SUSPENSION INTERACTION OF RUTILE AND ANATASE TITANIUM-DIOXIDE PIGMENTS IN ORGANIC LIQUIDS

The physical interaction between TiO2 pigment and an organic liquid has been studied by suspending its finely ground particles in 62 individual liquids. The suspension interaction of the pigment in some liquids is observed to be such that its particles remain suspended in them for hours to days. To effect such an interaction, the liquid should get adsorbed on the pigment surface. Applying the principle that materials which have cohesive energy density in close range attract each other, the data of Hansen's cohesion parameters (based on semiempirical equations and theoretical subdivision of the Hildebrand parameter, delta) of organic liquids were fed into a computer program. The output data obtained from the three-dimensional plots of spherical volumes of a suspension of the pigment have been used to characterize its surface in terms of Hansen's cohesion parameters of organic liquids in which the pigment particles remain suspended for a certain period of time. This type of characterization is applicable only to the surface and not to the bulk of the pigment.