Surface properties of silver doped titanium oxide films

Silver doped titanium oxide coatings for biomedical application were prepared by ion beam assisted deposition in an oxygen atmosphere. X-Ray photoelectron spectroscopy (XPS) was used to examine the chemical states and composition. Critical surface tension, dispersive and polar components of the surface energy were investigated by contact angle analysis. The influence of experimental conditions on the chemical states, composition and surface energy were investigated. The chemical state of silver was not affected by the process parameters and silver existed always in metallic state. XPS analysis confirmed the presence of TiO, Ti2O3 and TiO2, and the concentrations of the different oxidation states were influenced by the deposition rate of Ti and Ag. The oxygen flow rate had only a minor influence. On the other hand, dispersive and polar components of the surface energy were significantly affected by the oxygen atmosphere. The results also showed that samples with a higher concentration of silver exhibited a somewhat larger critical surface tension. (C) 2001 Elsevier Science B.V. All rights reserved.