ABSTRACT
This chapter discusses equilibrium liquid shapes on solid substrates that demand thermodynamic equilibria: liquid–vapor, liquid–solid and vapor–solid: If any of these mentioned equilibrium conditions is not satisfied, then the liquid is not at the equilibrium. It investigates the influence of the combined action of the B. V. Derjaguin’s pressure and capillary forces on the equilibrium shapes of liquids on solid substrates. The chapter considers the properties and stability of equilibrium thin liquid films on solid substrates under either partial or complete wetting conditions. It shows that simultaneous action of the capillary pressure and the S-shaped Derjaguin’s pressure isotherm results in the formation of non-flat equilibrium liquid shapes even on smooth homogeneous solid substrates. In flat thin liquid films, the Derjaguin’s pressure acts alone and determines their thickness. In the case of equilibrium liquid drops and menisci they are supposed to be always at equilibrium with the flat films in front, with which they are in contact.
