Colloid and Polymer Science最新文献

One way to mitigate microplastic pollution from pharmaceutical and cosmetic products is to develop nature-based ‘green’ microcapsules. This study involves in situ microencapsulation of therapeutic tea tree essential oil by brown algae-derived alginate biopolymer using classic external ionotropic gelation. The effects of type of divalent crosslinkers (calcium and barium ions), presence/absence of surfactant in oil-in-water (o/w) emulsion and molecular weight of alginate were investigated using gravimetry, scanning electron microscopy (SEM), shear rheometry, ultraviolet (UV) and infrared spectroscopy. Microcapsules were ~ 1 mm in diameter. Barium chloride crosslinker showed highest gel strength (8396 ± 306 Pa) and large pores on surface (59.9 ± 9.1 µm). Presence of surfactant lowered the gel strength (182.6 ± 100.5 Pa) and had smaller pore size (20.3 ± 2.6 µm). Microcapsules with no surfactant, calcium chloride crosslinker and low viscosity alginate showed optimum gel strength (3620.8 ± 141.5 Pa) and smooth surface. An interplay exists between loading capacity (proportional to pore size) and encapsulation efficiency (compromised by surface oil and water-soluble oil components). Life cycle analysis (LCA) shows significant reduction in global warming and ecotoxicity. This project supports eight Sustainable Development Goals (SDG) of United Nations and promotes blue economy.

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Gene therapy holds promise for a wide range of diseases, including Alzheimer’s, diabetes, and cancer, and requires the efficient transfer of nucleic acids into cells. However, transfection in primary cells is still problematic and requires the development of new transfection agents. Poly (β-amino ester) (PBAE) has attracted great attention in transfection research due to their low toxicity, high gene loading capacity, endosomal escape ability, and biodegradability properties. In this study, two new PBAEs with different molecular weights are synthesized that could provide high viability and transfection efficiency in primary cells. They are characterized using FTIR and ¹H NMR analysis. GPC-SEC system is also used to calculate the average molecular weight (M_w) and polydispersity index. PBAE nanoparticle preparation is carried out using the nanoprecipitation technique. The gene loading capacity, protective ability against nuclease degradation, and proton buffering capacity of nanoparticles are determined. Additionally, the morphology of PBAE_A:pEGFN1 complexes was investigated by STEM analysis. Finally, their cytotoxicity and transfection efficiency in primary ovine fibroblast (POF) cells are also investigated. The results reveal that the new PBAE with higher M_w achieves quite high transfection efficiency of about 87% and did not show any cytotoxic effects on these cells. These findings suggest that PBAE is a promising option to achieve high transfection efficiency in primary cells.

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This study focused on the development and characterization of chlorquinaldol (CQD)-loaded nanogels for effective topical application. CQD, a hydrophobic antimicrobial agent, was encapsulated using polymers like carbopol 940 and gellan gum through high-pressure homogenization to enhance its solubility and stability. The prepared nanogels exhibited a particle size of 143.56 ± 2.34 nm and a zeta potential of − 0.1 mV, ensuring stability and uniform dispersion. The pH of the formulation was optimized to 6.43, which is compatible with skin applications. The nanogels demonstrated sustained drug release, achieving 87.09 ± 1.08% release over 48 h, following first-order kinetics. Antimicrobial studies against Staphylococcus aureus and Pseudomonas aeruginosa showed superior efficacy, with zones of inhibition measuring 20.5 ± 1.2 mm and 18.3 ± 1.4 mm, respectively, compared to free CQD (15.2 ± 1.1 mm and 13.5 ± 1.0 mm). Furthermore, the nanogel formulations exhibited excellent spreadability (13.3 g cm/s) and were non-irritant, as confirmed by skin irritation tests on animal models. These findings suggest that CQD-loaded nanogels are a promising platform for enhanced topical drug delivery, offering sustained release, improved stability, and superior antimicrobial activity.

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Polymer silicone elastomers have attracted extensive attention in fields such as human- computer interaction and health monitoring. However, traditional silicone materials are prone to irreversible damage during usage, and most of them can only self-healing under ultraviolet light of specific unfriendly wavelengths. This is harmful to the user’s health and restricts their application in multi-band exposure scenarios. Hence, there is an urgent necessity to explore materials that can self-healing under diverse conditions. In this research, carbon nanotubes (CNTs) were integrated as a photothermal conversion agent into self-healing poly(siloxane-urethane) (PSiUe) materials to fabricate a poly(siloxane-urethane)-carbon nanotube composite (PSiUe-CNTs) with multi-band self-healing properties. The impacts of different CNTs contents on the mechanical properties, self-healing properties, and thermal stability of the PSiUe-CNTs composites were investigated. By analyzing the mechanical properties of the composites with different CNTs content, it is found that the composites exhibit excellent mechanical properties when the CNTs content is 8%. Further analysis of mechanical properties before and after self-healing showed that PSiUe-CNTs were in ultraviolet light (365 nm), visible light (400–760 nm), near-infrared light (0.78–1.4 μm), and far-infrared light (25–1000 μm) under exposure can reach more than 90% self-healing efficiency in 6-h repair time, which achieve multi-band self-healing. By comparing the results of the analysis of the elements near the scratch, it is proved that the content of N, O, and Fe elements has been increased to different degrees. In addition, the recyclability analysis showed that the recyclability of the composites was excellent, with recovery efficiency above 90%. Therefore, this unique multi-stimulus-responsive self-healing polymer material can fulfill the requirements of various application scenarios, especially those closer to sunlight, and shows broad application prospects.

