Polymer Engineering and Science, Vol.48, No.6, 1085-1093, 2008
Tocopherol-targeted membrane adsorbents prepared by hybrid molecular imprinting
A hybrid molecular imprinting technique for a tocopherol target enabled the preparation of novel membrane adsorbents. alpha-Tocopherol methacrylate was used as a functional monomer, and molecular imprinted polymer (MIP) was prepared by copolymerization with divinylbenzene. After the copolymer was granulated, several hybrid molecular imprinted membranes (HMIP) containing the polymer powders were prepared by using polymer scaffolds such as polysulfone (PSf), cellulose acetate (CA), and nylon (Ny). All HMIP membranes prepared by the phase inversion technique showed selective binding of alpha-tocopherol (alpha-Toc) over its derivative, delta-tocopherol (delta-Toc). The imprint efficiencies were 0.49 for the MIP powder and 0.60, 0.64, and 0.53 for the PSf, Ny, and CA-HMIP systems, respectively. These HMIP membranes retained their binding capacity without losing significant selectivity relative to the MIP powder. Our results demonstrated that the alpha-Toc-imprinted sites were responsible for the selective binding of the target molecules by the HMIP membranes. The membranes' binding behavior was analyzed using Scatchard plots; a heterogeneous distribution of binding sites was observed in both the MIP polymer and HMIP membranes.