Proton conductivity in Al-montmorillonite pillared clays
Abstract Pillared clays (PILCs) are materials derived from smectite clay minerals (2:1 phyllosilicates) in which an interlayer formation of metal oxides, acting as pillars, produces a permanent separation between the silicate layers. It is assumed that protons are generated during the thermal treatment necessary for the pillar oxide formation, as it is the case for Al-montmorillonite PILCs. We have applied the electrochemical impedance technique with the aim of studying the proton conductivity of these pillared materials. Enhancement of electrical conductivity has been observed upon adsorption of oxyethylene compounds (crown-ethers and PEO) into the PILC galleries.