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J. Compos. Sci., Volume 8, Issue 11 (November 2024) – 47 articles

Cover Story (view full-size image): This study investigates CF/PA6 thermoplastic composites and their mechanical performance with and without the use of micro-sized core–shell particles (CSPs) dispersed at the ply interfaces using a sieve. The mechanical test results showed that dispersing 4 wt% CSPs significantly improved the flexural strength (58.99%), interply shear strength (41.56%), and compressive strength (47.83%). The flexural stress–strain curves indicated delayed crack propagation, thereby enhancing mechanical performance. Post-failure micrographs revealed improved interaction between PA6 and CSPs at the ply interfaces. These findings highlight the potential of CSPs to strengthen ply interfaces in thermoplastic composites and enhance their interfacial characteristics. View this paper
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26 pages, 8526 KiB  
Article
Eco-Friendly Wall Cladding Panels from Recycled Fishing Gear and Clamshell Waste
by Zakariae Belmokhtar, Patrice Cousin, Saïd Elkoun and Mathieu Robert
J. Compos. Sci. 2024, 8(11), 484; https://doi.org/10.3390/jcs8110484 - 20 Nov 2024
Viewed by 425
Abstract
Eco-friendly wall cladding panels were developed from fishing industry waste by incorporating discarded ropes, wood fibers from lobster cages, and clamshell powder. Four panel formulations were investigated using MAPP and MAPE coupling agents: FRW-M (97% fishing rope), 30WF-M (67% rope with 30% wood [...] Read more.
Eco-friendly wall cladding panels were developed from fishing industry waste by incorporating discarded ropes, wood fibers from lobster cages, and clamshell powder. Four panel formulations were investigated using MAPP and MAPE coupling agents: FRW-M (97% fishing rope), 30WF-M (67% rope with 30% wood fibers), 30CS-M (67% rope with 30% clamshell powder), and a hybrid 15CS15WF-M (67% rope with 15% each of wood fibers and clamshell powder). A DSC analysis revealed that clamshell powder addition reduced melting temperatures and crystallinity, while wood fiber incorporation led to slight increases in melting temperatures. The hybrid formulation exhibited enhanced crystallization temperatures despite lower overall crystallinity. A dynamic mechanical analysis showed an 85% improvement in storage modulus for the hybrid panel, with flexural testing demonstrating a 202% increase in modulus and 20% increase in strength. SEM-EDS analysis confirmed improved filler dispersion and interfacial adhesion in the hybrid formulation. Water absorption was lowest in FRW-M and highest in 30WF-M, while burning rate tests showed 30CS-M and 30WF-M as the best and worst performers, respectively. The hybrid formulation emerged as the optimal solution, combining enhanced mechanical properties with improved water resistance and fire retardancy, presenting a viable sustainable alternative for wall cladding applications. Full article
(This article belongs to the Section Biocomposites)
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13 pages, 1589 KiB  
Article
The Influence of Activated Carbon Particle Size on the Properties and Performance of Polysulfone Composite Membrane for Protein Separation
by Gunawan Setia Prihandana, Aisyah Dewi Muthi’ah, Tutik Sriani and Muslim Mahardika
J. Compos. Sci. 2024, 8(11), 483; https://doi.org/10.3390/jcs8110483 - 19 Nov 2024
Viewed by 517
Abstract
The superiorities provided by polymeric composite membranes in comparison to the original membrane have generated increased attention, particularly in the field of protein separation applications. This work involved the fabrication of polysulfone composite membranes using variable loadings of activated carbon particle sizes, namely, [...] Read more.
The superiorities provided by polymeric composite membranes in comparison to the original membrane have generated increased attention, particularly in the field of protein separation applications. This work involved the fabrication of polysulfone composite membranes using variable loadings of activated carbon particle sizes, namely, 37 µm, 74 µm, 149 µm, and 297 µm. The membranes were fabricated via the phase-inversion method, employing water as the coagulant. In this study, the impact of the AC powder particle sizes on membrane morphology, water contact angle, porosity, average pore size, molecular weight cutoff, pure water flux, and protein rejection was examined. Different membrane morphologies and properties were achieved by incorporating a variety of AC particle sizes. A porous membrane with the maximum pure water flux was generated by the loading of finer AC particles. Concurrently, protein rejection is increasing as a result of the use of AC particles as an infill in the composite membrane. In comparison to all fabricated membranes, the AC filler with a particle size of 149 µm exhibited the highest rejection of the lysozyme protein, reaching up to 73.9%, with a relatively high water permeability of 33 LMH/Bar. In conclusion, this investigation provides recommendations for the selection of AC particle sizes for protein separation in conjunction with PSF ultrafiltration membranes. Full article
(This article belongs to the Topic Advanced Composites Manufacturing and Plastics Processing)
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10 pages, 2756 KiB  
Article
Utilizing Pistachio Shell Biochar to Replace Carbon Black in Natural Rubber Composites
by Steven C. Peterson and Bret J. Chisholm
J. Compos. Sci. 2024, 8(11), 482; https://doi.org/10.3390/jcs8110482 - 19 Nov 2024
Viewed by 429
Abstract
Biochar is a promising source of renewable carbon that potentially can serve the same purpose as carbon black (sourced from fossil fuels) to reinforce rubber composites. Pistachio shells are a prolific agricultural waste product that is a suitable feedstock for biochar. Unlike many [...] Read more.
Biochar is a promising source of renewable carbon that potentially can serve the same purpose as carbon black (sourced from fossil fuels) to reinforce rubber composites. Pistachio shells are a prolific agricultural waste product that is a suitable feedstock for biochar. Unlike many other agricultural residues, pistachio shells are a feedstock that yields biochar with a high concentration of carbon (>80%) and low concentration of ash (<5%), which is necessary to replace carbon black without detrimental effects to the final composite. Filler blends of pistachio shell biochar and carbon black were explored to see how much carbon black could be replaced before composite properties were affected. Pistachio shell biochar was able to replace up to 40% of the carbon black while improving the tensile strength, elongation, and toughness of the rubber composites, but a reduction in modulus was observed. Based on the results obtained, pistachio shell biochar would be suitable for partially replacing carbon black in applications like hoses, seals, belts, and gloves, thereby enabling a new application for this sustainable, agricultural waste product that will help reduce dependence on fossil fuels. Full article
(This article belongs to the Special Issue Composites: A Sustainable Material Solution)
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20 pages, 3334 KiB  
Review
Recent Development of Graphene-Based Composites for Electronics, Energy Storage, and Biomedical Applications: A Review
by Felipe J. Elizalde-Herrera, Pablo A. Flores-Soto, Luis F. Mora-Cortes, Francisco J. González, Gustavo Soria-Arguello, Felipe Avalos-Belmontes, Rosa I. Narro-Céspedes and Mario Hoyos
J. Compos. Sci. 2024, 8(11), 481; https://doi.org/10.3390/jcs8110481 - 19 Nov 2024
Viewed by 553
Abstract
Nanomaterials are attractive materials for researchers because they have essential characteristics in terms of their properties. Carbon has an ample range of crystalline allotropes. Some, such as graphite and diamond, have been known since ancient times, while new forms of carbon with potential [...] Read more.
