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Entropy stabilized oxide of MgNiCoCuZnO5, also known as J14, is a material of active research interest due to a high degree of lattice distortion and tunability. Lattice distortion in J14 plays a crucial role in understanding the elastic constants and lattice thermal conductivity within the single-phase crystal. In this work, a neuroevolution machine learning potential (NEP) is developed for J14, and its accuracy has been compared to density functional theory calculations. The training errors for energy, force, and virial are 5.60 meV/atom, 97.90 meV/Å, and 45.67 meV/atom, respectively. Employing NEP potential, lattice distortion, and elastic constants is studied up to 900 K. In agreement with experimental findings, this study shows that the average lattice distortion of oxygen atoms is relatively higher than that of all transition metals in entropy-stabilized oxide. The observed distortion saturation in the J14 arises from the competing effects of minimum site distortion, which increases with increasing temperature due to enhanced thermal vibrations, and maximum site distortion, which decreases with increasing temperature. Furthermore, a series of molecular dynamics simulations up to 900 K are performed to study the stress–strain behavior. The elastic constants, bulk modulus, and ultimate tensile strength obtained from these simulations indicate a linear decrease in these properties with temperature, as J14 becomes softer owing to thermal effects. Finally, to gain some insight into thermal transport in these materials, with the so-developed NEP potential, and using non-equilibrium molecular dynamics simulations, we study the lattice thermal conductivity (κ) of the ternary compound MgNiO2 as a function of temperature. It is found that κ decreases from 4.25 W m − 1 K − 1 at room temperature to 3.5 W m − 1 K − 1 at 900 K. This suppression is attributed to the stronger scattering of low-frequency modes at higher temperatures. [ABSTRACT FROM AUTHOR]

Entropy stabilized oxide of MgNiCoCuZnO5, also known as J14, is a material of active research interest due to a high degree of lattice distortion and tunability. Lattice distortion in J14 plays a crucial role in understanding the elastic constants and lattice thermal conductivity within the single-phase crystal. In this work, a neuroevolution machine learning potential (NEP) is developed for J14, and its accuracy has been compared to density functional theory calculations. The training errors for energy, force, and virial are 5.60 meV/atom, 97.90 meV/Å, and 45.67 meV/atom, respectively. Employing NEP potential, lattice distortion, and elastic constants is studied up to 900 K. In agreement with experimental findings, this study shows that the average lattice distortion of oxygen atoms is relatively higher than that of all transition metals in entropy-stabilized oxide. The observed distortion saturation in the J14 arises from the competing effects of minimum site distortion, which increases with increasing temperature due to enhanced thermal vibrations, and maximum site distortion, which decreases with increasing temperature. Furthermore, a series of molecular dynamics simulations up to 900 K are performed to study the stress–strain behavior. The elastic constants, bulk modulus, and ultimate tensile strength obtained from these simulations indicate a linear decrease in these properties with temperature, as J14 becomes softer owing to thermal effects. Finally, to gain some insight into thermal transport in these materials, with the so-developed NEP potential, and using non-equilibrium molecular dynamics simulations, we study the lattice thermal conductivity (κ) of the ternary compound MgNiO2 as a function of temperature. It is found that κ decreases from 4.25 W m − 1 K − 1 at room temperature to 3.5 W m − 1 K − 1 at 900 K. This suppression is attributed to the stronger scattering of low-frequency modes at higher temperatures. [ABSTRACT FROM AUTHOR]

Grafting nanomaterials on the carbon fiber (CF) surface is considered an effective strategy for enhancing the interfacial properties of CF-reinforced polymer composites (CFRPs). However, the mechanical properties of the CFs are often compromised during treatment. A new method for in situ growing silver nanoparticles (AgNPs) on the CF surface is proposed in this study. The CFs are first immersed in a low-viscosity silver nitrate solution to form a thin liquid film on the surface. Subsequently, using the abundant active particles in the plasma, the silver ions are reduced to silver atoms and grown into AgNPs on the CF surface. The tensile strength of CF@Ag was 38.74% greater than that of untreated CF, potentially due to the reparative action of AgNPs on defects in CF. The CF showed an evident improvement in surface wettability because of the AgNPs. Furthermore, the interfacial properties were noticeably improved, with the interfacial shear strength of CF@Ag increasing to 91.59 MPa, which was about twice that of pristine CF. Thus, the mechanical properties of composites are significantly improved (flexural strength increased by 190.74%). This study presents a non-destructive and convenient method for growing nanoparticles onto CF to establish a robust interface in CFRPs. [ABSTRACT FROM AUTHOR]

The increasing electromagnetic pollution due to the widespread use of electronic devices has drawn attention to the development of high-efficiency electromagnetic wave absorption materials. In this study, polypropylene (PP)/Ni composite materials were prepared using the fused deposition modeling method, with PP as the matrix. The mechanical and absorption properties were investigated, showing that the PP-based materials exhibited good mechanical performance with a tensile strength of 25.3 MPa and an elongation at break of 32.1%. At a Ni content of 50% and a thickness of 1.9 mm, the composite material showed absorption properties of −24.31 dB and 5.6 GHz. The absorption bandwidth covered the entire X and Ku bands (6.4–18 GHz) with adjustable thickness ranging from 1.5 to 4 mm. The combination of excellent absorption and mechanical properties makes these materials promising for the fabrication of complex absorber devices. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Fibrin sealants are routinely used for intra-articular surgical fixation of cartilage fragments and implants. However, the mechanical properties of fibrin sealants in the context of cartilage repair are unknown. The purpose of this study was to characterize the adhesive and frictional properties of fibrin sealants using an ex vivo model. DESIGN: Native bovine cartilage-bone composites were assembled with a single application of Tisseel or Vistaseal. Composites were tested in tension and lap shear. In addition, the coefficient of friction (COF) was measured in a native cartilage annulus model alone and with minced cartilage. Finally, the effect of a double application of fibrin sealant was evaluated. RESULTS: There were no significant differences in tensile modulus, ultimate tensile strength (UTS), shear modulus, or ultimate shear strength (USS) between the 2 fibrin sealants. Both fibrin sealants demonstrated a UTS and USS of

OBJECTIVE: The purpose of this study was to determine the in vitro effects of a single exposure of bupivacaine on the mechanical properties of bovine cartilage explants at 3 weeks. DESIGN: Femoral condyle articular cartilage explants were aseptically harvested from juvenile bovine stifle joints before being exposed to chondrogenic medium containing 0.50% (wt/vol) bupivacaine, 0.25% (wt/vol) bupivacaine, or no medication (control) for 1 hour. Explants were then washed and maintained in culture in vitro for 3 weeks before testing. Cell viability, tensile and compressive mechanical properties, histological properties, and biochemical properties were then assessed. RESULTS: Explants exhibited a dose-dependent decrease in mean tensile Youngs modulus with increasing bupivacaine concentration (9.86 MPa in the controls, 6.48 MPa in the 0.25% bupivacaine group [P = 0.048], and 4.72 MPa in the 0.50% bupivacaine group [P = 0.005]). Consistent with these results, collagen content and collagen crosslinking decreased with bupivacaine exposure as measured by mass spectrometry. Compressive properties of the explants were unaffected by bupivacaine exposure. Explants also exhibited a trend toward dose-dependent decreases in viability (51.2% for the controls, 47.3% for the 0.25% bupivacaine-exposed group, and 37.0% for the 0.50% bupivacaine-exposed group [P = 0.072]). CONCLUSIONS: Three weeks after 1-hour bupivacaine exposure, the tensile properties of bovine cartilage explants were significantly decreased, while the compressive properties remained unaffected. These decreases in tensile properties corresponded with reductions in collagen content and crosslinking of collagen fibers. Physicians should be judicious regarding the intra-articular administration of bupivacaine in native joints.

