The present invention provides a means capable of suppressing the formation of fine particles in a method for producing a silica sol. The present invention relates to a method for producing a silica sol, including synthesizing a silica sol by, in a reaction liquid containing an alkoxysilane or a condensate thereof, water, and an alkali catalyst, allowing the alkoxysilane or condensate thereof to react with the water in the presence of the alkali catalyst, wherein the alkali catalyst is not additionally supplied after the start of the synthesis until the finish time of the synthesis, and during 90% or more of the time between when 5 minutes have elapsed from the time point when the electrical conductivity of the reaction liquid reaches a local maximum for the first time and the finish time of the synthesis, the proportion of the value of the electrical conductivity of the reaction liquid is more than 90% relative to the value of the electrical conductivity at the time when 5 minutes have elapsed from the time point when the local maximum is reached.

An additive capable of suppressing generation of free water from a cement slurry even under a high temperature environment of 150° C. or more and a silica-based additive that suppresses, in a cement slurry for cementing in oil fields and gas oil fields, free water under high temperature and high pressure environments of 100° C. or more, the silica-based additive containing an aqueous silica sol containing nanosilica particles with a true density of 2.15 g/cm.sup.3 or more and less than 2.30 g/cm.sup.3, and a cement slurry for cementing that contains the silica-based additive.

A process disclosed herein is related to the isolation and purification of substantially pure chemicals, including silica gel, sodium silicate, aluminum silicate, iron oxide, and rare earth elements (or rare earth metals, REEs), from massive industrial waste coal ash. In one embodiment, the process includes a plurality of caustic extractions of coal ash at an elevated temperature, followed by an acidic treatment to dissolve aluminum silicate and REEs. The dissolved aluminum silicate is precipitated out by pH adjustment as a solid product while REEs remain in the solution. REEs are captured and enriched using an ion exchange column. Alternatively, the solution containing aluminum silicate and REEs is heated to produce silica gel, which is easily separated from the enriched REEs solution. REEs are then isolated and purified from the enriched solution to afford substantially pure individual REE by a ligand-assisted chromatography. Additionally, a simplified process using one caustic extraction and one acidic extraction with an ion exchange process was also investigated and optimized to afford a comparable efficiency.

A process disclosed herein is related to the isolation and purification of substantially pure chemicals, including silica gel, sodium silicate, aluminum silicate, iron oxide, and rare earth elements (or rare earth metals, REEs), from massive industrial waste coal ash. In one embodiment, the process includes a plurality of caustic extractions of coal ash at an elevated temperature, followed by an acidic treatment to dissolve aluminum silicate and REEs. The dissolved aluminum silicate is precipitated out by pH adjustment as a solid product while REEs remain in the solution. REEs are captured and enriched using an ion exchange column. Alternatively, the solution containing aluminum silicate and REEs is heated to produce silica gel, which is easily separated from the enriched REEs solution. REEs are then isolated and purified from the enriched solution to afford substantially pure individual REE by a ligand-assisted chromatography. Additionally, a simplified process using one caustic extraction and one acidic extraction with an ion exchange process was also investigated and optimized to afford a comparable efficiency.

The present invention provides an enzyme-powered nanomotor, comprising a particle with a surface, an enzyme, and a heterologous molecule; characterized in that the enzyme and the heterologous molecule are discontinuously attached over the whole surface of the particle. The invention also provides the nanomotor for use in therapy, diagnosis and prognosis, in particular, for the treatment of cancer. Additionally, the invention provides the use of the nanomotor for detecting an analyte in an isolated sample.

The present invention provides an enzyme-powered nanomotor, comprising a particle with a surface, an enzyme, and a heterologous molecule; characterized in that the enzyme and the heterologous molecule are discontinuously attached over the whole surface of the particle. The invention also provides the nanomotor for use in therapy, diagnosis and prognosis, in particular, for the treatment of cancer. Additionally, the invention provides the use of the nanomotor for detecting an analyte in an isolated sample.

[Problem] To provide a new technology that enables reducibility to be maintained for a prolonged period of time.

[Solution] A composition having reducing ability, comprising a substance having reducing ability and a wet ball mill-treated product of yeast cell wall and/or a hydrothermal reaction-treated product of yeast cell wall.

[Problem] To provide a new technology that enables reducibility to be maintained for a prolonged period of time.

[Solution] A composition having reducing ability, comprising a substance having reducing ability and a wet ball mill-treated product of yeast cell wall and/or a hydrothermal reaction-treated product of yeast cell wall.

A method for reducing odor, by providing a colloidal dispersion of particles of silica having a particle size of from 3 nm to 100 nm, said particles having ions of one or more metals selected from copper, silver, zinc and iron adsorbed at the particle surface, and bringing at least one of said particles into contact with an odorous compound; and/or providing an aqueous silicate solution containing metal ions selected from ions of copper, silver, zinc and iron, and bringing at least one metal ion-carrying silicate particle formed in the solution into contact with an odorous compound. A composition for use in such a method and a product treated by such a composition.

An engineered crystalline structure created from a solution containing silica dioxide that is applied on a surface and dries forming a barrier coating on the treated surface. The formed of the barrier coating has proven to be an effective antimicrobial barrier solely with inert ingredients. Moreover, the established barrier has been shown to eradicate SARS-CoV-2 within two hours without chemical intervention. When applied to a surface and allowed to dry, a 4-6 nm crystalline-like layer of silica dioxide bonds covalently to the surface. The crystalline-like structures making up the “new” surface are invisible to the naked eye but can be observed via a high-powered electronic microscope. Once silica dioxide is applied to a surface, the crystalline-like structures contain spikes that penetrate the outer membranes and protein coats of microorganisms, rendering them dead in the case of bacteria and fungi or inactive in the case of viruses.