Search Results (564)

A novel fracture fluid based on a grafting polymer, PAM-co-PAMS-g-PEG (PAM-AMS-AEG), cross-linked by an organic Zr reagent was successfully produced via free-radical polymerization and an in situ cross-linking reaction with a high conversion rate of 96%, resulting in a low molecular weight of 250 kg·mol⁻¹. The effect of fluid constitution on the rheological behavior demonstrates that the P(AM₁₀-AMS₂-AEG_1.4)/[Zr]_0.35/TBAC_0.1 (PASG/[Zr]) aqueous solution has the best comprehensive performance. The PASG/[Zr] solution with a low critical associating concentration (CAC) of 0.15 wt% showed faster and steadier disassociation–reassociation processes. The synergy of ionic hydrogen bonds between sulfonic and amine groups and Zr⁴⁺-coordination results in steady interactions and fast reconstitution of association, leading to remarkable temperature resistance from 30 to 120 °C and a fast response during thixotropic processes. The PASG/[Zr] solution reduces the damage under high pressure based on the rheological characteristics and compatibility with sand, leading to a low filtration loss of the artificial cores. The PASG/[Zr] solution exhibits a good sand-carrying ability based on the rheological and interfacial performance, resulting in slow settlement and fast suspension. The filtration performance of the PASG/[Zr] fracturing fluid showed that it is not sensitive to the shearing rate, core permeability, or pressure. The comprehensive performance of the PASG/[Zr] fracture fluid is better than that of traditional guar fluid, suggesting that it can be used under various conditions for stratum protection and shale gas extraction. Full article

Hydrogels have garnered significant attention as multifunctional materials in next-generation rechargeable batteries due to their high ionic conductivity, mechanical flexibility, and structural tunability. This review presents a comprehensive overview of hydrogel types—including natural, synthetic, composite, carbon-based, conductive polymer, and MOF hydrogels—and their synthesis methods, such as chemical crosslinking, self-assembly, and irradiation-based techniques. Characterization tools like SEM, XRD, and FTIR are discussed to evaluate their microstructure and performance. In rechargeable batteries systems, hydrogels enhance ionic transport and mechanical stability, particularly in lithium-ion, sodium-ion, zinc-ion, magnesium-ion, and aluminum-ion batteries. Despite their advantages, hydrogels face challenges such as limited mechanical strength, reduced stability under extreme conditions, and scalability issues. Current research focuses on advanced formulations, self-healing mechanisms, and sustainable materials to overcome these limitations. This review highlights the pivotal role of hydrogels in shaping the future of flexible, high-performance, and environmentally friendly secondary batteries. Full article

Gellan gum (GG) is a promising biomaterial due to its biocompatibility, tunable gelation, and modifiability. This study investigates the influence of triple crosslinking mechanisms—thermal gelation, UV-induced covalent crosslinking, and ionic crosslinking—on the mechanical and physicochemical properties of GG-based hydrogels, designed to function as a neuromaterial with hierarchical neuro-architecture as a potential nerve substitute for peripheral nerve injury. Initial thermal gelation forms a physical network via double-helix junctions. Methacrylation introduces vinyl groups enabling UV crosslinking, while post-treatment with Mg²⁺ ions strengthens the network through ionic bridging with carboxylate groups. Plasticizers—glycerol and triethyl citrate—were incorporated to modulate chain mobility, network hydration, swelling behavior, and mechanical flexibility. Seven-day erosion studies showed that glycerol-containing hydrogels eroded 50–60% faster than those with triethyl citrate and up to 70% more than hydrogels without plasticizers, indicating increased hydrophilicity and matrix loosening. In contrast, triethyl citrate reduced erosion, likely due to tighter polymer chain interactions and reduced network porosity. Mechanical testing of 1% v/v methacrylated GG hydrogels revealed that 1.5% v/v triethyl citrate combined with UV curing (30–45 min) produced tensile strengths of 8.76–10.84 MPa. These findings underscore the synergistic effect of sequential crosslinking and plasticizer choice in tuning hydrogel mechanical properties for neuro application. The resulting hydrogels offer potential as a neuromaterial in peripheral nerve injury where gradient mechanical properties with hydration-responsive behavior are required. Full article

