Preparation and adsorption property of (-)-epigallocatechin gallate surface molecularly imprinted polymer

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°C. 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.