GA-g-PAMPS/AA/ST凝胶的制备及对亚甲基蓝吸附性能

采用微波辐射技术，通过接枝共聚反应制备了阿拉伯胶（GA）-g-2-丙烯酰胺-2-甲基丙磺酸（AMPS）/丙烯酸（AA）/海泡石黏土（ST）（GA-g-PAMPS/AA/ST）复合水凝胶，利用FTIR、XRD、SEM对复合水凝胶进行了表征，研究了水凝胶对水溶液中亚甲基蓝（MB）染料的吸附性能.结果显示：GA、ST和AA与AMPS发生了接枝共聚反应，形成具有均匀三维网络结构的复合水凝胶.0.025g水凝胶可以使体积为50mL、pH值为6.4、浓度为600mg/L的MB溶液的吸附量和吸附率分别达1146mg/g和95.5%，水凝胶具有较好的重复利用性能.Freundlich等温模型和准二级动力学模型能更好地描述吸附过程.热力学研究表明水凝胶对亚甲基蓝吸附是自发、吸热和不可逆的过程.该水凝胶可用作阳离子染料和阳离子型污染物的潜在候选生物质吸附剂.

Preparation of GA-g-PAMPS/AA/ST hydrogel and adsorption properties for methylene blue

GA-g-PAMPS/AA/ST composite hydrogel was prepared by graft copolymerization of gum arabic (GA), 2-acrylamido-2-methylpropanesulfonicacid (AMPS), acryllic acid (AA), sepiolite clay (ST) by microwave irradiation. The composite hydrogel was characterized by numerous techniques including FTIR, XRD and SEM. The adsorption propertie of the hydrogel on methylene blue (MB) in aqueous solution was studied. The hydrogel with uniform three-dimensional network was synthesized. Under the conditions of dosage of 0.025g, the volume of 50mL, pH of 6.4 and the initial concentration of 600mg/L, the adsorption capacity and removal was found to be 1146mg/g and 95.5%, respectively. Hydrogel had good repetition use performance. Meanwhile, the adsorption process described by Freundlich isothermal model and quasi-second-order kinetic equation better. Furthermore, thermodynamic studies showed that hydrogel's adsorption of methylene blue was a spontaneous, endothermic and irreversible process. Therefore, it could be used as a potential candidate biomass adsorbent for cationic dyes and pollutants.