A wood-like double-layer PEDOT:PSS-CNTs / collagen thermo-electro-gel composite phase change material, its preparation method and application.

Abstract

This invention discloses a wood-like structured bilayer PEDOT:PSS-CNTs / collagen thermo-electro-gel composite phase change material, its preparation method, and its application. The method includes: 1. Adding sodium polystyrene sulfonate, 3,4-ethylenedioxythiophene, and carbon nanotubes to deionized water, then adding an oxidant, reacting, and freeze-drying to obtain PEDOT:PSS-CNTs particles; 2. Adding oxidized sodium alginate, cellulose nanofibers, collagen, and PEDOT:PSS-CNTs particles to deionized water, then adding a silane coupling agent, reacting to obtain a PEDOT:PSS-CNTs / collagen co-suspension, and injecting it into a mold. 3. Oxidized sodium alginate, cellulose nanofibers, collagen, and PEDOT:PSS-CNTs particles were added to deionized water, followed by PEG and then a silane coupling agent. The reaction yielded a PEDOT:PSS-CNTs / collagen / PEG co-suspension, which was then injected into a mold containing the PEDOT:PSS-CNTs / collagen ice gel. Unidirectional freezing and freeze-drying were performed to obtain a wood-like, bilayer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material with excellent thermal energy storage and thermoelectric properties.

Description

Technical Field

[0001] This invention relates to flexible thermoelectric materials, specifically a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material, its preparation method, and its application. Background Technology

[0002] As smart wearable devices continue to develop towards low power consumption and portability, miniature flexible wearable generators that power them are attracting increasing attention. Among various power generation methods, using natural energy for power generation has significant advantages in terms of cleanliness and environmental friendliness. As a ubiquitous natural energy source, thermal energy makes wearable power generation devices based on thermal energy show broad development prospects.

[0003] Traditional inorganic thermoelectric materials (such as tellurides and silicon-germanium alloys) have been extensively studied due to their excellent thermoelectric properties. However, their rigidity, brittleness, and high density make them unsuitable for conformal contact with heat sources with complex or irregular geometries (such as the surface of automobile engines). In view of this, organic and carbon-based thermoelectric materials have become alternative materials to inorganic thermoelectric materials due to their flexibility, lightweight, and ease of processing.

[0004] Existing flexible thermoelectric devices are typically assembled by laying out organic thermoelectric thin films. Two-dimensional thermoelectric generators with parallel structures can only collect heat energy in a planar direction, making it difficult to match the vertical temperature gradient between the heat source and the environment. This results in generally low heat conversion efficiency and limited overall performance. In contrast, thermoelectric devices with vertical structures, with their thicker three-dimensional thermoelectric legs, can significantly increase the temperature difference between the hot and cold sides, thereby effectively utilizing the temperature gradient between the heat source and the environment to achieve higher output voltage and power. Wood in nature has an ordered, layered, porous structure, exhibiting significant anisotropy in the directional transport of water and nutrients. This unique ordered structure not only endows wood with certain load-bearing functions, but its internal hollow tubular structure can also serve as a load substrate for functional materials, providing an ideal platform for developing three-dimensional functional composite materials with excellent thermoelectric properties. Therefore, preparing thermoelectric gels with wood-like structures can both promote the orderly arrangement of conductive materials and increase the carrier migration rate, thereby enhancing the thermoelectric properties of aerogels, and endow the materials with good mechanical properties.

[0005] Meanwhile, phase change materials (PCMs) can absorb or release a large amount of heat energy during the phase change process, thereby realizing the functions of heat storage and temperature regulation. They have wide applications in fields such as smart fabrics, energy-saving buildings, commercial refrigeration and waste heat recovery. With its high energy storage density and near-isothermal phase change process, PCMs can store a large amount of latent heat and provide a stable heat source output, which helps thermoelectric generators obtain continuous and stable voltage.

[0006] In summary, it is expected that combining wood-like thermoelectric gels with phase change materials can endow thermoelectric generators with stable output performance and effectively extend their power generation time by utilizing the heat storage capacity of phase change materials. This can address the portable self-powered needs of smart wearable devices, which has significant value and importance for sustainable energy utilization and the stable and healthy development of the future flexible wearable field. Summary of the Invention

[0007] The purpose of this invention is to provide a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material, its preparation method, and its application. The prepared composite material has good thermal energy storage and thermoelectric properties.

[0008] This invention is achieved through the following technical solution: A method for preparing a wood-like double-layer PEDOT:PSS-CNTs / collagen thermo-electro-gel composite phase change material includes the following steps: Step 1: Preparation of PEDOT:PSS-CNTs particles Step 1.1: First, take sodium polystyrene sulfonate, 3,4-ethylenedioxythiophene, and carbon nanotubes in a mass ratio of (150~200):(50~100):(1~10). Then, add sodium polystyrene sulfonate to deionized water and stir until dissolved to obtain a sodium polystyrene sulfonate solution. Next, adjust the pH of the sodium polystyrene sulfonate solution to 1~3 with hydrochloric acid solution. Then, add 3,4-ethylenedioxythiophene and carbon nanotubes to the sodium polystyrene sulfonate solution and stir evenly to obtain mixed solution A. Step 1.2: According to the mass ratio of oxidant to 3,4-ethylenedioxythiophene (1~3):(0.5~1.5), add the oxidant to mixed solution A, stir for 12~24 h, and then add deionized water to obtain a dark blue PEDOT:PSS-CNTs dispersion, wherein the mass fraction of deionized water in the dark blue PEDOT:PSS-CNTs dispersion is 70%~90%. Step 1.3: Vacuum freeze-dry the dark blue PEDOT:PSS-CNTs dispersion to obtain PEDOT:PSS-CNTs particles; Step 2: Preparation of PEDOT:PSS-CNTs / Collagen Ice Gel Step 2.1: Take sodium alginate oxide, cellulose nanofibers, collagen, and PEDOT:PSS-CNTs particles according to the mass ratio (1~5):(1~5):50:(1~10), and then add sodium alginate oxide, cellulose nanofibers, collagen, and PEDOT:PSS-CNTs particles to deionized water to prepare sodium alginate oxide solution, cellulose nanofiber solution, collagen solution, and PEDOT:PSS-CNTs dispersion. At room temperature, add sodium alginate oxide solution and cellulose nanofiber solution dropwise to collagen solution and stir for 0.5~1.5 h. Then add PEDOT:PSS-CNTs dispersion and continue stirring for 0.5~1.5 h to obtain reaction solution B, wherein the mass fraction of deionized water in reaction solution B is 70%~80%. Step 2.2: According to the mass ratio of PEDOT:PSS-CNTs particles to silane coupling agent (10~20):(1~3), add silane coupling agent to reaction solution B, and stir at 10~50℃ for 6~18 h to obtain PEDOT:PSS-CNTs / collagen co-suspension. Step 2.3: Inject the PEDOT:PSS-CNTs / collagen co-suspension into the mold and freeze it in one direction to obtain PEDOT:PSS-CNTs / collagen ice gel. Step 3: Preparation of a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material Step 3.1: Take sodium alginate oxide, cellulose nanofibers, collagen, and PEDOT:PSS-CNTs particles according to the mass ratio (1~5):(1~5):(1~50):(1~10), and then add sodium alginate oxide, cellulose nanofibers, collagen, and PEDOT:PSS-CNTs particles to deionized water to prepare sodium alginate oxide solution, cellulose nanofiber solution, collagen solution, and PEDOT:PSS-CNTs dispersion. At room temperature, add sodium alginate oxide solution and cellulose nanofiber solution dropwise to collagen solution and stir for 0.5~1.5 h. Then add PEDOT:PSS-CNTs dispersion and continue stirring for 0.5~1.5 h to obtain reaction solution C, wherein the mass fraction of deionized water in reaction solution C is 70%~80%. Step 3.2: Add PEG to reaction solution C according to the mass ratio of PEG to collagen of (0.5~1.5):(10~20), mix and react for 0.5~1.5 h to obtain reaction solution D; Step 3.3: According to the mass ratio of PEDOT:PSS-CNTs particles to silane coupling agent (10~20):(1~3), add silane coupling agent to reaction solution D, and stir at 10~50℃ for 6~18 h to obtain PEDOT:PSS-CNTs / collagen / PEG co-suspension. Step 3.4: Inject the PEDOT:PSS-CNTs / collagen / PEG co-suspension into a mold containing PEDOT:PSS-CNTs / collagen ice gel, and then freeze-dry it in a unidirectional manner and under vacuum to obtain a wood-like bilayer PEDOT:PSS-CNTs / collagen thermo-electric gel composite phase change material.

