Colloidal interaction at the air-liquid interface

In this paper, we propose a model to analyze the stability of colloidal par ticles at the air-liquid interface. The proposed model for the colloidal pa rticle interaction considers DLVO interactions and capillary, hydrophobic, and dipolar interactions between the particles. Typical values from the lit erature were assigned to most parameters included in the model. Numerical c omputation revealed the most important parameter in determining the total i nteraction is the density of dipoles at the external surface of the particl es. We have found significant differences for the pair potential between hy drophobic and hydrophilic particles. Hydrophobic particles must aggregate i n a principal minimum of the interaction potential curve while hydrophilic particles aggregate in a secondary minimum. (C) 2000 Academic Press.