KR101548008B1 - Manufacturing method of polymer wrapped semiconducting carbon nanotube, polymer wrapped semiconducting carbon nanotube made by the same, and composition comprising polymer wrapped semiconducting carbon nanotube - Google Patents

Abstract

The present invention relates to a method for manufacturing a polymer wrapped semiconductive carbon nanotube, a polymer wrapped semiconductive carbon nanotube made by the same and a semiconductive carbon nanotube composition including the same and, more specifically, to a method for selectively wrapping a semiconductive carbon nanotube with a conjugated polymer, a polymer wrapped semiconductive carbon nanotube made by the same and a semiconductive carbon nanotube composition including the same. The conjugated polymer used in the method for manufacturing the polymer wrapped with the semiconductive carbon nanotube expresses a band gap, an HOMO and an LUMO energy level similar to band gap energy of the semiconductive carbon nanotube and includes a side chain with the length enough to wrap the semiconductive carbon nanotube, thereby having an effect of efficiently distributing a single-walled carbon nanotube having a semiconductive characteristic.

Description

TECHNICAL FIELD The present invention relates to a method for producing semiconducting carbon nanotubes wrapped with a polymer, a semiconducting carbon nanotube wrapped with the polymer produced thereby, and a semiconducting carbon nanotube composition containing the same. BACKGROUND ART [0002] NANOTUBE MADE BY THE SAME, AND COMPOSITION COMPRISING POLYMER WRAPPED SEMICONDUCTING CARBON NANOTUBE}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for producing semiconducting carbon nanotubes woven with polymers, a semiconducting carbon nanotube woven with the polymer produced thereby, and a semiconducting carbon nanotube composition containing the semiconducting carbon nanotubes. A method of selectively laminating a nanotube with a conjugated polymer, a semiconducting carbon nanotube lapped with the polymer produced thereby, and a semiconducting carbon nanotube composition containing the same.

Carbon nanotubes (CNTs) are carbon nanotubes (CNTs) that combine with other carbon atoms into hexagonal honeycomb patterns to form tubes. These carbon nanotubes are highly anisotropic and have a variety of structures such as single wall, multiwall, The diameter of the tube is nanometer (nm = one billionth of a meter), which is an extremely small area of material.

Carbon nanotubes have excellent mechanical properties, electrical selectivity, excellent field emission characteristics, and high-efficiency hydrogen storage media characteristics. Also, depending on the winding shape, it has the property of semiconductors, the energy gap varies according to the diameter, and it has a quasi one-dimensional structure and exhibits a unique quantum effect.

As the synthesis method, an electric discharge method, a thermal decomposition method, a laser deposition method, a plasma chemical vapor deposition method, a thermochemical vapor deposition method, and an electrolysis method are known. Carbon nanotubes also exhibit high electrical conductivity and are currently being used in the formation of conductive films and the like and may be used in the future for Field Emission Displays (FEDs) and probes of Scanning Probe Microscopes (SPMs) , And researches on it have been actively conducted. Current applications of carbon nanotubes include transparent electrodes, electrostatic dispersion films, field emission devices, surface heating elements, optoelectronics devices, and various sensors and transistors.

Carbon nanotubes have a nano-sized cylindrical shape with a graphite sheet and have an sp2 bond structure. The characteristics of the conductor or semiconductor are shown according to the angle and structure of the graphite surface. In addition, depending on the number of bonds forming the wall, single-walled carbon nanotubes (SWCNTs), double walled carbon nanotubes (DWCNTs), multi-walled carbon nanotubes (MWCNTs) ), And rope carbon nanotubes. In particular, single-walled carbon nanotubes exhibit various electrical, chemical, physical and optical characteristics due to their metallic and semiconducting properties, and by using these properties, more detailed and integrated devices can be realized.

However, despite the availability of such carbon nanotubes, the use of carbon nanotubes is limited due to their low solubility and low dispersibility. That is, carbon nanotubes can not stably disperse in an aqueous solution due to a strong van der Waals attractive force between them, and coagulation phenomenon occurs.

In order to solve such a problem, studies have been made on functionalization for modifying the surface of carbon nanotubes and imparting functionality, and one of them is noncovalent functionalization of carbon nanotubes.

