Surface characterization of poly(styrene-co-p-hexafluorohydroxyisopropyl-alpha-methyl styrene) copolymers by ToF-SIMS, XPS and contact angle measurements

A series of spin-cast films of poly(styrene-co-p-hexafluorohydroxyisopropyl -alpha-methyl styrene) (poly(St-co-HFMS)) copolymers were analysed by x-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectr ometry (ToF-SIMS) and contact angle measurements. The XPS results showed th at the surface chemical composition of the copolymers was the same as that of the bulk. The water contact angle decreased slightly with the HFMS conte nt, indicating that there was no fluorine segregation on the surface. This result showed that the decrease of the surface energy due to the presence o f the fluorinated groups was offset by the presence of the polar hydroxyl g roup. The characteristic peaks of poly(St-co-HFMS) could be distinguished f rom those of polystyrene in both positive and negative ToF-SIMS spectra, Ou r analyses have demonstrated that normalized peak intensities and relative intensities of the characteristic peaks can produce useful quantitative res ults. Copyright (C) 2000 John Wiley & Sons, Ltd.