Cellulose最新文献

The recycling of waste textiles is of great significance for reducing carbon emissions and promoting sustainable development. It is an important measure to effectively supplement the supply of raw materials in the textile industry, alleviate resource and environmental constraints, and is also an essential part of establishing a sound green economic system. This work focuses on the literature review of chemical separation technology of polyester/cotton blended textiles, highlighting the component separation of polyester and cotton fibers through polyester depolymerization and cellulose dissolution. For the polyester depolymerization separation route, we have examined the advantages and disadvantages of hydrolysis, alcoholysis, and ethylene glycol alcoholysis in depolymerizing polyester to achieve component separation of blended textiles. For the hydrolysis or dissolution separation of the cotton component, we have elaborated on the hydrolysis of cellulose under acidic conditions and the dissolution process of cellulose in non-derivatizing solvents. Meanwhile, we also conducted a survey on the application progress of enzymatic hydrolysis technology in the field of component separation of blended textiles, aiming to gain a more comprehensive understanding of the current technological status and development direction of waste polyester/cotton blended textile component separation. Finally, we summarized the existing problems and challenges of the chemical separation technology for blended textiles, including fabric decolorization, and looked forward to the future trends in the chemical recycling of waste textiles. We expect that this review will provide a reference for the green regeneration and application development of waste polyester/cotton blended textiles.

Petroleum-derived single-use plastics have dominated a range of material applications, including packaging and service ware (e.g., water bottles, food containers, and drinking straws). However, despite their short-lived service life, the inherent durability, and stability of these plastics have resulted in significant environmental accumulation and spill, contaminating both aquatic and land ecosystems. Consequently, there is a surging interest in the development of bioplastics as a sustainable alternative to petrochemical derived plastics that align with circular economy principles. Among potential materials, cellulose acetate (CA) showcases impressive mechanical properties, optical characteristics, melt processability, and compostability. However, due to its hygroscopic behavior, inferior barrier properties, and lack of dimensional stability, CA applications in the packaging industry are minimal. In this research, the acetylation of lignin and its use as a functional filler for CA matrix was studied. The impact of varying lignin loadings (up to 30 wt.%) on the tensile, morphological, barrier, and viscoelastic properties of the resulting materials was investigated. A thorough characterization of the compression-molded acetylated lignin-CA films revealed a reduction in water uptake (by 59% over baseline), up to a 41.5% reduction in water vapor permeability, and enhanced tensile properties with melt flowability. In summary, the examined films displayed favorable characteristics for use in food and other packaging applications. Consequently, they serve as low carbon footprint, and eco-friendly substitutes for conventional petrochemical-based packaging materials.

The use of biocide-loaded hydrogels has recently been exploited for cleaning the biological attacks of cultural heritage and architectural stone materials. However, considering the drawbacks of traditional biocides, and the high costs of synthetic polymers, growing research for innovative and sustainable solutions are taking place. The aim of this work is to explore a bacterial cellulose (BC) hydrogel functionalized with ozone as a renewable, biodegradable, and easy-to-use antimicrobial remedy for stone biodeterioration. The BC microstructure was characterized by Field Emission-Scanning Electron Microscopy observation and high crystallinity was detected by X-ray diffraction analysis. Ozonated BC (OBC) hydrogels were tested against selected biodeteriogenic microorganisms in water suspension abolishing their viability, with its complete suppression after a 10-min and a 24-h treatment with OBC, for bacterial and fungal spores, respectively. Furthermore, the OBC was assessed on contaminated marble, brick, and biocalcarenitic stone specimens for simulating in situ conditions. A 100% reduction of microbial viability after a 24-h treatment was obtained. Successively, the shelf-life of the hydrogel and the antimicrobial activity were also evaluated after 30 days, demonstrating a subsequent cleaning efficiency along time. This research highlights the potential of the new ozonated BC hydrogel as a green and highly effective antimicrobial treatment, with advantages in sustainability.

