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The degradation of β-Ga2O3-based devices' performance may occur when they are bombarded by charged particles in aerospace, astronomy, and nuclear-related applications. It is significant to explore the influence of irradiation on the microstructure of β-Ga2O3 and to reveal the internal relationship between the damage mechanisms and physical characteristics. Thus, we explored the low-energy recoil events of β-Ga2O3 based on the first-principles calculations in the present study. The threshold displacement energies (Eds) significantly depended on the recoil directions and the primary knock-on atoms. Eds of Ga atoms are generally larger than those of O atoms, indicating that the displacements of O atoms dominate under electron irradiation. In the neutral state, the formation energy of VO(I) is lower than that of VO(II) and VO(III), while in the +2 charge state, the case is a reversal. The formation energy of Oint(II) defect is high, and thus its equilibrium concentration is low, indicating that the Oint(II) defect is unlikely to be relevant for the thermal-mechanical properties of β-Ga2O3. The charged VO and Oint defects deteriorate the ability to resist external compression more profoundly, while defective β-Ga2O3 with lower Young's modulus is expected to possess higher elastic compliance than pristine β-Ga2O3. The lattice thermal conductivity of β-Ga2O3 decreases with increasing temperature and the charged point defects generally result in the decreasing lattice thermal conductivity more profoundly than neutral point defects. The presented results provide underlying mechanisms for defect generation in β-Ga2O3 and advance the fundamental understanding of the radiation resistances of semiconductor materials. [ABSTRACT FROM AUTHOR]

The degradation of β-Ga2O3-based devices' performance may occur when they are bombarded by charged particles in aerospace, astronomy, and nuclear-related applications. It is significant to explore the influence of irradiation on the microstructure of β-Ga2O3 and to reveal the internal relationship between the damage mechanisms and physical characteristics. Thus, we explored the low-energy recoil events of β-Ga2O3 based on the first-principles calculations in the present study. The threshold displacement energies (Eds) significantly depended on the recoil directions and the primary knock-on atoms. Eds of Ga atoms are generally larger than those of O atoms, indicating that the displacements of O atoms dominate under electron irradiation. In the neutral state, the formation energy of VO(I) is lower than that of VO(II) and VO(III), while in the +2 charge state, the case is a reversal. The formation energy of Oint(II) defect is high, and thus its equilibrium concentration is low, indicating that the Oint(II) defect is unlikely to be relevant for the thermal-mechanical properties of β-Ga2O3. The charged VO and Oint defects deteriorate the ability to resist external compression more profoundly, while defective β-Ga2O3 with lower Young's modulus is expected to possess higher elastic compliance than pristine β-Ga2O3. The lattice thermal conductivity of β-Ga2O3 decreases with increasing temperature and the charged point defects generally result in the decreasing lattice thermal conductivity more profoundly than neutral point defects. The presented results provide underlying mechanisms for defect generation in β-Ga2O3 and advance the fundamental understanding of the radiation resistances of semiconductor materials. [ABSTRACT FROM AUTHOR]

This study investigates the interface between ice and organic solvents using atomic force microscopy (AFM). Atomically flat ice surfaces were prepared and observed by AFM in 1-octanol, 1-hexanol, and 1-butanol. The results show differences in surface roughness influenced by the interaction of ice and alcohols. Young's modulus of ice was analyzed by force curve measurements, providing valuable insights into the properties of ice in liquid environments. The results showed the characteristics of the ice surface in different solvents, suggesting potential applications in understanding surface and interface phenomena associated with ice under realistic conditions. [ABSTRACT FROM AUTHOR]

Hexagonal boron nitride (h-BN) has excellent thermal conductivity and dielectric properties, which shows great potential for low-dimensional devices. However, mechanical properties of h-BN have not been comprehensively investigated through experiments. In this work, we conduct in situ direct tensile tests on freestanding single-crystal few-layer h-BN nanosheets with various layer numbers from 3 to 8, with an elaborate sample transfer and characterization protocol. Young's modulus of 573.8 ± 101.4 GPa and a tensile fracture strain up to 3.2% are revealed, which are comparable to its monolayer counterpart. Moreover, we find a tough-to-brittle transition in few-layer h-BN with the increase in layer number, which is attributed the interplay between the van der Waals interaction and in-plane covalent bonding. These findings could open up new possibilities in mechanical research of van der Waals materials and provide guidance for the design of h-BN-based devices and composites. [ABSTRACT FROM AUTHOR]

Metallic glasses (MGs) are of high strength but limited plasticity at room temperature (RT) due to localized shear in the intrinsically heterogeneous structure. Here, we investigate the variation of structural heterogeneity and plasticity of a Zr-based MG after high-temperature (T) tension under different stresses (σ) at 579 K (0.9Tg, where Tg is the glass transition temperature). The correlation length (ξ) of the heterogeneous structure and the average Young's modulus ( E ¯ ) increase with σ when σ is below 160 MPa; when σ exceeds 160 MPa, both ξ and E ¯ decrease with σ, leading to the improvement of the plasticity. This research could be enlightening for improving the plasticity of MGs at RT through tuning their structural heterogeneity with high-T deformation. [ABSTRACT FROM AUTHOR]

One of the primary hurdles in microdevice fabrication lies in ascertaining the most impactful tactics for adapting metal surfaces. Through a one-pot tackle and distinct mechanochemical reactions evoked by 15 min aqueous wet sand-milling (SM-15), we successfully grafted Mo-based metal–organic frameworks (Mo-MOFs) onto graphene oxides (GOs). Following this, a convenient and readily scalable methodology of electrophoretic deposition was implemented to create controllable thickness of SM-15 GOs@Mo-MOFs lubricating films, achieving considerable enhancements of 143% and 91% in hardness and Young's modulus, respectively, when compared to those of SM-15 Mo-MOFs. The successful synthesis of SM-15 GOs@Mo-MOFs was corroborated using strategies such as x-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy. Analyses using the micro-tribotester indicated that the new film exhibited a lowest friction coefficient of roughly 0.5 when imposed with a load of 5 N and sliding speed of 8 mm/s. In addition, the optical profiler nano-indentation in situ scanning probe microscope revealed that SM-15 GOs@Mo-MOFs films had smaller and shallower scratches and grooves compared to SM-15 Mo-MOFs ones. The calculated results of key descriptors (EHOMO, ELUMO, ΔE, etc.) in density functional theory quantitatively disclosed the interaction mechanisms between GOs@Mo-MOFs molecules and microdevices. We first scrutinized the innate properties of molecule adsorption energy and frictional mechanical behaviors using synergetic cross-scale simulations, such as Monte Carlo and finite element methods. The expectation was that this process would motivate a valuable technique for shielding in the thriving micromanufacturing. [ABSTRACT FROM AUTHOR]

Due to their nanoscale features, nanometric multilayers can have a large variation in properties for varying bilayer heights. While the hardening at small feature sizes and the consequent softening at even smaller feature sizes have been observed for decades, the underlying mechanisms are still under debate. In this study, molecular dynamics uniaxial compression simulations are employed to study the mechanical properties of Al/Ni multilayers for bilayer heights h from 100 nm down to 5 nm. The effect of the microstructure on Young's modulus and the yield strength was investigated. Furthermore, the mechanical properties of equiatomic and equivolumetric multilayers were compared. A comparison with experimental results from the literature showed good agreement. Both the hardening at intermediate bilayer heights as well as the softening at very small bilayer heights were observed. The results are discussed in the context of possible hardening and softening mechanisms. While the Hall–Petch effect with a h − 1 / 2 scaling is not contradicted, it is shown that, although the underlying mechanisms are different, both the hardening as well as the softening are based on a general size effect with a scaling of ln (h) / h. [ABSTRACT FROM AUTHOR]

