The invention relates to a method of making hybrid organic-inorganic core-shell nano-particles, comprising the steps of a) providing colloidal organic particles comprising a synthetic polyampholyte as a template; b) adding at least one inorganic oxide precursor; and c) forming a shell layer from the precursor on the template to result in core-shell nano-particles. With this method it is possible to make colloidal organic template particles having an average particle size in the range of 10 to 300 nm; which size can be controlled by the comonomer composition of the polyampholyte, and/or by selecting dispersion conditions. The invention also relates to organic-inorganic or hollow-inorganic core-shell nano-particles obtained with this method, to compositions comprising such nano-particles, to different uses of said nano-particles and compositions, and to products comprising or made from said nano-particles and compositions, including anti-reflective coatings and composite materials.

A preparation method for a silica aerogel, comprising the following steps: A) raw material containing a solid silicon source and an alkaline solution is used to produce an aerogel precursor after mixing; and B) the aerogel precursor is dried to obtain a silica aerogel. An improved silica aerogel preparation method, comprising the following steps: A) a cation exchange resin and a silicate solution are used as raw materials and mixed; B) the mixed material is allowed to stand to obtain an aerogel precursor; and C) the aerogel precursor is dried to obtain a silica aerogel.

Provided is a method for manufacturing an aerogel blanket having improved processability by reducing manufacturing time and cost, the method including the steps of mixing a precursor material, an acid catalyst and a hydrous alcohol to prepare a sol, depositing a substrate in the sol, and reacting with a gaseous silazane-based compound to form a gel and to perform aging and surface modification reaction simultaneously to form a wet gel blanket, and drying the wet gel blanket to manufacture an aerogel blanket.

Provided is a method for manufacturing an aerogel blanket having improved processability by reducing manufacturing time and cost, the method including the steps of mixing a precursor material, an acid catalyst and a hydrous alcohol to prepare a sol, depositing a substrate in the sol, and reacting with a gaseous silazane-based compound to form a gel and to perform aging and surface modification reaction simultaneously to form a wet gel blanket, and drying the wet gel blanket to manufacture an aerogel blanket.

A colloidal silica solution which includes two or more colloidal silica compositions or suspensions having differing particle sizes and specific surface areas, the compositions or suspensions resulting in a multimodal particle size distribution in which the solution or suspension can be bimodal in nature and composed of, but not limited to, particles with a mode of 4 nm and 20 nm or composed of particles 7 nm and 12 nm. The solution or suspension can also be trimodal and composed of, but not limited to, 4 nm, 7 nm and 15 nm or 3 nm, 5 nm, and 20 nm. The solution or suspension can also include other multimodal systems which would give superior water drainage and fiber and ash retention on paper machines. The colloidal silica solution is a drainage and retention aid in the making of paper.

A method for synthesizing a pre-hydrolyzed polysilicate, wherein a polysilicate is applied as a reactant when synthesizing the pre-hydrolyzed polysilicate, and the total amount of water added in the reaction system is specified. The method is capable of omitting a condensation reaction by applying a polysilicate as a reactant, thereby significantly shortening synthesis time and reducing production costs when compared with a typical synthesis method in which alkoxysilane-based monomer compound is used as a reactant. In addition, the gelation reaction time and the weight average molecular weight can be easily controlled, and a pre-hydrolyzed polysilicate excellent in storage stability and processability can be synthesized.

A method for synthesizing a pre-hydrolyzed polysilicate, wherein a polysilicate is applied as a reactant when synthesizing the pre-hydrolyzed polysilicate, and the total amount of water added in the reaction system is specified. The method is capable of omitting a condensation reaction by applying a polysilicate as a reactant, thereby significantly shortening synthesis time and reducing production costs when compared with a typical synthesis method in which alkoxysilane-based monomer compound is used as a reactant. In addition, the gelation reaction time and the weight average molecular weight can be easily controlled, and a pre-hydrolyzed polysilicate excellent in storage stability and processability can be synthesized.

A method of producing a dispersion of irregularly shaped silica-based fine particles according to the invention includes steps (a) to (f) below: Step (a): obtaining a seed particle precursor dispersion by adjusting an aqueous alkali silicate solution so that ionic strength is 0.4 or more; Step (b): subjecting the seed particle precursor dispersion to heat-aging; Step (c): obtaining a seed particle dispersion by adding an acidic silicic acid solution to the seed particle precursor dispersion subjected to the heat-aging; Step (d): adjusting the seed particle dispersion so that the ionic strength is 0.25 or more; Step (e): subjecting the seed particle dispersion, of which SiO.sub.2 concentration and ionic strength are adjusted, to heat-aging: and Step (f): obtaining a dispersion of irregularly shaped silica-based fine particles that contains irregularly shaped silica-based fine particles by adding an acidic silicic acid solution to the seed particle dispersion subjected to the heat-aging.

A method of producing a dispersion of irregularly shaped silica-based fine particles according to the invention includes steps (a) to (f) below: Step (a): obtaining a seed particle precursor dispersion by adjusting an aqueous alkali silicate solution so that ionic strength is 0.4 or more; Step (b): subjecting the seed particle precursor dispersion to heat-aging; Step (c): obtaining a seed particle dispersion by adding an acidic silicic acid solution to the seed particle precursor dispersion subjected to the heat-aging; Step (d): adjusting the seed particle dispersion so that the ionic strength is 0.25 or more; Step (e): subjecting the seed particle dispersion, of which SiO.sub.2 concentration and ionic strength are adjusted, to heat-aging: and Step (f): obtaining a dispersion of irregularly shaped silica-based fine particles that contains irregularly shaped silica-based fine particles by adding an acidic silicic acid solution to the seed particle dispersion subjected to the heat-aging.

A process for producing a charge-reversed aqueous silica sol includes: (a) providing a slurry of an acidic cation-exchange solid in an aqueous liquid; (b) providing a starting aqueous silica sol with an alkaline pH and including a monovalent cation(s); (c) contacting the slurry with the starting sol; (d) separating the acidic cation-exchange solid from the mixture (c) to leave a decationised aqueous silica sol with an acidic pH and a reduced monovalent cation(s) content compared to the starting sol; and (e) contacting the decationised sol with a compound(s) including a modifying element(s) that can adopt a +3 or +4 oxidation state to produce a charge-reversed aqueous silica sol whose silica particles include the modifying element(s) on their surface. The S-value of the starting sol is from about 10 to about 50%, and the surface area of colloidal silica particles in the starting sol is at least about 500 m.sup.2 g.sup.1.