[0009] Further, the carbon nanotubes in step 1.1 are single-walled carbon nanotubes or multi-walled carbon nanotubes, wherein: the single-walled carbon nanotubes have a diameter of 1~2 nm and a length of 1~3 μm or a diameter of 1~2 nm and a length of 5~30 μm; the multi-walled carbon nanotubes have a diameter of 8~15 nm and a length of 40~60 μm.

[0010] Further, the oxidant in step 1.2 is a mixture of persulfate and iron salt, wherein: the persulfate is ammonium persulfate and sodium persulfate; and the iron salt is anhydrous ferric sulfate and ferric p-toluenesulfonate.

[0011] Furthermore, the cellulose nanofibers in steps 2.1 and 3.1 are sodium carboxymethyl cellulose or TEMPO oxidized cellulose nanofibers.

[0012] Further, the silane coupling agent in steps 2.2 and 3.3 is γ-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, or 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0013] Furthermore, the unidirectional freezing in steps 2.3 and 3.4 is carried out at -30 to -80°C for 0.5 to 1 hour.

[0014] Furthermore, the molecular weight of the PEG in step 3.2 is 2000~10000.

[0015] Furthermore, the vacuum freeze-drying in step 3.4 is carried out using a vacuum freeze dryer at a pressure of 1~10 Pa and a temperature of -70~-50℃ for 24~72 h.

[0016] A wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material.

[0017] Application of a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material as a thermoelectric generator.

[0018] The present invention has the following beneficial technical effects: 1) This invention uses PEDOT:PSS-CNTs, PEG, and environmentally friendly and widely available collagen as raw materials, and sodium alginate oxide and silane coupling agents as crosslinking agents. Based on unidirectional cryogenic casting technology, a directional temperature gradient is formed in the solution. The arrangement and compression of collagen by ice crystals create a directional, ordered porous structure. The resulting wood-like bilayer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material not only possesses the advantages of being lightweight, flexible, having a large specific surface area and high porosity, but also exhibits good compression resilience, mechanical compressive strength, and thermoelectric conversion performance. This is attributed to: Firstly, The bilayer wood-like microstructure of the aerogel composite phase change material provides a rapid channel for carrier conduction, thereby achieving high thermoelectric conversion performance and providing a structural basis for high elasticity. Secondly, the one-dimensional CNTs bridge PEDOT molecules, improving carrier mobility and thus improving the material's electrical conductivity, giving PEDOT:PSS-CNTs excellent thermoelectric conversion performance. Thirdly, the phase change material PEG can store sufficient heat and achieve stable heat source output, thereby generating continuous and stable electrical energy. Therefore, the aerogel composite phase change material prepared in this invention has great potential in the fields of thermal regulation, energy harvesting and storage, and sensing.

[0019] 2) The preparation method of this invention is simple and the preparation process is controllable. By utilizing the interaction between PEDOT:PSS-CNTs, collagen and PEG, the phase change material PEG is added in situ, which can effectively prevent the phase change material from melting and leaking, and improve the shape stability of the phase change composite material. It can also retain the porous structure of the aerogel, which improves the flexibility of the phase change composite material. At the same time, by selecting PEG with an appropriate molecular weight and controlling the amount of PEG, the amount of PEDOT:PSS-CNTs and the ratio of PEDOT:PSS and CNTs, the heat storage and thermoelectric properties of the aerogel composite phase change material can be effectively regulated, so as to achieve high thermoelectric performance and continuous voltage output.

[0020] 3) The aerogel composite phase change material prepared by this invention is a p-type thermoelectric gel phase change composite material with a double-layer structure, wherein: the upper layer structure is a wood-like structure of PEDOT:PSS-CNTs modified collagen aerogel composite PEG with high-efficiency thermal energy storage layer, which has excellent thermal energy storage and good thermoelectric conversion performance; the lower layer structure is a wood-like structure of PEDOT:PSS-CNTs modified collagen aerogel with high-efficiency thermoelectric conversion performance, which has excellent thermoelectric conversion performance; when a heat source is present, a temperature gradient is generated inside the double-layer wood-like structure PEDOT:PSS-CNTs / collagen aerogel composite phase change material, and thermoelectric conversion is achieved by utilizing the Seebeck effect. At the same time, the upper layer structure can also use PEG to store part of the thermal energy. When there is no heat source, a temperature gradient is constructed for the double-layer wood-like structure PEDOT:PSS-CNTs / collagen aerogel composite phase change material, so that it can complete the thermoelectric conversion and extend the thermoelectric power generation time; 4) This invention utilizes the excellent thermoelectric properties of p-type materials to endow aerogel composite phase change materials with thermoelectric power generation performance. It also utilizes the vertical temperature difference channel of the wood-like structure aerogel phase change composite material to improve the thermoelectric power generation of the material. Furthermore, it takes advantage of the high energy storage density and near-isothermal phase change process of phase change materials to achieve stable heat source output. This enables the thermoelectric generator based on the wood-like structure aerogel phase change composite material to obtain a stable and continuous output voltage, meeting the portable self-powered power supply requirements of smart wearable devices. This invention has significant value and significance for the sustainable use of energy and the stable and healthy development of the future flexible wearable field. Attached Figure Description