Motivated by the recent experimental synthesis of two-dimensional (2D) NbOI2 which possesses a moderate bandgap and outstanding absorption of sunlight, using the first-principles calculations, we conduct a thorough study of the geometric configuration, electronic structures, and photocatalytic properties for NbOX2 (X = Cl, Br, I) monolayers. These NbOX2 monolayers have been demonstrated to be dynamically, thermally, and mechanically stable. The significant anisotropic mechanical properties of NbOX2 monolayers are reflected by the calculated Young's modulus and Poisson's ratio. Our results indicate that these NbOX2 materials unfold semiconductor characters with indirect bandgaps of 1.886, 1.909, and 1.813 eV, respectively. Among these monolayers, it is found that the NbOBr2 system exhibits a favorable photocatalytic activity in an acidic condition (pH = 0), and the NbOI2 monolayer can act as a potential photocatalyst for spontaneous photocatalytic water splitting under a neutral environment (pH = 7). Furthermore, the response of bandgap and band edge positions of NbOX2 monolayers to the exerting in-plane strain (–6% to 6%) are investigated. These NbOX2 monolayers also show strong light absorption from the visible to ultraviolet region and anisotropic high carrier transport. Particularly, the high solar-to-hydrogen efficiency of the NbOCl2 (1% tensile strain), NbOBr2, and NbOI2 monolayers are predicted to be 14.11% (pH = 0), 16.34% (pH = 0), and 17.05% (pH = 7), respectively. Therefore, we expect the NbOX2 monolayers to be promising candidates for highly efficient photocatalytic water splitting. [ABSTRACT FROM AUTHOR]

Due to high ion conductivity, low cost, and adjustable composition, antiperovskite has attracted much attention as a potentially useful material in solid-state batteries. Compared with simple antiperovskite, Ruddlesden–Popper (R–P) antiperovskite is an updated material, which is not only more stable but also reported to significantly enhance conductivity when added to simple antiperovskite. However, systematic theoretical research on R–P antiperovskite is scarce, hindering its further development. In this study, the recently reported easily synthesized R–P antiperovskite LiBr(Li2OHBr)2 is calculated for the first time. Comparative calculations were conducted on the transport performance, thermodynamic properties, and mechanical properties of H-rich LiBr(Li2OHBr)2 and H-free LiBr(Li3OBr)2. Our results indicate that due to the presence of protons, LiBr(Li2OHBr)2 is more prone to defects, and synthesizing more LiBr Schottky defects can improve its Li-ion conductivity. Young's modulus of the LiBr(Li2OHBr)2 is as low as 30.61 GPa, which is beneficial for its application as a sintering aid. However, the calculated Pugh's ratio (B/G) of 1.28 and 1.50, respectively, indicates that R–P antiperovskites LiBr(Li2OHBr)2 and LiBr(Li3OBr)2 exhibit mechanical brittleness, which is not conducive to its application as solid electrolytes. Through quasi-harmonic approximation, we found that the linear thermal expansion coefficient of LiBr(Li2OHBr)2 is 2.07 × 10−5 K−1, which is more advantageous in matching electrodes than LiBr(Li3OBr)2 and even simple antiperovskites. Overall, our research provides comprehensive insights into the practical application of R–P antiperovskite in solid-state batteries. [ABSTRACT FROM AUTHOR]

Due to high ion conductivity, low cost, and adjustable composition, antiperovskite has attracted much attention as a potentially useful material in solid-state batteries. Compared with simple antiperovskite, Ruddlesden–Popper (R–P) antiperovskite is an updated material, which is not only more stable but also reported to significantly enhance conductivity when added to simple antiperovskite. However, systematic theoretical research on R–P antiperovskite is scarce, hindering its further development. In this study, the recently reported easily synthesized R–P antiperovskite LiBr(Li2OHBr)2 is calculated for the first time. Comparative calculations were conducted on the transport performance, thermodynamic properties, and mechanical properties of H-rich LiBr(Li2OHBr)2 and H-free LiBr(Li3OBr)2. Our results indicate that due to the presence of protons, LiBr(Li2OHBr)2 is more prone to defects, and synthesizing more LiBr Schottky defects can improve its Li-ion conductivity. Young's modulus of the LiBr(Li2OHBr)2 is as low as 30.61 GPa, which is beneficial for its application as a sintering aid. However, the calculated Pugh's ratio (B/G) of 1.28 and 1.50, respectively, indicates that R–P antiperovskites LiBr(Li2OHBr)2 and LiBr(Li3OBr)2 exhibit mechanical brittleness, which is not conducive to its application as solid electrolytes. Through quasi-harmonic approximation, we found that the linear thermal expansion coefficient of LiBr(Li2OHBr)2 is 2.07 × 10−5 K−1, which is more advantageous in matching electrodes than LiBr(Li3OBr)2 and even simple antiperovskites. Overall, our research provides comprehensive insights into the practical application of R–P antiperovskite in solid-state batteries. [ABSTRACT FROM AUTHOR]

Sb 2 O 3 is regarded as an ideal anode material for potassium-ion batteries for its high theoretical specific capacity. However, the potassiation and depotassiation during cycling causes large volume change which will result in cracking of the electrode and irreversible loss of capacity. Here, we prepared graphene-modified Sb 2 O 3 porous carbon nanofiber by electrospinning and subsequent annealing in air as anode material of potassium-ion batteries. The mechanical properties of the electrode materials are greatly enhanced owing to the introduction of graphene with the Young's modulus increased to 3045.5 MPa from 1367.9 MPa. Ultimately, the as-prepared Sb 2 O 3 @GPCN-100 porous fibers delivered a high specific capacity of 327 mAh g−1 after 300 cycles at a current density of 500 mA g−1. Even at a high current density of 1000 mA g−1, the electrode exhibits a specific capacity of 292 mAh g−1 after 600 cycles, showing excellent reversible stability and high specific capacity. This graphene modification strategy can also provide a feasible solution for the modification of other anode materials for potassium-ion batteries. The potassium ion storage performance can be significantly improved after the introduction of graphene in Sb2O3/porous carbon fibers. [Display omitted] • Graphene modified Sb2O3/porous carbon nanofibers were prepared via electrospinning and subsequent treating in air rather than inert atmospheres. • The graphene modified Sb2O3/porous carbon nanofibers exhibit excellent potassium ion storage performance. • The improved electrochemical performances are attributed to the enhanced mechanical properties owing to the introduction of graphene. [ABSTRACT FROM AUTHOR]

Understanding rock mechanical time-dependent plastic deformation enables the researchers to accurately predict rock responses during loading and unloading. This research focuses on the geomechanical aspects of hydrogen storage, particularly rock resistance to creep deformation under varying stresses and pressures. Modelling creep deformation in underground storage mediums has been overlooked and requires further consideration, as it is a critical, cyclical, time-dependent phenomenon essential for hydrogen containment. The study's novelty is demonstrated in its focus on geomechanical properties of rock minerals, providing insights that aid in site-selection criteria for hydrogen storage A creep deformation model with varying mineral compositions is used to assess creep deformation strain. In homogenous cases, calcite showed the highest resistance to creep deformation after three loading cycles, primarily due to its high Young's Modulus. As for the heterogenous cases, the results indicated that the mixture of calcite and quartz was the most creep-resistant rock composition. In terms of rock types, basalt samples demonstrated the highest resistance to creep deformation, while siltstone exhibited the highest susceptibility to deformation. It was observed that as the number of cycles increase, the rock mechanical stability decreases, hence optimizing the number of cycles is a must to ensure hydrogen geo-containment. • Creep deformation model assessing mechanical properties of sandstones is developed using finite element. • Young's Modulus and Poisson's ratio control the extent and distribution of creep strain deformation, respectively. • Young's Modulus >70 GPa has showed remarkable creep deformation resistance. • Calcite predominantly resist creep deformation, while K-feldspar is the most susceptible by one order of magnitude. • Basalt rock demonstrated the highest resistance to creep deformation. [ABSTRACT FROM AUTHOR]

