Low temperature synthesis, structure and bioactivity of 2CaO center dot 3SiO(2) glass

Glasses of composition 2CaO . 3SiO(2) were prepared by means of the sol-gel route starting from tetramethyl orthosilicate and calcium nitrate tetrahydrate and the melt-quenching technique from a mixture of oxides. Their structures were compared. The infrared spectra suggest that the gel derived glass has a different structure than the corresponding melt quenched glass, having a more uniform distribution of non-bridging oxygens among the SiO4 tetrahedra. Owing to its porosity, the gel derived glass is more prone to devitrify than the melt quenched glass is. The infrared spectra relative to samples soaked in a fluid simulating the composition of the human blood plasma suggest that the gel derived glass is more bioactive than the melt quenched glass is.