On the Stabilizing Effect of Surfactants Adsorption Layers

Cohesion forces in contacts of discrete spherical particles (having either hydrophilic or hydrophobic surface) were measured directly in aqueous or heptane solutions. It is shown that the stabilizing action of tensides in the hydrophobic particle system was brought about by a two-dimensional pressure of the adsorbed tenside which is easily removed · from the contact zone of the particle. The stabilizing action of tensides in the hydrophilic particle systems is a consequence of the formation of a mechanical barrier which has a high apparent strength due to the adsorbed layer on the solid surface