Search Results (161)

The demand for anion exchange membranes (AEMs) is growing due to their applications in water electrolysis, CO₂ reduction conversion and fuel cells, as well as water treatment, driven by the increasing energy demand and the need for a sustainable future. However, current AEMs still face challenges, such as insufficient permeability and stability in strongly acidic or alkaline media, which limit their durability and the sustainability of membrane fabrication. In this study, polyvinyl alcohol (PVA) and chitosan (CS) biopolymers are selected for membrane preparation. Zinc oxide (ZnO) and porous organic polymer (POP) nanoparticles are also introduced within the PVA-CS polymer blends to make mixed-matrix membranes (MMMs) with increased OH⁻ transport sites. The membranes are characterized based on typical properties for AEM applications, such as thickness, water uptake, KOH uptake, Cl⁻ and OH⁻ permeability and ion exchange capacity (IEC). The OH⁻ transport of the PVA-CS blend is increased by at least 94.2% compared with commercial membranes. The incorporation of non-porous ZnO and porous POP nanoparticles into the polymer blend does not compromise the OH⁻ transport properties. On the contrary, ZnO nanoparticles enhance the membrane’s water retention capacity, provide basic surface sites that facilitate hydroxide ion conduction and reinforce the mechanical and thermal stability. In parallel, POPs introduce a highly porous architecture that increases the internal surface area and promotes the formation of continuous hydrated pathways, essential to efficient OH⁻ mobility. Furthermore, the presence of POPs also contributes to reinforcing the mechanical integrity of the membrane. Thus, PVA-CS bio-based membranes are a promising alternative to conventional ion exchange membranes for various applications. Full article

This study synthesized two eco-friendly inhibitors—a chitosan–copper metal–organic framework (CS@Cu MOF) and chitosan–Schiff base–Cu complex (Schiff–CS@Cu)—for Q345 steel protection in 3.5% NaCl/1M HCl. Electrochemical and weight loss analyses demonstrated exceptional corrosion inhibition: untreated specimens showed a 25.889 g/(m²·h) corrosion rate, while 100 mg/L of CS@Cu MOF and Schiff–CS@Cu reduced rates to 2.50 g/(m²·h) (90.34% efficiency) and 1.67 g/(m²·h) (93.56%), respectively. Schiff–CS@Cu’s superiority stemmed from its pyridine–Cu²⁺ chelation forming a dense coordination barrier that impeded Cl⁻/H⁺ penetration, whereas CS@Cu MOF relied on physical adsorption and micro-galvanic interactions. Surface characterization revealed that Schiff–CS@Cu suppressed pitting nucleation through chemical coordination, contrasting with CS@Cu MOF’s porous film delaying uniform corrosion. Both inhibitors achieved optimal performance at 100 mg/L concentration. This work establishes a molecular design strategy for green inhibitors, combining metal–organic coordination chemistry with biopolymer modification, offering practical solutions for marine infrastructure and acid-processing equipment protection. Full article

The aim of this study was to evaluate the effect of suture material made of polyester (PET), polypropylene (PP), and polytetrafluoroethylene (PTFE) on the calcification of a bovine pericardium (BP) consisting of collagen biopolymer preserved with an epoxy compound. Non-porous film made of the synthetic reinforced polymer REPEREN^® was chosen as a control material. Samples of the material (sutured or non-sutured with each of the three types of surgical sutures) were implanted subcutaneously in 45 young rats for 30, 60, and 90 days. The calcium content of the explants was quantified using atomic absorption spectrometry, a histological examination was performed using hematoxylin and eosin and von Kossa staining, and the structure of the calcium phosphate deposits was studied using scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) with color field mapping. The results demonstrated the absence of calcification in the non-sutured BP and in all the REPEREN^® groups. In the sutured BP samples, a dynamic increase in the Ca content and the Ca/P ratio to 1.67–1.7 (crystalline hydroxyapatite) was observed by the 90th day. The minimum Ca content among the sutured BP groups was detected in samples where the PET thread was used. The cellular reaction to BP was significantly more pronounced than the reaction to REPEREN^® throughout the entire observation period; collagen homogenization was noted near the sutures. It can be concluded that all the studied suture materials provoke BP calcification. PET has the minimal negative effect. Full article