[0021] Figure 1 Here are actual photographs and SEM images of the aerogel composite phase change material prepared in Example 2 of this invention; Figure 2 This is a schematic diagram of the mechanical compression and rebound of the aerogel composite phase change material prepared in Example 2 of the present invention; Figure 3 The compression cycle curves of the aerogel composite phase change material prepared in Example 2 of the present invention under different strains and after cyclic compression at 40% strain for different numbers of times are shown. Figure 4 The thermal insulation and temperature regulation performance of the aerogel composite phase change material prepared in Example 2 of this invention is shown in the figure. Figure 5 The aerogel composite phase change material prepared in Example 2 of this invention was placed on a heating stage at 100°C, and its output voltage and the temperature difference between the upper and lower surfaces were measured. Figure 6 This is a schematic diagram showing the shape stability of the aerogel composite phase change material prepared in Example 2 of the present invention under heating conditions; Figure 7 The thermoelectric wristband is assembled in series with the aerogel composite phase change material prepared in Example 2 of this invention. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0023] Example 1 Step 1: Preparation of PEDOT:PSS-CNTs particles Step 1.1: First, take 20 g of sodium polystyrene sulfonate (PSSNa), 5 g of 3,4-ethylenedioxythiophene (EDOT), and 0.1 g of single-walled carbon nanotubes with a diameter of 1-2 nm and a length of 1-3 μm, respectively, according to a mass ratio of 200:50:1. Then, add the sodium polystyrene sulfonate (PSSNa) to 200 g of deionized water and mechanically stir at 300 r / min until dissolved to obtain a sodium polystyrene sulfonate solution. Then, adjust the pH value of the sodium polystyrene sulfonate solution to 1-3 with a concentration of 0.1 mol / L hydrochloric acid solution. Next, add 3,4-ethylenedioxythiophene and single-walled carbon nanotubes to the sodium polystyrene sulfonate solution and stir at 600 r / min for 60 min to obtain mixed solution A. Step 1.2: According to the mass ratio of oxidant to 3,4-ethylenedioxythiophene (EDOT) 2:1, take 5 g of ammonium persulfate and 5 g of anhydrous ferric sulfate and mix them as oxidant. Add the oxidant to the mixed solution A in three portions within 30 min. Stir at 600 r / min for 24 h. Then add 115.9 g of deionized water to terminate the reaction and obtain a dark blue PEDOT:PSS-CNTs dispersion. Step 1.3: Vacuum freeze-dry the dark blue PEDOT:PSS-CNTs dispersion to obtain PEDOT:PSS-CNTs particles; Step 2: Preparation of PEDOT:PSS-CNTs / Collagen Ice Gel Step 2.1: Take 1 g of sodium alginate oxide, 1 g of sodium carboxymethyl cellulose, 50 g of collagen, and 1 g of PEDOT:PSS-CNTs particles according to a mass ratio of 1:1:50:1. Add sodium alginate oxide to 15 mL of deionized water to prepare sodium alginate oxide solution. Add sodium carboxymethyl cellulose to 15 mL of deionized water to prepare sodium carboxymethyl cellulose solution. Add collagen to 150 mL of deionized water to prepare collagen solution. Add PEDOT:PSS-CNTs particles to 32.4 mL of deionized water to prepare PEDOT:PSS-CNTs dispersion. At room temperature, add sodium carboxymethyl cellulose solution and sodium alginate oxide solution dropwise to collagen solution and stir for 0.5 h. Then add PEDOT:PSS-CNTs dispersion and continue stirring for 0.5 h to obtain reaction solution B. Step 2.2: According to the mass ratio of PEDOT:PSS-CNTs particles to silane coupling agent of 10:1, γ-glycidyl etheroxypropyltrimethoxysilane was added to reaction solution B, and stirred at 10℃ for 18 h to obtain PEDOT:PSS-CNTs / collagen co-suspension. Step 2.3: Inject the PEDOT:PSS-CNTs / collagen co-suspension into the mold, with the liquid level of the co-suspension being 2 / 3 of the inner height of the mold. Freeze unidirectionally at -30~-80℃ for 1 h to obtain PEDOT:PSS-CNTs / collagen ice gel. Step 3: Preparation of a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material Step 3.1: Take 1 g of sodium alginate oxide, 1 g of sodium carboxymethyl cellulose, 50 g of collagen, and 1 g of PEDOT:PSS-CNTs particles according to a mass ratio of 1:1:50:1. Add sodium alginate oxide to 15 mL of deionized water to prepare sodium alginate oxide solution. Add sodium carboxymethyl cellulose to 15 mL of deionized water to prepare sodium carboxymethyl cellulose solution. Add collagen to 150 mL of deionized water to prepare collagen solution. Add PEDOT:PSS-CNTs particles to 32.4 mL of deionized water to prepare PEDOT:PSS-CNTs dispersion. At room temperature, add sodium carboxymethyl cellulose solution and sodium alginate oxide solution dropwise to collagen solution and stir for 0.5 h. Then add PEDOT:PSS-CNTs dispersion and continue stirring for 0.5 h to obtain reaction solution C. Step 3.2: Add 5 g of PEG 6000 to reaction solution C according to the mass ratio of PEG to collagen of 1:10, mix and react for 0.5 h to obtain reaction solution D; Step 3.3: According to the mass ratio of PEDOT:PSS-CNTs particles to silane coupling agent of 10:1, 0.1 g of γ-glycidyl etheroxypropyltrimethoxysilane was added to reaction solution D, and stirred at 10℃ for 18 h to obtain PEDOT:PSS-CNTs / collagen / PEG co-suspension. Step 3.4: Inject the PEDOT:PSS-CNTs / collagen / PEG co-suspension into a mold containing PEDOT:PSS-CNTs / collagen ice gel, freeze it at -80℃ for 1 h, and then freeze-dry it for 72 h using a vacuum freeze dryer at a pressure of 10 Pa and a temperature of -50℃ to obtain a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material.

[0024] Example 2 Step 1: Preparation of PEDOT:PSS-CNTs particles Step 1.1: First, take 20 g of sodium polystyrene sulfonate (PSSNa), 5 g of 3,4-ethylenedioxythiophene (EDOT), and 0.1 g of single-walled carbon nanotubes with a diameter of 1~2 nm and a length of 5~30 μm, respectively, according to a mass ratio of 200:50:1. Then, add the sodium polystyrene sulfonate (PSSNa) to 200 g of deionized water and mechanically stir at 300 r / min until dissolved to obtain a sodium polystyrene sulfonate solution. Then, adjust the pH value of the sodium polystyrene sulfonate solution to 1 with a concentration of 0.1 mol / L hydrochloric acid solution. Next, add 3,4-ethylenedioxythiophene (EDOT) and single-walled carbon nanotubes to the sodium polystyrene sulfonate solution and stir at 600 r / min for 60 min to obtain mixed solution A. Step 1.2: According to the mass ratio of oxidant to 3,4-ethylenedioxythiophene (EDOT) 1:1, take 2.5 g of sodium persulfate and 2.5 g of ferric p-toluenesulfonate and mix them as oxidant. Add the oxidant to the mixed solution A in three portions within 30 min. Stir at 600 r / min for 24 h. Then add 70.9 g of deionized water to terminate the reaction and obtain a dark blue PEDOT:PSS-CNTs dispersion. Step 1.3: Vacuum freeze-dry the dark blue PEDOT:PSS-CNTs dispersion to obtain PEDOT:PSS-CNTs particles; Step 2: Preparation of PEDOT:PSS-CNTs / Collagen Ice Gel Step 2.1: Take 5 g of sodium alginate oxide, 5 g of sodium carboxymethyl cellulose, 50 g of collagen, and 1 g of PEDOT:PSS-CNTs particles according to a mass ratio of 5:5:50:1. Add sodium alginate oxide to 15 mL of deionized water to prepare sodium alginate oxide solution; add sodium carboxymethyl cellulose to 15 mL of deionized water to prepare sodium carboxymethyl cellulose solution; add collagen to 125 mL of deionized water to prepare collagen solution; add PEDOT:PSS-CNTs particles to 28.15 mL of deionized water to prepare PEDOT:PSS-CNTs dispersion. At room temperature, add sodium carboxymethyl cellulose solution and sodium alginate oxide solution dropwise to collagen solution and stir for 1.5 h. Then add PEDOT:PSS-CNTs dispersion and continue stirring for 1.5 h to obtain reaction solution B. Step 2.2: According to the mass ratio of PEDOT:PSS-CNTs particles to silane coupling agent of 20:1, take 0.05 g of γ-glycidoxypropyltrimethoxysilane and add it to reaction solution B. Stir at 30℃ for 12 h to obtain PEDOT:PSS-CNTs / collagen co-suspension. Step 2.3: Inject the PEDOT:PSS-CNTs / collagen co-suspension into the mold, and the liquid level of the co-suspension is 1 / 2 of the inner height of the mold. Freeze unidirectionally at -80℃ for 0.5 h to obtain PEDOT:PSS-CNTs / collagen ice gel. Step 3: Preparation of a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material Step 3.1: Take 5 g of sodium alginate oxide, 5 g of sodium carboxymethyl cellulose, 50 g of collagen, and 1 g of PEDOT:PSS-CNTs particles according to a mass ratio of 5:5:50:1. Add sodium alginate oxide to 15 mL of deionized water to prepare sodium alginate oxide solution; add sodium carboxymethyl cellulose to 15 mL of deionized water to prepare sodium carboxymethyl cellulose solution; add collagen to 125 mL of deionized water to prepare collagen solution; add PEDOT:PSS-CNTs particles to 28.15 mL of deionized water to prepare PEDOT:PSS-CNTs dispersion. At room temperature, add sodium carboxymethyl cellulose solution and sodium alginate oxide solution dropwise to collagen solution and stir for 1.5 h. Then add PEDOT:PSS-CNTs dispersion and continue stirring for 1.5 h to obtain reaction solution C. Step 3.2: According to the mass ratio of PEG to collagen of 0.5:10, take 2.5 g of PEG 10000 and add it to reaction solution C. Mix and react for 1.5 h to obtain reaction solution D. Step 3.3: According to the mass ratio of PEDOT:PSS-CNTs to silane coupling agent of 20:1, take 0.05 g of γ-glycidyl etheroxypropyltrimethoxysilane and add it to reaction solution D. Stir at 30℃ for 12 h to obtain PEDOT:PSS-CNTs / collagen / PEG co-suspension. Step 3.4: Inject the PEDOT:PSS-CNTs / collagen / PEG co-suspension into a mold containing PEDOT:PSS-CNTs / collagen ice gel, freeze it at -80℃ for 0.5 h, and then freeze-dry it for 48 h using a vacuum freeze dryer at a pressure of 1 Pa and a temperature of -70℃ to obtain a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material.

