Chemical analysis of plasma-polymerized films: The application of X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (NEXAFS) and fourier transform infrared spectroscopy (FTIR)

Selected FTIR, XPS and NEXAFS spectroscopy results obtained with films depo sited with different plasma polymerization processes and different monomers (styrene, acetylene, ethylene and butadiene) are presented. In detail MR s pectra, XPS surveys, XPS valence bands and core level signals including sha ke-up features as well as carbon K-edge absorption spectra are qualitativel y and, in some cases, semi-quantitatively considered. Information on the fi lm. formation, the chemistry of the films and the film stability against ai r exposure are derived from spectroscopic features. With styrene chemically rather well defined plasma polymer layers can be formed with rather high d eposition rates applying a pulse plasma process. Using ethylene, acetylene or butadiene as a monomer in the plasma deposition process the deposition r ates are smaller. Using these monomers plasma polymer films can be obtained with a primary chemical structure which is similar to each other but more or less different from those of the respective conventional polymers. The m ain difference between these samples is their individual concentration of u nsaturated carbon species. Finally, a technologically relevant example, i.e . a plasma deposited polymer barrier layer deposited on the inner wall of a poly(ethylene) vessel is briefly considered. (C) 2001 Elsevier Science B.V . All rights reserved.