壳聚糖/聚丙烯酸水凝胶的制备及对Cu2 和Cd2 的吸附性能

以丙烯酸(AA)和壳聚糖(CS)为原料，N,N''-亚甲基双丙烯酰胺(MBA)为交联剂，利用辉光放电电解等离子(GDEP)技术在水溶液中一步引发制备壳聚糖/聚丙烯酸(CS/PAA)水凝胶。采用FT-IR、XRD和SEM对水凝胶的结构和形貌进行表征，考察了溶液pH、吸附时间和初始浓度对Cu2 和Cd2 吸附的影响，探讨了水凝胶的重复利用性。结果表明，丙烯酸成功接枝到壳聚糖链上，水凝胶呈现多孔的三维网络结构，CS/PAA对Cu2 和Cd2 的吸附符合Langmuir 吸附等温式和准二级动力学模型，由Langmuir 模型得到的最大理论吸附量为161.8和327.9 mg/g，该水凝胶在EDTA-4Na溶液中具有良好的再生和重复利用性。

Preparation and Adsorption for Cu2 and Cd2 Ions of Chitosan/Poly(acrylic acid) Hydrogel

The chitosan/poly(acrylic acid) (CS/PAA) hydrogel was synthesized in aqueous solution using glow-discharge electrolysis plasma (GDEP) technique, in which chitosan and acrylic acid were used as materials, N,N''-methylenebisacrylamide (MBA) as a crosslinking agent. The structure of CS/PAA hydrogel was characterized by FT-IR, XRD and SEM. The effects of the solution pH, contacted time and initial metal concentration of Cu2 and Cd2 on the adsorption were investigated systematically. Moveover, the reusability of hydrogel was studied as well. The results showed that the acrylic acid has been successfully grafted into the chitosan backbone. The hydorgel exhibits a three-dimensional network structure with a large number of pores on the surface. The adsorption of hydrogel for Cu2 and Cd2 is agreed well with the pseudo-second-order kinetic model and the Langmuir isotherm model at room temperature. The maximum adsorption capacities of Cu2 and Cd2 obtained by Langmuir model are 161.8 and 327.9 mg/g, respectively. CS/PAA hydrogel displays excellent reusability using EDTA-4Na as eluent.