Thermoelectric elastomer and preparation method thereof

Abstract

The invention discloses a thermoelectric elastomer and a preparation method thereof, and relates to the technical field of organic thermoelectric material new energy. In the presence of a dopant and a cross-linking agent, a conjugated polymer and an elastomer material react in a solvent to obtain the thermoelectric elastomer. The thermoelectric elastomer prepared by the invention has the characteristics of high stretch rate, high strain recovery, high thermoelectric performance, low Young modulus and unique strain enhanced thermoelectric performance, and a thermoelectric integrated module based on the thermoelectric elastomer has excellent skin conformity, can accurately perceive the temperature change of a human body, generates electricity by utilizing the skin heat of the human body, and has the characteristics of high tensile strength, high strain recovery rate, high thermoelectric performance, low Young modulus and unique strain enhanced thermoelectric performance. And stable voltage output can be realized in thousands of stretching-releasing cycle processes. The preparation method has universality, and has good application prospects in the fields of organic electronics, wearable electronics, energy recovery and the like.

Description

Technical Field

[0001] The invention relates to the technical field of new energy of organic thermoelectric materials, and in particular to a thermoelectric elastomer and a preparation method thereof. Background Art

[0002] Energy is the material basis for the survival and development of human society. From the perspective of energy utilization efficiency, the current world energy utilization efficiency is less than 40%, and the remaining energy is mainly dissipated into the environment in the form of heat. In recent years, in view of the significant application prospects of flexible electronic devices in strategic emerging fields such as artificial intelligence, health monitoring and robotics, decentralized energy supply methods characterized by portability and wearability have begun to gain favor, and the collection and utilization of environmental heat and even human body heat are nurturing new energy industries. Therefore, achieving efficient application of thermal energy is an important way to alleviate current energy and environmental problems.

[0003] Thermoelectric conversion is a sustainable technology that uses thermoelectric materials to convert electrical energy and thermal energy, providing a simple and effective way to utilize waste heat and natural heat. Thermoelectric devices can use the "Seebeck effect" to convert thermal energy into electrical energy, and can also use the "Peltier effect" to reversely utilize electrical energy to produce a cooling effect. The use of these two effects to achieve the mutual conversion of "heat" and "electricity" has a wide range of applications in waste heat utilization and refrigeration. At the same time, thermoelectric materials can achieve thermoelectric conversion through the transmission and interaction of electrons and phonons, and will not produce mechanical movement to the environment, thereby achieving quiet operation in a pollution-free state. Therefore, thermoelectric devices based on thermoelectric materials are more able to utilize human body heat that is difficult to capture and convert due to its low-temperature characteristics, and will not cause harm to the human body and the environment. However, the structure of traditional thermoelectric devices is relatively rigid and cannot withstand mechanical stretching and extreme deformation, and it is difficult to meet the dynamic strain (5-50%) required for human movement; at the same time, traditional thermoelectric devices are difficult to directly attach to the surface of the heat source, and require the design of a special heat conduction part, which greatly reduces the thermoelectric conversion efficiency ((a) Jia, Y.; Jiang, Q.; Sun, H.; et al. Adv. Mater. 2021, 33, 2102990. (b) Han, S.; Liu, C.; Xi, H.; et al. npj Flex. Electron. 2018, 2, 16.). Skin-like thermoelectric devices prepared based on elastomeric polymer materials have the advantages of small size, light weight, easy integration, strong resistance to mechanical deformation, and can be closely attached to the surface of any complex shape of the human body and natural heat source. They can collect and utilize environmental waste heat and human body heat to generate electricity in real time and efficiently. However, the preparation of elastic thermoelectric materials and the processing technology of thermoelectric devices have not yet been reported and applied, which seriously limits the recovery and utilization of human body heat and environmental waste heat. Summary of the invention

[0004] The purpose of the present invention is to provide a thermoelectric elastomer and a preparation method thereof to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] One of the technical solutions of the present invention is to provide a method for preparing a thermoelectric elastomer, comprising the following steps:

[0007] In the presence of a dopant and a cross-linking agent, a conjugated polymer and an elastomeric material are reacted in a solvent to obtain the thermoelectric elastomer.

