CN111799361A - Liquid crystal carbon nanotube composite thermoelectric material and preparation method thereof - Google Patents
Liquid crystal carbon nanotube composite thermoelectric material and preparation method thereof Download PDFInfo
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- H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
- H10N10/80—Constructional details
- H10N10/85—Thermoelectric active materials
- H10N10/856—Thermoelectric active materials comprising organic compositions
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
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- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
- H10N10/80—Constructional details
- H10N10/85—Thermoelectric active materials
- H10N10/851—Thermoelectric active materials comprising inorganic compositions
- H10N10/855—Thermoelectric active materials comprising inorganic compositions comprising compounds containing boron, carbon, oxygen or nitrogen
Abstract
The invention discloses a liquid crystal carbon nanotube composite thermoelectric material and a preparation method thereof, wherein the composite thermoelectric material comprises: the liquid crystal display comprises discotic liquid crystal molecules and single-arm carbon nanotubes, wherein the discotic liquid crystal molecules are attached to the single-arm carbon nanotubes; the discotic liquid crystal molecules consist of discotic cores and a plurality of side chains connected with the peripheries of the discotic cores, and the structural general formula of the discotic liquid crystal molecules is as follows:
wherein the disk-shaped core is a polycyclic aromatic hydrocarbon and the side isThe chain is an alkyl side chain. The composite thermoelectric material provided by the invention has high Seebeck coefficient, high conductivity and high power factor, and also has good flexibility and certain mechanical property, so that the novel liquid crystal/carbon nanotube composite thermoelectric material is expected to be applied to flexible wearable thermoelectric equipment. Compared with the traditional inorganic thermoelectric material, the preparation method is simple and easy to realize, low in cost and easy to process and form.
Description
Technical Field
The invention relates to the technical field of thermoelectric materials, in particular to a composite thermoelectric material and a preparation method thereof.
Background
At present, about two thirds of energy of fossil fuel, which is a main energy source, is dissipated as waste heat in the actual use process, and the utilization efficiency of energy can be improved by secondary utilization of waste heat. The thermoelectric device can realize the direct interconversion of heat energy and electric energy, has the advantages of less pollution, no noise, no mechanical loss and the like, and is an ideal environment-friendly energy conversion device. The thermoelectric material is a semiconductor functional material which realizes the interconversion between heat energy and electric energy by utilizing the movement of carriers in a solid, and mainly comprises three basic physical phenomena: the Seebeck effect (temperature difference creates an electric field), the Peltier effect (electric field drives carrier absorption/release through the heterojunction interface), and the Thomson effect (describes the heating and cooling process of a current-carrying conductor with a temperature gradient). These three effects constitute a complete system describing the physical effect of direct conversion of thermoelectric energy. The energy-saving device has the advantages of small volume, light weight, quiet running, no need of conversion media and mechanical movable parts and the like, and is widely concerned as a novel energy material.
The performance of the thermoelectric material is determined by the dimensionless thermoelectric figure of merit ZT ═ S2And sigma T/kappa, wherein S is the Seebeck coefficient of the material, sigma is the electric conductivity, T is the thermodynamic absolute temperature, and kappa is the thermal conductivity. The larger the ZT value is, the higher the thermoelectric conversion efficiency is, the more excellent the performance of the thermoelectric material is, so that an excellent thermoelectric material must have a high Seebeck coefficient and a high electric conductivity (usually S2σ is called Power Factor (PF) and low thermal conductivity. Three important parameters S, sigma and k for determining the thermoelectric performance of the material are closely related, and the increase or decrease of one parameter alone often causes the non-synergistic change of the other parameters, which is that the thermoelectric performance ZT is difficult to holdThe root cause of the improvement continues. Therefore, the realization of independent or cooperative regulation and control of electricity and heat transport is a long-sought goal in the field of thermoelectric material science.
