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Regenerated cellulose fibers were used to produce thermoset composites from a bio-based thermoset resin synthesized from lactic acid and glycerol. The resin was impregnated into the regenerated cellulose fiber and compression molded at elevated temperature to produce thermoset composites. Different fiber alignments (unidirectional and bidirectional), different reinforcement type (warp-knitted and...
A facile “Green Synthesis” method was used to prepare silver nanoparticles (AgNPs) in bacterial cellulose (BC) nanofibers, using BC as both the reducing and protecting agents with different concentration of AgNO3 (from 0.001 to 1 M) at 0.103 MPa pressure, 121 °C for 10 min without any other chemicals. The structures and properties of AgNPs/BC were characterized by UV–Visible spectral analysis, X-ray...
The impact of field-grown transgenic trees on wood characteristics and enzymatic saccharification was evaluated. Genes 4CL and CAld5H were down regulated or overexpressed to modify the lignin content or structure (S/V ratio) on black cottonwood (Populus trichocarpa Nisqually-1). These transgenic trees were grown in the real environment and evaluated after 2 and 3 years. The results exhibited that...
Porous celluloses (PCs) were successfully prepared by a simple process of freezing the cellulose solution in ionic liquid, followed by solvent exchange and drying at normal temperature instead of the supercritical drying. PCs were composed of cellulose sheets of low crystallinity, as evidenced by SEM, XRD, TGA and FTIR, oriented into unidirectional structures when the cellulose concentration was low...
The effect of the fibrillation process through a twin-screw extruder (TSE) on properties of pulp fibers was studied, considering the degree of both fibrillation and degradation of the fibers. Never-dried refined bleached kraft pulp (NBKP) was passed through a TSE several times at a high concentration of 28 wt%. The output of fibrillated fibers had a solid content up to ca. 50 wt%, and the material...
Xylan was precipitated on bleached and unbleached softwood kraft pulps (SKPB and SKPUB), a bleached sulfite pulp, and viscose fibers to investigate the influence on physical properties of handsheets as well as to gain more detailed information of the distribution of adsorbed xylan on cellulosic surfaces. The adsorption step was carried out at constant conditions. The values of the parameters were...
Regenerated bacterial cellulose (RBC) nanocomposites with titanium dioxide nanoparticles (TiO2 NPs) were prepared with the aim to enhance the bactericidal activity and tissue regeneration properties of BC. Powdered BC was dissolved in an N-methylmorpholine-N-oxide/water (NMMO/H2O) system, TiO2 NPs were mixed into the BC solution, and RBC-TiO2 nanocomposite films were prepared by casting the composite...
Cellulose nanofibrils (CNF) form hydrogels at low concentrations. These hydrogels are held together by transient interactions such as entanglement of fibrils, non-specific ionic interactions and hydrogen bonds; and are thus vulnerable for changes in the chemical environment or the influence of mechanical forces. By a covalent crosslinking of the fibrils, stable permanent gels can be formed. In this...
1-Butyl-3-methylimidazolium chloride ([BMIM]Cl) was selected as co-solvent to dissolve cellulose and silk fibroin and the cellulose/silk fibroin blend fibers were fabricated with dry-jet wet spinning technology. The phase morphology of cellulose and silk fibroin in the blend fibers was studied by scanning electron microcopy and laser scanning confocal microscope. It is shown that the cellulose is...
The effect of the substrate (GaAs, Si, glass or Au) on the reduction of silver and gold ions in AgNO3 and HAuCl4·3H2O salts aqueous solutions was here studied. The main goal of this study was the understanding of the reduction mechanism of silver and gold ions in interaction with ultrathin cellulose films deposited on different substrates. Surface morphology was observed and measured using atomic...
Optical microscopy has long been recognized as a method to characterize the heterogeneous and complex structure of paper. With fluorescence detection, the functionality has even been extended to provide chemical selectivity, e.g. to determine the distribution of secondary modifications like coatings and fillers throughout a sheet of paper. The full spectrum of capabilities offered by fluorescence...
As functional materials, luminescent films have a wide range of applications in terms of displays, light-emitting devices, safety signs and sensors. Cellulose is the most abundant renewable resource in the world and plays an important role in the field of membrane synthesis. Here, cellulose was dissolved in 7 % NaOH/12 % urea aqueous solution, and the regenerated cellulose films were prepared in acid...
Cellulose fibres have significant importance and potential for polymer reinforcement. It is essential to modify the surface of the fibre to obtain good fibre-matrix interface. Surface treatments can increase surface roughness of the fibre, change its chemical composition and introduce new moieties that can effectively interlock with the matrix, resulting in good mechanical properties in the composites...
Chitin whiskers with diameter of 10–50 nm were prepared by a green way of mechanical-assisted enzyme hydrolysis, and several nanowhisker fractions were successfully separated by centrifugation at 3,000, 5,000, and 7,000 rpm, respectively. The size, morphology and crystalline form of as-prepared nanowhiskers were analyzed by scanning electron microscopy, transmission electron microscopy and wide angle...
Herein, we report a new strategy for the simultaneous degradation of lignocellulosic biomass and bioelectricity generation using a novel three-chamber microbial fuel cell (MFC). Oscillatoria annae, a freshwater cyanobacterium, was used for the hydrolysis of cellulose to glucose. The electrocatalytic activity of the coculture of Acetobacter aceti and Gluconobacter roseus was used to oxidize the glucose...
A cellulose-based superabsorbent exhibits excellent water absorbency and retention performance as well as biodegradability. However, the detailed biodegradation process in soil has not been monitored yet. Yellowing is another important factor affecting its appearance and storage. In this work, cellulose from flax yarn wastes (FYW) was used as the skeleton material to synthesize a cellulose-g-P(AA-co-AM)...
Poly(acrylamides) (PAMs) with various anionic and cationic charge densities from −1.64 to +0.98 meq/g but similar molecular weights were synthesized through radical polymerization. One of the aqueous PAM solutions and an aqueous dispersion of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibril (TOCN) were mixed at various PAM/TOCN weight ratios, and self-standing PAM/TOCN composite...
In order to investigate the effect of hemicellulose removal on the structural and mechanical properties of the regenerated fibers, successive alkaline treatments with increasing concentrations were employed to obtain the cellulosic materials with different hemicellulose contents. Hemicelluloses removal increased the viscosity of spinning solutions and enhance the compactness and mechanical property...
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