[0008] Furthermore, the difference in solubility parameters between the conjugated polymer and the elastomeric material is less than 6 MPa. 1 / 2 .

[0009] Furthermore, the mass ratio of the conjugated polymer to the elastomeric material is 1:9-9:1, more preferably 5:5-7:3.

[0010] Furthermore, the dopant is a thermally activated dopant, including (4-(1,3-dimethyl-2,3-dihydro-1H-benzimidazol-2-yl)phenyl)dimethylamine (N-DMBI). This type of dopant can be better dispersed in the conjugated polymer and elastomer blend system, and achieve the target doping of the dopant in the conjugated polymer-rich phase.

[0011] Furthermore, the amount of the dopant added is 5% to 50% of the mixed mass of the conjugated polymer / elastomeric polymer, preferably 15% to 25%.

[0012] Furthermore, the crosslinking agent is a diazoxide molecule, which can be decomposed into carbene under heating or ultraviolet light, and chemically crosslink the aliphatic side chains of the conjugated polymer and the elastomeric polymer by reacting with C(sp3)-H bonds.

[0013] Furthermore, the amount of the cross-linking agent added is 2% to 10% of the mixed mass of the conjugated polymer / elastomeric polymer, preferably 3% to 5%.

[0014] Furthermore, the solvent of the present invention is preferably chlorobenzene or chloroform.

[0015] The second technical solution of the present invention is to provide a thermoelectric elastomer prepared by the above preparation method.

[0016] The third technical solution of the present invention is to provide an elastic thermoelectric integrated module, which is prepared using the above-mentioned thermoelectric elastomer as a raw material.

[0017] The fourth technical solution of the present invention is to provide an elastic thermoelectric integrated module with a vertical structure, whose structure from bottom to top is an elastic substrate, an electrode, a thermoelectric elastic material, an electrode and an elastic substrate; wherein the thermoelectric elastic material is obtained by annealing the above-mentioned thermoelectric elastomer, and the annealing temperature is preferably 100-200°C.

[0018] The elastic substrate is made of an elastomeric polymer, including any one of polydimethylsiloxane (PDMS), hydrogenated styrene-butadiene block copolymer (SEBS), styrene-butadiene rubber (SBR), natural rubber (NR), ethylene-propylene rubber (EPR), butyl rubber (IIR) and thermoplastic polyurethane elastomer (PU).

[0019] Furthermore, the elastic substrate is preferably prepared by a drop coating method and has a thickness of 500 μm-3 mm.

[0020] Furthermore, the electrode is a gold electrode, more preferably a microcrack gold electrode; the thickness of the microcrack gold electrode is preferably 50-100 nm. In the present invention, the microcrack gold electrode can withstand mechanical deformation and can well maintain stable conductivity under tensile strain.

[0021] The thermoelectric elastic material is prepared from the above-mentioned thermoelectric elastomer by solution deposition method including drip coating, blade coating, rod coating and the like.

[0022] Furthermore, the thermoelectric elastic material is preferably columnar, and the column height is preferably 2-8 mm.

[0023] The elastic thermoelectric integrated module of the present invention can accurately sense changes in human body temperature, realize thermal electricity generation by human skin, has excellent skin conformity, and can output stable voltage during thousands of stretching-releasing cycles.

[0024] The method for preparing the elastic thermoelectric integrated module of the present invention specifically comprises the following steps:

[0025] (1) The elastic substrate and the thermoelectric elastic material are prepared on substrates respectively.

[0026] (2) preparing the microcrack gold electrode on the surface of the elastic substrate by a vacuum thermal evaporation method to obtain an elastic substrate with the microcrack gold electrode;

[0027] (3) Covering the elastic substrate with the electrode on the surface of the thermoelectric elastic material from the electrode side, transferring the thermoelectric elastic material to the elastic substrate with the electrode by thermal bonding, and then covering the surface of the thermoelectric elastic material from the electrode side with another elastic substrate with the electrode, thereby obtaining an elastic thermoelectric integrated module.

