Search Results (30,034)

Graphene incorporation into polymer fibers offers a strategy to tune nanoscale morphology while preserving mechanical conformity for flexible composite applications. Graphene-based dopants can enable modulation of polymer fiber structure; however, the relationship between graphene incorporation, fiber morphology, and mechanical flexibility must be evaluated. This study investigates the integration of graphene oxide (GO) and reduced graphene oxide (RGO) into fibrous materials to tailor the structural and surface characteristics by fabricating GO- and RGO-enhanced poly(vinylidene fluoride) (PVDF) fibers via a wet-spinning process and examining the tunability of their morphology and its influence on mechanical properties. The effect of graphene doping and reduction state on fiber architecture is explored using scanning electron microscopy (SEM), atomic force microscopy (AFM), and Brunauer–Emmett–Teller (BET) surface area analysis. Fourier transform infrared (FTIR) and Raman spectroscopy analyses confirmed the incorporation and reduction of graphene derivatives within the PVDF matrix while revealing corresponding changes in chemical functionality and the piezoelectric phase of PVDF. Mechanical flexibility is assessed through tensile testing, revealing increased stiffness with graphene addition, although maintaining sufficient structural integrity for wearable applications. These results collectively demonstrate that graphene doping provides a facile route to engineer composite fibers, enabling a balance between morphological complexity and mechanical compliancy, while establishing graphene-enhanced fibers as promising materials for flexible sensing systems and wearable smart textiles. Full article

Bulk metallic glasses (BMGs) are a type of amorphous metal with a high degree of mechanical strength, elasticity and corrosion resistance, properties that are highly influenced by composition and the processing of the material. BMGs can be applied in advanced engineering fields, such as aerospace, biomedical, MEMS, and industrial applications. Additive manufacturing (AM) is revolutionary in producing intricate BMG parts whilst maintaining the amorphous structure. The current review critically evaluates the recent development in AM of BMGs, such as the development of selective laser melting, electron beam melting, and directed energy deposition, and new classes of hybrid strategies. Enhancements in dimensional accuracy, amorphous retention, microstructural tailoring and functional performance are emphasized along with computational and real-time process optimization strategies to improve overall manufacturing efficiency and material quality. Subsequently, the challenges that still exist are addressed in the review, including crystallization during printing, the buildup of stress, printable thickness, complicated geometries, oxidation, contamination, and heterogeneous amorphous fractions. Lastly, multi-material printing, scalable AM approaches, and AI-assisted design solutions are key features of future perspectives to solve existing restrictions. The review provides an excellent guidance for the researcher and engineer interested in advancing additive manufacturing of BMGs with the best structure–property relations. Full article

The trade-off between strength and ductility remains a pivotal challenge in the development of multi-principal element alloys (MPEAs) for structural applications. Here, we report a dual-scale ordering strategy to achieve triple strengthening in a Ni-26.6Co-18.4Cr-5.4Nb-4.1Mo-2.3Al-0.3Ti-0.05Y (wt.%) MPEA through the synergistic interplay of L1₂ nanoprecipitates and local chemical order (LCO). The alloy was processed via cold rolling followed by aging at 750 °C for 8 h, resulting in a high density of coherent L1₂ precipitates (average size 47 ± 1 nm, volume fraction ~27%) with an ultra-low lattice misfit of 0.5%. Additionally, sub-nanoscale LCO domains with an average diameter of 0.62 nm were identified within the face-centered cubic matrix. This hierarchical microstructure yields an exceptional combination of mechanical properties at room temperature: yield strength of 1480 ± 6 MPa, ultimate tensile strength of 1678 ± 10 MPa, and a total elongation of 13.9 ± 0.2%. Quantitative strengthening analysis reveals that precipitation strengthening (697 MPa) is the dominant contributor, followed by dislocation strengthening (397 MPa). Transmission electron microscopy characterization of deformed samples reveals that the low stacking fault energy, promoted by LCO, facilitates the dissociation of perfect dislocations and the formation of extensive stacking faults. The intersection of stacking faults on different {111} planes generates a large number of Lomer–Cottrell locks, which significantly enhance work hardening and delay plastic instability. The findings demonstrate that engineering dual-scale ordered structures offers a promising pathway for developing MPEAs with a superior strength-ductility combination. Full article

