STRUCTURE AND CHEMICAL SENSING APPLICATIONS OF ZIRCONIUM ACETATE SOL-GEL FILMS

Zirconium acetate polymer oxide glass thin films have been prepared by hydrolysis of zirconium(IV) n-propoxide in excess acetic acid. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy (XPS) have been used to determine the structure of the films. Results of spectroscopic analysis show that the polymer film consists of a Zr-O backbone coordinated with bridging and chelating bidentate acetate ligands. XPS data indicate that approximately 1.1 acetate ligands/Zr center are present in the film. The alcohol and alkane sorption properties of the film have been determined using a quartz crystal microbalance. Our results show that the zirconium acetate film sorbs alcohols and rejects alkanes. The alcohol affinity of the film has been attributed to hydrogen bonding interactions between the alcohol hydroxyl group and O atoms (Zr-O backbone and acetate ligands) in the zirconium acetate polymer. For alcohols larger than ethanol, repulsive interactions between the alkyl portion of the molecule and the polar film appear to limit alcohol sorption.