Hongxian Fan

Selective conversion of cotton cellulose to glucose and 5-hydroxymethyl furfural with SO42−/MxOy solid superacid catalyst

This paper presented a mild hydrothermal process for degradation of cotton cellulose with solid superacid catalyst and selective conversion of cotton cellulose to glucose and 5-hydroxymethyl furfural (HMF). Five kinds of solid superacid catalyst such as SO4(2-)/SnO2, SO4(2-)/TiO2, SO4(2-)/ZrO2, SO4(2-)/Fe2O3 and SO4(2-)/Al2O3 were prepared by impregnation method. The BET surface area of catalyst SO4(2-)/SnO2 was up to 118.8m(2)g(-1) when impregnation was performed with 1molL(-1) H2SO4 of impregnating solution at 550°C calcination temperature for 3h. It made the hydrothermal temperature of cellulose degradation decrease to 190°C successfully and suppressed the side reaction. The NH3-TPD profile of SO4(2-)/SnO2 indicated there was a wide region of stronger acid sites on the catalyst surface. The depolymerization of cotton cellulose obtained 11.0% yield and 22.0% selectivity of HMF and 26.8% yield and 53.4% selectivity of glucose, respectively. The regeneration and reuse of solid superacid catalyst were also discussed in this paper.

Direct conversion of cellulose to 1-(furan-2-yl)-2-hydroxyethanone in zinc chloride solution under microwave irradiation

Conversion of cellulose to 1-(furan-2-yl)-2-hydroxyethanone has been demonstrated in concentrated zinc chloride solution under microwave irradiation. Compared with the conventional oil-bath heating mode, microwave irradiation significantly reduced the reaction time and increased the yield of 1-(furan-2-yl)-2-hydroxyethanone. A typical degradation reaction with cellulose produced 1-(furan-2-yl)-2-hydroxyethanone in 12.0% molar yield in ZnCl(2) solution (ZnCl(2)-H(2)O ratio=2.25:1, w/w) with microwave irradiation at 600 W for 5 minutes at 135°C.

Synthesis, characterization, and in vitro release analysis of a novel glucan-based polymer carrier

A novel drug carrier was synthesized through grafting polymerization of water-insoluble glucan from cotton cellulose tailored and polyoxyethylene oxide (PEO). By changing the molar ratio of water-insoluble glucan and ethylene oxide (EO), glucan-g-PEO copolymers with different chain lengths of PEO can be obtained. The physicochemical characteristics of docetaxel (DTX)-loaded glucan-g-PEO such as micro-morphology, size, critical micelle concentration (CMC), and in vitro release of kinetic were investigated. In vitro release profiles of docetaxel (DTX)-loaded glucan-g-PEO meet first-order release kinetics via a mechanism of diffusion and polymer chain relaxation. Another significant result is that release rates of DTX can be also modulated by changing the chain lengths of the PEO segments.