Abstract: Core-shell structured polymers are usually prepared by "grafting to" or "grafting from" techniques, wherein polymer supports were first modified by vinyl bonds or initiators. Success can be immediate, but more often a learning curve needs to be traversed. In this paper, direct grafting bisphenol A imprinted polymer onto poly(divinylbenzene) microspheres through precipitation polymerization is introduced. The obtained microspheres were characterized by SEM, TEM, FTIR and BET. Firstly, mono-disperse poly(divinylbenzene) microspheres of 3 μm in size were prepared by precipitation polymerization. The solvent for grafting was then optimized and it was found that the mixtures of toluene and acetonitrile (30/70, v/v) were ideal choice from the image and structure analysis of the shells. Shells of different thickness (270-840 nm), depending on the concentrations of monomers in the precursor, were then directly grafted to the microspheres by a reactive, entropic capture mechanism. The recognition ability of the microspheres was evaluated by solid-phase extraction and clear selectivity showed toward bisphenol A. The leak of bisphenol A was not found after extraction and thus these core-shell structured imprinted polymers are believed to have potential applications in trace analysis area
Template and target information: bisphenol A, BPA
Author keywords: Core-shell structures, grafting, molecular imprinting, bisphenol A, precipitation polymerization