The preparation of sterically stabilized dispersions

The preparation of nonaqueous sterically stabilized polymer latices was pioneered by Osmond and coworkers at ICI Paints Division. Their work is summarized in a comprehensive monograph (Barrett, 1975) that provides actual recipes for the successful generation of nonaqueous dispersions. Only the most general considerations need therefore be mentioned here. 

Any discussion of the role played by polymers, whether free or attached, in stabilizing colloidal dispersions must inevitably be couched in terms of polymer solution thermodynamics. The earliest, and still the best known, theory of polymer solution thermodynamics was that set forth by Flory (1941 1942) and Huggins (1941 1942a,b). Despite its serious inadequacies, which will be detailed later, the Flory-Huggins theory has had such a profound impact on polymer science that Manfred Gordon has properly referred to it as a paradigm of polymer science . It embodies concepts that remain central to the theory of polymer solution thermodynamics whilst ignoring certain features that are vital to the explanation of the entire spectrum of observed phenomena. 

The free volume theory, which was developed subsequently by Flory and coworkers, is much more elaborate in its innate construction. It attempts to rectify the omissions of the Flory-Huggins theory whilst retaining certain important elements therefrom. Whereas the Flory-Huggins theory has found wide application in the development of theories of polymeric stabilization, the free volume theory has not yet proved to be quite so productive, although it remains crucial to the understanding of the effects of temperature. Both theories will therefore be outlined in this chapter. 

The Flory-Huggins theory aims at predicting the Gibbs free energy of mixing 

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