以γ-氨丙基三乙氧基硅烷修饰的硅胶为载体、表没食子儿茶素没食子酸酯(EGCG)为模板分子、甲基丙烯酸为功能单体,制备了EGCG-硅胶表面分子印迹聚合物(SMIP),考察了溶剂、pH值及温度等因素对SMIP吸附EGCG性能的影响,同时运用Langmuir和Freundlich模型描述平衡状态时SMIP对EGCG的吸附行为,并对吸附过程的动力学模型和热力学模型进行预测.结果表明,以pH值为6的去离子水为溶剂,25℃下SMIP对EGCG的吸附效果最佳,吸附符合Langmuir等温吸附模型,吸附动力学符合假一级和假二级吸附速率方程,热力学是熵减过程.
Surface molecularly imprinted polymer (SMIP) was synthesized on the surface of γ-aminopropyl triethoxysilane-modified silica gel with (-)-epigallocatechin gallate (EGCG) as template molecule, and methacrylic acid as functional monomer. The effects of solvent, pH value and temperature on the adsorption capacity of EGCG on SMIP were investigated. The Langmiur and Freundlich models were used to describe the adsorption behavior of EGCG on SMIP, and the adsorption kinetics and thermodynamic models were predicted. The results showed that the optimum adsorption conditions of SMIP on EGCG were as follows: the adsorption solvent was deionized water of pH 6, and temperature 25 ℃. Langmuir model fitted to the experimental data better than Freundlich isotherm. The adsorption kinetics of EGCG on SMIP could be described by the pseudo-first-order adsorption model and the pseudo-second-order adsorption model, and the thermodynamics was an entropy reduction process.