Removal of Bisphenol A from Aqueous Solution by Molecularly Imprinted Polymers

Uniformly sized polymeric molecularly imprinted microspheres have been synthesized by membrane emulsification and suspension polymerization of methyl methacrylate and ethyl glycol dimethacrylate in the presence of bisphenol A as a template. At the beginning the best monomer compositions were selected by bulk polymerization of eight different mixtures of monomer and crosslinking agent. For the selected compositions that had the highest affinity to bisphenol A, a two-step process composed of membrane emulsification and suspension polymerization was used. Materials prepared by the two-step process showed the higher efficiency to the bisphenol A removal than their analogues prepared by bulk polymerization. The best material was synthesized from a mixture of methyl methacrylate and ethylene glycol dimethacrylate as 4:6 in the presence of n-octane as a solvent, and with 3 wt.% of bisphenol A. The logK(BPA) value for this sample was 4.9. The experimental sorption isotherms were fitted by Scatchard plots and heterogeneity of the binding sites was determined. The selectivity of the sorbents to other phenols was demonstrated.