A polycrystalline cubic boron nitride comprising 98.5% by volume or more of cubic boron nitride, wherein the cubic boron nitride has a dislocation density of more than 8×10.sup.15/m.sup.2, the polycrystalline cubic boron nitride comprises a plurality of crystal grains, and the plurality of crystal grains have a median diameter d50 of an equivalent circle diameter of 0.1 μm or more and 0.5 μm or less.

A radical anion based functionalization of two-dimensional (2D) layered materials is proposed. The covalent functionalization of the basal plane of 2D materials with charge neutral radicals is typically unstable to reduction, leading to detachment of the functional groups from the basal plane upon reduction. This instability hinders the use of functionalized 2D materials as rechargeable electroactive species, unless the functional groups are bound to the edges of the 2D material. However, to achieve high capacity without the creation of many edges and defects, a stable functionalization of the basal plane in the reduced state is required. This goal can be achieved by radical anion functionalization, whereby the reduced/discharged state of the basal-plane-functionalized 2D material is produced. The product of the radical anion functionalization can be used as the discharged state of a cathode active material, solid electrolyte or part of a polymer composite.

A radical anion based functionalization of two-dimensional (2D) layered materials is proposed. The covalent functionalization of the basal plane of 2D materials with charge neutral radicals is typically unstable to reduction, leading to detachment of the functional groups from the basal plane upon reduction. This instability hinders the use of functionalized 2D materials as rechargeable electroactive species, unless the functional groups are bound to the edges of the 2D material. However, to achieve high capacity without the creation of many edges and defects, a stable functionalization of the basal plane in the reduced state is required. This goal can be achieved by radical anion functionalization, whereby the reduced/discharged state of the basal-plane-functionalized 2D material is produced. The product of the radical anion functionalization can be used as the discharged state of a cathode active material, solid electrolyte or part of a polymer composite.

The boron nitride nanomaterial of the present invention is a boron nitride nanomaterial comprising a boron nitride nanotube and a boron nitride nanosheet, and having a peak top of a Raman spectrum located at 1369 cm.sup.−1 or more.

A group of reductive 2D materials (R2D) with extended reactive vacancies and a method for making the R2D with extended reactive vacancies are provided, especially the example of the reductive boron nitride (RBN). To create defects such as vacancies, boron nitride (BN) powders are milled at cryogenic temperatures. Vacancies are produced by milling, and the vacancies can be used to reduce various metal nanostructures on RBN. Due to the thermal stability of the RBN and the enhanced catalytic performance of metal nanostructures, RBN-metals can be used for different catalysts, including electrochemical catalysts and high temperature catalysts.

Provided is a boron nitride powder including: an agglomerated particle obtained by aggregating flaky primary particles, in which in-plane directions of the primary particles are oriented in a direction parallel to a short-side direction of the agglomerated particle. In addition, provided is a method for producing a boron nitride powder including: a nitriding step of firing a boron carbide powder having an aspect ratio of 1.5 to 10 in a nitrogen pressurized atmosphere to obtain a fired product; and a crystallization step of heating a formulation that contains the fired product and a boron source to produce flaky boron nitride primary particles and obtaining a boron nitride powder containing an agglomerated particle obtained by aggregating the primary particles.

Provided is a boron nitride powder including: an agglomerated particle obtained by aggregating flaky primary particles, in which in-plane directions of the primary particles are oriented in a direction parallel to a short-side direction of the agglomerated particle. In addition, provided is a method for producing a boron nitride powder including: a nitriding step of firing a boron carbide powder having an aspect ratio of 1.5 to 10 in a nitrogen pressurized atmosphere to obtain a fired product; and a crystallization step of heating a formulation that contains the fired product and a boron source to produce flaky boron nitride primary particles and obtaining a boron nitride powder containing an agglomerated particle obtained by aggregating the primary particles.

A first object of the present invention is to provide a surface-modified inorganic nitride having excellent dispersibility. Furthermore, a second object of the present invention is to provide a composition, a thermally conductive material, and a device with a thermally conductive layer which contain the surface-modified inorganic nitride. The surface-modified inorganic nitride of the present invention includes an inorganic nitride, and a specific compound adsorbed onto a surface of the inorganic nitride, and the specific compound has a functional group selected from the group consisting of a boronic acid group, an aldehyde group, an isocyanate group, an isothiocyanate group, a cyanate group, an acyl azide group, a succinimide group, a sulfonyl chloride group, a carboxylic acid chloride group, an onium group, a carbonate group, an aryl halide group, a carbodiimide group, an acid anhydride group, a carboxylic acid group, a phosphonic acid group, a phosphinic acid group, a phosphoric acid group, a phosphoric acid ester group, a sulfonic acid group, a halogenated alkyl group, a nitrile group, a nitro group, an ester group, a carbonyl group, an imidoester group, an alkoxysilyl group, an acrylic group, a methacrylic group, an oxetanyl group, a vinyl group, an alkynyl group, a maleimide group, a thiol group, a hydroxyl group, a halogen atom, and an amino group, and has a fused-ring structure containing two or more rings selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring.

A microstructure comprises a plurality of interconnected units wherein the units are formed of hexagonal boron nitride (h-BN) tubes. The graphene tubes may be formed by photo-initiating the polymerization of a monomer in a pattern of interconnected units to form a polymer microlattice, removing unpolymerized monomer, coating the polymer microlattice with a metal, removing the polymer microlattice to leave a metal microlattice, depositing an h-BN precursor on the metal microlattice, converting the h-BN precursor to h-BN, and removing the metal microlattice.

A method of manufacturing a silica-coated boron nitride particle including a first step of covering the surface of the boron nitride particle with an organic silicone compound having a specific structure and a second step of heating the boron nitride particle covered with the organic silicone compound at a temperature of 500° C. or more and 1000° C. or less, wherein the content of carbon atoms in the silica-coated boron nitride particle is 1000 ppm by mass or less. Also disclosed is a method of manufacturing a heat dissipating resin composition containing the silica-coated boron nitride particle; and silica-coated boron nitride particles.