Plasma desorption mass spectrometry with coincidence counting for the analysis of polymer surfaces

Abstract

Coincidence counting techniques were used in conjunction with plasma desorption mass spectrometry (PDMS) for the analysis of polymer surfaces. Both single-component and polymer-blend surfaces were examined. All of the polymers investigated yield characteristic PDMS spectra. By observing the correlations between secondary ions in the PDMS information normally not available was obtained on the chemical structure of the polymers. Also, we were able to determine the yield of various secondary ions without knowledge of the number of primary ions striking the surface. The yield information was useful for determining the surface and bulk concentrations of the components of the blends. It was found that the surface concentration of poly(styrene) in the miscible poly(styrene)/poly(vinyl methyl ether) blends was the same as that in the bulk.