Graphene-hybridized concentric carbon nanotube hybrid material

Abstract

A material that includes a plurality of exfoliated carbon nanotubes, each exfoliated carbon nanotube having multiple walls and an outer diameter in the range of subnanometers to tens of nanometers, and having at least one end capped, for example, with half of a fullerene molecule.

Description

TITLEGRAPHENE-HYBRIDIZED CONCENTRICCARBON NANOTUBE HYBRID MATERIALBACKGROUND

[0001] The disclosed subject matter relates to a novel carbon allotrope, more particularly a graphene-hybridized concentric carbon nanotube hybrid material.

[0002] U.S. Patent Application Publication No. 2011 / 0294013, hereby incorporated by reference in its entirety, discloses exfoliated carbon nanotubes, methods for the production of exfoliated carbon nanotubes. Nevertheless, the performance of exfoliated carbon nanotubes can be improved.BRIEF SUMMARY OF THE INVENTION

[0003] The present disclosure provides a material that includes a plurality of exfoliated carbon nanotubes, each exfoliated carbon nanotube having multiple walls and an outer diameter in the range of subnanometers to tens of nanometers, and having at least one end capped. In certain embodiments, each exfoliated carbon nanotube is full length, preferably having a length of from about 0.2 pm to about 5 pm. The outer diameter of each exfoliated carbon nanotube can be from about 0.1 to about 10 nanometers, preferably about 0.31 nanometers on average.

[0004] In certain embodiments, any one or more of the materials described in this application may further include having one more nanotubes in which one end is capped with half of a fullerene molecule. In exemplary embodiments, at least half, or at least 60%, or at least 75% of the nanotubes respectively capped with half of a fullerene molecule.

[0005] In certain embodiments, one or more, or each exfoliated carbon nanotube comprises from 5 to 10 concentric single-walled nanotubes. In certain embodiments, the material has a thickness of 0.18 nm to 5 nm and an apparent density lower than 0.03 g / cm3. In certain embodiments, the material has an electrical conductivity of 800 to 1200 S / cm at a moisture content of less than 1% wt. In certain embodiments, the material has a specific surface area of about 200 m2 / g to about 500 m2 / g.

[0006] The materials of the subject disclosure can further include a doping agent. In certain embodiments, the doping agent selected from carboxylic acid, carboxylate anions, hydroxyl, sulfur-containing groups, carbonyl, phosphates, nitrates, polymer, nanoparticles, metal nanoparticles and combinations thereof.

[0007] The instantly disclosed materials can be used, for example, as a component of a heat sink, electronic device, transparent conductive film, touchscreen, solar cell, photodetector, fuel cell, electrolyzer, hydrocarbon compound, precast concrete, paint, battery cell or extraction and water treatment membrane.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0008] The foregoing summary, as well as the following detailed description of the exemplary embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments, which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.

[0009] In the drawings:

[0010] FIG. 1 depicts an exemplary synthesis scheme.

[0011] FIG. 2 depicts a plurality of exfoliated carbon nanotubes at a scale of 500 nm.

[0012] FIG. 3 A depicts SWCNTs, represented by the parallel lines, at 10 nm scale; at this magnification the SWCNTs are distinct and clear.

[0013] FIGS. 3B, 3C, 3D and 3E depicts a TEM characterizations of SWCNTs synthesized at the same time with GO and MWCNT, in which SWCNTs have been dispersed in water and deposited onto TEM grid for imaging; FIG. 3B depicts SWCNTs on the TEM GRID; FIG. 3C depicts TEM at low magnification; FIG. 3D depicts TEM at high magnification; and FIG. 3E depicts a bundled SWCNTs.

[0014] FIG. 4 depicts an exfoliation.

[0015] FIG. 5. depicts introducing CNT segments to N-doped fullerene caps.DETAILED DESCRIPTION OF THE INVENTION

[0016] Reference will now be made in detail to the various embodiments of the subject disclosure illustrated in the accompanying drawings. Wherever possible, the same or like reference numbers will be used throughout the drawings to refer to the same or like features. It should be noted that the drawings are in simplified form and are not drawn to precise scale. Certain terminology is used in the following description for convenience only and is not limiting. Directional terms such as top, bottom, left, right, above, below and diagonal, are used with respect to the accompanying drawings. The term “distal” shall mean away from the center of a body. The term “proximal” shall mean closer towards the center of a body and / or away from the “distal” end. The words “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of the identified element and designated parts thereof. Such directional terms used in conjunction with the following description of the drawings should not be construed to limit the scope of the subject disclosure in any manner not explicitly set forth. Additionally, the term “a,” as used in the specification, means “at least one.” The terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import.

[0017] “About” as used herein when referring to a measurable value such as an amount, a temporal duration, and the like, is meant to encompass variations of ±20%, ±10%, ±5%, ±1%, or ±0.1% from the specified value, as such variations are appropriate.

[0018] “Substantially” as used herein shall mean considerable in extent, largely but not wholly that which is specified, or an appropriate variation therefrom as is acceptable within the field of art. “Exemplary” as used herein shall mean serving as an example.

[0019] Throughout this disclosure, various aspects of the subject disclosure can be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the subject disclosure. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 2.7, 3, 4, 5, 5.3, and 6. This applies regardless of the breadth of the range.

[0020] Furthermore, the described features, advantages and characteristics of the exemplary embodiments of the subject disclosure may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize, in light of the description herein, that the present disclosure can be practiced without one or more of the specific features or advantages of a particular exemplary embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all exemplary embodiments of the subject disclosure.