This study aims to address the poor extensibility, brittleness, and limited hydration stability of pure sodium alginate (SA) hydrogels, which hinder their use in flexible, skin-adherent applications such as facial masks, by developing bio-based composites incorporating five representative functional additives: xanthan gum, guar gum, hydroxyethyl cellulose (HEC), poly(ethylene glycol)-240/hexamethylene diisocyanate copolymer bis-decyl tetradeceth-20 ether (GT-700), and Laponite^® XLG. Composite hydrogels were prepared by blending 1.5 wt% SA with 0.3 wt% of each additive in aqueous humectant solution, followed by ionic crosslinking using 3% (w/w) CaCl₂ solution. Physicochemical characterization included rotational viscometry, uniaxial tensile testing, ATR-FTIR spectroscopy, swelling ratio analysis, and pH measurement. Among them, the SA/XLG composite exhibited the most favorable performance, showing the highest viscosity, shear-thickening behavior, and markedly enhanced extensibility with an elongation at break of 14.8% (compared to 2.5% for neat SA). It also demonstrated a mean swelling ratio of 0.24 g/g and complete dissolution in water within one year. ATR-FTIR confirmed distinct non-covalent interactions between SA and XLG without covalent modification. The hydrogel also demonstrated excellent conformability to complex 3D surfaces, consistent hydration retention under centrifugal stress (+23.6% mass gain), and complete biodegradability in aqueous environments. Although its moderately alkaline pH (8.96) may require buffering for dermatological compatibility, its mechanical resilience and environmental responsiveness support its application as a sustainable, single-use skin-contact material. Notably, the SA/XLG composite hydrogel demonstrated compatibility with personalized fabrication strategies integrating 3D scanning and additive manufacturing, wherein facial topography is digitized and transformed into anatomically matched molds—highlighting its potential for customized cosmetic and biomedical applications. Full article

The development of advanced wound dressing materials with enhanced antibacterial properties is critical for improving patient outcomes and reducing infection risks. This study introduces a novel bio-based aerogel composed of copper-crosslinked alginate and hyaluronic acid, synthesized using supercritical gel drying techniques. Alginate and hyaluronic acid polymers are widely used in the pharmaceutical and medical industries because of their nontoxicity, biodegradability, and biocompatibility. This study aimed to create an aerogel that could be used as a potential wound dressing material by crosslinking hyaluronic acid and alginate with copper. The bio-based aerogel was prepared by ionic gelation and supercritical gel drying. The prepared materials were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), BET surface area analysis, and energy-dispersive X-ray fluorescence (XRF). Moreover, the aerogel wound dressing properties were evaluated in terms of fluid uptake and antibacterial activity against S. aureus and E. coli. The physicochemical characterization of the prepared aerogels revealed their unique structural and morphological features, which are influenced by copper ion concentration and crosslinking time. Regarding their wound dressing evaluation, both aerogel and hydrogel were found to have antibacterial properties when tested on S. aureus with inhibition zones of (36 mm, 23 mm) and E. coli (31.6 mm, 21 mm) for hydrogel and aerogel, respectively. Also, excellent fluid uptake was found to reach up to 743%. These findings underscore the potential of copper-crosslinked alginate–hyaluronic acid aerogels as innovative wound dressing materials that combine superior antibacterial efficacy with excellent fluid management, paving the way for improved wound healing solutions. Full article

