Interaction between particles in a nonwetting liquid

Abstract

The energy analysis of formation and stability of a cavity in a liquid around the zone of contact between lyophobic particles has been carried out and the parameters of the cavity have been calculated. The receding of the liquid is thermodynamically advantageous for contacting particles as well as for those separated by a gap H not wider than a certain value H e . In the former case the formation of the cavity is a nonactivation process, while in the latter instance it involves the overcoming of a certain activation barrier whose height (∼ H 2) reaches 10 kT at H ≈ 0.3 nm (hydrophobized glass beads in water). As the particles are being separated, the cavity remains metastable in a certain range of gap widths ( H > H e ). The diameter of the cavity and H e are much greater than the molecular sizes; the formation of the cavity gives rise to a sharp increase in the free energy of interaction between the particles, provides for their attraction at considerably greater distances than the molecular forces, and enhances the force of adhesion as against that in air.