Journal of Applied Polymer Science最新文献

Chitosan was extracted from local shrimp shells with a yield of 35.0% and converted into a novel Schiff-base derivative (Cht-SS-TIP) through condensation with 4-[(5-sulfanyl-1,3,4-thiadiazol-2-yl)imino]pentan-2-one. Structural confirmation via FTIR, elemental analysis, and SEM demonstrated successful functionalization, achieving a degree of deacetylation of 74.6% and a high substitution degree of 61.0%. Cht-SS-TIP exhibited a substantial improvement in biological performance relative to native chitosan. Antibacterial assays showed increased killing efficiencies ranging from 64% to 88%, with the strongest activity against Staphylococcus aureus and Bacillus subtilis. Antifungal evaluation revealed potent inhibition of 88% for Aspergillus fumigatus and 84% for A. niger, outperforming unmodified chitosan by more than 20%. Molecular docking against the Pseudomonas aeruginosa LasR quorum-sensing regulator further supported these findings, yielding a favorable binding score of −8.4 kcal/mol and demonstrating stable interactions through hydrogen bonding with LEU110, THR75, ASP65, and π–π stacking with TRP88. The low re-docking RMSD values (1.56 Å for the native ligand and 1.63 Å for Cht-SS-TIP) confirm protocol reliability. Overall, this study establishes Cht-SS-TIP as a high-performance chitosan derivative that synergistically enhances antimicrobial efficacy through structural modification and quorum-sensing inhibition, positioning it as a promising, sustainable candidate for disinfectant formulations and anti-virulence strategies targeting resistant pathogens.

This study integrates digital light processing (DLP)-based additive manufacturing with systematic modulation of trimethylsilyl silane (TRIS) content to elucidate the combined effects of formulation and processing on the performance of 2-hydroxyethyl methacrylate (HEMA)-based hydrogel contact lenses. HEMA hydrogels containing 0–20 wt% TRIS were fabricated via DLP 3D printing and evaluated in terms of physical, optical, thermal, mechanical, and biological properties. Equilibrium water content ranged from 22% to 36%, reaching full swelling within 24 h, while static water contact angles varied between 43° and 63°. All samples exhibited excellent optical transparency (95.8%–98.5%) in the visible range, with effective UV blocking below 240 nm. Differential scanning calorimetry showed that the glass transition temperature increased from 14°C (HT0) to 47°C at 10 wt% TRIS, followed by a slight decrease at higher TRIS contents. Dry-state tensile strength decreased with increasing TRIS, whereas hydrated samples exhibited reduced strength but enhanced elongation. Cytocompatibility tests using ARPE-19 cells confirmed high viability (≥ 96%) for all formulations. Protein adsorption remained low, and bacterial adhesion was significantly reduced, particularly against Escherichia coli and Staphylococcus aureus , with maximum reductions observed at 5–10 wt% TRIS. Overall, formulations containing 5–10 wt% TRIS provided an optimal balance of hydration, transparency, thermal stability, mechanical compliance, and antimicrobial performance, highlighting their potential for biocompatible contact lens applications.

The thermal response of polymethyl methacrylate (PMMA) during deformation is highly relevant to its mechanical properties. In this study, temperature observation experiments were conducted on PMMA under uniaxial tiered cyclic loading. The temperature change characteristics and their mechanisms before yielding were investigated based on dissipated energy. The deformation of PMMA before yielding can be subdivided into four stages: linear elastic deformation, nonlinear deformation, pre–yielding, and yielding stage. Heat generation in loaded PMMA mainly includes the thermoelastic effect, viscous dissipation effect, and thermoplastic effect. Both viscous dissipation effect and thermoplastic effect cause the temperature and stress to deviate from linearity. The temperature decrease exhibits hysteresis relative to the stress under the unloading condition. The temperature hysteresis at low stress levels can be attributed to viscous deformation, while at high stress levels, it is primarily due to plastic deformation. Besides, some “irrecoverable temperature” cannot be recovered at the end of each cycle. The significant stage characteristics of the irrecoverable temperature are highly consistent with the deformation. This study suggests that temperature is an important parameter for reflecting the PMMA properties, and provides a new idea for monitoring and identifying the deformation regimes of the PMMA.

Nanocomposite materials that combine metal oxides with conducting polymers are increasingly explored for multifunctional biomedical applications. Cerium oxide (CeO) nanoparticles exhibit strong redox activity and reactive oxygen species (ROS) modulation, while polyaniline (PANI) offers high electrical conductivity and biocompatibility. Integrating these two materials can potentially yield composites with improved antibacterial and anticancer performance through enhanced charge transfer and ROS generation. In this study, PANI/CeO nanocomposites were synthesized by chemical polymerization and investigated for their structural, optical and biological characteristics. The composites were prepared with different weight percentages of CeO, such as 20%, 40%, 60%, and 80%. FTIR analysis confirmed the presence of Ce–O vibrations in the composite matrix. UV–visible absorption spectra showed a shift toward lower wavelengths. The calculated band gap values were 3.2, 3.1, 3.0, and 2.9 eV, based on CeO content. XRD analysis showed a preferred growth along the (111) plane, which indicated the cubic fluorite structure of CeO. The EDAX results confirmed the presence of cerium, oxygen, and carbon in the prepared samples. FE-SEM images showed spherical morphology with CeO well dispersed in the PANI matrix. The I–V measurements revealed non-linear characteristics with an increase in CeO concentration. The antibacterial activity increased against both Staphylococcus aureus and Pseudomonas aeruginosa with higher CeO content. The 80 wt% CeO composites showed the highest inhibition zone of 22 mm. This same composite showed a strong cytotoxic effect on HCT-116 colon cancer cells with an IC₅₀ value of 15.54 μg/mL. PL spectra revealed a broad emission band due to surface defects and a blue peak at 452 nm. The SAED pattern confirmed the crystalline nature of CeO with cubic symmetry.

