Polyethylene dioxythiophene-based fiber thermoelectric material, preparation method and application thereof

Abstract

The present invention relates to a polyethylene dioxythiophene-based fiber thermoelectric material, a preparation method and an application thereof, and belongs to the technical field of organic thermoelectric materials. The preparation method of the polyethylene dioxythiophene-based fiber thermoelectric material provided by the present invention comprises the following steps: (1) ultrasonically cleaning and drying the hygroscopic fiber; (2) soaking the hygroscopic fiber in a Nafion solution and an EDOT solution successively, so that Nafion and EDOT are successively adsorbed on the hygroscopic fiber; (3) soaking the fiber obtained in step (2) in an aqueous solution of ferric chloride, and rotating the obtained fiber in the aqueous solution of ferric chloride for 5min-120min under heating conditions to obtain the polyethylene dioxythiophene-based fiber thermoelectric material. The preparation method of the present invention can achieve the firm attachment of PEDOT on the fiber, and can also achieve mass production under the condition of uniform distribution of PEDOT.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic thermoelectric materials, and particularly relates to a polyethylenedioxythiophene-based fiber thermoelectric material, a preparation method thereof, and an application thereof. Background Art

[0002] Thermoelectric materials can achieve direct conversion between thermal energy and electrical energy, and have incomparable advantages in recovering human body waste heat and industrial waste heat. Organic flexible thermoelectric materials have unique advantages in self-powered systems of wearable electronic devices and utilization of human body waste heat due to their flexibility and good thermoelectric properties. Therefore, the preparation of organic flexible thermoelectric materials and device design have attracted extensive attention of researchers. Among them, polyethylenedioxythiophene (PEDOT) is a polymer of 3,4-ethylenedioxythiophene (EDOT), which has a high electrical conductivity. In the doped case, it can be used instead of metal materials, and has a low manufacturing cost and good stability, and is one of the most potential organic thermoelectric materials among many polymers. The fiber-based flexible PEDOT thermoelectric materials and devices have the characteristics of three-dimensional deformability, light weight, and good flexibility, and are very suitable for use in wearable or mobile electronic systems.

[0003] The performance of thermoelectric materials is measured by the dimensionless thermoelectric figure of merit ZT = (σ·S 2 ·T) / κ, where σ is the electrical conductivity of the material, S is the Seebeck coefficient of the material, κ is the thermal conductivity, and T is the absolute temperature. The improvement of thermoelectric performance is generally achieved by increasing the power factor (σ·S 2 ) and reducing the thermal conductivity. Research shows that the power factor of PEDOT can be optimized by adjusting its structure and morphology. The relationship between the Seebeck coefficient and conductivity of PEDOT and its morphology is as follows: PEDOT bulk < PEDOT particles < PEDOT microspheres < PEDOT rods < PEDOT fibers (Journal of Materials Chemistry A 2015, 3(42), 20896 - 20902). Therefore, fibrous PEDOT can achieve a higher power factor, and thus has a higher thermoelectric figure of merit.

[0004] During the preparation of PEDOT on a template or other carriers, there will be a problem of poor adhesion, and at the same time, there will be partial shedding during use. In addition, the preparation of PEDOT on carriers is still in the small-scale stage at present, and large-scale preparation will cause problems such as uneven distribution of PEDOT and large performance differences. Therefore, it is of great significance to prepare a PEDOT material that can be mass-produced and has high stability. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problems existing in the above-mentioned prior art and to provide a polyethylene dioxythiophene-based fiber thermoelectric material, a preparation method and an application thereof.

[0006] The present invention is achieved through the following technical solutions:

[0007] The present invention provides a method for preparing a polyethylene dioxythiophene-based fiber thermoelectric material, comprising the following steps:

[0008] (1) ultrasonically cleaning and drying the hygroscopic fiber;

[0009] (2) soaking the hygroscopic fiber in a Nafion solution and an EDOT solution successively, so that the Nafion and EDOT are successively adsorbed onto the hygroscopic fiber;

[0010] (3) Soaking the fiber obtained in step (2) in an aqueous solution of ferric chloride, and rotating the obtained fiber in the aqueous solution of ferric chloride for 5 min to 120 min under heating conditions to obtain the polyethylene dioxythiophene-based fiber thermoelectric material.

