Surface and Electrokinetic Properties of Clays and Other Mineral Particles, Untreated and Treated with Organic or Inorganic Cations

Abstract

The apolar (Lifshitz van der Waals)component (yLW) and the polar [electron-acceptor (y ) and electron-donor (y ) ] parameters of the surface tension of more than sixty different clay and other mineral particles or surfaces have been measured, as well as their -potentials. It is essentially the y parameter that determines the hydrophobic (^target;⩾y28 mJ/m1)or hydrophilicy ( y ^target;⩾28 mJ/mJ) character of the mineral surface.

The surface properties were measured for twelve ion exchanged smectites, as a funclion of substitution with various alkali and alkalin earth cations. The hydrophobizing influence of exchanged organic cations on the surface properties of a number of clay particles is also determined. Finally, the hydrophobizing influence of plurivalent cations is demonstrated with Ca²⁺and La ³⁺for three different negatively charged mineral particles.