SOLUBILITY PARAMETER REVISITED - AN EQUATION-OF-STATE APPROACH FOR ITS ESTIMATION

Starting from the original definition of cohesive energy density and t he solubility parameter, a systematic approach is proposed for estimat ing the latter. The potential energy E and the volume V of the system are obtained from a simple equation-of-state model. The model is able to provide estimations of E and V over extended ranges of external con ditions, for pure fluids as well as for mixtures and for simple system s as well as for highly non-ideal systems such as hydrogen-bonded syst ems, In the latter systems the approach provides estimations of the se parate components of the solubility parameter, namely, the ''hydrogen bonding'' contribution and the ''van der Waals'' contribution. The est imated solubility parameters compare favorably with widely used tabula ted values. The potential of the approach is exemplified by applying i t to the estimation of the effect of temperature and pressure on the s olubility parameters of mixtures of supercritical carbon dioxide with alcohols as entrainers. (C) 1997 Elsevier Science B.V.