ABSTRACT This study investigates the influence of printing parameters—layer height, infill density, and infill pattern—on the mechanical performance and surface damage behavior of PLA components fabricated via Fused Filament Fabrication (FFF). The focus is on evaluating how these parameters affect force–displacement characteristics and crack initiation under Erichsen indentation testing. Fifteen parameter combinations were tested using three‐layer heights (0.10, 0.15, 0.20 mm), five infill densities (10%–90%), and seven infill patterns (Grid, Triangles, Cubic, Octet, Concentric, ZigZag, and Cross). Force–displacement curves, peak force, displacement, and energy absorption were analyzed. Post‐test surface damage was correlated with mechanical results to assess crack propagation and failure behavior. Results showed that increasing layer height raised maximum force but reduced ductility. Higher infill densities enhanced load‐bearing capacity but limited deformation, particularly above 70%. Triangles and Cubic patterns provided superior strength and controlled crack propagation, while Cross and Concentric patterns exhibited early failure. Surface damage analysis revealed that high infill density combined with optimal pattern design guided cracks more symmetrically. This work offers an experimental assessment of how FFF parameters affect both mechanical and failure behavior of PLA under indentation, contributing valuable insights for improving the structural performance of additively manufactured parts.

ABSTRACT Dye pollution in aquatic environments poses severe threats to ecological systems and human health. Hydrogels, featuring abundant functional groups and large specific surface area, are promising dye adsorbents. We aimed to develop a facile, rapid synthesis strategy for hydrogels with superior swelling performance and high cationic dye adsorption capacity. This was achieved via free radical copolymerization of AA, AMPS, and NVP. The synthesized hydrogel AA/AMPS/NVP exhibits a remarkable swelling ratio of 1202 g·g −1 in deionized water and 175 g·g −1 in 0.9% NaCl solution. Adsorption experiments reveal that the methylene blue (MB) adsorption capacity of the hydrogel is influenced by contact time, initial MB concentration, temperature, and solution pH. Kinetic analysis shows that the adsorption process is fitted by the pseudo‐second‐order model. Isotherm study indicates that MB adsorption follows the Langmuir model, with a maximum adsorption capacity of 1290.54 mg·g −1 . After 5 adsorption–desorption cycles, the MB removal efficiency remains at 58.38%. FT‐IR analysis shows that chemical adsorption dominates the interaction between MB molecules and the hydrogel, involving electrostatic attraction and hydrogen bonding between MB cations and functional groups (COOH, SO 3 H) of the hydrogel. Collectively, AA/AMPS/NVP exhibits great potential as an efficient and reusable adsorbent for the remediation of wastewater.

ABSTRACT Polyvinyl alcohol (PVA) is a synthetic and biodegradable polymer with high oxygen barrier property. However, its practical application as coatings in food packaging is limited by insufficient mechanical strength, poor water resistance, weak UV shielding performance, and a lack of active antimicrobial functionality. In this study, polyethyleneimine (PEI) modification not only improved the dispersion of Ti 3 C 2 T x MXene but also endowed the PVA film with enhanced mechanical properties, superior water resistance, barrier performance, antimicrobial, and UV‐shielding capabilities. The results showed that compared with neat PVA film, the nanocomposite with 4 wt% PMXene (PEI modified MXene) exhibited a tensile strength increase from 27.8 MPa to 38.4 MPa, representing a 38% improvement. The water vapor transmission rate decreased from 35.5 g/m 2 ·24 h to 29.0 g/m 2 ·24 h, and the oxygen transmission rate dropped from 1.5 cm 3 /m 2 24 h to 0.7 cm 3 /m 2 ·24 h. The PVA nanocomposite coating with 6 wt% PMXene blocked 97% of UV light and exhibited antibacterial efficacy exceeding 99% against Staphylococcus aureus and Escherichia coli . A fruit preservation test further confirmed that the composite coating can effectively prolong the storage life of cherry tomatoes. Therefore, these PVA nanocomposites demonstrate potential use in packaging applications in the food industry and pharmaceutical storage fields.