The effect of structure on the properties of cotton fibers is yet to be fully understood even after many years of research. This is due to the presence of convolutions that occur at various intervals in cotton fibers. An attempt was made in this investigation to remove these convolutions using liquid ammonia treatment. The optical and X-ray orientation angles of two varieties of G. hirsutum cotton fibers were investigated at various stages of maturity, and results were compared. An American upland variety was also studied. Four-hour treatment of cotton fibers in liquid ammonia at a temperature of −50 °C ensures a complete change of the lattice structure from cellulose I polymorph to cellulose III polymorph. The cellulose I lattice structure is restored by boiling it in distilled water for 24 h. X-ray diffractograms confirm these conversions. Mature fibers after treatments are devoid of convolutions and are rounded in appearance with no central lumen. The scanning electron micrographs revealed these morphological structures. A close correlation exists between the optical and X-ray orientation measurements and are both strongly dependent on fiber maturity. In all the varieties studied, a maturity ratio of at least 0.8 is required for a cotton fiber to be of commercial value, in terms of strength and durability The progressive build-up of both the primary and secondary walls as the fiber matures shows a gradual decrease in helix angles and, hence, an increase in the orientation of the fibrils, conforming to the constant pitch model. The effect of convolutions on both the optical and X-ray orientation angle is found to be higher than 10%. Full article

Nitridation of different materials using ion implantation is of considerable interest for many applications. As electronic components, oxynitride (SiO_xN_y) layers exhibit beneficial properties such as precise compositional variability, refractive index tunability, oxidation resistance, and low mechanical stress. In the present study we investigate nanoscale SiO_xN_y synthesized using ion implantation methods. To introduce N⁺ ions into a shallow Si subsurface region, both conventional ion beam implantation and plasma immersion ion implantation with subsequent high-temperature treatment in dry O₂ are used. The optical and morphological properties and chemical bonding of formed SiO_xN_y layers were studied by applying spectroscopic ellipsometry in the range of VIS-Near IR (SE) and IR (IR-SE), Raman spectroscopy and Atomic Force Microscopy (AFM). Monte Carlo modeling of implant profiles contributed to understanding physical and chemical processes and predicted different influences of the incorporated N⁺ ions on the oxidation mechanism, confirmed by the thickness dependence of SiO_xN_y/Si layers obtained from the SE data analysis. IR-SE spectral analysis established the formation of Si-O, Si-N, Si-N-O and Si-Si chemical bonds in the grown layers. The occurrence of amorphization of the Si crystal lattice due to incorporation of high-energy N⁺ ions into the Si lattice is confirmed by the Raman and ellipsometry results. The free Si atoms can congregate, forming nanocrystalline clusters. AFM imaging revealed that both implantation methods left the surface of the resulting SiO_xN_y layers considerably smooth with similar roughness parameter values. The results of the studies imply that the technological approaches used allow the production of high-quality nanoscale silicon oxynitride films with appropriate tunable composition and properties for possible application in advanced electronic devices for nanoelectronics, optoelectronics and sensor applications. Full article

This study investigates the incorporation of toner residue (TR), derived from post-consumer printing cartridges, as an alternative filler in styrene–butadiene rubber (SBR) composites, with emphasis placed on solid waste valorization and the promotion of a circular economy. TR consists predominantly of fine particles containing thermoplastic polymers, carbon black, metal oxides, and additives, exhibiting functional potential as a partially reinforcing filler material. Composites containing 0 to 50 phr of TR were prepared and characterized in terms of rheometric properties, dispersion degree, elemental composition by X-ray fluorescence (XRF), crosslink density, scanning electron microscopy (SEM), infrared spectroscopy, Shore A hardness, abrasion resistance, tensile strength, and tear resistance. Rheometric results indicated modifications in vulcanization kinetics and a reduction in maximum torque for formulations with high TR contents, suggesting a possible diluent effect or interference with elastomeric network formation. Conversely, moderate TR concentrations promoted increased hardness, improved tensile strength, and higher crosslink density, associated with adequate particle dispersion within the matrix, as confirmed by SEM analysis. However, excessive TR loading led to increased abrasion loss and an overall reduction in mechanical performance. It is concluded that TR demonstrates technical feasibility as a partial substitute for conventional fillers in SBR composites, with potential industrial application, such as in footwear sole prototypes, combining functional performance with environmental impact mitigation. Full article

