About seller
Alginates, a kind of naturally occurring polysaccharides, have been exploited for functional materials owing to their versatility, sustainability, nontoxicity, and relatively low cost. find more Inherent flame retardancy is one of the most attractive features of alginates, as it enables the high-value-added utilization of alginates for eco-friendly flame-retardant materials. Now, the influence of metal ions on the flame retardancy and pyrolysis behaviors of alginates has been systematically studied; besides, the applications of alginates for flame-retardant materials have been greatly developed, such as for preparing flame-retardant fibers, fabrics, aerogel composites, and foams, as well as serving as a component or modifier of functional coatings, hybrids, and additives. This review will give an overview of the recent progress and the prospects of using alginates in flame-retardant fields, which can guide the design of bio-based flame retardants and benefit the further development of more diverse applications of alginates.Polysaccharide ASK was isolated from the Abies sibirica foliage by extraction with an aqueous KOH solution. ASK was shown to contain structurally different polymers such as arabinoglucuronoxylans, xyloglucans, glucomannans, arabinogalactan-proteins (AGPs). The pectic polysaccharides were also found in the alkaline extract of ASK and were represented by regions of homogalactorunan and rhamnogalactouronan-I whose side sugar chains were made up chiefly of highly branched 1,5-α-l-arabinan. The potential couplings between those polysaccharides were examined. Our studies showed simultaneous elution of pectin, xyloglucans, arabinoglucuronoxylans and AGPs, indicating that pectins can be covalently bound to the other cell-wall polysaccharides. NMR spectroscopy results revealed that the polysaccharides obtained by ion-exchange chromatography almost had no free reducing ends. These findings corroborate the conclusion that pectin, AGPs, glucan and xylan are bound together. The existence of the covalently bound complex of pectin-xylan-xyloglucan-AGP is suggested herein. Pectin and xylan are hypothesized to be covalently linked through RG-I regions.Rhamnogalacturonan I (RG-I) enriched pectic polysaccharides were extracted from Cerasus humilis fruits (RPCF, RG-I 74.46 %). Structural characterization including FTIR, XRD, NMR, HPAEC and SEM demonstrated that RPCF was a high-methoxy acetylated pectin macromolecule with abundant arabinose and galactose side chains (DM 53.41 %, MW 1098 kDa, (Ara + Gal)/Rha 5.37 %). RPCF afforded additional lipid oxidation stability for emulsions, and exhibited significantly better emulsification performance than citrus pectin. In addition, RPCF formed a weak gel network that stabilized the emulsions (G' > G″). Interestingly, RPCF had behaviors that are divergent from those of commercial high-methoxy pectin because it demonstrated potential in forming sugar-free gels systems. Overall, Cerasus humilis is a new source of pectin rich in RG-I. RPCF can be used as a novel emulsifier with gelling and antioxidant effects, providing its alternative application as a natural emulsifier and rheological modifier in a wide range of products, including those with oil-in-water and low sugar.A bio-based pressure-responsive sensor with adjustable structural color is prepared by combining aerogel skeleton of cellulose nanocrystals (CNCs)/poly(ethylene glycol) (PEG) obtained via the ice-templating method with flexible polyacrylamide (PAAM) elastomer. The white aerogel is composed of consecutive ribbons, demonstrating chiral nematic structure. These ribbons are rearranged to be vertical to the force direction, leading to immediate appearance of the structural color when the 3D aerogel transforms to a 2D plane. Helical pitches are regulated by the PEG content that the wavelength of structural color covers up to 178 nm. There is an excellent linear correlation between pressure and transmittance of reflectance peak, and the sensitivity to pressure can be regulated by changing solid content of PAAM. Furthermore, the pressure-responsive color is still vivid after 16 cycles of compression. This flexible material with pressure-responsive structural color is promising in sensing, intelligent display, information transmission, and etc.A high-performance flexible conductive substrate is one of the key components for developing promising wearable devices. Concerning this, a sustainable, flexible, transparent, and conductive cellulose/ZnO/AZO (CZA) film was developed in this study. The cellulose was used as the transparent substrate. The added AZO was as the conductive layer and ZnO functioned as an interface buffer layer. Results showed that the interface buffer layer of ZnO effectively alleviated the intrinsic incompatibility of organic cellulose and inorganic AZO, resulting in the improvement of the performance of CZA film. In compared with the controlled cellulose/AZO (CA) film with 365 Ω/sq sheet resistance and 87% transmittance, this CZA film featured a low conductive sheet resistance of 115 Ω/sq and high transmittance of 89%, as well as low roughness of 1.85 nm Moreover, the existence of conducive ZnO buffer layer enabled the conductivity of CZA film to be stable under the bending treatment. Herein, a flexible electronic device was successfully prepared with the biomass materials, which would be available by a roll-to-roll production process.Poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOTPSS) is a conducting polymer frequently used with cellulose, to develop advanced electronic materials. To understand the fundamental interactions between cellulose and PEDOTPSS, a quartz crystal microbalance with dissipation (QCM-D) was used to study the adsorption of PEDOTPSS onto model films of cellulose-nanofibrils (CNFs) and regenerated cellulose. The results show that PEDOTPSS adsorbs spontaneously onto anionically charged cellulose wherein the adsorbed amount can be tuned by altering solution parameters such as pH, ionic strength and counterion to the charges on the CNF. Temperature-dependent QCM-D studies indicate that an entropy gain is the driving force for adsorption, as the adsorbed amount of PEDOTPSS increased with increasing temperature. Colloidal probe AFM, in accordance with QCM-D results, also showed an increased adhesion between cellulose and PEDOTPSS at low pH. AFM images show bead-like PEDOTPSS particles on CNF surfaces, while no such organization was observed on the regenerated cellulose surfaces.