Surface free energy interactions of a 'thermisil' glass surface - A comparison of the thin layer wicking and contact angle techniques

Penetration measurements of selected apolar liquids were performed, i.e. octane, nonane and decane, as well as of polar liquids, i.e. water and formamide, in a thin porous layer of powdered thermisil deposited on a glass plate. On the basis of the relationships obtained and the approach of van Oss et al., the surface free energy components,i.e. the apolar Lifshitz/van der Waals and acid-base electron donor and acceptor, were determined for thermisil. To verify the values thus obtained, the contact angles of alpha-bromonaphthalene, diiodomethane, water, glycerol, ethylene glycol and formamide were measured on thermisil plates, on the basis of which the surface free energy components were again calculated. A relatively good compatibility for both the apolar and acid-base components was obtained by using the two different measurement techniques.