Electric-controlled adsorption and surface energy of cyclodextrins

Abstract

By applying the electro-capillary rise method to control the solvent adsorption behavior for α-, β-, and γ–cyclodextrin, CD, respectively, this work showed that the voltage increase can enhance the adsorption of polar solvents, e.g. the water and formamide, while keep the adsorption of non-polar solvents, e.g. the hexane and diiodomethane, stabilization for these CDs. In terms of recorded dynamic adsorption curves, the electric-controlled surface properties of those CDs were furthermore estimated. Results showed that the increase of both the number of glucose units and voltage can enhance the surface free energy of CD due to the Lewis acid-base property of CD increased accordingly. The Lifshitz-van der Waals component has been found the main component of the surface energy of CD and was greater with the smaller number of glucose units uninfluenced by the electricity variety.