Abstract:

A novel carboxymethyl-β-cyclodextrins (CMCD) intercalated layered double hydroxide film was prepared by in situ growth technology. The structure and chemical composition of the intercalated materials were studied by XRD and IR. The XRD analysis showed that the 001 peak of hydrotalcite moved to small angle after intercalation of CMCD, which indicated that the interlayer distance of LDH increased obviously. The asymmetric stretching band of —COO^- appeared at 1596cm^-1, which indicated that the CMCD intercalated into the LDH interlayer. Furthermore, the chiral adsorption behavior of the intercalated material to the tryptophan at series of concentration was studied primarily. The optical rotations of these filtrates were positive, which indicated that the films preferentially adsorbed the Ltryptophan. The adsorption isotherm was obtained. It was found that the enantioselective adsorption had a maximum adsorption capacity, which was caused by the chiral reorganization of interlayer immobilized CMCD. The amount of the interplay CMCD was determinate, and the enantioselective adsorption was saturable.

Key words: layered double hydroxide, carboxymethyl-β-cyclodextrin(CMCD), tryptophan, intercalation, selective absorption