Hierarchical porous carbon materials hold great potential for energy storage applications due to their high porosity, large specific surface area, and excellent electrical conductivity. Cellulose and sodium alginate are naturally abundant high-molecular-weight biopolymer materials. Utilizing them as precursors for the fabrication of high-performance electrochemical carbon materials is highly significant for achieving carbon neutrality goals. In this study, porous carbon aerogels were successfully synthesized using a combination of freeze-drying and a simple carbonization process, with nanocellulose and sodium alginate as precursors. Among the prepared samples, SC-0.03 (sodium alginate: nanocellulose = 0.1:0.03) exhibited the best performance, achieving a specific surface area of 713.7 m² g⁻¹. This material features an optimized hierarchical pore structure and a substantial intrinsic oxygen doping content, resulting in excellent capacitance performance. Benefiting from these structural advantages and their synergistic effects, the SC-0.03 electrode demonstrated a high specific capacitance of 251.5 F g⁻¹ at a current density of 0.5 A g⁻¹. This study shows that the construction of three-dimensional porous structures by taking advantage of the self-supporting properties of natural polymer materials does not require the introduction of external binders. Due to the nanoscale dimensions and high aspect ratio, nanocellulose enables the formation of a more refined and interconnected hierarchical pore network, enhancing ion accessibility and conductivity. The hierarchical porous carbon aerogel developed in this study, based on a biomass self-reinforcement strategy, not only shows great promise as an advanced energy storage material but also possesses environmentally friendly properties, offering new insights for the development of sustainable energy materials. Full article

This study reports on the design and development of novel porous biomaterials based on chitosan, water kefiran, and paramylon, enriched with various concentrations of juniper berry oil (JBO). The materials were obtained by freeze-drying and comprehensively characterized. The analyses included morphological evaluation (SEM and porosity), physicochemical tests (swelling rate, water vapor transmission rate, and roughness), mechanical tests (tensile strength, Young’s modulus, and elongation at break), and biodegradability under physiological conditions. Moreover, the functional behavior of the materials was evaluated by assessing their antioxidant and anti-inflammatory activity, as well as interactions with selected proteins (human serum albumin and fibrinogen) relevant to biological responses. It was found that the presence of JBO affects the internal structure and improves selected properties in a concentration-dependent manner. This study is the first to investigate the combined use of chitosan, water kefiran, and paramylon in a single porous system enriched with JBO. The results confirm the importance of such biopolymer sponges as promising platforms for applications where appropriate physicochemical and bioactive properties are desired. Full article

This study explores the etymological roots of nature and nature-inspired design within the context of soil stabilisation. It outlines Aristotle’s doctrine of hylomorphism and applies these concepts to develop a pathway for the stabilisation of clays within their original porous or looser structure through interparticle modifications. A biopolymer is introduced to a base clay thorough a procedure that imitates forms, matter, generative processes, and functions of arbuscular mycorrhizal (AM) fungi. For the first time, the void ratio was progressively increased from 0.50 to 0.70, and the air ratio from 0.15 to 0.33, reflecting a systematic transition from a denser to a looser packing state. A 20% increase in shear wave velocity indicated enhanced interparticle engagement following treatment. This reinforcement effect contributed to the preservation of stiffness and residual strength, despite a 120% increase in air ratio and a 63% reduction in degree of saturation, alongside a modest improvement in unconfined compressive strength. The findings presented here mark a departure from both conventional and emerging stabilisation techniques, enabling engineered soil to remain porous, to loosen with time, and to continue delivering engineering and ecological services. Full article

The environmental impact of conventional plastics has spurred interest in biopolymers as sustainable alternatives, yet their performance under abiotic degradation conditions still remain unclear. This study investigated the effects of ultraviolet C (UV-C) irradiation and its combination with water immersion (UV-C/H₂O) on films of commercial poly(butylene adipate-co-terephthalate)-thermoplastic starch (PBAT/TPS) blends. Changes in structural, chemical, morphological, and thermal properties, as well as molar mass, were analyzed. The results showed distinct degradation mechanisms during exposure to UV-C irradiation either in dry or during water-immersion conditions. UV-C irradiation disrupted PBAT ester linkages, inducing photodegradation and chain scission, leading to a more pronounced molar mass decrease compared to that under water immersion, where a more restrained impact on the molar mass was ascribed to diffuse attenuation coefficient of irradiation. Nevertheless, under UV-C/H₂O conditions, erosion and disintegration were enhanced by dissolving and leaching of mainly the TPS fraction, creating a porous structure that facilitated the degradation of the film. Blends with higher TPS content exhibited greater susceptibility, with pronounced reductions in PBAT molar mass. In conclusion, exposure of films of PBAT/TPS blends to ultraviolet/water-assisted environments effectively initiated abiotic degradation, in which fragmentation was accentuated by the contribution of water immersion. Full article

