CARATTERIZZAZIONE CHIMICO-FISICA MEDIANTE XPS DI COMPOSTI DI TITANIO PER APPLICAZIONI BIOMEDICHE

摘要

In the recent years many efforts were made in order to develop new materials capable to interact with biological systems. Titanium and its compounds (alloys and oxides) are widely studied as bone replacement in orthopaedic and odontostomatologic applications. As in any biomaterial, surface properties are important to predict material behaviour in a biological environment. The chemical composition of some titanium compounds were studied by using X-ray photoelectron spectroscopy. Commercial samples of Ti with different treatments and alloy Ti6A 14V were analysed. The chemical struc- ture, due to chemical shifts of electron binding energy values, showed that all the elements were mostly oxidised. This was attributed to exposure to air after treatments. Also the quantitative analysis showed the presence of contaminants coming from the industrial manufacturing process. The surface composition was also studied in TiO_2 coatings obtained by using different techniques: 1. sol-gel (starting from alkoxide solutions) 2. plasma-spray (commercial samples). The qualitative and quantitative analysis displayed that the contamination due to adsorbed water and OH-groups in the coatings deposited by sol-gel is lower than in commercial samples. This can be used to identify a sample by just looking at the shape of the O1s peak, that can be considered a typical fingerprint of the coating. Another important fact is, that commercial TiO_2 films were also heavily contaminated with carbon, Ca, P and N. The TiO_2 film produced from sol-gel was almost stoichiometrical.%In questo lavoro vengono riportati i risultati delle misure di spettroscopia fotoelettronica XPS o ESCA effettuate su composti di titanio per applicazioni mediche. La tecnica si dimostra efficace nella valutazione sia qualitativa che quantitativa di alcune problematiche superficiali legate allo sviluppo di questi materiali.