Synthesizing molecularly imprinted polymer beads for the purification of vitamin E

Molecularly imprinted polymer (MIP) beads imprinted with vitamin E (V E ) were synthesized via a two-step swelling polymerization method, using methacrylic acid (MAA) and other functional monomers together with polystyrene (PS) microspheres as the substrate. In initial trials, different functional monomers were assessed, along with a variety of solvents and imprinting ratios. The MIP MAA sample exhibited the highest performance and was characterized and also assessed with regard to V E adsorption under various experimental conditions. This material exhibited reasonably good sphericity, porosity and stability, along with an excellent adsorption capacity of 46   mg/g. This was much higher than the value for the corresponding non-imprinted polymer made with the same monomer, and 20% higher than that for an acrylamide-based MIP synthesized using a precipitation polymerization method. The core-shell structured MIP MAA also demonstrated fast adsorption kinetics, a low pressure drop and good reusability in fixed bed experiments. The V E adsorption equilibrium, selectivity, kinetics, thermodynamics and regeneration capacity of this material were also examined and are reported herein.