This investigation comprehensively examines the nano - mechanical properties of AlTaO 4 for the first time, including Young's modulus (E), hardness (H), and fracture toughness (K IC). Variability in the regional distribution of E and H within AlTaO 4 is elucidated through an examination spanning both the grain and bulk material scales, and offers a correlational equation of E and H from fit statistical outcomes. Additionally, the H/E ratio and micro-hardness dissipation parameter of AlTaO 4 reach 0.063 and 0.61, respectively, which demonstrate its exceptional wear resistance. Further investigation emphasizes that the distinctive crystalline structure, short bond lengths, high bond strength, and elevated charge density around aluminum ions significantly contribute to the high E (208 GPa) and H (13.1 GPa) of AlTaO 4. The capacity for energy absorption during elastic deformation enhances crack formation energy and contributes to the relatively high fracture toughness (2.6 MPa m1/2) of AlTaO 4. This work elucidates the excellent mechanical properties of AlTaO 4 by applying nanoindentation and first-principle calculation, which will advance the applications of AlTaO 4 as high-temperature materials. [ABSTRACT FROM AUTHOR]

Heptene‐graphitic nanoplatelets (HtGNP) serve as a filler for high density polyethylene (HDPE), generated through a mechanochemical reaction involving graphite and 1‐heptene. Various analyses indicate the efficient exfoliation of graphite into HtGNP, characterized by exceptional traits. Consequently, HtGNP & HDPE_5 nanocomposites, produced via the solution process, exhibit significantly increased tensile strength and Young's modulus, boasting corresponding increases of 27.7% and 13.7% compared to pure HDPE. Thus, owing to their outstanding performance, HtGNP emerges as a promising option in the form of a novel reinforcing additive for various hydrocarbon polymers. [ABSTRACT FROM AUTHOR]

Self‐powered visualized sensor with skin‐like functionality is highly anticipated for practical application in health monitoring, human‐machine interaction, and robotics. However, the existing methods are disadvantaged by their poor performance in sensitivity and spatial fidelity due to the low pixel density, brightness, or conformability. Herein, a novel self‐powered skin‐inspired visualized sensor (SP‐SIVS) is developed by means of triboelectrification‐induced electroluminescence (TIEL) technique. By integrating surface and bulk charge generation with a high‐voltage corona charging treatment, a significant improvement is achieved in the brightness (by 10‐fold) and spatial resolution (100 µm) of the SP‐SIVS. Meanwhile, Young's modulus (94 kPa) is maintained at a level comparable to human skin, with tensile strength and elongation exceeding 1000 kPa and 1000%, respectively. Furthermore, SP‐SIVS is verified as applicable to serve such purposes as wearable motion detection, fingerprint morphology imaging, and information interaction. This work contributes an innovative framework to the development of SP‐SIVS with high‐brightness, high‐resolution, and sustainability, laying a foundation for its popularization as a novel interactive medium required for advanced photonic applications. [ABSTRACT FROM AUTHOR]

In this study, a novel micromechanics-based damage model is proposed for the damage evolution of a two-component microencapsulated-based self-healing polymer composite. In this way, a representative volume element (RVE) including an epoxy matrix with randomly distributed poly(methyl methacrylate) (PMMA) microcapsules is modeled in DigimatTM software and analyzed in Abaqus®. A new technique is developed to investigate the progressive damage by pre-inserted cohesive elements along all element boundaries of the epoxy matrix, PMMA shell, and capsule-matrix interfaces with the bilinear traction–separation law. Moreover, the impact of interface bonding strength, interface fracture energy, and PMMA microcapsules volume fraction on the load-carrying capacity of the RVEs under uniaxial tension loading was studied. The results indicated that the tensile strength of the self-healing polymer composite increased as the interfacial strength and fracture energy increased from 10 to 60 MPa and 100 to 1000 J/m2, respectively. Furthermore, the higher volume fraction of 5% PMMA microcapsules results in a lower load-carrying capacity of self-healing polymer composite with a strength of 4.9 N. A similar trend of Young's modulus was observed for microcapsule-loaded epoxy composite compared to the pristine epoxy matrix. The micromechanical model has proper accuracy in predicting the tension behavior of self-healing composite in comparison to experimental results. Finally, two healing strategies are considered for the damaged RVE. [ABSTRACT FROM AUTHOR]

Ferroelectric perovskites are pivotal in diverse technological applications; however, a gap persists in our comprehension of their mechanical properties, emphasizing the need for additional exploration. In the present study, we report on the nanomechanical behavior of BiFeO 3 ceramics in the force range between 200 μN and 2 mN, including the evolution of the hardness and the reduced Young's modulus from (9.9 ± 0.4) GPa and (113.7 ± 6.9) GPa, respectively, with increasing force. A sequence of plastic-deformation mechanisms under the cube-corner probe was revealed through a first pop-in analysis in combination with a variety of electron microscopy techniques, starting with a homogeneous dislocation nucleation, multiplication and rearrangement leading to sub-grain formation, a phenomenon observed in metals but not in ceramics. [ABSTRACT FROM AUTHOR]

M-YTaO 4 is one of the most promising candidates for the next-generation thermal barrier coatings. However, the CMAS-induced degradation of M-YTaO 4 is still in dispute. This work comprehensively investigates the CMAS corrosion of M-YTaO 4 at 1300 °C which provides new insights into the corrosion mechanism. CMAS attacks M-YTaO 4 forming a thick recession layer and the main corrosion product is accurately confirmed to be (Ca 2-x Y x)(Ta 2-y-z Mg y Al z)O 7 solid solution. The recession layer presented a small difference in Young's modulus with M-YTaO 4. No delamination cracking occurred during the thermal cycling process indicating good reliability. In addition, grain boundary infiltration of CMAS is first revealed in M-YTaO 4. The results have corrected the misjudgment of the corrosion mechanism and CMAS infiltration process in previous studies which provides guidelines for the design of M-YTaO 4 thermal barrier coatings. [ABSTRACT FROM AUTHOR]

High-temperature irradiation-induced amorphization in SiC is a crucial factor leading to swelling. This study employs atomistic simulations to clarify the effects of experimental irradiation damage (1.0 dpa) in polycrystalline 3C-SiC at 1000 K. The findings reveal amorphization and swelling thresholds at 0.45 dpa and 7.45 %, respectively. Interestingly, dose threshold for amorphization does not align with chemical bonding, volume swelling, or enthalpy thresholds. Instead, a competitive mechanism emerges between grain boundaries and the grain core in the evolution of chemical disorder and clusters. Moreover, as amorphization saturates and grain boundaries annihilate, the degradation of tensile strength and Young's modulus stabilizes at 21.1 GPa and 124.2 GPa, respectively. Notably, grain boundaries exert a significant influence on defect cluster formation during amorphous evolution and dominate the initial deterioration of mechanical properties at low damage doses. This study enhances our understanding of how grain boundaries and chemical disorder mechanisms impact amorphization SiC. [ABSTRACT FROM AUTHOR]