Thermoelectric materials are largely classified into inorganic thermoelectric materials and organic thermoelectric materials. In recent years, inorganic thermoelectric materials such as PbTe, GeTe and Bi have rapidly developed2Te3And Sb2Te3And the like, all obtained certain research results. However, these materials suffer from the disadvantages of extremely high manufacturing cost, low resources, difficult processing, toxicity, etc., and thus have greatly limited their large-scale commercial application in thermoelectric energy conversion. Compared with inorganic thermoelectric materials, the organic thermoelectric materials have the outstanding advantages of rich resources, low price, easy synthesis, easy processing, low thermal conductivity and the like, and show good development potential in the field of thermoelectric materials. In addition, thermoelectric devices made of organic thermoelectric materials have the advantages of being light, flexible, non-toxic, wearable and the like, and have great potential in applications such as power generation in remote areas (for example, military field deployment) and power supply for small mobile wireless devices requiring low power consumption (for example, health sensors of athletes or emergency response personnel). However, the thermoelectric performance of the intrinsic state is too poor, which severely limits the further development of the organic thermoelectric material. The single-arm carbon nanotube (SWCNT) has larger specific surface area and conjugated pi-pi structure, has excellent electrical conductivity and good mechanical property, is mixed with an organic thermoelectric material (polymer or micromolecule) to form a composite material, shows the dual advantages of low thermal conductivity of an organic phase and high electrical conductivity of an inorganic phase, and is a novel thermoelectric material which is researched more and developed more rapidly in recent years. However, the thermoelectric performance is still further improved compared to conventional inorganic thermoelectric materials.
Therefore, the development of new organic materials in composite materials is one of the most direct and effective approaches to addressing their lower thermoelectric performance.
Disclosure of Invention
In view of the above-mentioned shortcomings of the prior art, the present invention aims to provide a composite thermoelectric material and a method for preparing the same, which aims to solve the problem of low thermoelectric performance of the conventional composite thermoelectric material based on carbon nanotubes.
The technical scheme of the invention is as follows:
a composite thermoelectric material, wherein the composite thermoelectric material comprises: the liquid crystal display comprises discotic liquid crystal molecules and single-arm carbon nanotubes, wherein the discotic liquid crystal molecules are attached to the single-arm carbon nanotubes;
the discotic liquid crystal molecules consist of discotic cores and a plurality of side chains connected with the peripheries of the discotic cores, and the structural general formula of the discotic liquid crystal molecules is as follows:
wherein the disk-shaped core is polycyclic aromatic hydrocarbon, and the side chain is an alkyl side chain.
Optionally, the fused ring aromatic hydrocarbon is selected from one of the following structural formulas:
alternatively, the alkyl side chain has the general molecular formula-CnH2n+1Wherein the value of n is 6-20;
the alkyl side chain is directly attached to the disk-shaped core; alternatively, the alkyl side chain is linked to the discotic nucleus by an ether linkage, a thioether linkage, an ester linkage, an amide linkage.
Optionally, in the composite thermoelectric material, the mass ratio of the discotic liquid crystal molecules to the single-arm carbon nanotubes is (1-9): 10.
the invention relates to a preparation method of a composite thermoelectric material, which comprises the following steps:
dispersing the single-arm carbon nano tube in an organic solvent, and uniformly stirring to obtain a single-arm carbon nano tube solution;
adding discotic liquid crystal molecules into the single-arm carbon nanotube solution, and uniformly stirring to obtain a mixed solution;
and (3) placing the mixed solution on a substrate, and naturally airing to obtain the composite thermoelectric material.
Optionally, the organic solvent is one or more of chlorobenzene, dichlorobenzene, toluene, tetrahydrofuran and chloroform.
Optionally, in the step of dispersing the single-arm carbon nanotubes in the organic solvent and uniformly stirring, the stirring is ultrasonic stirring, and the ultrasonic stirring time is 3 to 12 hours.
Optionally, in the mixed solution, the mass of the discotic liquid crystal molecules is 10-90% of the mass of the single-arm carbon nanotubes.
Optionally, the step of taking the mixed solution on a substrate includes: taking 100 mu L of the mixed solution and placing the mixed solution in an area of 1 multiplied by 1cm2Or 1.5X 1.5cm2On the substrate.
Optionally, the substrate is a glass substrate.
Has the advantages that: the invention provides a novel composite thermoelectric material based on the composition of discotic liquid crystal molecules and single-arm carbon nanotubes. The composite thermoelectric material has high power factor, good flexibility and certain mechanical property, so that the organic thermoelectric thin film material is expected to be applied to flexible wearable thermoelectric equipment. Compared with the traditional inorganic thermoelectric material, the preparation method of the composite thermoelectric material is simple, easy to realize, low in cost and easy to machine and form.
