Wettability and surface free energy of zirconia ceramics and their constituents

Measurements of contact angle for water, glycerol, formamide and diiodometh ane on surfaces of zirconia ceramic stabilized with 4% magnesia, zirconia c eramic stabilized with 3% yttria, zirconia ceramic stabilized with 5% yttri a, tetragonal-Y-zirconia ceramic, cubic-Y-zirconia ceramic, zirconium (IV) oxide, aluminum oxide, magnesium oxide and yttrium oxide were conducted. Us ing the values of contact angle, the total surface free energy of these sol ids, and its components resulting from different kinds of intermolecular in teractions were calculated. It was found that the Lifshitz-van der Waals co mponent of the surface free energy of zirconia ceramics only slightly depen ds 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 e nergy is many times higher that electron-acceptor one. It was stated that t he acid-base component probably depends on the density of OH groups on the surface of the solids studied. (C) 1999 Kluwer Academic Publishers.