This study demonstrates that rearing duration (14 and 30 days) and environmental salinity (0, 4, 8, and 12 parts per thousand (ppt) of NaCl) synergistically modulate osmoregulation and muscle texture in adult freshwater drums (Aplodinotus grunniens). Salinity significantly reduced the hepatosomatic index at 30 days (p < 0.05). Furthermore, serum biochemical indices were markedly affected. Higher salinity and prolonged rearing time decreased triglycerides, total cholesterol, and low-density lipoprotein (LDL), while high-density lipoprotein (HDL) levels increased at 14 days (p < 0.05), indicating improved lipid metabolism efficiency. Crucially, osmotic pressure remained stable across salinities at 14 days but exhibited a dose-dependent increase at 30 days (p < 0.05), driven primarily by elevated Na⁺ and Cl⁻ concentrations. Salinity (8–12 ppt) markedly enhanced water-holding capacity, reducing cooking loss (~58%), centrifugal loss (~74%), drip loss (~83%), and thaw loss (~84%) versus 0 ppt controls (p < 0.05). Concurrently, key texture parameters also significantly improved, as reflected by hardness, chewiness, resilience, and gumminess. These enhancements might be attributed to hyperosmotic stress-induced cellular dehydration and ionic strength-mediated protein cross-linking. Full article

Conductive hydrogels are attractive for flexible electronics; however, achieving high mechanical strength and conductivity simultaneously remains challenging. Herein, we present a facile strategy to fabricate a tough and conductive hydrogel by immersing a physically crosslinked gelatin/glucose hydrogel in an aqueous sodium citrate. The introduction of sodium citrate induced multiple physical interactions via the Hofmeister effect, which synergistically reinforced the hydrogel network. The resulting hydrogel exhibited excellent mechanical properties, with a fracture strength of 2.7 MPa, a fracture strain of 932%, and a toughness of 9.5 MJ/m³. Moreover, the incorporation of free ions imparted excellent ionic conductivity of 0.97 S/m. A resistive strain sensor based on this hydrogel showed a linear and sensitive response over a wide strain range and stable performance under repeated loading–unloading cycles. These features enabled accurate and reliable monitoring of various human movements. This work offers an effective strategy for designing hydrogels with both high strength and conductivity for flexible and wearable electronics. Full article

The integration of emulsion gels in 3D food printing has emerged as a promising strategy to enhance both the structural fidelity and functional performance of printed foods. Emulsion gels, composed of proteins, polysaccharides, lipids, and their complexes, can provide tunable rheological and mechanical properties suitable for extrusion and shape retention. This review explores the formulation strategies, including phase behavior (O/W, W/O, and double emulsions); stabilization methods; and post-printing treatments, such as enzymatic, ionic, and thermal crosslinking. Advanced techniques, including ultrasound and high-pressure homogenization, are highlighted for improving gel network formation and retention of active compounds. Functional applications are addressed, with a focus on meat analogs, bioactive delivery systems, and personalized nutrition. Furthermore, the role of the oil content, interfacial engineering, and protein–polysaccharide interactions in improving print precision and post-processing performance is emphasized. Despite notable advances, challenges remain in scalability, regulatory compliance, and optimization of print parameters. The integration of artificial intelligence can also provide promising advances for smart design, predictive modeling, and automation of the 3D food printing workflow. Full article

Flexible polyurethane foams (PUFs) are widely used materials whose crosslinked chemical structure hinders conventional recycling, leading to significant environmental challenges. This study presents a selective and scalable depolymerization strategy for polyurethane foam waste (PUFW), utilizing a combination of 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]) as water-miscible ionic liquid (IL) and a strong organic base to enable hydrolytic cleavage of urethane bonds under mild reaction conditions (98 °C, atmospheric pressure). The approach was evaluated across different PUFW formulations and successfully scaled up to a 1 kg reaction mass, maintaining high efficiency in both the depolymerization and separation steps. The recovered polyols exhibited high purity and structural fidelity, comparable to those of virgin polyols. The recycled products were integrated into a new foam formulation, resulting in a PUF with mechanical and morphological properties, as revelated by scanning electron microscopy (SEM), which closely resemble those of virgin polyol-based references and surpass those of foams produced using commercially recycled polyols. These findings support the feasibility of closed-loop polyurethane recycling and represent the transition towards circular polymer economy strategies. Full article