Nanomaterials are attractive materials for researchers because they have essential characteristics in terms of their properties. Carbon has an ample range of crystalline allotropes. Some, such as graphite and diamond, have been known since ancient times, while new forms of carbon with potential for various applications have been discovered in recent decades. Since the discovery of graphene 20 years ago, research has increased on composite materials that take advantage of carbon structures for their electrical, thermal, and mechanical properties and their ability to be synthesized at the nanometer scale. Graphene has stood out above other nanomaterials due to its surprising properties and high impact on technological research, so its uses have diversified in different areas of science such as medicine, electronics, engineering, etc. This work aims to show some new and innovative applications of graphene, on which we can see its versatility as engineering material. It also seeks to show its potential in research and development processes for its use. These are key components of advanced graphene-based materials systems under active development, with an eye on the future of advanced materials science and technology. Full article
(This article belongs to the Section Carbon Composites)
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14 pages, 11409 KiB  
Article
Mesoscopic Simulation on Centrifugal Melt Electrospinning of Polyetherimide and Polyarylethernitrile
by Han Guo, Yuzhe Huang, Jia Chen, Hongyu Huo, Gongqiu Peng, Baoyan Zhang and Yong Liu
J. Compos. Sci. 2024, 8(11), 480; https://doi.org/10.3390/jcs8110480 - 19 Nov 2024
Viewed by 441
Abstract
Polyetherimide (PEI) and polyarylethernitrile (PEN) are high–performance materials for various applications. By optimizing their fiber morphology, their performance can be further enhanced, leading to an expanded range of applications in carbon fiber composites. However, developing processes for stable and efficient fiber production remains [...] Read more.
Polyetherimide (PEI) and polyarylethernitrile (PEN) are high–performance materials for various applications. By optimizing their fiber morphology, their performance can be further enhanced, leading to an expanded range of applications in carbon fiber composites. However, developing processes for stable and efficient fiber production remains challenging. This research aims to simulate the preparation of high–performance ultrafine PEI or PEN fibers using electrospinning. A mesoscopic simulation model for centrifugal melt electrospinning was constructed to compare and analyze the changes in molecular chain orientation, unfolding, fiber diameter, and fiber yield under high-voltage electrostatic fields. The simulation results showed that temperature and electric field force had a particular impact on the diameter and yield of PEI and PEN fibers. Changes in rotational speed had negligible effects on both PEI and PEN fibers. Additionally, due to their different molecular structures, PEI and PEN, which have different chain lengths, exhibit varied spinning trends. This study established a mesoscopic dynamic foundation for producing high-performance ultrafine fibers and provided theoretical guidance for future electrospinning experiments. Full article
(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)
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21 pages, 18918 KiB  
Article
Structural and Sustainability Enhancement of Composite Sandwich Slab Panels Using Novel Fibre-Reinforced Geopolymer Concrete
by M. Sridhar and M. Vinod Kumar
J. Compos. Sci. 2024, 8(11), 479; https://doi.org/10.3390/jcs8110479 - 18 Nov 2024
Viewed by 427
Abstract
One of the important findings of the recent decades in the construction industry is composite sandwich panels (CSPs), which have benefits of being lightweight, providing thermal insulation, and aiding the economy; they are transforming continuously through many add-ons as needed by the industry. [...] Read more.
One of the important findings of the recent decades in the construction industry is composite sandwich panels (CSPs), which have benefits of being lightweight, providing thermal insulation, and aiding the economy; they are transforming continuously through many add-ons as needed by the industry. With the demand for sustainability in the field, CSPs need structural and sustainable enhancement. In the present study, an approach for the same has been attempted with geopolymer concrete (GPC) and novel nylon fibre to improve the sustainability and structural benefits, respectively. With various material combinations including GPC reinforced with fibres, six CSPs were cast and studied. The inherent limitations of GPC have been addressed by the nylon fibre reinforcement instead of using steel fibres, which have a similar strength, considering the aim of maintaining the density of the wythe material. A comparison of the flexural behaviour of the CSPs through the parameters of load–deflection, ductility, and toughness was made using the four-point loading test. The results of the test specify that the fibres enhance the performance of the CSPs under flexural loading. Full article
(This article belongs to the Section Composites Applications)
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13 pages, 7087 KiB  
Article
Numerical Analysis on Static Performances of Graphene Platelet-Reinforced Ethylene-Tetrafluoroethylene (ETFE) Composite Membrane Under Wind Loading
by Yu Wang, Jiajun Gu, Xin Zhang, Jian Fan, Wenbin Ji and Chuang Feng
J. Compos. Sci. 2024, 8(11), 478; https://doi.org/10.3390/jcs8110478 - 18 Nov 2024
Viewed by 311
Abstract
This study examines the static performances of a graphene platelet (GPL)-reinforced ethylene tetrafluoroethylene (ETFE) composite membrane under wind loadings. The wind pressure distribution on a periodic tensile membrane unit was analyzed by using CFD simulations, which considered various wind velocities and directions. A [...] Read more.
This study examines the static performances of a graphene platelet (GPL)-reinforced ethylene tetrafluoroethylene (ETFE) composite membrane under wind loadings. The wind pressure distribution on a periodic tensile membrane unit was analyzed by using CFD simulations, which considered various wind velocities and directions. A one-way fluid–structure interaction (FSI) analysis incorporating geometric nonlinearity was performed in ANSYS to evaluate the static performances of the composite membrane. The novelty of this research lies in the integration of graphene platelets (GPLs) into ETFE membranes to enhance their static performance under wind loading and the combination of micromechanical modelling for obtaining material properties of the composites and finite element simulation for examining structural behaviors, which is not commonly explored in the existing literature. The elastic properties required for the structural analysis were determined using effective medium theory (EMT), while Poisson’s ratio and mass density were evaluated using rule of mixtures. Parametric studies were carried out to explore the effects of a number of influencing factors, including pre-strain, attributes of wind, and GPL reinforcement. It is demonstrated that higher initial strain effectively reduced deformation under wind loads at the cost of increased stress level. The deformation and stress significantly increased with the increase in wind velocity. The deflection and stress level vary with the wind direction, and the maximum values were observed when the wind comes at 15° and 45°, respectively. Introducing GPLs with a larger surface area into membrane material has proven to be an effective way to control membrane deformation, though it also results in a higher stress level, indicating a trade-off between deformation management and stress management. Full article
(This article belongs to the Special Issue Theoretical and Computational Investigation on Composite Materials)
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40 pages, 1269 KiB  
Review
Fatigue Failure of Adhesive Joints in Fiber-Reinforced Composite Material Under Step/Variable Amplitude Loading—A Critical Literature Review
by Abinash Patro and Ala Tabiei
J. Compos. Sci. 2024, 8(11), 477; https://doi.org/10.3390/jcs8110477 - 18 Nov 2024
Viewed by 389
Abstract
Most fatigue-loading research has concentrated on constant-amplitude tests, which seldom represent actual service conditions. Because of the significant time and expense associated with variable-amplitude experiments, researchers often employ block/step-loading tests to evaluate the effects of variable-amplitude loading. These tests utilize various sequences of [...] Read more.