Amorphous solids are known to fail catastrophically via fracture, and cavitation at nano-metric scales is known to play a significant role in such a failure process. Micro-alloying via inclusions is often used as a means to increase the fracture toughness of amorphous solids. Modeling such inclusions as randomly pinned particles that only move affinely and do not participate in plastic relaxations, we study how the pinning influences the process of cavitation-driven fracture in an amorphous solid. Using extensive numerical simulations and probing in the athermal quasistatic limit, we show that just by pinning a very small fraction of particles, the tensile strength is increased, and also the cavitation is delayed. Furthermore, the cavitation that is expected to be spatially heterogeneous becomes spatially homogeneous by forming a large number of small cavities instead of a dominant cavity. The observed behavior is rationalized in terms of screening of plastic activity via the pinning centers, characterized by a screening length extracted from the plastic-eigenmodes. [ABSTRACT FROM AUTHOR]

High-entropy alloys possess significant potential for material applications in demanding structural components subjected to extreme conditions. Through experimental investigations, we have validated that the CoCrFeNiAl0.1Ti0.05 high-entropy alloy, which was fabricated using a cold rolling and annealing process, exhibits an excellent balance of strength and ductility at 77 K. Specifically, it demonstrates a yield strength of 575 MPa, a tensile strength of 1145 MPa, and a ductility of 55%. This enhanced performance can be attributed to the altered deformation mechanism at low temperatures, leading to the multiplications of stacking faults and twins. Additionally, the introduction of small quantities of aluminum and titanium results in the formation of precipitated phases within the alloy matrix. The synergistic influence of these two factors contributes to the augmentation of cryogenic plasticity in the alloy. [ABSTRACT FROM AUTHOR]

This study investigated the effect of erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser conditioning on dentin bond strength and nanoleakage of different universal and self-etch adhesives. A total of 84 intact human third molar teeth were cut at the dentin level, and half of them were laser conditioned. The specimens were divided into three groups; two different universal resins and one self-etch adhesive resin were applied and composite resin restorations were created. For the microtensile bond strength (pTBS) test, 20 microspecimens were prepared from the laser and control group of each adhesive (n = 20) and tested with a universal device. For nanoleakage observation, 10 specimens were prepared from each group (n = 10) and stored in silver nitrate solution, and then the amount of nanoleakage was analyzed by field emission scanning electron microscopy (FESEM). Data were analyzed with two-way ANOVA, Tukey's honestly significant difference, and chi-square tests. The mean dentin bond strength of all adhesives in the laser groups was found to be statistically significantly lower than those of the control groups (P < .05). No difference was found between the mean bond strength of the adhesives in the laser and control groups (P > .05). Higher nanoleakage was observed in all adhesives in the laser groups compared to the control groups (P < .05). Irradiation of the dentin surface with Er,Cr:YSGG could adversely affect the piTBS and nanoleakage, likely by affecting the structure of the hybrid layer. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the effect of 2% chlorhexidine (CHX) on an etch-and rinse adhesive to dentin. Caries-free molars were selected and processed to expose a flat dentin surface. The specimens were bonded with a composite resin by an etch-and-rinse adhesive, which was pretreated with 2% CHX for 0, 15, 30, 45, and 60 seconds. The microtensile bond strength (MTBS) was evaluated before and after thermocycling. No significant differences were observed between groups before thermocycling. The 60-second CHX-pretreated group showed a significantly greater MTBS than the control group after thermocycling. The 2% CHX pretreatment could improve the bonding strength of the etch-and-rinse adhesive and slow down the aging progress of the bonding interface. [ABSTRACT FROM AUTHOR]

The field of hybrid engineered living materials seeks to pair living organisms with synthetic materials to generate biocomposite materials with augmented function since living systems can provide highly-programmable and complex behavior. Engineered living materials have typically been fabricated using techniques in benign aqueous environments, limiting their application. In this work, biocomposite fabrication is demonstrated in which spores from polymer-degrading bacteria are incorporated into a thermoplastic polyurethane using high-temperature melt extrusion. Bacteria are engineered using adaptive laboratory evolution to improve their heat tolerance to ensure nearly complete cell survivability during manufacturing at 135 °C. Furthermore, the overall tensile properties of spore-filled thermoplastic polyurethanes are substantially improved, resulting in a significant improvement in toughness. The biocomposites facilitate disintegration in compost in the absence of a microbe-rich environment. Finally, embedded spores demonstrate a rationally programmed function, expressing green fluorescent protein. This research provides a scalable method to fabricate advanced biocomposite materials in industrially-compatible processes.

The AA2219 is an Al-Cu alloy with widespread engineering applications. The sheet parts of this alloy are produced by metal forming and are subjected to age hardening (e.g., T6 temper) for strengthening. The cold work in metal forming affects the ageing behavior of alloy and hence the resulting mechanical properties. In this research, a novel forming technique namely Incremental Forming with three different forming-ageing routes is employed to produce age-hardened AA2219 parts. The resulting microstructure evolution, mechanical properties, and residual stresses are examined. The results reveal that forming imposed cold work (35% plastic strain) enhances the sheet strength and hardness to a certain extent, which can be further enhanced by opting an optimum forming-ageing route. Similarly, the residual stresses also show sensitivity to the forming-ageing route opted. Based upon extensive analysis of the experimental results, it is concluded that the [O-IF-ST-T6] route is the most appropriate route for producing age-hardened parts with high strength, hardness and ductility, and low residual stresses (where O, IF, ST, and T6 represent parent, incremental forming, solution treatment and T6 ageing, respectively). This route is found to offer a gain of 238% in the tensile yield strength, 151% in the ultimate tensile strength, and 200% in the hardness with respect to the parent metal. Further, from several correlations drawn between mechanical properties and microstructural quantities, namely grain size, and precipitate's size and density, strengthening mechanism is revealed for the reported gains. [ABSTRACT FROM AUTHOR]

Binders used in binder jetting often pose health and environmental risks during processing and post processing operations. The print-heads which are used to deposit binder selectively on the feedstock are prone to clogging, despite the trend of print-heads being highly customised to suit different kinds of binders. These factors often hide the advantages of binder jetting as an additive manufacturing process, especially its scalability and its faster printing rates in comparison to powder bed fusion methods. The work presented here takes a step back and focuses on the development of an aqueous, polyvinyl alcohol (PVA)-based liquid binder that is easy to manufacture and store, safe to handle, and can be reliably jetted to print parts. The feedstock considered was Inconel 718, a nickel-based super alloy which can be effectively processed by binder jetting without niobium segregation. PVA was added to the Inconel 718 powder in dry, granular form to manufacture a modified feedstock. The study also investigated the role of molecular weight of the PVA used, sintering environments and post-processing methods like hot isostatic pressing (HIP) on process responses like part densification, tensile strength, and hardness. Three different types of PVA were chosen which had molecular weights 10,000 g/mol (low molecular weight or LMW), 26,000 g/mol (medium molecular weight or MMW), and 84,000 g/mol (high molecular weight or HMW). The compatibility of the liquid, aqueous PVA-based binders with virgin Inconel 718 was examined by measuring the contact angle. The liquid, aqueous binder having MMW PVA reported better wetting with the Inconel 718 powder with a wetting angle of 26.6 which was lower than the wetting angle of 42.4°, seen in case of a commercial resin-based binder. The green strength reported by the MMW PVA liquid binder was 220 kPa which was higher than the other two PVA-based liquid binders. Green parts, upon successful printing, were sintered at 1260 °C. It was observed that a part printed using MMW PVA had a densification of 96.16% when sintered in 99.98% by volume argon gas, which increased to 98.96% after undergoing HIP. The same part reported a densification of 88.69% when sintered in a 95% by volume N2 and 5% by volume H2 gaseous environment, which was later attributed to the uptake of nitrogen by the chromium present in Inconel 718, which prevented necking between particles. Tensile specimens printed using MMW PVA, sintered in a 99.98% argon environment, showed the highest ultimate tensile strength of 220 MPa, which increased to 1010 MPa after the HIP process, which can be compared to commercially available Inconel 718. [ABSTRACT FROM AUTHOR]