[0025] Example 3 Step 1: Preparation of PEDOT:PSS-CNTs particles Step 1.1: First, take 20 g of sodium polystyrene sulfonate (PSSNa), 5 g of 3,4-ethylenedioxythiophene (EDOT), and 1 g of single-walled carbon nanotubes with a diameter of 1~2 nm and a length of 1~3 μm, respectively, according to a mass ratio of 200:50:10. Then, add the sodium polystyrene sulfonate (PSSNa) to 200 g of deionized water and stir mechanically at 300 r / min until dissolved to obtain a sodium polystyrene sulfonate solution. Then, adjust the pH value of the sodium polystyrene sulfonate solution to 1 with a concentration of 0.1 mol / L hydrochloric acid solution. Next, add 3,4-ethylenedioxythiophene (EDOT) and single-walled carbon nanotubes to the sodium polystyrene sulfonate solution and stir at 600 r / min for 60 min to obtain mixed solution A. Step 1.2: According to the mass ratio of oxidant to 3,4-ethylenedioxythiophene (EDOT) 1:1, take 2.5 g of sodium ammonium persulfate and 2.5 g of ferric p-toluenesulfonate and mix them as oxidant. Add the oxidant to the mixed solution A in three portions within 30 min. Stir at 600 r / min for 24 h. Then add 79 g of deionized water to terminate the reaction and obtain a dark blue PEDOT:PSS-CNTs dispersion. Step 1.3: Vacuum freeze-dry the dark blue PEDOT:PSS-CNTs dispersion to obtain PEDOT:PSS-CNTs particles; Step 2: Preparation of PEDOT:PSS-CNTs / Collagen Ice Gel Step 2.1: Take 1 g of sodium alginate oxide, 1 g of sodium carboxymethyl cellulose, 50 g of collagen, and 10 g of PEDOT:PSS-CNTs particles according to a mass ratio of 1:1:50:10. Add sodium alginate oxide to 5 mL of deionized water to prepare sodium alginate oxide solution. Add sodium carboxymethyl cellulose to 5 mL of deionized water to prepare sodium carboxymethyl cellulose solution. Add collagen to 100 mL of deionized water to prepare collagen solution. Add PEDOT:PSS-CNTs particles to 35.83 mL of deionized water to prepare PEDOT:PSS-CNTs aqueous dispersion. At room temperature, add sodium carboxymethyl cellulose solution and sodium alginate oxide solution dropwise to collagen solution and stir for 1 h. Then add PEDOT:PSS-CNTs dispersion and continue stirring for 1 h to obtain reaction solution B. Step 2.2: According to the mass ratio of PEDOT:PSS-CNTs particles to silane coupling agent of 20:1, 0.5 g of γ-glycidyl etheroxypropyltrimethoxysilane was added to reaction solution B, and stirred at 30℃ for 18 h to obtain PEDOT:PSS-CNTs / collagen co-suspension. Step 2.3: Inject the PEDOT:PSS-CNTs / collagen co-suspension into the mold, with the liquid level of the co-suspension being 1 / 3 of the height inside the mold. Freeze unidirectionally at -80℃ for 0.5 h to obtain PEDOT:PSS-CNTs / collagen ice gel. Step 3: Preparation of a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material Step 3.1: Take 1 g of sodium alginate oxide, 1 g of sodium carboxymethyl cellulose, 50 g of collagen, and 10 g of PEDOT:PSS-CNTs particles according to a mass ratio of 1:1:50:10. Add sodium alginate oxide to 5 mL of deionized water to prepare sodium alginate oxide solution. Add sodium carboxymethyl cellulose to 5 mL of deionized water to prepare sodium carboxymethyl cellulose solution. Add collagen to 100 mL of deionized water to prepare collagen solution. Add PEDOT:PSS-CNTs particles to 35.83 mL of deionized water to prepare PEDOT:PSS-CNTs aqueous dispersion. At room temperature, add sodium carboxymethyl cellulose solution and sodium alginate oxide solution dropwise to collagen solution and stir for 1 h. Then add PEDOT:PSS-CNTs dispersion and continue stirring for 1 h to obtain reaction solution C. Step 3.2: Add 2.5 g of PEG 600 to reaction solution C according to the mass ratio of PEG to collagen of 1:20, mix and react for 1 h to obtain reaction solution D; Step 3.3: According to the mass ratio of PEDOT:PSS-CNTs to silane coupling agent of 20:1, 0.5 g of γ-glycidyl etheroxypropyltrimethoxysilane was added to reaction solution D, and stirred at 30℃ for 18 h to obtain PEDOT:PSS-CNTs / collagen / PEG co-suspension. Step 3.4: Inject the PEDOT:PSS-CNTs / collagen / PEG co-suspension into a mold containing PEDOT:PSS-CNTs / collagen ice gel, freeze it at -80℃ for 0.5 h, and then freeze-dry it for 24 h using a vacuum freeze dryer at a pressure of 1 Pa and a temperature of -70℃ to obtain a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material.