Most fatigue-loading research has concentrated on constant-amplitude tests, which seldom represent actual service conditions. Because of the significant time and expense associated with variable-amplitude experiments, researchers often employ block/step-loading tests to evaluate the effects of variable-amplitude loading. These tests utilize various sequences of low-to-high and high-to-low loads to simulate real-world scenarios. Empirical investigations have shown inconsistencies in the damage accumulation under different load sequences. Although literature reviews exist for simulation and experimental methods, there is limited research examining the impact of step/variable-amplitude loading on adhesive joints in composite materials. This review aims to address this gap by comprehensively analyzing the effects of load sequence and block loading on fatigue damage progression in fiber-reinforced polymer composites. Additionally, the applicability of various step-loading fatigue damage accumulation models to adhesive materials is evaluated through numerical simulation to study its suitability in predicting fatigue failure. This review also explores recent theoretical advancements in this field over the past few years, examining more than 100 fatigue damage accumulation models categorized into seven subcategories: (i) linear damage rules, (ii) nonlinear damage curve and two-stage linearization models, (iii) life curve modification models, (iv) models based on crack growth concepts, (v) continuum damage mechanics-based models, (vi) material degradation models, and (vii) energy-based models. Finally, numerical simulations using the most common nonlinear cumulative fatigue damage accumulation models were conducted to predict fatigue failure in adhesively bonded joints under four step-loading tests, and the results were compared with the experimental data. Numerical simulations revealed the need and scope of further development of a fatigue failure model under step/variable loading. This comprehensive review offers valuable insights into the complex nature of fatigue failure in adhesive joints under variable loading conditions and highlights current state-of-the-art nonlinear fatigue damage accumulation models for adhesive materials. Full article
(This article belongs to the Section Fiber Composites)
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26 pages, 13491 KiB  
Article
Comparative Study on the Impact of Various Non-Metallic Fibres on High-Performance Concrete Properties
by Aleksandrs Korjakins, Girts Kolendo, Vitalijs Lusis, Laura Spure, Kaspars Bondars, Diana Bajare and Genadijs Sahmenko
J. Compos. Sci. 2024, 8(11), 476; https://doi.org/10.3390/jcs8110476 - 17 Nov 2024
Viewed by 493
Abstract
The performance of high-performance concrete has been enhanced in the present study by incorporating non-metallic fibres without altering the binder content. The impact of these fibres on high-performance concrete flexural and compression characteristics and the arrangement of fibres within the composite were systematically [...] Read more.
The performance of high-performance concrete has been enhanced in the present study by incorporating non-metallic fibres without altering the binder content. The impact of these fibres on high-performance concrete flexural and compression characteristics and the arrangement of fibres within the composite were systematically analysed. Unlike conventional practices, the authors of the research introduce various non-metallic fibres, including alkali-resistant glass fibres, carbon microfibers, three types of polypropylene microfibers, and one type of polyvinyl alcohol fibre while maintaining an equal amount of binder. The research aims to comprehensively evaluate the fibre’s influence on cement composite properties. Various types of non-metallic fibres, highlighting differences in diameters and their physical-mechanical properties with a constant amount by volume, have been considered in the research. Alkali-resistant glass and carbon fibres exhibit low values of residual post-cracking force but polyvinyl alcohol fibres demonstrate the best post-cracking behaviour, with a residual post-cracking force value. This detailed examination of fibre distribution and composition sheds light on the nuanced effects on fresh and hardened concrete properties. Notably, this work diverges from existing research by maintaining a constant binder amount and considering the quantitative distribution of fibres in a unit volume of the cement matrix, along with their aspect ratio. These findings provide valuable insights for selecting the most suitable non-metallic fibres for enhancing high-performance concrete properties. Full article
(This article belongs to the Special Issue Novel Cement and Concrete Materials)
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20 pages, 8020 KiB  
Article
Green Synthesis of Nanoparticle-Loaded Bacterial Cellulose Membranes with Antibacterial Properties
by Mohammed Khikani, Gabriela-Olimpia Isopencu, Iuliana-Mihaela Deleanu, Sorin-Ion Jinga and Cristina Busuioc
J. Compos. Sci. 2024, 8(11), 475; https://doi.org/10.3390/jcs8110475 - 16 Nov 2024
Viewed by 414
Abstract
The current work proposes the development of composite membranes based on bacterial cellulose (BC) loaded with silver (Ag) and zinc oxide (ZnO) nanostructures by in situ impregnation. The research involves the production and purification of BC, followed by its loading with different types [...] Read more.
The current work proposes the development of composite membranes based on bacterial cellulose (BC) loaded with silver (Ag) and zinc oxide (ZnO) nanostructures by in situ impregnation. The research involves the production and purification of BC, followed by its loading with different types of phases with the help of different precipitating solutions, turmeric extract (green synthesis) and ammonia (classic route). Additionally, the combination of both antibacterial agents into a single BC matrix to valorise the benefits of each, proposing a novel BC-Ag-ZnO composite with distinct characteristics, was explored. Overall, the synthesis was marked by colour changes from the light beige of the BC membrane to dark brown, dark orange and dark green for BC-Ag, BC-ZnO and BC-Ag-ZnO samples, which is proof of successful composites formation. The results proved that the antibacterial phases are attached as nanoparticles or nanosheets on BC fibres, with Ag being in a crystalline state, while ZnO showed a rather amorphous structure. Regarding the antibacterial efficiency, the BC-ZnO composite obtained by employing two precipitating solutions turned out to be the best material against both tested Gram-negative and Gram-positive bacterial strains. Full article
(This article belongs to the Section Biocomposites)
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22 pages, 2607 KiB  
Review
Wood–Cement Composites: A Sustainable Approach for Mitigating Environmental Impact in Construction
by Dorin Maier, Daniela Lucia Manea, Daniela-Roxana Tămaș-Gavrea, Alexandra Țiriac and Paul Costin
J. Compos. Sci. 2024, 8(11), 474; https://doi.org/10.3390/jcs8110474 - 15 Nov 2024
Viewed by 563
Abstract
The construction industry’s environmental impact has become a growing concern, largely due to the energy-intensive production of conventional building materials. This paper explores the potential of wood–cement composites as a more sustainable alternative through a comprehensive literature review, including a bibliometric and scientometric [...] Read more.
The construction industry’s environmental impact has become a growing concern, largely due to the energy-intensive production of conventional building materials. This paper explores the potential of wood–cement composites as a more sustainable alternative through a comprehensive literature review, including a bibliometric and scientometric analysis of research trends. Our analysis traces the evolution of wood–cement composites from early studies focused on mechanical properties, to recent investigations into their environmental benefits and practical applications. Key findings suggest that optimal performance can be achieved by treating wood with tetraethyl orthosilicate, incorporating additives like cellulose nanocrystals or wollastonite, and using wood from species such as Pinus. While partial cement replacement with wood waste and ash offers significant environmental advantages, precise formulations are needed to maintain structural integrity. This study also acknowledges certain methodological limitations, such as the reliance on keyword-based filtering, which may have excluded some relevant studies. Future research should address long-term durability, economic feasibility, and standardized testing methodologies to facilitate the adoption of wood–cement composites in the construction industry. These materials, particularly suitable for non-structural applications and insulation, hold promise as viable, eco-friendly building solutions capable of reducing the construction industry’s carbon footprint. Full article
(This article belongs to the Special Issue Behaviour and Analysis of Timber–Concrete Composite Structures)
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16 pages, 8585 KiB  
Article
Hemp Waste Stream Valorization Through Pyrolytic Carbonization for Epoxy Composite Strengthening
by Silvia Zecchi, Giovanni Cristoforo, Mattia Bartoli, Carlo Rosso and Alberto Tagliaferro
J. Compos. Sci. 2024, 8(11), 473; https://doi.org/10.3390/jcs8110473 - 14 Nov 2024
Viewed by 420
Abstract
This research addresses a gap in the literature by exploring the combined use of hemp and hemp hurds in composites, presenting a novel approach to bio-composite development. We report on the mechanical properties of epoxy resin composites reinforced with hemp fibers and hemp [...] Read more.
