A process for producing a particulate TiO.sub.2 includes supplementing metatitanic acid with an alkali compound in a quantity of 1200 ppm to 2400 ppm of alkali, with a phosphorus compound in a quantity of 0.1 wt.-% to 0.3 wt.-% by weight of P, expressed as phosphorus, and with an aluminum compound in a quantity of 1 ppm to 1000 ppm of Al, expressed as Al, to obtain a mixture. The quantity of the alkali compound, of the phosphorus compound, and of the aluminum compound are with respect to the TiO.sub.2 content. The mixture is calcined at a constant temperature of 940° C. to 1020° C. until a numerical fraction X.sub.50 of TiO.sub.2 has a primary crystallite size of at least 200 nm, to obtain a calcined mixture. The calcined mixture is cooled to obtain a cooled calcined mixture. The cooled calcined mixture is grinded to obtain the particulate TiO.sub.2.

A method for preparing two-dimensional (2D) ordered mesoporous nanosheets by inorganic salt interface-induced assembly includes the following steps: carrying out, by using a soluble inorganic salt as a substrate and an amphiphilic block copolymer as a template, uniform mass diffusion of a target precursor solution at an inorganic salt crystal interface through vacuum filtration or low-speed centrifugation; forming a single-layer ordered mesoporous structure by using the solvent evaporation-induced co-assembly (EICA) technology; and promoting, through gradient temperature-controlled Ostwald ripening, the evaporation and induced formation of an organic solvent, and removing the template in N2 to obtain a 2D single-layer ordered mesoporous nanosheet material. The assembled nanosheet material has a large pore size, regular spherical pores and orderly arrangement. By changing the type of the precursor, a variety of mesoporous metal oxides, metal elements, inorganic non-metal nanosheets are synthesized.

A method for preparing two-dimensional (2D) ordered mesoporous nanosheets by inorganic salt interface-induced assembly includes the following steps: carrying out, by using a soluble inorganic salt as a substrate and an amphiphilic block copolymer as a template, uniform mass diffusion of a target precursor solution at an inorganic salt crystal interface through vacuum filtration or low-speed centrifugation; forming a single-layer ordered mesoporous structure by using the solvent evaporation-induced co-assembly (EICA) technology; and promoting, through gradient temperature-controlled Ostwald ripening, the evaporation and induced formation of an organic solvent, and removing the template in N2 to obtain a 2D single-layer ordered mesoporous nanosheet material. The assembled nanosheet material has a large pore size, regular spherical pores and orderly arrangement. By changing the type of the precursor, a variety of mesoporous metal oxides, metal elements, inorganic non-metal nanosheets are synthesized.

A process for the preparation of an antimicrobial coating solution is described. The process comprises the steps of: (i) mixing a chelating agent with titanium alkoxide and fluoroacetic acid; and (ii) adding an aqueous solution to the mixture from step (i). The antimicrobial coating described is visible light activated. The coating is applied to surfaces and then heat treated to form a transparent layer on the surface. This is particularly advantageous where the surface is glass.

A process for the preparation of an antimicrobial coating solution is described. The process comprises the steps of: (i) mixing a chelating agent with titanium alkoxide and fluoroacetic acid; and (ii) adding an aqueous solution to the mixture from step (i). The antimicrobial coating described is visible light activated. The coating is applied to surfaces and then heat treated to form a transparent layer on the surface. This is particularly advantageous where the surface is glass.

Disclosed is a method for producing deposition particles or intermediate particles, characterized in that the method comprises: forming a solution comprising a solvent and one or more deposit sources, aerosolizing the formed solution to produce an aerosol of precursor particles comprising the deposit source, conditioning the precursor particles to produce deposition particles or intermediate particles from the deposit source and collecting said particles. The particles may be collected as a deposit or precursor deposit on a substrate. The particles may include a matrix material and a dopant. The conditioning may be quenched to produce a desired substructure. The matrix material may be essentially optically clear. The substrate may comprise an optical fiber or an optical fiber preform or mandrel.

Disclosed is a method for producing deposition particles or intermediate particles, characterized in that the method comprises: forming a solution comprising a solvent and one or more deposit sources, aerosolizing the formed solution to produce an aerosol of precursor particles comprising the deposit source, conditioning the precursor particles to produce deposition particles or intermediate particles from the deposit source and collecting said particles. The particles may be collected as a deposit or precursor deposit on a substrate. The particles may include a matrix material and a dopant. The conditioning may be quenched to produce a desired substructure. The matrix material may be essentially optically clear. The substrate may comprise an optical fiber or an optical fiber preform or mandrel.

Hollow particles containing monocrystalline titanium oxide and silica, and having a titanium oxide content of 86.0-99.5 mol % and a silica content of 0.5-14.0 mol %; and a method of producing the particles. A white ink containing the hollow particles as a coloring agent; the use of the white ink in inkjet recording; and a method for inkjet recording using the white ink.

According to one inventive concept, a method for forming an aerogel includes forming a SiO.sub.2 gel, forming a mixture of the SiO.sub.2 gel and a TiCl.sub.4-derived precursor sol, wherein the TiCl.sub.4 sol is comprised of TiCl.sub.4 and a solvent, forming a SiO.sub.2/TiO.sub.2 wet gel, drying the SiO.sub.2/TiO.sub.2 wet gel, and heating the dried SiO.sub.2/TiO.sub.2 gel.

According to one inventive concept, a method for forming an aerogel includes forming a SiO.sub.2 gel, forming a mixture of the SiO.sub.2 gel and a TiCl.sub.4-derived precursor sol, wherein the TiCl.sub.4 sol is comprised of TiCl.sub.4 and a solvent, forming a SiO.sub.2/TiO.sub.2 wet gel, drying the SiO.sub.2/TiO.sub.2 wet gel, and heating the dried SiO.sub.2/TiO.sub.2 gel.