Hydrogen energy is becoming increasingly important worldwide. Due to cost-effectiveness, ferritic and martensitic steels have been commonly used for hydrogen services such as pipelines and storage tanks. However, these steels are prone to hydrogen embrittlement (HE), which causes ductility loss without affecting yield and ultimate tensile strength. Assessing hydrogen compatibility in terms of strength, especially under localized stress, which might correlate with the relative notch tensile strength (RNTS) is necessary. This study aims to establish a procedure to determine the RNTS through the small punch test (SPT) using U-shaped notch specimens in high-pressure environments at room temperature. The notch tensile strength (NTS) was calculated through simulation from the maximum equivalent stress (σ max) at corresponding fracture displacement (δ f) using the load-displacement curve obtained by SPT under each test condition. The combined experiment and numerical approach effectively determined the RNTS, confirming the SPT of notched specimens in screening the HE susceptibility of the steels. • A novel RNTS determination for hydrogen compatibility screening of ferritic steels. • A 0.2 mm depth U-shaped notch specimen as suitable geometry for NTS determination. • δ f was an effective parameter to represent the HE effect for NTS calculation. • A combined approach of SPT and simulation effectively determined the RNTS. • A strength-based HE susceptibility evaluation using notched SP specimens. [ABSTRACT FROM AUTHOR]

In this study, carbon fiber paper (CFP) was prepared by adding carboxyl nitrile latex (XNBRL) and phenolic resin (PF) into the carbon fibers suspension instead of the immersion method. It was found that XNBRL and PF adsorbed and flocculated on the surface of the carbon fibers as cationic agent was used. And with the increase of XNBRL addition, the retention rate of the pulp and the size of the flocs gradually increased. Due to the low residual carbon rate of XNBRL, most of it was decomposed into small molecular gases during carbonization, with the increase of XNBRL addition, the CFP became fluffy gradually, and its thickness, resistivity and air permeability increased, while the density and tensile strength decreased, and the basis weight was basically unchanged. Owing to the high residual carbon rate of PF, the basis weight, density and tensile strength of the CFP gradually increased with the increase of PF addition, while the thickness, resistivity and air permeability gradually decreased. Therefore, XNBRL could promote the retention of PF during paper forming, when the XNBRL dosage was 60 wt% and PF was 300 wt%, the basis weight of CFP was 74.55 g/m2, the thickness was 0.22 mm, the tensile strength was 10.85 MPa, the resistivity was 0.0284 Ω·cm, and the air permeability was 2005.34 mL·mm/ (cm2·h·mmHg). • Carbon fiber paper was prepared using carboxyl nitrile latex and phenolic resin in-pulp addition method. • The retention rate of the pulp and the flocs size gradually increased with the increase of carboxyl nitrile latex content. • Carbon fiber paper exhibited excellent comprehensive performance. [ABSTRACT FROM AUTHOR]

To enhance the load-bearing capacity of sapphire optical fiber (SOF) in extreme environments, this study prepared SOF/(BN/SiBCN) n by optimizing the nanostructure through increased deposition temperature of BN using alternating chemical vapor deposition. Simulation results indicated an inverse correlation between the leakage loss of SOF/BN/SiBCN and BN thickness; at room temperature, the tendency for coating cracking along the radial direction of SOF/BN/SiBCN is positively correlated with BN thickness, whereas this trend reverses at 1500 °C. Mechanical testing revealed that the tensile strength of SOF/BN/SiBCN is inversely correlated with the tendency for interlayer cracking, aligning with the findings from residual stress simulations; under an air environment at 1500 °C, SOF/(BN/SiBCN) 2 exhibited the highest tensile strength, indicating that the layered matrix design effectively mitigates the risk of BN oxidation by creating barrier layers. Optical test demonstrated that the BN coating functions as a total reflection layer to suppress the scattering of optical signals on the sapphire optical fiber surface. In conclusion, the coating design of SOF/(BN/SiBCN) n could meet the material requirements for sapphire optical fiber sensors in extreme environments. [ABSTRACT FROM AUTHOR]

The combination of aromatic and aliphatic structures can endow polyurea with distinct performance advantages. A one‐step feeding method is used to synthesize linear hybrid aliphatic/aromatic copolyureas by varying the ratio of m‐phenylenediamine (MPD) and polyoxypropylenediamine (D2000) reacting with 4,4′‐diphenylmethane diisocyanate (MDI). Real‐time Fourier‐transform infrared spectrometer monitoring reveals that D2000 exhibits higher reactivity than MPD. Consequently, in the MDI/MPD/D2000 system, D2000 initially reacts with MDI to form an isocyanate‐terminated prepolymer, which subsequently reacts with MPD. Compared with the two‐step feeding method, this approach successfully eliminates biuret formation and enhances tensile strength. Additionally, decreasing the molar ratio of D2000 to MPD (λm) reduces the size and degree of microphase separation in the polyurea by increasing the ordered hydrogen bonding and benzene conjugation, leading to an increase in tensile strength. Specifically, as λm decreases from 70 mol% to 30 mol%, the degree of microphase separation decreases from 0.47 to 0.2, causing the tensile strength to rise from 28 to 48 MPa. Further reducing λm to 30 mol% decreases the degree of microphase separation to 0.16, resulting in an increase in tensile strength to 78 MPa. [ABSTRACT FROM AUTHOR]

To regulate the comprehensive performance of ethylene‐propylene‐diene monomer (EPDM)‐based oil‐absorbing expandable rubber, a series of irradiated α‐olefin‐EPDM7001 rubbers (EOR7001‐X‐Y) are prepared. The influence of the carbon chain length and content of α‐olefins on the structure and properties of the rubber is systematically investigated. Results show that EOR7001‐X‐Y possesses a cross‐linked network structure, and its gel fraction decreases gradually with the increase in carbon chain length and content of α‐olefins. The incorporation of α‐octadecene successfully creates micro‐nanoscale porous structures within the rubber matrix, providing favorable conditions for oil absorption. The introduction of α‐olefins and changes in irradiation dose do not significantly affect the thermal stability of EPDM7001 rubber. The tensile strength slightly reduces, while elongation at break significantly increases, improving the deformation capability. EOR7001‐18‐20 demonstrates exceptional resistance to aging and withstands external forces even after oil absorption. This study supports the development of high‐performance oil‐absorbing expandable rubber. [ABSTRACT FROM AUTHOR]

