Lyophobic, definition

Lyophobic colloids, ordinarily, have an electric charge of definite sign, which can be changed only by special methods. 

Until now, we have been primarily concerned with the definition and measurement of viscosity without regard to the nature of the system under consideration. Next we turn our attention to systems containing dispersed particles with dimensions in the colloidal size range. Viscosity measurements can be used to characterize both lyophobic and lyophilic systems we discuss both in the order cited. 

The system mixed with alcohol is also clear but definitely opalescent. Macrosco-pically and microscopically it is homogeneous but with the ultramicroscope particles are seen to be present. The behaviour with respect to salts is quite different even a small KCl concentration produces flocculation. The opalescent system containing alcohol therefore behaves as a ""lyophobic sol. 

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