[0026] Example 4 Step 1: Preparation of PEDOT:PSS-CNTs particles Step 1.1: First, take 20 g of sodium polystyrene sulfonate (PSSNa), 10 g of 3,4-ethylenedioxythiophene (EDOT), and 1 g of multi-walled carbon nanotubes with a diameter of 8-15 nm and a length of 40-60 μm, respectively, according to a mass ratio of 200:100:10. Then, add the sodium polystyrene sulfonate (PSSNa) to 65.7 g of deionized water and mechanically stir at 300 r / min until dissolved to obtain a sodium polystyrene sulfonate solution. Then, adjust the pH value of the sodium polystyrene sulfonate solution to 2 with a concentration of 0.1 mol / L hydrochloric acid solution. Next, add 3,4-ethylenedioxythiophene (EDOT) and multi-walled carbon nanotubes to the sodium polystyrene sulfonate solution and stir at 600 r / min for 60 min to obtain mixed solution A. Step 1.2: According to the mass ratio of oxidant to 3,4-ethylenedioxythiophene (EDOT) of 3:1.5, take 10 g of sodium ammonium persulfate and 10 g of anhydrous ferric sulfate and mix them as oxidant. Add the oxidant to the mixed solution A in three portions within 30 min. Stir at 600 r / min for 12 h. Then add 53.3 g of deionized water to terminate the reaction and obtain a dark blue PEDOT:PSS-CNTs dispersion. Step 1.3: Vacuum freeze-dry the dark blue PEDOT:PSS-CNTs dispersion to obtain PEDOT:PSS-CNTs particles; Step 2: Preparation of PEDOT:PSS-CNTs / Collagen Ice Gel Step 2.1: Take 1 g of sodium alginate oxide, 1 g of TEMPO oxidized cellulose nanofibers, 50 g of collagen, and 1 g of PEDOT:PSS-CNTs particles according to a mass ratio of 1:1:50:1. Add sodium alginate oxide to 15 mL of deionized water to prepare sodium alginate oxide solution. Add TEMPO oxidized cellulose nanofibers to 15 mL of deionized water to prepare TEMPO oxidized cellulose nanofiber solution. Add collagen to 150 mL of deionized water to prepare collagen solution. Add PEDOT:PSS-CNTs to 32.4 mL of deionized water to prepare PEDOT:PSS-CNTs dispersion. At room temperature, add the TEMPO oxidized cellulose nanofiber solution and sodium alginate oxide solution dropwise to the collagen solution and stir for 1.5 h. Then add the PEDOT:PSS-CNTs dispersion and continue stirring for 1.5 h to obtain reaction solution B. Step 2.2: According to the mass ratio of PEDOT:PSS-CNTs particles to silane coupling agent of 10:3, 0.3 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane was added to reaction solution B, and stirred at 50℃ for 6 h to obtain PEDOT:PSS-CNTs / collagen co-suspension. Step 2.3: Inject the PEDOT:PSS-CNTs / collagen co-suspension into the mold, with the liquid level of the co-suspension being half the height of the mold. Freeze unidirectionally at -30℃ for 1 h to obtain PEDOT:PSS-CNTs / collagen ice gel. Step 3: Preparation of a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material Step 3.1: Take 1 g of sodium alginate oxide, 1 g of TEMPO oxidized cellulose nanofibers, 50 g of collagen, and 1 g of PEDOT:PSS-CNTs particles according to a mass ratio of 1:1:50:1. Add sodium alginate oxide to 15 mL of deionized water to prepare sodium alginate oxide solution. Add TEMPO oxidized cellulose nanofibers to 15 mL of deionized water to prepare TEMPO oxidized cellulose nanofiber solution. Add collagen to 150 mL of deionized water to prepare collagen solution. Add PEDOT:PSS-CNTs to 32.4 mL of deionized water to prepare PEDOT:PSS-CNTs dispersion. At room temperature, add the TEMPO oxidized cellulose nanofiber solution and sodium alginate oxide solution dropwise to the collagen solution and stir for 1.5 h. Then add the PEDOT:PSS-CNTs dispersion and continue stirring for 1.5 h to obtain reaction solution C. Step 3.2: Add 3.75 g of PEG 2000 to reaction solution C according to the mass ratio of PEG to collagen of 1.5:20, mix and react for 1.5 h to obtain reaction solution D; Step 3.3: According to the mass ratio of PEDOT:PSS-CNTs to silane coupling agent of 10:3, 0.3 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane was added to reaction solution D, and stirred at 50℃ for 6 h to obtain PEDOT:PSS-CNTs / collagen / PEG co-suspension. Step 3.4: Inject the PEDOT:PSS-CNTs / collagen / PEG co-suspension into a mold containing PEDOT:PSS-CNTs / collagen ice gel, freeze it at -30℃ for 1 h, and then freeze-dry it for 48 h using a vacuum freeze dryer at a pressure of 10 Pa and a temperature of -70℃ to obtain a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material.

[0027] Example 5 Step 1: Preparation of PEDOT:PSS-CNTs particles Step 1.1: First, take 15 g of sodium polystyrene sulfonate (PSSNa), 5 g of 3,4-ethylenedioxythiophene (EDOT), and 0.1 g of multi-walled carbon nanotubes with a diameter of 8-15 nm and a length of 40-60 μm, respectively, according to a mass ratio of 150:50:1. Then, add the sodium polystyrene sulfonate (PSSNa) to 70 g of deionized water and stir mechanically at 300 r / min until dissolved to obtain a sodium polystyrene sulfonate solution. Then, adjust the pH value of the sodium polystyrene sulfonate solution to 3 with a concentration of 0.1 mol / L hydrochloric acid solution. Next, add 3,4-ethylenedioxythiophene (EDOT) and multi-walled carbon nanotubes to the sodium polystyrene sulfonate solution and stir at 600 r / min for 60 min to obtain mixed solution A. Step 1.2: According to the mass ratio of oxidant to 3,4-ethylenedioxythiophene (EDOT) 3:0.5, take 15 g of sodium ammonium persulfate and 15 g of ferric p-toluenesulfonate and mix them as oxidant. Add the oxidant to the mixed solution A in three portions within 30 min. Stir at 600 r / min for 12 h. Then add 130.4 g of deionized water to terminate the reaction and obtain a dark blue PEDOT:PSS-CNTs dispersion. Step 1.3: Vacuum freeze-dry the dark blue PEDOT:PSS-CNTs dispersion to obtain PEDOT:PSS-CNTs particles; Step 2: Preparation of PEDOT:PSS-CNTs / Collagen Ice Gel Step 2.1: According to the mass ratio of 5:1:50:1, take 5 g of sodium alginate oxide, 1 g of sodium carboxymethyl cellulose, 50 g of collagen, and 1 g of PEDOT:PSS-CNTs particles respectively. Add sodium alginate oxide to 15 mL of deionized water to prepare sodium alginate oxide solution, add sodium carboxymethyl cellulose to 3 mL of deionized water to prepare sodium carboxymethyl cellulose solution, add collagen to 125 mL of deionized water to prepare collagen solution, and add PEDOT:PSS-CNTs particles to 28.15 mL of deionized water to prepare PEDOT:PSS-CNTs dispersion. At room temperature, add sodium carboxymethyl cellulose solution and sodium alginate oxide solution dropwise to collagen solution and stir for 1 h. Then add PEDOT:PSS-CNTs dispersion and continue stirring for 1 h to obtain reaction solution B. Step 2.2: According to the mass ratio of PEDOT:PSS-CNTs particles to silane coupling agent of 20:1, take 0.05g of γ-glycidyl etheroxypropyltrimethoxysilane and add it to reaction solution B. Stir at 30℃ for 18 h to obtain PEDOT:PSS-CNTs / collagen co-suspension. Step 2.3: Inject the PEDOT:PSS-CNTs / collagen co-suspension into the mold, with the liquid level of the co-suspension being 2 / 3 of the height inside the mold. Freeze unidirectionally at -80℃ for 1 h to obtain PEDOT:PSS-CNTs / collagen ice gel. Step 3: Preparation of a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material Step 3.1: According to the mass ratio of 5:1:50:1, take 5 g of sodium alginate oxide, 1 g of sodium carboxymethyl cellulose, 50 g of collagen, and 1 g of PEDOT:PSS-CNTs particles respectively. Add sodium alginate oxide to 15 mL of deionized water to prepare sodium alginate oxide solution, add sodium carboxymethyl cellulose to 3 mL of deionized water to prepare sodium carboxymethyl cellulose solution, add collagen to 125 mL of deionized water to prepare collagen solution, and add PEDOT:PSS-CNTs particles to 28.15 mL of deionized water to prepare PEDOT:PSS-CNTs dispersion. At room temperature, add sodium carboxymethyl cellulose solution and sodium alginate oxide solution dropwise to collagen solution and stir for 1 h. Then add PEDOT:PSS-CNTs dispersion and continue stirring for 1 h to obtain reaction solution C. Step 3.2: Add 7.5 g of PEG10000 to reaction solution C according to the mass ratio of PEG to collagen of 1.5:10, mix and react for 1 h to obtain reaction solution D; Step 3.3: According to the mass ratio of PEDOT:PSS-CNTs to silane coupling agent of 20:1, 0.05 g of γ-glycidyl etheroxypropyltrimethoxysilane was added to reaction solution D, and stirred at 30℃ for 18 h to obtain PEDOT:PSS-CNTs / collagen / PEG co-suspension. Step 3.4: Inject the PEDOT:PSS-CNTs / collagen / PEG co-suspension into a mold containing PEDOT:PSS-CNTs / collagen ice gel, freeze it at -80℃ for 1 h, and then freeze-dry it for 72 h using a vacuum freeze dryer at a pressure of 10 Pa and a temperature of -70℃ to obtain a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material.