This research addresses a gap in the literature by exploring the combined use of hemp and hemp hurds in composites, presenting a novel approach to bio-composite development. We report on the mechanical properties of epoxy resin composites reinforced with hemp fibers and hemp hurds, selected for their sustainability, biodegradability, and environmental benefits. These natural fibers offer a renewable alternative to synthetic fibers, aligning with the growing demand for eco-friendly materials in various industries. The primary objective was to evaluate how different filler contents and hemp hurd-to-hemp fiber ratios affect the composite’s performance. Composites with 1:1 and 3:1 ratios were prepared at filler concentrations ranging from 1 wt.% to 10 wt.%. Tensile tests revealed that the 3:1 ratio composites exhibited better stiffness and tensile strength, with a notable UTS of 19.8 ± 0.4 MPa at 10 wt.%, which represents a 160% increase over neat epoxy. The 1:1 ratio composites showed significant reductions in mechanical properties at higher filler contents due to filler agglomeration. The study concludes that a 3:1 hemp hurd-to-hemp fiber ratio optimizes mechanical properties, offering a sustainable solution for enhancing composite materials’ performance in industrial applications. Full article
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25 pages, 11646 KiB  
Article
Finite Element Modelling of Circular Concrete-Filled Steel Tubular Columns Under Quasi-Static Axial Compression Loading
by Ghassan Almasabha and Mohammad Ramadan
J. Compos. Sci. 2024, 8(11), 472; https://doi.org/10.3390/jcs8110472 - 13 Nov 2024
Viewed by 700
Abstract
This paper presents a modified finite element analysis (FEA) model for predicting the axial compression strength of large-diameter concrete-filled steel tubular (CFST) stub columns, addressing the gap in research that has often focused on smaller diameters. The size effect, which significantly impacts the [...] Read more.
This paper presents a modified finite element analysis (FEA) model for predicting the axial compression strength of large-diameter concrete-filled steel tubular (CFST) stub columns, addressing the gap in research that has often focused on smaller diameters. The size effect, which significantly impacts the structural performance of large-diameter CFST columns, is a key focus of this study. The goal is to validate the accuracy and reliability of the modified FEA model by comparing its predictions with experimental data from the literature, specifically examining ultimate axial load capacity, failure modes, and deformed shapes. In addition to validating the model, this study includes a comprehensive parametric analysis that explores how critical geometric parameters such as the diameter-to-thickness (D/t) ratio and length-to-diameter (L/D) ratio affect the axial compressive behavior of CFST stub columns. By systematically varying these parameters, the research provides valuable insights into the load-bearing capacity, deformation characteristics, and failure mechanisms of CFST columns. Furthermore, the material properties of the steel tube—particularly its yield strength—and the compressive strength of the concrete core are investigated to optimize the design and safety performance of these columns. The results indicate that the FEA model shows excellent agreement with experimental results, accurately predicting the axial load-strain response. It was observed that as the diameter of the steel tube increases, the peak stress, peak strain, strength index, and ductility index tend to decrease, underscoring the size effect. Conversely, an increase in the yield strength and thickness of the steel tube enhances the ultimate strength of the CFST columns. These findings demonstrate the reliability of the modified FEA model in predicting the behavior of large-diameter CFST columns, offering a useful tool for optimizing designs and improving safety margins in structural applications. Full article
(This article belongs to the Section Composites Modelling and Characterization)
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14 pages, 2909 KiB  
Article
Laser-Induced Decomposition and Mechanical Degradation of Carbon Fiber-Reinforced Polymer Subjected to a High-Energy Laser with Continuous Wave Power up to 120 kW
by Sebastian Schäffer, Stefan Reich, Dominic Heunoske, Martin Lueck, Johannes Wolfrum and Jens Osterholz
J. Compos. Sci. 2024, 8(11), 471; https://doi.org/10.3390/jcs8110471 - 13 Nov 2024
Viewed by 519
Abstract
Carbon fiber-reinforced polymer (CFRP), noted for its outstanding properties including high specific strength and superior fatigue resistance, is increasingly employed in aerospace and other demanding applications. This study investigates the interactions between CFRP composites and high-energy lasers (HEL), with continuous wave laser powers [...] Read more.
Carbon fiber-reinforced polymer (CFRP), noted for its outstanding properties including high specific strength and superior fatigue resistance, is increasingly employed in aerospace and other demanding applications. This study investigates the interactions between CFRP composites and high-energy lasers (HEL), with continuous wave laser powers reaching up to 120 kW. A novel automated sample exchange system, operated by a robotic arm, minimizes human exposure while enabling a sequence of targeted laser tests. High-speed imaging captures the rapid expansion of a plume consisting of hot gases and dust particles during the experiment. The research significantly advances empirical models by systematically examining the relationship between laser power, perforation times, and ablation rates. It demonstrates scalable predictions for the effects of high-energy laser radiation. A detailed examination of the damaged samples, both visually and via micro-focused computed X-ray tomography, offers insights into heat distribution and ablation dynamics, highlighting the anisotropic thermal properties of CFRP. Compression after impact (CAI) tests further assess the residual strength of the irradiated samples, enhancing the understanding of CFRP’s structural integrity post-irradiation. Collectively, these tests improve the knowledge of the thermal and mechanical behavior of CFRP under extreme irradiation conditions. The findings not only contribute to predictive modeling of CFRP’s response to laser irradiation but enhance the scalability of these models to higher laser powers, providing robust tools for predicting material behavior in high-performance settings. Full article
(This article belongs to the Special Issue Carbon Fiber Composites, Volume III)
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17 pages, 26255 KiB  
Article
The Influence of the Amount of Technological Waste on the Performance Properties of Fibrous Polymer Composites
by Jozef Dobránsky, Miroslav Gombár and Patrik Fejko
J. Compos. Sci. 2024, 8(11), 470; https://doi.org/10.3390/jcs8110470 - 13 Nov 2024
Viewed by 455
Abstract
The objective of the experimental analysis was to assess the impact of the reuse of technological waste (recyclate) on the selected performance properties of the fibrous polymer composite used to produce components for the automotive industry by injection molding technology. Polyphthalamide (PPA), which [...] Read more.
