Electric Field Mediated Ion Transport Through Charged Mesoporous Membranes

Abstract

The transport of ions from aqueous solutions through a stacked Au/alpha-alumina/gamma-alumina/Au membrane under the influence of a dc potential difference is reported. The membrane shows high cation permselectivity at ionic strengths of ~1 mM at pH 4.3-6.5, which is associated with a combination of anion adsorption and double-layer overlap inside the pores of the gamma-alumina layer. The cation flux can be controlled by ionic strength, dc potential difference and pH