP coating, enabling rapid and controlled ion release, results in improved scaffold performance in terms of biocompatibility, biodegradability, and bioactivity. While the slow degradation rate of PCL ensures mechanical stability over an extended period, the surface-deposited MgP phase allows immediate interaction with the biological environment, facilitating faster ion release and enhancing cell–material interactions. These findings highlight the potential of the developed composites as promising candidates for trabecular bone regeneration and as viable alternatives to conventional CaP-based scaffolds in regenerative medicine.