Two-dimensional materials have broad application prospects in the field of optoelectronic devices. As a next-generation power electronic device, AlN materials have obvious advantages in power processing, and their monolayer structure has excellent optoelectronic properties, which is of great significance for the study of 2D AlN monolayers. Properties such as electronic and optical properties of metal-adsorbed AlN (M-AlN) systems have been systematically investigated using density functional theory from first principles. The results of the energy bands of the M-AlN system indicate that the adsorption of Al, Li, Ag, Au, Bi, Cr, Mn, Na, Pb, Sn, Ti, and K metals makes the monolayer AlN magnetic, the incorporation of two metals, Al and Li, is the transition of the monolayer AlN from a semiconductor to a semi-metal, and the introduction of K metal makes the monolayer AlN transition from a semiconductor to a metal. The work function of the M-AlN system shows that the introduction of the metal reduces the work function of the monolayer AlN, especially for K-AlN, which is reduced by 56.12% compared to the monolayer AlN. In addition, the results of the optical absorption spectra of the M-AlN system revealed that the introduction of the metals made the monolayer AlN exhibit high absorption peaks in the visible and near-infrared regions; in particular, the intensity of the absorption peaks of the Ti-AlN system at 557.8 nm reached 7.4 × 10⁴ cm⁻¹ and the intensity of the absorption peaks of the K-AlN system at 1109.3 nm reached 1.01 × 10⁵ cm⁻¹. This indicates that the introduction of Ti and K metal atoms enhances the absorption properties of monolayer AlN in the visible and near-infrared regions. Finally, the time-domain finite difference using spherical metal nanoparticles is used to excite the localized surface plasmon resonance, and the results show a small area of strong electric field around the electric field hotspot of Cr and Li particles, and a good concentration of the electric field strength in the x and y directions. In summary, the system of metal atoms adsorbed on AlN will be favorable for the design of spintronics, field-emitting devices and solar photovoltaic devices. Full article

This study investigates the preparation and performance of ultra-high-performance concrete (UHPC) incorporating manufactured sand as a full replacement for quartz sand. The mix design was optimized by integrating the compressible packing model (CPM) with an orthogonal experimental design. The influence of stone powder content in manufactured sand—0, 5, 10, and 15% by mass of fine aggregate—on fresh-state fluidity and 7d-mechanical properties was systematically evaluated. Hydration products and microstructural features were analyzed using X-ray diffraction (XRD), scanning electron microscope (SEM), and mercury intrusion porosimetry (MIP). Results show that the manufactured sand-based UHPC achieved a fresh-state fluidity of 185 mm and a 7-day compressive strength of 152.4 MPa. Both fluidity and compressive strength exhibited a unimodal trend with increasing stone powder content, reaching maxima at 10%. Microstructural analysis revealed intimate interfacial bonding between unhydrated particles and calcium silicate hydrate (C–S–H) gel; notably, the UHPC matrix with 10% stone powder displayed the densest microstructure. MIP results further demonstrated that an optimal stone powder content effectively reduced total porosity, with the lowest overall porosity and the highest volume fractions of harmless (≤20 nm) and less harmful (20–100 nm) pores observed at 10%. These microstructural refinements collectively underpin the superior mechanical performance of manufactured sand-based UHPC. Full article

In this study, NH₂-MgO was employed as a crosslinking agent to covalently link boron nitride (BN) and silicon carbide whiskers (SiC_w) via an amidation reaction, yielding the BN-MgO-SiC_w hybrid filler. The BN-MgO-SiC_w/PBz composites were fabricated using a ball-milling-assisted solution mixing method combined with hot-press molding, and their comprehensive properties were systematically evaluated. The results demonstrate that the BN-MgO-SiC_w/PBz composite exhibits excellent thermal conductivity, favorable dielectric properties, superior thermal stability, and outstanding mechanical performance. At a filler loading of 50 wt%, the composite achieved a thermal conductivity of 1.41 W/mK, which is substantially higher than that of the KH560-BN/PBz composite (0.91 W/mK) and approximately 5.2 times that of the neat PBz matrix. The dielectric constant (ε) and dielectric loss (tan δ) of the BN-MgO-SiC_w/PBz composite were 6.81 and 0.013, respectively, remaining at relatively low levels. The thermal degradation temperature at 30% weight loss (T₃₀) and the heat resistance index temperature (T_HRI) reached 572 °C and 244 °C, respectively, both higher than those of the KH560-BN/PBz composite at the same filler loading (511 °C and 224 °C). The tensile strength and flexural strength of the BN-MgO-SiC_w/PBz composite were 50.0 MPa and 72.3 MPa, respectively, exceeding those of the KH560-BN/PBz composite (39.4 MPa and 56.2 MPa) while remaining slightly below those of the neat PBz matrix. Collectively, these findings indicate that the BN-MgO-SiC_w/PBz composite holds great promise as a novel material with well-balanced comprehensive properties, making it a strong candidate for applications in fields such as electronic packaging. Full article

