ADSORPTION OF ALPHA-CYCLODEXTRINS AND BETA-CYCLODEXTRINS AT THE POLYCRYSTALLINE GOLD AND SILVER ELECTRODES

The adsorption of alpha and beta-cyclodextrins on polycrystalline gold and silver electrodes has been studied from 0.05 M KF aqueous solutions by potentiostatic pulse method. It was found that adsorption of both CDs on gold and silver is strong. The adsorption of alpha and beta-CDs on gold electrode follows a Frumkin isotherm with weak positive attractive interactions. Adsorption of both CDs on silver is described by Langmuir isotherm. It was estimated that on gold electrode at E(max) molecules of alpha and beta-CDs are oriented with the cavity parallel to the electrode surface. The behaviour of alpha and beta-CD on gold and silver is compared with the literature data on the Hg electrode.