Colloid and Polymer Science最新文献

This investigates using graphene oxide (GO) as a nano-reinforcing filler to improve the impact resistance of polydiborosiloxane (PDBS) composite materials reinforced with Kevlar fibers. GO/PDBS/Kevlar composite materials were prepared by combining GO with PDBS and Kevlar. Results indicate that introducing GO and PDBS significantly increases the composite material’s energy absorption capacity. The protective performance of the material was evaluated using quasi-static penetration and low-speed drop impact tests. The maximum penetration force of the 5-layer C-PDBS/Kevlar composite material was 152 N, which is approximately 111% higher than pure Kevlar fabric (72 N). Low-speed drop impact tests demonstrated that adding GO effectively improves the material’s response under dynamic impact conditions. The peak force of a 10-layer C-PDBS/Kevlar composite material increased from 1620 N to 2294 N, a 41.6% increase. These results demonstrate that C-PDBS significantly promotes the energy dissipation mechanism of composite fabrics, enabling C-PDBS/Kevlar composites to exhibit excellent impact resistance.

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In this study, the rheological properties of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) were modified by the addition of poly(ε-caprolactone) (PCL) or triethyl citrate. Triethyl citrate was found to be miscible with PHBHHx and act as a plasticizer. As theoretically predicted, the shear viscosity of plasticized PHBHHx clearly decreased in the low shear rate region. In contrast, PCL was immiscible with PHBHHx, and the PHBHHx/PCL blends showed the phase-separated structure. Although the decreases in the oscillatory shear moduli in the linear viscoelastic region were limited, the steady-state shear viscosity greatly decreased by the addition of PCL in a wide range of the shear rate. Furthermore, the addition of PCL also enhanced the crystallization rate of PHBHHx. This technique will be attractive in industry because the molecular weight of PHBHHx should be high to meet the requirements of the mechanical properties in the solid state.

Chemical fuel-driven hydrogels characterized by a controllable phase transition, have garnered significant attention over the past decades due to their tunable lifetimes. Here, we introduced a novel temporally programmed hydrogel synthesized from polyvinyl alcohol (PVA) and boric acid (B(OH)₃) using sodium hydroxide (NaOH) and methyl lactate as chemical fuels. The introduction of these fuels triggers the formation of dynamic covalent borate ester bonds between PVA and B(OH)₃ under alkaline conditions, resulting in the development of an elastic hydrogel with a storage modulus of ~ 130 Pa and a peak apparent viscosity exceeding 10⁷ mPa·s at low shear rates, accompanied by pronounced shear-thinning behavior. As ML gradually hydrolyzes, NaOH is consumed, leading to a controlled decrease in pH from 9.03 to 5.26 over 3200 min. This pH reduction induces the dissociation of borate ester bonds, reverting the hydrogel back to its sol state. The phase transition is highly programmable, with its lifetime (ranging from 1 to 80 h) precisely adjustable by varying the concentrations of NaOH and ML, as well as the temperature. Specifically, the duration of the gel phase increases with higher NaOH concentrations, while it decreases with greater ML content or elevated temperatures. Notably, the sol-to-gel-to-sol transition can be programmed by modifying the composition of the chemical fuels or by adjusting the temperature. Moreover, the hydrogel demonstrates remarkable reversibility and mechanical stability, retaining over 90% of its initial modulus after three cycles of fuel regeneration. Given these unique characteristics, this polymer hydrogel holds significant promise for applications in information security and the immobilization of quartz sand.

The Nymphaea hybrid stems, as industrially harvested waste parts of Nymphaea hybrid, have received limited attention, particularly as a source of bioactive polysaccharides. Enzymatic-assisted Flash Extraction (EAFE) for effective polysaccharide extraction from Nymphaea hybrid stems were optimized using response surface techniques, and the optimal parameters were established as follows: A-Enzymatic hydrolysis temperature(50 ℃), B-pH value(5), and C-Flash extraction time(70 s), yielding 216 ± 1.24 mg/g of crude Nymphaea hybrid stems polysaccharide (NHSP). Two fractions from NHSP, NHSP-1 (10.3 kDa) and NHSP-2 (17.7 kDa), were isolated and refined using DEAE-52 and Sephadex G-100. NHSP-1 is a glucose-based polymer, while NHSP-2 is a heteropolysaccharide including nine monosaccharides. Differences were observed in their surface morphology, with NHSP-1 presenting a lamellar spherical architecture and NHSP-2 showing a loose, web-like structure. Bioactivity assays revealed that NHSPs possess potential antioxidant, anti-inflammatory, and moisture retention properties. However, the distinct structural features of NHSP-1 and NHSP-2 endow them with different efficacy properties. These findings offer theoretical support for the optimization of extraction efficiency and refined utilization of NHSP, offering potential for creating targeted functional ingredients in nutraceutical and cosmetic applications.