Flexible X-ray detectors have emerged as a promising technology for portable medical imaging and wearable electronics, yet their manufacturing remains constrained by the competing requirements of device performance, mechanical conformability, and production scalability. Conventional solution-based deposition methods fail to yield high-quality perovskite thick films with uniform morphology, while vacuum evaporation techniques are limited by exorbitant operational costs and low throughput. Herein, we report an optimized solution-processed vacuum evaporation strategy that enables the fabrication of high-quality perovskite films (~1 μm thick) on flexible polyethylene naphthalate (PEN) substrates at a low processing temperature of 100 °C. By incorporating tailored additives into the precursor solution and precisely modulating the vapor-phase conversion kinetics, we achieved significant improvements in film density, crystallinity, and morphological uniformity. Systematic investigations were conducted to elucidate the structure–property relationships across three material systems: pure methylammonium lead iodide (MAPbI₃), halogen-doped methylammonium lead iodide-bromide (MAPb(IBr)₃), and synergistic cation-halogen engineered cesium-methylammonium lead iodide-bromide (CsMAPb(IBr)₃). The optimized flexible PIN-type X-ray detector based on CsMAPb(IBr)₃ exhibited exceptional performance metrics, including a dark current density as low as 5.2 nA cm⁻² and an X-ray sensitivity of up to 1.43 × 10⁴ μC·Gy_air⁻¹·cm⁻². Remarkably, the device retained over 95% of its initial performance after 400 bending cycles with a bending radius of 6 mm, demonstrating outstanding mechanical robustness and operational durability. This work establishes a viable, cost-effective technical route for the scalable production of high-performance flexible X-ray detectors, addressing critical challenges in the advancement of next-generation portable imaging technologies. Full article

Gas-filled discharge capillaries are widely used in the field of plasma-based particle accelerators, due to their compactness, cost-effectiveness and versatility for different applications. Technological improvement of such plasma sources is necessary to enable high energy gain acceleration at the meter scale, as required for next-generation particle colliders and light sources. Beam quality preservation within such an acceleration length involves accurate tuning of the plasma properties. In particular, precise tailoring of the plasma density distribution is required to control the emittance growth of particle bunches during the acceleration process. In this context, this paper presents a scalable and versatile approach for the design of meter-scale discharge capillaries, aimed at achieving fine tuning of the plasma density distribution, with the possibility of locally controlling the density profile by acting on the source geometry. Forty-centimeter-long capillaries are designed using numerical fluid dynamics simulations and tested in a dedicated plasma module. Different arrangements of the gas inlets are tested, with their number and diameter varied, to assess the effect of the capillary geometry on the plasma properties. Plasma density measurements show that a higher number of inlets with variable diameter along the plasma formation channel provides an enhancement in the homogeneity of the electron plasma density distribution. Longitudinal density plateaus are observed along most of the plasma channel length, with a center-to-end density uniformity of up to 80%. The experimental results highlight the proposed approach’s capability to modulate the longitudinal plasma density distribution by acting on the capillary geometry, thus providing uniform density profiles over the meter scale, as required for plasma-based acceleration experiments. Full article

Activated sludge treatment is plagued by high secondary pollution risks, and ship antifouling paint particles (APPs) as hazardous heavy metal-rich solid wastes generated from hull derusting wastewater, pose severe environmental threats and intractable disposal dilemmas. This study developed a novel pilot-scale activated sludge reduction process coupling APPs-derived carbon-based catalysts with ultrasound-Fe²⁺/peroxydisulfate (PDS) advanced oxidation. Columnar catalysts were fabricated via direct carbonization-molding using waste APPs from an 82,000 deadweight bulk carrier were used as the sole raw material to prepare columnar catalysts via direct carbonization-molding; single-factor and orthogonal experiments optimized process parameters, Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray Photoelectron Spectroscopy (XPS) characterized catalyst and sludge properties, free radical quenching experiments elucidated reaction mechanisms and a 90-day continuous pilot run assessed catalytic stability. The process achieved a 43.5% sludge removal rate under optimal conditions, accompanied by 100% toluene and 92.3% phenolic compound degradation, as well as efficient total phosphorus (TP) and total nitrogen (TN) removal. Mechanistic studies via characterization and quenching experiments confirmed the catalyst enhanced PDS activation through free/non-free radical synergy and accelerated Fe²⁺/Fe³⁺ redox cycling. A 90-day continuous pilot operation demonstrated excellent long-term catalytic stability, with sludge removal rate remaining above 38%. This “waste treating waste” technology realizes high-value APPs resource utilization, provides a low-carbon sludge disposal pathway, and offers a scalable solution for collaborative pollution control in the wastewater treatment and shipping industries. Full article