The objective of the experimental analysis was to assess the impact of the reuse of technological waste (recyclate) on the selected performance properties of the fibrous polymer composite used to produce components for the automotive industry by injection molding technology. Polyphthalamide (PPA), which belongs to a group of high-tech polymers, was chosen as the analyzed material. In accordance with the set goals, the rheological, mechanical, and structural properties of the material were evaluated using ANOVA analysis in the experimental part of the work, depending on the mass ratio of the recycled material added to the virgin material. The influence of the proportion of recycled material on the lifetime of moldings by the method of their exposure at an elevated temperature for a defined time was also assessed. During the research, it was found that at a concentration of up to 40 wt. % of recyclate, its mechanical properties do not change significantly. At a concentration of 50 wt. %, there is a rapid decrease in mechanical properties. In the long term, it can also be said that the addition of recyclate significantly affects the service life of the components. No significant changes in morphology were observed during the analysis of structural properties. Full article
(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)
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12 pages, 2155 KiB  
Article
Mullite Synthesis Using Porous 3D Structures Consisting of Nanofibrils of Aluminum Oxyhydroxide Chemically Modified with Ethoxysilanes
by Anatole Khodan, Thi Hang Nga Nguyen and Andrei Kanaev
J. Compos. Sci. 2024, 8(11), 469; https://doi.org/10.3390/jcs8110469 - 12 Nov 2024
Viewed by 644
Abstract
Nanocrystalline mullite was synthetized by annealing a highly porous 3D structure consisting of nanofibrous aluminum oxyhydroxides treated with ethoxysilanes. The chemical, structural, and phase transformations in the aluminosilicate nanosystem were studied in the temperature range between 100 and 1600 °C. The features of [...] Read more.
Nanocrystalline mullite was synthetized by annealing a highly porous 3D structure consisting of nanofibrous aluminum oxyhydroxides treated with ethoxysilanes. The chemical, structural, and phase transformations in the aluminosilicate nanosystem were studied in the temperature range between 100 and 1600 °C. The features of the solid-phase synthesis of mullite at the interface of crystalline alumina with a liquid silica layer are discussed. It was established that chemical modification of the alumina surface with ethoxysilanes significantly limits the interphase mass transport and delays the phase transformation of the amorphous oxide into γ-Al2O3, which begins at temperatures above 1000 °C, while the basic structural nanofibrils are already crystallized at ~850 °C. The formation of mullite was completed at temperatures ≥ 1200 °C, where the fraction of γ-Al2O3 sharply decreased. Full article
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28 pages, 13055 KiB  
Article
Structural Behavior of Full-Depth Deck Panels Having Developed Closure Strips Reinforced with GFRP Bars and Filled with UHPFRC
by Mahmoud Sayed Ahmed, Khaled Sennah and Hamdy M. Afefy
J. Compos. Sci. 2024, 8(11), 468; https://doi.org/10.3390/jcs8110468 - 12 Nov 2024
Viewed by 533
Abstract
The adoption of prefabricated elements and systems (PBES) in accelerating bridge construction (ABC) and rapidly replacing aging infrastructure has attracted considerable attention from bridge authorities. These prefabricated components facilitate quick assembly, which diminishes the environmental footprint at the construction site, alleviates delays and [...] Read more.
The adoption of prefabricated elements and systems (PBES) in accelerating bridge construction (ABC) and rapidly replacing aging infrastructure has attracted considerable attention from bridge authorities. These prefabricated components facilitate quick assembly, which diminishes the environmental footprint at the construction site, alleviates delays and lane closures, reduces disruption for the traveling public, and ultimately conserves both time and taxpayer resources. The current paper explores the structural behavior of a reinforced concrete (RC) precast full-depth deck panel (FDDP) having 175 mm projected glass-fiber-reinforced polymer (GFRP) bars embedded into a 200 mm wide closure strip filled with ultra-high-performance fiber-reinforced concrete (UHPFRC). Three joint details for moment-resisting connections (MRCs), named the angle joint, C-joint, and zigzag joint, were constructed and loaded to collapse. The controlled slabs and mid-span-connected precast FDDPs were statically loaded to collapse under concentric or eccentric wheel loading. The moment capacity of the controlled slab reinforced with GFRP bars compared with the concrete slab reinforced with steel reinforcing bars was less than 15% for the same reinforcement ratio. The precast FDDPs showed very similar results to those of the controlled slab reinforced with GFRP bars. The RC slab reinforced by steel reinforcing bars failed in the flexural mode, while the slab reinforced by GFRP bars failed in flexural-shear one. Full article
(This article belongs to the Special Issue Novel Cement and Concrete Materials)
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14 pages, 3225 KiB  
Article
Effects of Geometry and Supporting Silicone Layers on the Performance of Conductive Composite High-Deflection Strain Gauges
by Hailey E. Jones, Spencer A. Baker, Jadyn J. Christensen, Tyler Hutchinson, Heather A. Leany, Ulrike H. Mitchell, Anton E. Bowden and David T. Fullwood
J. Compos. Sci. 2024, 8(11), 467; https://doi.org/10.3390/jcs8110467 - 11 Nov 2024
Viewed by 745
Abstract
Piezoresistive sensors composed of nickel nanostrands, nickel-coated carbon fibers, and silicone can be used to measure large physical deflections but exhibit viscoelastic properties and creep, leading to a complex and nonlinear electrical response that is difficult to interpret. This study considers the impact [...] Read more.
Piezoresistive sensors composed of nickel nanostrands, nickel-coated carbon fibers, and silicone can be used to measure large physical deflections but exhibit viscoelastic properties and creep, leading to a complex and nonlinear electrical response that is difficult to interpret. This study considers the impact of modifying the geometry and architecture of the sensors on their mechanical and electrical performance. Varying the sensor thickness leads to potentially significant differences in conductive fiber alignment, while adding external layers of pure silicone provides elastic support for the sensors, potentially reducing their extreme viscoelastic nature. The impact of such modifications on both mechanical and electrical behavior was assessed by analyzing strain to failure, the magnitude of hysteresis with cycling, the repeatability of the electro-mechanical response, the strain level at which resistance begins to monotonically decrease, and the drift in electrical response with cycling. The results indicate that thicker single-layer sensors have less electrical drift. Sensors with a multilayered architecture exhibit several improvements in behavior, such as increasing the range of the monotonic region by approximately 52%. These improvements become more significant as the thickness of the pure silicone layers increases. Full article
(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2024)
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12 pages, 2455 KiB  
Article
Effect of Mechanically Exfoliated Graphite Flakes on Morphological, Mechanical, and Thermal Properties of Epoxy
by Ayşenur Gül and Ali Reza Kamali
J. Compos. Sci. 2024, 8(11), 466; https://doi.org/10.3390/jcs8110466 - 11 Nov 2024
Viewed by 730
Abstract
Carbon-reinforced polymer composites form an important category of advanced materials, and there is an increasing demand to enhance their performance using more convenient and scalable processes at low costs. In the present study, graphitic flakes were prepared by the mechanical exfoliation of synthetic [...] Read more.