[0021] The exfoliated carbon nanotubes of the subject disclosure offer advantages. The capped nanotubes (e.g., fullerene capped or fullertubes) remain in an organic and stable phase. But the derivatized carbon cage becomes increasingly hydrophilic and stronger, will undergo a change in solubility, and is removed with the aqueous phase in aseparatory funnel. It has strong resonance character and are dominated by two singlephonon bands, radial breathing mode and components of the G-mode In the present structure, these vibrations have modest intensity and resonance

[0022] The presently disclosed exfoliated nanotubes have better characterization of adsorption, self-assembly, and electronic structure, because of their electronic states show a certain resemblance to those of the extended nanotubes.

[0023] The exfoliated carbon nanotubes of the subject disclosure can be prepared based on utilization of exfoliation synthesis systems (i.e., a top -bottom approach) which results in production of the material at a high yield and prevention of re-agglomeration. This top-bottom synthesis is an epitaxial growth and employs liquid-phase exfoliation specifically for graphene synthesis.

[0024] A schematic is provided in FIG. 1 and discloses an exemplary method of making exfoliated hybrid graphene / carbon nanotubes having multiple walls and an outer diameter in the range of subnanometers to tens of nanometers, and having at least one end capped. The exemplary process makes use of megawatts power and megahertz frequency ultrasound. As shown in FIG. 1, organic activated carbon (e.g., organic activated carbon having 99% less 350 mesh) is subjected to dilute acid in deionized water Then it is doped with nitrogen to obtain hybrid graphene and multiple wall carbon nanotubes and then subjected to an ultrasonic-induced exfoliation under different acoustic intensity and cavitation mechanism to get many graphene-hybridized concentric carbon nanotube hybrid materials.

[0025] Nanotube exfoliation techniques known in the art can also be employed in conjunction with the above disclosure. See, e.g., U.S. Published Application No. 2011 / 0294013, which is hereby incorporated by reference.

[0026] FIGS. 2 and 3 depict a plurality of exfoliated carbon nanotubes at a nm scale.

[0027] FIG. 4 depicts a pre-final formation of fullertube formed by the exfoliation process. The composition of the pre-final formation comprises an un-ended graphene(shown as a beehive-like plate), fullerene (shown as a spherical cage) being molecules with carbon atoms, and a carbon nanotube (shown as a loose cylindrical shape) at the left part of the figure.

[0028] FIG. 5 depicts the CNTs Segment of which two ends to be cohesive to Fullerence Caps (at the left part of the figure), wherein the two adhere tightly to each other as cohesiveness by the doping agent with the ionic bond as a chemical bonding, which is different from that in general which is formed by the electricity activity. The FIG. 4 (at the right part) illustrates the finished synthesized product of the graphene-carbon nanotube according to the current invention as the form of N-doped Fullerene. Furthermore, the synthesis could be carried out repeatedly.

[0029] Fullertubes possess single-walled carbon nanotube belts resembling a rolled graphene midsection, but with half-fullerene end-caps. Unlike nanotubes, fullertubes are reproducible in structure, possess a defined molecular weight, and are soluble in pristine form.

[0030] It will be appreciated by those skilled in the art that changes could be made to the various aspects described above without departing from the broad inventive concept thereof. It is to be understood, therefore, that the subject application is not limited to the particular aspects disclosed, but it is intended to cover modifications within the spirit and scope of the subject application as defined by the appended claims.

Claims

CLAIMS1. A material comprising a plurality of exfoliated carbon nanotubes, each exfoliated carbon nanotube having multiple walls and an outer diameter in the range of subnanometers to tens of nanometers, and having at least one end capped.

2. The material of claim 1, wherein each exfoliated carbon nanotube is full length, preferably having a length of from about 0.2 pm to about 5 pm.

3. The material of any one of claims 1 or 2, wherein the outer diameter of each exfoliated carbon nanotube is from about 0.1 to about 10 nanometers.

4. The material of claim 3, wherein the outer diameter of the exfoliated carbon nanotubes is about 0.31 nanometers on average.

5. The material of any one of the preceding claims, wherein the at least one end is capped with half of a fullerene molecule.

6. The material of any one of the preceding claims, wherein each exfoliated carbon nanotube comprises from 5 to 10 concentric single-walled nanotubes.

7. The material of any one of the preceding claims, further comprising a doping agent selected from the group consisting of carboxylic acid, carboxylate anions, hydroxyl,sulfur-containing groups, carbonyl, phosphates, nitrates, polymer, nanoparticles, metal nanoparticles and combinations thereof.

8. The material of any one of the preceding claims combined in any proportion to form graphene -hybridized concentric carbon nanotube hybrid material.

9. The material according to any one of the preceding claims, wherein the material has a thickness of 0.18 nm to 5 nm and an apparent density lower than 0.03 g / cm3.

10. The material according to any one of the preceding claims, wherein the material has an electrical conductivity of 800 to 1200 S / cm at a moisture content of less than 1% wt.

11. The material according to any one of the preceding claims, wherein the material has a specific surface area of about 200 m2 / g to about 500 m2 / g.

12. Use of the material according to any one of the preceding claims as a component of a heat sink, electronic device, transparent conductive film, touchscreen, solar cell, photodetector, fuel cell, electrolyzer, hydrocarbon compound, precast concrete, paint, battery cell or extraction and water treatment membrane.

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