Drawings
FIG. 1 is a schematic structural diagram of a discotic liquid crystal molecule HAT6 according to an embodiment of the present invention;
FIG. 2 is a POM (polarizing microscope) diagram of a discotic liquid crystal molecule HAT6 in an embodiment of the present invention;
FIG. 3 is a DSC (differential thermal analyzer) diagram of the discotic liquid-crystal molecule HAT6 in the specific example of the present invention;
fig. 4 is a raman spectrum of a composite thermoelectric material in which discotic liquid crystal molecules are composited with single-arm carbon nanotubes according to an embodiment of the present invention, wherein the composite thermoelectric material is a thin film made of a composite material with different composite ratios (SWCNT/HAT6 ═ 1:0.25,1:0.5,1:1,1:4) and a pure carbon nanotube thin film;
fig. 5 is XRD (X-ray diffraction) patterns of a composite thermoelectric material in which discotic liquid crystal molecules are composited with one-arm carbon nanotubes according to different composite ratios (SWCNT/HAT6 ═ 1:0.25,1:0.5,1:1,1:4) and a pure carbon nanotube film in an embodiment of the present invention;
FIGS. 6a to 6d are SEM (scanning Electron microscope) images of the surface of a thin film made of the composite thermoelectric material with the composite ratio of the single-arm carbon nanotube to the discotic liquid crystal molecule being 1:0.25,1:0.5,1:1, and 1:4, respectively, according to an embodiment of the present invention;
FIG. 7 is a Seebeck coefficient diagram of a composite thermoelectric material prepared by combining discotic liquid crystal molecules with single-arm carbon nanotubes according to different combination ratios (SWCNT/HAT6 is 1:0.25,1:0.5,1:1,1:4) and a pure carbon nanotube film at room temperature (300k) in an embodiment of the present invention;
fig. 8 is a graph of the electrical conductivity of the composite thermoelectric material of the discotic liquid crystal molecules and the single-arm carbon nanotubes in different composite ratios (SWCNT/HAT6 ═ 1:0.25,1:0.5,1:1,1:4) at room temperature (300k) for the thin film and the pure carbon nanotube thin film in the embodiment of the present invention;
fig. 9 is a graph of power factors of thin films made of composite thermoelectric materials in which discotic liquid crystal molecules are composited with single-arm carbon nanotubes at different composite ratios (SWCNT/HAT6 ═ 1:0.25,1:0.5,1:1,1:4) and pure carbon nanotube thin films at room temperature (300k) in an embodiment of the present invention.
Detailed Description
The present invention provides a composite thermoelectric material and a method for preparing the same, and the present invention will be described in further detail below in order to make the objects, technical solutions, and effects of the present invention clearer and clearer. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Specifically, a thermoelectric material with excellent performance needs to have a large Seebeck coefficient and high electrical conductivity and low thermal conductivity, however, since the existing inorganic thermoelectric material has high thermal conductivity and the organic thermoelectric material has low electrical conductivity, the thermoelectric performance of the simple inorganic or organic thermoelectric material is poor. The organic/inorganic composite thermoelectric material can combine the dual advantages of high electric conductivity of inorganic materials and high Seebeck coefficient and low thermal conductivity of organic materials, and obtains excellent thermoelectric performance.
The inventors have found that discotic liquid crystalline molecules are generally composed of a planar rigid aromatic core with peripheral alkyl side chains. The aromatic central nuclei are stacked into a column by self-assembly due to strong pi-pi interaction, and a rapid channel is provided for the transmission of carriers. The peripheral alkyl side chain can increase the solubility of molecules and provide an external insulating environment for a transmission channel of a carrier. The discotic liquid crystal molecules have strong self-assembly performance, stable structure and order, excellent photoelectric property and remarkable low-cost processability, so that the discotic liquid crystal molecules become an ideal organic semiconductor material, and have wide application prospects in Organic Field Effect Transistors (OFETs), Organic Light Emitting Diodes (OLEDs) and organic photovoltaic devices (OPVs). To date, no document or patent reports the application of the discotic liquid crystal small molecule/carbon nanotube composite material in the thermoelectric field.
