Search Results (684)

Cellulose nanofiber (CNF)–boron nitride nanotube (BNNT) composite separators have been widely investigated; however, many demonstrations rely on BNNT pretreatment or multistep processing to secure dispersion and integration. HwBKP-derived CNF separators (HCNF), based on an enzymatically pretreated and turbulence-flow nanomill processed CNF suspension, were combined with BNNTs without pretreatment to fabricate BNNT-incorporated composite membranes (HBNT-05 and HBNT-10) via a simple stirring–filtration–drying route. The CNF suspension and membranes were characterized by fibril image analysis, SEM, AFM, FTIR, and XRD, together with wettability and surface free-energy measurements, to examine BNNT-loading-dependent changes in separator structure and surface microtexture. When evaluated in NCM811||Li half-cells, the BNNT-incorporated membranes exhibited composition-dependent electrochemical performance trends relative to the BNNT-free CNF membrane, while the commercial polyolefin reference remained favorable at the highest tested C-rate. These results suggest that the present fabrication route enables effective BNNT incorporation without BNNT pretreatment under the studied conditions, providing a practical strategy to tune biomass-derived CNF membranes for energy-storage applications. Full article

Aqueous zinc-ion batteries (AZIBs) are promising for large-scale grid storage due to inherent safety, low cost, environmental compatibility, high theoretical capacity (820 mAhg⁻¹), and suitable redox potential (−0.763 V vs. SHE). However, practical deployment is hindered by coupled challenges at the zinc anode–hydrogen evolution, dendrite growth, and corrosion/passivation, which severely limit cycle life and coulombic efficiency. This review systematically summarizes key advances in AZIB research. It first elucidates working principles and four cathode energy storage mechanisms: Zn²⁺ insertion/extraction, H⁺/Zn²⁺ co-insertion, chemical conversion, and dissolution/deposition. Second, it examines four mainstream cathodes (manganese-based, vanadium-based, Prussian blue analogs, and organic compounds), analyzing performance bottlenecks and corresponding optimization via structural modification. Third, it explores functional mechanisms of advanced separators (polymer, inorganic/ceramic composite, MOF-based, and cellulose-based) in regulating uniform Zn²⁺ deposition and suppressing dendrites. Fourth, it summarizes anode optimization strategies: artificial protective layers for interface stabilization, electrolyte additives to modulate Zn²⁺ solvation/deposition, and 3D porous structures to reduce local current density and provide nucleation sites. Finally, key scientific challenges and future directions are discussed—multi-strategy synergy, in situ characterization, practical battery construction, and sustainable technological development, offering theoretical guidance for advancing AZIBs toward large-scale applications. This review aims to provide a comprehensive perspective spanning from materials to systems, and from mechanisms to applications. Its core objective is not merely to list the types of cathode materials, but to establish a logical bridge directly connecting “key challenges” to “optimization strategies,” with a particular emphasis on the issues and solutions related to the cathode side. Full article

The inherent hydrophobicity of polyolefin separators significantly impedes rapid electrolyte wetting, thereby limiting the electrochemical performance of lithium-ion batteries. Cellulose, as a hydroxyl-rich natural polymer, serves as an ideal material for enhancing the interface properties of separators. However, there is still a lack of systematic understanding regarding how the morphological structures of cellulose (such as granular, fibrous, or network-like forms) influence the coating structure and ion transport mechanisms. Here, three representative cellulose derivatives—microcrystalline cellulose (MCC), cellulose nanofibers (CNF), and bacterial cellulose (BC)—were selected to construct functionalized polypropylene (PP) composite separators through vacuum filtration. Experimental results demonstrate that all three cellulose coatings reduced contact angles from 50.8° to below 10°, significantly enhancing interfacial affinity. Systematic comparison reveals that cellulose configuration decisively influences separator performance: unlike the dense fiber entanglement networks formed by CNF and BC, the unique rigid granular packing structure of MCC maintains hydrophilicity while establishing more permeable ion transport pathways. Among these, MCC@PP exhibited optimal electrochemical performance, with the lithium-ion migration number increasing to 0.41 and a capacity retention rate of 88.04% after 100 cycles at 0.5 A/g. This study elucidates the relationship between cellulose configuration and the modification of separator performance, demonstrating that MCC represents a more efficient, robust, and cost-effective option for separator modification compared to complex fiber networks. Full article

