Search Results (1,582)

Curcuminoids from Curcuma longa L. (curcumin, demethoxycurcumin, bisdemethoxycurcumin) are attractive bioactives yet constrained by low water solubility and chemical instability. Herein, we introduce a Supramolecular Deep Eutectic Solvent (SupraDES) as a “Janus” green platform, combining extraction and stabilization with a subsequent solvent-to-material strategy. Eight NaDES/SupraDES formulations based on choline chloride (ChCl) or betaine with glycerol (Gly) or citric acid (CitA), with/without β-cyclodextrin (βCD), were assessed. The extinction coefficients of the most promising solvents were extrapolated at 425 nm for the UV–vis quantification of curcuminoids, to determine extraction performance. The SupraDES ChCl:Gly:βCD gave the best performance during the first solvent screening, improving at the same time the bioactive stability (after 30-day, 47.5% loss vs. 62.8% of ChCl:Gly alone). Subsequent microwave-assisted extraction (MAE) optimization identified 80 °C as the optimal process temperature, with near-equilibrium reached within 15 min (3139.4 µgCurc/gEXT). Peleg modelling (R² = 0.997) indicated a fast extraction rate and limited benefit from longer residence times. Finally, the curcuminoid-loaded SupraDES was incorporated into polyvinyl alcohol (PVA) networks crosslinked with CitA and 2,5-bis(hydroxymethyl)furan (BHMF); thermal analysis confirmed the formation of a stable crosslinked structure. To the best of our knowledge, this is the first report of a βCD-based SupraDES acting as a Janus platform that couples supramolecular extraction of lipophilic bioactives with their direct incorporation into bio-based polymeric materials, exemplifying an integrated green chemistry approach aligned with circular bioeconomy principles. Full article

The application of silk sericin as a polymeric biomaterial has recently gained interest, although its film was found to be fragile, exhibiting brittleness when subjected to relatively slight stress, and it also displayed higher water solubility. This study focused on the enhanced physico-mechanical properties of the three films obtained by the crosslinking of sericin protein from three silkworm cocoons with poly (vinyl alcohol) (PVA) to reduce phase separation and solubilization of the films by promoting miscibility between sericin and PVA. The findings demonstrated how crosslinking with glutaraldehyde enhanced thermal stability and tensile strength and controlled the solubility of the three sericin–PVA films. The sericin from G. postica, G. rufobrunnea, and Argema mimosae is composed of serine, aspartic acid, and glutamic acid, which make up 80% of the total polar amino acids. X-ray diffraction (XRD) patterns showed that sericin–PVA films have semicrystalline features, representing amorphous and crystalline regions. The XRD results also indicated that the Saturniidae sericin–PVA film (Sat-SPF), Gonometa postica sericin–PVA film (GP-SPF), and Gonometa rufobrunnea sericin–PVA film (GR-SPF) have crystallinity percentages of 66.4%, 55.9%, and 17.7%, respectively. The moisture vapor transmission rate (MVTR) values observed in this study ranged from 991.2 to 5160 g/m²/24 h, indicating that these films can effectively regulate moisture levels in wounds. The swelling capacity of the three sericin–PVA composite films depends on the crosslinking density of their structures and was also found to be sensitive to the pH of the aqueous media, demonstrating their hydrophilic nature and potential use in drug delivery systems. The water vapor permeability of sericin–PVA films increased with higher environmental relative humidity (RH) and moisture content within the films. The elongation at break for GP-SPF (107.2% ± 3.1) and Sat-SPF (73.0% ± 4.1) was significantly higher than in GR-SPF (29.3% ± 2.3). However, their tensile strength and elastic modulus were lower than those of GR-SPF. These results show that the number of polar groups (amino and hydroxyl groups) from both sericin and PVA influences all the properties of the sericin–PVA composite films. The three sericin–PVA solutions were found to have antibacterial efficacy against three Gram-positive and one Gram-negative bacteria over 24 h. Scanning electron microscopy (SEM) images revealed a rough surface with a granular network pattern, which supports the potential use of sericin–PVA films for cell adhesion and proliferation, which are essential for biomedical wound dressing applications. Full article

