Scalable nanotube fabrics and methods for making same
The present disclosure provides scalable nanotube fabrics and methods for controlling or otherwise adjusting the nanotube length distribution of a nanotube application solution in order to realize scalable nanotube fabrics. In one aspect of the present disclosure, one or more filtering operations are used to remove relatively long nanotube elements from a nanotube solution until nanotube length distribution of the nanotube solution conforms to a preselected or desired nanotube length distribution profile. In another aspect of the present disclosure, a sono-chemical cutting process is used to break up relatively long nanotube elements within a nanotube application solution into relatively short nanotube elements to realize a pre-selected or desired nanotube length distribution profile.
1. A method for forming a scalable nanotube fabric comprising:
contacting a plurality of nanotubes with a liquid medium to obtain a nanotube solution;
performing at least one nanotube length distribution adjustment process on said nanotube solution;
depositing said nanotube solution over a material layer to form a nanotube fabric layer, wherein
at least one of said at least one nanotube length distribution adjustment processes is a sono-chemical cutting process, and wherein
a gas pressure used within said sono-chemical cutting process is selected from within the range between a vapor pressure of water and one atmosphere (1 ATM), and wherein
the gas pressure is selected by bubbling a gas through said nanotube solution during said sono-chemical cutting process.
2. The method of claim 1 wherein said at least one nanotube length distribution adjustment processes additionally includes a filtering process.
3. The method of claim 2 wherein said filtering process adjusts the mean nanotube length within a filtered nanotube solution to within a range between 5 nm and 5 μm.
4. The method of claim 1 wherein said sono-chemical cutting process adjusts the mean nanotube length within a filtered/centrifugated/chemical treated nanotube solution to a range between 5 nm and 5 μm.
5. The method of claim 1 wherein said sono-chemical cutting process uses a sulfuric acid-nitric acid mixture.
6. The method of claim 1 wherein said gas is one of argon, xenon, ozone, and H 2 O 2 .
7. The method of claim 1 wherein said at least one nanotube length distribution adjustment processes additionally includes a centrifugation process.
8. The method of claim 1 wherein said plurality of nanotubes are carbon nanotubes.