The development of eco-friendly materials is a challenging one in the research field. Natural fibers are more accessible, biodegradable, inexpensive, and less dense. They offer fewer health risks and are eco-friendly compared to synthetic fibers. Natural fiber-reinforced polymer composites are new, eco-friendly materials with excellent mechanical and practical applications. Adding biofillers to composites improves strength and will replace synthetic materials. Utilizing cellulose as a filler for a natural starch matrix is an effective way to reduce the environmental impact of non-biodegradable materials. This study covers the influence of natural Borassus flabellifer flower microcrystalline cellulose (BFF MCC) fillers on banana fiber-reinforced polymer matrix composites. Fourier-transform infrared spectroscopic peaks at 2357, 1730, and 1245 cm-1 were absent. This indicates that the amorphous proportion of banana fiber mat/BFF MCC-reinforced hybrid composites decreased. At 1% BFF MCC, thermogravimetric examination revealed an increase in the peak temperature of maximum degradation (389.6 °C). The hybrid banana composite's tensile strength (31.36 ± 4.39 to 39.83 ± 3.07 MPa) and flexural strength (71.05 ± 2.66 to 82.4 ± 1.66 MPa) were also improved after adding 3% BFF MCC as filler material. The primary objective is to evaluate the suitability of fiber-reinforced hybrid polymers with natural fillers for future engineering applications such as automotive parts, construction materials, 3D printing, etc. In addition, this study investigated how the reinforcement of microcrystalline cellulose can result in a material with enhanced performance as well as its mechanical characteristics (XRD, FTIR, TGA, and SEM characterization). [ABSTRACT FROM AUTHOR]

Fully grouted rock bolts are widely used in mining, tunneling, and pit support, and thus the study of their anchorage performance is beneficial for optimizing the anchorage system design. In this study, an FDM‐DEM coupled numerical model is established to simulate the whole process of rock bolt pullout test and to investigate the failure mechanism of fully grouted rock bolts. The accuracy of the model is verified by comparison with existing laboratory test results. Virtual experiments are conducted on different models by eliminating the anchor plate, changing the layered rock strata condition, and adding bolts. The results show that the presence of an anchor plate will reduce tensile stress to restrain the rupture of surrounding rock and thus improve the strengthening effect. Due to the different bond strength and tensile strength of the soft and hard rock mediums, the layer sequence of the rock strata affects the maximum pullout force. The upper‐soft and lower‐hard composite rock strata (S‐HCR) exhibits single‐cone damage while the upper‐hard and lower‐soft composite rock strata (H‐SCR) exhibits double‐cone damage. The superposition effect of the anchor group on the stresses and displacements is the reason leading to the reduction of the maximum load‐bearing capacity of the rock bolts. [ABSTRACT FROM AUTHOR]

This study focuses on the creation of high degree biocomposite with the utilization of renewable resources, including cardanol oil, palm kernel fiber and chitosan biopolymer. The principal aim of this research was to achieve high degree ratio of biocomposite for safe and eco-friendly application. The chitosan biopolymer was extracted from marine waste sea urchin spikes via deproteination. The biocomposites were prepared via hand layup technique following testing via ASTM standards. According to results, among the composites fabricated, PC5 exhibits exceptional mechanical strength with tensile strength of 88.2 MPa, flexural strength of 133.35 MPa and impact energy of 3.92 J. Therefore, PC6 composite performs better wear resistance with reduced coefficient of friction of 0.399 and Sp. wear rate of 0.01 mm3/Nm, respectively. And also, PC6 provides good thermal resistance with initial decomposition temperature of 345 °C. Similar to mechanical properties, in fatigue behavior also PC5 exhibits high fatigue life cycle counts with 19,647 for 25% UTS, 18,799 for 50% UTS and 17,571 for 75% UTS. The obtained results show that the inclusion of palm kernel fiber and chitosan significantly enhances the mechanical properties, wear and thermal resistance of the composites, while the cardinal oil binder ensures proper adhesion. However, thermal aging conditions were implemented to assess the material's ability to withstand harsh environmental factors. Notably, among the composite materials tested, the designations with chitin (such as PC4, PC5, and PC6) exhibited lesser susceptibility to the effects of thermal aging. This resilience is attributed to the presence of NH2 functional groups within chitin, which play a role in reducing the impact of thermal aging. These discoveries highlight the promising qualities of the developed polyester biocomposites, suggesting their suitability for a wide array of industrial applications requiring materials capable of enduring high-temperature environments such as automotive door panels, structural, space, defense and sports applications. [ABSTRACT FROM AUTHOR]

This research mainly focused on studying the influence of various curing media on the properties of lightweight geopolymer composites. Here, Ground Granulated Blast furnace Slag (GGBS), Paddy straws, and the combination of sodium silicate and sodium hydroxide at the ratio of 2.5:1 were used to produce geopolymer composites. For this experiment, two different parameters, i.e., variation of paddy straw (0, 5, 10, 15, and 20%) and variation of curing media (Intermittent, Heat, and Saline water), were chosen. The compressive strength of a 20% addition of paddy straw is dramatically reduced by 88.6%, while the density is reduced to 40.42%. Maximum flexure and tensile strength were noted as 65.11 and 45.5%, respectively, for the 15% addition of paddy straw. An interesting fact found from the samples cured under Saline water enhanced the overall compressive strength, tensile and flexural strength by 12.85, 45.5, and 21.2%, respectively, compared to the other two curing media. [ABSTRACT FROM AUTHOR]

The requirement of excellent flexural stiffness in construction elements has initiated the use of fibre reinforcement. However, the processing complexity involved in the manufacture of synthetic fibres is environmentally hazardous. The use of natural fibres in geopolymer concrete (GPC) structures was investigated in this work using a hybridisation of natural and synthetic fibre. Natural basalt fibre (BF) was used with synthetic steel fibre (SF) in various proportions in GPC and tests were conducted to evaluate the workability, compressive strength, split tensile strength and flexural strength. It was found that, compared with the plain GPC, the addition of 1.5% BF and 0.5% SF resulted in 45%, 27% and 12% improvements in compressive, split tensile and flexural strengths, respectively. The compatibility between the SF and BF resulted in enhanced post-peak flexural behaviour, with 37% improvements in the modulus of elasticity and stiffness. As BF possesses more tensile strength than SF, the use of 1.5% BF and 0.5% SF provided better flexural and ductility properties than the use of SF alone, which could lead to the development of ductile GPC members under dynamic loading conditions. [ABSTRACT FROM AUTHOR]

Purpose: Congenital diaphragmatic herniae (CDH) may require patch closure in 50% of the cases. We assessed a biologic and composite mesh in a porcine CDH model. Methods: Left sided thoracotomy was performed in 20 pigs. Approximately, 30% of the diaphragm was excised and the patch (Surgisis® or Parietex®) inserted to close this defect. The pigs were killed at 6 months and the diaphragm was harvested for biomechanical and histological assessment. Results: The mean weight of the pigs at surgery and killing were 6.1 kg (4.2–8.4 kg) and 94.1 kg (80–131 kg), respectively. There were two recurrences and three eventrations, all with Surgisis®. There were less dense lung and abdominal adhesions in the Parietex group (P < 0.0001 and 0.025, respectively). The tensile strength of the Surgisis®, the Parietex® groups and controls were similar. There was significantly more muscle in-growth in the Parietex® patch over Surgisis® (p = 0.016). Conclusion: Parietex® and Surgisis® patches at 6 months have a similar tensile strength to normal tissue. All recurrences and eventrations were in the Surgisis® group. Parietex® patches demonstrated more muscle in-growth into the patch compared to Surgisis®. This is the first study utilising Parietex® composite patch in the repair of large diaphragmatic defects in a porcine model. [ABSTRACT FROM AUTHOR]

