Patent US5698175A successfully refreshed from Google Patents.
US5698175A
Expired / Lapsed
US
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Process for purifying, uncapping and chemically modifying carbon nanotubes
Assignee: NEC Corp
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Filing: 1995-07-03
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Granted: 1997-12-16
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Expires: 2015-07-03
Abstract
Abstract Disclosed is a process for purifying carbon nanotubes which has steps of 1) mixing carbon nanotubes which accompany carbon impurities with a reagent selected from a group consisting of oxidation agents, nitration agents and sulfonation agents in liquid phase, 2) reacting the carbon nanotubes with the reagent at a predetermined temperature in the liquid phase, wherein the carbon impurities except carbon nanotubes are selectively reacted to dissolve in the liquid phase, and 3) separating carbon nanotubes from which the impurities were released from the liquid phase then washing and drying it. A process for uncapping carbon nanotubes and a process for chemically modifying carbon nanotubes are also disclosed.
Inventors
- 👤 Hidefumi Hiura
- 👤 Thomas Ebbesen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:10
CPC Classifications
B; B82; B82Y; B82Y30/00; C; C01; C01B; C01B32/00; C01B32/15; C01B32/158; C01B32/168; C01B32/174; B82Y40/00; C01B32/17; Y; Y10; Y10S; Y10S977/00; Y10S977/70; Y10S977/734; Y10S977/742; Y10S977/743; Y10S977/745; Y10S977/84; Y10S977/842; Y10S977/845; Y10S977/846; Y10S977/888; Y10S977/895; Y10S977/896
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
84 words
A process for purifying carbon nanotubes, comprising: combining a mixture of carbon nanotubes and accompanying carbon impurities, with a reagent selected from the group consisting of liquid phase oxidation agents, liquid phase nitration agents, and liquid phase sulfonation agents; reacting said mixture with said reagent at a temperature effective to selectively dissolve said carbon impurities in the liquid phase, thereby releasing carbon nanotubes from said impurities; and separating said released carbon nanotubes from said liquid phase and subsequently washing and drying said carbon nanotubes.
Claim 2
Dependent Claim
84 words
A process for purifying carbon nanotubes, comprising: combining a mixture of carbon nanotubes and accompanying carbon impurities, with a reagent selected from the group consisting of liquid phase oxidation agents, liquid phase nitration agents, and liquid phase sulfonation agents; reacting said mixture with said reagent at a temperature effective to selectively dissolve said carbon impurities in the liquid phase, thereby releasing carbon nanotubes from said impurities; and separating said released carbon nanotubes from said liquid phase and subsequently washing and drying said carbon nanotubes.
Claim 3
Dependent Claim
21 words
A process for purifying carbon nanotubes, according to claim 1, wherein said temperature is about 120 to about 180 degrees Celsius.
Claim 4
Dependent Claim
69 words
A process for uncapping carbon nanotubes, comprising: mixing carbon nanotubes which are capped by carbon fragments at the tips thereof with a reagent selected from the group consisting of liquid phase oxidation agents, liquid phase nitration agents, and liquid phase sulfonation agents; and reacting said carbon nanotubes with said reagent in the liquid phase at a temperature effective to selectively dissolve said carbon fragments, thereby uncapping said carbon nanotubes.
Claim 5
Dependent Claim
69 words
A process for uncapping carbon nanotubes, comprising: mixing carbon nanotubes which are capped by carbon fragments at the tips thereof with a reagent selected from the group consisting of liquid phase oxidation agents, liquid phase nitration agents, and liquid phase sulfonation agents; and reacting said carbon nanotubes with said reagent in the liquid phase at a temperature effective to selectively dissolve said carbon fragments, thereby uncapping said carbon nanotubes.
Claim 6
Dependent Claim
21 words
A process for uncapping carbon nanotubes, according to claim 3, wherein said temperature is about 120 to about 180 degrees Celsius.
Claim 7
Dependent Claim
75 words
A process for chemically modifying carbon nanotubes, comprising: mixing carbon nanotubes which are crude or purified with a liquid phase reagent having nitro-, sulfo-, carboxyl-, carbonyl-, ether, or phenolic hydroxyl-functional group or a mixed reagent of at least two of said reagents in liquid phase; and reacting said carbon nanotubes with said reagent or said mixed reagents at a temperature effective to introduce said functional group or groups into said nanotubes in the liquid phase.
Claim 8
Dependent Claim
75 words
A process for chemically modifying carbon nanotubes, comprising: mixing carbon nanotubes which are crude or purified with a liquid phase reagent having nitro-, sulfo-, carboxyl-, carbonyl-, ether, or phenolic hydroxyl-functional group or a mixed reagent of at least two of said reagents in liquid phase; and reacting said carbon nanotubes with said reagent or said mixed reagents at a temperature effective to introduce said functional group or groups into said nanotubes in the liquid phase.
Claim 9
Dependent Claim
22 words
A process for chemically modifying carbon nanotubes, according to claim 5, wherein said temperature is about 120 to about 150 degrees Celsius.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-12-15 | 2001-06-16 | 2001-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-12-15 | 2005-06-16 | 2005-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-12-15 | 2009-06-16 | 2009-12-16 | $7700.00 | Window Closed / Lapsed |