Abstract: Methods and apparatuses for making nanomaterials are disclosed. The methods involve passing one or more source materials through a high pressure and high temperature chamber with an open throat, and then allowing the reactants to expand into a lower pressure, lower temperature zone. The source material is non-stoichiometric and fuel-rich so that excess un-combusted primary source material can form the nanomaterials. In some cases, the apparatus may be in the form of a modified rocket engine. The methods may be used to make various materials including: carbon nanotubes, boron nitride nanomaterials, titanium dioxide, and any materials that are currently produced by flame synthesis, including but not limited to electrocatalysts. The methods may also be used to make nanomaterials outside the Earth's atmosphere. The methods can include making, coating, or repairing structures in space, such as antennae.

Abstract: Methods and apparatuses for making nanomaterials are disclosed. The methods involve passing one or more source materials through a high pressure and high temperature chamber with an open throat, and then allowing the reactants to expand into a lower pressure, lower temperature zone. The source material is non-stoichiometric and fuel-rich so that excess un-combusted primary source material can form the nanomaterials. In some cases, the apparatus may be in the form of a modified rocket engine. The methods may be used to make various materials including: carbon nanotubes, boron nitride nanomaterials, titanium dioxide, and any materials that are currently produced by flame synthesis, including but not limited to electrocatalysts. The methods may also be used to make nanomaterials outside the Earth's atmosphere. The methods can include making, coating, or repairing structures in space, such as antennae.

Abstract: A method for making nanomaterials includes introducing into a catalyzed reactor vessel: a carrier gas at a first carrier gas feed rate; at least one carbon-based reactant at a first reactant feed rate; and optionally, at least one additive at a first additive feed rate. The reactor vessel is heated to a first temperature of at least 150° C., so that a portion of the carbon-based reactant within the reactor vessel reacts to form a plurality of nanomaterials. An exhaust gas is removed from the reactor and periodically sampled by exposing a paper web to the gas so that a sample of the nanomaterials from the gas are deposited on a region of the paper web for analysis. Based on this analysis, at least one reaction parameter selected from the group consisting of the first carrier gas feed rate, the first reactant feed rate, and first temperature may be adjusted.

Abstract: A carbon nanotube triode apparatus includes a plurality of Horizontally Aligned Single Wall Carbon Nano Tubes (HA-SWCNT disposed on an electrically insulating thermally conductive substrate. A first contact is disposed on the substrate and electrically coupled to a first end of the HA-SWCNT. A second contact is disposed on the substrate and separated from a second end of the HA-SWCNT by a gap. A gate terminal is coincident with a plane of the substrate.

Abstract: A carbon nanotube triode apparatus includes a plurality of Horizontally Aligned Single Wall Carbon Nano Tubes (HA-SWCNT) disposed on an electrically insulating thermally conductive substrate. A first contact is disposed on the substrate and electrically coupled to a first end of the HA-SWCNT. A second contact is disposed on the substrate and separated from a second end of the HA-SWCNT by a gap. A gate terminal is coincident with a plane of the substrate.

Abstract: Methods for enabling or enhancing growth of carbon nanotubes on unconventional substrates. The method includes selecting an inactive substrate, which has surface properties that are not favorable to carbon nanotube growth. A surface of the inactive substrate is treated so as to increase a porosity of the same. CNTs are then grown on the surface having the increased porosity.

Abstract: Improved field emission cathodes comprise a fiber of highly aligned and densely packed single-wall carbon nanotubes, double-wall carbon nanotubes, multi-wall carbon nanotubes, grapheme nanoribbons, carbon nanofibers, and/or carbon planar nanostructures. The fiber cathodes provide superior current carrying capacity without degradation or adverse effects under high field strength testing. The fibers also can be configured as multi-fiber field emission cathodes, and the use of low work function coatings and different tip configurations further improves their performance.

