Cellulose最新文献

This study examined the possibility of improving the disintegration, and thermal and mechanical properties of polyurethane used by the footwear industry, specifically for safety footwear, requiring high-quality standards, by the addition of nanocellulose. The double objective was the reusability of waste considered non-reusable and its valorization towards higher-performance products with lower environmental impact, i.e., transforming an “environmental problem” into a key element of upgrading. Nanocellulose was obtained by a mechanical approach assisted by ball milling, from valuable cellulose coming from the treatment of post-consumer and post-industrial Personal Absorbent Products (PAP), possessing the strong advantage of being separated from lignin and hemicellulose, which avoids the expensive steps of separation. The precious secondary raw materials (SRMs) obtained, possessing strong hydrophilicity due to the presence of abundant hydroxy groups, were easily dispersed in hydrophilic PU, and were characterized and studied. In particular, a three-phase experimental approach was implemented, from the laboratory evaluation of the first formulations, up to the production of new soles for safety shoes, containing nanocellulose from waste, in a manufacturing line. The activities were supported by an extensive characterization performed in close cooperation with company laboratories, aimed at evaluating the real applicability of new products. The results of the mechanical tests highlighted the ability of nanocellulose to induce significant improvements in the mechanical performance of the nanocomposites, both in terms of elastic modulus and resistance, e.g., from 5.1 to 40.51 MPa for polyurethane containing nanocellulose. In particular, the presence of nanocellulose led to an increase in resistance to tearing, aging, and abrasion. An increase in disintegration was observed in the evaluation of Soil Burial Tests. A higher tendency towards degradation for nanocellulose-loaded materials was verified. A model was proposed for the evaluation of degradation over time up to 100% degradation, which showed excellent fitting with the experimental data (R-sq) of 99.77%.

Chitosan is a biodegradable polymer and is often used as a substitute for conventional petroleum-based packaging. However, it requires the incorporation of other components to achieve active properties with enhanced mechanical properties. In this study, chitosan (CS) is incorporated with thiolated chitosan (TCS) forming a semi-interpenetrating polymer network. Tagetes minuta essential oil (TMEO) is further embedded in this polymeric network to harness its antioxidant potential. The composite films of CS/TCS are prepared with different amounts of TMEO using the solvent casting method. These films are characterized via FTIR and FE-SEM, confirming the integration of TMEO into the films. The developed film (CS/TCS/TMEO-1) exhibits ≈93% enhancement in water vapor barrier properties and ≈84% increment in tensile strength as compared to CS/TCS film. The film also shows good antioxidant properties (≈88%), thus presenting its enormous potential as an active packaging material to reduce lipid oxidation and prolong the shelf-life of processed readymade food items.

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The development of efficient and stable photocatalysts for nitrogen photofixation is necessary and remains challenging. Herein, sulfur doped carbon nitride was composited with cerium oxide (SCN/CeO), which was treated by oxygen vacancies (OVs) engineering to remain Ce³⁺/Ce⁴⁺ redox pairs for the improvement of photocatalytic activity. Further, SCN/CeO was loaded at wheat straw cellulose hydrogel (WSCH) to form SCN/CeO@WSCH composited photocatalysts for the enhancement of dispersity and stability. The optimized SCN/CeO-3 catalyst, treated with hydrazine hydrate, exhibited an optimal Ce³⁺/Ce⁴⁺ ratio and abundant OVs, synergistically boosting visible-light-driven conversion of nitrogen-to-ammonia. Without sacrificial agents, SCN/CeO-3 achieved a nitrogen fixation efficiency of 39.19 μmol g⁻¹ h⁻¹ within 120 min. WSCH was used as catalyst support to improve catalyst dispersion and active site accessibility, which elevated the efficiency to 75.34 μmol g⁻¹ h⁻¹ under identical conditions, and maintained an excellent stability after five cycles. In this study, S-doping effectively expanded the visible light response range. Oxygen vacancies in cerium oxide facilitated N₂ adsorption/activation, while the Ce³⁺/Ce⁴⁺ pair enhanced charge separation and electron transfer. In addition, wheat straw cellulose hydrogel (WSCH) derived from agricultural waste straw not only stabilized the catalyst, but also contributed to environmental sustainability. Therefore, the designed research system integrated redox-active metal centers, vacancy engineering, element doping and eco-friendly supports, which provides new insights into designing novel photocatalytic systems for renewable energy applications.

