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 so l-gel route starting from tetramethyl orthosilicate and calcium nitrat e tetrahydrate and the melt-quenching technique from a mixture of oxid es. 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-bridgi ng oxygens among the SiO4 tetrahedra. Owing to its porosity, the gel d erived glass is more prone to devitrify than the melt quenched glass i s. The infrared spectra relative to samples soaked in a fluid simulati ng the composition of the human blood plasma suggest that the gel deri ved glass is more bioactive than the melt quenched glass is.