[0028] Furthermore, the vacuum thermal evaporation conditions are: the vacuum degree is 10 -4 ~10 -7 Pasla, preferably 4 to 8 × 10 -4 Pasla; evaporation rate is 1 to 10 angstroms / second, preferably 2 angstroms / second.

[0029] Furthermore, the heat bonding has a vacuum degree of 0.1-1 Pascal, a temperature of 50-80°C, and a time of 20 min-2 h.

[0030] In the above preparation steps of the present invention, the material of the substrate is any one of silicon wafer, glass, quartz and polytetrafluoroethylene.

[0031] Before use, the substrate is ultrasonically cleaned with detergent, deionized water, acetone, and ethanol in sequence, blown dry with a nitrogen gun, and then subjected to ultraviolet peroxidation (UVO) treatment to obtain a clean substrate; preferably, the ultrasonic conditions are: ultrasonic power of 10 to 100 watts, and ultrasonic time of 1 to 30 minutes.

[0032] More preferably, when preparing the elastic substrate, the concentration of the elastomeric polymer in the elastomeric polymer dispersion used is 200-300 mg / mL; when preparing the thermoelectric elastic material on the substrate, the above-mentioned thermoelectric elastomer dispersion is used for preparation, wherein the concentration of the thermoelectric elastomer is 5-15 mg / mL.

[0033] The elastic thermoelectric integrated module of the present invention can be closely attached to various parts of human skin, including elbows, wrists, knees, etc., and can generate electricity by utilizing the temperature difference between human skin and the environment, and can output a stable voltage during the deformation of human body parts.

[0034] The present invention realizes the formation of conjugated polymer nanofibers and their uniform dispersion in an elastomer matrix by selecting conjugated polymers and elastomeric polymers with similar solubility parameters, realizes crosslinking of the conjugated polymer and the elastomeric polymer by a crosslinking agent, and realizes targeted doping of the dopant in the conjugated polymer-rich phase by selecting a thermally activated dopant.

[0035] The thermoelectric elastomer material of the present invention is a polymer having high thermoelectric performance (thermoelectric figure of merit > 0.1), high stretchability (stretching rate > 100%), high elastic recovery rate (more than 90% recovery rate can be achieved under 150% tensile strain) and low elastic modulus (< 100 MPa).

[0036] The thermoelectric elastomer of the present invention is realized based on three strategies; the three strategies include: (1) using Hansen solubility parameters (HSPs) to predict the compatibility of conjugated polymers and insulating elastomers to achieve uniform multi-scale microphase separation morphology; (2) using heat-activated crosslinking agents to enhance the polymer network to improve the mechanical stretchability and elasticity of the thermoelectric elastomer; (3) selecting dopants that mainly diffuse into the conjugated polymer-rich phase for targeted doping to improve doping efficiency. Based on the above three strategies, the present invention realizes a thermoelectric elastomer material that has high stretchability, high strain recovery, high thermoelectric performance, low Young's modulus and unique strain-enhanced thermoelectric performance characteristics.

[0037] In the present invention, the uniform multi-scale microphase separation morphology requires that the conjugated polymer nanofibers are uniformly distributed inside the elastomeric polymer matrix.

[0038] In the present invention, the formation of uniform multi-scale microphase separation morphology of the conjugated polymer and the elastomeric polymer is predicted by the Hansen solubility parameter, and the solubility parameter difference is preferably <6MPa 1 / 2 .

[0039] In the present invention, the heat activated crosslinking agent reinforces the polymer network by simultaneously crosslinking the conjugated polymer nanoparticles and the elastomeric polymer.

[0040] The simultaneous cross-linking of the conjugated polymer nanofibers and the elastomeric polymer matrix is ​​achieved through the reaction of the sp3 hybridized carbon-hydrogen bonds (C(sp3)-H bonds) between the conjugated polymer and the elastomeric polymer molecular chain; the C(sp3)-H bond reaction between the conjugated polymer and the elastomeric polymer molecular chain is achieved through a bisdiazetidine cross-linking strategy.

