Determination of the interaction parameter g by inverse gas chromatography: an additional experimental test of the classic lattice model

Abstract

Inverse gas chromatography measurements on narrow polystyrene samples of different molecular weights have been interpreted in terms of the classic lattice model. The analysis includes a rather complex temperature dependence of the interaction parameter, g, different from the usual Flory-Huggins prediction, which only allows a linear dependence on 1 T . The extension of the simple model supplies an adequate description of the data, giving the enthalpic and entropic contributions of the interaction parameter at infinite dilution, g ∞. The different coefficients of the new temperature dependence have been determined from experimental data obtained by using chromatographic columns packed with polystyrene samples of different molecular weights, where different molecular probes have been injected. The influence of the molecular weight on these coefficients has also been studied.