ZrC-SiC-ZrB 2 ceramics were prepared via ultra-high pressure sintering under 15 GPa at 1200 °C. The densification mechanism, microstructures, and properties of the prepared ceramics were investigated. The sintered ceramics with ZrB 2 content of 15 vol % showed the improved comprehensive mechanical properties, including Vickers hardness of 26.6 GPa, Young's modulus of 469.1 GPa, and fracture toughness of 5.0 MPa·m1/2, which was 86.7 % higher than that of pure ZrC ceramics. In the sintered sample, the ultra-high pressure induced new microstructure, such as L-C lock in ZrC phase, stacking faults and nanotwins in SiC phase, and severe lattice distortion in ZrB 2 phase, jointly contributed to the improvement in Vickers hardness. Deflection and bridging during crack propagation were ascribed to the uniform combination of various phases. [ABSTRACT FROM AUTHOR]

Ceramics from the magnesia-alumina-silica (MAS) system are common products of the ceramic industry. The phase composition of these systems can be rather complex, especially when feldspar is added as a flux, and thus attempts to correlate the composition and structure of these ceramics to their properties are quite rare, especially when considerable amounts of glass phase and sapphirine appear after firing. In this paper an attempt is made to correlate, for a talc-kaolin-alumina-feldspar mixture resulting in cordierite-sapphirine ceramics after firing to 1250 °C, the resulting elastic properties (Young's modulus), as determined via the impulse excitation technique (IET), with the phase composition, determined via X-ray diffraction (XRD). Moreover, it is shown how the evolution of the phase composition and microstructure is reflected in the temperature dependence of Young's modulus and damping during heating-cooling cycles with maximum temperatures ranging from 1000 to 1250 °C. [ABSTRACT FROM AUTHOR]

A series of (Yb 1-x Gd x) 4 Hf 3 O 12 (x=0, 0.1, 0.2, 0.3 and 0.4) ceramics were synthesized by a solid-state reaction at 1600 °C for 10 h. The phase compositions, microstructure, mechanical properties and thermophysical properties of (Yb 1-x Gd x) 4 Hf 3 O 12 ceramics were investigated. Yb 4 Hf 3 O 12 exhibited a δ-phase structure, while Gd3+ doped Yb 4 Hf 3 O 12 had a defect fluorite structure. The Gd3+ doped Yb 4 Hf 3 O 12 showed higher Vicker's hardness, fracture toughness and Young's modulus compared to Yb 4 Hf 3 O 12. The thermal conductivities of (Yb 1-x Gd x) 4 Hf 3 O 12 ceramics firstly decreased with increasing Gd3+ doping, but subsequently increased with further Gd3+ doping. The (Yb 0.7 Gd 0.3) 4 Hf 3 O 12 exhibited the lowest thermal conductivity of 1.33 W m-1·K-1 at 1200 °C. The thermal expansion coefficients (TECs) of Gd3+ doped Yb 4 Hf 3 O 12 were higher than that of Yb 4 Hf 3 O 12. The (Yb 0.7 Gd 0.3) 4 Hf 3 O 12 showed promising comprehensive properties, suggesting that it could be a potential candidate material for thermal/environmental barrier coatings (T/EBCs). [ABSTRACT FROM AUTHOR]

The present study aims to optimize Cereplast composite materials' mechanical properties, using vine fibers as a reinforcing filler and calcium carbonate as a non-reinforcing filler. The composite samples were prepared in two steps. The first step involves extruding the different mixtures to obtain the granules. A twin-screw rotary cone extruder was used to make different composite formulations. The second step involves manufacturing the standardized specimens using a plastic injection press. Incorporating 20% and 40% vine fibers in the Cereplast matrix increased Young's modulus by 81.5 and 197.9%, respectively. However, the values obtained with calcium carbonate were much lower than those obtained with vine fibers. The tensile strength decreased with an increasing load content due to poor interfacial interaction between the fillers and matrix. The stiffness and brittleness of the composites increased with the loading rate, which reduced the composites' elasticity and led to lower elongation at break. A cross mixture design containing 13 trials has been set up and explored to study the effect of mixing proportions of polymers, vine fiber, and calcium carbonate on the synthesized composites. A three-component constrained mix design can limit the number of experiments to arrive quickly at the optimal mix design. The results of the mixing plane analysis showed that the second-degree model fits well and has good quality. The model correctly described the variation of Young's modulus with the proportions of the mixtures. Thus, increasing the contents of both fillers increases Young's modulus, but vine fibers' effect is more pronounced than calcium carbonate. [ABSTRACT FROM AUTHOR]

This study evaluates the effects of sodium hydroxide (NaOH) treatment on tensile properties of sugar palm 'ijuk' (SPI) fibre-reinforced polymer (FRP) composites, with and without an open hole that acts as a stress concentrator. The NaOH treatment is aimed to improve the interfacial adhesion between SPI fibres and polymer matrix. Composite specimens were prepared using the hand lay-up method, incorporating SPI fibres in various orientations, and featuring a 6 mm diameter hole. Tensile tests were conducted to evaluate the mechanical performance of SPI FRP composite, including ultimate tensile strength, Young's modulus, and elongation at break. The research also compared the properties of SPI to those of synthetic glass fibre in fibre-reinforced polymer composites. The results showed that NaOH treatment significantly improves the fibre-matrix adhesion with 26% increase in tensile strength, leading to enhanced tensile properties in both samples, regardless of hole presence. The 0° orientation provides the highest strength and stiffness when the load is applied in the direction of the fibres. While for the 90° orientation, strength reduces by 14%. The impact of the hole on stress concentration and the subsequent mechanical behaviour of the open-hole specimens is substantial. The findings of this study offer insightful perspectives on the potential use of NaOH-treated SPI fibre in structural and other applications, demonstrating its ability to withstand tensile stresses, even with geometric discontinuities like holes. [ABSTRACT FROM AUTHOR]