[0028] Example 6 Step 1: Preparation of PEDOT:PSS-CNTs particles Step 1.1: First, take 15 g of sodium polystyrene sulfonate (PSSNa), 10 g of 3,4-ethylenedioxythiophene (EDOT), and 0.1 g of multi-walled carbon nanotubes with a diameter of 8-15 nm and a length of 40-60 μm, respectively, according to a mass ratio of 150:100:1. Then, add the sodium polystyrene sulfonate (PSSNa) to 75 g of deionized water and stir mechanically at 300 r / min until dissolved to obtain a sodium polystyrene sulfonate solution. Then, adjust the pH value of the sodium polystyrene sulfonate solution to 3 with a concentration of 0.1 mol / L hydrochloric acid solution. Next, add 3,4-ethylenedioxythiophene (EDOT) and multi-walled carbon nanotubes to the sodium polystyrene sulfonate solution and stir at 600 r / min for 60 min to obtain mixed solution A. Step 1.2: According to the mass ratio of oxidant to 3,4-ethylenedioxythiophene (EDOT) 1:0.5, take 10 g of sodium ammonium persulfate and 10 g of anhydrous ferric sulfate and mix them as oxidant. Add the oxidant to the mixed solution A in three portions within 30 min. Stir at 600 r / min for 12 h. Then add 110.4 g of deionized water to terminate the reaction and obtain a dark blue PEDOT:PSS-CNTs dispersion. Step 1.3: Vacuum freeze-dry the dark blue PEDOT:PSS-CNTs dispersion to obtain PEDOT:PSS-CNTs particles; Step 2: Preparation of PEDOT:PSS-CNTs / Collagen Ice Gel Step 2.1: According to the mass ratio of 1:5:50:1, take 1 g of sodium alginate oxide, 5 g of TEMPO oxidized cellulose nanofibers, 50 g of collagen, and 1 g of PEDOT:PSS-CNTs particles respectively. Add sodium alginate oxide to 3 mL of deionized water to prepare sodium alginate oxide solution. Add TEMPO oxidized cellulose nanofibers to 15 mL of deionized water to prepare TEMPO oxidized cellulose nanofiber solution. Add collagen to 125 mL of deionized water to prepare collagen solution. Add PEDOT:PSS-CNTs particles to 28.15 mL of deionized water to prepare PEDOT:PSS-CNTs aqueous dispersion. At room temperature, add the TEMPO oxidized cellulose nanofiber solution and sodium alginate oxide solution dropwise to the collagen solution and stir for 1.5 h. Then add the PEDOT:PSS-CNTs dispersion and continue stirring for 1.5 h to obtain reaction solution B. Step 2.2: According to the mass ratio of PEDOT:PSS-CNTs particles to silane coupling agent of 20:3, 0.15 g of 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane was added to reaction solution B, and stirred at 50℃ for 12 h to obtain PEDOT:PSS-CNTs / collagen co-suspension. Step 2.3: Inject the PEDOT:PSS-CNTs / collagen co-suspension into the mold, with the liquid level of the co-suspension being 2 / 3 of the height inside the mold. Freeze unidirectionally at -50℃ for 0.5 h to obtain PEDOT:PSS-CNTs / collagen ice gel. Step 3: Preparation of a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material Step 3.1: According to the mass ratio of 1:5:50:1, take 1 g of sodium alginate oxide, 5 g of TEMPO oxidized cellulose nanofibers, 50 g of collagen, and 1 g of PEDOT:PSS-CNTs particles respectively. Add sodium alginate oxide to 3 mL of deionized water to prepare sodium alginate oxide solution. Add TEMPO oxidized cellulose nanofibers to 15 mL of deionized water to prepare TEMPO oxidized cellulose nanofiber solution. Add collagen to 125 mL of deionized water to prepare collagen solution. Add PEDOT:PSS-CNTs particles to 28.15 mL of deionized water to prepare PEDOT:PSS-CNTs aqueous dispersion. At room temperature, add the TEMPO oxidized cellulose nanofiber solution and sodium alginate oxide solution dropwise to the collagen solution and stir for 1.5 h. Then add the PEDOT:PSS-CNTs dispersion and continue stirring for 1.5 h to obtain reaction solution C. Step 3.2: According to the mass ratio of PEG to collagen of 0.5:20, take 1.25 g of PEG 2000 and add it to reaction solution C. Mix and react for 1.5 h to obtain reaction solution D. Step 3.3: According to the mass ratio of PEDOT:PSS-CNTs to silane coupling agent of 20:3, 0.15 g of 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane was added to reaction solution D, and stirred at 50℃ for 12 h to obtain PEDOT:PSS-CNTs / collagen / PEG co-suspension. Step 3.4: Inject the PEDOT:PSS-CNTs / collagen / PEG co-suspension into a mold containing PEDOT:PSS-CNTs / collagen ice gel, freeze it at -50℃ for 0.5 h, and then freeze-dry it for 48 h using a vacuum freeze dryer at a pressure of 5 Pa and a temperature of -50℃ to obtain a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material.

