Hilderbrand solubility parameter

As might be expected, the Flory-Huggins parameter x is related to the Hilderbrand solubility parameter 8. From solution theory. 

The Hilderbrand-Scatchard solubility parameter 8 (Equation 16.1) can be used to estimate the miscibility of fluorocarbons with organic solvents [11-13],... 

In the case of RO membranes, the Hilderbrand s solubihty parameter (SP) of a polymeric material can be used to select suitable polymeric materials. It has also been used for the study of PV membranes. The solubility parameter expresses the nature and magnitude of the interaction force working between molecules between the permeant molecule and the molecules of the membrane material [8]. The SP of polymers, from which RO membranes with excellent performance have been prepared, are between 24 and 35. In this range the membrane material hydrophobic/hydrophihc ratio is well balanced a low SP reflects hydrophobicity of the polymer, whereas hydrophifrcity is associated with a high SP value. 

The parameter Ajj has the units of energy per unit volume and is analogous to the square of the solubility parameter in the Scatchard-Hildebrand equation. Numerous tests of the Scatchard-Hilderbrand equation have shown that there is significance to the solubility parameter. Previously, there has been no way to interpret this type of parameter from an equation of state. This new M-VDW equation could provide this opportunity. 

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