Synthesizing Vitamin E Molecularly Imprinted Polymers via Precipitation Polymerization

Molecularly imprinted polymers (MIPs) were prepared by the precipitation polymerization process, with vitamin E as the template molecule, ethylene glycol dimethacrylate as the cross-linker, and three different functional monomers, respectively. Adsorption experiments were conducted to investigate the performance of each MIP and compared to the nonimprinted polymers (NIPs). It was found that MIPs are superior to NIPs in general, with acrylamide-based MIP showing the best adsorption capacity of 38.8 mg·g–1 and an imprinting factor of 2.6. The optimal imprinting ratio and cross-linking ratio to be 1:5 and 5:1, respectively. The Freundlich equation was found superior to Langmuir to describe the adsorption isotherm data on the MIP/NIP. The adsorption of vitamin E on the MIP was found to be a heterogeneous process and consists of two mechanisms, which were confirmed by the analysis of the thermodynamic properties of the adsorption process.