INITIAL METAL FLUORIDE FORMATION AT METAL FLUOROCARBON INTERFACES/

The interaction of several perfluoroalkyl ethers [CF3OCF3, CF2OCF2OCF2 , and CF3OCF2OCF3] and an acyl fluoride [CF3OCF(CF3)CFO] with iron and aluminum surfaces has been studied with x-ray photoelectron spectrosc opy. The perfluoroalkyl ethers were found to not interact with either the clean iron surface or the clean aluminum surface. In contrast, the acyl fluoride compound was observed to readily decompose when in cont act with the clean aluminum surface. The same molecule formed a surfac e carboxylate structure when in contact the clean iron surface. Intera ctions were also observed on native oxides of aluminum and iron expose d to acyl fluoride. For the aluminum surface, the degradation of the a cyl fluoride molecule is not limited to the carbonyl group as it is fo r the iron surface. Rather, the entire molecule dissociates on the sur face.