Cr(VI) poses a significant threat to the global aquatic environment’s safety due to its high toxicity and cell permeability. Therefore, the development of novel and efficient adsorbents for Cr(VI) removal from aqueous solutions is of great importance. In this study, three N-containing organic compounds were selected to modify laponite (LAP) via three strategies: copolymerization, surface modification, and interlayer intercalation, resulting in three modified adsorbents: P(DVB-VIm)/LAP, PEI/LAP, and PANI/LAP. Characterization of the modified adsorbents was performed using FTIR, XRD, BET, SEM, and TEM. Compared with LAP, the P(DVB-VIm)/LAP (10.623 nm), PEI/LAP (12.877 nm), and PANI/LAP (12.896 nm) exhibited larger pore sizes. Under pH 2, the maximum Cr(VI) adsorption capacities of P(DVB-VIm)/LAP, PEI/LAP, and PANI/LAP were 59.38, 56.31, and 55.77 mg·g^− 1, respectively. XPS analysis of the adsorbents after Cr(VI) adsorption was conducted to elucidate the adsorption mechanism. The results indicated that the three composites primarily removed Cr(VI) through electrostatic adsorption and reduction, while complexation and pore adsorption also contributed to a certain extent. By combining zeta potential analysis, the effect of pH variation on the performance of three adsorbents was investigated; there pH_PZC values are 5.31, 6.71, and 6.55, respectively. The adsorption efficiency remained above 50% even after at least 9 consecutive adsorption-desorption cycles. Kinetic studies revealed that the Cr(VI) adsorption process of the three composites followed the pseudo-second-order kinetic model. This study has revealed that organo-N modified laponite holds promising application prospects in the field of Cr(VI) removal.

This study explores enhancement potential of calcium chloride hexahydrate (CaCl₂0.6 H₂O), a phase change material (PCM), using stable single-step silica nanofluids and natural surfactant derived from biomass for thermal energy storage (TES) applications. Silica nanofluids enhance thermal conductivity, facilitating more efficient heat transfer during the phase transition process. Additionally, the incorporation of biomass-extracted surfactants improves the dispersion stability of nanofluid and enhances both thermal reliability and cycling stability. Thermal analysis of the natural surfactant demonstrated a melting point of 11.95 °C, as determined by differential scanning calorimetry, while thermogravimetric analysis indicated a moderate weight loss of approximately 12%. This study examines the influence of natural surfactant combined with varying concentrations of silica nanofluid (0.5, 1, and 1.5 wt%) on the thermal stability of the nano-enhanced phase change material (n-PCM). Among the tested concentrations, the lowest loading of 0.5 wt% (n-PCM1) demonstrated superior thermal performance, indicating its effectiveness in enhancing thermal stability. Experimental results demonstrated substantial improvements in thermal storage capacity, phase transition stability, and reusability, highlighting the potential of enhanced CaCl₂.6H₂O PCM for scalable, sustainable TES systems with significant improvements in melting point (51.35 °C), and thermal conductivity (0.64 W/m.K) along with minimal weight loss in TGA analysis whereas, n-PCM2 and n-PCM3 exhibited additional weight losses of 11% and 21.77%, respectively. This sustainable modification approach not only minimized reliance on synthetic additives but also leveraged eco-friendly materials, aligning with green chemistry principles essential for TES applications. This eco-friendly advancement in PCM technology paves the way for improved TES materials critical for renewable energy systems, waste heat recovery, and building energy efficiency.