[0011] Nafion is a perfluorosulfonic acid polymer, the molecular chain structure is composed of a hydrophobic fluorocarbon skeleton and a hydrophilic ionized sulfonic acid group, has good ionic conductivity, and is often used as an adhesive in electrochemistry. The preparation method of the present invention uses Nafion as an adhesive to achieve the firm adhesion of PEDOT to the hygroscopic fiber. At the same time, Nafion can also be used as a dopant for PEDOT to dope PEDOT. The schematic diagram of the interaction between Nafion and PEDOT is shown in the figure. Figure 1 As shown. The preparation method of the present invention is prepared by rotating the fiber adsorbed with Nafion and EDOT in an aqueous solution of ferric chloride, so as to achieve the purpose of uniformly distributing PEDOT on the fiber. And the fiber rotates in the solution, and under the action of the rotating shear force, the structure of the synthesized PEDOT presents a fiber-like shape and has higher conductivity. The present invention uses hygroscopic fiber as a carrier for the synthesis of PEDOT, applies green and renewable cellulose materials to the field of thermoelectric materials, and the obtained polyethylene dioxythiophene-based fiber thermoelectric material has excellent thermoelectric properties.

[0012] Preferably, in step (3), the reaction time is 30 min-60 min; more preferably, the reaction time is 40 min-50 min.

[0013] As a preferred embodiment of the method for preparing the polyethylene dioxythiophene-based fiber thermoelectric material of the present invention, the diameter of the hygroscopic fiber is 0.01 mm-5 mm, and the length is 5 cm-10 m.

[0014] The present invention uses natural or artificial fibers with certain hygroscopicity as the synthetic carrier of PEDOT. There is no special restriction on the fiber type of the hygroscopic fiber. Preferably, the hygroscopic fiber can be at least one of natural or artificial fibers such as silk, wool, cotton, polyester fiber, etc.

[0015] Preferably, in step (1), the diameter of the hygroscopic fiber is 100 μm-1000 μm, and the length is 15 cm-100 cm. More preferably, the diameter of the hygroscopic fiber is 200 μm-600 μm, and the length is 15 cm-50 cm. Preferably, the hygroscopic fiber is cotton thread.

[0016] As a preferred embodiment of the method for preparing the polyethylene dioxythiophene-based fiber thermoelectric material of the present invention, in the step (2), the concentration of the Nafion solution is 4wt%-6wt%; and the purity of the EDOT solution is not less than 99%.

[0017] Preferably, in step (2), the concentration of the Nafion solution is 5 wt %; and the purity of the EDOT solution is 99%.

[0018] As a preferred embodiment of the method for preparing the polyethylene dioxythiophene-based fiber thermoelectric material of the present invention, in the step (2), the hygroscopic fiber is immersed in the Nafion solution for no more than 1800 seconds, and the hygroscopic fiber is immersed in the EDOT solution for no more than 300 seconds.

[0019] Specifically, the operation of step (2) may be: immersing the hygroscopic fiber in Nafion solution and EDOT solution successively, taking it out, and scraping and clamping it with tweezers to make Nafion and EDOT adsorbed onto the hygroscopic fiber successively; the scraping and clamping are performed no more than 30 times.

[0020] On the one hand, multiple scraping and clamping can make Nafion better enter the interior of the fiber and be evenly distributed; on the other hand, it can remove excess Nafion on the fiber surface, allowing the EDOT soaked in the next step to enter the fiber more.

[0021] Preferably, in the step (2), the soaking time of the hygroscopic fiber in the Nafion solution is 5s-20s, the soaking time of the hygroscopic fiber in the EDOT solution is 10s-120s, and the number of scraping and clamping is 1-10 times. More preferably, the soaking time of the hygroscopic fiber in the Nafion solution is 5s-10s, the soaking time of the hygroscopic fiber in the EDOT solution is 20s-60s, and the number of scraping and clamping is 2-5 times.

[0022] As a preferred embodiment of the method for preparing the polyethylene dioxythiophene-based fiber thermoelectric material of the present invention, in the step (3), the concentration of the ferric chloride aqueous solution is 0.1 mol / L-3 mol / L.

[0023] Preferably, in step (3), the concentration of the aqueous ferric chloride solution is 0.5 mol / L-1.5 mol / L; more preferably, the concentration of the aqueous ferric chloride solution is 1 mol / L-1.5 mol / L.

[0024] As a preferred embodiment of the method for preparing the polyethylene dioxythiophene-based fiber thermoelectric material of the present invention, in the step (3), the heating temperature is 20°C-80°C.

