Cellulose最新文献

Triboelectric nanogenerators (TENGs) based on natural polymers gained tremendous interest for their sustainability, eco-friendliness, and biocompatibility. Despite the potential advantages of natural polymer-based TENG sensors, there are still several concerns related to their low output efficiency. This study involves the fabrication of a high-performance and eco-friendly chitosan-based TENG sensor via solvent casting method, using varied concentrations (1 wt%, 2 wt%, and 3 wt%) of graphene nanoplatelets (GNPs) as filler. Comprehensive investigations were conducted into the physicochemical, morphological, thermal, and electrical properties of the chitosan/graphene nanoplatelets (CS/GNPs) composite films. Raman analysis revealed the presence of GNPs in the CS matrix, showing enhanced I_D/I_G values for all the composites compared to pristine GNPs. The deconvoluted N1s XPS spectra unveiled the formation of CS/GNPs composites via amide linkages. Morphological analysis revealed that GNPs were embedded within the CS matrix, which tended to agglomerate at higher GNPs concentrations (3 wt%). Furthermore, the triboelectric performance of the composite films showed an outstanding open-circuit voltage (V_OC), short-circuit current (I_SC), and maximum power density of 166.25 V, 13.56 µA, and 44 mW/m² respectively, at 2 wt% GNPs concentration. The optimized CS/GNPs (2%) TENG sensor was successfully used to track real-time sports activities, distinguishing motions and basketball dribbling with different intensities and heights, respectively. Moreover, soil burial tests indicated promising biodegradation rates within six days, highlighting the significant potential of fabricated triboelectric layers in sustainable wearable technology and real-time activity monitoring.

Nanocellulose aerogels have been considered as attractive sorbents for the remediation of oil spills due to their light weight, sustainability, and abundant pore constructure. However, nanocellulose aerogels integrating high mechanical robustness and efficient oil adsorption properties are still critical challenges. Herein, a highly hydrophobic and compressible oil adsorption aerogel with special porous lamellar structures, containing cellulose nanofibril (CNF) frameworks, SiO₂@polydopamine (PDA) core-shell nanospheres, and hydrophobic modification by octadecyltrimethoxysilane (OTMS) silane long chains, is fabricated through the rapid dopamine (DA) co-deposition and silanization modification interface engineering. The core-shell particles with PDA as the binder and SiO₂ particles as the nano-sized structures were adhesively coated on CNF skeleton to introduce monolayer coatings. The synergistic effect of the SiO₂@PDA core-shell nanospheres and OTMS silane long chains significantly improved stable hydrophobicity and environmental resistance of aerogels in harsh conditions. The unique porous architecture of the aerogel can not only enhance mechanical compressibility but guide the direction of oil and organic pollutants transport. The obtained aerogels showed excellent mechanical properties with a high compressive strength of 1.23 MPa and outstanding oil adsorption performance with a high oil capture capacity of 44.63g/g. This facile strategy holds great promise to develop sustainable, compressible, and effective oil absorbents for highly efficient oil adsorbents.

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A new strategy has been designed for sustainable eco-dyeing of cotton fabric through biomass-based rabbit hair keratin modification. High dye-ability of cotton is achieved through the regulation of its surface physicochemical properties. The extracted keratin can provide substantial polar groups on the fiber surfaces, improving the binding ability of natural dyes to the cotton fabric. Additionally, the existence of aromatic amino acids in keratin enhances the UV resistance of the fabric. The optimized dyeing rate, adsorption capacity, K/S value, and UPF value of cotton fabric reach 92.0%, 25.004 mg/g, 9.1, and 57.0, respectively. Keratin modification can not adjust the surface infiltration of the fabric but does reduce the electrostatic interference during the dyeing process, which effectively increases the coloring intensity and evenness of the dyed fabrics. Theoretical calculation (DFT) indicate that introducing keratin adjusts the cellulose molecular structure, resulting in a much higher interaction energy between the modified fabric and gardenia yellow dye. The washing, soap washing fastness and chromatism (Sr) of the dyed fabric achieve grade 4, grade 3 and 0.16.

