Cellulose最新文献

Chemical processes to change the hair shape can lead to damaged hair fibre. Here, we propose benign formulations based on different types of cellulose using imidazolium ionic liquids (ILs) and a commercial serum as solvents. Formulations with concentrations at 3% and 0.5% of HEC (Hydroxyethyl cellulose) and CMC (Carboxymethylcellulose) showed the best results after washing, around 10% of curling effect. Images from fluorescence microscopy enable to observe the coating layer formed on the surface of the hair fiber. ATR-FTIR corroborate the presence of functional groups of cellulose on the coated hair fiber. SEM images revealed that the treated hair fiber preserved it structural integrity, especially for the 3% CMC formulation. Those formulations also presented good mechanical wear determined by mass loss percentage. The novelty of this work is the methodology established associated with the cellulose formulation for hair modelling up to three washes.

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Solar Vapor Generation (SVG) is a new green production technology that is gaining increasing attention for obtaining fresh water from seawater or wastewater. Currently, the evaporator substrates face challenges such as complex fabrication processes, high cost, and poor biodegradability. Lignocellulosic sponge (LS), as a sustainable material, exhibits characteristics such as hydrophilicity, excellent insulation properties, lightweight nature, and low cost. It is considered a highly promising material for evaporators. In this study, LS was modified to create an efficient evaporator with excellent salt resistance. The polyvinyl alcohol/carbon black (PVA/CB) gel-based photothermal coating was introduced to enhance the water evaporation rate significantly on the surface of the lignocellulosic sponge. Subsequently, a polydimethylsiloxane (PDMS) coating was sprayed on the interfacial steam generator surface to form a hydrophobic layer, effectively resisting salt accumulation on the evaporator surface. Simultaneously, the incorporation of degreased cotton as a one-dimensional water pathway enhanced the salt ion backflow and prevented salt crystallization at the hydrophilic/hydrophobic interface. The resulting porous sponge-based photothermal evaporator (PCP-LS) achieved a high evaporation rate of up to 3.2 kg m⁻² h⁻¹ and demonstrated stable operation in high-concentration saltwater (20wt%). PCP-LS, as a cost-effective, easily fabricated, salt-tolerant, and environmentally friendly solar evaporator, holds great potential in seawater/wastewater treatment.

Ionic Liquids (ILs) have been used to address issues such as recyclability, cost-effectiveness, and tailored thermophysical properties. This is most relevant to recent efforts directed at dissolving cellulose for filament spinning and bioproduct development. Herein, we introduce a simple method to investigate how interactions between cellulose films (roughness, Rh = 37 nm) and ILs specifically 1-butyl-3-methylimidazolium acetate ([bmim][OAc]), 1-butyl-3-methylimidazolium chloride ([bmim][Cl]), 1-ethyl-3-methylimidazolium acetate ([emim][OAc]), and 1-ethyl-3-methylimidazolium chloride ([emim][Cl]), along with their water mixtures (0, 5, and 10 wt%) affect thermophysical properties relevant to cellulose dissolution (surface tension, γ; contact angle, θ; diffusivities, D; and bulk density, ρ) at 363.15 K and 0.1 MPa under argon and air atmospheres. Thermophysical properties relevant to cellulose dissolution were measured at 363.15 K and 0.1 MPa under argon (surface tension, γ, contact angle, θ), and air (diffusivities, D and bulk density, ρ) atmospheres to reveal the effect of the IL counter ions on the involved interactions with water. In general, water increased γ, θ, but reduced D, which supports experimental observations indicating the detrimental effect of water on IL-cellulose interactions. The [emim]⁺ cation (in [emim][OAc] and [emim][Cl]), produced a lower contact angle with cellulose while the interfacial properties (γ, θ, D) for ILs with the [OAc]⁻ anion were marginally affected by water. By contrast, the two ILs carrying [Cl]⁻ anions exhibited a significant reduction in D (from 11.7(cdot {10}^{-13}) to 2.9(cdot {10}^{-13} {m}^{2}{s}^{-1})) in the cation shift from [emim]⁺ to [bmim]⁺ at 363.15 K and 0.1 MPa, with 0% water content. Overall, we present a methodical approach rooted in experimental and theoretical approaches to facilitate our understanding of ionic liquids (ILs), especially within the domain of bioprocessing.

