Changes in the electronic structure of silicone rubber surfaces induced by oxygen plasma treatment

The electron spectroscopy of poly(dimethylsiloxane) (PDMS) and PDMS following oxygen plasma treatment and subsequent exposure of the plasma-treated surface to glycine are compared. The results obtained for the Auger parameter show no significant differences, whereas the results for the valence band spectra are consistent with the changes that are expected to occur as a result of the replacement of CH3 groups by oxygen and OH groups during the plasma treatment and by the adsorption of glycine. Differences observed in line shape of the Si KLV spectra for PDMS and pure Si are attributed to the changes in the local Si environment in PDMS. The oxygen plasma treatment introduces a small shift in the local p DOS to lower binding energies and exposure of the plasma-treated surface to glycine introduces a similar small shift in the p DOS to higher binding energies. Copyright (c) 2007 John Wiley & Sons, Ltd.