[0025] Preferably, in step (3), the heating temperature is 40°C-55°C; more preferably, the heating temperature is 45°C-50°C.

[0026] As a preferred embodiment of the method for preparing the polyethylene dioxythiophene-based fiber thermoelectric material of the present invention, in the step (3), the rotation adopts a rotating compass, the rotating compass includes a disk and a rotating rod, the rotating rod is arranged below the disk, the rotating rod and the disk are connected by inlaying, and a groove is chiseled at the bottom end of the rotating rod; the rotating compass is connected to a motor, and the fiber is rotated by being wound around the rotating rod.

[0027] The present invention winds the adsorbent fiber in the solution on a rotating rod and rotates it, so that the fiber rotates in a direction parallel to the rotation. Through the action of shear force, fibrous PEDOT can be synthesized. If the fiber is rotated perpendicular to the rotation direction, the obtained PEDOT is spherical particles instead of fibers.

[0028] Specifically, the operation of step (3) is as follows: winding the fiber obtained in step (2) into the groove on the rotating rod of the rotating compass, completely immersing the fiber in the FeCl3 solution, and under heating conditions, using a motor to drive the compass to rotate the fiber in the FeCl3 solution to obtain the polyethylene dioxythiophene-based fiber thermoelectric material. The voltage of the motor does not exceed 5V. Preferably, the voltage of the motor is 0.5V-2V; more preferably, the voltage of the motor is 0.5V-1V.

[0029] As a preferred embodiment of the method for preparing the polyethylene dioxythiophene-based fiber thermoelectric material of the present invention, at least one of the following conditions is met:

[0030] (a) In step (1), the ultrasonic cleaning is performed by ultrasonic cleaning with water and ethanol respectively, and the ultrasonic cleaning time is 5 min to 30 min;

[0031] (b) In step (1), the drying temperature is 30°C-100°C and the drying time is 0.5h-12h;

[0032] (c) In step (3), the rotation speed does not exceed 32 rpm.

[0033] Preferably, in step (1), the ultrasonic cleaning is performed using secondary water and ethanol respectively, and the ultrasonic time in the secondary water and ethanol is 10 min-20 min.

[0034] Preferably, in step (1), the drying temperature is 40°C-100°C, and the drying time is 0.5h-6h; more preferably, the drying temperature is 40°C-60°C, and the drying time is 2h-3h.

[0035] Preferably, in step (3), the rotation speed is 4 rpm-16 rpm; more preferably, the rotation speed is 4 rpm-8 rpm.

[0036] Another object of the present invention is to provide a polyethylene dioxythiophene-based fiber thermoelectric material prepared by the method for preparing the polyethylene dioxythiophene-based fiber thermoelectric material as described above.

[0037] The PEDOT in the polyethylene dioxythiophene-based fiber thermoelectric material prepared by the present invention has a fiber-like structure and good thermoelectric performance. In addition, the fiber is used as a carrier to apply green and renewable cellulose materials to the field of thermoelectric materials, which is of great significance to improving resource utilization and the development of new materials.

[0038] Another object of the present invention is to provide application of the polyethylene dioxythiophene-based fiber thermoelectric material in conductive materials and thermoelectric materials.

[0039] The present invention has the following beneficial effects:

[0040] (1) The preparation method of the present invention can achieve the firm attachment of PEDOT on the fiber, and can also carry out mass production of PEDOT under the condition of uniform distribution of PEDOT. In addition, the present invention prepares the fiber adsorbed with EDOT and Nafion by rotating it in an aqueous solution of ferric chloride, so that PEDOT is evenly distributed on the fiber. The fiber rotates in the solution, and under the action of the rotating shear force, the structure of the synthesized PEDOT presents a fiber-like shape, and has higher conductivity.

[0041] (2) The present invention uses hygroscopic fibers as carriers for the synthesis of PEDOT. The fibers are hygroscopic and have better adsorption capacity, and can better adsorb Nafion and EDOT. Nafion is used as an adhesive to achieve firm adhesion of PEDOT to the cotton fiber. At the same time, Nafion is used as a dopant for PEDOT, and PEDOT is doped, so that the polyethylene dioxythiophene-based fiber thermoelectric material obtained by the present invention has a higher conductivity and Seebeck coefficient, and the thermoelectric performance is significantly improved.