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In this work, a modified suspension polymerization method was developed to synthesize cellulose derivative hybrid polydivinylbenzene (PDVB) microspheres with particle sizes of 7–12 μm. Cellulose tris(4-methylbenzoate) (CTMB) and cellulose tris(3,5-dimethylphenylcarbamate) (CDMPC) hybrid PDVB were incorporated and well distributed in the microspheres. The chiral recognition ability of the chiral stationary phases (CSP) was evaluated by chiral high-performance liquid chromatography (HPLC) separation of 38 enantiomers with widely varied chemical structures. The influence of pore size and the loading of chiral selectors were investigated. The chiral recognition ability of the columns is comparable to that of the CHIRALCEL^® OD column and CHIRALCEL^® OJ column. For some enantiomers, the chiral selectivity of the prepared columns is even better than CHIRALPAK^®IB column and CHIRALPAK^®IJ column. In addition, the columns showed excellent stability in the basic mobile phase and organic solvents such as tetrahydrofuran (THF) and ethyl acetate (EA). This work enabled the synthesized polysaccharide-based CSPs with good chiral recognition ability and high stability.

In this study we investigate the use of in situ bioprocessing for the production and surface modification of bacterial cellulose (BC) with silicon additives. The surface properties and tensile strength of the BC were studied and compared with plain BC. The effect the modification exhibited on the survivability of the bacteria was assessed by optical density measurements and found that the addition of the modification marginally slowed growth in the case of Tetramethyl orthosilicate (TMOS) and did not affect the growth in the case of Tetraethyl orthosilicate (TEOS). Characterisation of the modified BC was carried out using FTIR, EDX and confirmed the presence of silicon in the material. The width of fibres in the microstructure of BC was measured using SEM. Two different silicon modifications were used to modify the BC, it was shown that the TMOS modification decreased the tensile strength but that the TEOS increased the tensile strength of the BC fibres compared to plain BC. In addition, we found that the washing conditions of 1% NaOH (w/v), industrial methylated spirit (IMS), and deionised water (DI) showed some impact on the properties of the samples, particularly the IMS produced a reduced contact angle in the modified samples. However, the contact angle increased in the case of TEOS modification with the NaOH wash. In conclusion this study shows a novel method of modifying BC materials in-situ using silicon additives for increased tensile strength and the potential for tuneable hydro interactions.

Polyethylene glycol (PEG) / Cellulose nanocrystal (CNC) structural colored films with good flexibility and humidity sensitive were prepared by using the evaporation-induced self-assembly method. The influence of PEG’s molecular weight and content on the change of structural color, toughening and humidity-sensitive of CNC films were systematically investigated through optical properties, morphologies, mechanical properties, and humidity responsiveness. Optical measurement results showed that the structural color and the maximum reflected light wavelength (λ_max) of CNC films were red-shifted by adding PEG. The higher the PEG molecular weight and content, the more obvious the red-shift was. Morphology characterization demonstrated the red-shift was attributed to the increasing pitch of the chiral nematic phase structure. Mechanical results showed that adding PEG significantly improved the toughness of CNC films, the higher the PEG molecular weight and content, the higher toughening effect. The toughness enhancement can be attributed to PEG being soft and having good interaction with CNCs, can be regarded as an energy dissipating binding phase which increased the energy dissipation during CNCs movement. Humidity responsiveness showed that the humidity sensitivity of CNC film was improved with PEG concentration increasing, but was independence of PEG molecular weight. Furthermore, the rheological behavior and thixotropy recovery were studied to explain the influence of PEG on the self-assembly behavior of CNCs in suspension. This study provides a foundation for regulation of CNC structural colored films with good toughness and humidity-sensitive.

The packaging industry is undergoing a major turn in its history looking for biobased, recyclable and biodegradable alternatives to petrobased products. Cellulose based materials such as paper and board can be a good solution, however, they present poor barrier properties, which are mandatory for packaging applications. In this study, all cellulose packaging with good barrier properties to grease, oxygen, water and water vapour were produced combining two innovative technologies: the wet lamination of microfibrillated cellulose (MFC) and the chromatogeny grafting. First, a thin layer of MFC (10 to 25 g/m²) was applied on a board without the use of glue in one pass. The influence of the MFC grade on the minimum MFC coat-weight required to develop grease barrier properties was investigated. Secondly, the MFC wet laminated board was grafted by chromatogeny at pilot scale. The MFC covered produced samples present excellent grease barrier properties with an oil absorption lower than 2 g/m² after 1800s (Cobb oil 1800s), a kit test of 12 and very good oxygen barrier properties. The chromatogeny grafting of fatty acids on the MFC hydroxyl groups confers barrier properties to water and water vapour to the MFC wet laminated board with a water vapour transmission rate around 36 g/(m².d). Finally, the mechanical properties of the samples and the adhesion of the MFC layer on the board were evaluated.

