Textural and structural studies of sol–gel derived SiO2–CaO–P2O5–MgO glasses by substitution of MgO for CaO

The partial substitution of MgO for CaO in the ternary SiO2–CaO–P2O5 glass system was conducted by the sol–gel method and a comparison of the textural and structural properties was reported. The textural properties (specific surface area and pore size distribution) were obtained by N2-adsorption measurement and the glasses structure was elucidated by Fourier transform infrared spectroscopy. It is observed that, in general, all synthesized glasses show high specific surface area and present porous nature in mesopore region. The presence of MgO in glass composition has little influence on its textural properties, however, with increasing MgO concentration the frequency of Si–O(s,asym) group shifts towards lower energy and the absorbance intensity ratio of Si–O–NBO(Q3)/Si–O–Si(s,sym)(Q4) declines, indicating the structure modification of MgO in glass composition.