The water absorption characteristics of thermoplastic starch (TPS) reveal its ability to interact with and absorb water, influencing its overall performance in various applications. The introduction of aloe vera (AV) gel into the TPS polymeric matrix film has proven beneficial in enhancing tensile strength but a notable deficiency is observed in lowering water absorption percentage. Therefore, this paper aims to reduce the water absorption of the TPS30AV polymer matrix film by utilizing polyethylene (PE) without reducing the tensile strength performance of the TPS30AV film. The TPS30AV film was produced using melt-blending and hot-press techniques. Six samples were presented consisting of a control film (TPS30AV) and TPS30AV film with different concentrations of PE resins (5%, 10%, 20%, 30%, and 40%). The film's performance was assessed by examining its mechanical properties, water absorption, and water solubility. The finding shows that TPS30AV with 40% PE has the highest improvement in water absorption percentage which reduces from 309.86% to 34.16% but a tremendous decrement in tensile strength performance. However, TPS30AV with 10% PE has the highest tensile strength, 9.65 MPa with a 20.99% improvement in water absorption reduction. The properties obtained for TPS30AV10PE were also good in Young's modulus and water solubility percentage. It shows that the film formulated is comparable with previous studies, and improvement has been achieved. As a conclusion, adding PE improved the polymeric structure of TPS30AV and can be used as a biodegradable food-packaging film. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) has gained significant attention as an environmentally friendly biopolymer, but its limited mechanical properties have hindered broader applications. Nanoparticles such as montmorillonite (MMT) offer a promising approach to address this limitation. The intercalation of MMT with polymer chains can significantly impact the mechanical properties of the nanocomposites. Hence, this paper investigated the effect of surface-modified montmorillonite (MMT) nanoparticles on the mechanical properties of polylactic acid (PLA) nanocomposites. The acetylation process of MMT was carried out followed by neutralisation process with NaOH. PLA granules and acetylated-modified MMT were mixed, crushed into granular form, and moulded. The effect of varying concentrations of modified MMTs on the tensile strength, elongation at break, and maximum force of PLA/MMT nanocomposites was evaluated using the ASTM D638 standard. FTIR results showed shifts in peak intensities in regions 2750 cm-1-2810 cm-1 led to changes in the aliphatic and aromatic regions, which confirmed the presence of acetylation. Controlled surface modification improved interfacial interactions and load distribution, enhancing overall mechanical performance. The incorporation of surface-modified MMT in PLA/MMT nanocomposite increased the maximum force, Young's modulus, elongation at breaks and tensile strength. PLA/1wt% MMT and the PLA/7wt% MMT compositions exhibited good mechanical properties. However, the PLA/5 wt% MMT blend is deemed more suitable for food applications, such as disposable cups, plates, and cutleries, due to its lower elongation point. In conclusion, the hydrophilic properties of MMT and the hydrophobic properties of PLA are compatible due to the synergistic effects during surface modification which enhance the overall performance of the nanocomposites. [ABSTRACT FROM AUTHOR]

Epidermal patches utilized for the transduction of biopotentials and biomechanical signals are pivotal in wearable health monitoring. However, the shortcomings, such as inferior conformal ability, deficient adhesion, and motion artifacts, severely impede the bioelectrodes from perceiving stable and superior‐quality physiological signals. Herein, a polymer epidermal patch possessing a spontaneous Janus structure is facilely prepared through itaconic acylhydrazine (IAH) induced gradient polymerization. The solubility discrepancy of the monomers in IAH authorized the Janus structure with distinct adhesion properties on each side. Moreover, the hydrogen bond network constructed by IAH confers the polymer with a high degree of skin compliance, enabling dynamic and stable mechanical properties to withstand complex monitoring environments. By integrating skin‐like softness (Young's modulus ≈0.16 MPa), robust adhesion (35 kPa), and high signal‐to‐noise ratio (32 dB), this epidermal patch displays exceptional elasticity within the physiological activity spectrum, provides swift electrical and mechanical self‐recovery capabilities, and resists interference in dynamic signal monitoring (deformation, compression, humidity, etc.). By demonstrating multifaceted applications for Electrocardiogram recording under diverse disturbances, the epidermal patch profiles a promising noninvasive, enduring wearable bioelectronic interface with immunity to interference. [ABSTRACT FROM AUTHOR]

Polypropylene (PP) is one of the most used polymeric materials worldwide, either as a neat material or as a matrix for composite manufacture employing a molding process. Fused deposition modeling (FDM) 3D printing is an alternative process that offers the potential for manufacturing value‐added products from PP. However, using neat PP for FDM is challenging because 3D‐printed PP warps and shrinks when cooled, and the mechanical properties of PP are poor. PP‐based composites with different fillers (e.g., glass, carbon, and natural fibers) have shown improved properties using FDM processes. An alternative filler for 3D‐printed PP‐based composites is basalt fiber (BF). The objective of this work was to assess the potential and impacts of BF as a filler for BF‐PP composites using FDM processes. PP was compounded with 15, 25, 35, and 45 wt% BF to produce filaments for 3D printing without adding any compatibilizer. Results of rheology studies, morphology, and mechanical and thermal properties of the 3D printed specimens showed that BF positively impacts Young's modulus (E), thermal stability, and dimensional stability of the composite. All composites, when processed at high shear rates (i.e., above 100 1/s), show approximately similar rheological behavior. E is almost doubled in the composite with 25 wt% BF and increased fourfold in the composite with 35 and 45 wt% BF, compared to neat PP. The Izod impact resistance of the formulations containing 35 and 45 wt% BF is ~70% that of neat PP. BF process easily and adequately reinforces PP composites manufactured via FDM. Highlights: Neat PP's poor mechanical properties are improved by adding basalt fiber (BF).Up to 45 wt% BF was used to reinforce PP‐based composites.PP‐BF composites are easier to process via DFM compared to neat PP.BF improves PP‐based composite's thermal and dimensional stability. [ABSTRACT FROM AUTHOR]

Reduced graphene oxide (rGO) was prepared from waste plastic using the two steps pyrolysis method and subsequently functionalized with ethylene diamine (EDA) to develop amino‐functionalized rGO (EDA‐rGO). To make the thermal and mechanical properties more proficient, EDA‐rGO was further incorporated as a nanofiller into a low‐density polyethylene (LDPE) matrix using the melt mixing method followed by hot‐pressing. A variety of analytical methods, such as FT‐IR, XRD, XPS, DSC, TGA, DMA, Raman spectroscopy, and HRTEM, were used to characterize the elements and morphology of rGO and EDA‐rGO. The results showed that the addition of 5 wt% EDA‐rGO to LDPE polymers significantly improved the mechanical and thermal properties, such as storage modulus by 62%, loss modulus by 67%, young's modulus by 123%, tensile strength by 79.83%, respectively. The thermal decomposition temperatures of 5%, 10% and 50% were increased by 14.01, 9.34, and 4.8°C, respectively. This study provides a feasible and ecologically sustainable way of repurposing plastic waste concurrently enhancing the properties of polymer composites. Highlights: Synthesis & functionalization of rGO from waste plastic using EDA.EDA‐rGO used as a nanofiller to fabricate LDPE polymer nanocomposites.EDA‐rGO enhanced the thermal stability of LDPE nanocomposites.The tensile strength & modulus of the LDPE composites are greatly improved.The storage, loss modulus, Tm and Tc enhanced by 62%, 67%, 4.4°C & 2.6°C. [ABSTRACT FROM AUTHOR]