[0041] The present invention discloses the following technical effects:

[0042] The present invention prepares a thermoelectric elastomer material that can withstand a tensile strain of >400%, a strain recovery rate of >90% (under 150% tensile strain), a low Young's modulus (<100MPa), a high thermoelectric figure of merit (>0.1) and enhanced strain-induced thermoelectric performance by optimizing the uniform multi-scale microphase separation morphology of conjugated polymers and elastomeric polymers in a blended film, achieving crosslinking of conjugated polymer nanofibers and an elastic polymer matrix, and achieving targeted doping of dopants in a conjugated polymer-rich phase.

[0043] The elastic thermoelectric integrated module prepared by using the thermoelectric elastomer material of the present invention has a simple preparation process, low cost, and can achieve large-area integration. The prepared thermoelectric integrated module has excellent skin conformity, can accurately sense changes in human body temperature, use human skin heat to generate electricity, and achieve stable voltage output during thousands of stretch-release cycles.

[0044] The method for preparing the thermoelectric elastomer and the elastic thermoelectric integrated module disclosed in the present invention is universal and has good application prospects in the fields of organic electronics, wearable electronics and energy recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 In the figure, A is a comparison of the solubility parameters of a commonly used elastomeric polymer and a conjugated polymer P (PzDPP-2FT); B is a comparison of the solubility parameters of a commonly used elastomeric polymer and a conjugated polymer P (gTDPP-BT).

[0047] Figure 2 These are atomic force microscope (AFM) morphology images of the thermoelectric elastomer films prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 of the present invention.

[0048] Figure 3 It is the elastic modulus of the thermoelectric elastomer film prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 of the present invention.

[0049] Figure 4 1 and 2 are stress-strain curves of the thermoelectric elastomer films prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 of the present invention, wherein A is Example 1 and Comparative Example 1, and B is Example 2 and Comparative Example 2.

[0050] Figure 5 In which, A is the energy loss rate of the thermoelectric elastomer film prepared in Example 1 of the present invention and Comparative Example 1 under a tensile strain of 0-150%, and B is the strain recovery rate of the thermoelectric elastomer film prepared in Example 1 of the present invention under a tensile strain of 0-150%.

[0051] Figure 6 The figure is a comparison of the electrical conductivity, power factor and thermoelectric figure of merit of the thermoelectric elastomers prepared by Example 1, Example 2, Comparative Example 1 and Comparative Example 2 of the present invention, wherein A is Example 1 and Comparative Example 1, and B is Example 2 and Comparative Example 2.

[0052] Figure 7 The conductivity change rate and power factor change rate of the thermoelectric elastomer film prepared in Example 1 of the present invention under different tensile strains.

[0053] Figure 8In the figure, A and B are respectively the output voltage and output power of the thermoelectric elastomer film prepared in Example 1 of the present invention in an unstretched state; C and D are respectively the output voltage and output power of the thermoelectric elastomer film prepared in Example 1 of the present invention after being stretched and released 1000 times at 25% strain.

[0054] Fig. 9 This is a flow chart of the elastic thermoelectric integrated module prepared in Example 1 of the present invention.

[0055] Fig.10 This is a schematic diagram of the structure of the elastic thermoelectric integrated module prepared in Example 1 of the present invention.

[0056] Fig.11 In the figure, A is a physical picture of the elastic thermoelectric integrated module prepared in Example 1 of the present invention tightly attached to the surface of the deformed elbow to realize thermal electricity generation by human skin; B is a physical picture of the elastic thermoelectric integrated module prepared in Example 2 of the present invention tightly attached to the surface of the deformed wrist to realize thermal electricity generation by human skin. DETAILED DESCRIPTION

[0057] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0058] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0059] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0060] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0061] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0062] Example 1

[0063] This embodiment provides a method for preparing a thermoelectric elastomer material, the steps are as follows:

[0064] (1) 70 mg of a conjugated polymer (pyrazine-diketopyrrolopyrrole-3,4-difluorothiophene) (P(PzDPP-2FT)) and 30 mg of an elastomer hydrogenated styrene-butadiene block copolymer (SEBS) were weighed and added to a chlorobenzene solvent at a blending concentration of 30 mg / mL to obtain a mixed solution.

[0065] (2) Weigh 20 mg of dopant N-DMBI and add it to the mixed solution obtained in step (1).