The present study investigates the potential of novel mixed matrix membranes that are formed from the biopolymer carboxymethyl cellulose (CMC) and the metal–organic framework ZIF-8 to improve the pervaporation dehydration of isopropanol. The effect of ZIF-8 content variation and porous substrate selection (comprising cellulose acetate (CA) and polyacrylonitrile) on dense and supported membrane properties is systematically investigated using multiple analytical techniques. It is found that ZIF-8 incorporation alters the membrane structure (confirmed by FTIR and NMR), increases surface roughness (observed via SEM and AFM), enhances swelling degree (obtained by swelling measurements), improves surface hydrophobicity (determined by contact angle analysis), and elevates thermal stability (verified by TGA). Quantum chemical calculations are used to validate the interactions between the polymer matrix, modifier, and feed components. The transport properties of developed membranes are evaluated through the dehydration of isopropanol via pervaporation. The cross-linked supported CMC membrane with 10 wt% ZIF-8 prepared on the CA substrate has the optimal performance: permeation flux of 0.136–1.968 kg/(m²h) and ˃92 wt% water in the permeate via the dehydration of isopropanol (water content 12–100 wt%) at 22 °C. Full article

Industrial textile wastewater containing both heavy metals and dyes has been massively produced. In this study, semi-interpenetrating polymer network structures of sodium alginate (SA)/polyvinyl alcohol (PVA)/κ-carrageenan (CG) aerogel beads were synthesized for their simultaneous reduction. The SA/PVA/CG aerogel beads were synthesized through a cost-effective and environmentally friendly method using naturally abundant biopolymers without toxic cross-linkers. The SA/PVA/CG aerogel beads were spheres with a size of 3.8 $\pm$ 0.1 mm, exhibiting total pore areas of 15.2 m²/g and porous structures (pore size distribution: 0.04–242.7 μm; porosity: 93.97%) with abundant hydrogen bonding, high water absorption capacity, and chemical resistance. The adsorption capacity and mechanisms of the SA/PVA/CG aerogel beads were investigated through kinetic and isotherm experiments for heavy metals (Cu(II), Pb(II)), cationic dye (methylene blue, MB), and anionic dye (acid blue 25, AB)) in both single and binary systems. The maximum adsorption capacities of the SA/PVA/CG aerogel beads based on the Langmuir model of Cu(II), Pb(II), and MB were 85.17, 265.98, and 1324.30 mg/g, respectively. Pb(II) showed higher adsorption affinity than Cu(II) based on ionic properties, such as electronegativity and hydration radius. The adsorption of Cu(II), Pb(II), and MB on the SA/PVA/CG aerogel beads was spontaneous, with heavy metals and MB exhibiting endothermic and exothermic natures, respectively. Full article

Complex coacervation using proteins and polysaccharides enables efficient microencapsulation with high thermal stability, facilitating continuous core component release and yielding coacervates with superior properties for diverse applications. This study investigates the use of casein and pectin for microencapsulating Ocimum basilicum L. essential oil (EO) and phenolic extract (PE). Microencapsulation yield and efficiency were 85.3% and 89.8% for EO microcapsules (EO-MC) and 53.1% and 70.0% for PE microcapsules (PE-MC). Optical microscopy revealed spherical microcapsules; EO-MC had smooth surfaces, while PE-MC had porous surfaces. Thermal analysis showed stability, with both types exhibiting two stages of weight loss. XRD analysis indicated increased crystallinity in EO-MC and high crystallinity in PE-MC due to phenolic interactions. FTIR spectroscopy confirmed molecular interactions, including hydrogen bonding between phenolic compounds and the biopolymer matrix and amide bonds between the carboxyl groups of pectin and the amino groups of casein, ensuring the successful encapsulation of the bioactive compounds. These findings highlight the potential of casein and pectin for microencapsulating extracts, particularly EOs, for food industry applications. Full article