A new strategy for multifunctional coatings with flame retardancy, superhydrophobicity and UV shielding ability on cotton fabrics (SFR cotton) was realized by step-by-step spraying ammonium phytate, lignin and hybrid nanoparticles of polydimethylsiloxane (PDMS) modified mesoporous silica nanoparticles (MSNs) with entrapped Fe₂O₃ (PDMS@Fe₂O₃-MSNs). The surface adhesion PDMS@Fe₂O₃-MSNs constructed micro/nano-scale surface structure on SFR cotton fabric, which endowed superhydrophobic (WCA = 152 ± 1.3°), anti-fouling and self-cleaning properties. Benefiting from the synergistic effects of the physical barrier provided by the PDMS@Fe₂O₃-MSNs and the intumescent flame-retardant properties of ammonium phytate and lignin, the SFR cotton fabric demonstrated excellent self-extinguishing performance under an open fire and left a char layer with 8.4 cm. In addition, due to the excellent UV-absorption ability of lignin and Fe₂O₃ nanoparticles, the SFR cotton fabric was able to shield the UV irradiation damages to rat skin. Furthermore, the SFR cotton fabric demonstrated remarkable durability against rigorous conditions, including ultrasonic washing, sandpaper abrasion, UV irradiation and exposure to strong acid/alkali environments. After 150 min of ultrasonic washing and 50 cycles of abrasion, the SFR cotton fabric could preserve its hydrophobicity, flame retardancy and UV shielding ability. In addition, the SFR cotton fabric delivered exceptional chemical stability and UV durability when exposed to strong acid/alkali for 24 h and UV irradiation (200 W) for 12 h, respectively. Significantly, the SFR cotton fabric could retain the original flexibility and breathability of pristine cotton fabric. Therefore, the simple and feasible strategy of multifunctional coatings has broad application prospects in advanced multifunctional textiles, military facilities and other fields.

Flexible lithium-ion batteries (LIBs) are receiving widespread attention, and how to obtain the high flexibility, safety, and energy density of LIBs at the same time are one of the main challenges in the field of flexible electronics. The multi-network structure formed by cellulose nanofiber (TOCNF) not only provided sufficient mechanical support and excellent flexibility for the electrode but also promoted uniform distribution of conductive agents and active materials. In this work, we prepared an eco-friendly TOCNF binder from wheat straw, using a method involving 2, 2, 6, 6-tetramethylpiperidinyl-1-oxyl oxidation and high-intensity ultrasonic treatment. Additionally, we enhanced the performance of TOCNF by introducing Li⁺ through ion exchange, resulting in lithium-functionalized cellulose nanofibers (TOCNF-Li), which were employed as a novel binder for LiFePO₄ cathodes. The findings show that, when employing TOCNF-Li binder, batteries were able to obtain an initial discharge capacity of 163 mAh g^–1 at 0.1 C rate and maintained 93.2% of the initial reversible capacity after 400 cycles at 2 C rate. Notably, at 5 C rate, the discharge capacity reached 133.7 mAh g⁻¹, with a capacity decay of only 16.1%. TOCNF-Li played a role in increasing Li⁺ content, opening a new pathway for Li⁺ transport, consequently enhancing Li⁺ diffusion efficiency and charge–discharge performance. Overall, TOCNF-Li serves as a novel, environmentally friendly, and efficient binder for flexible LIBs.

The proliferation of microorganisms in outdoor stone sculptures and cultural objects can damage the structure and aesthetics of the materials through biodeterioration mechanisms. Biocides and synthetic products are often used to prevent this phenomenon, despite their negative impact on the environment and human health. Less toxic alternatives with reduced environmental impact can be an option for the preventive conservation of stone sculptures to reduce the environmental impact. In this work, chitosan formulations reinforced with two types of cellulose crystals (microcrystalline cellulose (MCC) or cellulose nanocrystals (CNCs)) and with or without citric acid and sodium tripolyphosphate were prepared. The films obtained with these formulations showed low solubility, and those only containing MCC or CNCs had the lowest wettability. The formulation containing 2% (w/v) MCC was selected for further analysis and supplemented with oregano essential oil (OEO) at 1% (v/v) and 2% (v/v), exhibiting low solubility, swelling and wettability when polymerised in film form. Inoculation of the films with Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa and Rhodotorula spp. resulted in total or partial inhibition of their growth, as well as a 60–100% reduction in Penicillium chrysogenum growth, depending on the concentration of OEO. The formulation with 2% (v/v) OEO was applied to samples of granite, marble and limestone, forming a protective, yet irregular coating on their surfaces. The wettability of the stones’ surfaces was reduced without becoming completely water-repellent and the coating did not cause visible colour changes.

