摘要:
Methods for sensing and building sensors provide for adding nanotubes to a sensor to improve characteristics such as the Q-factor associated with the sensor. Mass loading and damping characteristics of micromachined quartz crystal resonators on which a thin film of debundled single-walled carbon nanotube (SWNT) has been deposited are disclosed. An absolute mass sensitivity of ˜100 fg was experimentally measured by monitoring the continuous desorption of gases from SWNT surfaces in a vacuum ambient.
摘要:
Methods for sensing and building sensors provide for adding nanotubes to a sensor to improve characteristics such as the Q-factor associated with the sensor. Mass loading and damping characteristics of micromachined quartz crystal resonators on which a thin film of debundled single-walled carbon nanotube (SWNT) has been deposited are disclosed. An absolute mass sensitivity of ˜100 fg was experimentally measured by monitoring the continuous desorption of gases from SWNT surfaces in a vacuum ambient.
摘要:
Single walled carbon nanotubes are produced in a novel apparatus by the laser-induced ablation of moving carbon target. The laser used is of high average power and ultra-fast pulsing. According to various preferred embodiments, the laser produces and output above about 50 watts/cm2 at a repetition rate above about 15 MHz and exhibits a pulse duration below about 10 picoseconds. The carbon, carbon/catalyst target and the laser beam are moved relative to one another and a focused flow of “side pumped”, preheated inert gas is introduced near the point of ablation to minimize or eliminate interference by the ablated plume by removal of the plume and introduction of new target area for incidence with the laser beam. When the target is moved relative to the laser beam, rotational or translational movement may be imparted thereto, but rotation of the target is preferred.
摘要:
Disclosed are methods of purifying mixtures comprising nanofibers and/or nanotubes and residual catalyst particles that are covered by outer layers of the nanotube or nanofiber material. The mixtures are exposed to electromagnetic radiation, which induces localized heating in the residual catalyst particles. The localized heating creates breaches in the outer layers. Thereafter, the residual catalyst particles may be removed under relatively mild conditions that do not significantly affect the structural integrity of the nanotubes or nanofibers. The methods of the invention have been used to particular advantage in the purification of single wall carbon nanotubes (SWNTs) synthesized using metal catalysts. For these SWNTs, microwave radiation is preferably used to induce the localized heating, the outer layers are preferably removed at least in part by carrying out the localized heating under air, and the residual catalyst may be removed by exposure to relatively dilute aqueous acid.
摘要:
The present invention generally relates to methods and apparatus for the synthesis or preparation of boron-doped single-walled carbon nanotubes (B-SWCNTs). The invention provides a high yield, single step method for producing large quantities of continuous macroscopic carbon fiber from single-wall carbon nanotubes using inexpensive carbon feedstocks wherein the carbon nanotubes are produced by in situ boron substitutional doping. In one embodiment, the nanotubes disclosed are used, singularly or in multiples, in power transmission cables, in solar cells, in batteries, as antennas, as molecular electronics, as probes and manipulators, and in composites. It is another object of this invention to provide macroscopic carbon fiber made by such a method.
摘要:
Compounds consisting of two or more fullerenes (e.g., a C.sub.60 dimer) and a film or powder which includes covalently linked fullerene molecules. Also disclosed is a fullerene film or powder with gas molecules or atoms uniformly disposed therein, as well as a method of diffusing gas molecules or atoms into or through a film or powder made of pristine fullerene molecules.
摘要:
Nano-encapsulated photosensitizers and their use in the treatment of tumors and/or imaging is described. Preferably, the photosensitizers are encapsulated in a calcium phosphate nanoparticle (CPNP). Encapsulating the PS in a CPNP increases the half-life of the PS, increases absorption of the PS into the target cell tissue, increases the photostability of the PS, increases the photoefficiency of the PS, increases in vivo retention of the PS, or combinations thereof, ultimately making it a highly efficacious agent for use in photodynamic therapy, imaging target tissues, vessels, or tumors, and/or detecting or locating tumors.
摘要:
Carbon structures, e.g. carbon nano-fibers, suitable for absorbing hydrogen at low pressures and low temperatures are produced by a selective oxidation and/or acid reflux process. The process includes heating an impure mixture containing a crystalline form of carbon in the presence of an oxidizing gas at a temperature and time sufficient to selectively oxidize and remove a substantial amount of any amorphous carbon impurities from the mixture. Metal containing impurities can be removed from the mixture by exposing the desired carbon and accompanying impurities to an acid to produce a carbon fiber that is substantially free of both non-fiber carbon impurities and metal impurities. Another aspect of the present invention includes purified carbon structures that can store hydrogen at low pressures and temperatures.
摘要:
Single walled carbon nanotubes are produced in a novel apparatus by the laser-induced ablation of moving carbon target. The laser used is of high average power and ultra-fast pulsing. According to various preferred embodiments, the laser produces an output above about 50 watts/cm2 at a repetition rate above about 15 MHz and exhibits a pulse duration below about 10 picoseconds. The carbon, carbon/catalyst target and the laser beam are moved relative to one another and a focused flow of “side pumped”, preheated inert gas is introduced near the point of ablation to minimize or eliminate interference by the ablated plume by removal of the plume and introduction of new target area for incidence with the laser beam. When the target is moved relative to the laser beam, rotational or translational movement may be imparted thereto, but rotation of the target is preferred.
摘要:
The present invention is directed towards a method of producing single wall carbon nanotubes which comprises providing a catalyst comprising an alumina support and a component selected from the group consisting of reduced Fe, reduced Fe/Mo, Fe oxide, and Fe/Mo oxide, and growing, in an inert atmosphere, single wall carbon nanotubes by passing a gas comprising methane over the catalyst at a temperature and for a time sufficient to grow single wall carbon nanotubes. The invention is also directed towards a single wall carbon nanotube produced by such a method. The invention is also directed towards a catalyst for producing SWNTs, wherein the catalyst comprises an alumina support and a component selected from the group consisting of reduced Fe, reduced Fe/Mo, Fe oxide, and Fe/Mo oxide.