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Energy storage, catalysis, and sensing have all showed a great deal of interest in the potential uses of Copper oxide (CuO) and nickel oxide (NiO), which is well-known for its broad band gap, outstanding thermal stability, and electrochemical qualities. In this work, Cu/PVDF-HFP and Ni/PVDF-HFP nanofibers were synthesized via electrospinning followed by thermal calcination. XRD confirmed the formation of monoclinic CuO and cubic NiO phases with average crystallite sizes of 8.09 nm and 37.06 nm, and lattice strains of 0.0014 × 10^− 6and 0.0051 × 10^− 6, respectively. Raman spectra further validated the structural phases and confirmed the presence of reduced graphene oxide (rGO) within the calcined composites. SEM images revealed interconnected and dense CuO and NiO networks, while UV–Vis analysis indicated direct band gaps of 2.4 eV (CuO) and 1.84 eV (NiO). The calculated Urbach energies were 1.45 eV and 1.80 eV for Cu/PVDF-HFP and Ni/PVDF-HFP, respectively. The obtained nanocomposites exhibit excellent structural stability and strong visible-light absorption, making them suitable for gas sensing, photocatalysis, and advanced energy storage applications. This facile synthesis route demonstrates a scalable pathway to engineer multifunctional metal oxide–polymer composites for next-generation electrochemical devices.

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The management of sludge waste residue remains a critical environmental challenge, as improper disposal can contaminate major water bodies, disrupt aquatic ecosystems, and pose risks to human health. The sludge samples in river water and seawater exhibited distinct negative surface charges, as indicated by their zeta potential values, which strongly influence their stability and interaction with charged materials. In this work, a novel surface-active natural rubber latex (NRL) film was developed via optimized compounding and curing techniques to capture sludge particles through electrostatic and interfacial interactions. The formulation introduces intrinsic amphiphilic and protein-rich functionalities within the NRL matrix, enabling spontaneous adsorption of charged particulates without the need for external energy input. Fourier-transform infrared spectroscopy (FTIR) confirmed the presence of amine, protein, and peptide groups on the film surface after sludge interaction, validating the adsorption and surface entrapment mechanisms. The sludge removal efficiency was significantly enhanced in the presence of polyaluminum chloride (PACl), which served as a synergistic coagulant, enlarging sludge particle size and reducing zeta potential to promote aggregation and adhesion onto the NRL film. The combined NRL–PACl system demonstrates a novel, green, and reusable platform for passive sludge remediation, showing potential scalability for wastewater treatment in saline and freshwater environments.

The upcycling of eggshells as fillers in biopolymer matrices offers a sustainable pathway for developing eco-friendly biocomposites, aligning with the current research trend of producing biopolymer films from renewable feedstocks. In this study, biodegradable films based on regenerated cellulose obtained from banana stem were fabricated via the solution casting technique, incorporating varying concentrations of eggshell powder (0–3 wt %). The resulting films were evaluated through thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), mechanical testing, water absorption, and water contact angle analysis. FTIR analysis confirmed the presence of electrostatic interactions between calcium ions and hydroxyl groups, as well as hydrogen bonds between carbonate groups and cellulose hydroxyl groups. EDX results demonstrated an increasing calcium with increasing filler content. However, SEM micrographs revealed that filler dispersion uniformity decreased at higher loadings, as evidenced by increased surface roughness in the 3% filler-loaded films. Thermal analysis indicated that at 3% filler, the thermally stable calcium carbonate particles hindered heat transfer to the cellulose matrix, thereby elevating both the onset and endset degradation temperatures. This enhanced thermal stability was further supported by substantial char residue of 55% at 760 °C. From a mechanical perspective, incorporation of 2% calcium carbonate yielded the highest tensile strength of 35 MPa, representing a 64% improvement compared to neat film. These findings highlight the potential of eggshells as an effective reinforcing agent for enhancing functional properties of thermally stable regenerated cellulose-based films, thereby promoting the development of environmentally sustainable solutions.

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This investigation explores the development of a photothermal-responsive pesticide delivery system using composite beads composed of sodium alginate (SA), yeast (YS), polyvinyl alcohol (PVA), citric acid (CA), and detonation nanodiamond (DND). The beads were synthesized via ionotropic gelation and characterized for morphology, thermal stability, and functional group content. SA formed the primary biodegradable matrix, while DND significantly enhanced photothermal conversion efficiency and mechanical strength. YS mitigated drying shrinkage and improved water retention capacity, and CA enhanced structural stability. The release of fulvic acid (FA) as a model pesticide was evaluated under light exposure, demonstrating a controlled release behavior driven by the photothermal-responsive effect of DND. The release kinetics were best described by the Korsmeyer-Peppas model, which directly evidences the transition from relaxation-dominated to diffusion-relaxation-coupled release, driven by the photothermal-responsive effect of DND. This study provides a promising strategy for the controlled release of pesticides in agricultural applications, leveraging the photothermal-responsive properties of DND, the structural matrix provided by SA, the morphological stability imparted by YS, and the protective coating of CA.

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