US Patent 7244694 - Nanotube viscoelastic fluid

http://www.freepatentsonline.com/7244694.html

Viscoelastic fluids have been used in the past in order to extract oil from oil fields. This patent claims the use of nanotubes to use such fluids at higher temperatures and less fluid loss. Claim 1 reads:

1. A viscoelastic nanotube fluid composition comprising: an aqueous medium; an amount of a viscoelastic surfactant effective to render said aqueous medium viscoelastic; a member selected from the group consisting of organic acids, organic acid salts, inorganic salts, and combinations of one or more organic acids or organic acid salts with one or more inorganic salts; and, a nanotube component effective to impart increased viscosity to said fluid composition at temperatures of up to about 150 C.

US Patent 7244408 - MWCNT distribution by arc discharge

http://www.freepatentsonline.com/7244408.html

Carbon nanotubes used in composites often have lengths exceeding 1 micron. This patent is focused on methods of making shorter nanotubes of a particular diameter distribution using the arc discharge method. Although, I'm not exactly certain why this would be useful (the application cites "more suitable for certain applications" without going into specifics). Claim 1 reads:

1. Nanotubes comprising of short multi-walled nanotubes (sh-MWNTs) formed from concentrically arranged nanotube layers having a mean outer diameter of from 2 to 15 nm, a median outer diameter of 6 to 8 nm and a natural length of 100 to 500 nm.

US Patent 7217404 - Photoinduced combustion of carbon nanotubes

http://www.freepatentsonline.com/7217404.html

Several years back an undergraduate student at Rensselaer Polytechnic Institute was taking some flash photographs in a lab and accidentally ignited a clump of single-walled carbon nanotubes (see article at http://www.sciam.com/article.cfm?articleID=0006C256-22D2-1CD0-B4A8809EC588EEDF)

It appears as if the researchers in the lab filed a patent for the effect which has issued with a fairly broad claim reading:

1. A method of transforming a single-walled carbon nanotube (SWNT) comprising exposing the SWNT to light having a power sufficient to ignite the SWNT, wherein the SWNT is ignited by the light.

US Patent 7217374 - Carbon nanotube mesh resistor

http://www.freepatentsonline.com/7217374.html

This patent from Fuji Xerox proposes improved resistor material formed using carbon nanotubes including cross-linking the nanotubes via a polymerization reaction. Claim 1 reads:

1. A resistance element comprising an electrical resistance body consisting of a patterned carbon nanotube structure having a mesh structure, in which plural carbon nanotubes are cross-linked to one another through cross-linked sites.

US Patent 7211320 - CNT sieve

http://www.freepatentsonline.com/7211320.html

This patent proposes using carbon nanotubes for desalination/sterilization purposes by intentionally causing defects in the carbon rings to more easily separate contaminates from fluids. Claim 1 reads:


1. A material for reducing contaminants in a fluid, said material comprising: carbon nanotubes, and a porous support medium for said carbon nanotubes, said porous support medium being permeable to the flow of said fluid, wherein a plurality of said carbon nanotubes comprise: a lattice distortion, at least one functional group, and are fused or bonded to said porous support medium, to another carbon nanotube, or to a combination thereof.