Herein, a 1300 MPa grade complex phase steel with high formability (CH) is developed, which is achieved through the formation of cementite during pretreatment and the control of austempering temperature to enhance the stability of retained austenite (RA). Due to the insufficient diffusion of Mn during cementite dissolution, Mn enrichment enhances the mechanical stability of austenite, thereby increasing austenite content at room temperature. As the austempering temperature increases from 340 °C to 400 °C, the RA content increases, but its stability decreases significantly. Compared with the content of RA, its stability is more critical for enhancing plasticity. RA formed at lower austempering temperatures is highly stable, enlarging the strain range of the transformation‐induced plasticity effect and improving material plasticity. The experimental steel achieves optimal plasticity while maintaining strength when overaged at 360 °C. Specifically, the yield strength is 963 MPa, the ultimate tensile strength is 1394 MPa, and the total elongation is 14.0%. [ABSTRACT FROM AUTHOR]

Manganese stabilizes the austenite and reduces the stacking fault energy in face‐centered cubic (FCC) structures, promoting the formation of hexagonal and cubic structures. This study investigates the phase transformation and mechanical behavior of extremely low‐carbon FeCrMn austenitic stainless AISI 201 steel subjected to cold drawing in three stages, ultimately reaching a true strain of 0.93. The objective is to examine the transformation from the parent FCC structure to hexagonal close‐packed and body‐centered cubic structures as a combination of transformation‐induced plasticity and twinning‐induced plasticity phenomena. X‐ray diffraction and electron backscatter diffraction analyses are utilized to investigate phase transformations under significant plastic deformation and the crystallographic orientation relationships between phases. Additionally, tensile and hardness tests are performed to assess the impact of plastic deformation on mechanical properties. Results indicate that a true strain of 50% is optimal for balancing strength and ductility in CrMnFe austenitic stainless steel. After applying a true strain of ε1 = 26.7%, yield strength (YS) increases by 192% and ultimate tensile strength (UTS) by 35%, while elongation reduces by 41%. With a further strain of ε2 = 57.5%, YS increases by 71% and UTS by 44%, but elongation drastically decreases by 94%. Applying the final strain of ε3 = 94.0%, YS and UTS only increase by 3% and 2%, respectively, while elongation further reduced by 40%. These findings suggest that a true strain of 50% shall be considered the maximum reduction for maintaining a balance between strength and ductility in CrMnFe austenitic stainless steel. [ABSTRACT FROM AUTHOR]

Composite filaments are of considerable interest in research due to their exceptional performance characteristics and broad applicability. In this study, highly electrically conductive composite filaments comprising cellulose nanofibrils (CNF) and silver nanowires (AgNWs) are carefully prepared, accompanied by the proposition of an integrated microwave‐microfluidic synthesis method for AgNWs. The proposed reaction system exhibits a remarkable capability for swift AgNW synthesis, with a space‐time yield of 1.2 × 104 g (h·m3)−1, approximately five times superior to that achievable through conventional batch reactor methodologies. The microwave‐assisted microfluidic synthesis of AgNWs introduces a novel aspect to the extensive research on 1D nanomaterials. The design of experiments and multi‐objective Bayesian optimization are integrated iteratively to converge toward the global optimum, aiming to enhance screening efficiency and achieve a balanced outcome by maximizing aspect ratio and minimizing size for AgNWs. The AgNWs synthesized under optimal conditions has a diameter of ≈50.4 nm and an aspect ratio of ≈555. Subsequently, they are integrated into composite filaments with CNF, resulting in electrical conductivity and tensile strength of the composite filaments at values of 8.35 × 105 S m−1 and 186 MPa, respectively, surpassing those reported in existing literature for other analogous materials. [ABSTRACT FROM AUTHOR]

Aramid nanofibers (ANFs) exhibit desirable lightweight and excellent properties, while their strength has to be sacrificed to further improve their electrical insulation and fire resistance so as to meet the special demands of extreme environments. Herein, Zylon nanofibers (ZNFs) with analogous structure compatibility but superior performance are employed to construct an assembled dual‐network structure to improve the overall properties of ANFs. A facile in situ structure restoration (ISSR) strategy is proposed to achieve ZNF aqueous dispersion for the first time by deprotonation of ZNFs, which significantly avoids the corrosive acid system and facilitates the papermaking process. The composite ANF@ZNF nanopaper exhibits incredible tensile strength (233 MPa) and toughness (14.7 MJ m−3), increased by 108% and 584% compared with pure ANF nanopaper due to the dense entangled dual‐network and tremendous hydrogen bonds. Moreover, it presents superior breakdown strength of ≈128 kV mm−1, which is 6 times higher than that of commercial Nomex T410 insulation paper with a thickness of 50 µm. Besides, it exhibits surprising flame resistance (endure 1000 °C burning) ascribed to the excellent thermostability of ZNFs. This work provides promising possibilities for expanding the applications of aramid‐based composites for advanced electrical insulation and thermal protection in extremely harsh conditions. [ABSTRACT FROM AUTHOR]

Pathological scars (PS) are involved in the excessive response of inflammation and overactivation of myofibroblasts. Herein, a novel microneedle (MN) patch based on the adipose‐derived stem cell concentrated conditioned medium (ADSCC‐CM) cross‐linked keratin hydrogel is developed to load triamcinolone acetonide (TA), thereby achieving the dual‐drug delivery of ADSCC‐CM and TA to simultaneously reduce the inflammation and guide myofibroblast behaviors. Results not only confirm the ability of ADSCC‐CM to drive the formation of keratin‐based hydrogel, but also verify the dual‐drug release capacities of the hydrogel‐developed MNs (TA@AC‐MN). Using human hyperplastic scar fibroblast (HSF), the combination of ADSCC‐CM and TA demonstrates a pronounced synergistic effect in mitigating the detrimental effects of the inflammatory microenvironment on HSFs, including suppressing the production of reactive oxygen species and attenuating the expression of inflammatory factors. Compared with the clinically used TA, TA@AC‐MN promotes scar biomimetic repair (i.e., optimizing the proportion of collagen and increasing the tissue tensile strength). This study demonstrates that TA@AC‐MN has the capacity to provide a self‐managing and minimally invasive therapeutic strategy for PS. [ABSTRACT FROM AUTHOR]

The inherent low strength of zinc (Zn) alloys limits their application, and aging treatment is a method that can be used to improve the properties of Zn alloys significantly. In this work, the effects of aging temperature on microstructure, mechanical properties, and corrosion resistance of the as‐rolled Zn‐3Al‐1Cu alloy are studied. The results show that the mechanical properties and corrosion resistance of the alloy can be significantly improved by tuning the aging temperature. Through aging treatment, the grain size of the second phase grows and more of the second phase is precipitated, which improves the mechanical properties and plasticity of the as‐rolled Zn‐3Al‐1Cu alloy. The tensile and yield strengths of the as‐rolled Zn‐3Al‐1Cu alloy aged at 80 °C are the highest, which are 206.11 ± 1.63 and 177.57 ± 1.70 MPa, respectively. Conversely, the alloy aged at 160 °C displays the best plasticity, where its elongation reaches 25.66 ± 0.49%. In addition, aging at 160 °C leads to the best corrosion resistance, reaching a corrosion rate obtained by the electrochemical test of 0.0016 mm year−1. [ABSTRACT FROM AUTHOR]

Highlights In this paper, we created a new molded‐hole process to manufacture holes instead of drilling in unidirectional (UD) carbon fiber reinforced plastics avoid fiber discontinuity. Several open hole tensile (OHT) tests were carried out on specimens with Cross ply (CP) and Quasi‐isotropic (QI) stacking sequence with drilled holes and molded holes. At the same time, we established finite element analysis (FEA) models of drilled‐hole laminate and molded‐hole laminate to characterize the stress field around the hole. The numerical analysis results reveals that the max principal strain distribution around the molded hole has much higher coincidence with fiber axial direction than that in drilled‐hole laminate. Moreover, the OHT strength results of QI specimens indicate that the plates with molded holes were more 50% higher than those with drilled holes. This process will provide reference for molded UD CFRP structure holes. And the numerical model can help engineering designer make OHT strength prediction. A new molded‐hole process for unidirectional prepreg was created. Molded‐hole specimens have higher open hole tensile strength than drilled‐hole pieces. The simulation results were close to the experimental results. [ABSTRACT FROM AUTHOR]