[0042] (3) The present invention applies green and renewable cellulose materials to the field of thermoelectric materials, which is of great significance to improving resource utilization and the development of new materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagram of the interaction between Nafion and PEDOT;

[0044] Figure 2 is a schematic diagram of a rotating compass used in the embodiments and comparative examples;

[0045] Figure 3 This is the SEM image of the polyethylene dioxythiophene-based fiber thermoelectric material of Example 1. DETAILED DESCRIPTION

[0046] To better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. It should be understood by those skilled in the art that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0047] Unless otherwise specified, the experimental methods used in the examples are all conventional methods; the materials, reagents, etc. used, unless otherwise specified, can be obtained from commercial channels.

[0048] Example 1

[0049] A method for preparing a polyethylene dioxythiophene-based fiber thermoelectric material comprises the following steps:

[0050] (1) A cotton fiber with a length of 30 cm and a cross-sectional diameter of 300 μm was cut and placed in a beaker. It was ultrasonicated in secondary water and ethanol for 10 min each, and then placed in an oven at 50 °C for 2 h to dry;

[0051] (2) Immerse the cotton fiber in a 5 wt% Nafion solution for 10 seconds, then take it out and scrape it with tweezers three times; then immerse the cotton fiber in 99% pure EDOT for 30 seconds, then take it out and scrape it with tweezers three times;

[0052] (3) Wind the cotton thread fiber obtained in step (2) into Figure 2 In the groove on the rod of the rotating turntable shown; Figure 2 The rotating compass shown includes a disc and 8 rotating rods, the rotating rods are arranged below the disc, the rotating rods are connected to the disc by inlaying, and grooves are chiseled at the bottom of the rotating rods; the rotating compass is connected to a motor, and the material of the rotating compass is an acrylic plate;

[0053] (4) Turn on the CNC heating magnetic stirrer, set the temperature of the CNC heating magnetic stirrer to 50°C, preheat for 5 minutes to allow the temperature to reach equilibrium, take 30 ml of the prepared 1.5 mol / L FeCl3 aqueous solution in a culture dish, and then place the culture dish on the CNC heating magnetic stirrer; place the rotating compass directly above the culture dish, adjust the height of the turntable so that the cotton fiber is completely immersed in the solution of the culture dish, and the rotating rod does not touch the bottom of the culture dish, connect the rotating compass to the motor, turn on the power, set the rotating compass speed to 8 rpm, and rotate the cotton fiber in the solution for 45 minutes. Take it out and dry it naturally to obtain the polyethylene dioxythiophene-based fiber thermoelectric material.

[0054] Example 2

[0055] A method for preparing a polyethylene dioxythiophene-based fiber thermoelectric material comprises the following steps:

[0056] (1) A cotton fiber with a length of 10 cm and a cross-sectional diameter of 300 μm was cut and placed in a beaker. It was ultrasonicated in secondary water and ethanol for 10 min each, and then placed in an oven at 50 °C for 2 h to dry;

[0057] (2) Immerse the cotton fiber in a 5 wt% Nafion solution for 10 seconds, then take it out and scrape it with tweezers three times; then immerse the cotton fiber in 99% pure EDOT for 30 seconds, then take it out and scrape it with tweezers three times;

[0058] (3) Wind the cotton thread fiber obtained in step (2) into Figure 2 In the groove on the rotating turntable rod shown;

[0059] (4) Turn on the CNC heating magnetic stirrer, set the temperature of the CNC heating magnetic stirrer to 50°C, preheat for 5 minutes to allow the temperature to reach equilibrium, take 30 ml of the prepared 1.5 mol / L FeCl3 aqueous solution in a culture dish, and then place the culture dish on the CNC heating magnetic stirrer; place the rotating compass directly above the culture dish, adjust the height of the turntable so that the cotton fiber is completely immersed in the solution of the culture dish, and the rotating rod does not touch the bottom of the culture dish, connect the rotating compass to the motor, turn on the power, set the rotating compass speed to 8 rpm, and rotate the cotton fiber in the solution for 45 minutes. Take it out and dry it naturally to obtain the polyethylene dioxythiophene-based fiber thermoelectric material.

[0060] Example 3

[0061] A method for preparing a polyethylene dioxythiophene-based fiber thermoelectric material comprises the following steps:

[0062] (1) A cotton fiber with a length of 30 cm and a cross-sectional diameter of 150 μm was cut and placed in a beaker. It was ultrasonicated in secondary water and ethanol for 10 min each, and then placed in an oven at 50 °C for 2 h to dry.