It is essential to develop a practical technology for the separation and capture of carbon dioxide (CO₂) due to the gradually increased concentration of CO₂ in the atmosphere, which has driven the rise in global temperature. Membrane separation is regarded as a promising technology for the capture of CO₂. However, most membranes employ non-biodegradable petroleum-based polymers. In this study, biodegradable and renewable membranes of cellulose acetate (CA) doped with polyethylene glycol (PEG) and polyethylene glycol diacrylate (PEGDA) were fabricated by solution casting and used for the separation of CO₂/O₂. The results indicated that the membrane doped with PEGDA exhibited higher permeability of CO₂ and selectivity of CO₂/O₂ compared to those doped with PEG, while improving the tensile strain and structural uniformity of membranes. The membrane with a thickness of 25 μm at a PEGDA dosage of 10 wt% achieved optimal gas permeability, selectivity, and mechanical toughness, showing CO₂ permeability of 4.59 Barrer and CO₂/O₂ selectivity of 5.68. The structure of the interpenetrating polymer network was responsible for the excellent properties of the membrane doped with PEGDA due to the formation of more mid- and micro-sized pores that increase the diffusion pathways of CO₂. Full article

A synergistic and magnetically recoverable NiFe₂O₄–MWCNT–CA nanocomposite was developed for efficient UV-driven photodegradation of hazardous organic pollutants. Biogenic NiFe₂O₄ nanoparticles synthesized using Costus speciosus extract exhibited a crystallite size of 32.5 nm, which increased to 83.6 nm upon incorporation into the MWCNT–cellulose acetate matrix. XRD confirmed the preservation of the cubic spinel structure, while VSM analysis showed maintained ferrimagnetic behavior with a saturation magnetization of 9.64 emu/g, enabling rapid magnetic separation. Although BET analysis revealed a reduction in surface area from 112.46 to 30.99 m²/g due to hybridization, the conductive MWCNT network significantly enhanced charge separation and interfacial electron transport. The composite displayed a widened optical bandgap of 5.3 eV, necessitating UV excitation for photocatalytic activity. Under UV irradiation, it achieved rapid degradation of methylene blue (97%) and Congo red (91%) at 20 mg/L, with corresponding rate constants of 0.119 and 0.076 min⁻¹. Scavenger experiments confirmed hydroxyl radicals (•OH) as the dominant reactive species, followed by photogenerated holes (h⁺). These results demonstrate a robust and synergistically engineered photocatalyst with high efficiency in removing organic pollutants under UV illumination. Full article

Rapid industrialization and global population growth have led to numerous environmental issues. Among these issues, water polluted with toxic heavy metal ions (HMIs) has become a serious problem. Of the various removal methods, adsorption is considered to be one of the most widely used for purifying wastewater due to its simple operation, high adsorption efficiency, low cost and broad applicability. Bio-based hydrogels are becoming increasingly popular for water purification due to the variety of fabrication and modification methods available. These hydrogels act as adsorption aggregators, increasing the local concentration of HMIs. Bio-based fluorescent hydrogels with fluorescent sensors could be further used to sensitively detect the HMIs, accompanied by an obvious fluorescence quenching. The non-radiative energy transfer between the fluorescent sensor and the adsorbed metal ions is responsible for the sensitive detection. In this review, the recent progress of bio-based fluorescent hydrogels for the adsorption and sensing of toxic HMIs is fully summarized. According to the natural hydrogel sources, the bio-based hydrogels, including cellulose-, chitosan-, alginate- and lignin-based hydrogels, are discussed separately. Finally, the challenges, suggestions and opportunities involved in developing novel bio-based fluorescent hydrogels for the adsorption and sensing of toxic HMIs are presented. Full article