The non-covalent functionalization of carbon nanotubes refers to hydrogen bond, van der Waals bond, charge transfer, dipole-dipole interaction, π-electron interaction (π- π stacking interaction, etc., to bind the substance to be modified on the surface of the carbon nanotube to impart a desired function. The non-covalent functionalization is advantageous in that functional groups can be imparted while maintaining the intrinsic properties of the tube, since there is no need to induce defects in the carbon nanotube structure. Non-covalent functionalization is usually carried out using surfactants, aromatic hydrocarbons, biomaterials, etc., and most carbon nanotubes are dispersed stably in an aqueous solution.

The method using aromatic hydrocarbons is one of the most studied methods among the non-covalent functionalization methods of the carbon nanotubes. The walls of the carbon nanotubes are made of hexagonal graphite structure, and can interact with molecules made of aromatic hydrocarbons such as conjugated polymers.

The conjugated polymer, which has an aromatic ring in the polymer chain, interacts with the wall of the nanotube and interacts with the nanotube. These conjugated polymers include PmPV (poly (metaphenylenevinylene)), PPE (poly (arylenethynylene)), PPvPV (poly {(2,6-pyridinylenevinylene) -co - [(2,5-dioctyloxy-pphenylene) Poly (p-phenylenevinylene), cisoidal PPA (polyphenylacetylene), transoidal PPA, and the like are known as poly (methyl methacrylate), PAmPV (poly (5-alkoxym-phenylenevinylene)

However, the conventional conjugated polymers have a problem that the nanotubes are not wrapped completely because of the high wrapping capability of the nanotubes.

In addition, a single layer (a structure mainly used for a quantum device application with a single walled carbon source) Because of the nature of the structure, the carbon nanotubes have a chirality (degree of arrangement of carbon atoms according to the axial direction of the carbon nanotube) Tubes and semiconducting carbon nanotubes. However, the two types of carbon nanotubes are mixed in the sample at the time of synthesis, and there is no technique for separating the two types of carbon nanotubes, which makes the application difficult. In particular, when carbon nanotubes are applied to transistors, only semiconducting carbon nanotubes are required. Therefore, in order to develop terabit semiconductors, it has been urgently required to develop a technique of extracting only a semiconductor carbon nanotube and extracting it in a large amount.

The present invention provides a method for fabricating polymer-wrapped semiconducting carbon nanotubes that can lap only semiconducting carbon nanotubes using a new polymer that is completely different from conventional conjugated polymers in order to overcome the problems of the related art as described above .

It is another object of the present invention to provide polymer-wrapped semiconducting carbon nanotubes produced by the method of the present invention and compositions containing the same.

The present invention has been made to solve the above problems

Mixing the conjugated polymer and the carbon nanotube in an organic solvent;

Ultrasonically treating the mixed solution;

Centrifuging the ultrasonic treated mixed solution; And

Separating the centrifuged sediment; The present invention also provides a method for producing a carbon nanotube.

In the method of producing a polymer-lapped carbon nanotube according to the present invention, the conjugated polymer has a band gap energy of 1.8 eV or less, a LUMO of 3.2 or more, and three peaks at a wavelength of 500 to 600 nm in an absorption spectrum . That is, in the method of producing a polymer-lapped carbon nanotube according to the present invention, the bandgap and HOMO and LUMO energy levels of the conjugated polymer are similar to carbon nanotubes.

In the method for producing a polymer-lapped carbon nanotube according to the present invention, the conjugated polymer has the following structure.

In the above formula, n is an integer of 1 to 10000.

In the method for producing a polymer-lapped carbon nanotube according to the present invention, the organic solvent is toluene.

In the method of manufacturing a polymer-lapped carbon nanotube according to the present invention, the carbon nanotube may be selected from the group consisting of a single-walled carbon nanotube, a double-walled carbon nanotube, a multi-walled carbon nanotube, And at least one kind thereof.

In the method of manufacturing a polymer-lapped carbon nanotube according to the present invention, the carbon nanotube is a semiconducting single-walled carbon nanotube. That is, the polymer-lapped carbon nanotube according to the present invention can selectively disperse only semiconducting single-walled carbon nanotubes.

In the method of manufacturing a polymer-lapped carbon nanotube according to the present invention, the carbon nanotube is performed at a centrifugation step of 40,000 g or more for 120 minutes to 180 minutes.

The present invention also provides polymer-lapped semiconducting carbon nanotubes prepared by the process for producing polymer-lapped carbon nanotubes according to the present invention and compositions comprising the same.