During the last decades, the interest in the development of materials fully or partially biobased has increased. Polyurethanes are extensively used in a wide range of industries because of their versatility. The present work explores the synthesis of partially biobased poly(urethane‐urea) (PUU) composites employing soy‐based polyol (SPO) and cellulose nanocrystals (CNC). The latter were incorporated during the synthesis (in‐situ) or after the synthesis (ex‐situ). The possibility of a technological application as coatings was investigated for the designed materials. Polycaprolactone diol was used as a soft segment due to high functionality of the soy‐based polyol. The physicochemical, thermal and mechanical properties of the prepared matrices were analyzed. Poly(urethane‐urea)s containing up to 20% by weight of biobased polyol showed coating application potentiality. Compared to a polycaprolactone‐based polyurethane, the utilization of the bioprecursor enhanced light absorption in the UV–Vis region. In addition, partially biobased systems showed better mechanical resistance (Young's modulus increased up to 6 times) and hydrophobicity (sweeling decreased from 60 to 8 per cent by weight). Incorporation of cellulose nanocrystals affected primarily the physicochemical and rheological properties of dispersions. Regarding coating properties, nanocrystals utilization complemented the soy‐based polyol improving the performance of the films. Furthermore, the incorporation route affected the dispersions and films properties. Highlights: SPO was incorporated up to 20 per cent by weight in PUU composites.Higher SPO contents improved UV–Vis absorption and tensile strength of films.Films were less hydrophilic as more SPO was incorporated.The CNC‐reinforcement was complementary to the utilization of the SPO.CNC incorporation route affects properties and performance of the coatings. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of multi‐walled carbon nanotubes (MWCNT) addition on the thermomechanical, and electrical responses of unidirectional flax fibers/Elium acrylic modified carbon nanotubes‐based composite. The manufacturing process of these laminated composites involved infusing the nanofillers onto the fibers, ensuring good dispersion of MWCNT within the matrix. Regardless of the rate of incorporated nanotubes, this study revealed a significant deterioration of the mechanical properties in tension and viscoelastic properties of the Elium acrylic resin‐based nanocomposite. The electrical conductivity significantly increased for all nanocomposites and laminated composites. In contrast to the nanocomposite, the unidirectional flax fibers/MWCNT/Elium acrylic composite exhibited a considerable improvement in mechanical properties. An increase in Young's modulus and stress at break of about 27% and 23% respectively, was achieved for the material loaded with 2 wt% of MWCNT. The presence of MWCNT reduces the saturation weight by 5% for the unidirectional composite filled with an amount of 1.5 wt% in MWCNT. Highlights: Improving the electrical properties of nanocomposites and unidirectional fibers (UD) composites.Improving the mechanical properties of Elium/flax/multi‐walled carbon nanotubes (MWCNT) composites.Influence of MWCNTs on the water absorption of UD composites.Influence of MWCNT on the glass transition temperature of nanocomposites.Inhibiting polymerization of MWCNT with Elium. [ABSTRACT FROM AUTHOR]

This paper presents an experimental examination of the compression demeanor of lightweight corrugated core composite (CCC) sandwich panel and corrugated core smart composites (CCSC) sandwich panels subjected to quasi‐static edgewise compression loading. The existence of shape memory alloy (SMA) wires and pre‐strain percentages of SMA are the indicators studied in this article. The fabrication procedure presented and the appraisement of the mechanical properties of the CCC and CCSC sandwich panels are expressed. The core geometry of samples is trapezoid corrugated made of aluminum. The facesheets are four layers of woven glass fiber/ epoxy laminated composite. For evaluation of the efficacy of the presence of SMA wires on mechanical specifications of sandwich panels, three SMA wires with various pre‐strain percentages (0%, 3%, and 6%) are embedded in each composite facesheet. Mechanical properties of all types of CCC and CCSC sandwich panels such as maximum force, critical damage force, specific strength, absorb energy, specific toughness, Young's modulus, and specific stiffness were evaluated. Results showed that the CCC sandwich panel has higher mechanical specifications than the CCSC sandwich panels with 0% and 3% pre‐strain. Also, increasing pre‐strained SMA wires improves all mechanical parameters of CCSC sandwich panels. CCSC sandwich panel with 6% pre‐strain has the highest compression properties than other sandwich panels. Maximum Force, Critical Damage Force, Specific Strength, Absorbed Energy, Specific Toughness, Young's Modulus, and Specific Stiffness of CCSC sandwich panel with 6% pre‐strain are 14.73 kN, 13.6 kN, 9.55 MPa/g, 26.61 kJ, 0.346 MJ/m3g, 4395 MPa and 0.61 kN/mm g, respectively. Highlights: Lightweight CCC sandwich panel and CCSC sandwich panel manufactured.Compression behavior of CCC sandwich panel and CCSC sandwich panel evaluated.Pre‐strained SMA wires improves energy absorption of CCSC sandwich panels.Higher specific toughness was obtained with 6% pre‐strain SMA.Presence of SMA wires with no pre‐strain cannot improve the specific strength. [ABSTRACT FROM AUTHOR]

There has been great interest in developing high‐performance, sustainable and eco‐friendly materials. This study presents an innovative development and research of the mechanical properties of dog bone–reinforced epoxy composites to determine their suitability for biomedical applications. Good surface compatibility for the matrix and reinforcement was the target, complementing the structural compatibility needed for such applications. Hand‐lay open mould technique was used to fabricate the composites with varying weight percentage of dog bone particles (DBPs), and mechanical properties (tensile strength, Young's modulus, percentage elongation and flexural strength) were determined. The results show that the developed composites' mechanical properties were enhanced, and the tensile strength of 21.10 MPa–27.97 MPa, Young's modulus of 1531.00 MPa–1732.90 MPa, ductility of 2.10%–2.60% and flexural strength of 27.53 MPa–35.67 MPa were recorded for the biocomposites. Energy‐dispersive X‐ray spectroscopy (EDS) revealed the main elements' contents of the DBPs as calcium (50.3%), carbon (20.77%) and oxygen (11.76%). Scanning electron microscopy (SEM) examination of the fractured surfaces revealed the homogeneous distribution of the dog bone particulates within the epoxy matrix, which caused the property enhancement. The findings of this research underline the potency of processed animal waste as filler materials. [ABSTRACT FROM AUTHOR]

Electrospinning is an outstanding manufacturing technique for producing nano-micro-scaled fibrous scaffolds comparable to biological tissues. However, the solvents used are normally hazardous for the health and the environment, which compromises the sustainability of the process and the industrial scaling. This novel study compares different machine learning models to predict how green solvents affect the morphology, topography and mechanical properties of gelatin-based scaffolds. Gelatin-based scaffolds were produced with different concentrations of distillate water (dH2O), acetic acid (HAc) and dimethyl sulfoxide (DMSO). 2214 observations, 12 machine learning approaches, including Generalised Linear Models, Generalised Additive Models, Generalised Additive Models for Location, Scale and Shape (GAMLSS), Decision Trees, Random Forest, Support Vector Machine and Artificial Neural Network, and a total of 72 models were developed to predict diameter of the fibres, inter-fibre separation, roughness, ultimate tensile strength, Young's modulus and strain at break. The best GAMLSS models improved the performance of R2 with respect to the popular regression models by 6.868%, and the MAPE was improved by 21.16%. HAc highly influenced the morphology and topography; however, the importance of DMSO was higher in the mechanical properties. The addition of the morphological properties as covariates in the topographic and mechanical models enhanced their understanding. [ABSTRACT FROM AUTHOR]

This paper proposes a new impulse excitation technique using a square plate. First, the functional relationship between the modal frequency of the specimen and the geometrical dimensions and mechanical parameters was established by using the finite element method. Then, the continuous functional relationship derived by a homotopy method allowed the frequency ratios to be related to the thickness-to-length ratio and Poisson's ratio. By measuring the frequency ratios and thickness-to-length ratio, Poisson's ratio could be calculated using this functional relationship. When the density and Poisson's ratio were known, Young's modulus could be identified inversely in conjunction with the finite element analysis. Finally, a comparison test between this method and the traditional impulse excitation technique was designed and implemented, and the results showed that this method has advantages in both testing efficiency and accuracy. The study provides a new idea for system identification, which has important application value and promotion significance. [ABSTRACT FROM AUTHOR]

Sodium‐ion battery (SIB) research benefits from lithium‐ion battery (LIB) studies due to Li and Na thermodynamic similarities. However, underneath these thermodynamic considerations lie kinetics factors leading to distinct Na+ versus Li+ storage mechanisms even within the same electrode materials, which is ascribed to either ionic size variations or diffusion path differences. Herein, the library of such non‐negligible factors is extended by targeting an alloying‐type bismuth anode well known for its high volumetric capacity for both Li+ and Na+ storage, showing that the mechanical property of key reaction intermediates also plays a role in differentiating its Na+ versus Li+ storage mechanisms. Applying spatially and temporally resolved in situ transmission electron microscopy to Li+ and Na+ storage within bismuth, it not only demonstrates the thermodynamic similarity in a step‐wise phase transition but also discloses its kinetic distinctions in morphological and structural integrities determined by Young's modulus of involving reaction intermediates and spatial configuration, which well accounts for the surprisingly observed superior Na+ storage performance of Bi anode compared to the inferior Li+ storage. Findings here highlight the role of reaction intermediates’ mechanical properties in regulating the overall cycling durability of electrode materials, and guide future material engineering toward performance enhancement, particularly for SIBs. [ABSTRACT FROM AUTHOR]