Abstract: The method of the present invention utilizes high pressure, near-supercritical CO2 within a pressure vessel to process filamentary nanocarbon to debulk, disperse, purify, surface treat, pre-impregnate, and micronize the carbon nanofibers. In accordance with the invention, near-supercritical CO2 is utilized within a pressure vessel to effect the desired process upon filamentary nanocarbon. For example, a quantity of filamentary nanocarbon can be effectively debulked, de-agglomerated and disentangled by agitating the mixture within the pressure vessel. When the CO2 is released from the pressure vessel, the filamentary nanocarbon exhibits a dramatic reduction in volume. Other nanofiber processes can be performed such as surface treating and pre-impregnation by introduction of the desirable species into the near-supercritical CO2 prior to processing. Purification processing can additionally be performed by introducing a co-solvent into the near-supercritical CO2.

Abstract: Metal-matrix composites with combinations of physical and mechanical properties desirable for specific applications can be obtained by varying and controlling selected parameters in the material formation processes, particularly by increasing the microstructural homogeneity of the composite, while maintaining a constant mixture ratio or volume fraction. In one embodiment of the invention, a CuSiC composite having increased thermal conductivity is obtained by closely controlling the size of the SiC particles. In another embodiment of the invention, AlSiC composites which exhibit increased ultimate tensile and yield strengths are made by closely controlling the size of SiC and Al particles.

Abstract: Metal-matrix composites with combinations of physical and mechanical properties desirable for specific applications can be obtained by varying and controlling selected parameters in the material formation processes, particularly by increasing the microstructural homogeneity of the composite, while maintaining a constant mixture ratio or volume fraction. In one embodiment of the invention, a CuSiC composite having increased thermal conductivity is obtained by closely controlling the size of the SiC particles. In another embodiment of the invention, AlSiC composites which exhibit increased ultimate tensile and yield strengths are made by closely controlling the size of SiC and Al particles.

Abstract: Novel processes for fabricating metal matrix composites consisting of discontinuous reinforcing particles in a metal matrix are described. In one aspect, reinforcing particles are coated with a metal matrix material by means of chemical vapor deposition using a volatile metal-containing compound, followed by consolidation of the metal-coated particles. In another aspect, reinforcing particles are coated with a metal matrix material by means of electrochemical deposition of a metal, followed by consolidation of the metal-coated particles. In yet another aspect, reinforcing particles coated with a metal matrix material by one of the aforesaid methods are blended with metal or alloy particles not containing such reinforcement, then consolidated.

Abstract: A method for controlling the interface in a titanium matrix composite between the titanium matrix material and a silicon carbide reinforcing filament or fiber which comprises treating such filament or fiber with a phosphorus-containing compound, and thereafter incorporating the treated fiber into a titanium matrix composite. The quantity of phosphorus remaining on the fiber, following treatment, can be miniscule, so long as at least a trace amount of phosphorus remains on the fiber.

Abstract: A method for controlling the interface in a composite between the matrix material and reinforcing filaments or fibers in a composite structure which comprises the application of a patterned coating or combination of coatings on the reinforcing filaments or fibers to vary the bond between the reinforcement and the matrix. Proportioning of weak- and strong-bonded areas, their respective strengths, and design of bonding patterns can be tailored to the materials requirements of the composite.This method can be employed to prepare metal, ceramic and polymer matrix composites.

Abstract: Graphite or carbon particles with a graphitic skin are intercalated with a compound including an oxidized form of a metal and then reduced in a hydrogen atmosphere. This process reduces the driving force for the galvanic reaction between the particles and active metals in aqueous environments. The particles may be present as a reinforcement for a metal matrix (e.g., graphite/aluminum metal matrix composites) or as a reinforcement for a non-metallic material (e.g., graphite/polyimide, graphite/polyester or graphite/cyanate composites). In the latter case, the composite is adjacent to a metal in a structure.By way of example, the graphite or carbon particle may be a fiber, the metal subject to attack may be aluminum or magnesium, and the intercalation compound may be NiCl.sub.2.

Abstract: Filamentous substrates are coated with diamond by a chemical vapor deposin process. The substrate may then be etched away to form a diamond filament. In a preferred embodiment, the substrate is copper-coated graphite. The copper initially passivates the graphite, permitting diamond nucleation thereon. As deposition continues, the copper-coated graphite is etched away by the active hydrogen used in the deposition process. As a result a substrateless diamond tubule is formed. Diamond-coated and diamond filaments are useful as reinforcement materials for composites, as filtration media in chemical and purification processes, in biomedical applications as probes and medicinal dispensers, and in such esoteric areas as chaff media for jamming RF frequencies.