INVESTIGATION OF THE SURFACE CHEMICAL-STRUCTURE OF SOME BIOMEDICAL POLY(AMIDOAMINE)S USING HIGH-RESOLUTION X-RAY PHOTOELECTRON-SPECTROSCOPYAND TIME-OF-FLIGHT SECONDARY-ION MASS-SPECTROMETRY

A series of poly(amidoamine) spin cast films have been analyzed by bot h high-resolution XPS and ToF-SIMS. The XPS results are in excellent a greement with those expected from the bulk polymeric structure. Differ ences between isomeric polymers were apparent in the valence band spec tra. Also, the susceptibility to X-ray-induced degradation was noted a nd studied in some of the polymers with loss of carboxylic acid groups and quaternized nitrogen being the most notable features. High-mass r esolution ToF-SIMS produced complex spectra often with numerous peaks of differing elemental composition appearing at the same nominal mass. All of the prominent signals are assigned to ions derived from simple fragmentations of each polymer. Species could be grouped easily into series of ions derived from specific portions of the polymers and impo rtant mechanistic processes deduced from the intensities of common spe cies.