Colloid and Polymer Science最新文献

Plasmonic nanoparticles such as gold nanoparticles exhibit Surface Enhanced Raman Scattering (SERS), enabling highly sensitive Raman spectroscopy for molecular sensing. SERS effect can be strongly enhanced by making plasmonic nanoparticles anisotropic or by assembling them. However, synthesis of such nanoarchitecture requires complicated and time-consuming processes. In this work, we employed a facile immobilization method for spherical plasmonic nanoparticles by incorporating them into the three-dimensional network structure of hydrogels. Nanoparticle aggregation that was induced by an increase in ionic strength was kinetically arrested by in-situ polymerization of hydrogels, thereby preserving small nanoparticle clusters in a gel film. The fabricated composite films were directly applicable as SERS substrates. The composite films containing gold nanoparticle clusters with moderate sizes (around 90 nm in hydrodynamic diameter) demonstrated superior SERS performance. The analytically estimated enhancement factor for the substrates with moderately clustered nanoparticles was approximately 70-fold higher than those with non-clustered nanoparticles. The proposed method for producing moderately clustered nanoparticles enables facile preparation of SERS substrates with superior performance, and moreover, is applicable to various types of nanoparticles to strengthen their properties.

Biochar colloids offer significant potential for soil heavy metal remediation, yet their interfacial interactions with metals and stability regulation mechanisms remain poorly understood. This study investigated the aggregation behavior of peanut shell biochar colloids in Zn²⁺ and Cu²⁺ systems by analyzing hydrodynamic diameter, zeta potential, and critical coagulation concentration (CCC). Results revealed distinct, ion-specific governing mechanisms: (1) In Zn²⁺ System, colloidal stability was governed primarily by electrostatic neutralization with a limited contribution from specific adsorption. At low Zn²⁺ concentrations (0.5–10 mmol/L), rapid aggregation (33 nm/min) was induced via electrostatic neutralization compression of the electrical double layer, with a critical coagulation concentration (CCC) of 3.7 mmol/L. At higher concentrations (15–60 mmol/L), specific adsorption of Zn²⁺ led to charge reversal. (2) In Cu²⁺ System, a unique “aggregation–stability–reaggregation” transition was observed, driven by the synergistic effects of strong specific adsorption, stable complex formation, and electrical double-layer compression. At low Cu²⁺ levels (0.03–0.1 mmol/L), strong specific adsorption triggered rapid aggregation (32 nm/min; CCC of 0.05 mmol/L). At intermediate concentrations (1–10 mmol/L), charge reversal occurred due to the formation of stable complexes, enhancing electrostatic repulsion and resulting in a temporarily stabilized state. At high concentrations (20–300 mmol/L), double-layer compression by NO₃⁻ ions led to re-aggregation (CCC of 9.5 mmol/L; rate: 30 nm/min). This work elucidated how heavy metal ion type and adsorption characteristics differentially governed biochar colloid stability, providing critical theoretical insights for the precision design of biochar-based soil remediation strategies.

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Upcycling waste materials is a key step towards a circular bioeconomy by reducing the reliance on virgin resources, maximizing resources efficiency and minimizing environmental impact. Sustainable materials aim to establish a circular bioeconomy to maximize resources efficiency and promote positive social and environmental impacts. This research investigates the development of eco-friendly thermal insulating sustainable composite using waste coir fibers and waste polypropylene. To enhance fiber-matrix adhesion and improve composite properties, coir fibers underwent alkaline treatment. Compression molding was employed to fabricate coir-fiber reinforced composite sheets with varying coir fiber loadings (30%, 35%, and 40%). The resulting composites exhibited enhanced thermal insulation properties, characterized by reduced thermal conductivity up to 0.10 W/m.K, moderate specific heat capacity up to 1.8844 J/g°.C and lower thermal diffusivity up to 5.28 × 10^− 8 m²/s, as fiber loading was increased. Moreover, the mechanical properties of tensile strength, tensile modulus, Charpy impact strength and drop weight impact strength were improved by 20%, 74%, 146% and 109%, respectively when coir fiber loading was increased from 30% to 40%. Higher mechanical properties and lower thermal properties demonstrate the potential of coir-fiber reinforced composite as a sustainable and high-performance thermal insulation material for domestic applications, contributing to waste upcycling, resource efficiency and environmental sustainability.

