William Marsh Rice University

Wan-Ting Chiang

Richard E Smalley

Robert H Hauge

Rajesh Kumar Saini

Daniel T Colbert

Ken A Smith

Kenneth A Smith

Chad Huffman

Zhenning Gu

Yuemei Yang

Boris I Yakobson

Robert H Hague

Michael J Casavant

Deron A Walters

Wilber Carter Kittrell

Chad B Huffman

Robert H Rice Univers Mailstop Chem Ms60 Hauge

Xiao Chuan Qin

Boris I Rice Univ Mech Eng & Mat Sci Yakobson

The present invention relates to an all gas-phase process for the purification of single-wall carbon nanotubes and the purified single-wall carbon nanotube material. Known methods of single-wall carbon nanotube production result in a single-wall carbon nanotube product that contains single-wall carbon nanotubes in addition to impurities including residual metal catalyst particles and amounts of small amorphous carbon sheets that surround the catalyst particles and appear on the sides of the single-wall carbon nanotubes and 'ropes' of single-wall carbon nanotubes. The purification process removes the extraneous carbon as well as metal-containing residual catalyst particles. The process comprises oxidation of the single-wall carbon nanotube material, reduction and reaction of a halogen-containing gas with the metal-containing species. The oxidation step may be done dry or in the presence of water vapor. The present invention provides a scalable means for producing high-purity single-wall carbon nanotube material.

Gas-phase process for purifying single-wall carbon nanotubes and compositions thereof

The present invention is directed to the creation of macroscopic materials and objects comprising aligned nanotube segments. The invention entails aligning single-wall carbon nanotube (SWNT) segments that are suspended in a fluid medium and then removing the aligned segments from suspension in a way that macroscopic, ordered assemblies of SWNT are formed. The invention is further directed to controlling the natural proclivity of nanotube segments to self assemble into ordered structures by modifying the environment of the nanotubes and the history of that environment prior to and during the process. The materials and objects are &ldquo;macroscopic&rdquo; in that they are large enough to be seen without the aid of a microscope or of the dimensions of such objects. These macroscopic, ordered SWNT materials and objects have the remarkable physical, electrical, and chemical properties that SWNT exhibit on the microscopic scale because they are comprised nanotubes, each of which is aligned in the same direction and in contact with its nearest neighbors. An ordered assembly of closest SWNT also serves as a template for growth of more and larger ordered assemblies. An ordered assembly further serves as a foundation for post processing treatments that modify the assembly internally to specifically enhance selected material properties such as shear strength, tensile strength, compressive strength, toughness, electrical conductivity, and thermal conductivity.

Macroscopic ordered assembly of carbon nanotubes

The present invention relates to a process for the purification of single-wall carbon nanotubes and the purified single-wall carbon nanotube material. Known methods of single-wall carbon nanotube production result in a single-wall carbon nanotube product that contains single-wall carbon nanotubes in addition to impurities including residual metal catalyst particles and amounts of small amorphous carbon sheets that surround the catalyst particles and appear on the sides of the single-wall carbon nanotubes and &ldquo;ropes&rdquo; of single-wall carbon nanotubes. The purification process removes the extraneous carbon as well as metal-containing residual catalyst particles. The process employs steps including a gas-phase oxidation of the amorphous carbon and subsequent liquid-phase reaction of a halogen-containing acid with the metal-containing species. Optionally, the single-wall carbon nanotube material may be annealed dry or in the presence of moisture. The present invention provides a scalable means for producing high-purity single-wall carbon nanotube material.

Process for purifying single-wall carbon nanotubes and compositions thereof

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Ponca City, OK, United States of America

Wan-Ting Chiang