To meet the demand for superabsorbent, long-acting water-retentive, and recyclable hydrogel materials in landscaping applications, a series of AG-PAA/DA composite hydrogels were prepared using agarose (AG) and polyacrylic acid (PAA) as the network backbone, incorporating different mass fractions (2–30%) of dopamine (DA) via free radical polymerization initiated by ultraviolet light. The effects of DA content on the chemical structure, morphology, thermal stability, mechanical properties, water retention behavior, swelling kinetics, and cyclic water absorption–desorption performance were systematically investigated. The results show that DA is successfully integrated into the AG-PAA network through hydrogen bonding, electrostatic interactions, and covalent crosslinking, forming an amorphous homogeneous system. Thermal stability increases with DA content (residual mass at 800 °C rises from 77% to 88%). Mechanical properties exhibit a trend of increasing stress but decreasing strain, with optimal toughness (~670 kJ/m³) achieved at 10 wt% DA. Water retention performance is environment-dependent: in pure water, water retention increases with higher DA content, whereas in soil the opposite trend is observed. The kinetics of swelling conform to the pseudo-second-order model. The hydrogel with 10 wt% DA exhibits an equilibrium water absorption of 50 g/g in 0.9% saline solution and 1060 g/g in deionized water, and after 20 swelling–deswelling cycles the capacity retention fluctuates by less than 5%, demonstrating excellent cyclic stability. Considering all properties, AG-PAA/DA-10 is identified as the optimal formulation. This hydrogel combines high water absorption capacity, good environmental adaptability, and recyclability, showing great promise for water-saving irrigation in landscaping. Full article

Bacteria-infected wounds remain a major global biomedical challenge, with persistent inflammation and the lack of real-time monitoring significantly impairing wound healing. To address the limitations of conventional dressings, which often provide single-function and static treatment, we developed a multifunctional HP@CGA hydrogel based on methacrylated hyaluronic acid (HA-MA) and polyvinyl alcohol (PVA), incorporating chlorogenic acid (CGA) and bromothymol blue (BTB). In the presence of a photoinitiator, the methacryloyl groups of HA-MA undergo UV-induced free-radical polymerization to form a covalently crosslinked network, while PVA chains interact with the HA-MA backbone through hydrogen bonding and physical entanglement, resulting in a stable interpenetrating double-network structure. This integrated “treatment + monitoring” design offers a low-cost and convenient alternative to conventional wound dressings and separate sensing systems. Material characterization and preliminary experiments demonstrated that the hydrogel enabled visual pH detection within the range of 6.0–8.0 through distinct color changes. In addition, it exhibited excellent antibacterial activity, achieving antibacterial rates of 99.9% ± 0.08% against both S. aureus and E. coli. These results demonstrate the multifunctional performance of the HP@CGA hydrogel, including bacterial inhibition, inflammation alleviation, and real-time wound pH feedback, thereby providing a favorable microenvironment for infected wound healing. This work highlights the potential of HP@CGA hydrogel for precise and intelligent wound care. Full article

Silica dispersion in rubber matrices remains a critical issue due to the polarity mismatch between silica and the rubber phase. This study aimed to synthesize functionalized liquid polyisoprene rubber (F-LIR) and evaluate its role in improving the interfacial interaction between silica and solution styrene–butadiene rubber (SSBR). F-LIR was synthesized by introducing an alkoxysilane-containing functionalizing agent at the termination stage of anionic polymerization. Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance spectroscopy (¹H-NMR) were used to confirm the successful introduction of silyl groups at the chain ends of liquid polyisoprene. The optimal loading of F-LIR in SSBR was evaluated through bound rubber content, dynamic mechanical analysis, and mechanical performance testing. The results demonstrated that F-LIR improved the tensile strength, modulus at 300% elongation, and bound rubber content of SSBR composites. These enhancements are attributed to the reaction between the silyl groups of F-LIR and surface hydroxyl groups of silica, together with the co-crosslinking interaction between F-LIR and SSBR. The composites containing 4 phr F-LIR exhibited the best overall balance of properties. This study provides a novel method for synthesizing F-LIR, which bridges silica and the rubber matrix by enhanced filler–rubber interactions at the filler–rubber interface. Full article