[0066] (3) Weigh 5 mg of a bisdiazetidine crosslinker and add it to the mixed solution obtained in step (2) to obtain a P(PzDPP-2FT) / SEBS / N-DMBI / crosslinker chlorobenzene solution.

[0067] (4) P(PzDPP-2FT) / SEBS / N-DMBI / crosslinking agent chlorobenzene solution (concentration of 30 mg / mL) was mixed at 50°C and 500 rpm for 1 hour to uniformly blend the components to obtain a uniformly blended solution of the thermoelectric elastomer material.

[0068] (5) Drying the uniformly blended solution of the thermoelectric elastomer material prepared in step (4) at room temperature for 12 h, and then drying it in a drying oven at 120° C. for 1 h to obtain a thermoelectric elastomer material.

[0069] Mechanical properties test of the thermoelectric elastomer prepared in Example 1:

[0070] 1 mL of the uniformly blended solution of the thermoelectric elastomer material prepared in step (4) of Example 1 was extracted with a syringe and added dropwise into a polytetrafluoroethylene groove (length / width / height=3:0.5:2 cm), then dried at room temperature for 12 hours, and then dried in a 120° C. drying oven for 1 hour. Finally, the prepared thermoelectric elastomer film was taken out of the groove with sharp tweezers to obtain a thermoelectric elastomer film with a thickness of 0.6 mm.

[0071] Thermoelectric performance test of the thermoelectric elastomer prepared in Example 1:

[0072] A 0.8 cm × 0.5 cm clean silicon wafer was placed at the center of the rotor of the coating machine, and 30 μL of the uniformly blended solution of the thermoelectric elastomer material prepared in step (4) of Example 1 was drawn with a 200 μL pipette and evenly dropped on the silicon wafer, and the coating machine was started and maintained at a speed of 2000 rpm / min for 1 min. Finally, the silicon wafer was removed and placed on a hot plate at 120° C. for annealing for 30 min, and a thermoelectric elastomer film with a thickness of 70 nm for thermoelectric performance testing was obtained.

[0073] Thermoelectric conversion efficiency test of the thermoelectric elastomer prepared in Example 1:

[0074] First, a thermoelectric elastomer column is prepared. The uniform blended solution of the thermoelectric elastomer material prepared in step (4) of Example 1 is continuously dripped into a polytetrafluoroethylene groove with a length, width, and height of 5 cm, 0.5 cm, and 2 mm, respectively. The mixture is placed at room temperature for 5 hours, and then heated on a hot plate at 120°C for 1 hour to obtain a thermoelectric elastomer column with a height of 2 mm.

[0075] Secondly, a 5cm×5cm clean glass sheet was placed on a hot stage, and 1.5mL of hydrogenated styrene-butadiene block copolymer (SEBS) toluene solution (concentration of 150mg / mL) was slowly drawn with a 2mL syringe and evenly dropped on the glass sheet, and then kept at 40°C for 2 hours and then at 90°C for 1 hour to obtain a stretchable substrate (elastic substrate) with a thickness of 0.1mm. Note: In order to ensure that there are no bubbles in the prepared stretchable substrate and good surface uniformity, the drop rate should be as slow as possible, and the last two drops of SEBS toluene solution should not be dropped on the silicon wafer.

[0076] Then, the elastomer SEBS substrate was peeled off with tweezers, and micro-crack gold electrodes were directly prepared on the surface of the SEBS substrate by vacuum evaporation. The vacuum thermal evaporation conditions were: vacuum degree 10 -5 Pasla, evaporation rate is 2 Å / s, thickness of microcracked gold electrode is 50 nm.

[0077] Finally, the SEBS substrate with microcrack gold electrode is gently covered on the surface of the thermoelectric elastomer column from the side of the microcrack electrode, and the thermoelectric elastomer column is transferred to the SEBS substrate with microcrack gold electrode by thermal bonding. Similarly, another identical SEBS substrate with microcrack gold electrode is covered on the surface of the thermoelectric elastomer column from the side of the microcrack gold electrode, and the microcrack gold electrode and the thermoelectric elastomer column are bonded by thermal bonding to obtain an elastic thermoelectric integrated module. The thermal bonding process is carried out in a vacuum drying oven, and the thermal bonding conditions are: vacuum degree of 0.1 Pascal, heating treatment temperature of 60°C, and heating treatment time of 20 minutes.

