Generalized Wenzel equation for contact angle of droplets on spherical rough solid substrates

Abstract

Applying Gibbs’ concept of dividing surface and dividing line, the wetting of spherical droplets on spherical rough solid substrates was studied by methods of thermodynamics. Considering the influences of line tension, a generalized Wenzel’s equation for contact angle between droplets and spherical rough solid substrates is derived. Under some assumptions, this generalized Wenzel’s equation reduces to Rusanov’s equation.