APPLICATION OF CORRESPONDING STATES THEORY TO THE STERIC STABILIZATION OF NON-AQUEOUS DISPERSIONS

The incipient flocculation behavior of sterically stabilized nonaqueous dispersions is discussed in terms of the corresponding states theories of polymer solutions. This has been achieved by incorporating a temperature-and pressure-dependent χ parameter into the theory of steric stabilization. It is found that the free energy of interpenetration (ΔGIM) of such dispersions consists of (i) a combinatorial contribution (ΔGIM(comb)), (ii) a contact energy dissimilarity contribution (ΔGIM(contact energy)), and (iii) a free volume dissimilarity contribution (ΔGIM(free volume)). The ΔGIM(comb) term always acts to stabilize the particles against flocculation while the ΔGIM(contact energy) and ΔGIM(free volume) terms act to flocculate the latices. In principle, flocculation at the LCFT is usually brought about by the ΔGIM(contact energy) term while flocculation at the UCFT is dominated by the ΔGIM(free volume) term. The theory is able to predict both the temperature and pressure dependence of incipient flocculation and has been applied to some recently reported experimental results. © 1979 American Chemical Society.