新型改性壳聚糖微球的制备及其对氯酚的吸附研究

Preparation of modified chitosan microspheres and their application in adsorption of chlorophenol

采用反相悬浮法制备交联壳聚糖微球,再与庚醛反应生成Schiff′s碱,最后与NaBH4还原制得N-烷基化改性壳聚糖微球,用红外光谱和光学显微镜进行表征,并用于吸附2,4-二氯酚的研究.试验考察了微球的溶解性能,以及吸附时间、溶液pH值、氯化钠含量和2,4-二氯酚浓度等因素对吸附的影响.结果表明,庚醛改性交联壳聚糖微球不溶于水、酸和碱,对2,4-二氯酚有良好的吸附性能;在pH为6的条件下,3h吸附量达492.2mg·g-1,吸附数据符合Freundlich等温方程.

Chitosan microspheres were prepared by an inverse phase suspension method. The chitosan was modified by reducing Schiff bases formed from the reaction of n-heptaldehyde and chitosan. The microsphere structures were characterized by FTIR and photomicroscopy. The effects of adsorption conditions, such as time, pH, amount of added sodium chloride and the concentration of 2,4-dichlorophenol, on the adsorption capacity were investigated. The experimental results indicated that the microspheres were insoluble in water, and acidic and basic solutions. The microspheres adsorbed 2,4-dichlorophenol very well. In an aqueous solution at pH 6, the adsorption reached 492. 2 mg· g^-1 in 3 hours. The adsorption data of 2,4- dichlorophenol on the modified chitosan microspheres was fitted to the Freundlich isotherm.