Surface Polymerization of Organic Monomers on Cu(II)-Exchanged Hectorite

Abstract

Exposing layered silicate materials such as hectorite and montmorillonite to aniline vapor results in spontaneous surface polymerization as well as intergallery polymerization of the organic monomer. The inorganic−organic assemblies produced in these reactions possess many unique chemical and electronic properties, including the ability to function as chemical sensors. We have studied the polymerization of aniline on the surface of Cu(II)-exchanged hectorite thin films. The in-situ nucleation and growth of these polymer films is studied for the first time using the technique of scanning force microscopy (SFM) phase contrast imaging. A novel mechanism for the nucleation and growth of the surface polymer film is proposed. The availability of Cu(II) cations via defects or faults in the layered silicate structure is crucial to the formation of the subsequent conductive polymer layer.