Polymer Bulletin最新文献

The efficiency of adsorption of Sparfloxacin (SPX) onto the surface of synthesized polyaniline coated magnetic nanoparticles (Fe₃O₄@PANI) was studied from aqueous solution under varying experimental conditions. The magnetic nanocomposite was prepared via in-situ oxidative polymerization of aniline in the presence of magnetite (Fe₃O₄) nanoparticles, followed by comprehensive characterization using techniques such as FTIR, XRD, EDX and SEM. A validated spectrophotometric assay was developed for monitoring of SPX drug. The maximum adsorption (%) was obtained at pH = 7.0 for a contact time of 30 min with 0.25 g of Fe₃O₄@PANI. Equilibrium isotherm data were fitted to Freundlich and Langmuir equations, and the later model showed the best fit with Qₒ = 371.19 mgg^− 1. Furthermore, pseudo-first-order and pseudo-second-order kinetic models were used to analyze adsorption kinetics, and it was found that adsorption of the investigated SPX drug followed pseudo-second-order kinetics with R² ≈ 1. Thermodynamic parameters suggested that the adsorption was spontaneous and exothermic. The high adsorption capacity and excellent analytical eco-scale score (AES) of Fe₃O₄@PANI highlight the potential of synthesized Fe₃O₄@PANI as an efficient adsorbent for Sparfloxacin from aqueous solutions.

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Conducting polymers (CP) not only act as an active barrier for corrosive ions but also provide protection to the metal substrate through the redox mechanism. The CP composites were prepared by the in-situ polymerization method. In view of this, the current study describes the synthesis, physico-chemical, physico-mechanical, and corrosion-resistant properties of composites on mild steel (MS) substrates. This research also studied flame resistance properties due to the bio-based tannic acid (TA) and boron trioxide (B₂O₃) in CP composites. The presence of functional groups was examined by FTIR, which represents the major peak of the hydroxyl group, carbonyl group, quinoid, and benzenoid rings in the matrix. The thermal degradation was also studied by TGA. The enhanced corrosion resistance of the composite coatings is attributed to the efficient combination of fillers (B₂O₃ and TA) in conducting matrix poly (o-anisidine) (POA). UL-94 standards in vertical positions were used to examine the flame-retardant characteristics of epoxy-based composites. The physico-mechanical properties of these coatings were evaluated using standard laboratory methods. The corrosion-protective performance of these coatings was investigated using the salt spray test (SST). These studies revealed that composite coatings show far superior thermal stability, physico-mechanical, and corrosion-protective performance than plain epoxy and other such CP-reinforced epoxy coating systems.

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Bacterial cellulose (BC), a biodegradable and biocompatible material, has emerged as a promising wound dressing due to its excellent properties. Moringa oleifera (MO) and Melastoma malabathricum (MM) are traditional herbs rich in antioxidant, anti-inflammatory and antibacterial properties that are beneficial for rapid wound healing, while silver nanoparticles (Ag) is a highly effective antiseptic that is commonly used in medicine. In this study, BC formulated with Ag, MO and MM leaf extracts were characterized by using FTIR, XRD and FESEM-EDX. The water holding capacity, water retention rate and antibacterial activities of BC composites were also evaluated. Based on obtained results, incorporation of MO and MM enhanced the water holding capacity of BC without significantly altering its water retention rate. FTIR analysis confirmed the purity of BC and its crystallinity index was slightly increased in presence of MO, MM and Ag. FESEM-EDX imaging revealed deposition of MO, MM and Ag on the BC matrix. The antibacterial activities of BC composites varied against gram-positive and gram-negative bacteria. Nonetheless, these preliminary findings suggested that BC composites formulated with MO, MM and Ag may hold potential as sustainable wound dressings; however, further comprehensive studies are needed to validate their effectiveness.

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The solubility of polysaccharide gums is a fundamental property dictating their functionality in food, pharmaceutical, cosmetic, and other industrial applications. Despite the critical role of solubility, its assessment lacks a universally accepted and standardized methodology due to challenges in filtering and centrifuging highly viscous gum solutions. The present study introduces a novel, universal, and optimized method for estimating cold-water solubility (CWS) at 25 ± 1 °C, using guar gum (GG), employing the response surface methodology (RSM) as a statistical tool. Three parameters potentially influencing the solubility determination, including concentration, relative centrifugal force (RCF), and centrifugation time, were screened through Tukey’s HSD test and optimized using Box–Behnken design to predict optimum values. The design-predicted optimized values for concentration, RCF, and centrifugation time were 0.5%, 1000 x g, and 10 min, respectively, which yielded a CWS value of 83.85% for GG. The design-predicted CWS was verified experimentally and found within acceptable limits with an error of 2.27%. Furthermore, the optimized parameter values were extended with necessary modifications to assess hot water solubility (HWS) at 80 ± 1 °C. The optimized protocols for CWS and HWS demonstrated flawless applicability to 28 other polysaccharide gums. The study also proposes a solubility-based classification of polysaccharides: insoluble (< 10%), partially soluble (10–70%), and highly soluble (> 70%) at 25 ± 1 °C. This work provides a vital step toward a standardized solubility assay, with direct implications for industry, quality control, and international trade.

