摘要:
Nanotube filaments comprising carbon, boron and nitrogen of the general formula BxCyNz, having high-aspect ratio and high-crystallinity produced by a pressurized vapor/condenser method and a process of production. The process comprises thermally exciting a boron-containing target in a chamber containing a carbon source and nitrogen at a pressure which is elevated above atmospheric pressure.
摘要:
Nanotube filaments comprising carbon, boron and nitrogen of the general formula BxCyNz, having high-aspect ratio and high-crystallinity produced by a pressurized vapor/condenser method and a process of production. The process comprises thermally exciting a boron-containing target in a chamber containing a carbon source and nitrogen at a pressure which is elevated above atmospheric pressure.
摘要:
Effective radiation shielding is required to protect crew and equipment in various fields including aerospace, defense, medicine and power generation. Light elements and in particular hydrogen are most effective at shielding against high-energy particles including galactic cosmic rays, solar energetic particles and fast neutrons. However, pure hydrogen is highly flammable, has a low neutron absorption cross-section, and cannot be made into structural components. Nanocomposites containing the light elements Boron, Nitrogen, Carbon and Hydrogen as well dispersed boron nano-particles, boron nitride nanotubes (BNNTs) and boron nitride nano-platelets, in a matrix, provide effective radiation shielding materials in various functional forms. Boron and nitrogen have large neutron absorption cross-sections and wide absorption spectra. The incorporation of boron and nitrogen containing nanomaterials into hydrogen containing matrices provides composites that can effectively shield against neutrons and a wide range of radiation species of all energies without fragmentation and the generation of harmful secondary particles.
摘要:
Formation of a boron nitride nanotube nanocomposite film by combining a boron nitride nanotube solution with a matrix such as a polymer or a ceramic to form a boron nitride nanotube/polyimide mixture and synthesizing a boron nitride nanotube/polyimide nanocomposite film as an electroactive layer.
摘要:
Electroactive actuation characteristics of novel BNNT based materials are described. Several series of BNNT based electroactive materials including BNNT/polyimide composites and BNNT films are prepared. The BNNT based electroactive materials show high piezoelectric coefficients, d13, about 14.80 pm/V as well as high electrostrictive coefficients, M13, 3.21×10−16 pm2N2. The BNNT based electroactive materials will be used for novel electromechanical energy conversion devices.
摘要:
Boron nitride nanotubes are prepared by a process which includes: (a) creating a source of boron vapor; (b) mixing the boron vapor with nitrogen gas so that a mixture of boron vapor and nitrogen gas is present at a nucleation site, which is a surface, the nitrogen gas being provided at a pressure elevated above atmospheric, e.g., from greater than about 2 atmospheres up to about 250 atmospheres; and (c) harvesting boron nitride nanotubes, which are formed at the nucleation site.
摘要:
Boron nitride nanotubes are prepared by a process which includes: (a) creating a source of boron vapor; (b) mixing the boron vapor with nitrogen gas so that a mixture of boron vapor and nitrogen gas is present at a nucleation site, which is a surface, the nitrogen gas being provided at a pressure elevated above atmospheric, e.g., from greater than about 2 atmospheres up to about 250 atmospheres; and (c) harvesting boron nitride nanotubes, which are formed at the nucleation site.
摘要:
An improved method for the production of single walled carbon nanotubes that utilizes an RF-induction heated side-pumped synthesis chamber for the production of such. Such a method, while capable of producing large volumes of carbon nanotubes, concurrently permits the use of a simplified apparatus that allows for greatly reduced heat up and cool down times and flexible flowpaths that can be readily modified for production efficiency optimization. The method of the present invention utilizes a free electron laser operating at high average and peak fluence to illuminate a rotating and translating graphite/catalyst target to obtain high yields of SWNTs without the use of a vacuum chamber.
摘要:
Carbon nanotubes (CNTs) are mixed in an aqueous buffer solution that includes a buffer material having a molecular structure defined by a first end, a second end, and a middle disposed between the first and second ends. The first end is a cyclic ring with nitrogen and oxygen heteroatomes, the middle is a hydrophobic alkyl chain, and the second end is a charged group. The resulting solution includes the CNTs dispersed therein. Metal-core ferritins are then mixed into the resulting solution where at least a portion of the ferritins are coupled to the CNTs.
摘要:
Carbon nanotubes (CNTs) are dispersed in an aqueous buffer solution consisting of at least 50 weight percent water and a remainder weight percent that includes a buffer material. The buffer material has a molecular structure defined by a first end, a second end, and a middle disposed between the first and second ends. The first end is a cyclic ring with nitrogen and oxygen heteroatomes, the middle is a hydrophobic alkyl chain, and the second end is a charged group.