Carbon-reinforced polymer composites form an important category of advanced materials, and there is an increasing demand to enhance their performance using more convenient and scalable processes at low costs. In the present study, graphitic flakes were prepared by the mechanical exfoliation of synthetic graphite electrodes and utilized as an abundant and potentially low-cost filler to fabricate epoxy-based composites with different additive ratios of 1–10 wt.%. The morphological, structural, thermal, and mechanical properties of these composites were investigated. It was found that the thermal conductivity of the composites increases by adding graphite, and this increase mainly depends on the ratio of the graphite additive. The addition of graphite was found to have a diverse effect on the mechanical properties of the composites: the tensile strength of the composites decreases with the addition of graphite, whilst their compressive strength and elastic modulus are enhanced. The results demonstrate that incorporating 5 wt% of commercially available graphite into epoxy not only raises the thermal conductivity of the material from 0.223 to 0.485 W/m·K, but also enhances its compressive strength from 66 MPa to 72 MPa. The diverse influence of graphite provides opportunities to prepare epoxy composites with desirable properties for different applications. Full article
(This article belongs to the Special Issue Mechanical Properties of Composite Materials and Joints)
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12 pages, 7441 KiB  
Article
Transforming Tree Bark Waste into a Green Composite: Mechanical Properties and Biodegradability
by Lovisa Rova, Juson Kokubo, Zhenjin Wang, Hiroki Kurita and Fumio Narita
J. Compos. Sci. 2024, 8(11), 465; https://doi.org/10.3390/jcs8110465 - 11 Nov 2024
Viewed by 668
Abstract
In this study, a “green composite” material made from 60% tree bark and 40% polylactic acid (PLA) was fabricated and evaluated according to its mechanical properties and biodegradability. Biodegradation tests were performed in compost, simulated aquatic environments, and natural soil. In compost, the [...] Read more.
In this study, a “green composite” material made from 60% tree bark and 40% polylactic acid (PLA) was fabricated and evaluated according to its mechanical properties and biodegradability. Biodegradation tests were performed in compost, simulated aquatic environments, and natural soil. In compost, the composite degraded steadily and reached 47% biodegradation after 11 weeks. In soil, the material quickly lost much of its tensile strength, and after 6 weeks, there were signs that the surface and the internal structure had started to deform. Biodegradation in aquatic environments also caused a loss of tensile strength after only a few weeks. Because of the high filler content, excellent biodegradability, and light weight, the composite material has a low environmental footprint. The material could be used in agricultural equipment such as plant pots. Full article
(This article belongs to the Section Biocomposites)
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17 pages, 6245 KiB  
Article
Biocomposites Based on Polyethylene/Ethylene–Vinyl Acetate Copolymer/Cellulosic Fillers
by P. G. Shelenkov, P. V. Pantyukhov, A. V. Krivandin, A. A. Popov, B. B. Khaidarov and M. Poletto
J. Compos. Sci. 2024, 8(11), 464; https://doi.org/10.3390/jcs8110464 - 8 Nov 2024
Viewed by 579
Abstract
This work studied biocomposites based on a blend of low-density polyethylene (LDPE) and the ethylene–vinyl acetate copolymer (EVA), filled with 30 wt.% of cellulosic components (microcrystalline cellulose or wood flour). The LDPE/EVA ratio varied from 0 to 100%. It was shown that the [...] Read more.
This work studied biocomposites based on a blend of low-density polyethylene (LDPE) and the ethylene–vinyl acetate copolymer (EVA), filled with 30 wt.% of cellulosic components (microcrystalline cellulose or wood flour). The LDPE/EVA ratio varied from 0 to 100%. It was shown that the addition of EVA to LDPE increased the elasticity of biocomposites. The elongation at break for filled biocomposites increased from 9% to 317% for microcrystalline cellulose and from 9% to 120% for wood flour (with an increase in the EVA content in the matrix from 0 to 50%). The biodegradability of biocomposites was assessed both in laboratory conditions and in open landfill conditions. The EVA content in the matrix also affects the rate of the biodegradation of biocomposites, with an increase in the proportion of the copolymer in the polymer matrix corresponding to increased rates of biodegradation. Biodegradation was confirmed gravimetrically by weight loss, an X-ray diffraction analysis, and the change in color of the samples after exposition in soil media. The prepared biocomposites have a high potential for implementation due to the optimal combination of consumer properties. Full article
(This article belongs to the Section Biocomposites)
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14 pages, 4579 KiB  
Article
Development and Evaluation of Thread Transistor Based on Carbon-Nanotube Composite Thread with Ionic Gel and Its Application to Logic Gates
by Hiroki Kodaira and Takahide Oya
J. Compos. Sci. 2024, 8(11), 463; https://doi.org/10.3390/jcs8110463 - 8 Nov 2024
Viewed by 514
Abstract
We propose a new type of flexible transistor based on carbon-nanotube (CNT) composite thread (CNTCT), i.e., a thread transistor, with ionic gel. In our previous study, we demonstrated that transistor operation was possible by combining metallic and semiconducting CNTCTs as gate and channel [...] Read more.
We propose a new type of flexible transistor based on carbon-nanotube (CNT) composite thread (CNTCT), i.e., a thread transistor, with ionic gel. In our previous study, we demonstrated that transistor operation was possible by combining metallic and semiconducting CNTCTs as gate and channel with an insulating material. However, its performance was not sufficient. Therefore, we here aim to improve it. For this, we tried to apply ionic gel as a dielectric layer to it. With this, the transistor was expected to be an electric-double-layer transistor. The transistor performance was improved, and the on/off ratio of the transistor increased by more than 4. This is a large value compared to our previous work. In addition, we not only evaluated the performance of the transistors, but also investigated whether they could be used as logic circuits. It was confirmed that the logic circuit composed of the thread transistor also operated correctly and stably for a long period of time. It was also confirmed that the output changed in response to weak external forces. These results indicate that it is a flexible transistor that can be used in a wide range of applications such as logic circuits and sensors. Full article
(This article belongs to the Special Issue Recent Progress in Hybrid Composites)
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25 pages, 8179 KiB  
Review
Recent Experimental Advances in Solid–Liquid Composites for Impact and Blast Mitigation
by Mingzhe Li, Robert McCoy and Weiyi Lu
J. Compos. Sci. 2024, 8(11), 462; https://doi.org/10.3390/jcs8110462 - 8 Nov 2024
Viewed by 711
Abstract
The development of high-performance composites for mechanical energy dissipation during impact or explosive events is of vital importance for the safety of personnel and infrastructures. Solid–liquid composites are an emerging class of energy absorbers where a liquid-phase filler is seamlessly integrated into a [...] Read more.
The development of high-performance composites for mechanical energy dissipation during impact or explosive events is of vital importance for the safety of personnel and infrastructures. Solid–liquid composites are an emerging class of energy absorbers where a liquid-phase filler is seamlessly integrated into a solid matrix to enhance the impact resistance of the protection target. This innovative approach leverages the distinct properties of both phases and the unique interactions between them to achieve superior performance under high-impact conditions. This paper aims to review the liquid-phase materials used in solid–liquid composites, ranging from neat liquids to complex fluids, including liquid nanofoam and shear-thickening fluids, to provide an in-depth analysis of the fundamental physics underpinning the resulting solid–liquid composites, and to explore how their unique properties contribute to enhanced impact resistance and energy absorption. Furthermore, this paper evaluates the advantages and limitations of these solid–liquid composites and offers insights into future directions for the development of solid–liquid composites in various fields, including personal protective equipment, automotive safety systems, and structural protection. Full article
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20 pages, 27328 KiB  
Article
Enhancing Wear Resistance of AA7075/SiC/Fly Ash Composites Through Friction Stir Processing
by Namdev Ashok Patil, Santoshi Pedapati and Srinivasa Rao Pedapati
J. Compos. Sci. 2024, 8(11), 461; https://doi.org/10.3390/jcs8110461 - 7 Nov 2024
Viewed by 571
Abstract
In this study, the wear behavior of AA7075/silicon carbide/fly ash hybrid surface composites processed with a clean and green friction stir processing technique was investigated. The microstructure of the composites was investigated to determine the particle dispersion. Wear tests using a pin-on-disc tribometer [...] Read more.