The conjugated polymer used in the method of producing a polymer-lapped semiconducting carbon nanotube according to the present invention exhibits a band gap and HOMO and LUMO energy levels similar to the band gap energy of the semiconducting carbon nanotube, Since it includes a side chain having a length sufficient for lapping, it exhibits an effect of efficiently dispersing single-walled carbon nanotubes having semiconductor characteristics.

Fig. 1 shows the result of measuring the absorbance after dispersing CoMoCat and HiPCO as single-walled carbon nanotubes in a 2% sodium cholate aqueous solution.
2 shows the result of measurement of an absorption spectrum of a solution in which conjugated polymer is dispersed in toluene.
3 is a schematic view illustrating a process of separating polymer-lined single-walled carbon nanotubes.
4 to 7 show the results of measuring the wrapping capability of the conjugated polymer.
FIG. 8 shows a result of measuring the absorbance of a film prepared using a solution containing a polymer-wrapped single-walled carbon nanotube according to an embodiment of the present invention.
FIGS. 9 and 10 are graphs showing results obtained by annealing a film prepared using a solution containing a polymer-wrapped single-walled carbon nanotube (HiPCO) prepared according to an embodiment of the present invention to remove the polymer and measuring the change in absorbance Results are shown.
FIG. 11 shows the results of measuring the absorbance of a single-walled carbon nanotube wrapped with a polymer prepared according to an embodiment of the present invention after forming a film on a metal surface.

Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited by the following examples.

Embodiments herein are described in connection with cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the embodiments. As is often said, variations from the form of example, for example, manufacturing techniques and / or tolerances are expected as a result. As such, embodiments should not be interpreted as being limited to the particular shapes of the regions illustrated herein, but include variations in shapes resulting from, for example, manufacture. Unless otherwise defined, all The term (including technical and scientific terms) has the same meaning as commonly understood by one of ordinary skill in the art to which the embodiment pertains. Terms such as those defined in commonly used dictionaries should be construed to have meanings consistent with their meanings in the context of the relevant field and shall not be construed as idealized or overly formal insofar as not expressly so defined herein .

< Example > 중합체 wrapped swCNT  Produce

< Example -1> SWNT

CoMoCat and HiPCO were prepared as single-walled carbon nanotubes. The dispersions of CoMoCat and HiPCO were dispersed in distilled water containing 2% sodium cholate surfactant as a dispersant, and the absorbance was measured. The results are shown in FIG. The m-SWNT peak appears in the blue portion of FIG. 1, indicating that both the metallic SWNT (m-SWNT) and the semiconducting SWNT (sc-SWNT) are present.

< Example -2> wrapping  Manufacture of Polymers

The conjugated polymers (rr-P3HT, PQTBTz-C12, and P8TBTz-C12) of the following compounds 1, 2 and 3 were prepared as a polymer for wrapping and the adsorption spectra of a solution in which the three polymers were dispersed in toluene ). The results are shown in Fig.

In FIG. 2, three peaks appear at a wavelength of 500 to 600 nm in the conjugated polymer 3 according to an embodiment of the present invention. Thus, the absorption spectra of Compound 1 (rr-P3HT) and Compound 2 (PQTBTz-C12) This is because compound 3 according to an embodiment of the present invention has a high bithiophene functional group and high side chain regioregularity. Particularly, the main peak near 550 nm is due to the bandgap of the conjugated polymer of Compound 3 according to the embodiment of the present invention, and the band gap is smaller than that of Compound 1 (rr-P3HT) and Compound 2 (PQTBTz-C12) .

In FIG. 2, the peak of the compound 1 (rr-P3HT) and the peak of the compound 2 (PQTBTz-C12) polymer appears at around 450 nm, but in the case of the conjugated polymer of Compound 3 according to the embodiment of the present invention, , Which is due to the bithiophene functional group, which is not substituted and serves to increase π-π stacking.

< Example -3> as a polymer wrapping  The swCNT  Produce

5 mg of the HiPCO or CoMoCat single-walled carbon nanotubes of Example-1 as the single-walled carbon nanotube and 10 mg of the three polymers of the compounds 1 to 3 of the Example-2 as the wrapping polymer were mixed and dispersed in toluene. In the case of sodium cholate, which is used as a dispersing agent in the prior art, since the single wall carbon nanotubes are prevented from being dispersed, toluene was used as a solvent instead of a colloidal salt such as chloroform and 1,2-dicholorobenzene.

