摘要:
Method and apparatus for accurately and instantaneously determining the thermodynamic temperature of remote objects by continuous determination of the emissivity, the reflectivity, and optical constants, as well as the apparent or brightness temperature of the sample with a single instrument. The emissivity measurement is preferably made by a complex polarimeter including a laser that generates polarized light, which is reflected from the sample into a detector system. The detector system includes a beamsplitter, polarization analyzers, and four detectors to measure independently the four Stokes vectors of the reflected radiation. The same detectors, or a separate detector in the same instrument, is used to measure brightness temperature. Thus, the instrument is capable of measuring both the change in polarization upon reflection as well as the degree of depolarization and hence diffuseness. This enables correction for surface roughness of the sample and background radiation, which could otherwise introduce errors in temperature measurement.
摘要:
The present invention is directed to a method for depositing diamond films and particles on a variety of substrates by flowing a gas or gas mixture capable of supplying (1) carbon, (2) hydrogen and (3) a halogen through a reactor over the substrate material. The reactant gases may be pre-mixed with an inert gas in order to keep the overall gas mixture composition low in volume percent of carbon and rich in hydrogen. Pre-treatment of the reactant gases to a high energy state is not required as it is in most prior art processes for chemical vapor deposition of diamond. Since pre-treatment is not required, the process may be applied to substrates of virtually any desired size, shape or configuration.The reactant gas mixture preferably is passed through a reactor, a first portion of which is heated to a temperature of from about 400.degree. C. to about 920.degree. C. and more preferably from about 800.degree. C. to about 920.degree. C. The substrate on which the diamond is to be grown is placed in the reactor in a zone that is maintained at a lower temperature of from about 250.degree. C. to about 750.degree. C., which is the preferred diamond growth temperature range. The process preferably is practiced at ambient pressures, although lower or higher pressures may be used. Significant amounts of pure diamond films and particles have been obtained in as little as eight hours. The purity of the diamond films and particles has been verified by Raman spectroscopy and powder x-ray diffraction techniques.
摘要:
A method for cutting single-wall carbon nanotubes involves partially fluorinating single-wall carbon nanotubes and pyrolyzing the partially fluorinated nanotubes in an inert atmosphere or vacuum up to about 1000° C. The nanotubes are optionally purified before cutting. The partial fluorination involves fluorinating the nanotubes to a carbon-fluorine stoichiometry of CFx, where x is up to about 0.3. The invention also relates to the derivatization of fluorinated and cut single-wall carbon nanotubes. The single-wall carbon nanotubes can be cut to any length depending on the fluorination and pyrolysis conditions. Short nanotubes are useful in various applications, such as field emitters for flat panel displays and as “seeds” for further nanotube growth.
摘要:
The present invention is directed to a method for depositing diamond films and particles on a variety of substrates by flowing a gas or gas mixture capable of supplying (1) carbon, (2) hydrogen, (3) a halogen and, preferably, (4) a chalcogen through a reactor over the substrate material. The reactant gases may be premixed with an inert gas in order to keep the overall gas mixture composition low in volume percent of carbon and rich in hydrogen. Pre-treatment of the reactant gases to a high energy state is not required as it is in most prior art processes for chemical vapor deposition of diamond. Since pretreatment is not required, the process may be applied to substrates of virtually any desired size, shape or configuration.
摘要:
A method for functionalizing the wall of single-wall or multi-wall carbon nanotubes involves the use of acyl peroxides to generate carbon-centered free radicals. The method allows for the chemical attachment of a variety of functional groups to the wall or end cap of carbon nanotubes through covalent carbon bonds without destroying the wall or endcap structure of the nanotube. Carbon-centered radicals generated from acyl peroxides can have terminal functional groups that provide sites for further reaction with other compounds. Organic groups with terminal carboxylic acid functionality can be converted to an acyl chloride and further reacted with an amine to form an amide or with a diamine to form an amide with terminal amine. The reactive functional groups attached to the nanotubes provide improved solvent dispersibility and provide reaction sites for monomers for incorporation in polymer structures. The nanotubes can also be functionalized by generating free radicals from organic sulfoxides.
