Chemistry: electrical and wave energy – Processes and products – Processes of treating materials by wave energy
Reexamination Certificate
2006-03-21
2006-03-21
Silverman, Stanley S. (Department: 1754)
Chemistry: electrical and wave energy
Processes and products
Processes of treating materials by wave energy
C423S447100, C423S461000, C502S027000, C502S056000
Reexamination Certificate
active
07014737
ABSTRACT:
Disclosed are methods of purifying mixtures comprising nanofibers and/or nanotubes and residual catalyst particles that are covered by outer layers of the nanotube or nanofiber material. The mixtures are exposed to electromagnetic radiation, which induces localized heating in the residual catalyst particles. The localized heating creates breaches in the outer layers. Thereafter, the residual catalyst particles may be removed under relatively mild conditions that do not significantly affect the structural integrity of the nanotubes or nanofibers. The methods of the invention have been used to particular advantage in the purification of single wall carbon nanotubes (SWNTs) synthesized using metal catalysts. For these SWNTs, microwave radiation is preferably used to induce the localized heating, the outer layers are preferably removed at least in part by carrying out the localized heating under air, and the residual catalyst may be removed by exposure to relatively dilute aqueous acid.
REFERENCES:
Ilijima et al, Single-Shell Carbon Nanotubes Of 1-NM Diameter, Nature, (1993) pp. 603-605.
Bethune et al, Cobalt-Catalysed Growth of Carbon Nanotubes With Single-Atomic-Layer Walls, Nature, (1993) pp. 605-607.
Tohji et al, Purification Procedure For Single-Walled Nanotubes, J. Phys. Chem. B, 101 (1997) pp. 1974-1978.
Shi et al, Purification of Single-Wall Carbon Nanotubus, Solid State Communications, 112 (1999) pp. 35-37.
Mizoguti et al; Purification of Single-Wall Carbon Nanotubes By Using Ultrafine Gold Particles, Chemical Physics Letters, 321 (2000) pp. 297-301.
Zimmerman et al, Gas-Phase Purification Of Single-Wall Carbon Nanotubes, Chem. Mater, 12 (2000) pp. 1361-1366.
Dujardin et al, Wetting of Single Shell Carbon Nanotubes, 10 (1998) pp. 1472-1475.
Rinzler et al, Large-Scale Purification Of Single-Wall Carbon Nanotubes: Process Product, And Characterization, Appl. Phys. 67 (1998) pp. 29-37.
Dillion et al, A Simple And Complete Purification of Single-Wall Carbon Nanotube Materials, Adv. Mater, 11 (1999) pp. 1354-1358.
Bandow et al, Purification of Single-Wall Carbon Nanotubes By Microfiltration, J. Phys. Chem. 101 (1997) pp. 8839-8842.
Shelimov et al, Purification of Single-Wall Carbon Nanotubes By Ultrasonically Assisted Filtration, Chemical Physics Letter, 282 (1998) pp. 429-434.
Harutyunyan et al, Purification of SWNTs Using Microwave Heating, Mat. Res. Soc. Symp. Proc., 706 (2002) pp. Z2.8.1-Z2.8.5.
Roy et al, Full sintering Of Powder-Metal Bodies in A Microwave Field, Nature 399 (1999) pp. 668-670.
Kim et al. The Interaction Of Hydrocarbons With Copper-Nickel And Nickel In The Formation of Carbon Filaments, Journal Of Catalyst 131 (1991) pp. 60-73.
Eklund et al, Vibrational Modes Of Carbon Nanotubes; Spectroscopy And Theory, Carbon, 33 (1995) pp. 959-972.
Endo et al, Raman Spectroscopic Characterization Of Submicron Vapor-Grown Carbon Fibers And Carbon Nanofibers Obtained By Pyrolyzing Hydrocarbons, J. Mater. Res. 14 (1999) pp. 4474-4477.
Pradhan et al. Large Cryogenic Storage Of Hydrogen In Carbon Nanotubes At Low Pressures, Mat. Res. Soc. Symp. Proc., 706 (2002) pp. Z10.3.1-Z10.3.6.
Moon et al; High-Yeild Purification Process Of Singlewalled Carbon Nanotubes; J. Phys. Chem. (2001) 105 pp. 5677-5681.
Chiang et al; Purification And Characterization Of Single-Wall Carbon Nanotubes; J. Phys. Chem (2001) 105 pp. 1157-1161.
Eklund Peter C.
Harutyunyan Avetik
Pradhan Bhabendra K.
Lish Peter
McDermott Will & Emery LLP
Penn State Research Foundation
Silverman Stanley S.
LandOfFree
Method of purifying nanotubes and nanofibers using... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of purifying nanotubes and nanofibers using..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of purifying nanotubes and nanofibers using... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3529132