[0078] Fig. 9This is a flow chart of the elastic thermoelectric integrated module prepared in Example 1 of the present invention. Fig.10 This is a schematic diagram of the structure of the elastic thermoelectric integrated module prepared in Example 1 of the present invention.

[0079] Example 2

[0080] This embodiment provides a preparation method of a thermoelectric elastomer material, and the steps are as follows:

[0081] (1) 70 mg of a conjugated polymer 9,9'-diphenyl-9,9-di(trifluoromethyl)-fullerene derivative-benzothiadiazole conjugated polymer (P(gTDPP-BT)) and 30 mg of an elastomer itaconate rubber (IBR) were weighed and added to a chloroform solvent at a blending concentration of 30 mg / mL to obtain a blending solution.

[0082] (2) Weigh 5 mg of dopant N-DMBI and add it to the mixed solution obtained in step (1).

[0083] (3) Weigh 3 mg of the bisdiazetidine crosslinker and add it to the mixed solution obtained in step (2) to obtain a P(gTDPP-BT) / IBR / N-DMBI / crosslinker chloroform solution.

[0084] (4) P(gTDPP-BT) / IBR / N-DMBI / cross-linking agent chloroform solution (30 mg / mL) was mixed at 50°C and 500 rpm for 1 hour to uniformly blend the components to obtain a uniformly blended solution of the thermoelectric elastomer material.

[0085] (5) Drying the uniformly blended solution of the thermoelectric elastomer material prepared in step (4) at room temperature for 12 h, and then drying it in a drying oven at 120° C. for 1 h to obtain a thermoelectric elastomer material.

[0086] The corresponding samples were prepared in the same manner as in Example 1, and the mechanical properties, thermoelectric conversion efficiency, and thermoelectric performance of the thermoelectric elastomer material were measured.

[0087] Comparative Example 1

[0088] A preparation method of a thermoelectric elastomer material comprises the following steps:

[0089] (1) 100 mg of conjugated polymer (pyrazine-diketopyrrolopyrrole-3,4-difluorothiophene) (P(PzDPP-2FT)) was weighed and added to chlorobenzene solvent at a concentration of 30 mg / mL to obtain a P(PzDPP-2FT) chlorobenzene solution.

[0090] (2) Weigh 20 mg of dopant N-DMBI and add it to the above P(PzDPP-2FT) chlorobenzene solution to obtain a P(PzDPP-2FT) / N-DMBI chlorobenzene solution.

[0091] (3) Weigh 5 mg of a bisdiazetidine crosslinker and add it to the solution obtained in step (2) to obtain a P(PzDPP-2FT) / N-DMBI / crosslinker chloroform solution.

[0092] (4) The P(PzDPP-2FT) / N-DMBI / crosslinking agent chlorobenzene solution obtained in step (3) was mixed at 50° C. and 800 rpm for 1 hour to obtain a uniform blend solution of the thermoelectric elastomer material.

[0093] (5) Drying the uniformly blended solution of the thermoelectric elastomer material prepared in step (4) at room temperature for 12 h, and then drying it in a drying oven at 120° C. for 1 h to obtain a thermoelectric elastomer material.

[0094] The corresponding samples were prepared in the same manner as in Example 1, and the mechanical properties, thermoelectric conversion efficiency, and thermoelectric performance of the thermoelectric elastomer material were measured.

[0095] Comparative Example 2

[0096] A preparation method of a thermoelectric elastomer material comprises the following steps:

[0097] (1) 100 mg of conjugated polymer 9,9'-diphenyl-9,9-di(trifluoromethyl)-fullerene derivative-benzothiadiazole conjugated polymer (P(gTDPP-BT)) was weighed and added to chloroform solvent at a concentration of 30 mg / mL to obtain a P(gTDPP-BT) chloroform solution.

[0098] (2) Weigh 5 mg of dopant N-DMBI and add it to the P(gTDPP-BT) chloroform solution in step (1) to obtain a P(gTDPP-BT) / N-DMBI chlorobenzene solution.

