Manufacture of spherical glass article

TLDR: In this paper, the authors proposed a method to produce spherical glass articles by dispersing an aqueous solvent solution of a metal alkoxide containing a small amount of hydrogen fluoride in a liquid or gaseous thermal medium to accelerate the hydrolysis of the alkoxide.

Abstract: PURPOSE:To manufacture a spherical glass article, easily, by dispersing an aqueous solvent solution of a metal alkoxide containing a small amount of hydrogen fluoride in a liquid or gaseous thermal medium to accelerate the hydrolysis of the alkoxide, and forming spherical glassy gel particles. CONSTITUTION:A metal alkoxide such as Si(OCH3)4, NaOCH3, etc. is dissolved in an aqueous medium such as hydrated methanol, etc., and a small amount (about 0.1-1mol per 1 mol of the metal alkoxide) of hydrogen fluoride is added to the solution. The obtained solution is dispersed in a liquid thermal medium (e.g. liquid paraffin) which is incompatible but dispersible with the solution, of the solution is sprayed and dispersed in a gaseous thermal medium. The hydrolysis of the metal alkoxide is accelerated in the dispersed state, and spherical glassy gel particles are formed by this process. The objective spherical glass article can be obtained by heating the glassy gel at a high temperature as needed.