The dispersion solvent was stored in a constant temperature cooling bath and ultrasonic wave was applied for 30 minutes at 70% to prepare single - walled carbon nanotubes wrapped with polymer. References to the wrapping process are as follows.

(1) Young-Jin Do, et al., Manipulating Electron Transfer Between Single-Walled Carbon Nanotubes and Diazonium Salts for High Purity Separation by Electronic Type, Chem. Mater. 24, 4146-4151 (2012)

(2) Hang Woo Lee, et al., Selective dispersion of high purity semiconducting single-walled carbon nanotubes with regioregular poly (3-alkylthiophene) s Nature. Commun., 2, 1-7 (2011)

(3) Do Hwan Kim, et al., Liquid-Crystalline Semiconducting Copolymers with Intramolecular Donor-Acceptor Building Blocks for High-Stability Polymer Transistors, JACS, 131, 6124-6132 (2009)

(4) Wenhui Yi, et al., Wrapping of Single-Walled Carbon Nanotubes by a Polymer: The Role of Polymer Conformation-Controlled Size Selectivity, J. Phys. Chem. B, 112, 12263-12269 (2008)

(5) Shenqiang Ren, et al., Toward Efficient Carbon Nanotube / P3HT Solar Cells: Active Layer Morphology, Electrical, and Optical Properties, Nano Lett. 11, 5316-5321 (2011)

(6) Hisashi Kokubo, et al., Synthesis of New Thiophene-Based Conjugated Polymers for Investigation of Molecular Alignment on the Surface of Platinum Plate, Macromolecules, 39, 3959-3963 (2006)

(7) Yosuke Kanal and Jeffrey C. Grossman, Role of Semiconducting and Metallic Tubes in P3HT / Carbon-Nanotube Photovoltaic Heterojunctions: Density Functional Theory Calculations, Nano Lett. 8, 908-912 (2008)

< Example -4> as a polymer wrapping  The Single wall  Separation of Carbon Nanotubes

The solution prepared in Example 3 was subjected to ultracentrifugation at 42,000 g for 150 minutes to remove single-walled carbon nanotube agglomerates and metallic single-walled carbon nanotubes and other impurities.

Figure 3 shows a schematic diagram of separation of polymer-wrapped swCNTs. As shown in FIG. 3, in the case of the present invention, supernatant and precipitate are separated by ultracentrifugation at 42,000 g. That is, in the case of a single-walled carbon nanotube wrapped by a polymer, In the case of single-walled carbon nanotubes not wrapped by polymers, they aggregate to each other and sink into the precipitate, while the soluble side chain of the polymer is well dispersed in the organic solvent.

EXPERIMENTAL EXAMPLE Wrapping of Compound 1 capability measurement

When single-walled carbon nanotubes are wrapped using rr-P3HT as the polymer prepared in Example 1 The wrapping capability was measured and the results are shown in FIG.

In FIG. 4, the case where the conjugated polymer and the single-walled carbon nanotube are simply mixed is shown as red line, and the case where the conjugated polymer and the single-walled carbon nanotube are mixed and centrifuged is shown as blue. In FIG. 4, when a polymer is mixed with a single-walled carbon nanotube (red line), peaks appear near 600 nm due to the π-π stacking between the polymer or polymer and the single-walled carbon nanotube. It can be seen that the tube-specific peak appears at 700 to 1400 nm. In addition, the intrinsic peak of the single-walled carbon nanotube becomes broader, and in the case of the peak due to the polymer, the peak is red-shifted by the single-walled carbon nanotube in comparison with the absorbance of the polymer itself shown in FIG. it can be seen that single-walled carbon nanotubes aggregate and are not separated as shown in FIG.

In contrast, in the case of the suspension obtained by performing the centrifugation, peaks due to π-π stacking and peaks due to single-walled carbon nanotubes do not appear in FIG. From this, it can be confirmed that the side chain length of the compound 1 (rr-P3HT) is not suitable because it does not sufficiently cover the single-walled carbon nanotubes.

EXPERIMENTAL EXAMPLE Wrapping of Compound 2 capability measurement

In the case of using Compound 2 having a longer side chain length than Compound 1 (rr-P3HT) as a polymer The wrapping capability was measured and the results are shown in FIG.