[0099] (3) Weigh 3 mg of the bisdiazetidine crosslinker and add it to the solution obtained in step (2) to obtain a P(gTDPP-BT) / N-DMBI / crosslinker chloroform solution.

[0100] (4) The chlorobenzene solution of P(gTDPP-BT) / N-DMBI / cross-linking agent was mixed at 50° C. and 500 rpm for 1 hour to obtain a uniform blend solution of the thermoelectric elastomer material.

[0101] (5) Drying the uniformly blended solution of the thermoelectric elastomer material prepared in step (4) at room temperature for 12 h, and then drying it in a drying oven at 120° C. for 1 h to obtain a thermoelectric elastomer material.

[0102] The corresponding samples were prepared in the same manner as in Example 1, and the mechanical properties, thermoelectric conversion efficiency, and thermoelectric performance of the thermoelectric elastomer material were measured.

[0103] Figure 1 The solubility parameters of the elastomeric polymer and the conjugated polymer are compared. According to the principle of solubility parameter proximity, Example 1 of the present invention selected the elastomer SEBS with a solubility parameter close to that of the conjugated polymer P (PzDPP-FT), and the difference in solubility parameters between the two is 5.93 MPa. 1 / 2 Example 2 selected the elastomer IBR with a solubility parameter similar to that of the conjugated polymer P (gTDPP-BT), and the difference in solubility parameters between the two was 3.01 MPa 1 / 2 Comparative Example 1 is a P(PzDPP-FT) / N-DMBI blend without adding an elastomer; Comparative Example 2 is a P(gTDPP-BT) / N-DMBI blend without adding an elastomer.

[0104] Figure 2 The AFM morphology images of the thermoelectric elastomer films of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 of the present invention are shown. Compared with Comparative Example 1 and Comparative Example 2, the thermoelectric elastomer films prepared in Example 1 and Example 2 exhibit obvious conjugated polymer nanofiber morphology, indicating that the introduction of the elastomeric polymer can promote the formation of conjugated polymer nanofibers, which is beneficial to the transport of carriers and the improvement of stretchability.

[0105] Figure 3 and Figure 4 The elastic modulus and stress-strain curves of the thermoelectric elastomer films of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 of the present invention are shown in FIG. Figure 3 and Figure 4 It can be seen that, compared with the thermoelectric elastomer without adding the elastomer (Comparative Example 1 and Comparative Example 2), the addition of the elastomer can significantly reduce the elastic modulus of the thermoelectric elastomer and increase the tensile strain of the thermoelectric elastomer (>400%).

[0106] Taking Example 1 and Comparative Example 1 as examples, the strain recovery capabilities are analyzed in detail:

[0107] Figure 5 In the figure, A is the energy loss rate of the thermoelectric elastomer film prepared in Example 1 of the present invention and Comparative Example 1 under 0-150% tensile strain, and B is the strain recovery rate of the thermoelectric elastomer film prepared in Example 1 of the present invention under 0-150% tensile strain. Figure 5As shown, the thermoelectric elastomer film prepared in Comparative Example 1 has an energy loss rate of >75% under 15% tensile strain, while the thermoelectric elastomer film prepared in Example 1 only exhibits an energy loss rate of <45% and a strain recovery rate of 90% under 0% to 150% tensile strain. This indicates that the thermoelectric elastomer prepared in the present invention has very excellent strain tolerance and strain recovery.

[0108] like Figure 6 As shown, compared with Comparative Examples 1 and 2, the thermoelectric elastomer films prepared in Examples 1 and 2 exhibit significantly increased conductivity and power factor and reduced thermal conductivity. Therefore, selecting an elastomer polymer with a solubility parameter similar to that of the conjugated polymer can significantly improve its thermoelectric performance.

[0109] Figure 7 It is shown that the electrical conductivity and power factor of the thermoelectric elastomer prepared in Example 1 of the present invention gradually increase to 400% and 300% with the increase of tensile strain; when the strain reaches about 80%, these properties begin to decrease; but under a tensile strain of 150%, its thermoelectric performance is still higher than that of the unstretched state.

