Estimation of the free surface energies of low energy solids from contact angle measurements

Abstract

Sell and his co-workers claim that the free surface energies of low energy solids, such as 17-(perfluoroheptyl)heptadecanoic acid, can be assessed from contact angle measurements alone. Their arguments are submitted to critical examination, and the conclusion reached is that their views are fundamentally unsound. The need is stressed for direct measurement of the film pressure exerted by vapour adsorbed on the solid surface.