Provided are a tabular alumina particle and a method for manufacturing it, wherein the particle has a major axis of 30 μm or more, a thickness of 3 μm or more, and an aspect ratio of 2 to 50 and contains molybdenum; and the method includes the steps of mixing an aluminum compound of 10% by mass or more in a form of Al.sub.2O.sub.3, a molybdenum compound of 20% by mass or more in a form of MoO.sub.3, a potassium compound of 1% by mass or more in a form of K.sub.2O, and silicon or a silicon compound of less than 1% by mass in a form of SiO.sub.2, where total amount of raw materials is assumed to be 100% by mass in forms of oxides, so as to produce a mixture and firing the resulting mixture.

Systems, devices, and techniques for manufacturing a crystalline material (e.g., large crystal material) through the solid state conversion of a polycrystalline material are described. A device may be configured to concurrently heat a volume of ribbon, such as an alumina ribbon, using multiple heat sources. For example, a first heat source may heat a first volume of the ribbon and a second heat source may concurrently heat a second volume, for example, within the first volume, where the ribbon may comprise polycrystalline material. The concurrent heating may drive grain growth in the polycrystalline material in at least the second volume, which may convert the polycrystalline material to crystalline material having one or more grains that are larger than one or more grains of the polycrystalline material. The processed ribbon may include a large crystal material or a single crystal material.

A nano platelet gibbsite treated with compound of formula (OR.sup.a).sub.3Si—R or of formula R.sup.c—COOH wherein R.sup.a equal to or different from each other is a C.sub.1-C.sub.10 alkyl radical; R.sup.b is a C.sub.5-C.sub.30 hydrocarbon radical and R.sup.c is a C.sub.5-C.sub.30 hydrocarbon radical is used as a catalyst support.

A method of producing new hydrophobic aluminas by i) providing a slurry comprising an alumina compound, the slurry having a pH of above 5.5; ii) mixing an organic composition comprising carboxylic acids with long hydrocarbon chains with the slurry to form an acid modified slurry; iii) hydrothermally conditioning the acid modified slurry to form a hydrothermally aged slurry; and iv) drying the hydrothermally aged slurry. The new hydrophobic aluminas have surface modified structures distinguished by a low humidity content and very small nanoparticles. These new hydrophobic aluminas can be uniformly dispersed in a substrate, for example polymers.

A method of producing a hydrophobic porous alumina by: i) providing a slurry comprising an alumina compound, the slurry having a pH equal to or greater than 7; ii) adding an organic composition comprising carboxylic acids with alkyl hydrocarbon chains having a carbon length less than 14 to the slurry to form an acidic modified slurry; the acidic modified slurry having a pH of between 3 and less than 7; iii) hydrothermally aging the acidic modified slurry to form a hydrothermally aged slurry; and iv) drying the hydrothermally aged slurry.

A sparsely pillared organic-inorganic hybrid compound is provided. The sparsely pillared organic-inorganic hybrid compound includes: two inorganic material layers, each extending in one direction and facing each other; and an organic material layer disposed between the two inorganic material layers, wherein each of the inorganic material layers has a gibbsite structure in which a divalent metal cation is doped to an octahedral site, and the organic material layer includes a plurality of pillar portions, each of which is chemically bound to each of the two inorganic material layers such that the two inorganic material layers are connected to each other.

Provided is a method of preparing a sparsely pillared organic-inorganic hybrid compound. The method of preparing an organic-inorganic hybrid compound includes: preparing a compound having a gibbsite structure by a method other than a hydrothermal synthesis method, using a trivalent metal cation source, an alkali imparting agent, and a first solvent (S10); and preparing an organic-inorganic hybrid compound by a method other than a hydrothermal synthesis method, using the compound of the gibbsite structure, a divalent metal cation source, dicarboxylic acid, and a second solvent (S20).

Alumina products containing a fine particle size component and a coarse particle size component, and with specific particle size characteristics and irregular and non-spherical particle shapes, are disclosed. These alumina products can be used in polymer formulations to produce composites having high isotropic thermal conductivity.

A treatment method of a sapphire material, said method comprising bombardment of a surface of the sapphire material, said surface facing a medium different from the sapphire material, by a single- and/or multi-charged gas ion beam so as to produce an ion implanted layer in the sapphire material, wherein the ions are selected from ions of the elements from the list consisting of helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), boron (B), carbon (C), nitrogen (N), oxygen (O), fluorine (F), silicon (Si), phosphorus (P) and sulphur (S). Use of said method to obtain a capacitive touch panel having a high transmission in the visible range.

Alumina products containing a fine particle size component and a coarse particle size component, and with specific particle size characteristics and irregular and non-spherical particle shapes, are disclosed. These alumina products can be used in polymer formulations to produce composites having high isotropic thermal conductivity.