SURFACE STUDIES BY STATIC SECONDARY ION MASS-SPECTROMETRY - CLUSTER ION FORMATION STUDIED BY TANDEM MASS-SPECTROMETRIC TECHNIQUES

Poly(ethylene terephthalate) (PET) and polystyrene (PS) have been studied using static secondary ion mass spectrometry (SSIMS). A triple quadrupole analyser has been employed to investigate secondary ion fragmentation and formation mechanisms. Daughter spectra and neutral loss spectra were obtained and fragmentation patterns were deduced. Comparison of the fragmentation data obtained in the gas-phase collisionally activated dissociation (CAD) experiments with the SSIMS data suggested that formation probabilities during CAD were similar to ion formation probabilities at the solid surface during low-flux sputtering. It was concluded that low-energy gas-phase CAD processes model effectively the processes which lead to fragmentation of the polymer during low-flux sputtering.