CONTINUUM-MECHANICS APPLIED TO A VERY THIN LIQUID-FILM - ESTIMATION OF SURFACE-TENSION FOR THE N-ALKANES

This analysis demonstrates that, at least in some cases, continuum mechanics can be successfully applied in problems involving very thin films, so long as proper recognition is given to long-range intermolecular forces and to the finite size of molecules. In this particular case, the integral mechanical energy balance is used to analyze a simple thought experiment in which a thin liquid film is slowly stretched. The result is an expression for surface tension as a function of the Hamaker constant describing liquid-liquid, long-range intermolecular forces, the molecular weight, and the liquid density, which is in good agreement with previous experimental measurements for n-alkanes.