[0063] (2) Immerse the cotton fiber in a 5 wt% Nafion solution for 10 seconds, then take it out and scrape it with tweezers three times; then immerse the cotton fiber in 99% pure EDOT for 30 seconds, then take it out and scrape it with tweezers three times;

[0064] (3) Wind the cotton thread fiber obtained in step (2) into Figure 2 In the groove on the rotating turntable rod shown;

[0065] (4) Turn on the CNC heating magnetic stirrer, set the temperature of the CNC heating magnetic stirrer to 50°C, preheat for 5 minutes to allow the temperature to reach equilibrium, take 30 ml of the prepared 1.5 mol / L FeCl3 aqueous solution in a culture dish, and then place the culture dish on the CNC heating magnetic stirrer; place the rotating compass directly above the culture dish, adjust the height of the turntable so that the cotton fiber is completely immersed in the solution of the culture dish, and the rotating rod does not touch the bottom of the culture dish, connect the rotating compass to the motor, turn on the power, set the rotating compass speed to 8 rpm, and rotate the cotton fiber in the solution for 45 minutes. Take it out and dry it naturally to obtain the polyethylene dioxythiophene-based fiber thermoelectric material.

[0066] Example 4

[0067] A method for preparing a polyethylene dioxythiophene-based fiber thermoelectric material comprises the following steps:

[0068] (1) A cotton fiber with a length of 30 cm and a cross-sectional diameter of 300 μm was cut and placed in a beaker. It was ultrasonicated in secondary water and ethanol for 10 min each, and then placed in an oven at 50 °C for 2 h to dry;

[0069] (2) The cotton fiber was immersed in a 5 wt% Nafion solution for 10 seconds, then taken out and scraped with tweezers three times; then the cotton fiber was immersed in 99% pure EDOT for 300 seconds, then taken out and scraped with tweezers three times;

[0070] (3) Wind the cotton thread fiber obtained in step (2) into Figure 2 In the groove on the rotating turntable rod shown;

[0071] (4) Turn on the CNC heating magnetic stirrer, set the temperature of the CNC heating magnetic stirrer to 50°C, preheat for 5 minutes to allow the temperature to reach equilibrium, take 30 ml of the prepared 1.5 mol / L FeCl3 aqueous solution in a culture dish, and then place the culture dish on the CNC heating magnetic stirrer; place the rotating compass directly above the culture dish, adjust the height of the turntable so that the cotton fiber is completely immersed in the solution of the culture dish, and the rotating rod does not touch the bottom of the culture dish, connect the rotating compass to the motor, turn on the power, set the rotating compass speed to 8 rpm, and rotate the cotton fiber in the solution for 45 minutes. Take it out and dry it naturally to obtain the polyethylene dioxythiophene-based fiber thermoelectric material.

[0072] Example 5

[0073] A method for preparing a polyethylene dioxythiophene-based fiber thermoelectric material comprises the following steps:

[0074] (1) A cotton fiber with a length of 30 cm and a cross-sectional diameter of 300 μm was cut and placed in a beaker. It was ultrasonicated in secondary water and ethanol for 10 min each, and then placed in an oven at 50 °C for 2 h to dry;

[0075] (2) Immerse the cotton fiber in a 5 wt% Nafion solution for 10 seconds, then take it out and scrape it with tweezers three times; then immerse the cotton fiber in 99% pure EDOT for 30 seconds, then take it out and scrape it with tweezers three times;

[0076] (3) Wind the cotton thread fiber obtained in step (2) into Figure 2 In the groove on the rotating turntable rod shown;

[0077] (4) Turn on the CNC heating magnetic stirrer, set the temperature of the CNC heating magnetic stirrer to 50°C, preheat for 5 minutes to allow the temperature to reach equilibrium, take 30 ml of the prepared 0.1 mol / L FeCl3 aqueous solution in a culture dish, and then place the culture dish on the CNC heating magnetic stirrer; place the rotating compass directly above the culture dish, adjust the height of the turntable so that the cotton fiber is completely immersed in the solution of the culture dish, and the rotating rod does not touch the bottom of the culture dish, connect the rotating compass to the motor, turn on the power, set the rotating compass speed to 8 rpm, and rotate the cotton fiber in the solution for 45 minutes. Take it out and dry it naturally to obtain the polyethylene dioxythiophene-based fiber thermoelectric material.