In this study, micron-sized Taxus powder (TP) was prepared by fine grinding using Taxol-extracted Taxus residue as the raw material, and poly(butylene adipate-co-terephthalate) (PBAT)/polylactic acid (PLA)/TP bio-based composites were subsequently fabricated via melt blending. The influence of TP on the rheological, mechanical, thermal, and functional properties of PBAT/PLA blends was systematically investigated. The results show that TP improves melt-processing behavior and modifies the thermal degradation characteristics of the blends. At low to moderate TP loadings, the elongation at break remains above 200%, while higher TP contents lead to a progressive decline in mechanical performance. Notably, the incorporation of TP induces a gradual transition from hydrophobic to hydrophilic surface behavior, as reflected by a decreasing water contact angle, and significantly accelerates biodegradation. TP also introduces mild but measurable antibacterial activity against Escherichia coli and Staphylococcus aureus . Furthermore, when combined with a nano zinc surface coating, the composites exhibit markedly enhanced antibacterial efficiency through a synergistic surface-mediated effect. This work demonstrates the high-value utilization of Taxus residue as a functional filler and provides an effective strategy for developing biodegradable polymer composites with tunable processing, environmental responsiveness, and antibacterial performance for packaging-related applications.

Flexible supercapacitor devices are the core driving force for the development of advanced energy storage technology. In this paper, novel nano-Cu@Fe₃O₄ spheres were fabricated using a one-pot solvothermal method, and in situ chemical oxidative polymerization of aniline monomer was constructed on the nano-Cu@Fe₃O₄ surface. The positive nano-Cu@Fe₃O₄ electronically adsorbed negative ANI monomers and fabricated conductive Cu@Fe₃O₄/PANI Hybrids (CFP). Interestingly, the as-obtained CFP hybrids possess rich morphology, stable structure, and big surface area, and these CFP hybrids exhibit low solution resistance and good capacitive properties measured by electrochemical tests. Notably, the nano-Cu@Fe₃O₄ spheres induced generation of spiny sea cucumber-like CFP3, effectively improving uniform dispersion and showing the strong synergistic effect of magnetic nano-Cu@Fe₃O₄ and PANI. Especially, the specific capacitance of CFP3 was 869.57 F g⁻¹ at 0.5 A g⁻¹ and the capacitance retention was 85.3% from 0.5 to 10 A g⁻¹. Then the flexible symmetric supercapacitor device was assembled with novel CFP3 as positive and negative electrodes using PVA/H₂SO₄ gel electrolyte, which had 156.67 F g⁻¹ of specific capacitance at 0.5 A g⁻¹ and 13.93 W h kg⁻¹ of energy density at a power density of 100 W kg⁻¹. Thus, CFP hybrids have the potential application as an efficient conductive polymer electrode material for advanced flexible supercapacitors devices.

Herein, we propose a strategy to spatially regulate dynamic bond exchange in epoxy vitrimer by introducing graphite flakes (GFs) fillers with multi-angle orientations (θ = 0°–90°). Through a hot-pressing-induced alignment technique, GFs were arranged in five angular configurations within a disulfide-based vitrimer matrix. Stress relaxation analysis revealed a bidirectional regulatory effect: as θ increased from 0° to 90°, the characteristic relaxation time (τ) at 180°C rose from 17.2 to 28.0 s, while the activation energy (E _a ) decreased from 97.7 to 90.0 kJ/mol. By integrating vector decomposition and Arrhenius kinetics, we established a dual-exponential decay model linking sinθ to E _a and τ, quantitatively describing orientation-dependent dynamics. This work pioneers the spatial manipulation of vitrimer network reconfiguration, offering a paradigm for anisotropic smart materials.

In response to the prominent problems of severe pollution and high difficulty in degradation of dye wastewater. AA monomers were used to construct a high-molecular-weight backbone. Chloroacetic acid was employed for etherification modification of cyclodextrin, introducing abundant -COOH groups onto its molecular skeleton. Further, MWCNT was incorporated as a reinforcing phase into the hydrogel system. The active sites on MWCNT surface form a synergistic adsorption effect with cyclodextrin cavities, significantly broadening the adsorption scope for organic dyes. The structure and morphology of the hydrogels were characterized by infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and x-ray diffractometer (XRD). Different adsorbent dosage, temperature, pH and time were studied. Adsorption properties of Rhodamine B (RhB) dye. The results show that the surface of this cyclodextrin-based porous hydrogel has a well-developed porous network structure. Compared with traditional adsorption materials (such as activated carbon, single cyclodextrin materials and ordinary hydrogels), it has the advantages of larger specific surface area, more abundant active functional groups and higher mass transfer efficiency, and the maximum adsorption capacity of RhB can reach 858.6113 mg/g under optimal conditions. The adsorption process accords with the quasi-second-order kinetic model and Langmuir isothermal model, and belongs to the spontaneous, entropy-increasing and endothermic process. Therefore, the prepared hydrogel adsorbent material possesses the advantages of easy regeneration and efficient reusability, and exhibits great application potential in the purification of RhB from asphalt pavement sewage.