Ys. Kim et Re. Tressler, MICROSTRUCTURAL EVOLUTION OF SOL-GEL-DERIVED PHOSPHOSILICATE GEL WITHHEAT-TREATMENT, Journal of Materials Science, 29(9), 1994, pp. 2531-2535
The microstructure of phosphosilicate gel prepared by a sol gel proces
s was investigated as a function of the heat-treatment temperature. Cr
ystalline phases, Si3(PO4)4 and SiP2O7, were identified in the heat-tr
eated phosphosilicate gel containing 56 mol % P2O5. It was found from
the Fourier transform infrared spectra that phosphorus enters into the
copolymer structure at approximately 600-degrees-C. The specific surf
ace area of the gel increased with the heat-treatment temperature. An
increase of the density of open pores with the heat-treatment temperat
ure was observed in the secondary electron micrographs.