To develop highly nutritious Bangia fusco-purpurea (BFP) vegan sausages, we investigated the effects of BFP, gluten, and xanthan gum–konjac gum–carrageenan complex gel (CG) on the gel strength and sensory quality of the sausages. The formulation process was optimized through single-factor and orthogonal tests, whereas the gel formation mechanism of the key factors was explored. The orthogonal test results showed that the optimal addition levels of BFP, gluten, and CG were 5%, 56%, and 37%, respectively. Variance analysis revealed that both gluten and CG significantly affected gel strength (p < 0.05), with gluten notably influencing the overall sensory quality (p < 0.05). Texture profile analysis (TPA) and rheological properties demonstrated that as gluten (33–37%) and CG (52–56%) concentrations increased, the gel strength and elastic modulus exhibited concentration-dependent enhancement. Further analysis of the sulfhydryl content, disulfide bonds, surface hydrophobicity, and microstructure revealed that higher gluten content promoted intermolecular disulfide crosslinking and hydrophobic group exposure, whereas CG contributed to physical filling via hydrogen and ionic bonds, resulting in a uniform and dense gel network structure. The synergistic effects of gluten and CG enhanced the gel properties of BFP vegan sausages, providing a theoretical foundation for the development of high-quality plant protein-based meat alternatives. Full article

Poly(ionic liquids) (PILs) show great promise as a new class of solid electrolytes for energy applications, including high-temperature polymer electrolyte fuel cells, owing to their combination of the unique electrochemical properties of ionic liquids and macromolecular architecture. In this study, we prepared and characterized PIL-based composite polymer electrolyte membranes containing silica nanofibers (SiO₂NFs). The SiO₂NFs were prepared via electrospinning, followed by calcination, and were used as a thermally and mechanically stable, porous substrate. The crosslinked protic PIL was synthesized via in situ radical polymerization of imidazolium hydrogensulfate-based reagents (one monomer and one crosslinker). It was then used as the membrane matrix. The prepared freestanding PIL membranes remained thermally stable at temperatures of up to 180 °C. Furthermore, the PIL/SiO₂NF composite electrolyte membranes demonstrated improved mechanical properties due to reinforcement by the NF framework. These composite membranes also exhibited relatively high proton conductivity (approximately 0.1 to 1 mS/cm) in the 100–150 °C temperature range. Full article

Polymer inclusion membranes (PIMs) have undergone substantial advancements in their selectivity and efficiency, driven by their increasing deployment in separation processes, environmental remediation, and sensing applications. This review presents recent progress in the development of PIMs, focusing on strategies to enhance ion and molecule selectivity through the incorporation of novel carriers, including ionic liquids and task-specific extractants, as well as through polymer functionalization techniques. Improvements in mechanical and chemical stability, achieved via the utilization of high-performance polymers such as polyvinylidene fluoride (PVDF) and polyether ether ketone (PEEK), as well as cross-linking approaches, are critically analyzed. The expanded application of PIMs in the removal of heavy metals, organic micropollutants, and gas separation, particularly for carbon dioxide capture, is discussed with an emphasis on efficiency and operational robustness. The integration of PIMs with electrochemical and optical transduction platforms for sensor development is also reviewed, highlighting enhancements in sensitivity, selectivity, and response time. Furthermore, emerging trends towards the fabrication of sustainable PIMs using biodegradable polymers and green solvents are evaluated. Advances in scalable manufacturing techniques, including phase inversion and electrospinning, are addressed, outlining pathways for the industrial translation of PIM technologies. The review concludes by identifying current limitations and proposing future research directions necessary to fully exploit the potential of PIMs in industrial and environmental sectors. Full article