Background/Objectives: Dietary fibers play key roles in shaping gut microbiome and intestinal homeostasis. While purified diets offer experimental precision and reproducibility in rodent models, they omit the complex mixture of fermentable and non-fermentable fibers found in grain-based chow diets. We hypothesized that excluding fermentable fiber impairs intestinal homeostasis by reducing microbial metabolites and altering the colonic epithelial transcriptome, thereby increasing susceptibility to inflammation. Methods: Wildtype male C57BL/6 mice were maintained on either a standard grain-based chow diet or a purified low-fat diet (LFD) containing 5% non-fermentable cellulose for ten weeks. Fecal microbiomes, short-chain fatty acid (SCFA) profiles, and colonic epithelial transcriptomes were analyzed. A separate group was challenged with dextran sodium sulfate (DSS) following a five-week dietary intervention to compare colitis severity between the two diet groups. Results: Relative to mice fed the grain-based chow, those consuming the purified LFD (containing only non-fermentable cellulose) showed decreased gut microbial diversity and significantly lower SCFA levels. These changes were accompanied by marked differences in colonic epithelial cell transcriptomes. In LFD-fed mice, the top upregulated gene networks included ribosomal pathways and MHC complex protein binding, suggesting increased growth and gut inflammation. The most downregulated pathways included mineral absorption, actin and tubulin binding, and membrane organelle assembly, indicating major alterations in cellular structure and transport. LFD-fed mice also exhibited increased colonic expression of S100a9, a gut inflammation biomarker, and more severe disease symptoms when challenged with DSS compared to chow-fed mice. Conclusions: Fermentable fibers are one of the factors contributing to intestinal homeostasis and mitigating the severity of ulcerative colitis. Full article

Background/Objectives: Although copper nanoparticles (Cu-NPs) are increasingly explored as food and feed additives, there is still limited evidence on how the commonly consumed dietary fibre matrix modulates their effects on the gut microbiota. This study evaluated whether different dietary fibres (cellulose, pectin, inulin, psyllium) modulate Cu-NP–driven changes in caecal microbiota activity, composition, and bile acid metabolism in rats in a multifactorial design accounting for fibre type, copper dose, and copper form. Methods: Wistar male rats (n = 10 per group, 10 groups) were fed semi-purified diets for 6 weeks. Cu-NPs were provided at 6.5 or 13 mg Cu/kg diet and combined with cellulose (control fibre) or with pectin, inulin, or psyllium. Caecal digesta parameters, microbial enzyme activities, short-chain fatty acids (SCFAs), bile acids, and 16S rRNA sequencing were used to assess microbial diversity. Results: Final body weight did not differ among groups, whereas feed intake decreased most consistently with inulin and psyllium. Inulin and psyllium increased caecal digesta and tissue mass, while pectin increased caecal ammonia. Higher Cu-NPs dose reduced several microbial enzyme activities and lowered major SCFAs across most treatments; pectin most strongly preserved/enhanced glycosidase activities and was associated with increased SCFA levels vs. control, with a 32% rise in acetate, a 47% rise in propionate, and a 61% rise in butyrate. Fibre type dominated bile acid outcomes: psyllium reduced total bile acids by 11.8% vs. control, while inulin increased muricholic acids by 216% vs. control. Microbiota alpha and beta diversity separated primarily by fibre type, with distinct clustering particularly in pectin-fed groups. Across comparisons, Mucispirillum was consistently reduced in fibre-supplemented groups vs. cellulose, alongside recurrent changes in selected genera; functional profiling highlighted shared shifts in carbohydrate, fermentation, transport, and stress-response features under Cu-NPs exposure. Conclusions: The gastrointestinal and microbiota responses to Cu-NPs are strongly fibre-dependent; thus, Cu-NP safety and functionality should be evaluated together with the accompanying dietary fibre matrix, not as a standalone exposure. Implications for humans remain indirect and require confirmation in human-relevant models and clinical settings. Full article

