Influence of the Stabilization Temperature on Textural and Structural Features and Ion Release in SiO₂−CaO−P₂O₅ Sol−Gel Glasses

Abstract

Two different SiO2−CaO−P2O5 glasses have been synthesized by the sol−gel method, and the stabilization of the gel glasses was carried out at temperatures between 500 and 800 °C. The different thermal treatments lead to changes in the structural and textural properties. When the glasses were soaked in a buffered solution, the activation energy for calcium release increased with the stabilization temperature. The changes in the silicon release were found to be closely related to the changes in textural properties and network density. The evolution of such changes depended on the chemical composition of the glasses. As an assumption, the differences in behavior between both compositions can be explained in terms of the chemical structure of the glasses. The Ca/Si ratio appears to play a fundamental role in this behavior.