Metal ion-selective membrane prepared by surface molecular imprinting.

Surface molecular imprinting was applied to the preparation of an ion-selective polymeric membrane for the first time. The use of acrylonitrile-butadiene rubber and a porous solid support in the polymer matrix resulted in improved flexibility and mechanical strength of the imprinted membrane. The asymmetric porous structure of the membrane was observed by scanning electron microscopy. The selectivity of the zinc(II)-imprinted membrane was evaluated by competitive adsorption and permeation studies. The imprinted membrane showed higher adsorption affinity and permeation selectivity towards the imprinted zinc ion than the non-imprinted counterpart. On the basis of the results obtained, the permeation mechanism of the metal ions was considered to be hopping of metal ions on the binding sites in the membranes.