Computational approach using Density Functional Theory (DFT) method and PM3 method, the geometry optimization, energy and binding energy of imprinted molecule with functional monomer were studied by Gaussian 03. Chlorogenic acid is taken as template molecule, and acrylamide (AM), acrylic acid (AA), 4-vinylpyridine (4-VP) and 2-vinylpyridine (2-VP) are taken as functional monomer, respectively. The order of the binding energy of chlorogenic acid with the above monomers was discussed, and the highest binding energy is AM. The molecular imprinting polymer (MIP) membranes with chlorogenic acid as template were prepared by UV irradiation polymerization method using AM, AA, 4-VP and 2-VP as functional monomer, respectively|polyvinylidene fluoride microfiltration membranes were used as support. The experimental results about measuring the adsorption of substrate on the several imprinted membranes are consistent with theoretical calculation results. Scatchard analysis showed that two non-equivalence binding sites were formed in the molecularly imprinted composite membranes under the studied concentration, the dissociation constants (K_d) of binding sites were 0.151 and 0.480 mmol/L. The adsorption and permeation experiment for substrates indicated that the imprinted composite membranes gave a higher adsorption capability for chlorogenic acid, combining quantities are 14.934 and 28.123 μmol/g.

Key words: molecularly imprinted composite membrane, computer simulation, Scatchard analysis, permeation, chlorogenic acid