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Stable nanocomposite dispersions based on pol(butyl-polymethacrylate) and cationic cellulose nanofibrils (cat-CNFs) were successfully produced through an in-situ miniemulsion polymerization process, utilizing a low amount of cationic surfactant (0.75 wt% relative to the monomer). The study investigated the influence of cat-CNFs content on the colloidal stability and rheological properties of the latex dispersion. Results indicated that the particle size dependence on cat-CNFs content, confirming the critical role of cellulose nanofibrils (CNFs) in the stabilization process during miniemulsion polymerization. Field emission scanning electron microscopy (FE-SEM) revealed the binding of cat-CNFs to polymer particles. Rheological measurements indicate that all dispersions exhibit shear-thinning behavior. The presence of yield stress in dispersions containing more than 2 wt% cat-CNFs suggests the formation of elastic network structures, emphasizing the dominant solid-like characteristics of the dispersion. The thermomechanical, melt-state rheology, and optical properties of nanocomposite films produced by casting and water evaporation were analyzed. Dynamic mechanical analysis (DMA) indicates that the incorporation of cat-CNFs enhances the strength of the films in the rubbery domain up to 4 wt%. However, further increases in CNFs content result in a decline in modulus. Additionally, nanocomposite films produced via the in-situ method demonstrate notable optical properties, highlighting effective dispersion of CNFs. Cat-CNFs-based latexes yield nanocomposite films with excellent mechanical properties and often exhibit a high transparency, making them suitable for applications where aesthetics are important, such as surface coatings and films.

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This study presents the development of sulfobutyl ether-β-cyclodextrin (SBE-β-CD) functionalized polyvinylidene fluoride (PVDF) hollow fiber composite membranes for chiral separation applications. Through surface grafting and comprehensive characterization using scanning electron microscopy, contact angle measurements, and Fourier-transform infrared spectroscopy, we demonstrated the successful immobilization of SBE-β-CD on PVDF membranes. The research systematically investigated and optimized key separation parameters including β-CD derivative selection, SBE-β-CD concentration (45 mM), solution pH (6.0), cross-flow duration, and amlodipine concentration (0.1 mM). The optimized composite membranes exhibited excellent enantioselective performance, achieving 36.5% enantiomeric excess for S-amlodipine with a separation factor of 2.15, attributed to the synergistic effects of electrostatic interactions between sulfobutyl groups and amlodipine enantiomers combined with selective permeation through the hydrophobic cavity structure. This membrane-based separation technology represents a significant advancement in chiral separation methodologies by eliminating the requirement for exogenous chiral selectors while offering operational simplicity, energy efficiency, and scalability. The findings provide both fundamental insights into cyclodextrin-mediated chiral recognition mechanisms and practical solutions for industrial-scale production of enantiomerically pure pharmaceuticals, with potential applications extending beyond amlodipine to other chiral drug separation systems. The work establishes a novel platform technology that bridges the gap between laboratory-scale chiral separation and industrial pharmaceutical manufacturing requirements.

In this study, a grafted benzaldehyde-chitosan/algae/zeolite (CHI_BZD/AL/ZEO) biocomposite matrix was synthesized by hydrothermal heating process followed by freeze-drying process for CHI_BZD/AL/ZEO biocomposite. The adsorptive characteristic CHI_BZD/AL/ZEO towards removal of toxic cationic dye namely brilliant green (BG) was evaluated and optimized by using Box-Behnken Design (BBD) and desirability function approach. BBD test was performed to optimize the independent working variables including A: CHI_BZD/AL/ZEO dosage (0.02–0.1 g/ 0.1 L), B: pH (4–10), and C: adsorption time (20–80 min). Moreover, the best BG removal 96.2% can be achieved at CHI_BZD/AL/ZEO dosage = 0.088 g/100 mL, BG solution pH = 7.6, and adsorption time = 193.8 min. The adsorption isotherm was well presented by Langmuir and the Freundlich models, and the adsorption kinetic was well describe by pseudo-second order (PSO). Thus, CHI_BZD/AL/ZEO shows a maximum adsorption capacity (q_max) of 301.9 mg/g at 25 °C. The BG dye loading onto CHI_BZD/AL/ZEO surface can be assigned to electrostatic forces, H-bonding, Yoshida-H bonding, and n-π stacking. Generally, CHI_BZD/AL/ZEO biocomposite matrix presents itself as promising reusable adsorbent for eliminating toxic cationic dye (BG) from aqueous environment.

