Controlling surface properties of ultra-thin organo-clay hybrid films from cation-exchangeable surfaces to anion-exchangeable surfaces

Abstract

When amphiphilic cations are spread on a dispersion of a smectite clay, the clay nano-sheets are adsorbed on the floating molecular-layer of the amphiphilic cation to form a organo-clay hybrid monolayer. Because the positive charge density of the cation is lower than the negative charge density of the clay nano-sheet, the surface of the film transferred onto a substrate indicates cation-exchange capacity. In this work, we have successfully prepared anion-exchangeable hybrid films by increasing the positive charge density of the cation.