Synthesis, structure and certain properties of melted and sol-gel glasses in the SiO2 and Al2O3-SiO2 systems

Abstract

SiO2 and SiO2-Al2O3 glasses containing 1 to 10 mol% Al2O3 were examined. The glasses were obtained by electrical melting of quartz and by the sol-gel method from alcoholate solutions. Using the gel glasses thin layers on soda-lime-silica glass were obtained. These layers offer good protection of glass against the corrosive action of water. DTA investigations of gel glasses were carried out showing the influence of Al2O3 in the processes of water release and combustion of organic matter. Measurements of the IR spectra and the ESCA spectra were performed and the radial distrubution function (RDF) of melted and gel glasses examined. The crystallization kinetics of these glasses was also investigated. On the basis of the obtained results the similarities and differences in the structures of glasses obtained by melting and by thermal treatment of gels are indicated.