Nanoparticles (NPs) provide a potential opportunity to reduce toxicity, optimize drug effects, and properly distribute drugs in the body and/or overcome multidrug resistance. 6-Acetylaminobutyl-9-chloroquino[3,2-b]benzo[1,4]thiazine (QBT) is a tetracyclic, acetylaminobutyl phenothiazine derivative in which one of the benzene rings has been replaced by a quinoline. This compound has shown very promising in vitro and in vivo biological properties. The aim of this study was the spectroscopic analysis of QBT and the development of albumin nanoparticles (HSA-NPs) with encapsulated QBT (QBT-HSA-NPs). This study is a continuation of attempts to encapsulate phenothiazine derivatives in nanoparticles. To investigate the properties of QBT to be encapsulated in HSA nanoparticles, the desolvation method with ethanol as an antisolvent and glutaraldehyde as cross-linking factor were used. UV-vis spectroscopy was used to record absorption spectra in terms of encapsulation efficiency and drug release and the mathematical drug release kinetics mechanism was estimated. Changes in the secondary structure of HSA were verified using circular dichroism (CD) spectropolarimetry. The size and shape of the nanoparticles were ascertained by scanning electron microscopy (SEM). The encapsulation efficiency of obtained nanoparticles was 97.44 ± 0.11%, confirming that QBT can be encapsulated in HSA nanoparticles. SEM examination showed smooth nanoparticles of their size of 101.445 ± 9.907 nm for QBT-HSA-NPs and 92.680 ± 12.797 nm for HSA-NPs. QBT released according to the zero-order mechanism, via QBT diffusion and HSA swelling. The observed changes in the structure of native HSA, influenced by the presence of QBT at the molecular level, may not have a strong influence on the side effects generated in the in vivo system. Despite reports on albumin nanoparticles and QBT, no one has published studies on QBT encapsulation in nanoparticles to date.

Polyethersulfone (PES) membranes are widely used in hemodialysis for their stability and low water adsorption, yet their hydrophobicity promotes protein adsorption and membrane fouling. This study develops an amphiphilic-modified PES membrane (PES/CA-g-AN) grafted with citric acid (hydrophilic) and aniline (hydrophobic) to enhance antifouling performance and solute clearance. Experimental and computational fluid dynamics (CFD) analyses demonstrate that the modified membrane exhibits a 76.43° reduction in water contact angle, indicating significantly improved wettability. The electrostatic attraction between the membrane and protein molecules decreased by approximately 15%, as revealed by density functional theory (DFT). The modified membrane achieved a BSA rejection rate exceeding 97%, along with urea clearance of 85.57% and vitamin B12 clearance of 64.12% under optimized conditions. CFD modeling further quantified the dynamic processes of protein adsorption, pore blockage, and filter cake formation, highlighting a ~ 30% reduction in flux decline compared to pristine PES. These results confirm that amphiphilic modification effectively enhances antifouling properties and solute removal efficiency in hemodialysis membranes.

As the global population continues to increase, environmental pollution, especially water pollution, also escalates. The rise in industrial activities is a significant contributor to this water contamination. Within the industrial sector, a notable source of pollutants is dyes, with one example being thymol blue (TB). TB is frequently employed as a pH indicator in various industries, yet it is recognized for its adverse environmental effects. This research work aims to synthesize a novel binary-metal selenide photocatalyst (CoBaSe NPs) for degradation of TB dye in solar light irradiation. Synthesis of cobalt barium selenide nanocomposite was successfully done via a solvothermal process. The catalyst was embedded in chitosan for easy recovery and to prevent the leaching of catalyst to the environment. FTIR spectra confirmed the formation of newly synthesized nanocomposite (CoBaSe nanoparticles and chitosan-supported cobalt barium selenide microspheres (CoBaSe-CMs). The prominent peaks of cobalt, barium, and selenide confirmed the presence of newly synthesized CoBaSe-CMs nanocomposite in the EDX spectrum. The XRD showed crystalline nature of the NPs. The calculated crystallite size of CoBaSe- NPs was 23.76 nm calculated from the sharpest peak. Based on the analysis of SEM (Fig. 4), 975 μm was the average size of CoBaSe-CMs. The band gap of new photocatalyst was 1.99 eV. The novel photocatalyst microspheres showed best efficiency of photodegradation up to 89% with 0.3 g catalyst dosage, at pH 7, 20 ppm (concentration), and temperature 35–38 °C for 100 min of sunlight exposure. The newly synthesized photocatalyst (CoBaSe-CMs) could be the best option for cleansing dangerous organic dyes different industrial effluents.

Phenolic foam is extensively utilized as a thermal insulation material, and its performance is significantly affected by the ingress of external rainwater. To simulate the material’s environment, we conducted indoor tests to assess its water absorption characteristics under varying water pressure heads. Additionally, we utilized CT scanning to analyze the distribution of water within its pores. The findings indicate that the specimens’ water absorption patterns are quite consistent across different water pressures, with a maximum absorption rate reaching approximately 3200% after reaching a basic level of stabilization. For the novel water-absorbing phenolic material, we processed the CT scan images to enhance clarity and established criteria for determining the gray levels of pore water. It was observed that the phenolic material’s water-absorbing infiltration interface was relatively flat, with localized high infiltration heights at points where large pores interconnected, forming water columns. Microstructural analysis was conducted to elucidate the mechanisms behind the formation of these prominent water columns.