The scientific literature lacks sufficient data on the transport of various toxic pollutants by polymer particles. Investigating how the structure of microplastic particles formed during the degradation of polymeric materials affects pollutant sorption processes will improve our ability to predict environmental behavior. General-purpose polystyrene, expanded polystyrene, ABS plastic (acrylonitrile–butadiene–styrene) and crosslinked polystyrene are produced on an industrial scale. Copolymers of styrene with divinylbenzene are used on a large scale as sorbents for gel permeation chromatography (Styragel brand sorbents), in the production of catalysts on a polymer substrate or ion-exchange resins. In this study, non-spherical, crosslinked polystyrene microparticles with varying polystyrene chain packing densities were used as model microplastic particles representative of crosslinked polystyrene. It was shown that the adsorption of a hazardous chemical rhodamine B was influenced by both the packing density of the polystyrene chains and the presence of ionic functional groups, i.e., the “degree of aging” of the microplastic particles. The sorption capacities of these model microparticles were compared with those of natural origin (silicon dioxide, quartz powder, and microcrystalline cellulose). A viability assay using HEK293 and HeLa cell lines exposed to leachates from both pristine and rhodamine B-loaded microparticles revealed that all unmodified microparticles, regardless of their nature, exhibited no cytotoxicity at concentrations up to 1000 μg/mL. In contrast, microparticles with adsorbed rhodamine B significantly reduced cell viability to 20–40% at concentrations of 100 μg/mL. Full article

A major limitation for the wider use of membrane-based technologies is the presence of biofouling, which is related to the decline of permeate flux, as well as the associated energy and economic costs for the necessary cleaning. In this work, the interactions and compatibility of 28 common polymeric materials with 36 potential biofoulants (categorized in six groups) is examined, based on Hansen Solubility Parameters (HSPs). Also, a simple methodology is proposed for polymer screening and comparing the suitability of 28 polymers to be used as fabrication materials or coatings, aiming to produce membranes with lower biofouling potential. The methodology gives a score to each polymer based on its interaction with water and various foulants. The screening among the commonly used polymers showed that poly (vinyl alcohol) (PVOH) is a good selection for the manufacturing of membranes, or for effective surface coating to limit biofouling, when compared to the other candidate polymers. The case of PVOH material received the highest score (11.6), while other polymers ranked with lower scores (less than 10). Its physically cross-linked nature that arises from a strong self-association pattern may also be beneficial for biofouling mitigation, since it limits the available sites for interactions (e.g., through hydrogen bonds) with the potential foulant agents. Swelling experiments on the PVOH gels with real wastewater (produced after anaerobic digestion) support the predictions for lowering the biofouling potential. Full article

The swelling-regulated transport properties of modified and cross-linked HPC-based hydrogel formulations containing NaCMC and citric acid were studied as stimuli-responsive polymeric membranes under various conditions, including deionized water. Physiological conditions were simulated by evaluating various pH conditions (1.2, 6.8, and 7.4). The pseudo-second-order kinetic model best described the swelling process, suggesting that both solvent uptake capacity and polymer network relaxation contribute to the extent of swelling. The swelling behavior of the hydrogel formulations was significantly influenced by salt concentration. The modified HPC hydrogel system exhibited stimuli-responsive swelling–switching behavior under saline, water/ethanol, and acidic/basic environments, demonstrating reversible swelling–deswelling cycles. Maximum swelling was observed in water at pH 7.4. In contrast, abrupt deswelling in an ethanol solution at pH 1.2 reduced hydrogel swelling and water uptake. The effect of temperature on the swelling behavior of the hydrogel and its thermo-responsive swelling behavior was also evaluated. Drug release behavior suggested diffusion-mediated release through the swelling hydrogel matrix. These findings suggest that the modified HPC-based hydrogel system may be useful for pH-responsive oral drug delivery applications. Full article

Forward osmosis (FO) membranes have garnered widespread research interest in water treatment, yet their permeability–selectivity trade-off, internal concentration polarization, and membrane fouling remain critical challenges. Herein, a chitooligosaccharide/polydopamine (COS/PDA) co-deposition strategy was proposed to modify polyethersulfone (PES) substrates for constructing high-performance thin-film composite (TFC) FO membranes. COS suppressed excessive PDA aggregation, reduced substrate roughness, and improved substrate hydrophilicity. This substrate modification regulated interfacial polymerization by increasing the adsorption capacity for m-phenylenediamine (MPD) while slowing its diffusion rate, thereby forming thinner, smoother, and more densely crosslinked polyamide (PA) layers. The optimized C₄P₁-TFC membrane delivered water fluxes of 42.2 and 23.5 L m⁻² h⁻¹ in pressure-retarded osmosis (PRO) and FO modes, respectively, representing 43.1% and 40.2% improvements over the pristine membrane. Its specific salt flux decreased to 0.07 and 0.15 g L⁻¹ in the two modes, respectively, suggesting enhanced selectivity. Meanwhile, the C₄P₁-TFC membrane showed antibacterial rates of 85.7% against Escherichia coli and 86.9% against Staphylococcus aureus, together with improved antifouling performance against bovine serum albumin and lysozyme. This work presents a simple and effective co-deposition approach for simultaneously improving the separation, antibacterial, and antifouling performance of TFC FO membranes, showing promising potential for practical applications. Full article