Calcium carbonate is a widely used filler in polymer composites due to its low cost and ability to improve stiffness, dimensional stability, and impact resistance. However, its hydrophilic surface limits compatibility with nonpolar polymer matrices, making surface modification essential to improve filler dispersion and interfacial adhesion. Stearic acid is commonly applied as a surface modifier for calcium carbonate because it readily chemisorbs onto the mineral surface and forms densely packed self-assembled monolayers that improve hydrophobic character. Despite its widespread use, stearic acid exhibits limited thermal and interfacial stability under polymer processing conditions, motivating the development of stabilization strategies. In this work, gamma and electron-beam irradiation were applied to stearic-acid-modified calcium carbonate to modify the surface-bound stearic acid layer with the aim of enhancing its interfacial stability, surface resistance, and hydrophobic performance, and to evaluate the influence of irradiation atmosphere on these effects. The modified materials were characterized in terms of structural integrity, surface wettability, surface free energy, thermal stability, and optical properties. The results demonstrate that ionizing radiation enhances surface hydrophobicity and coating durability while preserving the crystal structure of the CaCO₃ substrate. Gamma irradiation of stearic-acid-modified vaterite exhibited strong atmosphere dependence, with improved hydrophobicity under oxygen-free conditions, whereas electron-beam irradiation showed more robust and oxygen-insensitive behavior. Based on the observed improvements in hydrophobicity, surface free energy, and thermal stability, electron-beam irradiation emerges as a promising and less atmosphere-sensitive approach for producing durable stearic-acid-modified CaCO₃ fillers suitable for polymer composite applications. Full article

In previous studies, it was established that replacing cement with dispersed glass from various electronic and household devices is challenging due to the formation of agglomerates in the mixture. Therefore, this study addresses this problem by applying different methods for incorporating dispersed glass: mixing in a conventional Hobart-type mixer, mixing dry components in an intensive Eirich-type mixer, and dispersing the glass particles in water using ultrasonic treatment. Using these 3 glass waste incorporation methods, the properties of hardened cement paste—density, compressive strength, phase composition, and microstructure—were compared. The effects of 4 types of glass (from television screens, washing machines, fluorescent lamps, and solar panels) were analysed. The results showed that lamp glass dispersed in water with ultrasound showed the best performance, while for the other glass types, intensive mixing was more effective. Under these conditions, the compressive strength of the samples increased by up to approximately 24%, and a denser microstructure was obtained compared to other glass incorporation methods. Full article

Plastic pollution from packaging waste is driving the development of biodegradable composites for sustainable packaging. In this work, poly(butylene adipate-co-terephthalate)/poly(3-hydroxybutyrate) (PBAT/PHBH) blends (50/50 wt.%) were reinforced with agro-industrial waste fillers—spent coffee grounds (SCG), brewer’s spent grain (BSG), and cellulose powder (CP)—at 1–15 wt.% loading. The effects of these fillers on tensile properties, impact strength, and thermal stability were examined and supported by scanning electron microscopy (SEM) of fracture surfaces and thermogravimetric analysis (TGA). The neat PBAT/PHBH blend exhibited balanced stiffness and ductility. Low BSG loadings (≤5 wt.%) produced the greatest toughening, with impact strength increasing by ~92% and elongation at break significantly improving over the neat blend. SEM analysis indicated crack deflection and particle pull-out as dominant energy-dissipation mechanisms at low BSG loading. At higher BSG loading (15 wt.%), particle clustering and larger voids acted as stress concentrators, reducing impact performance. SCG improved ductility at low loading (1 wt.%), whereas increasing SCG content led to progressive reductions in tensile strength and elongation due to increased debonding and microvoid formation. In contrast, CP exhibited minimal reinforcement efficiency within the investigated range (1–5 wt.%). Overall, filler addition generally reduced tensile strength and, in several cases, tensile modulus, reflecting limited interfacial compatibility between the hydrophilic lignocellulosic fillers and the hydrophobic polyester matrix. TGA indicated a modest improvement in thermal stability at higher BSG loadings, reflected by shifts in T_5% and T_max1 (PHBH) toward higher temperatures. Overall, this study demonstrates that upcycled coffee and beer waste fillers can impart specific toughness benefits to biodegradable PBAT/PHBH blends, but interfacial incompatibility currently limits their reinforcement efficiency. The findings highlight the potential and challenges of these biocomposites for sustainable packaging applications and suggest that interface engineering (e.g., compatibilizers) will be key to unlocking optimal performance. Full article