Hybrid Films of a Clay Mineral and an Iron(II) Complex Cation Prepared by a Combined Method of the Langmuir-Blodgett and Self-Assembly Techniques

摘要

Hybrid multilayers of an amphiphilic alkylammonium cation, a clay mineral, and an iron(II) complex cation have been prepared by a combined method of the Langmuir-Blodgett and self-assembly techniques. A monolayer of the amphiphilic alkylammonium cation floating on a clay suspension is hybridized with the clay platelets at an air-suspension interface. The outer surface of the film of the ammonium cation and the clay platelets transferred from the air-suspension interface onto a substrate has cation-exchange capacity, so the Fe(II) complex cations are adsorbed onto the surface of the film by the cation-exchange reaction. By repeating these procedures, hybrid multilayers of the amphiphilic ammonium cation, the clay platelets, and the Fe(II) complex cation were successfully fabricated in a layer-by-layer way. The electronic spectra of the hybrid multilayers indicated that the density of the Fe(II) complex cation in the film could be controlled by changing the clay concentration in the suspension. The results of the X-ray diffraction measurement for the hybrid films showed that the film possessed a stable layered structure. The intensities of the second-harmonic generation from the hybrid multilayers increase in the layer number, which suggested that the hybrid multilayer should have a noncentrosymmetric geometry.