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This research focuses on the removal of a toxic pollutant viz. methylene blue (MB) from polluted water. Xanthan gum (XGm) was employed as the base polymer, while acrylamide (AAm) and methacrylic acid (MAA) were used as monomers. N-hydroxymethyl acrylamide (NHMA) served as the crosslinking agent in the free-radical polymerization process to synthesize the hydrogel XGmMAN. Three hydrogel variants were developed by varying the concentration of NHMA. To enhance the catalytic performance, copper oxide (CuO) nanoparticles were integrated into the hydrogels via the sol–gel method, forming a nanocomposite (XGmMAN@CuO NCs) that acted as catalysts for the reduction of MB dye. These materials were thoroughly characterized using techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), gel permeation chromatography (GPC), thermogravimetric analysis (TGA), point of zero charge (ΔpHpzc), and scanning electron microscopy (SEM). The synthesized XGmMAN-3@CuO NCs achieved the highest dye removal efficiency of 98.65% at an optimal pH of 7, with a maximum adsorption capacity of 144.50 mg/g. Additional experiments investigated the effects of adsorbent dosage, pH, contact time, temperature, and dye concentration. The adsorption behavior followed the Langmuir isotherm model, while kinetic studies indicated a pseudo-second-order mechanism. Thermodynamic analysis revealed negative ΔG values, confirming that the adsorption process was spontaneous. The adsorbed MB dye was converted to a less harmful colorless substance leuco-methylene blue using NaBH₄ as a reducing agent. The catalytic activity of the nanocomposite toward MB reduction was assessed through UV–visible spectrophotometry, keeping the amount of NaBH₄ constant while varying the pH levels. The hydrogel nanocomposites showed excellent catalytic efficiency at moderate NaBH₄ concentrations, exhibiting its effectiveness for removal of MB dye from synthetic wastewater. Furthermore, the XGmMAN-3 hydrogel exhibited excellent reusability, achieving a desorption efficiency of 96.62% and maintaining consistent performance across five consecutive adsorption–desorption cycles.

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The contamination of water, especially through the presence of toxic and carcinogenic hexavalent chromium (Cr(VI)), represents a significant global challenge, threatening both human health and ecosystems. Hexavalent chromium presents considerable threats, including organ damage, genetic mutations, and carcinogenic effects, underscoring importance for its effective removal (down to 10 µg/L) from wastewater. Adsorption materials show significant promise in wastewater remediation. By in situ polymerizing pyrrole on CoFe₂O₄ nanoparticles, a polypyrrole-coated cobalt ferrite (PPy@CoFe₂O₄) magnetic nanosorbent is synthesized to achieve effective removal of Cr(VI). XRD data corroborated the findings of the SEM examination, which showed spherical nanoparticles with diameters of about 50 nm. Spinel ferrite production was suggested by the FTIR spectra, which showed clear peaks in the 400–600 cm⁻¹ region, confirming the evidence of M–O bonds. The investigation of zeta potential revealed that the polypyrrole-coated cobalt ferrite nanoparticles have a positive surface charge in an acidic medium and a negative surface charge in alkaline media. The adsorption behavior aligned with a pseudo-second-order kinetic model. The adsorption isotherms were accurately represented by the Langmuir model. PPy/CoFe₂O₄ demonstrates a maximal monolayer adsorption capacity of 369.6 mg g⁻¹ under optimum conditions (330 K temperature, 60.0 mg adsorbent dose, and pH 2.0). The removal efficiency was still higher than 91% following the five adsorption–desorption cycles. The adsorption of Cr(VI) onto PPy/CoFe₂O₄ takes place spontaneously, as indicated by a negative ΔG°. The results indicate that the PPy/CoFe₂O₄ composite functions as a highly efficient adsorbent, showcasing extensive applicability in the treatment of wastewater contaminated with heavy metal ions.

