Cellulose最新文献

As is well known, pore structure has a significant impact on the storage and transport behavior of electrolyte ions. Cellulose nanofibers (CNFs), a green biomass material, not only have good processability and flexibility, but can also be used to design and construct membrane materials with rich pore structures. It has broad application prospects in the field of flexible energy storage and has received widespread attention from researchers. However, there is still limited research on the precise design and regulation of pore structures in CNF-based composites with different pore structures, as well as their impact mechanisms on electrolyte ion storage and transport behavior. In this study, five different hierarchical structures were set up based on CNF-loaded reduced graphene oxide (CNF@RGO) composite films that were fabricated by using different lengths of CNFs as the substrate by sequential alternating filtration method. Furthermore, COMSOL Multiphysics was used for simulation and prediction to study the influence of different pore structures on their capacitance. Finally, further verification will be conducted through experiments. The simulation and experimental results show that when the internal pore structure is distributed in the order of large, small, and large pore sizes from the outside to the inside, the CNF@RGO composite material can obtain a larger area specific capacitance of 29.7 Mf cm⁻² and a higher energy density of 14.8 mWh cm⁻². As a whole, this research provides a reference direction for designing and constructing electrode materials with different pore structure combinations in the future to improve the energy storage performance of energy storage devices or electrode materials.

Satellite droplets, excessive ink spreading and penetration present significant obstacles to the advancement of inkjet printing on cotton fabrics. Traditional ink preparation methods utilizing organic solvents are unable to effectively address these issues. This study addressed these challenges by investigating polyethylene glycol (PEG) as a component in reactive dye ink. It was found that the PEG with longer molecular chain formed more complex coil after dissolution, which could increase ink viscosity and inhibit satellite droplets more effective. Meanwhile, the reduction of PEG concentration promoted the swelling of ink to sodium alginate (SA) film. High swelling degree and complex PEG coil could limit the ink spreading and penetration. Solid state PEG further restricted the ink spreading and penetration during the dye fixation process. Ink prepared by 3.2 wt% PEG20000 achieved no satellite droplets, the smallest spreading area and lowest permeability, and the highest dye fixation rate. Compared to commercial (CI) ink, it was evident that PEG20000/Red 218 ink exhibited less spreading and penetration, and had a higher dye fixation rate. This study introduces a promising approach for the production of high-quality, cost-effective reactive dye inks using the coil structure of polymer after dissolution.

Lyocell fiber, primarily sourced from the rapid growth of beech, eucalyptus or coniferous trees, is considered an eco-friendly low-carbon fiber. However, its susceptibility to fibrillation under wet friction conditions has significantly limited its broader application in the textile industry. To address this issue, this study employed trimethylolpropane-tri [3-(2-methylaziridin-1-yl) propionate] (TTMAP), a relatively safe tri-functional aziridine reagent, to establish a robust crosslinking network within lyocell macromolecules that had been oxidized by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). TTMAP spontaneously reacts with carboxyl groups via ring-opening reactions, eliminating the need for catalysts and providing a simple and green crosslinking method. A washing process was used to induce fibrillation, and anti-fibrillation performance was evaluated by SEM. The optimal process parameters for the TTMAP crosslinking reaction were determined as follows: a 5% concentration (owf, on weight of fabric), a temperature of 60 ℃, and a reaction time of 40 min. Notably, pH adjustment was not required for this reaction. FT-IR and XPS analyses confirmed both the oxidation of lyocell and subsequent crosslinking reaction with TTMAP. Compared to untreated lyocell, TTMAP-lyocell fabric exhibited excellent anti-fibrillation performance, even after three wash cycles. Furthermore, the dyeing properties of TTMAP-lyocell fabric remained largely unaffected, ensuring its practical applicability. This study presents a promising approach to enhancing the anti-fibrillation performance of lyocell knitted fabrics.