Cellulose nitrate, commonly known as nitrocellulose (NC), is an energetic polymer with a broad function in industrial and military applications. The use of biomass waste for nitrocellulose production offers a promising solution to the growing demand for renewable and sustainable raw materials, addressing one of the most critical issues of recent decades. However, the product quality remains suboptimal, presenting one of the biggest challenges in developing NC production from biomass. Enhancing NC performance through the modification of cellulose crystal structures and allomorph is considered an excellent approach. Herein, the transformation of cellulose-I into cellulose-II was explored during the hydrolysis step to produce high-performance NC. The present study demonstrated that cellulose-II precursors effectively produced the highest-performance NC from the solid byproducts of avocado seed extraction (EAS), highlighting its promising potential for high-energy applications.

Evidence supports that hyaluronic acid (HA) can promote tissue regeneration and reduce inflammation. This study aimed to assess the effects of a bilayered cellulose-coated HA scaffold on oral wound healing. A film-type 3% HA scaffold with bilayer cellulose coating was prepared and compared with an HA scaffold without coating. To evaluate cytocompatibility, human gingival fibroblasts were exposed to both scaffolds, and cell viability, flow cytometry, and scratch wound assays were performed. In addition, in vivo and ex vivo wound-healing assays were performed. Cytocompatibility tests showed no cytotoxicity for either HA scaffold. The scratch wound assay revealed a significant reduction in the open wound area in both HA scaffolds compared with that in the control (p < 0.05); however, no differences were observed between the scaffolds with and without cellulose coating. In vivo wound healing analysis showed significantly higher healing rates on day 3 in the HA scaffolds than in the control (p < 0.05), with no significant differences between the scaffolds. HA scaffolds with coating showed lower CD68 and higher vimentin expression than the control (p < 0.05), whereas HA scaffolds without coating did not. Ex vivo wound healing analysis revealed significantly higher re-epithelialization rates in both scaffolds than in the control (p < 0.05). Within the limits of this study, the HA scaffold with coating showed enhanced wound healing efficacy, indicating its potential for oral wound healing applications.

Untreated cotton usually needs to be scoured to remove hydrophobic pectin and wax for the demands of subsequent processing such as dyeing and finishing. Pectinase can degrade pectin on cotton fibers, but the catalytic efficiency is not particularly high. This study developed a new scouring method for cotton fabrics by pectin hydrolase combined with an ascorbic acid (VC)/H₂O₂ Fenton-like system. The GPC results showed that water-soluble pectin (1969.2 kDa) could be degraded into 10.6 kDa within 30 min through pectinase with VC/H₂O₂. The FTIR results suggested that VC/H₂O₂ breaks the ester bonds on water-soluble pectin. The results of XPS demonstrated that the α-1,4-glycosidic bonds of pectin could be degraded more effectively through VC/H₂O₂ oxidation and pectinase hydrolysis. The fabrics scoured with VC/H₂O₂–pectinase exhibited a reduction in wetting time (from > 200 to 8.04 s) and an increase in vertical wicking height (from 0.1 to 6.70 cm) in comparison to the fabrics treated with pectinase. The pilot-scale machine experiments yielded satisfactory performance with VC/H₂O₂–pectinase scoured fabrics, suggesting that VC/H₂O₂–pectinase scouring has potential for practical application. The cotton fabric scouring by VC/H₂O₂–pectinase is a simple and efficient method with the advantages of mild treatment conditions, less damage to cotton fabrics and environmental friendliness.