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This study presents a novel approach to enhancing the performance of ethylene-propylene-diene monomer (EPDM) and acrylonitrile-butadiene rubber (NBR) composites by reinforcing them with graphene oxide (GO) modified using 4,4-diphenylmethane diisocyanate (MDI). While GO has been widely used as a nanofiller in rubber matrices, the use of MDI-functionalized GO (MDI-GO) in EPDM/NBR blends has not been previously reported. The modified nanofiller was incorporated using an open-mill mixer, and its effect on composite morphology was examined via field emission scanning electron microscopy. The study systematically evaluated the cure characteristics, mechanical properties, compression set, abrasion resistance, and swelling resistance of the composites. Results showed that EPDM/NBR/MDI-GO composites outperformed both unfilled and GO-filled composites. Notably, the MDI-GO-reinforced composite achieved a 137% increase in tensile strength, 59% in stress at 100% elongation, and 101% in tear strength compared to the base compound. Abrasion resistance also improved with increasing MDI-GO content, attributed to enhanced interfacial interaction and filler dispersion. These findings demonstrate the effectiveness of MDI surface functionalization in significantly improving rubber nanocomposite performance.

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The purpose of the present study was to explore the possibility of Mangifera indica (MI) residue as a novel source of polysaccharides by optimizing the extraction procedure and characterizing the resulting product. The polysaccharide content of the powdered kernels of MI was extracted with the aid of response surface methodology (RSM) to optimize the process. Box-Behnken design (BBD) was employed to improve the extraction variables, including centrifugation time (20 min) and force (6800 × g), number of extraction cycles (2), and ratio of water to raw material (18), where the obtained yield which was about 59.65 ± 1.09%. Then, the morphological and physicochemical properties of the extracted polysaccharide were studied using field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared (FTIR) spectroscopy. Antimicrobial activities of the extract shown ideal 13.4 ± 0.21 and 10.8 ± 0.15 mm for gram-positive and 13.3 ± 0.43 mm of gram-negative bacteria, respectively. This shows that the ability of MI to reduce DPPH radicals was highly concentration-dependent, which suggests that the particles are very strong antioxidant (53.0 ± 5.13). From the cell viability study exhibits the proliferation of 3T3 mouse fibroblast cells on the surface of polysaccharide suggest that was non-toxic with the concentration ranges from 5 to 50 µg mL⁻¹. Moreover, MI-derived polysaccharides are sustainable, effective alternatives to traditional polysaccharides for widespread applications in homeostatic agent, absorbent, antimicrobial therapy, antioxidant formulations, and wound care.

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To improve the use value and economic applicability of building components, the mechanism of performance improvement of epoxy crack repair agent was explored. The influence mechanism of diglycidyl ether (DGEBA) on the epoxy system was revealed through macroscopic experiments and microscopic molecular dynamics (MD) simulation. The glass transition temperature (Tg) of the epoxy system was obtained by differential scanning calorimetry (DSC). The mechanical properties of the epoxy system were characterized by tensile, bending, and compression tests. On this basis, the shrinkage and flexural properties of mortar bonded specimens were tested to characterize their engineering adaptability. The static mechanical properties, concentration distribution, mean square displacement (MSD), fractional free volume (FFV), radial distribution function (RDF), the distribution of H bonds, and cohesive energy density (CED) of the simulated system were analyzed by MD simulation. It was found that the content of DGEBA affected the comprehensive properties of epoxy. When DGEBA: m-PDA = 5:1, the mechanical and thermodynamic properties of epoxy are significantly improved. DGEBA can significantly improve the stability of interatomic bonding of epoxy systems, reduce the movement ability of molecular chains, make the distribution of molecular chains more concentrated, improve the packing density of the system, thus greatly improving the elasticity and stiffness of the system, and enhance the mechanical properties. This method provides a new way to repair cracks in building components.

This study presents a novel polymeric delivery system for nutraceuticals, specifically resveratrol, using a pH-sensitive method for colon-specific release. The polymeric carrier system consists of aminated gellan gum (AGG) conjugated with coumaric acid (CA) and alginate (Alg), forming hydrogel beads that protect the encapsulated components from the acidic gastric environment while enabling targeted release in the small intestine. Experimental findings demonstrate a pronounced pH-responsive swelling behaviour and drug release of the hydrogel beads, effectively restraining the release of resveratrol at gastric pH and facilitating a controlled release at the intestinal pH of 7.4. The release exponents from the kinetic analysis using different models indicates a non-Fickian diffusion mechanism governing the release of resveratrol from the polymer matrix. Furthermore, the synthesised gel beads exhibit high biocompatibility, as demonstrated with the Caco-2 cell line. Notably, the phenol-grafted polymer system for the delivery of nutraceutical has not been reported previously and this study marks the first report. The developed hydrogel beads hold significant promise as an effective drug delivery vehicle for nutraceutical applications, potentially improving the therapeutic efficacy of encapsulated compounds.

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