Cellulose最新文献

Fixation and direct capture of atmospheric gases into stable, reusable products is highly desirable for environmental remediation and sustainable resource utilization. Traditionally, catalytic materials based on heavy metals or metal oxides have been extensively employed. This work studies the potential of TEMPO-oxidized cellulose nanofibrils (TCNFs) combined with non-thermal plasma for atmospheric nitrogen fixation. We specifically investigate how sodium counterions on the TCNF surfaces influence interactions with plasma-generated reactive nitrogen species in a half-diffuse coplanar surface barrier discharge (HDCSBD). Structural chemical analyses using Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Attenuated Total Reflection Fourier-transform infrared spectroscopy (ATR-FTIR), and ultraviolet–visible (UV–Vis) spectroscopy reveal that reactive plasma species, coupled with an electric field, drive selective nitrate formation. We show that sodium counterions play a crucial role in facilitating the direct formation of crystalline particles on the surface, uncovering a previously unreported plasma-driven pathway for selective nitrogen fixation. These findings provide new insights into the interplay between plasma chemistry and surface counterions, paving the way for developing functionalized cellulose nanomaterials for energy storage, catalytic applications, or agriculture.

In this work, water vapor adsorption and water vapor diffusion through low-density cellulose fiber foams of different thicknesses (10, 20, and 30 mm) were studied. The moisture sorption isotherm of the cellulose foam was determined, showing a moisture content ranging from 1.7 ± 0.1 to 15.1 ± 0.9% within a relative humidity range of 10 to 90% at 23 °C, respectively, following the GAB model for moisture adsorption. Moreover, the moisture adsorption kinetics of the cellulose foams exhibits exponential increase behavior. Adsorption kinetics depend on thickness, with the adsorption rate (k) decreasing as thickness increases. In addition, water vapor transmission rate (WVTR) experiments conducted on cellulose foams showed that water vapor diffusion flux through the structure is influenced by thickness, with WVTR values decreasing from 484 to 380 g/m²·day for thicknesses ranging from 10 to 30 mm. An innovative buffer capacity experiment has been designed and has demonstrated that cellulose foam acts as a moisture transmission retarder, functioning as a buffering (scavenger) system whose effect slightly increases with foam thickness.

To address the high flammability of eco-friendly lyocell fabric, this study developed a novel halogen-free flame retardant TGPA which was synthesized via two-step esterification of triethylene glycol, phosphoric acid, and urea. Its active NH₄⁺ groups form stable C-O-P covalent bonds with cellulose hydroxy groups. Structural characterization confirmed the successful incorporation of nitrogen and phosphorus into the fiber surface. The modified fabric exhibited self-extinguishing behavior with a markedly enhanced limiting oxygen index (LOI), while achieving a 61.8% reduction in heat release rate (HRR) and a 34.6% decrease in total heat release (THR), as well as forming a highly stable char layer. The system enables persistent flame retardancy through synergistic gas-phase radical quenching and condensed-phase charring mechanisms, maintaining performance stability after 25 laundering cycles. Mechanical properties slightly decrease but still meet practical requirements, providing an efficient, durable, and eco-friendly solution for high-safety textiles.

Hemp (Cannabis sativa L.) is widely cultivated for seed oil and fiber; however, significant portions of the plant, particularly stubble and roots, remain underutilized in the field. To address this inefficiency and explore sustainable alternatives to wood-based pulp, this study aimed to evaluate the potential of hemp stubble including stems, roots, and hurd fibers as a raw material for papermaking. Chemical composition analyses were conducted on bast and hurd fibers from different parts of the plant to assess their suitability for pulping. Distinct differences in cellulose, hemicellulose, and lignin content were identified, supporting the need for separate cooking of bast and hurd fibers, while stubble and roots were treated as whole due to their complex anatomical structure. Pulping trials showed that bast fibers produce high alpha-cellulose content and favorable optical properties, making them suitable for high-quality paper applications. Hurd fibers, due to their higher hemicellulose content, were found to be well-suited for blending with softwood kraft or recycled fibers in packaging and corrugated paper products. These results demonstrate the technical feasibility of using hemp stubble and roots in paper production. In addition to reducing agricultural waste, the use of hemp pulp supports sustainable development goals by promoting renewable raw materials and reducing dependence on wood fibers. The versatility of hemp fibers across different paper grades highlights their potential to contribute to a more circular and environmentally responsible pulp and paper industry.

