Title of Invention

A METHOD OF MANUFACTURE OF CARBON NANOTUBES AND SUCH TUBES WHENEVER SO MANUFACTURED

Abstract A method of manufacture of cabon nanotubes which comprises the mixing of mesoporous material, water and fine clay particles (as binder). The resulting mixture is stirred, dried and activated at 550 deg.c to obtain a mesoporous composite membrane (MCM) by employing a carbon source, such as a polymer or a hydrocarbon with respect to the MCM which is then carbonized by heating the same to obtain a carbon/MCM composite). Carbon nanotubes are obtained when the said C/MCM is immersed in hydrofluoric acid to dissolve the MCM.
Full Text This invention relates to a method of manufacture of carbon nanotubes and such tubes when so manufactured.
The carbon nanotubes manufactured by the mediod proposed herein are useful in the manufacture of electrodes for fuel celts. In hydrogen storage and heterogeneous catidysts. Such nanotubes are particularly a|>plicable to the automobile and electronic industries.
The method of manufacture of carbon nanotubes, accordmg to this invention, comprises the steps of mixing of mesoporous material, water and fme clay particles (as binder) the resulting mixture being stirred, dried and activate at 550 degree C to obtain mesoporous composite membrane (MCM); employing a carbon source such as, a polymer or a hydrocarbon with respect to the MCM; carbonising the same by heating, to obtain a carbon/MCM composite (C/MCM composite); immersing the said C/MCM in hydrofluoric acid or in hexachloro platinic acid and then in hydrofluoric acid to dissolve the MCM leaving carbon nanotubes or metal filled nanotubes.
Metal filled nanotubes are manufactured by following

the above method and Immersing the C/MCM composite in aqueous hexachloro platlnic acid solution , drying and reducing in hydrogen atmosphere before dissolving the MCM in hydrofluoric acid.
This invention will now be described in further detail with reference to the single Figure in the accompanying drawings which illustrates, by way of example, and not by way of limitation, a flow chart depicting one of various modes of carrying out the method proposed herein.
EXAMPLE
0.6 g of silicious material and 0.4 g of fine clay particles are mixed together in 30 ml. distilled water and the resultant is stirred for 24 hours. The clay is intended to act as a binder.
The resulting homogeneous suspension is poured into a petrldlsh and dried at room temperature for 48 hours. The membrane, so obtained, is then further dried at 120 deg. C overnight and activated at 550 deg. C overnight to increase mechanical stability. The membrane thus obtained Is ultrasonlcated for 30 min.

and was found to be quite stable for ultrasonication.
Polypyrrole which is a carbon source is coated on to the MCM and carbonised by heating in argon atmosphere to 850 deg. C to obtain a carbon/MCM composite. The said composite is then immersed in 48% hydrofluoric acid to dissolve the MCM, leaving carbon nanotubes.
To obtain metal filled carbon nanotubes, the above procedure is followed except that after carbonisation, the C/MCM is immersed in 73 mM aqueous hexachloro platinic acid solution for 6 hours, dried and reduced in hydrogen atmosphere for 5 hours at 580 deg. C. The membrane is then immersed in hydrofluoric acid to dissolve the MCM, leaving metal filled nanotubes.
The terms and expressions in this specification are of description and not of limitation, there being no Intention to exclude any equivalents of the features illustrated and described, but it is understood that various other modes of carrying out the method herein are possible without departing from the scope and ambit of this invention.


We Claim:
1. A method of manufacture of carbon nanotubes comprising the steps of mixing of mesoporous material, water and fine clay particles (as binder) the resulting mixture being stirred, dried and activated at SSO degree C to obtain a mesoporous composite membrane (MCM); employing a carbon source such as, a polymer or a hydrocarbon with respect to the MCM; carbonising the same by heating, to obtain a carbon/MCM composite (C/MCM composite); immersing the said C/MCM in hydrofluoric acid or in hexachloro platinic acid and then in hydrofluoric acid to dissolve the MCM leaving carbon nanotubes or metal filled nanotubes.
2. A method as claimed in Claim 1 wherein the mesoporous material is silicious material, the said material and clay particles being mixed and stirred for 24 hours at room temperitfure.
3. A method as claimed in Claim 2 wherein the stirred mix is dried for 48 hours at room temperature, dried overnight at 120 degree C before being activated overnight SSO degree C.
4.A method as claimed in any one of the

preceding Claims wherein the polymer is a polypyrrole.
5. A method as claimed in any one of the preceding Claims wherein the carbonisation is carried out by heating in argon atmosphere at 850 deg. C.
6. A method as claimed in any one of the preceding Claims wherein, after carbonisation, the C/MCM composite is immersed in 73 mM aqueous hexachloro platinic acid solution for 6 hours, dried and reduced in hydrogen atmosphere for 5 hours at 580 deg. C.
7. A method as claimed in any one of the preceding Claims 1 to 5 wherein the C/MCM composite is immersed in 4B% hydrofluoric acid to dissolve the MCM leaving carbon nanotubes.
8. A method as claimed in Claim 6 wherein the C/MCM composite is immersed in 46X hydrofluoric acid to dissolve the MCM leaving metal filled carbon nanotubes.
9. A method of manufacture of carbon nanotubes
substantially as herein described and illustrated.

10. Carbon nanotubes as manufacturable by a method as claimed in any one of the preceding Claims.

Documents:

0384-mas-2001 abstract duplicate.pdf

0384-mas-2001 abstract.pdf

0384-mas-2001 claims duplicate.pdf

0384-mas-2001 claims.pdf

0384-mas-2001 correspondence others.pdf

0384-mas-2001 correspondence po.pdf

0384-mas-2001 description (complete) duplicate.pdf

0384-mas-2001 description (complete).pdf

0384-mas-2001 drawings.pdf

0384-mas-2001 form-1.pdf

0384-mas-2001 form-19.pdf

0384-mas-2001 form-26.pdf


Patent Number 199123
Indian Patent Application Number 384/MAS/2001
PG Journal Number 08/2007
Publication Date 23-Feb-2007
Grant Date 01-Mar-2006
Date of Filing 11-May-2001
Name of Patentee M/S. INDIAN INSTITUTE OF TECHNOLOGY
Applicant Address IIT POST BOX, CHENNAI 600 036
Inventors:
# Inventor's Name Inventor's Address
1 BALASUBRAMANIAN VISWANATHAN INDIAN INSTITUTE OF TECHNOLOGY, IIT POST BOX, CHENNAI 600 036,
2 BASHYAM RAJESH INDIAN INSTITUTE OF TECHNOLOGY, IIT POST BOX, CHENNAI 600 036,
PCT International Classification Number B82B 3/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA