Surface energy analysis of solids and its application

Abstract

The expansion of surface tension into an additive series of terms due to the intermolecular forces, originally introduced by Fowkes, is firstly discussed. Based on this expansion, a survey is given on the analytical methods to determine the terms by means of contact angle measurements. An examination on these methods and some results on several organic polymer solids is made, and the surface pressure of adsorbed vapor is estimated. Also assuming the Berthelot’s relation on the interfacial energy, a polar term of surface tension is derived from the experimental data, in addition to the non-polar term. As an application of this analysis, the calculated interfacial energy is compared with the shearing adhesive strength between polymeric solids, which is approximated to the static friction.