5, peaks due to the interaction between the polymer and the single-walled carbon nanotube and peaks inherent to the single-walled carbon nanotube are observed in the case of applying ultrasonic waves after the mixing, and the degree of polymerization using the polythiophene P3HT as the conjugated polymer 4, it can be seen that the intrinsic peak of single wall carbon nanotubes appears more clearly.

After centrifugation, the intrinsic peak intensity of SWNT was greatly decreased. When compound 2 was used as a polymer, SWNT was well dispersed but it was not well wrapped.

< Experimental Examples > Wrapping of Compound 3 capability measurement

When Compound 3 was used as a conjugated polymer and HiPCO was used as SWNT The wrapping capability was measured and the results are shown in FIG.

In FIG. 6, when a centrifuge was not performed (red line), the intrinsic peak of SWNT in the ultraviolet region and the intrinsic peak of SWNT in the infrared region appeared, and in the case of using Compound 3 as the polymer and HiPCO as the SWNT, Is formed, and it can be seen that a state of being well dispersed in the solvent is maintained.

In FIG. 6, impurities, single-walled carbon nanotube agglomerates, and single-walled carbon nanotube-unencapsulated polymers were all removed when centrifugation was performed in FIG. 6, revealing that a transparent pale purple solution was obtained. When the centrifugation was performed (blue line), no inherent peak of SWNT was observed, and it can be seen that SWNT was completely wrapped by the conjugated polymer represented by Compound 3.

In addition, an additional peak appears in the region of 400 to 600 nm, which is represented by the specific peak of the conjugated polymer represented by the compound 3, and a strong interaction between the conjugated polymer represented by the compound 3 and the SWNT acts.

The results of measuring the wrapping capability using CoMoCat as SWNT are shown in FIG. It can be seen that it is similar to the case of using HiPCO as SWNT.

< Example > With polymer wrapping  The swCNT Film Manufacturing

The film was prepared using the solution containing the single-walled carbon nanotubes wrapped with the conjugated polymer represented by the above-described compound 3, and the absorbance was measured. The results are shown in FIG.

In FIG. 8, the peak intensity and the position of the film are changed compared to the case of the solution state. However, it can be seen that the absorbance of the film state is similar to that of the solution state as a whole. Lt; RTI ID = 0.0 &gt; CNTs. &Lt; / RTI &gt;

< Example > Carbon Nanotube Dispersion Evaluation

The film prepared using the solution containing the single-walled carbon nanotube (HiPCO) wrapped with the conjugated polymer represented by the above-mentioned Compound 3 was annealed to remove the conjugated polymer, and the absorbance change was measured and shown in FIG.

In FIG. 9, the peak shape due to the single-walled carbon nanotubes wrapped with the conjugated polymer represented by the compound 3 changes in the region of 400 to 550 nm representing the metallic single-walled carbon nanotube, but the main peak in the region of 600 to 1400 nm is And the conjugated polymer represented by the compound 3 produced by the present invention can be selectively dispersed by wrapping the semiconducting single-walled carbon nanotubes.

The film prepared using the solution containing the single-walled carbon nanotube (CoMoCat) wrapped with the conjugated polymer represented by the compound 3 was annealed and the absorbance change was measured and shown in FIG. It can be seen in FIG. 10 that the position of the observation peak does not change even after the heat treatment.

< Example > Storage stability evaluation

A single-walled carbon nanotube wrapped with a conjugated polymer represented by Compound 3 was formed on a metal surface and the absorbance was measured. The results are shown in FIG.

Claims (9)

Mixing a conjugated polymer represented by the following chemical formula and a semiconducting single-walled carbon nanotube into an organic solvent;
Ultrasonically treating the mixed solution;
Centrifuging the ultrasonic treated mixed solution; And
Separating the centrifuged sediment; Wherein the carbon nanotube is lapped with a polymer.

In the above formula, n is an integer of 1 to 10000.
The method according to claim 1,
Wherein the conjugated polymer has a band gap energy of 1.8 eV or less and a LUMO of 3.2 or more.
delete The method according to claim 1,
Wherein the organic solvent is toluene, and a method for producing a polymer-lapped carbon nanotube
delete delete The method according to claim 1,
In the centrifugal separation step, is carried out at 40000 g or more for 120 minutes to 180 minutes.
A polymer-lapped carbon nanotube produced by the production method of any one of claims 1, 2, 4,
A composition comprising a polymer-lapped carbon nanotube according to claim 8

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