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Glucuronoxylans have been considered as an alternative polymer for petroleum polymers in coatings, films, emulsifiers, and other industries. In this study, different molecule weight glucuronoxylans were obtained through xylanase hydrolysis. Dodecenyl succinic anhydride (DDSA) was used as a modifying agent to functionalize glucuronoxylans. At the same degree of substitution (DS), higher molecule weight glucuronoxylans led to better emulsifying properties and emulsion stability. Higher molecule weight DDSA modified glucuronoxylans showed smaller droplets size, lower zeta potential, higher EA (emulsifying activity) and better emulsion stability. These results suggested that molecule weight has positive impact on the emulsifying properties of DDSA modified glucuronoxylans. Furthermore, DS had positive impact on the emulsifying properties of DDSA modified glucuronoxylans. [ABSTRACT FROM AUTHOR]

Cotton fiber is favored by people because of its good moisture absorption, heat preservation, soft feel, comfortable wearing and other excellent performance. In recent years, due to the destruction of the ozone layer, the intensity of ultraviolet radiation at ground level has increased. Cotton fiber will degrade under long time ultraviolet irradiation, which limits the outdoor application of cotton fiber. In this study, titanium dioxide (TiO2) particles were prepared on the surface of cotton fibers with the help of supercritical carbon dioxide (SCCO2) to improve the UV resistance of cotton fibers. The effects of SCCO2 treatment on the morphology, surface composition, thermal stability, photostability and mechanical properties of TiO2 were studied by Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, thermogravimetric analysis, UV-VIS spectroscopy, and single fiber test. The results showed that TiO2 particles were generated on the fiber surface, which reduced the photo-degradation rate of cotton fiber. This is because TiO2 can absorb UV rays and reduce the absorption of UV rays by the cotton fiber itself. The synthesis process of SCCO2 is simple and environmentally friendly, which provides a promising technology for the synthesis of metal nitrogen dioxide on natural plant fibers. [ABSTRACT FROM AUTHOR]

Algal polysaccharide is a natural gel polysaccharide with great application potentials in emulsification and dispersion. Its hydrophilic and hydrophobic functional groups endow it with natural amphiphilicity, which could improve the interface compatibility between heterogeneous phases. Furthermore, the algal polysaccharide with a natural gel network structure could greatly improve the stability of the sol-gel system by effectively preventing the re-aggregation between the dispersed phases in the system. This paper introduced the chemical compositions, structures and properties of algal polysaccharides, including alginate, fucoidan, carrageenan, agar, ulvan, etc. Their amphiphilic structures were originated from the functional groups on sugar units including hydrophilic groups such as carboxyls and sulfates and hydrophobic groups such as methoxyls, acetyls and proteins. The effects of the amphiphilic structures on molecular configuration, surface activity and rheological properties of algal polysaccharides and further on their applications in emulsification and dispersion were summarized. At the same time, the researches on enhancing amphiphilic properties of algal polysaccharides by physical or chemical methods were introduced. The research progress of the applications of algal polysaccharide derivatives in emulsification and dispersion was summarized. Finally, the direction of enhancing the interfacial adsorption activity of algal polysaccharides was prospected. [ABSTRACT FROM AUTHOR]

Xylan is a highly abundant plant-based biopolymer. Original xylans in plants are in an amorphous state, but deacetylated and low-branched xylan can form a crystalline structure with water molecules. The utilizations of xylan have been limited to bulk applications either with inconsistency and uncertainty or with extensive chemical derivatization due to the insufficient studies on its crystallization. The applications of xylan could be greatly broadened in advanced green materials if xylan crystals are effectively utilized. In this paper, we show a completely green production of nano-sized xylan crystals and propose their application in forming Pickering emulsions. The branches of xylan were regulated during the separation step to controllably induce the formation of xylan hydrate crystals. Xylan hydrate nanocrystals (XNCs) with a uniform size were successfully produced solely by a mild ultrasonic treatment. XNCs can be adsorbed onto oil–water interfaces at a high density to form highly stable Pickering emulsions. The emulsifying properties of XNCs were comparable to some synthetic emulsifiers and better than some other common biopolymer nanocrystals, demonstrating that XNCs have great potential in industrial emulsification. [ABSTRACT FROM AUTHOR]

Replacing catalyst supports with sustainable and degradable materials is an urgent task. Xylan is a type of abundant natural polymers with potential applications in dispersing, anchoring, and coating materials, but its material values have always been underestimated. In this study, polyethyleneimine modified dialdehyde xylan (DAX-PEI) was used as a dispersing and anchoring agent to bind Pd nanoparticles onto paper surface to produce a DAX-PEI-Pd coated paper, which was used to catalyze Suzuki-Miyaura reactions. The catalytic coated paper exhibited a good catalytic activity with a yield of 91% and a high turnover frequency (TOF) of 3300 h−1. Besides, it showed an excellent recyclability with the same catalytic coated paper being used 15 times and still having a yield of nearly 90%. This environment-friendly catalytic coated paper owns its great prospect in organic synthesis. • Xylan was oxidized, modified with PEI (DAX-PEI) and used to stabilize Pd2+. • Pd2+ was reduced by aldehydes and hydroxyls on DAX-PEI and the assistance of ethanol. • Pd nanoparticles was well dispersed and anchored on paper surface through DAX-PEI. • DAX-PEI-Pd catalytic paper showed great catalytic efficiency and high recyclability. [ABSTRACT FROM AUTHOR]