[0029] Example 7 Step 1: Preparation of PEDOT:PSS-CNTs particles Step 1.1: First, take 17.5 g of sodium polystyrene sulfonate (PSSNa), 7.5 g of 3,4-ethylenedioxythiophene (EDOT), and 0.5 g of multi-walled carbon nanotubes with a diameter of 8-15 nm and a length of 40-60 μm, respectively, according to a mass ratio of 175:75:5. Then, add the sodium polystyrene sulfonate (PSSNa) to 105 g of deionized water and mechanically stir at 300 r / min until dissolved to obtain a sodium polystyrene sulfonate solution. Then, adjust the pH value of the sodium polystyrene sulfonate solution to 2 with a 0.1 mol / L hydrochloric acid solution. Next, add 3,4-ethylenedioxythiophene (EDOT) and multi-walled carbon nanotubes to the sodium polystyrene sulfonate solution and stir at 600 r / min for 60 min to obtain mixed solution A. Step 1.2: According to the mass ratio of oxidant to 3,4-ethylenedioxythiophene (EDOT) of 1:1.5, take 2.5 g of sodium persulfate and 2.5 g of anhydrous ferric sulfate and mix them as oxidant. Add the oxidant to the mixed solution A in three portions within 30 min. Stir at 600 r / min for 12 h. Then add 169.5 g of deionized water to terminate the reaction and obtain a dark blue PEDOT:PSS-CNTs dispersion. Step 1.3: Vacuum freeze-dry the dark blue PEDOT:PSS-CNTs dispersion to obtain PEDOT:PSS-CNTs particles; Step 2: Preparation of PEDOT:PSS-CNTs / Collagen Ice Gel Step 2.1: Take 3 g of sodium alginate oxide, 3 g of TEMPO oxidized cellulose nanofibers, 50 g of collagen, and 5 g of PEDOT:PSS-CNTs particles according to a mass ratio of 3:3:50:5. Add sodium alginate oxide to 9 mL of deionized water to prepare sodium alginate oxide solution. Add TEMPO oxidized cellulose nanofibers to 9 mL of deionized water to prepare TEMPO oxidized cellulose nanofiber solution. Add collagen to 100 mL of deionized water to prepare collagen solution. Add PEDOT:PSS-CNTs particles to 24.5 mL of deionized water to prepare PEDOT:PSS-CNTs dispersion. At room temperature, add the TEMPO oxidized cellulose nanofiber solution and sodium alginate oxide solution dropwise to the collagen solution and stir for 0.5 h. Then add the PEDOT:PSS-CNTs dispersion and continue stirring for 0.5 h to obtain reaction solution B. Step 2.2: According to the mass ratio of PEDOT:PSS-CNTs particles to silane coupling agent of 15:2, 0.67 g of 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane was added to reaction solution B, and stirred at 40℃ for 15 h to obtain PEDOT:PSS-CNTs / collagen co-suspension. Step 2.3: Inject the PEDOT:PSS-CNTs / collagen co-suspension into the mold and freeze it unidirectionally at -60℃ for 0.75h to obtain PEDOT:PSS-CNTs / collagen ice gel. Step 3: Preparation of a wood-like double-layer PEDOT:PSS-CNT / collagen thermoelectric gel composite phase change material Step 3.1: Take 3 g of sodium alginate oxide, 3 g of TEMPO oxidized cellulose nanofibers, 50 g of collagen, and 5 g of PEDOT:PSS-CNTs particles according to a mass ratio of 3:3:50:5. Add sodium alginate oxide to 9 mL of deionized water to prepare sodium alginate oxide solution. Add TEMPO oxidized cellulose nanofibers to 9 mL of deionized water to prepare TEMPO oxidized cellulose nanofiber solution. Add collagen to 100 mL of deionized water to prepare collagen solution. Add PEDOT:PSS-CNTs particles to 24.5 mL of deionized water to prepare PEDOT:PSS-CNTs dispersion. At room temperature, add the TEMPO oxidized cellulose nanofiber solution and sodium alginate oxide solution dropwise to the collagen solution and stir for 0.5 h. Then add the PEDOT:PSS-CNTs dispersion and continue stirring for 0.5 h to obtain reaction solution C. Step 3.2: Add 3.34 g of PEG 8000 to reaction solution C according to the mass ratio of PEG to collagen of 1:15, mix and react for 0.5 h to obtain reaction solution D; Step 3.3: According to the mass ratio of PEDOT:PSS-CNTs to silane coupling agent of 15:2, take 0.67 g of 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane and add it to reaction solution D. Stir at 40℃ for 15 h to obtain PEDOT:PSS-CNTs / collagen / PEG co-suspension. Step 3.4: Inject the PEDOT:PSS-CNTs / collagen / PEG co-suspension into a mold containing PEDOT:PSS-CNTs / collagen ice gel, freeze it at -60℃ for 0.75 h, and then freeze-dry it for 36 h using a vacuum freeze dryer at a pressure of 6 Pa and a temperature of -60℃ to obtain a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material.

[0030] Figure 1 In Figure a, there is a photograph of the wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material prepared in Example 2. It can be seen that when the aerogel composite phase change material is placed on a petal, the petal will not be crushed, indicating that it has lightweight properties. Figure 1 b~c are SEM images of the cross section and longitudinal section of the upper structure (i.e., PEDOT:PSS-CNTs / collagen thermo-electro-gel composite phase change material) of the wood-like structure prepared in Example 2. It can be seen that the upper structure of the aerogel composite phase change material exhibits an interconnected porous structure in the radial direction (perpendicular to the ice growth direction) and an ordered parallel sheet structure in the axial direction (parallel to the ice growth direction). Figure 1 In Figure d, the SEM image shows the longitudinal section at the interface between the upper and lower layers of the wood-like bilayer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material prepared in Example 2. It can be seen that the upper and lower layers of the aerogel composite phase change material are very firmly bonded. Figure 1In Figures e to f, the cross-sectional and longitudinal sections of the lower layer (i.e., the PEDOT:PSS-CNTs / collagen thermo-electro-gel composite phase change material) of the wood-like double-layer PEDOT:PSS-CNTs / collagen aerogel layer prepared in Example 2 are SEM images. It can be seen that the lower layer of the aerogel composite phase change material exhibits an interconnected porous structure in the radial direction and an ordered parallel sheet structure in the axial direction. Moreover, the porous structure of the lower layer is sparser than that of the upper layer, and the tubular pores are larger.

[0031] Figure 2 This is a schematic diagram of the mechanical compression and rebound of the wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material prepared in Example 2 of the present invention. The original aerogel composite phase change material was compressed by 60% using an electronic universal testing machine. After the load was removed, the aerogel composite phase change material almost completely recovered, indicating that the aerogel composite phase change material has excellent compressibility.

[0032] Figure 3 Figures a to b show the compression cycle curves of the wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material prepared in Example 2 of this invention under different strains and at 40% strain, after different numbers of cyclic compressions. It can be seen that the material has good resilience at 20%, 40%, and 60% strains. At 40% strain, it can still maintain good compression resilience after 500 cyclic compressions, demonstrating excellent high elasticity and durability.

[0033] The wood-like bilayer PEDOT:PSS-CNTs / collagen thermo-electro-gel composite phase change materials prepared in Examples 1-3 of this invention were placed on a 100°C heating stage, with the upper structure (i.e., the PEDOT:PSS-CNTs / collagen / PEG layer) in contact with the heating stage. Heating was carried out for 1 hour, followed by removal to room temperature for natural cooling. The temperature changes of the aerogel composite phase change materials during heating and cooling were recorded using an infrared thermal imager, as shown below. Figure 4 The thermal insulation and temperature regulation performance diagram shown indicates that the aerogel composite phase change material exhibits significant temperature delay during both heating and cooling processes, demonstrating its excellent temperature regulation capability. Furthermore, the thermal insulation and temperature regulation performance improves with increasing PEG layer thickness.

[0034] The wood-like bilayer PEDOT:PSS-CNTs / collagen thermo-electro-gel composite phase change materials prepared in Examples 1-3 of this invention were placed on a 100°C heating stage, with the upper layer (i.e., the PEDOT:PSS-CNTs / collagen / PEG layer) in contact with the heating stage. Heating was performed for 125 min, followed by removal to room temperature for natural cooling. The temperature difference between the upper and lower surfaces of the aerogel composite phase change material during heating and cooling was measured using a thermocouple thermometer. Simultaneously, the voltage change during heating and cooling was measured using a digital multimeter. The results are as follows: Figure 5 As shown in Figures a and b, the output voltage and temperature difference curves of the upper and lower surfaces show that the output voltage of the aerogel composite phase change material increases with the increase of the temperature difference between the upper and lower surfaces. Due to the temperature delay during the cooling process, it can maintain the voltage output for a longer period of time during the cooling process. In addition, with the increase of the thickness of the PEG layer, its thermal insulation and temperature regulation properties are better, but its thermoelectric performance will decrease accordingly, which will affect its overall power output.