Smart textiles with self-adaptive thermal-moisture regulation capabilities represent a pivotal advancement in personal thermal management. This study develops a temperature-responsive cotton fabric functionalized with poly(N-isopropylacrylamide-co-polyethylene glycol methacrylate)@zinc oxide (PNE@ZnO) composite microgels for intelligent environmental adaptation. The PNE microgel was synthesized through emulsion polymerization using N-isopropylacrylamide (NIPAM) and polyethylene glycol methacrylate (EGMA) as co-monomers, followed by hydrogen-bond-mediated interfacial assembly of ZnO nanoparticles to form PNE@ZnO nanohybrids. Comprehensive characterization demonstrated that the optimized microgel (NIPAM/EGMA molar ratio 10:1) possesses well-defined morphology and pronounced temperature-responsiveness, showing 42.3% volumetric shrinkage above the lower critical solution temperature (LCST, 34 °C) alongside a low glass transition temperature (T_g, 53.7 °C). The PNE@ZnO composite microgel was crosslinked onto cotton fabrics by 1,2,3,4-butanetetracarboxylic acid (BTCA) to ensure their durability. Remarkable thermoadaptive performance was evidenced by temperature-dependent permeability tests, heating from 25 to 40 °C triggered an 8.2% increase in air permeability and 105.6% enhancement in moisture permeability. Concurrently, the engineered fabric demonstrated superior solar reflection and scattering capabilities, achieving a 5.3 °C temperature reduction compared to untreated cotton fabric under solar irradiation. By synergistically coupling dynamic thermal-moisture regulation with passive radiative cooling, the dual-functional design establishes a platform for next-generation self-adaptive textiles. This work provides new insights into developing intelligent clothing systems that actively respond to environmental changes while maintaining energy-efficient thermal homeostasis.

Despite growing interest in enzymatic fiber modification, the impact of high-consistency enzymatic refining on the mechanical performance of paper remains unexplored. Unlike conventional low-consistency systems, high-consistency enzymatic refining offers a more energy-efficient and industrially scalable pathway for surface modification of cellulose fibers. This study investigates, under industrially relevant conditions, how high-consistency enzymatic refining of bleached kraft eucalyptus pulp with endoglucanases can support the rational design of fiber-based bioproducts. Pulp consistency (3–15 wt% ), enzyme dosage (0–300 mg/kg), and treatment time (15–60 min) were systematically varied. High-consistency enzymatic refining significantly enhanced mechanical performance: breaking length increased up to 89% and internal bonding up to 387%, without substantial freeness reduction. To enable predictive design and process optimization, machine-learning models were developed first based on process variables (consistency, time, dosage). LightGBM model achieved the best results with high predictive accuracy for property prediction (R² up to 0.955). To overcome data scarcity, a physics-informed generative augmentation strategy was implemented that incorporates freeness to generate 30 synthetic datapoints. The augmented dataset enhances predictive performance, validating the quality of the synthetic data. A physics-informed Gaussian process regression model was used to extrapolate performance at 400 mg/kg enzyme dosage, and a targeted experiment confirmed its prediction. The results suggest that high-consistency enzymatic refining enhances interfiber bonding through the generation of nanoscale fibrillar elements at the surface, influencing the final bonding of the sheet. Altogether, high-consistency enzymatic refining coupled with predictive modeling shows as a viable pathway towards producing all-cellulose materials with improved mechanical properties, while reducing energy consumption.

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The plastic sector for food packaging and medical devices is increasingly demanding new sustainable materials that ensure safety and effectively prevent microbial contamination. Ethyl cellulose (EC), a biodegradable polymer recognized as food additive E462, stands out as a promising candidate for green bioplastics. In this study, we developed a fully cellulose-based, self-standing biocomposite by combining EC plasticized with transesterified sunflower oil and bacterial cellulose (BC) nanofibers as a reinforcing phase. The incorporation of BC nanofibres led to improved mechanical and water barrier properties, while maintaining partial optical transparency. A key aspect of this work is the evaluation and characterization of the in situ formation of fatty acid ethyl esters (FAEEs) during the transesterification process, which imparts intrinsic antibacterial properties to the materials. For the first time, this antimicrobial activity is demonstrated in a cellulose-based composite against Pseudomonas aeruginosa and Staphylococcus aureus, two multidrug-resistant pathogens of critical relevance in both healthcare and food safety contexts. Antibacterial tests confirmed a bactericidal effect after 4 h, with a 6-logarithm reduction in bacterial load. The resulting biocomposite exhibited a tensile strength of ~ 1000 kPa, an elongation at break of ~ 30%, and a surface roughness of ~ 400 nm. These findings highlight the potential of this fully cellulose-based material as a sustainable antibacterial and self-standing composite for packaging, where sustainability and protection from contamination are crucial.

