Provided is a process and an apparatus for purifying boron nitride nanotube (BNNT) materials. The process involves the use of a halogen gas to remove halogen-reactive impurities from boron nitride nanotube (BNNT) materials in a single step with minimal interactions to produce structurally pristine BNNT. Gaseous byproducts are produced that 5 can be removed without the need for solution phase treatments. Yield efficiencies and purity of recovered BNNT are high compared to the other known methods of purification for BNNT material.

To provide a composition for a three-dimensional integrated circuit capable of forming a filling interlayer excellent in thermal conductivity also in a thickness direction, using agglomerated boron nitride particles excellent in the isotropy of thermal conductivity, disintegration resistance and kneading property with a resin. A composition for a three-dimensional integrated circuit, comprising agglomerated boron nitride particles which have a specific surface area of at least 10 m.sup.2/g, the surface of which is constituted by boron nitride primary particles having an average particle size of at least 0.05 m and at most 1 m, and which are spherical, and a resin (A) having a melt viscosity at 120 C. of at most 100 Pa.Math.s.

A method of purifying ammonia borane is provided in which crude ammonia borane is dissolved in an organic solvent, such as an ether, and mixed with a basic aqueous solution to form a two-phase system. The pH of the aqueous solution and the temperature are adjusted to increase the solubility of the impurities and decrease the solubility of the ammonia borane in the basic aqueous solution, without causing decomposition of the ammonia borane. The impurities are separated from the crude ammonia borane solution, the mixture is phase-separated and the dissolved ammonia borane is isolated from the organic solvent fraction. High purity ammonia borane is obtained.

Described herein are apparatus, systems, and methods for the continuous production of BNNT fibers, BNNT strands and BNNT initial yarns having few defects and good alignment. BNNTs may be formed by thermally exciting a boron feedstock in a chamber in the presence of pressurized nitrogen. BNNTs are encouraged to self-assemble into aligned BNNT fibers in a growth zone, and form BNNT strands and BNNT initial yarns, through various combinations of nitrogen gas flow direction and velocities, heat source distribution, temperature gradients, and chamber geometries.

A method for synthesizing ammonia borane includes (a) preparing a reaction mixture in one or more solvents, the reaction mixture containing sodium borohydride, at least one ammonium salt, and ammonia; and (b) incubating the reaction mixture at temperatures between about 0 C. to about room temperature in an ambient air environment under conditions sufficient to form ammonia borane. Methods for synthesizing ethylenediamine bisborane, and methods for dehydrogenation of ethylenediamine bisborane are also described.

Flash Joule heating (FJH) for production of one-dimensional (1D) carbon and/or boron nitride nanomaterials, and 1D materials integrated with 0D, 1D, 2D, and 3D nanomaterials, composites, nanostructures, networks, and mixtures thereof. Such materials produced by FJH include 1D carbon and hybrid nanomaterials, boron nitride nanotubes (BNNTs), turbostratic boron-carbon-nitrogen (BCN), doped (substituted) graphene, and heteroatom doped (substituted) re-flashed graphene.

A reactor for catalytic chemical vapor deposition of nanotubes includes a reaction chamber configured to be placed under vacuum and at least one tube situated in the reaction chamber. The tube has a first closed end and a second open end. The reactor also includes at least one boat situated in the tube, at least one substrate situated on each of the at least one boats, and nanotube source material in each boat of the at least one boats. A method for catalytic chemical vapor deposition of boron nitride nanotubes is also disclosed.