Dissolution behaviour of a polyphosphate glass in simulated body fluid

Abstract

In this work, the dissolution behavior of a polyphosphate glass, with the composition 45P2O5·3SiO2·25K2O·15CaO·10MgO·ZnO·MnO (mol %), in simulated body fluid (SBF) at a temperature of 37 °C for different times was studied. Two powder sizes of the glass (granulation: 0.1–0.3 and 0.3–0.65 mm) and the bulk glass were investigated. The dissolution experiments were conducted under stationary conditions. Changes in the normalized mass release, normalized concentration of ions, pH values, and surface morphology were determined as a function of the dissolution time. The initial rates of glass powder dissolution and leaching of ions, as well as the diffusion coefficient of cations and the releasing rate of ions, during the hydrolysis process of glass were determined. It was shown that the investigated phosphate glass dissolves in SBF incongruently, with neither precipitation nor the formation of newly potentially toxic compounds, in a dissolution period 720 h. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 34001 and Grant no. 172004]

Keywords

• biophosphate glass
• leaching
• kinetics
• mechanism