The inventor further researches and discovers that a large aromatic fused ring nucleus in a discotic liquid crystal molecule is sp2Hybridization, likewise, the carbon atom in the one-armed carbon nanotube is sp2The same hybridization orbit is more beneficial to pi-pi interaction between the discotic liquid crystal molecules and the single-arm carbon nano tubes, and simultaneously, the discotic liquid crystal molecules have strong self-assembly and charge transmission capacity, so that the composite material based on the discotic liquid crystal molecules and the single-arm carbon nano tubes has higher electric conductivity and Seebeck coefficient, and further obtains high Power Factor (PF), and meanwhile, the thermal conductivity of the composite thermoelectric material after being compounded is reduced, so that excellent thermoelectric performance is obtained.
Specifically, an embodiment of the present invention provides a composite thermoelectric material, wherein the composite thermoelectric material includes: the liquid crystal display comprises discotic liquid crystal molecules and single-arm carbon nanotubes, wherein the discotic liquid crystal molecules are attached to the single-arm carbon nanotubes;
the discotic liquid crystal molecules consist of discotic cores and a plurality of side chains connected with the peripheries of the discotic cores, and the structural general formula of the discotic liquid crystal molecules is as follows:
wherein the disk-shaped core is polycyclic aromatic hydrocarbon, and the side chain is an alkyl side chain.
The embodiment of the invention provides a novel composite thermoelectric material obtained by compounding discotic liquid crystal molecules and single-arm carbon nanotubes, wherein the discotic liquid crystal molecules are attached to the single-wall carbon nanotubes. The composite thermoelectric material has high power factor, good flexibility and certain mechanical property, so that the organic thermoelectric thin film material is expected to be applied to flexible wearable thermoelectric equipment. Compared with the traditional inorganic thermoelectric material, the preparation method of the composite thermoelectric material provided by the embodiment of the invention is simple, easy to realize, low in cost and easy to machine and form.
The discotic liquid crystal molecule of the embodiment of the invention has a discotic core with a plane or an approximate plane at the center of the molecule, and a plurality of flexible side chains are connected to the periphery of the core, wherein the side chains are alkyl side chains, the side chains can be the same or different, and the side chains can be 4, 6 or 8. The discotic liquid crystal molecules have a distinct ordered state between liquid and crystalline states, i.e., a liquid crystal state, which has both liquid-like mobility and crystal-like anisotropy.
In one embodiment, the fused ring aromatic hydrocarbon is selected from one of the following structural formulas:
namely, the polycyclic aromatic hydrocarbon is one of the polycyclic aromatic hydrocarbons such as benzophenanthrene, azabenzophenanthrene, dibenzoperylene, hexabenzocoronene and the like.
In one embodiment, the alkyl side chain has the general molecular formula-CnH2n+1Wherein the value of n is 6-20;
the alkyl side chain is directly attached to the disk-shaped core; alternatively, the alkyl side chain is linked to the discotic nucleus by an ether linkage, a thioether linkage, an ester linkage, an amide linkage.
In one embodiment, in the composite thermoelectric material, the mass ratio of the discotic liquid crystal molecules to the single-arm carbon nanotubes is (1-9): 10.
the embodiment of the invention provides a preparation method of the composite thermoelectric material, which comprises the following steps:
s10, dispersing the single-arm carbon nano tube in an organic solvent, and uniformly stirring to obtain a single-arm carbon nano tube solution;
s20, adding discotic liquid crystal molecules into the single-arm carbon nanotube solution, and uniformly stirring to obtain a mixed solution;
and S30, placing the mixed solution on a substrate, and naturally airing to obtain the composite thermoelectric material.
In step S10, the single-arm carbon nanotubes are dispersed in an organic solvent, and stirred until the single-arm carbon nanotubes become pasty and are uniformly dispersed, thereby obtaining a single-arm carbon nanotube solution.
In one embodiment, the organic solvent is one or more of chlorobenzene, dichlorobenzene, toluene, tetrahydrofuran, chloroform, and the like.
In one embodiment, the agitation is ultrasonic agitation for a period of 3 to 12 hours.
In step S20, in one embodiment, ultrasonic agitation is used until the discotic liquid crystal molecules are uniformly dispersed.
In one embodiment, the mass of the discotic liquid crystal molecules in the mixed solution is 10 to 90% of the mass of the one-armed carbon nanotube.
In step S30, in an embodiment, a pipette is used to take the mixed solution on a substrate with a certain area, and the mixed solution is naturally dried to obtain the composite thermoelectric material in which discotic liquid crystal molecules and single-arm carbon nanotubes are composited.