In recent years, intelligent response membrane materials have aroused considerable interest in controllable oil–water separation. However, challenges such as unstable response repeatability and easy bacterial contamination continue to hinder their effective use. Herein, a superhydrophobic fabric with pH responsiveness and antibacterial property were synthesized by combing (3-mercaptopropyl)trimethoxysilane with AgNPs and pH-responsive polymer on a fabric substrate. The fabric persisted superhydrophobicity with a WCA of 156° under natural conditions, while underwent a controlled transition of surface wettability in acidic environments. Heavy oil–water mixtures and light oil–water mixtures achieved controllable separation both before and after pH response. The fabric exhibited outstanding oil–water separation capability, achieving a separation efficiency of 98.0% and a separation flux of up to 11,025.0 L·m⁻²·h⁻¹. The pH response and oil–water separation demonstrated excellent repeatability. Specially, the pH responsiveness was maintained for up to 10 cycles, and the oil–water separation remained repeatable for up to 15 cycles. Even when tested under various environmental conditions, the superhydrophobicity was retained. Additionally, the fabric possessed remarkable antibacterial property with an efficiency reaching 90.4%. The preparation of the superhydrophobic fabric serves as a valuable reference for developing multifunctional and stable intelligent materials for oil–water separation.

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Nanosilver colloids are zero-dimensional assemblies produced either through top-to-bottom approaches or vice versa in a nanocrystalline fashion. Due to their outstanding tunable structural, morphological, optical, and functional attributes, nanosilver colloids find diverse applications in chemistry, materials, composites, textiles, and biomedical fields. We, herein, present an in-depth review of the available physical, chemical, and biological approaches to fabricate nanosilver colloids, their physicochemical attributes, and their application on cellulose fabrics for antibacterial textiles. The application of silver-based nano-finish on the cellulose fabric through its polar moieties has been undertaken in the presence of suitable crosslinkers to impart durability. The SNP synthesis methods with different reducing agents and the effectiveness of nanosilver finish with other antibacterial finishes have been compared. Over here, green-approaches have been encouraged as compared to chemical ones for the synthesis and application of silver-based nano-finishes. The effect of such treatments on the chemical, structural, textile, comfort, and antibacterial properties of cellulose and other fabrics have been discussed. The treated fabric could be characterized using various conventional and advanced analytical techniques. The antibacterial features and possible toxicity concerns associated with nanosilver-treated fabrics have also been discussed. The study concludes with recent opportunities and future suggestions in this domain.

Nonwoven glass fiber-based filters are used to study particulate matter (PM) concentration in air. In this research, the collection of PM using filters made from bleached nanocellulose fibers known for their high aspect ratio is discussed. Elemental chlorine free bleaching followed by refining using Lab valley beater and Super masscolloider has been carried out. Refining time (20 and 60 min) and clearance (0.4, 0.1, 0.01 and 0) between grinding stones were used as parameters to produce different grades of micro and nanocellulose fiber-based sheets. Refining using Lab valley beater yielded short-length whereas refining using Super masscolloider yielded long-length and high aspect ratio fibers at zero clearance. The imaging of fibers and sheets prepared using vacuum filtration were carried out using SEM. Viscosity studies of the refined pulp slurry confirmed the shear thinning behaviour. Tensile strength, burst strength, and porosity of sheets were measured to know the influence of refining parameters. Refined nanocellulose and commercial glass microfiber-based sheets were used as filters in dust capturing of PM_2.5 and PM₁₀ using dust sampler. This study reveals that micro/nanocellulose sheets obtained from Super masscolloider refining may be used an alternative to glass fiber-based sheets in capturing the fine dust (PM_2.5) having low moisture.