The growing demand for sustainable wastewater treatment emphasizes the need for eco-friendly and cost-effective solutions. This study addresses a gap in the literature by examining the role of cellulose-based materials in adsorbing pollutants such as heavy metals, synthetic dyes, and organic compounds. A bibliometric analysis was performed using VOSviewer on 730 research articles published between 2014 and 2024, sourced from the Scopus database. The analysis focused on citation patterns, bibliographic coupling, and co-occurrence mapping to identify trends in pollutant removal mechanisms, factors affecting treatment efficiency, and the application of cotton-waste adsorbents. The findings reveal three primary research clusters and highlight the significant potential of cellulose-based adsorbents for wastewater treatment. The cellulose-based materials not only offer a more sustainable solution but also contribute to reducing costs and promoting the circular economy through the repurposing of cotton or fabric waste. The study establishes cellulose-derived adsorbents as promising alternatives to conventional materials, offering a pathway for improving environmental sustainability, reducing the burden on landfills, and advancing waste management practices. It also highlights the related technologies in addressing global pollution challenges.

With the serious water contamination by frequent oil spill accidents and industrial wastewater emissions, superhydrophobic materials for oil–water separation have attracted considerable attention. In this study, an easily-prepared superhydrophobic paper was provided by using the dip-coating method, which involved depositing dopamine, copper sulfate, and dodecanethiol layer by layer on the surface of the paper to form a dense superhydrophobic surface. The prepared modified paper surface possessed excellent superhydrophobicity with a water contact angle (WCA) of 162° and an oil–water separation efficiency of more than 99% could be reached. Even after 40 cycles of oil–water separation, the separation efficiency and the water contact angle were still kept more than 95% and 150°, respectively. Additionally, the prepared superhydrophobic paper exhibited good self-cleaning properties and was highly resistant to acid, alkali, salt, and organic solutions. As a result, this study provided a new simple method to prepare functional superhydrophobic materials for oil–water separation.

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Water repellency is one of the expected functions for originally hydrophilic cotton fabrics (CFs) in various applications. Aqueous dispersions of alkylketene dimers have been used as efficient sizing chemicals in practical papermaking. In the present study, we soaked CFs in weakly cationic AKD dispersions of various AKD concentrations, squeezed them, and cured/dried the AKD dispersion-containing wet CFs at 120 °C for 10 min. Scanning electron microscopy revealed flake-like AKD structures in the AKD-treated and air-dried CFs, which mostly disappeared when the AKD-related compounds (such as the original AKD, hydrolyzed AKD, and cellulose-reacted AKD molecules present in the CFs) melted and spread during curing. The contents of the AKD-related compounds in the CFs were determined by Fourier-transform infrared spectroscopy. When a dispersion with an AKD concentration of 6.7 g/L and a pH of 4.5 was used, the cured and dried CF contained ~ 0.49% AKD-related compounds. The resulting CF sample had prolonged water-absorption times (a measure of water repellency) of > 1800s, even after 30 cycles of laundry treatment. The content of AKD-related compounds was decreased markedly from 0.49 to 0.06% and 0.01% by laundry treatment once and 30 times, respectively. Quite small amounts of AKD-related compounds remained in the CF after laundry treatment, and contributed to its high water repellency. Therefore, the AKD treatment developed in the present study offers a practical and efficient means of conferring high water repellency on CFs.

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Limited research has been conducted to understand the influence of cellulose nanocrystals (CNCs) on lipid and cholesterol digestion and absorption. This study aimed to explore and understand the ability of CNCs to modulate these processes. CNCs were obtained from palm-pressed fiber (PPF) via a green enzymatic hydrolysis method, a more environmentally friendly alternative to the traditional, acid hydrolysis. Enzymatic hydrolysis was performed using the endo-β-D-glucanase derived from Aspergillus sp. The effect of the enzyme concentration (250–1000 U/g) and reaction times (12–72 h) on CNC particle size, morphology, yield and suspension stability were studied. Enzymatic hydrolysis at a concentration 500 U/g and 72 h of incubation successfully produced needle-shaped, shortened, and non-entangled CNCs with an average diameter of 22.76 ± 5.52 nm, length of 342.55 ± 148.69 nm, an aspect ratio of ~ 15, and a crystallinity of 61.45%. Interestingly, the water (22.28 ± 0.85 g/g) and oil (15.08 ± 0.62 g/g) holding capacities of CNCs were four times higher than raw PPF (5.31 ± 0.53 g/g; 3.52 ± 0.32 g/g). The results showed increasing CNCs concentrations decreased lipase activity mobilization, increased cholesterol adsorption capability and retarded bile acid diffusion. 1% of CNCs alone inhibited 54.93% of lipase activity. 1 g of CNCs adsorbed 54.19 ± 10.70 mg of cholesterol and demonstrated a greater bile acid retardation effect than microcrystal cellulose (CNCs: 39.3 ± 10.10%: MCC: 27.05 ± 6.72%). The entrapment of lipase and bile acid by CNCs could affect lipid and cholesterol digestion, potentially benefiting digestion health applications. Furthermore, the presence of CNCs could potentially alleviate hypercholesteremia by adsorbing cholesterol and reducing bile acid diffusion. The results revealed the effectiveness of CNCs extraction from PPF through enzymatic hydrolysis and suggest that CNCs may have health benefits as a functional ingredient for developing of fat- and cholesterol-rich foods with health-promoting properties.

