A modified boron nitride nanotube (BNNT) comprising pendant hydroxyl (OH) and amino (NH.sub.2) functional groups covalently bonded to a surface of the BNNT. Aqueous and organic solutions of these modified BNNTs are disclosed, along with methods of producing the same. The modified BNNTs and their solutions can be used to coat substrates and to make nanocomposites.

The present invention comprises the steps of contacting a boron nitride nanotube and a stabilizer in a solvent, and removing a portion of the solvent to obtain a liquid crystal composition including a liquid crystal in which at least a portion of the stabilizer is adsorbed on the surface of the boron nitride nanotube.

The present invention comprises the steps of contacting a boron nitride nanotube and a stabilizer in a solvent, and removing a portion of the solvent to obtain a liquid crystal composition including a liquid crystal in which at least a portion of the stabilizer is adsorbed on the surface of the boron nitride nanotube.

A method for producing an aggregated boron nitride particle, containing: a nitriding step of nitriding a particle containing boron carbide to obtain a particle containing boron carbonitride; and a decarburizing step of decarburizing the particle containing boron carbonitride to obtain an aggregated boron nitride particle, wherein, in the nitriding step, nitriding is performed so that boron carbide remains inside the particle containing boron carbonitride, and wherein, in the decarburizing step, the boron carbide remaining inside the particle containing boron carbonitride is removed.

A method for producing an aggregated boron nitride particle, containing: a nitriding step of nitriding a particle containing boron carbide to obtain a particle containing boron carbonitride; and a decarburizing step of decarburizing the particle containing boron carbonitride to obtain an aggregated boron nitride particle, wherein, in the nitriding step, nitriding is performed so that boron carbide remains inside the particle containing boron carbonitride, and wherein, in the decarburizing step, the boron carbide remaining inside the particle containing boron carbonitride is removed.

Described herein are methods for continuous production of an exfoliated two-dimensional (2D) material comprising passing a 2D material mixture through a convergent-divergent nozzle, the 2D material mixture comprising a 2D layered material and a compressible fluid. The method of the present disclosure employs physical compression and expansion of a flow of high-pressure gases, leaving the 2D layered material largely defect free to produce an exfoliated 2D layered in a simple, continuous, and environmentally friendly manner.

A fabrication method of a hexagonal boron nitride (h-BN)-based thermally-conductive composite film includes the following steps: S1. attaching an adhesive layer to an h-BN film carried on a carrier film, and separating the h-BN film from the carrier film to obtain a film in which an adhesive layer side is defined as a side A and an h-BN film side is defined as a side B; S2. attaching an adhesive layer to the side B of the film obtained in S1; S3. pasting a high-power graphite film to the side B of a film obtained in S2; S4. attaching an adhesive layer to the side B of a film obtained in S3; and S5. shaping a film obtained in S4 according to a required size. The present fabrication method is conducive to improving the production efficiency or yield rate of a thermally-conductive film product and the product quality.

A cubic boron nitride particle population having highly-etched surfaces and a high toughness index is produced by blending a reactive metal powder with a plurality of cubic boron nitride particles to form a blended mixture. The blended mixture is compressed to form a compressed mixture. The compressed mixture is subjected to a temperature and a pressure, where the temperature is controlled to cause etching of the plurality of cubic boron nitride particles by reaction of cubic boron nitride with the reactive metal powder, thereby forming a plurality of etched cubic boron nitride particles. Also, the temperature and pressure are controlled to cause boron nitride to remain in a cubic boron nitride phase. Afterwards, the plurality of etched cubic boron nitride particles is recovered from the compressed mixture to form the particle population. Preferably, the particle population contains no hexagonal boron nitride.

An insulating filler composed of a mixed powder in which a hydrophobic fumed oxide powder having an average primary particle size D.sub.1, which is smaller than an average primary particle size D.sub.2, is adhered to the surface of a magnesium oxide powder and/or a nitride-based inorganic powder having the average primary particle size D.sub.2, wherein: the ratio D.sub.1/D.sub.2 of the average primary particle size D.sub.1 to the average primary particle size D.sub.2 is 6×10.sup.−5 to 3×10.sup.−3; the volume resistivity of the mixed powder is 1×10.sup.11 Ω.Math.m or more; and the content ratio of the hydrophobic fumed oxide powder in the mixed powder is 5-30 mass %. Also provided is an insulating material in which the above-mentioned insulating filler is contained in a resin molded body.

Disclosed herein are processes for purifying as-synthesized boron nitride nanotube (BNNT) material to remove impurities of boron, amorphous boron nitride (a-BN), hexagonal boron nitride (h-BN) nanocages, h-BN nanosheets, and carbon-containing compounds. The processes include heating the BNNT materials at different temperatures in the presence of inert gas and a hydrogen feedstock or in the presence of oxygen.