Inverse gas chromatography: a new approach to the estimation of specific interactions

Inverse gas chromatography (IGC) has proved to be a powerful tool for chara cterisation of solid surfaces, particularly those that cannot be easily stu died by other methods, like fibres or powders. One of the magnitudes to be measured by this method is the London component of the surface free energy, which denotes the ability of the surface to interact with external materia l through Van der Waals forces. This value, is determined by measuring the retention volumes of the series of n-alkanes. The other interesting magnitu de is the polar character of the surface energy. Several methods are descri bed in the literature to evaluate this polarity or specific component of th e surface energy, not all giving concordant results. In this paper a method is proposed for the evaluation of this specific component of the surface e nergy, based on the fact, that the shift of Kovats index of polar compounds in a column, taking as reference a non polar column, is directly in relati on with the polarity of the column. Some data are given of interactions obt ained with some of the polar probes with previously described methods and t he new one. The study material is several carbon fibres, cured and uncured epoxy resins, two modified polyethylene samples and a commercial SP100 colu mn. (C) 1999 Elsevier Science BV All rights reserved.