Wettability and surface free energy of zirconia ceramics and their constituents

Measurements of contact angle for water, glycerol, formamide and diiodomethane on surfaces of zirconia ceramic stabilized with 4% magnesia, zirconia ceramic stabilized with 3% yttria, zirconia ceramic stabilized with 5% yttria, tetragonal-Y-zirconia ceramic, cubic-Y-zirconia ceramic, zirconium (IV) oxide, aluminum oxide, magnesium oxide and yttrium oxide were conducted. Using the values of contact angle, the total surface free energy of these solids, and its components resulting from different kinds of intermolecular interactions were calculated. It was found that the Lifshitz-van der Waals component of the surface free energy of zirconia ceramics only slightly depends on the amount and kind of metal oxides present in the ceramics. The acid-base component of all the studied solids is lower than 13 mJ/m(2), showing a small dependence on the kind of metal oxide. For all samples studied the electron-donor parameter of the acid-base components of the surface free energy is many times higher that electron-acceptor one. It was stated that the acid-base component probably depends on the density of OH groups on the surface of the solids studied. (C) 1999 Kluwer Academic Publishers.