Contact interaction model of liquid and solid phases

The work implements the approach formulated by B.V. Deryagin, which states for replacing the Coulomb and molecular (dispersion) forces with a system of tensions obtained on the basis of the mechanics of continuum equations using an incompressible liquid model. Interphasal activity modeling is considered from the standpoint of the equilibrium equations of mechanics of continuum using an incompressible liquid model and representing the interfacial tension tensor as a combination of spherical and deviatoric components. Analytical expressions are obtained for the components of the tension tensor depending on the wetting conditions of a solid surface with a liquid. Intermolecular interaction is determined by the value of the internal pressure of the liquid, which is variable over the interfacial layer thickness. The anisotropy of the interfacial tension tensor in the liquid-solid interfacial layer is expressed by the representation of the spherical and deviatoric components combination, which provides the equilibrium conditions for the interfacial layer. The authors propose to consider the adhesive contact as an external force effect of a solid surface on the volume phase of a liquid, leading to the formation of an interfacial tension tensor with components that are variable over the layer thickness. The authors established the nonlinear nature of the interfacial pressure distribution over the layer thickness, due to the difference in interfacial pressures in the liquid and solid phases in the direct contact zone. It is shown that the surface phenomena specificity is due to the deformation of the liquid volume in the interfacial layer, which leads to a change in intermolecular distances in different directions, which occurs with any kind of force acting on the volume phase of the liquid. The law of intermolecular forces distribution of a liquid depending on the distance is established based on the study results of a sitting drop. Expressions are obtained for determining the long-range interaction radius of liquid molecules and the thickness of the liquid-solid interfacial layer, which give a result that fits into the known estimates of the values of these quantities.