Methods of producing silicon carbide, and other metal carbide materials. The method comprises reacting a carbon material (e.g., fibers, or nanoparticles, such as powder, platelet, foam, nanofiber, nanorod, nanotube, whisker, graphene (e.g., graphite), fullerene, or hydrocarbon) and a metal or metal oxide source material (e.g., in gaseous form) in a reaction chamber at an elevated temperature ranging up to approximately 2400 C. or more, depending on the particular metal or metal oxide, and the desired metal carbide being produced. A partial pressure of oxygen in the reaction chamber is maintained at less than approximately 1.0110.sup.2 Pascal, and overall pressure is maintained at approximately 1 atm.

A material that facilitates dissipation of heat is provided and includes hexagonal boron nitride and alumina.

Methods for fabricating a ceramic matrix composite are disclosed. A fiber preform may be placed in a mold. An aqueous solution may be added to the fiber preform. The aqueous solution may include water, carbon nanotubes, and a binder. The preform may be frozen. Freezing the preform may cause the water to expand and separate fibers in the fiber preform. The carbon nanotubes may bond to the fibers. The preform may be freeze dried to remove the water. The preform may then be processed according to standard CMC process.

A method of producing, from a continuous or discontinuous (e.g., chopped) carbon fiber, partially to fully converted metal carbide fibers. The method comprises reacting a carbon fiber material with at least one of a metal or metal oxide source material at a temperature greater than a melting temperature of the metal or metal oxide source material (e.g., where practical, at a temperature greater than the vaporization temperature of the metal or metal oxide source material). Additional methods, various forms of carbon fiber, metal carbide fibers, and articles including the metal carbide fibers are also disclosed.

An extrusion method and apparatus are described for producing ceramics, glass, glass-ceramics, or composites suitable for use as proppants. The method includes forming one or more green body materials, extruding the green body materials to form a green body extrudate, separating and shaping the green body extrudate into individual green bodies, and sintering the green bodies to form proppants. The apparatus includes a means for forming an intimate mixture of green body materials, means to produce a green body extrudate, means for separating and shaping the green body extrudate into individual green bodies, and means to sinter the green green bodies to form proppants.

The processes and products described herein optimize transformation of BNNT as-synthesized material into BNNT intermediary materials. Process steps include refining to remove boron particulates, high temperature refining to break bonds between BNNT, h-BN nanocages, h-BN nanosheets and amorphous BN particles, centrifuging and microfluidic separation, and electrophoresis. Resultant BNNT intermediary materials include purified BNNT in solution, BNNT gels, h-BN nanocages, and h-BN nanosheets, gel spun BNNT fibers, hydrophilic defect enhanced BNNT materials, BNNT patterned sheets, and BNNT strands. Applications that will utilize these BNNT precursor feedstock materials include making BNNT based aligned components, thin films, aerogels, thermal conductivity enhancements, structural materials, ceramic, metal, and polymer composites, and removal of PFAS pollutants from water.

This disclosure provides systems, methods, and apparatus related to boron nitride nanomaterials. In one aspect, a method includes generating a directed flow of plasma. A boron-containing species is introduced to the directed flow of the plasma. Boron nitride nanostructures are formed in a chamber. In another aspect, a method includes generating a directed flow of plasma using nitrogen gas. A boron-containing species is introduced to the directed flow of the plasma. The boron-containing species can consist of boron powder, boron nitride powder, and/or boron oxide powder. Boron nitride nanostructures are formed in a chamber, with a pressure in the chamber being about 3 atmospheres or greater.

Methods of growing boron nitride nanotubes and silicon nanowires on carbon substrates formed from carbon fibers. The methods include applying a catalyst solution to the carbon substrate and heating the catalyst coated carbon substrate in a furnace in the presence of chemical vapor deposition reactive species to form the boron nitride nanotubes and silicon nanowires. A mixture of a first vapor deposition precursor formed from boric acid and urea and a second vapor deposition precursor formed from iron nitrate, magnesium nitrate, and D-sorbitol are provided to the furnace to form boron nitride nanotubes. A silicon source including SiH.sub.4 is provided to the furnace at atmospheric pressure to form silicon nanowires.

Composite material units (CMU) of the structure (SE1-ML-LinkerL-Ligand2-SE2), are provided, wherein ML is a Mechanical Ligand, LinkerL is a chemical bond or entity that covalently links ML and Ligand2, Ligand2 is a chemical entity that is covalently linked to the structural entity SE2, or forms a mechanical bond with the structural entity SE2, and SE1 and SE2 are structural entities.

In a first aspect, the present disclosure provides a method for making an inorganic thermoset resin, the method comprising: (a) mixing SiO.sub.2, H.sub.2O and a metallic hydroxide for generating an alkaline aqueous solution with pH from 10 to 14 comprising a metallic silicate, wherein said metallic hydroxide generates a first metallic oxide in the aqueous solution, (b) adding aluminum oxide (Al.sub.2O.sub.3) and silicon oxide (SiO.sub.2) to the alkaline aqueous solution comprising a metallic silicate generated in step (a) and (c) adding halloysite nanotubes (Al.sub.2Si.sub.2O.sub.5(OH).sub.4) to the solution generated in step (b).

The present disclosure further provides an inorganic thermoset resin obtainable by the method as defined in the first aspect of the disclosure.