Gibbs' Thermodynamics of Wetting

Abstract

According to Gibbs, the interface between a solid and a fluid phase can be split into two parts, one belonging to the solid and the other to the fluid. Correspondingly, the work (ω) of forming the interface can be represented as the sum of the work (ω_s) of forming the solid surface in a vacuum and the work (ρ) of forming the fluid part of the interface. The quantity ρ, called by Gibbs the ‘superficial tension of the fluid in the contact with the solid’, can be treated either as energy or as a force, like the surface tension of a liquid. The implications of introducting ρ quantities to the thermodynamics of wetting are considered and the advantage of constructing the theory in this way is demonstrated.