The development of hyperbranched cellulose for wastewater remediation is of great interest due to their eco-friendly and cost-effective advantages. Considering this, the present work reports the tailoring of microcrystalline cellulose (MCC) with hyperbranched polyethyleneimine (HPEI) and investigates its potential as an adsorbent for wastewater remediation. A graft copolymerization reaction of MCC was carried out with the glycidyl methacrylate monomer, yielding a maximum graft yield of 89.28% after 120 min at a temperature of 45 °C. HPEI-tailored-MCC was then synthesized by the reaction of grafted MCC and HPEI at 60 °C. MCC-grafted and HPEI-tailored samples were validated using FT-IR, 13C NMR, SEM, XRD, TGA, and BET techniques. BET analysis of MCC and the adsorbent confirmed its mesoporous structure, as there was a decrease in the surface area of the adsorbent. The surface area of MCC was 247.64 m²/g, whereas that of HPEI-tailored-MCC was 78.90 m²/g. The point zero charge (P_ZC) of the adsorbent was determined to be 7.7, and the maximum dye removal occurred at acidic pH. HPEI-tailored-MCC was used as an adsorbent for the quick and effective removal of tartrazine (TA) and amaranth (AMR) acidic organic dye pollutants from wastewater. Different adsorption factors, namely, adsorbent dosage, initial dye concentration, contact time, pH, and adsorbent regeneration, were studied during the adsorption process. It was found that 80% of both dye pollutants were removed within 5 min of adsorption, and equilibrium was achieved within 15 min. Adsorption data were evaluated by non-linear fittings for both kinetics and isotherm studies. The adsorption isotherm profile followed the Redlich-Peterson isotherm model for amaranth dye and the Tempkin model for tartrazine dye. At a 200 mg/L dye concentration, HPEI-tailored-MCC adsorbent exhibited a maximum adsorption capacity of 155.71 mg/g for TA and 92.45 mg/g for AMR, respectively.

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A multifunctional cotton fabric was fabricated by in-situ synthesis of zeolitic imidazolate framework-8 (ZIF-8) on a polydopamine (PDA)-modified cotton substrate. Leveraging the reducing capability of PDA, silver nanoparticles (Ag NPs) were simultaneously incorporated into and around the ZIF-8 nanocrystals. The successful fabrication of the Ag/ZIF-8 functional cotton fabric was confirmed by characterization techniques including SEM, XRD, XPS, and TG. The modified fabric exhibits exceptional photocatalytic performance and cycling stability, achieving 93.4% degradation of methylene blue (MB) under visible light irradiation within 170 min and retaining 90.2% efficiency after three degradation cycles. Furthermore, the synergistic effect between Ag and ZIF-8 endows the fabric with significant antibacterial activity and efficient heavy metal ion adsorption capacity. Therefore, this study provides a novel strategy for designing multifunctional materials, holding significant promise for advancing the development of multifunctional textiles.

To address the safety and performance challenges of lithium-ion batteries, particularly the risk of thermal runaway and inefficient ion transport, we developed a hydroxyethyl cellulose (HEC)/nonwoven fabric (NWF) composite membrane with high mechanical strength and a vertically aligned porous structure. The membrane integrates the mechanical robustness of biodegradable HEC with the thermal and chemical stability of the NWF substrate. Vertically aligned pores were formed via ethanol-induced phase separation under vacuum, facilitating rapid ion transport. Mercury porosimetry analysis confirmed an increased porosity (69.6%) with a well-defined pore size distribution. The membrane demonstrated a high ethanol flux (2659 ± 88 L/m²·h), low Gurley value (26.0 ± 13.3 s/100 mL), an ultra-hydrophilic contact angle of 19.8 ± 6.2°, and enhanced ion exchange capacity (1.3 × 10⁻³ meq/g), demonstrating excellent permeation and wettability properties. Intermolecular interactions between HEC and NWF were supported by FT-IR. Thermogravimetric analysis further showed improved thermal stability after phase separation. These results suggest that the fabricated membrane holds promise as a highly porous and thermally stable separator exhibiting superior permeation and wettability, thereby enhancing the safety and ionic conductivity of lithium-ion batteries.

