Experimental and Theoretical Investigation of the Structural Role of Titanium Oxide in CaO-P2O5-TiO2 Invert Glass.

Understanding the structural role of TiO2 in calcium phosphate invert glasses is key for developing a new glass design for biomedical applications. Experimental and computational analysis methods were used to investigate the impact of TiO2 substitution in these glasses. Spectroscopic analyses indicated that titanium oxide exists as both TiO4 and TiO6 units, leading to the formation of Ti-O-P bonds, in spite of depolymerization of the phosphate chains. Classical molecular dynamics showed that the presence of TiO2 influences the phosphate units and CaO polyhedral structures. The formation of the Ti-O-P bonds caused an increase in the network connectivity of the invert glasses, leading to the improvement of the glass forming ability and wettability. The addition of TiO2 to calcium phosphate invert glasses led to the introduction of bioactivity.