Due to its affordability, widespread availability, non-toxicity, biodegradability, and renewability, cellulose is considered a crucial material for addressing the depletion of petroleum resources. In this study, a rotaxane-based supramolecular polymer derived from thermoplastic polyurethane (TPU) was synthesized and combined with cellulose to create a TPU–cellulose composite (TPU-C). This composite was employed as a separator for acrylate-based quasi-solid polymer electrolytes (QPEs). The polymer electrolyte demonstrated a high ionic conductivity of 0.16 mS cm⁻¹ at room temperature, a lithium-ion transference number of 0.63, and an electrochemical stability window extending up to 4.7 V. When paired with a LiFePO₄ (LFP) cathode, the coin cell retained 88.8% of its capacity after 100 cycles at 1 C. A cell assembled with Li and a high-voltage NCM622 cathode maintained a capacity of 65.8% after 100 cycles at 0.3 C. Additionally, the excellent electrochemical performance was analyzed through density functional theory (DFT) calculations to identify the underlying reasons for its outstanding behavior. This study offers new insights into expanding the application potential of cellulose-based composite materials. Full article

This study presents a sustainable strategy for developing high-performance supercapacitor separators through the upcycling of waste newspapers into functional cellulose-based membranes. The intrinsic porous architecture of cellulose fibers was exploited as a robust scaffold, onto which Parylene C and polyaniline (PANI) layers were sequentially introduced to reinforce mechanical integrity and enhance electrochemical functionality. The resulting dual-layer configuration exhibited significantly improved interfacial stability and ion-transport characteristics compared with conventional polyethylene separators. Comprehensive structural and electrochemical analyses verified that the synergistic combination of Parylene C and PANI coatings effectively optimized separator–electrolyte interfacial properties and reduced impedance. Beyond performance enhancement, this work establishes an environmentally responsible route for valorizing paper waste, offering a viable pathway toward sustainable energy storage technologies. Full article

Membrane bioreactors (MBRs) exhibit highly variable removal efficiencies for pharmaceutical metabolites and organic micropollutants, even under similar operating conditions. Diclofenac and carbamazepine, for instance, show elimination rates that differ markedly across installations and studies. The membrane’s separation parameters—pore size, diameter, or structure—and the chemical nature of its material do not fully explain these differences. Instead, processes at the sludge–membrane interface, particularly sorption and biofilm-related interactions, appear to dominate. Recent studies indicate that MBR performance depends largely on events at the membrane surface: microbial adhesion mechanisms, biofilm development, and community organization. Better pollutant removal stems from prolonged contact with the biofilm and transformation within this layer, not from mechanical filtration alone. Here, we examine membrane surface modification strategies using biopolymers (cellulose, chitosan, and alginate) and their effects on membrane–biofilm interactions. Research suggests that effective biopolymer coatings for MBRs must stabilize the hydration layer, maintain near-neutral surface charge, show moderate cross-linking density for durability and flexibility, and create controlled nanotopography that favors porous, active biofilms over compact sludge layers. This understanding supports the development of durable, low-energy MBR membranes with improved stability and more predictable micropollutant removal in real-world applications. Full article

This study presents a novel multifunctional Lac@CMC-Cu@Fe₃O₄ nanocomposite for the efficient immobilization of laccase designed to overcome limitations in enzyme stability, reusability, and catalytic performance. The nanocomposite integrates magnetite (Fe₃O₄) for rapid magnetic separation, carboxymethyl cellulose (CMC) as a biocompatible matrix for covalent enzyme attachment, and copper nanoparticles to enhance catalytic activity. The immobilization achieved an impressive yield of 87%, with comprehensive characterization by XRD, FT-IR, FESEM, EDX, BET, and VSM confirming successful synthesis and enzyme attachment. Kinetic analysis revealed a remarkable 37% increase in maximum reaction velocity (Vmax = 111 µmol/min) compared to free laccase (81.3 µmol/min), despite a moderate increase in Km from 1.54 to 3.22 mM. The immobilized biocatalyst demonstrated superior thermal stability, retaining 53% activity at 60 °C versus 17% for the free enzyme, and exhibited a broader pH tolerance, maintaining 41% activity at pH 8.0. Notably, the biocatalyst showed enhanced performance in organic solvents, with 153% activation in acetone. Operational reusability was exceptional, retaining 84% activity after 15 cycles, and storage stability was significantly improved, maintaining 68% activity after 90 days compared to only 11% for free laccase. This magnetically separable nanobiocatalyst represents a promising, scalable platform for sustainable industrial and environmental applications. Full article