In this study, the wear behavior of AA7075/silicon carbide/fly ash hybrid surface composites processed with a clean and green friction stir processing technique was investigated. The microstructure of the composites was investigated to determine the particle dispersion. Wear tests using a pin-on-disc tribometer were conducted, and wear tracks and debris analyses were conducted using scanning electron microscopic imaging, EDX, and mapping. The wear rate of the composites was higher in the case of the composites with agglomerated zones, which led to the loose SiC/fly ash particles pulling out during the action of dry sliding. However, on the other hand, the wear resistance was improved in the composites with uniformly distributed SiC/fly ash particles. The hard SiC/fly ash particles acted as optimized load-bearing asperities and induced more wear resistance during the action of dry sliding against the mating plate, which was made of mild steel. In the case of the well-dispersed composites, the wear mechanisms shifted from fretting fatigue and adhesion to abrasion. The presence of a high Fe content in the wear debris was confirmed in the most wear-resistant composite sample, S-20, which was produced with the following parameters: tool rotation (w) of 1000 rpm, tool traverse (v) of 40 mm/min, hybrid ratio (HR) of 75:25, and a volume percentage of reinforcements (vol.%) of 8. Full article
(This article belongs to the Special Issue Welding and Friction Stir Processes for Composite Materials)
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24 pages, 3304 KiB  
Review
Tungsten Disulfide-Based Materials and Their Conjugates for Cancer Photothermal Therapy
by Ana Rita Lopes, Fernão D. Magalhães, Joana A. Loureiro and Artur M. Pinto
J. Compos. Sci. 2024, 8(11), 460; https://doi.org/10.3390/jcs8110460 - 7 Nov 2024
Viewed by 494
Abstract
Cancer remains one of the most critical global health issues. Conventional treatments, such as radiotherapy, surgery, or chemotherapy, have limitations, especially concerning side effects, resistance, and recurrence. Consequently, new innovative treatments to overcome these problems are needed. Photothermal therapy (PTT) is a promising [...] Read more.
Cancer remains one of the most critical global health issues. Conventional treatments, such as radiotherapy, surgery, or chemotherapy, have limitations, especially concerning side effects, resistance, and recurrence. Consequently, new innovative treatments to overcome these problems are needed. Photothermal therapy (PTT) is a promising alternative that uses photothermal agents that convert near-infrared light (NIR) into heat to kill cancer cells. Nanoparticles can be used as photothermal agents and also as drug delivery platforms, improving the drugs’ stability, allowing for targeted delivery, and reducing toxicity. Due to its broad absorption band, high surface area, and versatility for surface functionalization, tungsten disulfide (WS2) has high potential in this context. This paper presents the state-of-the-art on the use of WS2-based materials to achieve effective and biocompatible new anticancer treatment strategies. Full article
(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2024)
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91 pages, 36341 KiB  
Review
Cryogenic Impact on Carbon Fiber-Reinforced Epoxy Composites for Hydrogen Storage Vessels
by Omar Dagdag and Hansang Kim
J. Compos. Sci. 2024, 8(11), 459; https://doi.org/10.3390/jcs8110459 - 6 Nov 2024
Viewed by 752
Abstract
Carbon fiber-reinforced epoxy (CF/EP) composites are attractive materials for hydrogen storage tanks due to their high strength-to-weight ratio and outstanding chemical resistance. However, cryogenic temperatures (CTs) have a substantial impact on the tensile strength and interfacial bonding of CF/EP materials, producing problems for [...] Read more.
Carbon fiber-reinforced epoxy (CF/EP) composites are attractive materials for hydrogen storage tanks due to their high strength-to-weight ratio and outstanding chemical resistance. However, cryogenic temperatures (CTs) have a substantial impact on the tensile strength and interfacial bonding of CF/EP materials, producing problems for their long-term performance and safety in hydrogen storage tank applications. This review paper investigates how low temperatures affect the tensile strength, modulus, and fracture toughness of CF/EP materials, as well as the essential interfacial interactions between carbon fibers (CFs) and the epoxy matrix (EP) in cryogenic environments. Material toughening techniques have evolved significantly, including the incorporation of nano-fillers, hybrid fibers, and enhanced resin formulations, to improve the durability and performance of CF/EP materials in cryogenic conditions. This review also assesses the hydrogen barrier properties of various composites, emphasizing the importance of reducing hydrogen permeability in order to retain material integrity. This review concludes by highlighting the importance of optimizing CF/EP composite design and fabrication for long-term performance and safety in hydrogen storage systems. It examines the prospects for using CF/EP composites in hydrogen storage tanks, as well as future research directions. Full article
(This article belongs to the Section Fiber Composites)
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21 pages, 2811 KiB  
Review
Innovations and Challenges in Semi-Transparent Perovskite Solar Cells: A Mini Review of Advancements Toward Sustainable Energy Solutions
by Xiangzhi Tan and Yuanzhe Li
J. Compos. Sci. 2024, 8(11), 458; https://doi.org/10.3390/jcs8110458 - 6 Nov 2024
Viewed by 641
Abstract
Amid the shift away from fossil fuels, third-generation perovskite solar cells (PSCs) have become pivotal due to their high efficiency and low production costs. This review concentrates on semi-transparent perovskite solar cells (ST-PSCs), highlighting their power conversion efficiency (PCE) and average visible transmittance [...] Read more.
Amid the shift away from fossil fuels, third-generation perovskite solar cells (PSCs) have become pivotal due to their high efficiency and low production costs. This review concentrates on semi-transparent perovskite solar cells (ST-PSCs), highlighting their power conversion efficiency (PCE) and average visible transmittance (AVT). We address strategies to optimize ST-PSC performance, tackling inherent challenges, such as optical losses from reflection, parasitic absorption, and thermalization loss, which impact the operational efficiency under variable environmental conditions. ST-PSCs are distinguished by their lightweight, flexible, and translucent properties, allowing for diverse applications in urban building integration, agricultural greenhouses, and wearable technology. These cells integrate seamlessly into various settings, enhancing energy harnessing without compromising on aesthetic or structural elements. However, the scalability of ST-PSCs involves challenges related to stability and efficiency in large-scale deployments. The tropical urban landscape of Singapore provides a unique case study for ST-PSC application, blending architectural aesthetics with high solar irradiance to optimize energy efficiency. While the potential for ST-PSCs to contribute to sustainable urban development is immense, significant technological hurdles must be overcome to realize their full potential. Continued advancements in material science and engineering are essential to address these challenges, ensuring the scalability and long-term deployment of ST-PSCs in global energy solutions. Full article
(This article belongs to the Section Composites Applications)
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27 pages, 9044 KiB  
Review
Comprehensive Review of Hydrogel Synthesis, Characterization, and Emerging Applications
by Arumugasamy Sathiya Priya, Rajaraman Premanand, Indhumathi Ragupathi, Vijayabhaskara Rao Bhaviripudi, Radhamanohar Aepuru, Karthik Kannan and Krishnamoorthy Shanmugaraj
J. Compos. Sci. 2024, 8(11), 457; https://doi.org/10.3390/jcs8110457 - 4 Nov 2024
Viewed by 2233
Abstract
Hydrogels play a crucial role due to their high-water content and 3D structure, which make them ideal for various applications in biomedicine, sensing, and beyond. They can be prepared from a variety of biomaterials, polymers, and their combinations, allowing for versatility in properties [...] Read more.
