A method for manufacturing a silica sol according to an embodiment of the present invention includes: a step of preparing a silica sol reaction liquid by hydrolyzing and polycondensing an alkoxysilane or a condensate thereof using an alkali catalyst in a solvent; and at least one of a step of concentrating the silica sol reaction liquid by an ultrasonic atomization separation method and a step of replacing the silica sol reaction liquid with water by the ultrasonic atomization separation method.

A method for manufacturing a silica sol according to an embodiment of the present invention includes: a step of preparing a silica sol reaction liquid by hydrolyzing and polycondensing an alkoxysilane or a condensate thereof using an alkali catalyst in a solvent; and at least one of a step of concentrating the silica sol reaction liquid by an ultrasonic atomization separation method and a step of replacing the silica sol reaction liquid with water by the ultrasonic atomization separation method.

Intended is to provide a cation-modified silica dispersion wherein viscosity change with lapse of time is suppressed, and also intended is to suppress the variation in performance of a product using the dispersion as a raw material (for example, a polishing agent).

A cation-modified silica raw material dispersion which is being stored after being adjusted to less than pH 7.0.

Intended is to provide a cation-modified silica dispersion wherein viscosity change with lapse of time is suppressed, and also intended is to suppress the variation in performance of a product using the dispersion as a raw material (for example, a polishing agent).

A cation-modified silica raw material dispersion which is being stored after being adjusted to less than pH 7.0.

There is provided a method for obtaining a purified aqueous solution of silicic acid containing less metal impurities such as Cu and Ni using water glass as a raw material with less number of purification steps than that in conventional methods without using any unnecessary additives. The method for producing a purified aqueous solution of silicic acid, the method comprising the steps of: (a) passing an aqueous solution of alkaline silicate having a silica concentration of 0.5% by mass or more and 10% by mass or less through a column filled with a polyamine-, iminodiacetic acid-, or aminophosphoric acid-type chelating resin, and (b) passing the aqueous solution passed in the step (a) through a column filled with a hydrogen-type cation exchange resin.

A material or biomaterial comprising silicic acid condensates having a low degree of cross-linking, and methods for its production are subject-matter of the invention. A method for the production of silicic acid structures having a low degree of cross-linking is disclosed, wherein a sol is produced, wherein further condensation is prevented when specific cross-linking of the silicic acid is reached, wherein, preferably, structures having a size of 0.5-1000 nm are produced, e.g. polyhedral structures or aggregates of the same. Further condensation can be prevented by means of mixing with a polymer. In one embodiment, this comprises nano-structured, silicon dioxide (SiO.sub.2) having a low degree of cross-linking that is embedded in a polymer matrix. The material can be used in medicine for therapeutic purposes, and can enter into direct contact with biological tissue of the body in this connection. This material herein enters into chemical, physical, and biological interactions with the corresponding biological systems. It can herein be decomposed, and can act as a supplier for the silicic acid required for metabolism. Furthermore, it can have a supportive or shielding effect. It can be present as a granulate, microparticles, fiber, and as a woven or nonwoven fabric produced therefrom, or as a layer on implants or wound dressings. The material can be used as a medical device or as a nutritional supplement.

Embodiments of the invention include methods for making silica fiber mats useful for treatment of animal wounds and tissue, as well as for other applications in industry. The fiber mats are formed via electrospinning of a sol gel produced with a silicon alkoxide reagent, such as tetraethyl ortho silicate, alcohol solvent, and an acid catalyst.

Embodiments of the invention include methods for making silica fiber mats useful for treatment of animal wounds and tissue, as well as for other applications in industry. The fiber mats are formed via electrospinning of a sol gel produced with a silicon alkoxide reagent, such as tetraethyl ortho silicate, alcohol solvent, and an acid catalyst.

The invention provides a method for improving the effectiveness of colloidal silica. The method involves removing enough charged impurities from the colloid to prevent the charged particles from causing the colloid to become a viscous gel. The method however also involves not removing too many charged particles so the silica material doesn't gel by cross-linking with itself. This method is quite effective because it recognizes that materials that have accumulated during the formation of the colloid do perform an important function, but they can perform better at a lower concentration.

The invention provides a method for improving the effectiveness of colloidal silica. The method involves removing enough charged impurities from the colloid to prevent the charged particles from causing the colloid to become a viscous gel. The method however also involves not removing too many charged particles so the silica material doesn't gel by cross-linking with itself. This method is quite effective because it recognizes that materials that have accumulated during the formation of the colloid do perform an important function, but they can perform better at a lower concentration.