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Biodegradable cellulose acetate butyrate (CAB) nanofiber membranes containing Ag-decorated TiO₂ nanowires were fabricated via electrospinning. These nanofibers exhibited UV- blocking and antibacterial properties and can be used as skin contact products such as cosmetic patches and facial masks. TiO₂ is widely used as an inorganic UV-blocking agent in cosmetics. However, crystalline TiO₂ at the nanoscale can generate reactive oxygen species (ROS) and may penetrate into the compromised skin, raising safety concerns. Anatase TiO₂ exhibits much higher photocatalytic activity than rutile. Therefore, one-dimensional (1D) rutile-phase TiO₂ nanowires were selected and synthesized through electrospinning and calcination to reduce penetration risk and minimize ROS generation while maintaining high UV-blocking efficiency. Ag nanoparticles were deposited onto the TiO₂ surface using tannic acid, which served both as a reductant and a stabilizer. This could confer the light independent antibacterial activity. The CAB nanofibers containing Ag/TiO₂ exhibited an average fiber diameter of 715.35 nm and a membrane thickness of 31 μm, achieving a UV-blocking rate of 99.3% and a UPF value of 265 (50+). Antibacterial tests indicated no activity for CAB and TiO₂–CAB nanofibers. In contrast, the Ag/TiO₂–CAB nanofibers exhibited inhibition zones of 2 mm for E. coli and 3 mm for S. aureus which indicates effective antibacterial performances.

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This research aimed to develop a novel biodegradable packaging material using agricultural by-product as a sustainable alternative to petroleum-based packaging. Rice husk and wheat straw were utilized as primary components, with corn starch and wax serving as binders. The resulting samples were evaluated and compared to identify the optimal formulation. Structural, interactional, thermal, and surface properties were examined using Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), and contact angle measurements. SEM revealed rough surfaces with interconnected morphologies, while XRD indicated the presence of cellulose through distinct crystalline peaks. FT-IR spectra showed characteristic peaks corresponding to starch (C–O–C), wax (C–H), and agricultural by-product components (cellulose and lignin). TGA results demonstrated superior thermal stability in rice husk–starch composites. Mechanical testing revealed that wheat straw with starch binder exhibited the highest compression strength under a 30 kN load, whereas rice husk with starch binder showed the greatest flexural strength. Swelling behavior tests indicated minimal weight change, and water absorption tests confirmed that wax-based binders provided the lowest water uptake. Biodegradability assessments validated the eco-friendly nature of all samples. Among the formulations, rice husk with starch binder (RHS) emerged as the most promising in terms of biodegradability, mechanical performance, and thermal stability, aligning well with the goal of sustainable packaging development.

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The fabrication of multilayered nanocomposite vascular grafts is an emerging approach for vascular tissue engineering. In this study, three-layered vascular grafts composed of poly(ε-caprolactone) (PCL), gelatin (Gt), and thermoplastic polyurethane (TPU), incorporating 0–1 wt% zinc oxide nanoparticles (ZnO NPs), were fabricated through layer-by-layer electrospinning. ZnO NPs were synthesized via a microwave-assisted green synthesis method. The antibacterial activity and cytotoxicity of the scaffolds were evaluated to determine the optimum ZnO NPs concentration. The morphological, structural, and mechanical properties of the scaffolds were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD), and dynamic mechanical analysis (DMA). Furthermore, in vitro release behaviour and biodegradability tests were performed on the samples. At the optimum cytocompatible level, the 0.5 wt% ZnO NPs-incorporated scaffold released 0.099 ± 0.004 ppm zinc ions over 72 h in PBS, exhibiting antibacterial activity (29.4 ± 2.1% Escherichia coli, 37.6 ± 4.1% Staphylococcus aureus), and 75 ± 3.85% cell viability in L929 fibroblast cells. SEM analysis indicated that the layers of the obtained scaffolds exhibited homogeneous fibrous structures. The ultimate tensile strength and the Young’s modulus of the scaffolds (incorporating 0–1 wt% ZnO NPs) were found to be in the range of 11.04 ± 0.15–11.32 ± 0.09 MPa and 7.2 ± 0.45–15.6 ± 0.35 MPa, respectively. The findings indicated that the 0.5 wt% ZnO NPs-incorporated scaffold presents the most favorable combination of mechanical strength, antibacterial activity, and biocompatibility, making it a promising candidate for vascular tissue engineering.