In one embodiment, the step of taking the mixed solution on a substrate includes: taking 100 mu L of the mixed solution and placing the mixed solution in an area of 1 multiplied by 1cm2Or 1.5X 1.5cm2On the substrate.
In one embodiment, the substrate is a glass substrate or the like, but is not limited thereto.
The invention is further illustrated by the following specific examples.
Example 1
The discotic liquid crystal molecule is HAT6, the structural formula of which is shown in fig. 1, which is purchased from Synthon chemicals gmbh & co.kg, and the characterization method comprises the following steps:
(1) carrying out polarization microscope test on the discotic liquid crystal molecules HAT6 to obtain a liquid crystal phase texture;
(2) and carrying out differential scanning calorimetry test on the discotic liquid crystal molecules HAT6 to obtain the liquid crystal phase range of the discotic liquid crystal molecules HAT 6.
Example 2
The preparation method of the SWCNT/HAT6 composite thermoelectric material comprises the following steps:
placing 5mg of single-arm carbon nano-tube and 5mL of chlorobenzene in a 10mL glass bottle, and placing the glass bottle in an ultrasonic machine for ultrasonic treatment for about 3 hours to finally uniformly disperse the single-arm carbon nano-tube in a pasty state. Then, the discotic liquid crystal molecule HAT6 in example 1 was weighed according to the mass ratio of the single-walled carbon nanotube (SWCNT) to the discotic liquid crystal molecule HAT6 of 1:0.25,1:0.5,1:1,1:4, that is, the compound HAT6 was weighed to have the mass of 1.25mg, 2.5mg, 5mg and 20mg, respectively, and added to a glass bottle of the uniformly dispersed single-walled carbon nanotube solution. And putting the glass bottle into the ultrasonic machine again, and continuing to perform ultrasonic treatment until discotic liquid crystal molecules are uniformly dispersed to obtain a mixed solution. Finally, 250. mu.L of the uniformly dispersed mixed solution was applied to a washed glass plate (1.5X 1.5 cm) by means of a pipette gun2) And naturally airing to obtain the tube composite thermoelectric material for the thermoelectric test.
Example 3
Characterization of the performance of discotic liquid crystal molecules HAT6, performance characterization and thermoelectric performance testing of SWCNT/HAT6 composite thermoelectric materials and p-type pure single-walled carbon nanotube materials:
1. the liquid crystal molecules HAT6 pass Zeiss polarizing microscope test, and as a result, a clear liquid crystal texture can be seen as shown in FIG. 2.
2. The liquid crystal molecules HAT6 passed the test of a differential thermal analyzer (model DSC-Q200, manufactured by TA of USA) and the liquid crystal phase range is 67.72-98.82 ℃ as shown in FIG. 3.
3. Four SWCNT/HAT6 composite thermoelectric materials and pure single-arm carbon nanotube films in different ratios were examined by laser confocal raman spectroscopy (model invia, manufactured by Renidhaw, uk). The detected laser light source was 514.5 nm. The raman spectra of four SWCNT/HAT6 composite thermoelectric materials in different ratios and a pure single-arm carbon nanotube film are shown in fig. 4. The G peak and D peak of the composite thermoelectric material added with discotic liquid crystal molecules HAT6 hardly changed in shift, indicating that the added HAT6 did not destroy the original SWCNT structure. The strength in the RBM (radial breathing mode) band of the SWCNT/HAT6 composite thermoelectric material is reduced, which indicates that the discotic liquid crystal molecules HAT6 and SWCNT are well combined. The Raman spectrum characteristics of the composite thermoelectric material are consistent with the thermoelectric data result at normal temperature.
4. Four different ratios of SWCNT/HAT6 composite thermoelectric materials and pure one-armed carbon nanotube films were tested by Bruker D8Advance X-ray diffractometer and the XRD results are shown in fig. 5. The SWCNT/HAT6 composite thermoelectric material shows a diffraction peak profile similar to that of discotic liquid crystal molecule HAT6, the peak value of the SWCNT/HAT6 composite thermoelectric material slightly shifts to a large angle direction, which indicates that strong interaction occurs between the SWCNT/HAT6 composite thermoelectric material and the discotic liquid crystal molecule HAT6 composite thermoelectric material, and is beneficial to improving the Seebeck coefficient of the composite thermoelectric material, but excessive HAT6 breaks the interpenetrating network structure of a pure carbon tube, and the conductivity of the composite thermoelectric material is reduced. This is consistent with the thermoelectric results observed for the SWCNT/HAT6 composite thermoelectric material.
