Irreversible process Ostwald ripening

As emulsions are inherently unstable, they eventually revert to the original state of two separate liquids, that is, will break or crack. In the presence of an emulsifier and other additives, this state is approached via several distinct processes, some of which are reversible such as creaming and flocculation and others irreversible such as coalescence and Ostwald ripening. Phase inversion when an oil-in-water emulsion inverts to form a water-in-oil emulsion or visa versa is a special case of irreversible instability that occurs only under well-defined conditions such as a change in emulsifier solubility due to specific interactions with additives or to a change in temperature (Fig. 3). 

These two modes are both strong functions of the electrochemical potential and the operating temperatures. Platinum particle growth can occur through Ostwald ripening in a simple surface diffusion process or through a dissolution/recrystallization process (Ross 1987). Platinum dissolution concomitant with an irreversible loss of the active metal... 

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