Poly(vinyl alcohol) (PVA) composites reinforced with Cissusquadrangularis short fibers and ultra-porous nutmeg husk biochar were developed to address the dual challenge of structural reinforcement and multifunctional performance. The novelty of this work lies in the use of a hybrid natural fiber-biochar system, combined with silane surface treatment, to simultaneously enhance mechanical, thermal, dielectric, and electromagnetic interference (EMI) shielding properties while reducing water uptake. Both untreated and treated series were fabricated to assess the role of interfacial modification. The treated composites consistently outperformed their untreated counterparts due to improved fiber-matrix adhesion, better filler dispersion, and reduced interfacial resistance. Among them, PTB1 delivered the best mechanical performance with tensile and tear strengths of 145 MPa and 123 MPa, respectively, while PTB2 achieved the highest functional properties, including a thermal conductivity of 0.49 W/mK, dielectric permittivity of 4.8 with a dielectric loss of 0.72, and EMI shielding effectiveness up to 31.91 dB in the J-band. Water absorption was also minimized, confirming improved hydrophobicity. Overall, the results demonstrate that combining porous biochar with chemically modified natural fibers offers a novel, sustainable route to high-performance PVA composites with balanced structural and functional capabilities.

Wound healing is a complex physiological process that requires an optimal moist and antibacterial environment to promote tissue regeneration. In this study, chitosan/gelatin (CG) biocomposite films incorporated with different concentrations of Corchorus olitorius (C. olitorius) extract (2.5–10% v/v) were fabricated via the solvent casting method. The effects of extract loading on the structural, thermal, mechanical, optical, and biological characteristics of the films were systematically investigated. The tensile strength of the films decreased from 5.95 ± 1.70 MPa to 1.74 ± 0.20 MPa, while the elongation at break increased up to 110.5 ± 9.8%. Contact angle measurements showed enhanced hydrophilicity with the highest extract content (56.4° ± 4.8°). The incorporation of the extract also led to a notable reduction in transparency (from 7.18% to 2.57%) and a slight decrease in thermal stability. FT-IR spectra confirmed physical interactions, mainly hydrogen bonding, between the polymer matrix and the extract components. Furthermore, the 10% (v/v) C. olitorius-containing film exhibited significant antioxidant activity (80.5% DPPH scavenging) and antibacterial efficiency with inhibition zones of 9 mm against E. coli and S. aureus. These results indicate that the developed chitosan/gelatin/C. olitorius biocomposite films possess favorable physical and biological properties, suggesting their strong potential for wound dressing and biomedical applications.

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Bionanocomposite films comprising chitosan (CS), hydroxyethyl cellulose (HEC), raisin extract (RE) and different ratios of zinc oxide nanoparticles (ZnO-NPs), namely CS/HEC/RE/ZnO bionanocomposites, were formed via casting method. The structural, morphological, mechanical and physical properties of the produced CS/HEC/RE/ZnO bionanocomposite films were characterized using SEM (Scanning Electron Microscope), EDX (Energy Dispersive X-ray), FT-IR (Fourier Transform-Infrared), and UV-Vis (Ultraviolet-Visible) spectrometry. The anti-microbial activity also was assessed against six different strains. The incorporation of ZnO-NPs improved film thickness and swelling ratio, while decreased water solubility properties of the matrix. Concerning the mechanical properties, 4.0% ZnO-NPs exhibited the best elongation at break and tensile strength. In the SEM micrographs, increasing ZnO-NPs content exhibited higher population of white spots and caused a more even, dense, compact, and homogenous film structure. CS/HEC/RE/8%ZnO revealed the highest UV absorbance with a clear peak at 350 nm indicating the incorporated ZnO-NPs. Concerning the antimicrobial activity, CS/HEC/RE/8%ZnO demonstrated the highest antibacterial activity against S. Typhamirum and E. coli. Additionally, CS/HEC/RE/8%ZnO exerts the best antifungal activity against C. albicans with inhibition zone of 23 mm. In conclusion, the acquired bionanocomposite films have excellent structural, morphological, mechanical, and biological properties nominating them for flexible food packaging materials.