Highlights This study is an attempt to develop high‐quality hybrid composites via functionalization (for homogeneous distribution) of the graphene nanoplatelets (FGNP) and then doping to carbon fiber reinforced especial aviation epoxy matrix (Araldite LY5052) via vacuum bagging molding (VBM). The utilized materials were characterized by UV–Vis spectroscopy, tensile, impact, hardness tests, and fracture mode analysis using a scanning electron microscope (SEM). The results revealed a 92% (502.5 MPa) and 85% (490 MPa) improvement in tensile strength values by doping the 1 and 1.5 wt% FGNPs, respectively. There was an improvement in impact strength with the addition of FGNP; a 28% (3.23 J/mm2) increase was achieved in the nanocomposite with 1 wt% FGNP added, and there was a decrease again in the nanocomposite with 1.5 wt% FGNP added. However, it was still 12% (2.83 J/mm2) better than the neat composite. In addition, the results of examining the fractured surface structures of the impact and tensile test specimens were compatible with these results. It reveals a significant separation of fiber‐matrix bonds with 1.5 wt% FGNP contribution. While tensile and impact strengths peak at 1 wt% FGNP value and decrease afterward, hardness values increase in parallel with the increase in FGNPs. Composites were developed by functionalized graphene nanoplatelets (FGNP). The fiber‐matrix interface was strengthened with FGNP interphase. A 92% tensile strength increase was achieved with 1 wt% FGNP additives. 28% in impact strength and 55% in hardness increase by 1 wt% FGNP. The morphology confirmed that the FGNP interphase filled the interface. [ABSTRACT FROM AUTHOR]

This study investigates the joining of dissimilar materials, specifically galvannealed advanced high‐strength steel (AHSS) and glass fiber‐reinforced polyamide 6 (PA 6) to achieve lightweight automotive. AHSS and PA 6 are widely used in the automobile industry; however, a direct joining of those two materials is difficult owing to their great difference in physical properties. Therefore, laser surface texturing (LST) and plastic injection molding are adopted to join AHSS and PA 6, which can create a strong mechanical interlock between AHSS and PA 6, resulting in an excellent joint strength compared to other joining techniques. The effects of LST parameters (groove depth and hatch distance) and injection molding temperatures on the joint strength are examined. The maximum AHSS‐PA 6 joint strength is measured at 72.3 MPa. Additionally, the microstructure and mechanical properties of recast, which develops over the original metal surface by melting and resolidifying, are analyzed. Compared to the base metal, the recasts exhibit higher hardness due to smaller grain sizes. PA 6 fills the laser‐textured grooves and spaces between the recasts, acting as a mechanical interlock that enhances joint strength under tensile shear testing. [ABSTRACT FROM AUTHOR]

With the development of the "paper instead of plastic" trend, the investigation into high‐density, heavy‐weight paper has emerged as a point of interest in both academic and industrial realms. Regrettably, the paper‐strengthening agents that are commercially available fall short of meeting the strength specifications for such papers. To rectify this shortcoming, a water‐based acrylate paper‐strengthening agent (AA) was developed through radical emulsion polymerization. The most stable acrylate emulsion was obtained by amalgamating the anionic emulsifier allyloxyammonium oxymethyl sulfate nonylphenol ethoxy sulfate (DNS‐86) with the nonionic emulsifier nonylphenol polyoxyethylene ether (OP‐10) at a proportion of 1:0.6, with a dosage of 3%. Substituting the conventional strengthening agent (styrene‐butadiene latex) with the synthesized acrylate emulsion in wet‐end addition markedly improved the paper strength, registering a 54.8% increase to 29.4 MPa. The introduction of carboxylated cellulose nanofibers (C‐CNF) further bolstered the mechanical properties of the paper, achieving a tensile strength of 41.44 MPa and an elongation at a break of 3.55%. These results underscore the efficacy of acrylate as a paper‐strengthening agent and the crucial role of C‐CNF in enhancing the structural integrity of paper materials. [ABSTRACT FROM AUTHOR]

It is difficult to recycle classic thermosetting plastics. Although some of them can be reprocessed, the mechanical properties decline linearly after processing. In addition, most thermosetting plastics are not environmentally friendly and difficult to degrade, resulting in a lot of pollution and limiting their practical application potential. In this paper, the prepolymer is synthesized by using castor oil (CO), hydroxyl terminated polydimethylsiloxane (PDMS‐OH), and toluene diisocyanate (TDI). Using 4,4'‐diaminodiphenyl disulfide (ODD) as a chain extender with dynamic disulfide bond and aniline (An) as a blocking agent, polysiloxane‐aminoester (SiCPUO) with recyclable function under DMF induction was prepared. The effect of the amount of rigid chain extender (ODD) containing disulfide bond on the properties of SiCPUO was studied, its heat resistance will first increase and then decrease with the increase of ODD content, especially the mechanical properties are more obvious, this trend has never been reported before; the mechanical properties and recyclability of SiCPUO are tested, and the comprehensive performance of SiCPUO2 is the best, the tensile strength is 0.84 MPa and the elongation at break was 65.81%; the solubility test of different solvents showed that it has recyclability, recovery rate is 95%;the material has self‐healing function, the repair efficiency is up to 95%. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the influence of pre-heating characteristics on the mechanical properties and forming process of selective laser sintering (SLS) printed PES-HmA samples. An experimental setup with four heating tubes was designed to study the pre-heating temperature distribution on the powder bed. The pre-heating temperature distribution on the powder bed was captured using a thermal imaging camera. A method for evaluating pre-heating temperature distribution based on the average and standard deviation of surface temperature was proposed. The heating tube installation position was optimized using a response surface experiment study based on the temperature distribution evaluation. By optimizing the installation position of the tubes, the temperature distribution on the powder bed tends to become uniform. The effect of pre-heating temperature value and distribution on the mechanical properties of the SLS printed PES-HmA samples was also experimentally investigated. The cross sectional microstructure of the printed samples were examined by scanning electron microscope to analyze the layer formation process at different pre-heating temperature. By increasing the pre-heating temperature from 70°C to 100°C, the material diffusion at the layers interface was improved, which made the tensile strength of sample increased by 376%, and the flexural strength increased by 224%. [ABSTRACT FROM AUTHOR]

The goal of this article was to analyze the microstructural, texture development, deformation mode, and mechanical properties of a Mg–8.7Gd–4.18Y–0.42Zr (wt%) magnesium alloy that underwent conventional extrusion in conjunction with equal channel angular pressing (EX-ECAP) deformation. The findings indicate that as-extruded alloy reveals a significant basal texture, while the ECAPed GW94K alloy demonstrates basal poles that are inclined ~ 45° from the extrusion direction. After 4p-ECAP process at 370 °C via the Bc path, the microstructure of the alloy exhibits a high level of uniformity, with a fine grain area fraction of 92.7% and an average grain size of 3 μm. The GW94K alloy experiences a significant increase in elongation when the ECAP pass is increased, although the ultimate tensile strength (UTS) decreases remarkably. In particular, the sample subjected to ECAP demonstrates a room-temperature tensile elongation of 36.8% in the extrusion direction. This phenomenon can be ascribed primarily to the evolution of the texture during repeated ECAP processes, leading to the activation of multiple deformation modes in ECAP deformation process of the GW94K alloy. Furthermore, the results suggest that the presence of multiple slip systems, characterized by their high Schmid factor and IGMA analyses, significantly influences the uniform elongation. [ABSTRACT FROM AUTHOR]