Efficiently separating propene and propane is paramount for the chemical industry but notoriously difficult due to their minimal size and volatility differences. Here, an efficient strategy to overcome this separation challenge was demonstrated through the design of bimetallic zeolitic imidazolate framework (ZIF)-based mixed-matrix membranes (MMMs). Thin-film composite (TFC) membranes were fabricated by integrating monometallic ZIF-8, ZIF-67, and a synergistic bimetallic ZIF-8-67 into a uniquely formulated ionic liquid–cellulose acetate (IL–CA) polymer matrix. Structural and morphological analyses confirmed the high crystallinity of the ZIF fillers and their seamless integration within the polymer. The resultant ZIF-8-67/IL-CA membrane exhibited notable separation performance, surpassing its monometallic counterparts by a threefold increase in both C₃H₆ permeance and C₃H₆/C₃H₈ ideal selectivity relative to the base membrane. Under industrially relevant mixed-gas testing, the membrane achieved a competitive separation factor of eight for propene over propane. These findings reveal that the strategic integration of bimetallic nodes in ZIFs can unlock synergistic properties unattainable with single-metal frameworks. This work presents a robust and scalable platform for developing next-generation membranes that defy conventional performance trade-offs, paving the way for efficient membrane-based olefin/paraffin separations. Full article

Residual lignocellulosic biomass represents a major resource to be incorporated into the circular economy, with up to 1400 Mt/y in EU27. Due to its complex composition of three biopolymers (cellulose, hemicellulose and lignin) combined with its seasonal and regional variability and high water content, its valorization involves manifold challenging aspects. Herein a three-step procedure is presented to transform this type of biomass into solid composite panels: hydrothermal carbonization (HTC), dry thermal treatment and curing a phenolic resin. HTC triggers chemical dehydration of the polysaccharide part of the lignocellulose and breaks up the cell structure of the plants. This facilitates the diffusion of the water and its separation by filtration, which is more energy efficient than evaporation. HTC and thermal treatment induce chemical changes that concentrate the carbon content and make the material suitable for crosslinking with a phenolic resin, achieving a 90% renewable content. The composite panels are competitive with products of the particle and fiberboard sector with respect to tensile strength and screw withdrawal resistance. Hence, the products can be employed for construction or in the furniture industry. Full article

Agricultural leftovers from oilseed crops represent an underutilized lignocellulosic resource for integrated biorefinery. In this work, rapeseed straw (RS) and sunflower stalk (SS) were evaluated as raw materials for the simultaneous recovery of hemicelluloses, lignin, and cellulose-rich fibers. Direct soda pulping (20% NaOH, 160 °C, 45 min) or a combination of soda pulping with water pretreatment or alkaline extraction (water or 2% NaOH, 110 °C, 40 min) were the methods used in the process. Acid precipitation was used to remove lignin from the process fluids, whereas ethanol was used to separate hemicelluloses. FTIR spectroscopy, HPLC of acidic hydrolysates, and chemical composition analysis were used to analyze solid fractions and recovered biopolymers. The combination alkaline extraction–soda pulping produced the greatest material removal: 55% for RS and 70% for SS. Xylan was the main component of the isolated hemicellulose fraction: 44.86% for RS and 40.09% for SS. Paper sheets produced from the resulting pulps exhibited tensile strength indices of 35–55 N·m/g and burst indices of 1.1–2.4 kPa·m²/g, meeting requirements for hygiene and fluting packaging papers. These results prove that RS and SS are suitable feedstocks for integrated, multi-stream biorefinery, enabling the concurrent production of paper-making fibers and value-added biopolymers. Full article