Comparison of the Lifshitz-van der Waals/acid-base and contact angle hysteresis approaches for determination of solid surface free energy

Total surface free energy, gamma(S)(TOT), for several solids (glass, PMMA, duralumin, steel and cadmium) was calculated from the surface free energy components: apolar Lifshitz-van der Waals, gamma(S)(LW), and acid-base electron-donor, gamma(S)(-), and electron-acceptor, gamma(S)(+). Using van Oss and coworkers' approach (Lifshitz-van der Waals/acid-base (LWAB) approach), the components were determined from advancing contact angles of the following probe liquids: water, glycerol, formamide, diiodomethane, ethylene glycol, 1-bromonaphthalene and dimethyl sulfoxide. Moreover, receding contact angles were also measured for the probe liquids, and then applying the contact angle hysteresis (CAH) approach very recently proposed by Chibowski, the total surface free energy for these solids was calculated. Although the thus determined total surface free energy for a particular solid was expected to depend on the combination of three probe liquids used (LWAB approach), as well as on the kind of the liquid used (CAH approach), surprisingly the average values of the surface free energy from the two approaches agreed very well. The results obtained indicate that both approaches can deliver some useful information about the surface free energy of a solid.