Estimating surface energy variations of solids by inverse gas chromatography

Abstract Characterization of surface heterogeneity in polymers and solids used with polymers is important to fully understand surface and interface phenomena in polymer systems. Inverse gas chromatography (IGC) represents a convenient route to the information needed. In this work, finite volumes of vapor probes were injected to scan the retention characteristics of polymers and pigments relevant to xerographic applications. The dispersive components of surface energies and acid-base interaction potentials were determined as functions of the vapor-probe volume for a polycarbonate, polystyrene, and a styrene/4-vinyl pyridine diblock polymer, and for inorganic and organic pigments. The dispersive components of the surface energies were found to vary inversely with the injection volume. In the polymers the surface energies varied, typically, by about 20%, and the values at high injection volumes equalled those obtained by contact angle measurement. Larger surface energy variations were obtained for pigments. Substantial energy heterogeneity of acidic and basic interaction sites also was documented by the IGC technique. Keywords: Surface heterogeneitysurface energyacid/base interactionxerographyinverse gas chromatography