[0078] Example 6

[0079] A method for preparing a polyethylene dioxythiophene-based fiber thermoelectric material comprises the following steps:

[0080] (1) A cotton fiber with a length of 30 cm and a cross-sectional diameter of 300 μm was cut and placed in a beaker. It was ultrasonicated in secondary water and ethanol for 10 min each, and then placed in an oven at 50 °C for 2 h to dry;

[0081] (2) Immerse the cotton fiber in a 5 wt% Nafion solution for 10 seconds, then take it out and scrape it with tweezers three times; then immerse the cotton fiber in 99% pure EDOT for 30 seconds, then take it out and scrape it with tweezers three times;

[0082] (3) Wind the cotton thread fiber obtained in step (2) into Figure 2 In the groove on the rotating turntable rod shown;

[0083] (4) Turn on the CNC heating magnetic stirrer, set the temperature of the CNC heating magnetic stirrer to 50°C, preheat for 5 minutes to allow the temperature to reach equilibrium, take 30 ml of the prepared 1.5 mol / L FeCl3 aqueous solution in a culture dish, and then place the culture dish on the CNC heating magnetic stirrer; place the rotating compass directly above the culture dish, adjust the height of the turntable so that the cotton fiber is completely immersed in the solution of the culture dish, and the rotating rod does not touch the bottom of the culture dish, connect the rotating compass to the motor, turn on the power, set the rotating compass speed to 32 rpm, and rotate the cotton fiber in the solution for 45 minutes. Take it out and dry it naturally to obtain the polyethylene dioxythiophene-based fiber thermoelectric material.

[0084] Example 7

[0085] A method for preparing a polyethylene dioxythiophene-based fiber thermoelectric material comprises the following steps:

[0086] (1) A cotton fiber with a length of 30 cm and a cross-sectional diameter of 300 μm was cut and placed in a beaker. It was ultrasonicated in secondary water and ethanol for 10 min each, and then placed in an oven at 50 °C for 2 h to dry;

[0087] (2) Immerse the cotton fiber in a 5 wt% Nafion solution for 10 seconds, then take it out and scrape it with tweezers three times; then immerse the cotton fiber in 99% pure EDOT for 30 seconds, then take it out and scrape it with tweezers three times;

[0088] (3) Wind the cotton thread fiber obtained in step (2) into Figure 2 In the groove on the rotating turntable rod shown;

[0089] (4) Turn on the CNC heating magnetic stirrer, set the temperature of the CNC heating magnetic stirrer to 40°C, preheat for 5 minutes to allow the temperature to reach equilibrium, take 30 ml of the prepared 1.5 mol / L FeCl3 aqueous solution in a culture dish, and then place the culture dish on the CNC heating magnetic stirrer; place the rotating compass directly above the culture dish, adjust the height of the turntable so that the cotton fiber is completely immersed in the solution of the culture dish, and the rotating rod does not touch the bottom of the culture dish, connect the rotating compass to the motor, turn on the power, set the rotating compass speed to 8 rpm, and rotate the cotton fiber in the solution for 120 minutes. Take it out and dry it naturally to obtain the polyethylene dioxythiophene-based fiber thermoelectric material.

[0090] Comparative Example 1

[0091] A method for preparing a polyethylene dioxythiophene-based fiber thermoelectric material comprises the following steps:

[0092] (1) A cotton fiber with a length of 30 cm and a cross-sectional diameter of 300 μm was cut and placed in a beaker. It was ultrasonicated in secondary water and ethanol for 10 min each, and then placed in an oven at 50 °C for 2 h to dry;

[0093] (2) Immerse the cotton fiber in 99% pure EDOT for 30 seconds, then take it out and scrape it with tweezers three times;

[0094] (3) Wind the cotton thread fiber obtained in step (2) into Figure 2 In the groove on the rotating turntable rod shown;

[0095] (4) Turn on the CNC heating magnetic stirrer, set the temperature of the CNC heating magnetic stirrer to 50°C, preheat for 5 minutes to allow the temperature to reach equilibrium, take 30 ml of the prepared 1.5 mol / L FeCl3 aqueous solution in a culture dish, and then place the culture dish on the CNC heating magnetic stirrer; place the rotating compass directly above the culture dish, adjust the height of the turntable so that the cotton fiber is completely immersed in the solution of the culture dish, and the rotating rod does not touch the bottom of the culture dish, connect the rotating compass to the motor, turn on the power, set the rotating compass speed to 8 rpm, and rotate the cotton fiber in the solution for 120 minutes. Take it out and dry it naturally to obtain the polyethylene dioxythiophene-based fiber thermoelectric material.

