Preparation and structure of titanium‐containing pyrophosphate glasses prepared using the liquid‐phase method

Phosphate invert glasses (PIGs) exhibit excellent biocompatibility because of their high chemical durability and controlled ion releasability. PIGs are composed of short phosphate units such as ortho‐ and pyrophosphate. This structure makes it difficult to obtain clear glass using the melt‐quenching method. Our previous work reported that intermediate oxides (such as TiO2 and Nb2O5)‐containing PIGs exhibit good glass‐forming ability and ion dissolution controllability. This work used a liquid‐phase method to prepare PIGs at room temperature and pressure. Furthermore, TiO2 was used to control ion releasability for biomedical applications. Titanium‐containing PIGs were successfully prepared using a liquid‐phase method. Pyrophosphate and titania formed P‐O‐Ti bonds with an increasing TiO2 content in the glass, forming chain‐like structural units such as (‐O‐P‐O‐P‐O‐Ti‐O‐)n. The number of chain‐like structures increased with an increasing TiO2 content in the glass, improving the chemical durability. Hence, the ion releasability of titanium‐containing PIGs prepared using the liquid‐phase method can be controlled by the glass structure. Additionally, the PIGs exhibited good cell viability. Therefore, the PIGs are candidates for carriers of therapeutic inorganic ions for biomedical applications. Titanium‐containing phosphate invert glasses were prepared using a liquid‐phase method. The glasses were composed of ortho‐ and pyrophosphate groups. Pyrophosphate and titania formed chain‐like structures such as (‐O‐P‐O‐P‐O‐Ti‐O‐)n (denoted by QP1‐Ti). The ion‐releasing behavior can be controlled by the glass structure. The glasses exhibited good cell viability for biomedical applications.