Drug delivery systems have revolutionized traditional drug administration methods by addressing various challenges, such as enhancing drug solubility, prolonging effectiveness, minimizing adverse effects, and preserving potency. Nanotechnology-based drug delivery systems, particularly nanoparticles (NPs) and nanofibers (NFs), have emerged as promising solutions for biomedicine delivery. NFs, with their ability to mimic the porous and fibrous structures of biological tissues, have garnered significant interest in drug-delivering applications. Biopolymers such as gelatin (Ge) and chitosan (CH) have gained much more attention due to their biocompatibility, biodegradability, and versatility in biomedical applications. CH exhibits exceptional biocompatibility, anti-bacterial activity, and wound healing capabilities, whereas Ge provides good biocompatibility and cell adhesion properties. Ge/CH-based NFs stimulate cellular connections and facilitate tissue regeneration owing to their structural resemblance to the extracellular matrix. This review explores the additive methods of preparation, including electrospinning, force pinning, and template synthesis, focusing on electrospinning and the factors influencing the fiber structure. The properties of Ge and CH, their role in drug release, formulation strategies, and characterization techniques for electrospun fibers are discussed. Furthermore, this review addresses applications in delivering active moieties in the management of orthopedics and wound healing with regulatory considerations, along with challenges related to them. Thus, the review aims to provide a comprehensive overview of the potential of Ge/CH-based NFs for drug delivery and biomedical applications. Full article

The increasing presence of pollutants, including pharmaceuticals and pesticides, in water resources necessitates the development of effective remediation technologies. Zeolites are promising agents for pollutant removal due to their high surface area, ion-exchange capacity, natural abundance, and diverse tailorable porous structures. This review focuses on the efficient application of modified zeolites and mesoporous materials as photocatalysts and adsorbents for removing contaminants from water bodies. The adsorption and photodegradation of pesticides and selected non-steroidal anti-inflammatory drugs and antibiotics on various zeolites reveal optimal adsorption and degradation conditions for each pollutant. In most reported studies, higher SiO₂/Al₂O₃ ratio zeolites exhibited improved adsorption, and thus photodegradation activities, due to increased hydrophobicity and lower negative charge. For example, SBA-15 demonstrated high efficiency in removing diclofenac, ibuprofen, and ketoprofen from water in acidic conditions. Metal doped into the zeolite framework was found to be a very active catalyst for the photodegradation of organic pollutants, including pesticides, pharmaceuticals, and industrial wastes. It is shown that the photocatalytic activity depends on the zeolite-type, metal dopant, metal content, zeolite pore structure, and the energy of the irradiation source. Faujasite-type Y zeolites combined with ozone achieved up to 95% micropollutant degradation. Bentonite modified with cellulosic biopolymers effectively removed pesticides such as atrazine and chlorpyrifos, while titanium and/or silver-doped zeolites showed strong catalytic activity in degrading carbamates, highlighting their environmental application potential. Full article

During wastewater reclamation, organic matter is considered the dominant foulant that shortens the lifetime of ultrafiltration (UF) membranes during operation. Additionally, the mineralization efficiency of organic matter in secondary effluent is typically low due to nonbiodegradable carbon sources. Herein, a combination of ozone and a porous biocarrier reactor was applied as a novel pretreatment system to enhance organic matter removal in the effluent in a lab-scale evaluation and pilot test. The results indicated that 70% of the biopolymer was removed, and the chemical oxygen demand (COD) removal efficiency was 1.8 times higher in this combined process than in the process with a porous biocarrier alone. The UF flux increased by 16% after the combined ozonation and porous biocarrier pretreatment process compared with the process with no pretreatment. Interestingly, the genus Flavobacterium (15.59%), containing biopolymer-degrading bacteria, was observed only in the combined ozone plus porous biocarrier process. Moreover, the results show that biopolymers can be removed through the combined ozone and porous biocarrier process due to partial ozone degradation, confirming that this combined process is one of the better pretreatment procedures for organic matter removal and improves the flux of UF during the wastewater reclamation process. Full article

We present a novel method for preparing bioactive and biomineralized calcium phosphate (mCP)-loaded biopolymer composite scaffolds with a porous structure. Two types of polymers were investigated as matrices: one natural, cellulose acetate (CA), and one synthetic, polycaprolactone (PCL). Biomineralized calcium phosphate particles were synthesized via wet chemical precipitation, followed by the addition of organic biominerals, such as magnesium gluconate and zinc gluconate, to enhance the bioactivity of the pure CP phase. We compared the morphological and chemical characteristics of the two types of composites and assessed the effect of biomineralization on the particle structure of pure CP. The precipitated CP primarily consisted of nanocrystalline apatite, and the addition of organic trace elements significantly influenced the morphology by reducing particle size. FE-SEM elemental mapping confirmed the successful incorporation of mCP particles into both CA and PCL polymer matrices. Short-term immersion tests revealed that the decomposition rate of both composites is slow, with moderate and gradual ionic dissolution observed via ICP-OES measurements. The weight loss of the PCL-based composite during immersion was minimal, decreasing by only 0.5%, while the CA-based composite initially exhibited a slight weight increase before gradually decreasing over time. Full article