水热辅助表面接枝印迹法制备Cd(Ⅱ)离子印迹硅胶及其性能研究

采用水热辅助表面接枝印迹技术,以Cd(Ⅱ)离子作为模板,巯基丙基三甲氧基硅烷为功能分子,环氧氯丙烷为交联剂,在硅胶表面制备出高容量的Cd(Ⅱ)离子印迹硅胶材料,利用红外光谱仪、扫描电镜、热重分析仪等进行了表征,采用平衡吸附法研究了印迹硅胶材料的吸附性能和选择识别能力。结果表明,印迹硅胶材料和非印迹硅胶材料的最大吸附量分别为42.5和22.1mg/g;印迹硅胶材料对Cd(Ⅱ)离子具有较强的选择识别能力,对Cd(Ⅱ)离子的吸附行为更符合Langmuir模型,20min即可达到吸附平衡,符合准二级动力学方程,pH值在4～8范围内,保持了较好的吸附容量;重复使用时性能较好。

Preparation of Cd(Ⅱ)-imprinted silica by hydrothermal-assisted surface imprinting technique and its adsorption properties

Cd(Ⅱ)-imprinted silica was prepared by hydrothermal-assisted surface imprinting technique using Cd(Ⅱ) as the template,with(3-mercaptopropyl) trimethoxysilane functionalized the surface of silica as a potential sorbent for the selective adsorption Cd(Ⅱ),and characterized by FT-IR,SEM and TGA-DTA.The adsorption property and selective recognition ability of Cd(Ⅱ)-imprinted silica were studied by equilibrium-adsorption method.The results showed that the maximum static adsorption capacities of imprinted and non-imprinted silica were 42.5 and 22.1mg/g,respectively.The experimental data followed the Langmuir adsorption model.The adsorption equilibrium could be reached in 20min.Kinetic studies indicated that the adsorption followed a pseudo-second-order model.There was no influence of pH values on adsorption capacity of imprinted silica in the range of 4-8.Imprinted silica could be used repeatedly and indicated high selectivity even in the presence of the other metal ions.