CHANGE IN SURFACE-PROPERTIES OF SOLIDS CAUSED BY GRINDING

The surface properties (i.e. the values of the Lifshitz-van der Waals (gamma(LW)) components and Lewis acid (gamma(+)) and base (gamma(-)) p arameters) of talc, calcite, dolomite, silica and zirconia, untreated and as ground powders, were determined by contact angle measurements ( directly on flat surfaces and by thin layer wicking for powders). The values of gamma(LW), gamma(+) and gamma(-) for these solids tend to ch ange after grinding; gamma(LW) and gamma(-) decreased for all these so lids and gamma(+) often increased, depending on the material.