This study presents the development of an eco-friendly brick for mining, a sustainable composite material manufactured from gold mine tailings and used cooking oil (UCO) through a thermal oxypolymerization process. Unlike conventional stabilization methods, which often require additional materials beyond tailings or have a high carbon footprint in their production, this approach uses oxypolymerization to transform these two waste products into novel building materials. The use of various percentages of UCO at different heating temperatures was evaluated to identify the optimal mixture, determining that a 9% UCO content and a 9 h cycle are key conditions for inducing fatty acid crosslinking. This logical relationship between heat treatment and dosage allows the organic binder to consolidate the mineral matrix, giving the material a compressive strength of 19.12 MPa and a flexural strength of 8.24 MPa, exceeding the thresholds of the NTE INEN 297 standard. The low water absorption (2.86%) is attributed to the densification of the matrix and the hydrophobic nature of the polymerized oil, indicators of its structural durability. This work is the first to use Ecuadorian tailings as the sole mineral aggregate, validating a high-efficiency, low-impact product for sustainable construction under the principles of the circular economy. Full article

Magnesium oxide (MgO) nanoparticles, recognized for their versatile applications from catalysis to biomedicine, require synthesis methods that offer precise control over their properties while ensuring safety and scalability. This study explores a safer, industrially viable adaptation of the polyacrylamide gel synthesis route by utilizing magnesium sulfate (MgSO₄) instead of conventional nitrates to mitigate explosion risks during calcination. A systematic study was conducted to evaluate the influence of key synthesis parameters, such as crosslinker ratio, initiator concentration, precursor loading, calcination conditions (including temperature, time, and heating rate), pH, and the use of chelating agents (EDTA and citric acid), on the purity, morphology, size distribution, and colloidal stability of the synthesized MgO nanoparticles. Characterization via X-ray spectroscopy XRF and XRD, acoustic spectroscopy, nitrogen physisorption (BET), electronic microscopy SEM and TEM and dispersion stability analysis revealed that polymeric cell volume (controlled by crosslinker and initiator) significantly influences size distribution, while chelating agents in alkaline environments drastically reduce particle size to ~20 nm and alter morphology to platelets (EDTA) or polygonal shapes (citric acid). Crucially, a low heating rate (2.5 °C/min) was found to yield smaller particles (~30 nm) and higher purity. This work provides a comprehensive blueprint for the tailored, safe, and scalable synthesis of MgO nanoparticles with targeted properties for specific technological applications. Full article

Injectable hydrogels have attracted substantial and rapidly growing interest due to their ability to be administered into cavities of any shape and provide local therapeutic treatment. This study reports the synthesis and characterization of thermosensitive microgels and hydrogels obtained via photoinitiated copolymerization of methacrylated gelatin (GN-MA) and N-isopropylacrylamide (NIPAM) in the absence and presence of N,N′-methylenebisacrylamide (MBA). The effects of monomer concentration, crosslinker content (MBA), and irradiation time on product yield, grafted chain length, and material properties were systematically investigated. Depending on the polymerization conditions, microgel samples exhibited hydrodynamic diameters in the range of 354–1022 nm at 20 °C, which decreased to 183–308 nm upon heating to 40 °C. Freeze-drying of the microgel dispersions resulted in the formation of a porous sponge-like structure with pore sizes of 50–90 µm. Rheological studies of the hydrogel properties demonstrated evident thermoresponsive behavior, with storage moduli (G′) ranging from 20 to 600 Pa, matching the mechanics of certain soft tissues. The hydrogels showed high equilibrium swelling capacity at 20 °C, which was reduced at 40 °C, as well as temperature-dependent moxifloxacin release (38–88% over 6 days) and excellent biocompatibility (>85% cell viability) with human skin fibroblasts. These findings make them promising for biomedical applications such as postoperative cavity filling and local drug delivery. Full article