Background/Objectives: Despite the continuous development of medicine, the treatment of dermatological fungal infections is difficult due to their chronic nature, recurrence, and resistance of some pathogens to standard therapies. In order to improve the effectiveness of treatment, not only are new active substances with antifungal activity synthesized, but new, unconventional carriers are also developed for substances already used. Methods: Therefore, the focus of this research was to evaluate the possibility of using a combination of two cross-linking techniques for sodium alginate ionic cross-linking with Zn²⁺ ions and electrostatic interaction with ε-poly-L-lysine. The pharmaceutical properties, antifungal activity against Candida strains, and compatibility with human fibroblasts of the designed hydrogels were assessed. Results: It was shown that the double cross-linking process increased the viscosity of the developed hydrogels, improved bioadhesive properties to hairless mice skin, and provided an extended release profile of the active substance. In addition, obtained formulations were characterized by improved antifungal effect against C. albicans, C. krusei, and C. parapsilosis. Prepared hydrogels expressed biocompatibility with human fibroblasts. Conclusions: Dual-cross-linked alginate hydrogels are a promising dermatological formulation that might improve the efficacy of posaconazole in the treatment of antifungal infections. Full article

Introduction. Larvae of the insect Hermetia illucens can represent an alternative source for low-molecular-weight chitosan (CS) production compared with CS from crustaceans (CS_crustac), making it appealing in terms of pharmaceutical applications. Hence, the performances of CS_larvae and CS_crustac were compared herein by investigating the in vitro features of nanoparticles (NPs) made from each polysaccharide and administered with the antioxidant quercetin (QUE). Methods. X-ray diffraction and FT-IR spectroscopy enabled the identification of each type of CS. Following the ionic gelation technique and using sulfobutylether-β-cyclodextrin as a cross-linking agent, NPs were easily obtained. Results. Physicochemical data, release studies in PBS, and the evaluation of antioxidant effects via the 1,1-diphenyl-2-picrylhydrazyl (DPPH) test were studied for both CS_larvae and CS_crustac. QUE-loaded NP sizes ranged from 180 to 547 nm, and zeta potential values were between +7.5 and +39.3 mV. In vitro QUE release in PBS was faster from QUE-CS_larvae NPs than from CS_crustac, and high antioxidant activity—according to the DPPH test—was observed for all tested NP formulations. Discussion. The agar diffusion assay, referring to Escherichia coli and Micrococcus flavus, as well as the microdilution assay, showed the best performance as antimicrobial formulations in the case of QUE-CS_larvae NPs. QUE-CS_larvae NPs can represent a promising vehicle for QUE, releasing it in a sustained manner, and, relevantly, the synergism noticed between QUE and CS_larvae resulted in a final antimicrobial product. Conclusions. New perspectives for low-molecular-weight CS are disclosed by adopting renewable sources from insects instead of the commercial CS_crustac. Full article

Prolonged drought and soil degradation severely affect soil fertility and limit crop productivity. Superabsorbent hydrogels offer an effective solution for improving water retention in soil and supporting plant growth. In this work, we examined the performance of superabsorbent hydrogels based on sodium alginate, acrylic acid (AA), and poly (ethylene oxide) (PEO) cross-linked with 12.5 kGy using e-beam irradiation. The hydrogels were assessed in various aqueous environments by examining network characteristics, swelling capacity, and swelling kinetics to evaluate the impact of water’s electrical conductivity (which ranges from 0.05 to 321 μS/cm). Morphological and chemical structure changes were evaluated using SEM and FTIR techniques. The results demonstrated that water conductivity significantly affected the physicochemical properties of the hydrogels. Swelling behavior showed notable sensitivity to electrical conductivity variations, with swelling degrees reaching 28,400% at 5 μS/cm and 14,000% at 321 μS/cm, following first-order and second-order kinetics. FTIR analysis confirmed that structural modifications correlated with water conductivity, particularly affecting the O–H, C–H, and COOH groups sensitive to the ionic environment. SEM characterization revealed a porous morphology with an interconnected microporous network that facilitates efficient water diffusion. These hydrogels show exceptional swelling capacity and are promising candidates for sustainable agriculture applications. Full article