[0096] Comparative Example 2

[0097] A method for preparing a polyethylene dioxythiophene-based fiber thermoelectric material comprises the following steps:

[0098] (1) A cotton fiber with a length of 30 cm and a cross-sectional diameter of 300 μm was cut and placed in a beaker. It was ultrasonicated in secondary water and ethanol for 10 min each, and then placed in an oven at 50 °C for 2 h to dry;

[0099] (2) Immerse the cotton fiber in a 5 wt% Nafion solution for 10 seconds, then take it out and scrape it with tweezers three times; then immerse the cotton fiber in 99% pure EDOT for 30 seconds, then take it out and scrape it with tweezers three times;

[0100] (3) Wind the cotton thread fiber obtained in step (2) into Figure 2 In the groove on the rotating turntable rod shown;

[0101] (4) Turn on the CNC heating magnetic stirrer, set the temperature of the CNC heating magnetic stirrer to 50°C, preheat for 5 minutes to allow the temperature to reach equilibrium, take 30 ml of the prepared 1.5 mol / L FeCl3 aqueous solution in a culture dish, and then place the culture dish on the CNC heating magnetic stirrer; place the rotating compass directly above the culture dish, adjust the height of the turntable so that the cotton fiber is completely immersed in the solution of the culture dish, and the rotating rod does not touch the bottom of the culture dish, the rotating compass does not rotate, and the cotton fiber is allowed to react in the solution for 50 minutes, taken out, and naturally dried to obtain the polyethylene dioxythiophene-based fiber thermoelectric material.

[0102] Comparative Example 3

[0103] A method for preparing a polyethylene dioxythiophene-based fiber thermoelectric material comprises the following steps:

[0104] (1) A cotton fiber with a length of 30 cm and a cross-sectional diameter of 300 μm was cut and placed in a beaker. It was ultrasonicated in secondary water and ethanol for 10 min each, and then placed in an oven at 50 °C for 2 h to dry;

[0105] (2) immersing the cotton fiber in a 5 wt% polystyrene sulfonic acid (PSS) solution for 10 seconds, then taking it out and scraping it with tweezers three times; then immersing the cotton fiber in 99% pure EDOT for 30 seconds, then taking it out and scraping it with tweezers three times;

[0106] (3) Wind the cotton thread fiber obtained in step (2) into Figure 2 In the groove on the rotating turntable rod shown;

[0107] (4) Turn on the CNC heating magnetic stirrer, set the temperature of the CNC heating magnetic stirrer to 50°C, preheat for 5 minutes to allow the temperature to reach equilibrium, take 30 ml of the prepared 1.5 mol / L FeCl3 aqueous solution in a culture dish, and then place the culture dish on the CNC heating magnetic stirrer; place the rotating compass directly above the culture dish, adjust the height of the turntable so that the cotton fiber is completely immersed in the solution of the culture dish, and the rotating rod does not touch the bottom of the culture dish, connect the rotating compass to the motor, turn on the power, set the rotating compass speed to 8 rpm, and let the cotton fiber stand in the solution for 50 minutes, take it out, and dry it naturally to obtain the polyethylene dioxythiophene-based fiber thermoelectric material.

[0108] The electrical conductivities and Seebeck coefficients of the polyethylene dioxythiophene-based fiber thermoelectric materials of Examples 1-7 and the polyethylene dioxythiophene-based fiber thermoelectric materials of Comparative Examples 1-3 were measured respectively.

