Model for the origin of hydrophobic force

Many investigators have measured the surface force between hydrophobic surfaces in water and observed that there was an attractive force substantially stronger than the van der Waals attractive force. The excess force was appropriately referred to as "hydrophobic force, " for which many theories have been put forth by numerous investigators. In an earlier publication (Yoon and Ravishankar, 1996), it was suggested that the hydrophobic force may be due to the interaction between the large dipoles created by the surfactants adsorbing on solid surfaces in patches (or domains). In the present work, a mathematical model was developed to further elaborate the theory. [Material: fused silica.]