Green synthesis of selenium nanoparticles (SeNPs) using aqueous ginger extract was prepared for finishing of cellulosic fabrics in presence or absence of titania nanoparticles (TiO₂NPs) for antibacterial and self-cleaning applications. The synthesized nanoparticles were evaluated using transmission electron microscopy (TEM), UV–visible (UV–VIS), and dynamic light scattering (DLS) measurements. The prepared SeNPs@Ginger and TiO₂/SeNPs@Ginger suspensions were used to finish 100% cotton (CO), 50/50% cotton/polyester (CO/PET), linen, and viscose fabrics using pad/dry/curing method for acquiring antibacterial and self-cleaning properties. The finished fabrics were investigated using FTIR, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Antibacterial performance of the finished fabrics against two strains of both Gram-positive and Gram-negative bacteria was evaluated using colony counting method. The results indicated enhanced bacterial inhibition ranging from 42.96 to 86.36% depending on the kind of finished fabrics and tested bacterial species. The photodegradation of dyed fabrics with methylene blue (MB) dye under sunlight irradiation showed sharp decrease of color strength (K/S) from about 6.75 to 0.54 for SeNPs@Ginger finished fabrics and from 7.79 to 0.44 for TiO₂/SeNPs@Ginger treated ones. The photodegradation of methylene blue dyed fabrics showed enhanced self-cleaning performance of the finished fabrics.

Highly viscoelastic polyvinylidene fluoride (PVDF) nanofibers were prepared by supersonic solution blowing, resulting in the formation of nanoscale pseudo-grain boundaries that enhanced the interfacial polarization and facilitated mechanical energy harvesting in piezoelectric nanogenerators (PENGs). The addition of cellulose acetate (CA) or sodium carboxymethylcellulose (CMCNa) to the PVDF solution increased the content of electroactive γ and β phases in the PVDF/CA and PVDF/CMCNa nanofibers by factors of 2 and 3.3, respectively, and the corresponding piezoelectric potentials by factors of 3 and 6, respectively. The PVDF/CA-based PENG generated a piezopotential output of 12.5 V at a tapping force and frequency of 5 N and 5 Hz, respectively, and the PVDF/CMCNa-based PENG produced a piezopotential output of 28.6 V at a tapping force and frequency of 10 N and 7 Hz, respectively, along with a power density of 31 µW·cm⁻². The versatility of the prepared PENGs was demonstrated for a diverse range of body movements, including walking, running, writing, and finger bending. The optimal PENG can be seamlessly integrated with energy storage systems, thereby supplying power to wearable electronic instruments, such as smart sensors and health-monitoring devices.

A recent development in non-aqueous two-step (disperse and reactive) dyeing technology, minimizes water usage, eliminates the need for salt, and avoids the production of wastewater during the dyeing of polyester/cotton blend fabrics. However, an issue of color staining on cotton fibers during the disperse dyeing process has been observed. To address this issue, the mechanisms of dyeing polyester fibers and staining cotton components by disperse dyes in this process were investigated, using C.I. Disperse Red 177 as an example. It was observed that the adsorption isotherm of the disperse dye on cotton fibers resembled the Freundlich type. Moreover, as the temperature increased, the affinity between the dye and the cotton component decreased, thereby reducing the staining rate of disperse dyes on cotton fibers. High performance liquid chromatography (HPLC) analysis revealed that 22% of disperse dyes absorbed by cotton components were hydrolyzed dyes, while 78% were original dyes. This was attributed to the greater interaction energy between the original dye and the cotton fiber compared to the hydrolyzed dye. The primary interaction between disperse dyes and cotton fibers was identified as dispersion forces. From investigating the uptake, staining and hydrolysis performance of disperse dyes, the study sheds light on the mechanism of color staining behavior of disperse dye on cotton fibers, demonstrating the potential of a one-bath two-step dyeing process in non-aqueous medium dyeing system.