[0035] The PEG and the wood-like bilayer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material prepared in Example 2 of this invention were placed on a heating stage at 80°C, with the upper structure (i.e., the PEDOT:PSS-CNTs / collagen / PEG layer) in contact with the heating stage. Heating was performed for 3 hours, and the appearance changes were observed. The results are as follows: Figure 6 As shown, after heating for 20 min, PEG completely melted and liquefied. After heating for 180 min, the filter paper under the aerogel composite phase change material was still not wetted, indicating that the aerogel composite phase change material has excellent shape stability.

[0036] Nine wood-like bilayer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change materials prepared in Example 2 of this invention were assembled in series to form a thermoelectric wristband. Figure 7 It can be seen that the temperature difference generated when the thermoelectric wristband is worn on the human wrist can power the diode and the timer.

Claims

1. A method for preparing a wood-like double-layer PEDOT:PSS-CNTs / collagen thermo-electro-gel composite phase change material, characterized in that, Includes the following steps: Step 1: Preparation of PEDOT:PSS-CNTs particles Step 1.1: First, take sodium polystyrene sulfonate, 3,4-ethylenedioxythiophene, and carbon nanotubes in a mass ratio of (150~200):(50~100):(1~10). Then, add sodium polystyrene sulfonate to deionized water and stir until dissolved to obtain a sodium polystyrene sulfonate solution. Next, adjust the pH of the sodium polystyrene sulfonate solution to 1~3 with hydrochloric acid solution. Then, add 3,4-ethylenedioxythiophene and carbon nanotubes to the sodium polystyrene sulfonate solution and stir evenly to obtain mixed solution A. Step 1.2: According to the mass ratio of oxidant to 3,4-ethylenedioxythiophene (1~3):(0.5~1.5), add the oxidant to mixed solution A, stir for 12~24 h, and then add deionized water to obtain a dark blue PEDOT:PSS-CNTs dispersion, wherein the mass fraction of deionized water in the dark blue PEDOT:PSS-CNTs dispersion is 70%~90%. Step 1.3: Vacuum freeze-dry the dark blue PEDOT:PSS-CNTs dispersion to obtain PEDOT:PSS-CNTs particles; Step 2: Preparation of PEDOT:PSS-CNTs / Collagen Ice Gel Step 2.1: Take sodium alginate oxide, cellulose nanofibers, collagen, and PEDOT:PSS-CNTs particles according to the mass ratio (1~5):(1~5):50:(1~10), and then add sodium alginate oxide, cellulose nanofibers, collagen, and PEDOT:PSS-CNTs particles to deionized water to prepare sodium alginate oxide solution, cellulose nanofiber solution, collagen solution, and PEDOT:PSS-CNTs dispersion. At room temperature, add sodium alginate oxide solution and cellulose nanofiber solution dropwise to collagen solution and stir for 0.5~1.5 h. Then add PEDOT:PSS-CNTs dispersion and continue stirring for 0.5~1.5 h to obtain reaction solution B, wherein the mass fraction of deionized water in reaction solution B is 70%~80%. Step 2.2: According to the mass ratio of PEDOT:PSS-CNTs particles to silane coupling agent (10~20):(1~3), add silane coupling agent to reaction solution B, and stir at 10~50℃ for 6~18 h to obtain PEDOT:PSS-CNTs / collagen co-suspension. Step 2.3: Inject the PEDOT:PSS-CNTs / collagen co-suspension into the mold and freeze it in one direction to obtain PEDOT:PSS-CNTs / collagen ice gel. Step 3: Preparation of a wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material Step 3.1: Take sodium alginate oxide, cellulose nanofibers, collagen, and PEDOT:PSS-CNTs particles according to the mass ratio (1~5):(1~5):(1~50):(1~10), and then add sodium alginate oxide, cellulose nanofibers, collagen, and PEDOT:PSS-CNTs particles to deionized water to prepare sodium alginate oxide solution, cellulose nanofiber solution, collagen solution, and PEDOT:PSS-CNTs dispersion. At room temperature, add sodium alginate oxide solution and cellulose nanofiber solution dropwise to collagen solution and stir for 0.5~1.5 h. Then add PEDOT:PSS-CNTs dispersion and continue stirring for 0.5~1.5 h to obtain reaction solution C, wherein the mass fraction of deionized water in reaction solution C is 70%~80%. Step 3.2: Add PEG to reaction solution C according to the mass ratio of PEG to collagen of (0.5~1.5):(10~20), mix and react for 0.5~1.5 h to obtain reaction solution D; Step 3.3: According to the mass ratio of PEDOT:PSS-CNTs particles to silane coupling agent (10~20):(1~3), add silane coupling agent to reaction solution D, and stir at 10~50℃ for 6~18 h to obtain PEDOT:PSS-CNTs / collagen / PEG co-suspension. Step 3.4: Inject the PEDOT:PSS-CNTs / collagen / PEG co-suspension into a mold containing PEDOT:PSS-CNTs / collagen ice gel, and then freeze-dry it in a unidirectional manner and under vacuum to obtain a wood-like bilayer PEDOT:PSS-CNTs / collagen thermo-electric gel composite phase change material.

2. The preparation method of the wood-like double-layer PEDOT:PSS-CNTs / collagen thermo-electro-gel composite phase change material according to claim 1, characterized in that, The carbon nanotubes in step 1.1 are single-walled carbon nanotubes or multi-walled carbon nanotubes, wherein: the single-walled carbon nanotubes have a diameter of 1~2 nm and a length of 1~3 μm or a diameter of 1~2 nm and a length of 5~30 μm; the multi-walled carbon nanotubes have a diameter of 8~15 nm and a length of 40~60 μm.

3. The preparation method of the wood-like double-layer PEDOT:PSS-CNTs / collagen thermo-electro-gel composite phase change material according to claim 1, characterized in that, The oxidant in step 1.2 is a mixture of persulfate and iron salt, wherein: the persulfate is ammonium persulfate and sodium persulfate; and the iron salt is anhydrous ferric sulfate and ferric p-toluenesulfonate.

4. The preparation method of the wood-like double-layer PEDOT:PSS-CNTs / collagen thermo-electro-gel composite phase change material according to claim 1, characterized in that, The cellulose nanofibers in steps 2.1 and 3.1 are sodium carboxymethyl cellulose or TEMPO oxidized cellulose nanofibers.

5. The preparation method of the wood-like double-layer PEDOT:PSS-CNTs / collagen thermo-electro-gel composite phase change material according to claim 1, characterized in that, The silane coupling agent in steps 2.2 and 3.3 is γ-glycidyl etheroxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, or 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

6. The preparation method of the wood-like double-layer PEDOT:PSS-CNTs / collagen thermo-electro-gel composite phase change material according to claim 1, characterized in that, The unidirectional freezing in steps 2.3 and 3.4 is carried out at -30 to -80°C for 0.5 to 1 hour.

7. The preparation method of the wood-like double-layer PEDOT:PSS-CNTs / collagen thermo-electro-gel composite phase change material according to claim 1, characterized in that, The molecular weight of the PEG in step 3.2 is 2000~10000.

8. The preparation method of the wood-like double-layer PEDOT:PSS-CNTs / collagen thermo-electro-gel composite phase change material according to claim 1, characterized in that, The vacuum freeze-drying in step 3.4 is carried out using a vacuum freeze dryer at a pressure of 1~10 Pa and a temperature of -70~-50℃ for 24~72 h.

9. A wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material prepared by the method according to any one of claims 1 to 8.

10. The application of the wood-like double-layer PEDOT:PSS-CNTs / collagen thermoelectric gel composite phase change material according to claim 9 as a thermoelectric generator.

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