Hydrogels play a crucial role due to their high-water content and 3D structure, which make them ideal for various applications in biomedicine, sensing, and beyond. They can be prepared from a variety of biomaterials, polymers, and their combinations, allowing for versatility in properties and applications. Hydrogels include natural types derived from collagen, gelatin, alginate, and hyaluronic acid, as well as synthetic types based on polyethylene glycol (PEG), polyvinyl alcohol (PVA), and polyacrylamide (PAAm). Each type possesses distinct properties, such as mechanical strength, biodegradability, and biocompatibility, which can be tailored for applications such as wound healing, contact lenses, 3D bioprinting, and tissue engineering. The high-water content of hydrogels mimics natural tissue environments, promoting cell growth and allowing nutrient and waste exchange, which supports the development of functional tissues. They serve as scaffolds in tissue engineering applications, including wound healing, cartilage and bone regeneration, vascular tissue engineering, and organ-on-a-chip systems. Additionally, hydrogels can encapsulate and deliver therapeutic agents, such as growth factors or drugs, to specific target sites in the body. Hydrogels can be prepared through three primary methods: physical crosslinking, which relies on non-covalent interactions such as physical entanglements or hydrogen bonding; chemical crosslinking, which forms covalent bonds between polymer chains to create a stable structure; and irradiation-based crosslinking, where UV irradiation induces rapid hydrogel formation. The choice of crosslinking method depends on the desired properties and applications of the hydrogel. By providing a biomimetic environment, hydrogels facilitate cell growth and differentiation, support tissue formation, and aid in the regeneration of damaged or diseased tissues while delivering therapeutic agents. This review focuses on the critical advancements in processing routes for hydrogel development, summarizing the characterization and application of hydrogels. It also details key applications, including wound healing and cartilage and bone regeneration, as well as the challenges and future perspectives in the field. Full article
(This article belongs to the Section Biocomposites)
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23 pages, 10593 KiB  
Article
Mechanical, Durability, and Microstructure Characterization of Pervious Concrete Incorporating Polypropylene Fibers and Fly Ash/Silica Fume
by Hassan Bilal, Xiaojian Gao, Liborio Cavaleri, Alamgir Khan and Miao Ren
J. Compos. Sci. 2024, 8(11), 456; https://doi.org/10.3390/jcs8110456 - 3 Nov 2024
Viewed by 1085
Abstract
Pervious concrete, because of its high porosity, is a suitable material for reducing the effects of water precipitations and is primarily utilized in road pavements. In this study, the effects of binder-to-aggregate (B/A) ratios, as well as mineral admixtures with and without polypropylene [...] Read more.
Pervious concrete, because of its high porosity, is a suitable material for reducing the effects of water precipitations and is primarily utilized in road pavements. In this study, the effects of binder-to-aggregate (B/A) ratios, as well as mineral admixtures with and without polypropylene fibers (PPFs) (0.2% by volume), including fly ash (FA) or silica fume (SF) (10% by substitution of cement), on the mechanical properties and durability of pervious concrete were experimentally observed. The experimental campaign included the following tests: permeability, porosity, compressive strength, splitting tensile strength, and flexural strength tests. The durability performance was evaluated by observing freeze–thaw cycles and abrasion resistance after 28 d curing. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA-DTA), and scanning electron microscopy (SEM) combined with energy dispersive spectroscopy (EDS) were employed to investigate the phase composition and microstructure. The results revealed that, for an assigned B/A ratio identified as optimal, the incorporation of mineral admixtures and fibers mutually compensated for their respective negative effects, resulting in the effective enhancement of both mechanical/microstructural characteristics and durability properties. In general, pervious concrete developed with fly ash or silica fume achieved higher compressive strength (>35 MPA) and permeability of 4 mm/s, whereas the binary combination of fly ash or silica fume with 0.2% PPFs yielded a flexural strength greater than 6 MPA and a permeability of 6 mm/s. Silica fume-based pervious concrete exhibited excellent performance in terms of freeze–thaw (F-T) cycling and abrasion resistance, followed by fiber-reinforced pervious concrete, except fly ash-based pervious concrete. Microstructural analysis showed that the inclusion of fly ash or silica fume reduced the harmful capillary pores and refined the pore enlargement caused by PPFs in the cement interface matrix through micro-filling and a pozzolanic reaction, leading to improved mechanical and durability characteristics of pervious concrete. Full article
(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)
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22 pages, 12444 KiB  
Article
Rapid Prediction and Parameter Evaluation of Process-Induced Deformation in L-Shape Structures Based on Feature Selection and Artificial Neural Networks
by Qingchuan Liu, Xiaodong Wang, Zhidong Guan and Zengshan Li
J. Compos. Sci. 2024, 8(11), 455; https://doi.org/10.3390/jcs8110455 - 3 Nov 2024
Viewed by 560
Abstract
The process-induced deformation (PID) during the manufacturing of thermosetting composite materials can significantly compromise manufacturing precision. This paper introduces an innovative method that combines a finite element analysis (FEA), feature classification algorithms, and an Artificial Neural Network (ANN) framework to rapidly predict the [...] Read more.
The process-induced deformation (PID) during the manufacturing of thermosetting composite materials can significantly compromise manufacturing precision. This paper introduces an innovative method that combines a finite element analysis (FEA), feature classification algorithms, and an Artificial Neural Network (ANN) framework to rapidly predict the PID of a typical L-shaped structure. Initially, a comprehensive range of parameters that influence PID are compiled in this research, followed by the generation of a dataset through FEA considering viscoelastic constitutive models, validated by experimental results. Influential parameters are classified using Random Forest and LASSO regression methods, with each parameter rated according to its impact on PID, delineating their varying degrees of importance. Subsequently, through a hyperparameter analysis, an ANN framework is developed to rapidly predict the PID, while also refining the assessment of the parameters’ significance. This innovative approach achieves a computational time reduction of 98% with less than a 5% loss in accuracy, and highlights that under limited computational conditions, considering only a subset or all of the parameters—the peak temperature, corner angle, coefficient of chemical shrinkage, coefficient of thermal expansion, curing pressure, and E1—minimizes accuracy loss. The study demonstrates that machine learning algorithms can effectively address the challenge of predicting composite material PID, providing valuable insights for practical manufacturing applications. Full article
(This article belongs to the Section Composites Modelling and Characterization)
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