The highly anisotropic crystal structure of β-Ga2O3 gives rise to a variety of crystal planes, among which the (310) plane is a potentially stable close-packed plane for the O sublattice. In this paper, we report the β-Ga2O3 single crystal and substrates with a (310) major plane grown by the spontaneous nucleation technique in the casting method. High-quality crystal growth and substrate processing were confirmed by the 25.67 arc sec full width at half maximum and the 0.25 nm surface roughness. The nanoindentation experiments revealed the (310) substrate's better elastic recovery than that of (100) substrate. The Young's modulus and hardness of (310) substrates were 200 and 7.6 GPa, respectively. The surface barrier height and the Schottky barrier height were 1.25 and 0.92 eV, respectively. First principles calculations identified the (310)-Ga-I plane as the most stable surface configuration of the (310) plane under oxygen-poor condition, with a surface energy density of 1.48 J/m2. The (310) twin boundary formation around the O sublattice has a high energy density of 0.55 J/m2, suggesting its unlikelihood of spontaneous formation. These properties of (310) plane facilitate a high-quality crystal processing and epitaxial growth, thus endowing potential applications in high-quality power devices. Furthermore, the growth and fabrication of the (310) plane provide a route toward understanding the properties of β-Ga2O3 and advancing the growth techniques of oxide crystals. [ABSTRACT FROM AUTHOR]

Conductive hydrogels have been widely used in soft robotics, as well as skin-attached and implantable bioelectronic devices. Among the candidates of conductive fillers, conductive polymers have become popular due to their intrinsic conductivity, high biocompatibility, and mechanical flexibility. However, it is still a challenge to construct conductive polymer-incorporated hydrogels with a good performance using a facile method. Herein, we present a simple method for the one-pot preparation of conductive polymer-incorporated hydrogels involving rapid photocuring of the hydrogel template followed by slow in situ polymerization of pyrrole. Due to the use of a milder oxidant, hydrogen peroxide, for polypyrrole synthesis, the photocuring of the hydrogel template and the growing of polypyrrole proceeded in an orderly manner, making it possible to prepare conductive polymer-incorporated hydrogels in one pot. The preparation process is facile and extensible. Moreover, the obtained hydrogels exhibit a series of properties suitable for biomedical strain sensors, including good conductivity (2.49 mS/cm), high stretchability (>200%), and a low Young's modulus (~30 kPa) that is compatible with human skin. [ABSTRACT FROM AUTHOR]

The brittleness index, as the most important parameter for brittleness evaluation, directly affects the compressibility of unconventional reservoirs. Currently, there is no unified calculation method for the brittleness index. This article uses a three-axis rock mechanics servo testing system to test the rock mechanics parameters of shale oil reservoirs in Block Y of the Ordos Basin and uses an X'Pert PRO X-ray diffractometer to test the rock mineral composition. The average volume fraction of quartz minerals, feldspar, and clay minerals in 36 samples of Block Y was tested to be 22.6%, 51.6%, and 18%, respectively. Calcite, dolomite, and pyrite are only present in a few samples. When the confining pressure is 30 MPa, the elastic modulus of the Chang 7 shale in this block is 14.72–34.58 GPa, with an average value of 23.77 GPa; The Poisson's ratio ranges from 0.106 to 0.288, with an average of 0.182; The differential stress ranges from 100.8 to 260.1 MPa, with an average of 164.36 MPa; The peak strain ranges from 0.57 to 1.21, with an average of 0.91. This article compares several mainstream brittle index evaluation methods and identifies the most suitable brittle index evaluation method for Block Y. Using the Jarvie mineral composition method to calculate the brittleness index 1 (MBI), the average value of 36 experimental results is 0.5393. Using the Rickman normalized Young's modulus and Poisson's ratio average value to calculate the brittleness index 2 (EBI), the average value of 36 experimental results is 0.5204. Based on the stress-strain curve and energy method, a model for brittleness index 3 (DBI) is established, and the average value of 36 experimental results is 0.5306. The trend of the brittleness index calculated by the three methods is consistent, indicating the feasibility of the newly established brittleness evaluation method. From the perspectives of mineral composition, rock mechanics parameters, and energy, establishing a brittleness evaluation method for shale oil reservoirs and studying its evaluation method is of great significance for sweet spot prediction in reservoir engineering, providing theoretical support for the selection of fractured intervals in the Chang 7 shale oil reservoir in Block Y of the Ordos Basin. [ABSTRACT FROM AUTHOR]

The yield strength and Young's modulus of lattice structures are essential mechanical parameters that influence the utilization of materials in the aerospace and medical fields. Currently, accurately determining the Young's modulus and yield strength of lattice structures often requires conduction of a large number of experiments for prediction and validation purposes. To save time and effort to accurately predict the material yield strength and Young's modulus, based on the existing experimental data, finite element analysis is employed to expand the dataset. An artificial neural network algorithm is then used to establish a relationship model between the topology of the lattice structure and Young's modulus (the yield strength), which is analyzed and verified. The Gibson–Ashby model analysis indicates that different lattice structures can be classified into two main deformation forms. To obtain an artificial neural network model that can accurately predict different lattice structures and be deployed in the prediction of BCC-FCC lattice structures, the artificial network model is further optimized and validated. Concurrently, the topology of disparate lattice structures gives rise to a certain discrete form of their dominant deformation, which consequently affects the neural network prediction. In conclusion, the prediction of Young's modulus and yield strength of lattice structures using artificial neural networks is a feasible approach that can contribute to the development of lattice structures in the aerospace and medical fields. [ABSTRACT FROM AUTHOR]

Persistent luminescent materials are those which can store an amount of energy locally and release it slowly in the form of light. In this work, persistent luminescent nanoparticles (PLNPs) were synthesized and incorporated into polypropylene (PP) filaments at various loading percentages. We investigated the optical properties of both the as-prepared PLNPs and the PLNP-loaded filaments, focusing on any changes resulting from the integration into the filaments. Specifically, visible and near-infrared spectroscopy were used to analyze the emission, excitation, and persistent luminescence of the PLNPs and PLNP-loaded filaments. The tensile properties of the extruded filaments were also investigated through breaking tenacity, elongation at break, Young's modulus, and secant modulus. All PLNP-loaded filaments were shown to exhibit persistent luminescence when exposed to ultraviolet light. While there were no significant changes in the elongation at break or Young's modulus for the loading percentages tested, there was a slight increase in breaking tenacity and a decrease in the secant modulus. Finally, the filaments were shown to maintain their optical properties and persistent luminescence even after abrasion testing used to simulate the normal wear and tear that fabric experiences during use. These results show that PLNPs can be successfully incorporated into filaments which can be used in fabrics and will maintain the persistent luminescent properties. [ABSTRACT FROM AUTHOR]