[0109] Table 1 Electrical conductivity and Seebeck coefficient of polyethylene dioxythiophene-based fiber thermoelectric materials of Examples 1-7 and Comparative Examples 1-3

[0110] serial number Conductivity (S cm-1) Seebeck coefficient (μV K-1) Example 1 68.4 14.9 Example 2 66.3 15.8 Example 3 42.9 16.4 Example 4 39.7 15.3 Example 5 7.2 22.4 Example 6 29.4 19.7 Example 7 18.8 19.2 Comparative Example 1 4.6 17.2 Comparative Example 2 22.6 13.8 Comparative Example 3 3.18 16.9

[0111] As can be seen from Table 1, Examples 1-7 use cotton fibers as carriers to prepare polyethylene dioxythiophene-based fiber thermoelectric materials with high conductivity. During the preparation of the material in Comparative Example 1, Nafion was not added, and the PEDOT obtained could not be stably attached to the fiber, resulting in a small conductivity and Seebeck coefficient of the material, and poor thermoelectric performance of the material. During the preparation of the material in Comparative Example 2, the compass did not rotate. Under static conditions, EDOT was oxidized by ferric chloride to form PEDOT, but PEDOT formed granules instead of fibers under static conditions, and the thermoelectric performance of granular PEDOT was lower than that of the fibrous PEDOT material obtained in the embodiment of the present invention. During the preparation of the material in Comparative Example 3, PSS was used instead of Nafion to prepare PEDOT thermoelectric fibers. Due to the water solubility of PSS, PSS gradually dissolved into water during the preparation process, and PEDOT fell off the fiber, so that PEDOT could not be stably attached to the fiber, resulting in a small conductivity of the material and poor thermoelectric performance of the material. Comparative Examples 1, 2 and 3 show that Nafion and compass rotation play a crucial role in the formation of fibrous PEDOT on cotton fibers.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing a polyethylene dioxythiophene-based fiber thermoelectric material, characterized in that: The following steps are involved: (1) ultrasonically cleaning and drying the hygroscopic fiber; (2) soaking the hygroscopic fiber in Nafion solution and EDOT successively, so that Nafion and EDOT are successively adsorbed onto the hygroscopic fiber; the purity of the EDOT is not less than 99%; (3) Soaking the fiber obtained in step (2) in an aqueous solution of ferric chloride, and rotating the obtained fiber in the aqueous solution of ferric chloride for 5 min to 120 min under heating conditions to obtain the polyethylene dioxythiophene-based fiber thermoelectric material.

2. The method for preparing the polyethylene dioxythiophene-based fiber thermoelectric material according to claim 1, characterized in that: In the step (1), the diameter of the hygroscopic fiber is 0.01 mm-5 mm, and the length is 5 cm-10 m.

3. The method for preparing the polyethylene dioxythiophene-based fiber thermoelectric material according to claim 1, characterized in that: In the step (2), the concentration of the Nafion solution is 4wt%-6wt%.

4. The method for preparing the polyethylene dioxythiophene-based fiber thermoelectric material according to claim 1, characterized in that: In the step (2), the hygroscopic fiber is immersed in the Nafion solution for no more than 1800 seconds, and the hygroscopic fiber is immersed in the EDOT solution for no more than 300 seconds.

5. The method for preparing the polyethylene dioxythiophene-based fiber thermoelectric material according to claim 1, characterized in that: In the step (3), the concentration of the ferric chloride aqueous solution is 0.1 mol / L-3 mol / L.

6. The method for preparing the polyethylene dioxythiophene-based fiber thermoelectric material according to claim 1, characterized in that: In the step (3), the heating temperature is 20°C-80°C.

7. The method for preparing the polyethylene dioxythiophene-based fiber thermoelectric material according to claim 1, characterized in that: In the step (3), the rotation adopts a rotating compass, which includes a disc and a rotating rod. The rotating rod is arranged below the disc, and the rotating rod is connected to the disc by inlaying. A groove is chiseled on the bottom end of the rotating rod. The rotating compass is connected to a motor, and the fiber is rotated by being wound around the rotating rod.

8. The method for preparing the polyethylene dioxythiophene-based fiber thermoelectric material according to claim 1, characterized in that: Satisfy at least one of the following: (a) In step (1), the ultrasonic cleaning is performed by ultrasonic cleaning with water and ethanol respectively, and the ultrasonic cleaning time is 5 min to 30 min; (b) In step (1), the drying temperature is 30°C-100°C and the drying time is 0.5h-12h; (c) In step (3), the rotation speed does not exceed 32 rpm.

9. A polyethylene dioxythiophene-based fiber thermoelectric material prepared by the method for preparing a polyethylene dioxythiophene-based fiber thermoelectric material according to any one of claims 1 to 8.

10. Use of the polyethylene dioxythiophene-based fiber thermoelectric material according to claim 9 in conductive materials and thermoelectric materials.

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