Determination of surface tension of packings for high-performance liquid chromatography

Sorption of proteins to solids is a function of the solvent ( gamma sub(LV)), protein ( gamma sub(pv)), and solid ( gamma sub(sv)) surface tensions. gamma sub(LV) values are measured routinely and contact angle approaches have yielded reliable values of gamma sub(pv). However, only recently have methods for direct measure of surface tensions of small particles become available. The authors have determined the surface tensions of a number of surface-modified silicas with the most straightforward of these methods--the sedimentation volume technique.