An understanding of the mechanical behavior of polymeric materials is crucial for making advancements in the applications and efficiency of nanocomposites, and encompasses their service life, load resistance, and overall reliability. The present study focused on the prediction of the mechanical behavior of biopolymeric nanocomposites with nano-clays as the nanoadditives, using a new modeling and simulation method based on Comsol Multiphysics software 6.1. This modeling considered the complex case of flake-shaped nano-clay additives that could form aggregates along the polymeric matrix, varying the nanoadditive thickness, and consequently affecting the resulting mechanical properties of the polymeric nanocomposite. The polymeric matrix investigated was biopolyamide 11 (BIOPA11). Several BIOPA11 samples reinforced with three different contents of nano-clays (0, 3, and 10 wt%), and with three different nano-clay dispersion grades (employing three different extrusion screw configurations) were obtained by the compounding extrusion process. The mechanical behavior of these samples was studied by the experimental tensile test. The experimental results indicate an enhancement of Young's modulus as the nano-clay content was increased from 0 to 10 wt% for the same dispersion grades. In addition, the Young's modulus value increased when the dispersion rate of the nano-clays was improved, showing the highest increase of around 93% for the nanocomposite with 10 wt% nano-clay. A comparison of the modeled mechanical properties and the experimental measurements values was performed to validate the modeling results. The simulated results fit well with the experimental values of Young's modulus. [ABSTRACT FROM AUTHOR]

Alginate hydrogels possess properties analogous to those of the extracellular matrix (ECM). Thus, their mechanical behavior approximates soft tissue, which makes them desirable for the production of tissue-equivalent soft deformable structures. This study aims to determine the synthesis-structure-property relationship for alginate hydrogel with the Young's modulus in the range of 10°~101 kPa, mimicking to that of human lung tissue. Hydrogels, a 3D polymer network embedded in a water-rich environment. Homogeneous alginate hydrogels are synthesized by a direct mixture of sodium alginate and CaCO3, followed by the addition of D-glucono-δ-lactone (GDL) to initiate in-situ Ca2+ release and gelation. The influence of alginate concentration and molar ratio of the constituent calcium ion to carboxyl group from alginate monomer are evaluated while the Young's modulus of the hydrogel is carefully controlled within the desired range. FTIR and SEM are used to characterize the influence of synthesis parameters at the molecular and microstructure levels. Tension and compression testing are performed to determine the Young's modulus of the material. Empirical relations are established between synthesis parameters and the mechanical property. The result of the study will be subsequently used to guide the additive manufacturing of soft deformable structures based on alginate hydrogels. [ABSTRACT FROM AUTHOR]

Bacterial cellulose (BC) is a broadly utilized natural nanofiber produced by microbial fermentation, but its high-cost and low-yield production and limited function still hinder its application. Here, we used the spraying-assisted biosynthesis method to introduce biomass nanofibers along with the nutrient media to the fermenting BC. Biomass nanofibers could be cellulose, chitosan, and others. They entangled with BC nanofibers via intermolecular interactions, including hydrogen binding and electrostatic adsorption, to form uniform BC composites. The BC composites achieved an enhanced yield of ~140 wt% compared with pure BC and displayed similar excellent mechanical properties (Young's moduli = 0.9–1.4 MPa for wet films and =~6500 MPa for dried films). BC composites also had similar high crystallinity and thermal stability to pure BC. The functional groups of biomasses endowed BC composite additional functions such as antibacterial and dye-adsorption capabilities. Moreover, a high yield and functionalization could be realized simultaneously by feeding functional cellulose nanofibers. This method provides a facile way to produce BC composites with low cost, high yield, and multiple functions. [ABSTRACT FROM AUTHOR]

This study explores lignin-retaining transparent wood biocomposite production through a lignin-modification process coupled with epoxy resin. The wood's biopolymer structure, which includes cellulose, hemicellulose, and lignin, is reinforced with the resin through impregnation. This impregnation process involves filling the voids and pores within the wood structure with resin. Once the resin cures, it forms a strong bond with the wood fibers, effectively reinforcing the biopolymer matrix and enhancing the mechanical properties of the resulting biocomposite material. This synergy between the natural biopolymer structure of wood and the synthetic resin impregnation is crucial for achieving the desired optical transparency and mechanical performance in transparent wood. Investigating three distinct wood species allows a comprehensive understanding of the relationship between natural and transparent wood biocomposite properties. The findings unveil promising results, such as remarkable light transmittance (up to 95%) for Aspen transparent wood. Moreover, transparent wood sourced from White Spruce demonstrates excellent stiffness (E = 2450 MPa), surpassing the resin's Young's modulus. Also, the resin impregnation enhanced the thermal stability of natural wood. Conversely, transparent wood originating from Larch showcases superior impact resistance. These results reveal a clear correlation between wood characteristics such as density, anatomy, and mechanical properties, and the resulting properties of the transparent wood. [ABSTRACT FROM AUTHOR]

Collagen nanofibrous materials have become integral to tissue engineering due to their exceptional properties and biocompatibility. Dehydrothermal crosslinking (DHT) enhances stability and maintains structural integrity without the formation of toxic residues. The study involved the crosslinking of electrospun collagen, applying DHT with access to air and under vacuum conditions. Various DHT exposure times of up to 72 h were applied to examine the time dependance of the DHT process. The DHT crosslinked collagen was subsequently chemically crosslinked using carbodiimides. The material crosslinked in this way evinced elevated Young's modulus values and ultimate tensile strength values, a lower swelling rate and lower shrinkage ratio during crosslinking, and a higher degree of resistance to degradation than the material crosslinked solely with DHT or carbodiimides. It was shown that the crosslinking mechanism using DHT occupies different binding sites than those using chemical crosslinking. Access to air for 12 h or less did not exert a significant impact on the material properties compared to DHT under vacuum conditions. However, concerning longer exposure times, it was determined that access to air results in the deterioration of the properties of the material and that reactions take place that occupy the free bonding sites, which subsequently reduces the effectiveness of chemical crosslinking using carbodiimides. [ABSTRACT FROM AUTHOR]

The tensile characteristics of a novel TWARMAT hybrid fabric with a weight of 600 g/m2, comprising aramid and E-glass fibers were assessed. Additionally, a conventional 205-g/m2 plain glass and 160-g/m2 plain carbon fiber fabrics were also tested for comparison. The results obtained reveal that TWARMAT exhibited superior stiffness and density ratios. To confirm these experimental results, the rule of mixtures was utilized. The close agreement between the two sets of data, with mean relative errors of 5.5 and 1.05% for Young's modulus and density respectively, confirms the reliability of the methods applied. [ABSTRACT FROM AUTHOR]

Lightweight, high-strength, conductive carbon nanocomposites are widely used in axial moving systems, and the primary parametric resonance and primary resonance due to variable axial velocity and tension are quite disturbing when they work in complex electromagnetic environments. In this paper, a theoretical model for predicting Young's modulus and electrical conductivity of graphene nanocomposites is developed by combining equivalent medium theory, shear-leg theory, and Mori–Tanaka theory. The magnetoelastic vibration equations of axially moving graphene nanocomposite current-carrying beam with variable speed and axial force are then derived and solved analytically and numerically. The amplitude-frequency response equations are derived to describe the parametric resonance of the nanocomposite beam with different graphene volume concentrations. The coupled effect of graphene fillers, electric–magnetic field, and external citation on the system's primary parametric resonance are deeply investigated. The results showed that the concentration of graphene filler could significantly affect the amplitude response of the system by controlling Young's modulus and electrical conductivity of the nanocomposite. It can provide a theoretical basis for structure design and vibration control in engineering applications. [ABSTRACT FROM AUTHOR]