Abstract: The present invention relates to a sol-gel process for the inexpensively and in large quantities agglomeration of silicon particles in a green body which is more suitable for industrial uses of silicon than the powder itself.

Abstract: The present invention relates to a sol-gel process for the inexpensively and in large quantities agglomeration of silicon particles in a green body which is more suitable for industrial uses of silicon than the powder itself.

Abstract: Method for the production of glassy monoliths via the sol-gel process, whereby the sol is gelled and dried to a Xerogel, which is sintered to a glassy monolith.

Abstract: Sol-gel process for the production of large glass monoliths, whereby tetraalkoxysilane is added to a dispersion of pyrogenically produced silica and the ratio of SiO2:TEOS is 2.6 to 5.5:1.

Abstract: Sol-gel-process to prepare aerogels comprising the preparation of a solution of a compound having the formula Xm-M-(OR)n?m, the hydrolysis of the compound to give a sol, gelation, drying, densifying and sintering. This method can be used to treat radioactive residues constituted by aqueous solutions of radioactive substances.

Abstract: Particularly shaped articles constituted by silicon oxide, as such or with suitable additives, prepared by room temperature molding according to a process comprising: preparation of a sol starting from a silicon alcoxide, or from a silicon alcoxide and at least a precursor of at least one of the additional elements; hydrolysis of the sol obtained thereby; addition of colloidal silica; pouring the resulting mixture into the desired mould; sol gelling and fast removal of the solid product; gel drying; gel densification by means of a thermal treatment at temperature ranging from 900 ° C to 1500 ° C. The articles can be used as preforms for the optic fiber spinning.