Lightweight, biodegradable multifunctional cellulose nanofiber (CNF) aerogel shows great potential in the fields of thermal insulation, electronic equipment and oil contaminant removal. However, its high fire risk and poor mechanical performance severely limit its extensive application. In this work, CNF aerogel with improved flame retardant and mechanical properties was successfully prepared by incorporating sepiolite (SEP) via an ice template-assisted strategy. The obtained results showed that the thermal stability and flame retardancy of CNF/SEP (CS) aerogel were significantly enhanced. For instance, the peak of heat release rate and total heat release of CS_2.5 with a mass ratio of SEP to CNFs of 5: 1 were reduced by 72.6% and 47.2%, respectively, relative to those of pure CNF aerogel. Furthermore, its limiting oxygen index value exceeded 70%, and reached UL-94 V-0 rating. Moreover, the CS_2.5 composite showed a high compressive strength of 121.1 kPa. Therefore, this study provides a facile strategy for fabricating fire safe and mechanically robust CNF aerogels, which is expected to broaden their application scope.

Although the solubility of nitrocellulose (NC) in solvents has been extensively studied, its processing properties are still not fully explored in different solvents. Research in this area can minimize the waste of resources and promote its development in industry. In this study, the effect of six solvents [diethylene glycol monomethyl ether (DM), N, N- dimethylformamide (DMF), acetone (AC), ethyl acetate (EAC), anhydrous ethanol (EtOH), and ethyl ether (DEE)] on the properties of nitrocellulose was investigated using density functional theory (DFT) simulations and experimental approaches. The results showed that the solvents, temperature, and concentration significantly impacted the rheological properties of nitrocellulose. The DM system had the highest sensitivity to the temperature, with a flow activation energy of 12.238 kJ/mol. The DMF system had the lowest viscosity, with an apparent viscosity of 2076 Pa·s. Additionally, the tensile strength of NC gun propellants was strongly influenced by the solvent used; the gun propellant prepared with EAC achieved the highest tensile strength (up to 70 MPa) and left the least solvent residue. In contrast, the DMF system exhibited a high solvent residue, likely due to its high molecular interaction energy ( − 14.48 kcal/mol). The burning process of NC gun propellants prepared by various solvents remained steady and consistent. The results provided some theoretical basis for solvent selection in the production of single-based gun propellants.

The dispersion of cellulose nanofibers (CNFs) in liquids is a crucial process in the fabrication of advanced CNF-based materials. However, there has been limited research into the quantitative evaluation of dispersed CNFs. This study presents two methods for estimating the size and porosity of fibrillated CNFs in slurries. The first method is the line-start centrifugal sedimentation method that uses a density gradient under multiple centrifugal forces. The second method is the combination of the homogenous centrifugal sedimentation method with bulk density measurements. The estimated sizes and porosities of two fibrillated CNFs are consistent between the two methods, and the obtained sizes match well with the results of the polarized optical microscope (POM) image analyses. Quantitative analysis of the dispersion states of CNFs in slurries can help investigate their correlation with the function of CNF-based products and reveal the underlying mechanism.