Structural Analysis of 65ZnO–30P₂O₅–5Nb₂O₅ Invert Glass Using X-ray Photoelectron Spectroscopy

Abstract

The 65ZnO–30P₂O₅–5Nb₂O₅ (ZnPNbO) glass is one of the promising candidate antibacterial biomaterials; it is a safe material since the release of Zn²⁺ ions from the glass is well-controlled. To discuss the origin of this controlled release from the view point of its glass structure, the amount and state of bridging oxygen in the glass was examined using X-ray photoelectron spectroscopy, and compared with those in 65CaO–30P₂O₅–5Nb₂O₅ (CaPNbO) glass. The number of P–O–P bonds in ZnPNbO glass was larger and that of P–O–Nb bonds was smaller than those in CaPNbO glass. This was linked with the formation of a large number of P–O–Zn bonds. The outermost shell electron density of the cations in ZnPNbO glass decreased, and as a result, the binding energy of each element increased. These might be closely related to the controlled release of Zn²⁺ ions.