Durable, porous alumina-carbon nanotube membranes and methods for making them using spark plasma sintering. Methods for removing heavy metals such as cadmium from waste water using alumina-carbon nanotube membranes.

Methods of forming solid carbon products include disposing nanostructure carbon in a container, disposing the container in a press, compressing the nanostructured carbon within the container, and fastening a lid to the container to form a filter. Further processing may include sintering the nanostructured carbon within the container and heating the nanostructured carbon within the container in an inert environment to form bonds between adjacent particles of nanostructured carbon. Other methods may include forming a plurality of compressed nanostructured carbon modules, placing the plurality of compressed nanostructured carbon modules within a container, and placing a lid on the container to form a filter structure. Related structures are also disclosed.

A method of preparing a boron nitride material, such as boron nitride (BN) or boron carbonitride (BCN), is provided. The method may include providing a substrate, and sublimating an amine borane complex onto the substrate to obtain the boron nitride material. The amine borane complex may include, but is not limited to, borazine, amino borane, trimethylamine borane and triethylamine borane. In addition, the temperature at which the sublimating is carried out may be varied to control composition of the boron nitride material formed. In addition, various morphologies can be obtained by using the present method, namely films, nanotubes and porous foam.

Methods of forming solid carbon products include disposing a plurality of nanotubes in a press, and applying heat to the plurality of carbon nanotubes to form the solid carbon product. Further processing may include sintering the solid carbon product to form a plurality of covalently bonded carbon nanotubes. The solid carbon product includes a plurality of voids between the carbon nanotubes having a median minimum dimension of less than about 100 nm. Some methods include compressing a material comprising carbon nanotubes, heating the compressed material in a non-reactive environment to form covalent bonds between adjacent carbon nanotubes to form a sintered solid carbon product, and cooling the sintered solid carbon product to a temperature at which carbon of the carbon nanotubes do not oxidize prior to removing the resulting solid carbon product for further processing, shipping, or use.

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 ceramic composite material comprises a ceramic compound, a plurality of shaping particles dispersed in the ceramic compound, and a plurality void spaces dispersed in the ceramic compound. The plurality of shaping particles are contained within the plurality of void spaces, and each of the plurality of void spaces is a closed cell. The plurality of shaping particles also comprise nanostructures have a length to diameter ratio of less than or equal to 10 to 1 and a length of less than or equal to 500 nanometers.

A composite article is comprised of coal dust, as defined herein, and a polymer derived ceramic material that is pyrolyzed in a substantially non-oxidizing atmosphere. For example, the composite article may be made of a mixture of the coal dust and polymer derived ceramic, from particles formed of a mixture of coal dust and polymer derived ceramic or from complex particle composites comprising a plurality of particles formed of a mixture of coal dust and polymer derived ceramic.

A method of treating a carbon/carbon composite is provided. The method may include infiltrating a carbonized fibrous structure with hydrocarbon gas to form a densified fibrous structure. The method may include treating the densified fibrous structure with heat at a first temperature range from about 1600 to about 2400 C. to form a heat treated densified fibrous structure. The method may include infiltrating the heat treated densified fibrous structure with silicon to form a silicon carbide infiltrated fibrous structure.

A preparation method of an alumina-carbon nano tube composite powder material includes the steps of using an organometallic precursor as a raw material, using metal nanoparticles formed on the surface of the alumina powder as a catalyst, and simultaneously feeding a carbonaceous gas such as methane and acetylene, so as to grow a carbon nano tube in situ, and obtain an alumina-metal nanoparticle-carbon nano tube composite powder material through a chemical vapor deposition method under a temperature condition of 400 to 800 C. Through changing various parameters such as the weight of the organic raw material, the flow or constituent of reactant gases and reaction temperature, the decomposition of the organic raw material and the generation of the metal nanoparticles and the carbon nano tube are adjusted, and the size and the microstructure of the powder are controlled.

A ceramic composite material comprises a ceramic compound, a plurality of shaping particles dispersed in the ceramic compound, and a plurality void spaces dispersed in the ceramic compound. The plurality of shaping particles are contained within the plurality of void spaces, and each of the plurality of void spaces is a closed cell. The plurality of shaping particles also comprise nanostructures have a length to diameter ratio of less than or equal to 10 to 1 and a length of less than or equal to 500 nanometers.