Reversible thermochromic textiles are one of the remarkable advancements in Smart Textiles. In this study, a new approach was explored to produce reversibly thermochromic cotton fabrics suitable for smart textile applications by studying commercial leuco-based thermochromic dyestuff through conventional pad-dry-cure method. Effects of varying dyestuff concentrations, crosslinking agents, and migration inhibitors were systematically investigated to optimise thermochromic responsiveness and durability. Scanning electron microscope (SEM) analyses confirmed the dyestuff presence on the cotton fibres. Incorporation of binder significantly improved the dyestuff’s adherence to the cotton fibres. Fourier-Transform Infrared Spectroscopy (FTIR) validated the presence of thermochromic dyestuff on cotton fibres. The dyed cotton fabrics exhibited phase transition temperatures (approximately 30 °C) very similar to that of thermochromic dyestuff. Regarding thermochromic performance, all dyed samples demonstrated high responses, exhibiting clear colour changes when heated from 20 °C to 40 °C. The colour changes were preserved even after 100 heating–cooling cycles and after multiple washing cycles, confirming enhanced durability. Results demonstrated that pad-dry-cure method can successfully impart reversible thermochromic functionality to cotton fabrics. The new method is both feasible and effective in achieving reversible colour changes with satisfactory fastness properties. This approach offers a promising alternative to microencapsulation techniques and contributes to the advancement of sustainable, cost-effective, and functional Smart Textiles by utilizing conventional dyeing infrastructures for fabrication of thermochromic cotton fabrics.

Oil spills and waste oil discharges generate vast quantities of oily wastewater, posing severe ecological and environmental challenges that also endanger human health, necessitating the development of advanced and efficient oil–water separation membranes. In this work, a novel sodium alginate fiber (SA) based superhydrophilic/underwater superoleophobic (SUS) membrane was developed for oil-in-water (o/w) separation through a facile method by blending SA nanofibers with UiO-66-NH₂/MgAl-LDH cluster-assembled microspheres. The micron-scale spheres were embedded within SA nanofibers, resulting in the formation of a loosely stacked nanofiber structure that enhanced water permeability. The obtained composite membrane exhibited good o/w separation performance with a high separation efficiency of > 99% and a flux rate of ~ 2661 L m⁻² h⁻¹. Moreover, the underwater oil contact angle (OCA) of U-LDHn@SA composite membrane was around 140°, which indicated that U-LDHn@SA composite membrane has good underwater superoleophobicity. After 10 cycles, the oil–water separation efficiency exceeded 99%, and the water flux always exceeded 2021 L m⁻² h⁻¹. The composite membrane also exhibited the potential to separate oil-in-water emulsion with the highest oil rejection of 94%. The membrane showed antifouling properties, recyclability, and stability in harsh conditions. This work provides a new idea for the development of oil–water separation membranes with practical applications.

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It is a great challenge to achieve high degradation activity and excellent stability of efficient immobilizing muti-component catalyst systems. Herein, a homogeneous pre-solution involving hydrolyzed tetrabutyl titanate and cellulose alkaline/urea solution were proposed to achieve highly dispersed TiO₂ in cellulose microspheres via in-situ mineralization. The partially exposed TiO₂ nanoparticles could act as the anchor points for further mineralizing goethite (FeOOH) with the assistance of tannic acid. As a result, the well-designed TiO₂/FeOOH binary catalyst system immobilized on the porous cellulose aerogels exhibited broadened light response range and enhanced charge transfer efficiency. The removal ratio of tetracycline (TC) for TiO₂/FeOOH immobilized microspheres (TFMS) was over 87.8% in 40 min via photo-Fenton degradation. More importantly, TFMS maintained the degradation efficiency over 83.0% after 5 rounds degradation, while the removal ratio of TC on microsphere immobilized only with FeOOH was reduced to 24.3%. This design of anchor structure on an immobilized catalyst system provides a new strategy to balance the stability and active site exposure of multi-component catalyst systems for efficient and safe water treatment.

Bast fibers—a type of natural cellulose fiber characterized by distinct cavity shapes and surface chemical properties with hierarchical pore structures—like ramie, hemp, and linen—show notable benefits in gas adsorption. Compared to synthetic deodorizing materials, these bio-based fibers offer better biodegradability, renewability, and environmental compatibility. However, systematic research on the odor adsorption effectiveness of different bast fibers is still limited, especially when it comes to the structure–activity relationship between adsorption mechanisms and microstructural features. In this study, we investigate the adsorption behavior and underlying mechanisms of four cellulose fibers—degummed ramie, hemp, linen, and scoured cotton—using ammonia and acetic acid as model odor molecules. A range of multiscale characterization methods, including adsorption kinetic models, scanning electron microscopy (SEM), inverse gas chromatography (IGC), and density functional theory (DFT) were employed in our analysis. Our results reveal that ramie fiber, with its longitudinal grooves and loosely fibrillated structure, exhibits the highest adsorption capacity for ammonia (0.278 mg·g⁻¹) and acetic acid (2.81 mg·g⁻¹), attributable to its larger specific surface area (8.96 m2·g⁻¹) and greater number of active sites Further investigation uncovers a synergistic process involving both chemical and physical adsorption. This study not only offers novel perspectives for development of high-performing, environmentally friendly deodorizing materials but also provides a theoretical basis for utilizing bast fibers in odor-control functional textiles.