Lightweight, flexible, and thermostable thermally conductive materials are essential for enhancing heat dissipation efficiency in advanced electronics. The development of intrinsic thermally conductive polymers is the key to expanding the space for improving the thermal conductivity of polymer‐based thermal management materials. In order to balance the thermal conductivity and mechanical performance of bulk polymers, thermally conductive aramid nanofiber (ANF) films are assembled by manipulating the proton‐donating ability of solvents. Compared to water as a conventional proton donor, ethanol‐induced multi‐scale structures composed of dense hydrogen bonding interaction, large grain size, and uniform fiber topology endow the resulting ANF films with enhanced intrinsic thermal conductivity up to 5.05 W m−1 K−1 with a 34% increase, salient mechanical performance with the tensile strength of 181.4 MPa, and exceptional thermal stability higher than 500 °C. These outstanding properties of ANF films provide many possibilities for the preparation of polymer‐based thermally conductive materials. [ABSTRACT FROM AUTHOR]

Highlights Wind turbines are subjected to extreme weather and load conditions; hence, high strength and impact resistance are required. Furthermore, wind turbine blades can be subjected to impact loads such as bird strikes, resulting in the formation of microcracks. Self‐healing capsules can be used to mend turbine blades for microscale damage. The incorporation of self‐healing capsules may cause a decrease in the mechanical characteristics of the composites prior to impact resistance, which can be compensated for with efficient fillers such as silicon carbide whiskers (SiCw). Thus, a novel hybrid composite structure is examined with the advantage of using a self‐healing mechanism and SiCw reinforcement. Tensile, tribological, and Charpy impact tests were performed to characterize the mechanical and tribological properties, which were supported with microscopic observations. Multiple experimental characterizations were performed to investigate the impact, and the ultimate tensile strength (UTS) and energy absorption capacity of the structure were shown to increase by 32% and 45%, respectively, with the addition of SiCw. The presence of self‐healing agents provides a 5% rise in UTS after enough time for healing following the collision. The structure's tribological performance is improved by 10% in wear resistance and 20% in friction coefficient. Hybrid laminated composite structure with silicon carbide whisker and self‐healing capsules. Tensile and Charpy impact tests conducted with microscopic observations Increased ultimate tensile strength and energy absorption capacity by 32% and 45%. Tribological improvement by 10% in wear resistance and 20% in friction coefficient. [ABSTRACT FROM AUTHOR]

There is a need for cost‐effective manufacturing methods to optimize the impregnation and mechanical properties of carbon fiber reinforced thermoplastics (CFRTPs) by overcoming the low flowability of thermoplastics due to their high melt viscosity. In this study, to improve the impregnation of the CFRTP by inducing low melt viscosity, a strategy to control the molecular weight (MW) of thermoplastic polymer was developed. Through the quad‐screw extrusion (QSE) process, as the rotational speed of the QSE increased, the MW of the polypropylene (PP) matrix decreased, resulting in improved flowability and impregnation characteristics of the matrix, as well as enhanced mechanical strength of the CFRTP. The tensile and flexural strengths of the CFRTP were optimized at 1500 rpm, resulting in 77% and 23% improvements, respectively, compared to the CFRTP with raw PP. Therefore, the applied QSE process effectively controlled the MW, melt viscosity, and flowability of the PP matrix and produced CFRTP with improved mechanical strength. Highlights: Mechanical degradation using QSE was applied to improve flowability of matrix.As polymer chain length decreased, impregnation between CF and matrix was improved.The improved impregnation characteristics resulted in the improved mechanical strengths.There is an optimal matrix MW to optimize the mechanical strengths of CFRTP. [ABSTRACT FROM AUTHOR]

In this study, the effects of polypropylene (PP) composites produced by adding 10% old newspaper fibers (ONP), 5% microcrystalline cellulose (MCC), 3% polypropylene carbonate (PPC), and waste toner from 1% to 4% on the mechanical properties, physical properties, morphological, and thermal properties were investigated. According to the FTIR‐ATR and SEM‐EDS analysis results, it was determined that a significant part of the waste toner used in the study consisted of polystyrene co‐acrylate, and the remaining part consisted of carbon black and trace amounts of silicate. In the research, it was determined that the flexural and tensile strengths of MCC/ONP/PP composites containing 1% waste toner and 3% PPC increased by 13% and 46%, respectively, compared to the control sample. Additionally, the samples with the lowest water absorption values were measured in composites containing 1% waste toner and 3% PPC. The highest crystallinity value (50.75%) was obtained with the use of 1% waste toner and 3% PPC in MCC/ONP/PP composites. However, with waste toner usage above 1%, the mechanical, thermal properties, and water absorption rate have slightly decreased. As a result of the study, it was concluded that up to 1% waste toner with 3% PPC can be used successfully in MCC/ONP/PP composites. [ABSTRACT FROM AUTHOR]

Polymer nanocomposites have found wide industrial applications, necessitating optimal mechanical and fracture properties evaluation, traditionally done through costly experimental methods. This study employs machine learning, particularly XGBoost, to predict properties like tensile and fracture properties swiftly, aiding material innovation across industries. The research investigates unvulcanized and vulcanized polypropylene (PP)/ethylene propylene diene monomer (EPDM) reinforced with clay and halloysite nanoparticles (HNT), analyzing fracture properties via essential work of fracture (EWF). Experimental design selects tests, and an XGBoost model predicts tensile strength and modulus, strain at break, EWF, and non‐EWF based on EPDM and nanoparticle percentages, composite and nanoparticle types. The model accurately predicts tensile strength and modulus but less so for strain at break, EWF, and non‐EWF. Mean Absolute Percentage Error values for training/test are 0.49/1.21, 1.05/1.55, 34.21/42.76, 3.02/14.35, and 2.89/3.78, with determination coefficients of 0.99/0.98, 0.99/0.97, 0.97/0.91, 0.97/0.79, and 0.92/0.73. Nanoparticles mainly affect outputs, with EPDM secondarily impactful, while composite and nanoparticle types exhibit similar significance. The best‐performing polymer nanocomposite is a dynamically vulcanized one containing 10 wt% EPDM and 3 wt% clay, achieving tensile strength of 25.070 MPa, tensile modulus of 261.170 MPa, EWF of 75.300 N/mm, and non‐EWF of 10.150 N/mm2. Highlights: The effects of ethylene propylene diene monomer (EPDM), clay and halloysite nanoparticles on the mechanics of polypropylene‐based nanocomposites.Essential work of fracture (EWF) was used to study the fracture properties.Machine learning was employed to predict all mechanical characteristics.The vulcanization process improved all mechanical characteristics.The best compound: vulcanized one containing 10 wt% EPDM and 3 wt% clay. [ABSTRACT FROM AUTHOR]