摘要:
A lubricant for improved performance in glass molding. The lubricant is smokeless, odorless, non-toxic and non-combustible. It is applied infrequently, such as once a shift or less. The lubricant is carbon monofluoride (CF.sub.x).sub.n wherein "x" is about 0.7 or, preferably, above 1.00. Novel methods of application of the lubricant are disclosed.
摘要:
The present invention is directed to methods of integrating carbon nanotubes into epoxy polymer composites via chemical functionalization of carbon nanotubes, and to the carbon nanotube-epoxy polymer composites produced by such methods. Integration is enhanced through improved dispersion and/or covalent bonding with the epoxy matrix during the curing process. In general, such methods involve the attachment of chemical moieties (i.e., functional groups) to the sidewall and/or end-cap of carbon nanotubes such that the chemical moieties react with either the epoxy precursor(s) or the curing agent(s) (or both) during the curing process. Additionally, in some embodiments, these or additional chemical moieties can function to facilitate dispersion of the carbon nanotubes by decreasing the van der Waals attractive forces between the nanotubes.
摘要:
This invention is directed to making chemical derivatives of carbon nanotubes and to uses for the derivatized nanotubes, including making arrays as a basis for synthesis of carbon fibers. In one embodiment, this invention also provides a method for preparing single wall carbon nanotubes having substituents attached to the side wall of the nanotube by reacting single wall carbon nanotubes with fluorine gas and recovering fluorine derivatized carbon nanotubes, then reacting fluorine derivatized carbon nanotubes with a nucleophile. Some of the fluorine substituents are replaced by nucleophilic substitution. If desired, the remaining fluorine can be completely or partially eliminated to produce single wall carbon nanotubes having substituents attached to the side wall of the nanotube. The substituents will, of course, be dependent on the nucleophile, and preferred nucleophiles include alkyl lithium species such as methyl lithium. Alternatively, fluorine may be fully or partially removed from fluorine derivatized carbon nanotubes by reacting the fluorine derivatized carbon nanotubes with various amounts of hydrazine, substituted hydrazine or alkyl amine. The present invention also provides seed materials for growth of single wall carbon nanotubes comprising a plurality of single wall carbon nanotubes or short tubular molecules having a catalyst precursor moiety covalently bound or physisorbed on the outer surface of the sidewall to provide the optimum metal cluster size under conditions that result in migration of the metal moiety to the tube end.
摘要:
The present invention is directed to methods of integrating carbon nanotubes into epoxy polymer composites via chemical functionalization of carbon nanotubes, and to the carbon nanotube-epoxy polymer composites produced by such methods. Integration is enhanced through improved dispersion and/or covalent bonding with the epoxy matrix during the curing process. In general, such methods involve the attachment of chemical moieties (i.e., functional groups) to the sidewall and/or end-cap of carbon nanotubes such that the chemical moieties react with either the epoxy precursor(s) or the curing agent(s) (or both) during the curing process. Additionally, in some embodiments, these or additional chemical moieties can function to facilitate dispersion of the carbon nanotubes by decreasing the van der Waals attractive forces between the nanotubes.
摘要:
This invention is directed to making chemical derivatives of carbon nanotubes and to uses for the derivatized nanotubes, including making arrays as a basis for synthesis of carbon fibers. In one embodiment, this invention also provides a method for preparing single wall carbon nanotubes having substituents attached to the side wall of the nanotube by reacting single wall carbon nanotubes with fluorine gas and recovering fluorine derivatized carbon nanotubes, then reacting fluorine derivatized carbon nanotubes with a nucleophile. Some of the fluorine substituents are replaced by nucleophilic substitution. If desired, the remaining fluorine can be completely or partially eliminated to produce single wall carbon nanotubes having substituents attached to the side wall of the nanotube. The substituents will, of course, be dependent on the nucleophile, and preferred nucleophiles include alkyl lithium species such as methyl lithium. Alternatively, fluorine may be fully or partially removed from fluorine derivatized carbon nanotubes by reacting the fluorine derivatized carbon nanotubes with various amounts of hydrazine, substituted hydrazine or alkyl amine. The present invention also provides seed materials for growth of single wall carbon nanotubes comprising a plurality of single wall carbon nanotubes or short tubular molecules having a catalyst precursor moiety covalently bound or physisorbed on the outer surface of the sidewall to provide the optimum metal cluster size under conditions that result in migration of the metal moiety to the tube end.