466 results about "Titanium dioxide nanoparticles" patented technology

Nanoparticulate titanium dioxide coating produced by educing flocculates of titanium dioxide nanoparticles from a titanyl sulfate solution and dispersing the nanoparticles in a polar sol-forming medium to make a sol suitable as a coating usable to impart photocatalytic activity, U.V. screening properties, and fire retardency to particles and to surfaces. The photocatalytic material and activity is preferably localized in dispersed concentrated nanoparticles, spots or islands both to save costs and leverage anti-microbial effects.

A photoelectrochemical assay apparatus for determining chemical oxygen demand (COD) of a water sample which consists of a) a measuring cell for holding a sample to be analysed b) a titanium dioxide nanoparticle photoelectric working electrode and a counter electrode disposed in said cell, c) a UV light source adapted to illuminate the photoelectric working electrode d) control means to control the illumination of the working electrode e) potential measuring means to measure the electrical potential at the working and counter electrodes f) analysis means to derive a measure of oxygen demand from the measurements made by the potential measuring means. The method of determining chemical oxygen demand of a water sample, comprises the steps of a) applying a constant potential bias to a photoelectrochemical cell, containing a supporting electrolyte solution; b) illuminating the working electrode with a UV light source and recording the background photocurrent produced at the working electrode from the supporting electrolyte solution; c) adding a water sample, to be analysed, to the photoelectrochemical cell; d) illuminating the working electrode with a UV light source and recording the total photocurrent produced; e) determining the chemical oxygen demand of the water sample according to the type of degradation conditions employed. The determination may be under exhaustive degradation conditions, in which all organics present in the water sample are oxidised or under non-exhaustive degradation conditions, in which the organics present in the water sample are partially oxidised.

The invention relates to an improved method for producing silica aerogel in pure and flexible sheet form having effective suppression of radiative heat transport at high temperatures and increased thermal insulation property. The suppression of radiative heat transport was achieved by in-situ production of titanium dioxide nanoparticles in very minor concentrations during gelation of silica precursor, with nanoporous surface area more than 300 m<2> / g and acts as an infra red reflecting agent. When aerogel is subjected to heat during hot object insulation, it automatically turns into infra redreflecting material. Said silica aerogel can be incorporated into the inorganic fibre mat matrix individually or into two or more layers with organic sponge sheet placed in between and stitched together to form a sandwich sheet to form highly insulating flexible sheet.

The invention is directed to a method for reducing the chemical activity and photo activity of titanium dioxide nanoparticles comprising adding a densifying agent, such as citric acid, to an aqueous slurry of the titanium dioxide nanoparticles; treating the aqueous slurry with a source of alumina, such as a solution of sodium aluminate, to form alumina-treated titanium dioxide nanoparticles. In one embodiment the particles are treated with a source of silica, such as a solution of sodium silicate. The nanoparticles of this invention can also be treated with a source of silica and a source of alumina. The treated nanoparticles can be silanized. The titanium dioxide nanoparticles described herein are useful in cosmetic, coating and thermoplastic compositions.

A nanocomposite particle, its use as a catalyst, and a method of making it are disclosed. The nanocomposite particle comprises titanium dioxide nanoparticles, metal oxide nanoparticles, and a surface stabilizer. The metal oxide nanoparticles are formed hydrothermally in the presence of the titanium dioxide nanoparticles. The nanocomposite particle is an effective catalyst support, particularly for DeNOx catalyst applications.

The disclosure provides a sunscreen formulation comprising a peptide-based metal oxide sunscreen agent, such as titanium dioxide nanoparticles, and a fluid vehicle.

Solar-reflective roofing granules having improved solar heat-resistance are formed by coating colored mineral particles with a coating composition including titanium dioxide nanoparticles.

The disclosure is directed to a method for reducing the chemical activity and photo activity of titanium dioxide nanoparticles comprising adding an amorphous alumina-stabilizing agent, specifically an anion, such as citric acid, to an aqueous slurry of the titanium dioxide nanoparticles; treating the aqueous slurry with a source of alumina, such as a solution of sodium aluminate, to form alumina-treated titanium dioxide nanoparticles; recovering the alumina-treated inorganic nanoparticles, wherein the nanoparticles have a particle size of about 50 to about 300 nm; and milling the nanoparticles to form nanoparticles having a particle size about 15% smaller than silica-treated inorganic nanoparticles milled under similar conditions. The titanium dioxide nanoparticles described herein are useful in cosmetic, coating and thermoplastic compositions.