The high‐strength and lightweight carbon fiber‐reinforced composites are widely used in various industries. Fused Filament Fabrication (FFF), the most cost‐effective Additive Manufacturing (AM) technology, has gained significant application advantages in the industry. The objective of this study is to improve the toughness of the carbon fiber‐reinforced polyamide composites used for FFF. In this work, HDPE was selected to reduce the hygroscopicity of PA6 while lowering the cost, carbon fiber was introduced to reinforce the PA6/HDPE blend. The elastomer POE‐g‐MAH was applied to increase the toughness of the composites as well as to improve the compatibility of the incompatible system of PA6/HDPE. Mechanical tests and micromorphology observation were carried on the FFF printed samples. The test results show that when 20 phr POE‐g‐MAH was added, optimum mechanical properties were obtained for the composites with about 18.9 wt% carbon fiber content. The tensile strength reached 94.1 MPa, and the notched impact strength reached 21.0 kJ/m2, which were 180.8% and 610.7% higher than that of the neat PA6, respectively. It is applicable for various applications that require high‐impact strength, including automotive parts and some machine components. Highlights: The PA‐2CF‐C20 composite exhibits high strength and high toughness, the tensile strength reaches 94.1 MPa and the notched impact strength reaches 21.0 kJ/m2.Successfully prepared cost‐effective and high‐performance filament for FFF 3D printers. [ABSTRACT FROM AUTHOR]

Researchers and scientists have focused on the development and future opportunities of flexible sensors in food, environment and defense fields. In this study, we propose a flexible substrate material‐based nanofibril cellulose empty fruit bunch (NEFB)‐reinforced thermoplastic polyurethane (TPU) blend nanocomposite for flexible substrate materials. Untreated and treated nanofibril cellulose samples of empty fruit bunch (NEFB, 0, 1, 2, 3, 4 wt. %) were treated with 6 wt.% sodium hydroxide (NaOH) and subjected to internal Brabender mixer followed by a hot‐pressing machine. The density and tensile and dynamic mechanical properties of the nanocomposites were investigated for the treated and untreated samples. Tensile properties were characterized using a Universal Testing Machine, and the fracture mechanism after post‐tensile testing was determined by scanning electron microscopy (SEM). Increasing the content of untreated NEFB/TPU improved the tensile strength compared with 6% treated NEFB/TPU blend nanocomposites. Incorporating the nanofibril cellulose of empty fruit bunch at 2% into the TPU blend nanocomposites significantly increased E′, E" and Tg compared with other formulations. Highlights: Nanocellulose derived from plants is considered a promising material for flexible substrates in electronics due to its robust mechanical properties and eco‐friendliness.Malaysia's abundant empty fruit bunch (EFB) resources make it a possible source of nanocellulose, which improves the properties of polymers.The effect of sodium hydroxide (NaOH) treatment on the compatibility of EFB‐derived nanocellulose with polymer matrices was investigated.The addition of nanocellulose, particularly at a concentration of 1%, significantly increases the tensile strength of thermoplastic polyurethane nanocomposites, whereas 6% NaOH treatment has no effect.Dynamic mechanical analysis reveals high storage modulus at 2% nanofibril cellulose empty fruit bunch (NEFB) and energy dissipation at 4% NEFB as well as enhanced interfacial bonding at 1% NEFB. [ABSTRACT FROM AUTHOR]

Highlights Additive manufacturing encounters significant barriers to its broader application in large‐scale production. This research seeks to mitigate critical limitations, including a trade‐off between impregnation speed and quality in filament preparation and inconsistent fiber distribution in continuous carbon filaments (CCFs), mainly attributed to the rounding process of unidirectional tapes and insufficient interlayer adhesion. A novel lab‐scale impregnation line was engineered to address these challenges, facilitating the production of CCFs using three distinct types of carbon fiber in conjunction with recycled glycol‐modified poly(ethylene terephthalate) (rPETG) resin. This new lab‐scale process produces uniform fiber distribution within PETG matrix and prevents S‐shaped distortions typically observed in conventionally rounded tapes. The type of carbon fiber sizing influences the impregnation process and tensile strength of the CCFs. Specifically, CCFs with flexible sizing demonstrated a 15% reduction in tensile strength due to fuzz formation during impregnation. These CCFs were subsequently employed in 3D printing applications, with the fabricated composite components subjected to interlaminar shear strength (ILSS) testing. The study concludes that recycled PETG is a viable additive manufacturing material when combined with appropriately sized carbon fibers. Additionally, it highlights the advantages of omitting the rounding stage, which enhances the quality of CCF and optimizes production efficiency. A lab‐scale direct melt impregnation system was designed in this study. The impact of different sizing types on carbon fibers was investigated. 3D‐printed continuous fiber filaments were prepared. New lab‐scale process produces uniform fiber distribution within PETG matrix. S‐shaped distortions observed in conventionally rounded tapes were prevented. [ABSTRACT FROM AUTHOR]

Highlights The potential of polytetrafluoroethylene (PTFE) products as surgical dressings is considerable, yet their absence of antibacterial properties substantially restricts their medical applications. To enhance the utility of PTFE in the medical sector, this research loaded nano zinc oxide (ZnO) particles into the PTFE filament matrix through a wet spinning process. This approach successfully yielded PTFE/ZnO composite filaments with antibacterial properties. The characterization results of the filaments show that when the mass ratio of PTFE to ZnO is 8:1, the filament has the best mechanical performance with a tensile strength of 6.78 MPa and an elongation at break of 274.46%. At the same time, composite antibacterial filaments under different process conditions show excellent antibacterial effects against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), with an antibacterial rate of over 99%. The excellent mechanical properties ensure the ability to further process single filaments, which can be woven into fabrics, textiles, and various other products. Therefore, the composite antibacterial filaments with excellent comprehensive performance prepared in this study are expected to be applied in the field of medical fabrics. Provide new solution ideas for functional PTFE composite filaments preparation. The prepared PTFE/ZnO composite filament has good acid and alkali resistance as well as excellent antibacterial properties, which is expected to broaden the application field of PTFE filaments. [ABSTRACT FROM AUTHOR]

Natural fiber-reinforced biocomposites offer sustainable alternatives to conventional plastics. This study investigates the development of biocomposites using coconut spathe fiber, a renewable byproduct, reinforced with corn starch and poly(vinyl alcohol). The composites demonstrated significant mechanical properties, including a tensile strength of 46.8 MPa, flexural strength of 42.1 MPa, and an impact strength of 11.2 kJ m−2. Water absorption was limited to 33.6% after 24 hours, indicating hydrolytic stability. Biodegradation tests confirmed the complete breakdown of the material in composting conditions. These findings highlight the potential of coconut spathe-based biocomposites for applications in the automotive and packaging industries, addressing the need for sustainable and biodegradable materials in place of non-degradable thermoplastics. [ABSTRACT FROM AUTHOR]

Six varieties of alkoxy polyhedral oligomeric silsesquioxanes (POSSs) featuring methoxy, ethoxy, n‐propoxy, isopropoxy, n‐butoxy, and n‐hexoxy as terminal groups were synthesized using the direct dehydrogenation condensation method. These POSSs were then incorporated as cross‐linking agents into hydroxy‐terminated polydimethylsiloxane (HPDMS) to create various formulations of room temperature vulcanized silicone rubbers (RTV SRs), denoted as SRM, SRE, SRP, SRI, SRB, and SRH. The morphology, thermal stability, and mechanical properties of the resulting SRs are analyzed using scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and universal tensile testing machine. The findings indicate that the incorporation of POSS into SRs results in significant enhancements in thermal stability and mechanical properties when compared to the control group (TEOS/SR). SRB and SRH exhibit the highest cross‐linking density and tensile strength. Specifically, SRB‐4 demonstrates the highest tensile strength at 2.66 MPa, representing an 8.6‐fold increase compared to TEOS/SR. The maximum decomposition rate temperature of SRP‐4 reaches 527°C and is 194°C higher than TEOS/SR. Because the alkoxy groups with different chain lengths on POSS have different chemical reactivity, they have a great effect on the dispersion of POSS in SRs, which affect the cross‐linking density, tensile strength, and thermal stability. [ABSTRACT FROM AUTHOR]