ABSTRACT This study explores the synergistic effects of hybrid graphite (GR) fillers combined with carbon fibers (CFs) and carbon black (CB) on the performance of PVDF‐based conductive polymer composites (CPCs). Composites were formulated with a fixed GR loading of 60 wt% using optimized mixtures of GR particle sizes: G1 (5.9 μm), G2 (17.8 μm), and G3 (561 μm). To investigate the synergistic effect of hybrid carbon additives on CPCs performance, up to 10 wt% of GR was replaced with CB, CF, or a CB/CF mixture. The G2/G3 (3:1) system showed optimal binary GR performance, with a decomposition temperature of 425°C, through‐plane/in‐plane resistivities of 0.66/0.58 Ω cm, and flexural/compressive strengths of 41.5/17.1 MPa. Replacing 7.5 wt% of G2/G3 with CF improved thermal stability (440°C) and lowered through‐plane/in‐plane resistivities (0.33/0.17 Ω cm), although it slightly decreased flexural/compressive strengths (37.2/13.0 MPa). Replacing 5 wt% with CB reduced thermal stability (400°C) but further lowered both resistivities (0.23/0.16 Ω cm), along with reducing strengths (19.5/5.2 MPa). A ternary mixture (CF/CB: 2.5/7.5 wt%) yielded the best electrical performance (0.097/0.087 Ω cm), modest strengths (16.1/3.6 MPa), and a decomposition temperature of 402°C. These results highlight how tuning filler size and composition enhances the multifunctional performance of PVDF‐based CPCs.

ABSTRACT Polylactic acid (PLA) has been widely utilized in modern industries; however, during practical processing operations such as extrusion and injection molding, it consistently exhibits a sufficiently slow crystallization rate and low crystallinity. This study intends to investigate the influence of processing conditions on the solidification behavior of PLA during the injection molding process. The enthalpy transformation method (ETM) was employed to analyze the temperature decays throughout the entire injection process, with a focus on the effects of different cooling parameters on solidification kinetics. Four cooling conditions (denoted as Cases A–D) were compared, and the analysis results of these cases revealed that the melt cooling rate was heavily influenced by the mold temperature. The movement of the phase interface during melt solidification under various scenarios was also examined. Based on the experimental results, position‐dependent characteristics of the phase transition plateau were identified. It was found that its width gradually increased from the wall to the sample centerline. This finding can be utilized in designing the cooling parameters for crystalline polymers during the injection operation. A comparative analysis was conducted between experimental cooling time and predicted cooling curves of PLA. Under varying cooling conditions, a generalized equation derived from fitting parameters using TPM (Three‐Parameter Model) II was found to provide reasonably accurate estimates for injection‐molded crystalline polymers, as supported by both experimental and calculated results. The present work offers valuable insights for designing cooling parameters for crystalline polymers in injection molding processes and provides a theoretical foundation for the future development of PLA composites.

ABSTRACT Lower thermal stability class and thermal conductivity ( λ ) of mica tape limit the service life of stator winding insulation in large generators. A novel mica tape composite was prepared by replacing epoxy resin with heat‐resistant polyesterimine and incorporating hexagonal boron nitride (h‐BN) filler, mica paper, and glass fiber cloth, which can overcome the thermal stability and λ of epoxy tapes, with a multiscale model established for performance prediction. The experimental results demonstrate that the h‐BN‐modified polyesterimine resin mica tape exhibits a heat‐resistant class of H. At an h‐BN loading of 25 wt%, the λ of the h‐BN‐modified polyesterimine resin mica tape attains 0.497 W/(m K), representing a 116.09% enhancement compared to the polyesterimine resin mica tape (0.23 W/(m K)). Through integration of the Y. Agari and Series model, a second‐order thermal conductivity model (Y–S) was developed for h‐BN‐modified polyesterimine resin mica tape composites, demonstrating enhanced accuracy in predicting λ . Furthermore, the h‐BN‐modified polyesterimine resin mica tape composites prepared in this paper exhibit excellent dielectric properties, with a material insulation strength of > 30 kV/mm. This provides a new approach for the preparation of mica tape composites with high heat‐resistance class and high thermal conductivity.