Hydrocolloids comprise a diverse class of high-molecular-weight polymeric carbohydrates associated with a wide range of physicochemical and functional properties. This review provides an integrated analysis of natural hydrocolloids derived from algal (agar, alginate, carrageenan, fucoidan, laminarin, and ulvan), animal (chitin, chitosan, chondroitin sulfate, dermatan sulfate, keratan sulfate, heparin, heparan sulfate, glycogen, and hyaluronan), and plant (pectin, starch, and locust bean gum) sources, together with semisynthetic cellulose-based derivatives. Emphasis is placed on the relationship between molecular structure, charge density, sulfation patter, and branching degree, and how these parameters modulate hydration, gelation, and rheological behavior. Comparative analyses are presented, establishing structure–function interactions that link molecular characteristics to functional properties, including thickening, gelling, emulsifying, stabilizing, film-forming, and controlled-release capacities. The review also discusses the biological activities and application potential of these hydrocolloids in pharmaceutical, biomedical, and advanced material systems. In addition, emerging modification strategies, including chemical functionalization, crosslinking, and nanostructuring are discussed as tools to adjust their action and diversify their application range. Special attention is given to structure–rheology–gelation relationships and to the influence of molecular organization on mechanical strength, stability, and delivery performance. Current challenges associated with scalability, processability, reproducibility, and long-term functional stability are also critically discussed. Overall, this review provides a comprehensive structure–function perspective on hydrocolloids as sustainable and multifunctional polymeric materials, supporting their rational design and continued development in pharmaceutical sciences, biomedical engineering, and advanced material applications. Full article

Branched poly(vinyl alcohol) (PVA) was synthesized via chemical modification of linear PVA with epichlorohydrin in an alkaline aqueous medium under conditions preventing crosslinking. Branching was confirmed by IR and Heteronuclear Single Quantum Coherence (HSQC) spectroscopy, as well as by viscometric analysis. An iterative procedure is proposed for refining the branching factor (g) and the viscosity-average molecular weight of the branched macromolecules. Coil diameters determined by viscometry and dynamic light scattering showed satisfactory agreement. While an increase in the viscosity-average molecular weight of branched PVA enhances its surface activity in the low-adsorption region, the branched geometry itself hinders subsequent adsorption due to steric shielding of the interface. This correlates with wetting behavior on Teflon: lightly branched PVA requires a higher concentration to induce wetting inversion than its linear counterpart but further increase in molecular weight shifts the inversion point to lower concentrations due to a higher density of hydroxyl groups. Concurrently, the concentration dependence of the work of adhesion degenerates with increasing molecular weight. Despite their reduced adsorption capacity, the specific geometry of branched PVA macromolecules provides effective steric stabilization of micrometer-sized particles during styrene suspension polymerization. These results demonstrate that chain branching in PVA is a powerful tool for tuning its adsorption properties, stabilizing ability, and interfacial activity. Full article

Thin-film composite (TFC) polyamide (PA) nanofiltration membranes are the state of the art for water purification and reclamation, although a selectivity–permeability trade-off often restricts their development. To mitigate this problem, in this work, a novel three-layer structured nanofiltration (NF) membrane was fabricated consisting of a negatively charged poly (sodium 4-styrenesulfonate) (PSS) interlayer, a high-performance polyethyleneimine (PEI)-based PA separation layer and a PEI-grafted top layer. The PSS interlayer aimed to regulate interfacial polymerization (IP) of PEI with trimesoyl chloride (TMC) and enhance water transport, while PEI-grafting ensured high salt rejections. The relevant characterizations indicated that PEI-grafting endowed the resulting membrane (I-TFC-g) with a positive surface charge and increased the crosslinking degree to achieve much higher rejections for Mg⁺² ions through the synergistic effect of Donnan and size-exclusion mechanisms, while the incorporation of the PSS interlayer resulted in an increased pure-water permeability (PWP) value of 7 L m⁻² h⁻¹ bar⁻¹ (a value 2.8 times higher compared to the membrane TFC-g without a PSS interlayer). In specific, the I-TFC-g membrane displayed the highest salt rejections of 91% for MgCl₂, 92% for MgSO₄, 73% for Na₂SO₄ and 58% for NaCl and a good long-term stability. Overall, this work presents a simple strategy to improve NF performance by simultaneous enhancement of water permeability and salt selectivity. Full article