A potassium heptagermanate (K2O7GeO2) gel was prepared and its crystallization behavior was studied with the aid of X-ray diffraction and differential thermal analysis. The gel preparation involves hydrolysis and polycondensation of germanium ethoxide with potassium ethoxide. The gel prepared is an amorphous solid containing residues that are lost on heating. The temperatures for the gel to glass transformation are below the glass transition temperature of the glass. During the heat treatment required for the gel to glass conversion, the gel is kinetically stable to crystallization. It is then possible to convert the porous particulate gel-glass into a monolithic dense glass by sintering or hot pressing techniques without devitrification.
GEL SYNTHESIS AND CRYSTALLIZATION OF POTASSIUM HEPTAGERMANATE GLASS POWDERS
CATAURO, Michelina;
2000
Abstract
A potassium heptagermanate (K2O7GeO2) gel was prepared and its crystallization behavior was studied with the aid of X-ray diffraction and differential thermal analysis. The gel preparation involves hydrolysis and polycondensation of germanium ethoxide with potassium ethoxide. The gel prepared is an amorphous solid containing residues that are lost on heating. The temperatures for the gel to glass transformation are below the glass transition temperature of the glass. During the heat treatment required for the gel to glass conversion, the gel is kinetically stable to crystallization. It is then possible to convert the porous particulate gel-glass into a monolithic dense glass by sintering or hot pressing techniques without devitrification.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