Supercritical Impregnation methods are becoming popular in the development of food packaging materials. Bulk functional improvements of cellulose substrates using this method may be influenced by interfacial interactions between the impregnated solutes and cellulose. Hence, an interfacial adsorption kinetics study of solute molecules onto the substrate can provide insight on bulk property development, leading to an optimized packaging material with improved functionality. Paper substrates were impregnated with two food-grade waxes: Alkyl Ketene Dimer (AKD) and Carnauba Wax (CW). Hydrophobic development was monitored over a 3-week period. A quartz crystal microbalance (QCM-D) was used to determine interfacial characteristics and behavior of each wax with cellulose, and adsorption kinetics were quantified to compare the mass transfer processes of each wax at the interface. AKD significantly contributed to the substrate’s hydrophobic development over time. CW generated mildly hydrophobic substrates only when heated. AKD strongly adhered to the cellulose fibers at the interface, and demonstrated a 3-stage kinetic adsorption process, tentatively assigned (i) diffusion through the solvent; (ii) diffusion through the substrate; and (iii) attachment onto the fibers. CW readily washed off the cellulose surface, demonstrating only the first adsorption process. The different chemical structures also impacted these behaviors, as did concentration and temperature.

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Many chemicals such as sodium chloride, sodium carbonate, synthetic dyes, oxidants, mordanting and softening agents used in clothing manufacture play a significant role in the pollution of global water resources. In view of cleaner technology, this article reviewed the effect of plasma pre-treatment on the dyeability of cotton fabric using a cleaner salt-free process. Greige cotton fabric was treated with diffuse coplanar surface barrier discharge (DCSBD) in air or nitrogen prior to the dyeing process. Three textile dyes are used in this work, reactive orange 16, direct red 81 and natural dye Acacia catechu (L.f.) Willd. Chitosan (CS) and quaternized poly[bis(2-chloroethyl) ether-alt-1,3-bis[3-(dimethylamino)propyl]urea (PQ-2) were used as cationic polymers to substitute the salt. The effect of the different treatments on the properties of the textile samples and the dyeing process was evaluated using scanning electon microscopy (SEM), ATR-FTIR, tearing strength and colorimetric measurements. The levelness and fastness properties of the obtained cotton samples were also assessed. The treated samples showed interesting colorimetric values proving the enhancement of the dye uptake without the involvement of salt or harmful additives and exhibited significant antibacterial activity.

The objective of this study was to establish a solvent-assisted salt-free dyeing method for cotton fabric utilizing commercially available reactive dyes. In this study, the feasibility of substituting water as the dyeing medium with environmentally friendly solvents, specifically ethanol (EtOH), isopropyl alcohol (IPA), and propanol (PrOH), was investigated. Eight commercial reactive dyes, each possessing distinct chemical structures, were examined with various dyeing characteristics including exhaustion, fixation, and fastness properties, in the presence of various alcohols. However, solvent-assisted dyeing exhibited comparable or enhanced color strength (K/S) values, exhaustion, and fixation rates compared to conventional aqueous dyeing. For instance, the RR35 dye demonstrated a substantial increase in K/S values with PrOH, EtOH, and IPA, ranging from 115 to 369% improvement. The substitution of alcohol for water did not affect the wash, rub, and light-color fastness properties, as these properties remained consistently excellent. Solvent-assisted salt-free dyeing of cotton fabrics offers a promising solution to address the environmental impacts of traditional water-based dyeing methods by eliminating the requirement for water and salt. Overall, this study presents a solvent-assisted salt-free dyeing technique and contributes to the field by offering detailed insights into its mechanisms and performance. Our research has the potential to reduce water consumption, eliminate salt usage, and mitigate environmental pollution.