[0110] Figure 8 In the figure, A and B are the output voltage and output power of the thermoelectric elastomer film prepared in Example 1 of the present invention in the unstretched state; C and D are the output voltage and output power of the thermoelectric elastomer film prepared in Example 1 of the present invention after being stretched and released 1000 times at 25% strain. Figure 8 It can be seen that the output power of the thermoelectric elastomer prepared in Example 1 of the present invention after being stretched and released 1000 times at 25% strain is only reduced by about 20% compared with the unstretched state, and the output power can still be maintained above 100nW.

[0111] Fig. 9 and Fig.10 They are respectively a flow chart and a structural schematic diagram of the elastic thermoelectric integrated module prepared by the present invention. Fig.11 In the figure, A is a physical picture of the elastic thermoelectric integrated module prepared in Example 1 of the present invention tightly attached to the surface of the deformed elbow to realize the thermal electricity generation of human skin; B is a physical picture of the elastic thermoelectric integrated module prepared in Example 2 of the present invention tightly attached to the surface of the deformed wrist to realize the thermal electricity generation of human skin. Fig.11 As shown, when attached to a deformed elbow or wrist of a human body, the elastic thermoelectric integrated modules prepared in Examples 1 and 2 can exhibit an output voltage of more than 1 mV.

[0112] The elastic thermoelectric integrated module prepared based on thermoelectric elastomer materials in the present invention has excellent skin conformity, resistance to extreme deformation, can accurately sense changes in human body temperature and realize thermal electricity generation from human skin. At the same time, the method provided by the present invention has simple process and low cost, and can be prepared on a large scale for a variety of organic semiconductor material systems, broadening its application prospects in the fields of organic electronics, wearable electronics and energy recovery.

[0113] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing a thermoelectric elastomer, characterized in that: The following steps are involved: In the presence of a dopant and a cross-linking agent, a conjugated polymer and an elastomeric material are reacted in a solvent to obtain the thermoelectric elastomer.

2. The preparation method according to claim 1, characterized in that: The difference in solubility parameters between the conjugated polymer and the elastomeric material is less than 6 MPa 1 / 2 .

3. The preparation method according to claim 1, characterized in that: The mass ratio of the conjugated polymer to the elastomeric material is 1:9-9:

1.

4. The preparation method according to claim 1, characterized in that: The added amount of the dopant is 5-50% of the total mass of the conjugated polymer and the elastomeric material; the added amount of the crosslinking agent is 2-10% of the total mass of the conjugated polymer and the elastomeric material.

5. The preparation method according to claim 1, characterized in that: The dopant includes (4-(1,3-dimethyl-2,3-dihydro-1H-benzimidazol-2-yl)phenyl)dimethylamine.

6. Thermoelectric elastomer prepared by the preparation method according to any one of claims 1 to 5.

7. An elastic thermoelectric integrated module, characterized in that: The thermoelectric elastomer according to claim 6 is used as a raw material for preparation.

8. An elastic thermoelectric integrated module, characterized in that: The structure from bottom to top is an elastic substrate, an electrode, a thermoelectric elastic material, an electrode and an elastic substrate; the thermoelectric elastic material is obtained by annealing the thermoelectric elastomer described in claim 6.

9. The elastic thermoelectric integrated module according to claim 8, characterized in that: The elastic substrate material includes any one of polydimethylsiloxane, hydrogenated styrene-butadiene block copolymer, styrene-butadiene rubber, natural rubber, ethylene-propylene rubber, butyl rubber and thermoplastic polyurethane elastomer.

10. The method for preparing the elastic thermoelectric integrated module according to claim 8 or 9, characterized in that: The following steps are involved: (1) preparing the elastic substrate and the thermoelectric elastic material respectively; (2) preparing the electrode on the surface of the elastic substrate by a vacuum thermal evaporation method to obtain an elastic substrate with the electrode; (3) Covering the elastic substrate with the electrode on the surface of the thermoelectric elastic material from the electrode side, transferring the thermoelectric elastic material to the elastic substrate with the electrode by thermal bonding, and then covering the surface of the thermoelectric elastic material from the electrode side with another elastic substrate with the electrode, thereby obtaining the elastic thermoelectric integrated module.

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