Contact angles and surface forces

The modern state of the theory of wetting phenomena is considered with special attention to the approach based on the theory of surface forces. Contribution of the effects of molecular, electrostatic and short-range structural forces to wetting films stability and forming contact angles is discussed. The magnitudes of contact angles may be predicted on the basis of isotherms of disjoining pressure of wetting films that include Hamaker constants, electrical potentials of solid-liquid and liquid-gas interfaces, and experimental constants that characterize the structural forces of hydrophilic repulsion and hydrophobic attraction. The constants seem to be the same as in the case of interaction of colloidal particles. In the framework of the suggested approach, the influence of surfactants on wetting phenomena was considered.