ABSTRACT Traditional hydraulic fracturing technology suffers from low proppant efficiency and significant formation damage due to its reliance on high‐viscosity fluids. While phase‐change fracturing fluids overcome these issues by generating proppants in situ through liquid injection and formation‐triggered phase transformation, existing systems still face challenges such as inadequate proppant strength and poorly defined interfacial control mechanisms. This study aims to develop a novel phase‐change fracturing fluid system (MPCF) with enhanced strength, minimal reservoir damage, and high conductivity through molecular design and interfacial engineering. By introducing dicyclopentadiene (DCPD) into unsaturated polyester resin, a high‐strength functional monomer (PGC1) was synthesized, increasing its compressive strength from 42 to 95 MPa. The optimal MPCF formulation was established alongside an ideal interfacial tension range of 3.2–4.5 mN/m. Under these conditions, the resulting phase‐change proppant (MP) exhibits excellent comprehensive performance: sphericity of 0.9, breakage rate of only 1.5% at 60 MPa, and acid solubility as low as 0.18%. Flow capacity tests confirmed that MP outperforms conventional proppants across the 0–60 MPa closure pressure range. This work provides both a theoretical framework and a practical solution for improving proppant placement and fracture sustainability in unconventional reservoirs.

ABSTRACT Nanogenerators based on pyroelectric and triboelectric effects offer excellent output performance and mechanical flexibility, making them promising for self‐powered sensing and energy harvesting applications. The novelty of this study is strengthened by the relatively limited prior research addressing these distinct effects separately, emphasizing its potential for advancing multifunctional energy harvesting technologies. In this work, polyvinylidene fluoride/lead zirconium titanate (PVDF/PZT) composite films were fabricated to independently harness thermal and mechanical energy for electrical energy generation. Fourier‐transform infrared spectroscopy confirmed enhanced β ‐phase formation, with the 5 wt% PZT‐loaded film (within a 15 wt% PVDF matrix) exhibiting the highest β ‐phase content and improved crystallinity compared to 10 and 15 wt% PZT compositions. A phase‐sensitive method was utilized to evaluate the pyroelectric current of both pristine PVDF and its composite films, where the 5 wt% PZT composite demonstrated a pyroelectric energy conversion figure of merit of 0.416%. Triboelectric testing also showed enhanced charge generation for the same composition, confirming 5 wt% PZT as an efficient hybrid material capable of harvesting thermal as well as mechanical energy. The 5% PZT composite exhibits a peak‐to‐peak open‐circuit voltage (V PP ) of 6.8 V and an output current (I oc ) of 5.6 nA.

ABSTRACT With the escalating severity of air pollution and its associated threats to human health, there is an urgent need to develop high‐efficiency air filtration materials to mitigate the risk of particulate matter inhalation. This study employed electrospinning technology to fabricate SiO 2 aerogel composite nanofiber membranes with enhanced filtration performance by incorporating SiO 2 aerogel into the spinning solution. The influence of SiO 2 aerogel content on the microstructure, thermal stability, filtration performance, and water resistance of the nanofiber membranes was systematically investigated. The results indicated that the composite membranes exhibited uniform fiber diameter distribution and maintained filtration efficiencies exceeding 99%. The membrane with 0.5 wt% SiO 2 aerogel content demonstrated an optimal balance between filtration efficiency (99.54%) and pressure drop (66.72 Pa). Furthermore, the prepared membranes exhibited excellent air permeability (62.55 mm/s) and suitable hydrostatic pressure resistance (613 Pa), which are beneficial for practical applications. This study successfully developed nanofiber membranes integrating high filtration efficiency, breathability, and hydrophilicity, contributing to reduced inhalation risks of harmful particles and holding significant potential for advancing the development and application of high‐performance air filtration materials.

ABSTRACT Methanol (MeOH) and acetonitrile (MeCN) are highly polar organic compounds occurring in HPLC waste eluates. Neither of them is evidently more hydrophilic, which renders their pervaporative separation unusual. To identify suitable membrane materials, the pervaporation of MeOH‐MeCN mixtures having composition near the azeotrope (68.3 mol % MeOH at 35.0°C) was studied. For this purpose, homogeneous membranes from well‐established polymers were investigated, namely cellulose triacetate (CTA), polysulfone (PSU), poly(1‐trimethylsilyl‐1‐propyne) (PTMSP), Matrimid (MIM), poly(dimethyl siloxane) rubber (PDMS), polylactic acid (PLA), and chloroprene rubber (CR). Materials with discernible MeCN selectivity, namely CR, MIM, and PDMS, were further examined at 35.0°C, 45.0°C, and 52.9°C with feeds of varying composition. Plasticization and swelling effects were analyzed using Broadband Dielectric Spectroscopy (BDS) and liquid sorption measurements. Permeability decreased with increasing content of the less sorbing MeOH (except for MIM); BDS measurements indicated plasticization by both components; MeCN sorbed more and appears more organophilic.