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In this study, we formulated a series of multifunctional hydrogels, namely Ga³⁺-GA-CMCS-Oin hydrogels (GGCO), leveraging Schiff base reactions and metal-polyphenol coordination. These GGCO hydrogels were synthesized using oxidized inulin (Oin) and gallic acid-modified carboxymethyl chitosan (GA-CMCS) as key bio-based components, and the crosslinking was achieved through Schiff base bonds between Oin’s aldehyde groups and GA-CMCS’s amino groups, eliminating the need for additional crosslinking agents. Moreover, the phenolic hydroxy groups on GA formed metal-polyphenol coordination bonds with Ga³⁺, endowing the hydrogels with potent antibacterial properties and photothermal conversion capabilities. GGCO hydrogels demonstrated exceptional multifunctionality, including superior self-healing, strong adhesion, pH sensitivity, biodegradability, and antioxidant activity. Antibacterial assessments highlighted GGCO’s photothermal antibacterial efficacy, reaching a sterilization rate as high as 99.7%. In a mouse infectious wound model, GGCO hydrogels effectively eradicated bacteria, mitigated inflammatory responses, and accelerated wound healing. Histological analysis further underscored the potential of these multifunctional GGCO hydrogels for advanced wound care solutions.

Bacterial nanocellulose is a promising biomaterial extensively used in functional foods and for drug delivery. Moreover, its characteristics can further be potentialized whether coupled with natural bio-extracts to endow antibacterial activity. Persea americana or avocado seed extracts are rich in phytochemicals and have demonstrated their antioxidant, antimicrobial and enzymatic activities, therefore encapsulating them into bacterial nanocellulose (BNC) may offer a potential release system of antibacterial avocado seed compounds. Accordingly, this study explores the in-depth insight into the influence of different bacterial nanocellulose producing strains (Komagataeibacter hansenii and Komagataeibacter xylinus) and cultivation conditions (static and dynamic cultivation, fermentation time) on the bacterial nanocellulose productivity and characteristics. The obtained bacterial nanocellulose membranes and beads were characterized in terms of chemical structure, morphology and crystallinity. More profitable and productive K. xylinus was further selected for encapsulation (up to 72.89 mg) of avocado seed extracts into bacterial nanocellulose membranes and beads in order to comprehensively evaluate the kinetic release profiles and determine their antibacterial activity against Escherichia coli and Staphylococcus aureus. Results of the study show that the bacterial nanocellulose and avocado seed extracts biohybrids represent a promising immediate (up to 17.39 mg in 1 h) and sustained (up to 35.04 mg in 48 h) release systems. Kinetic release modeling and cytotoxicity assessments confirmed controlled release behavior and biocompatibility for safe antibacterial applications in cosmetics, functional foods and drug delivery.

This study presents a pioneering approach to developing multifunctional textiles by decorating cellulosic cotton fabric with cobalt ferrite (CoFe₂O₄) nanoparticles (NPs) via a co-precipitation method, enabling both photocatalytic self-cleaning and antibacterial functionalities. X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR) analysis affirmed that decorating the fabric substrate with CoFe₂O₄ NPs was effectively performed without any change in the crystalline structure and the existing bonds within the substrate. Structural, morphological, and elemental analyses using field emission scanning electron microscopy (FESEM) revealed a coral-like nanoparticle morphology, with 30 nm particles uniformly distributed across the fiber surface. UV–vis diffuse reflectance spectroscopy (DRS) showed that the decorated fabric exhibits properties equivalent to a semiconductor with a band gap of 2.2 eV after the decoration process, enhancing its photocatalytic activity under visible light. Wettability measurements confirmed the hydrophilic nature of the decorated fabric. A notable correlation was observed between wettability, fiber morphology, and specific surface area. Under 180 min of visible light irradiation, the optimized sample achieved 91% degradation efficiency for methylene blue (MB) at a surface-to-solution ratio of 0.04 cm²/mL, which exceeded 99% when the ratio was quadrupled. The fabric also demonstrated excellent reusability, maintaining high performance over three consecutive cycles. However, the photocatalytic degradation efficiency for Rhodamine B (RhB) (38%) and Methyl Orange (MO) (38%) was significantly lower than that for MB (99%). Additionally, the sample with the highest photocatalytic activity exhibited strong antibacterial effects, reducing Gram-negative and Gram-positive colonies by over 70% and 99%, respectively, within 24 h. These remarkable photocatalytic and antibacterial performances highlight the potential of CoFe₂O₄-decorated cotton fabrics as environmentally friendly and reusable candidate materials for multifunctional textile and pollution control applications.