Solution behavior of perfluoroalkanes and perfluoroalkylalkane surfactants in n-octane

Apparent molal volumes of a number of n-perfluoroalkanes (PA) and perfluoroalkylalkanes (PFAA) in n-octane have been measured at 298.15 K as a function of composition. The corresponding partial molal volumes at infinite dilution have been obtained by extrapolating the apparent molal volumes to zero composition. The results were interpreted using the hetero-SAFT-VR equation of state. The perfluoroalkylalkanes were modeled as heterosegmented diblock chains, and the cross interactions, both intra- and intermolecular, were characterized using parameters developed in earlier studies of alkane + perfluoroalkane mixtures. Through this strategy, a fully predictive approach has been developed that is able to accurately predict the volumetric behavior of the solutions of perfluoroalkylalkanes studied, without fitting to any experimental data for perfluoroalkylalkanes.