5. The surface of the composite thermoelectric materials with different composite ratios was magnified and scanned by a Hitachi SU-70 field emission scanning electron microscope, and the results are shown in FIGS. 6a to 6 d. It is evident that compound HAT6 is attached as white granular crystals to the network of single-walled carbon nanotubes and its number and size increase with increasing composite ratio.
6. Thermoelectric performance tests were performed on the SWCNT/HAT6 composite thermoelectric materials of different composite ratios by a garton MRS-3 thin film thermoelectric test system, and the results are shown in fig. 7 to 9. Compared with a pure carbon tube, the Seebeck coefficient of the composite thermoelectric material at room temperature is improved by more than one time, and the change of the Seebeck coefficient along with the content of HAT6 is not large; and the conductivity decreases significantly with increasing HAT6 content. Therefore, the power factor of the composite thermoelectric material reaches the highest value when the mass ratio of SWCNT/HAT6 is 1:0.25, and is 408 mu Wm-1K-2。
In summary, compared with the traditional inorganic thermoelectric material, the novel liquid crystal/carbon nanotube composite thermoelectric material provided by the invention has higher Seebeck coefficient, electrical conductivity and power factor, and also has good flexibility and certain mechanical property, so that the novel liquid crystal/carbon nanotube composite thermoelectric material is expected to be applied to flexible wearable thermoelectric equipment. Compared with the traditional inorganic thermoelectric material, the preparation method is simple and easy to realize, low in cost and easy to process and form.
It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.
Claims (10)
1. A composite thermoelectric material, comprising: the liquid crystal display comprises discotic liquid crystal molecules and single-arm carbon nanotubes, wherein the discotic liquid crystal molecules are attached to the single-arm carbon nanotubes;
the discotic liquid crystal molecules consist of discotic cores and a plurality of side chains connected with the peripheries of the discotic cores, and the structural general formula of the discotic liquid crystal molecules is as follows:
wherein the disk-shaped core is polycyclic aromatic hydrocarbon, and the side chain is an alkyl side chain.
2. The composite thermoelectric material of claim 1, wherein the fused ring aromatic hydrocarbon is selected from one of the following structural formulas:
3. the composite thermoelectric material of claim 1, wherein the alkyl side chain has the general molecular formula-CnH2n+1Wherein the value of n is 6-20;
the alkyl side chain is directly attached to the disk-shaped core; alternatively, the alkyl side chain is linked to the discotic nucleus by an ether linkage, a thioether linkage, an ester linkage, an amide linkage.
4. The composite thermoelectric material according to claim 1, wherein the mass ratio of the discotic liquid crystal molecules to the one-armed carbon nanotubes in the composite thermoelectric material is (1-9): 10.
5. a method of making a composite thermoelectric material of any of claims 1 to 4, comprising the steps of:
dispersing the single-arm carbon nano tube in an organic solvent, and uniformly stirring to obtain a single-arm carbon nano tube solution;
adding discotic liquid crystal molecules into the single-arm carbon nanotube solution, and uniformly stirring to obtain a mixed solution;
and (3) placing the mixed solution on a substrate, and naturally airing to obtain the composite thermoelectric material.
6. The method for preparing a composite thermoelectric material according to claim 5, wherein the organic solvent is one or more of chlorobenzene, dichlorobenzene, toluene, tetrahydrofuran, and chloroform.
7. The method for preparing a composite thermoelectric material according to claim 5, wherein in the step of dispersing the single-arm carbon nanotubes in the organic solvent and uniformly stirring, the stirring is ultrasonic stirring, and the ultrasonic stirring is performed for 3 to 12 hours.
8. The method for producing a composite thermoelectric material according to claim 5, wherein the mass of the discotic liquid crystal molecules in the mixed solution is 10 to 90% of the mass of the one-armed carbon nanotube.
9. The method of claim 5, wherein the step of applying the mixed solution to the substrate comprises: taking 100 mu L of the mixed solution and placing the mixed solution in an area of 1 multiplied by 1cm2Or 1.5X 1.5cm2On the substrate.
10. The method of producing a composite thermoelectric material according to claim 5, wherein the substrate is a glass substrate.
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