Abstract: A tin(IV) oxide dispersion is prepared by peptising metastannic acid with amine peptising agent such as n-butylamine or cyclohexylamine. The dispesion may be a sol or an intermediate convertible to a sol, and may include other components such as metal oxides or their precursors, e.g. one or more of a high surface area alumina and transition metal oxides such as copper(II) oxide and chromium (VI) oxide. The dispersion may be converted to a gel and then to a ceramic, optionally after the sol has been contacted with a substrate, for example to produce a catalyst. Further coatings may be applied to produce a catalyst comprising a mixture of tin(IV) oxide and chromium(VI) oxide on the substrate which may be effective as an oxidation catalyst and useful in the treatment of vehicle exhaust emissions.

Abstract: The present invention relates to the treatment of gel materials to remove water therefrom. The invention provides a process for removing water from a gel material by contacting the gel material with an organic liquid and contacting the organic liquid with a gas such that water is taken up by the gas. The invention, in one embodiment, may be used to dry gel materials while maintaining an open porous network therein.

Abstract: The present invention relates to the preparation of materials and finds application in the preparation of dispersions and gels.The invention provides, in one aspect, a process for the preparation of a dispersion which comprises treating a chemical compound with a quaternary ammonium hydroxide so as to peptize the chemical compound to form a dispersion.The dispersion may be, for example, a suspension or a sol (i.e. a colloidal solution). The chemical compound may be, for example, a hydrous metal oxide (e.g. hydrous stannic oxide).Mixed dispersions may be formed in accordance with the present invention.

Abstract: A nickel oxide electrode is made by impregnating a porous nickel substrate with a dispersion of a nickel compound, converting the compound in situ to nickel hydroxide, and removing reaction products.In order to overcome corrosion problems, facilitate removal of by-products and improve electrode performance, the dispersion is provided in a non-aqueous medium (e.g. as a methanolic solution of NiCl.sub.2.6H.sub.2 O) such that the in situ conversion gives rise to the nickel hydroxide in the form of a gel and to easily removable (e.g. volatile) reaction products. Such a conversion may be carried out by contacting the methanolic solution with an epoxy compound such as propylene oxide.

Abstract: The present invention relates to the preparation of materials and more particularly to the preparation of tin oxide materials.Thus, the present invention provides a process for the preparation of a tin oxide material by a gel precipitation process which includes contacting together a metal stannate, an organic gelling agent comprising a salt of a polycarboxylic acid and an acidic precipitating agent to form a gel precipitate.The gel precipitate may be treated further to provide the tin oxide material.The tin oxide material may be tin oxide as such, or a mixed oxide material containing tin oxide and an oxide of another element.

Abstract: The present invention relates to the treatment of gel materials to remove water therefrom.The invention provides a process for removing water from a gel material by contacting the gel material with a gaseous mixture of an organic compound and a gas. The organic compound, the gas and conditions of contacting are selected such that water is extracted from the gel material and passes into the gaseous mixture.The invention in one embodiment may be used to dry gel materials while maintaining an open porous network therein.

Abstract: A substrate is provided with a refractory oxide coating by contacting the substrate with a dispersion of a solid particulate phase in a liquid phase, subsequently followed by firing to produce the coating, the dispersion comprising at least a first and a second refractory oxide component.In order to produce a coating of controlled purity, e.g. for certain catalytic, electronic or other appications, the first refractory oxide component (e.g. an alumina) is obtained from a purifiable liquid or solid precursor therefor and constitutes part at least of the solid phase, and the second refractory oxide component is either obtained from a purifiable liquid or solid precursor therefor and constitutes part of the solid phase or is a purifiable liquid precursor (e.g. a water-soluble silicone) constituting part at least of the liquid phase.

Abstract: A process is disclosed for the preparation of a complex of an element in solution, said complex including the element and an organic complexing agent, which process comprises treating a gel precipitate containing the element and an organic complexing agent to redisperse the gel precipitate into solution.