METHOD FOR THE FABRICATION OF TRANSPARENT DENSE GLASSES OBTAINED FROM SILICONE ALKOXYDES OR METAL ALKOXYDES BY THE SOL-GEL ROUTE, AND GLASSES OBTAINED ACCORDING TO SUCH METHOD

摘要

The present invention relates to a method for fabricating transparent dense glasses based on metal alkoxydes using the sol-gel route, comprising the following steps: A) a complete hydrolysis of a solution containing one or a plurality of particular metal alkoxydes is carried out in a solvent or a mixture of organic solvents of the alkoxyde(s) by using an aqueous acid solution with a pH lower than 3; the reaction medium does not contain any complexing agent for the metal present in the alkoxyde(s); B) the organic solvent(s) and the residual alcohols are removed, and the resulting solution is concentrated by distillation under primary vacuum conditions so as to obtain a sirupy sol having a concentration of 3-10 moles/l in metal or silicon atoms; C) the sol is appropriately conditioned for the intended application; D) gelling and air drying or drying in an inert atmosphere are carried out at a temperature lower than 70 °C; E) the glass may be air annealed or annealed in an inert atmosphere at a temperature lower than 500 °C.