WO2021253286A1

WO2021253286A1 - Preparation method for flexible optical/electrical-thermal dual-response phase-change cloth

Info

Publication number: WO2021253286A1
Application number: PCT/CN2020/096596
Authority: WO
Inventors: 李昂; 王戈; 袁福根
Original assignee: 苏州科技大学
Priority date: 2020-06-17
Filing date: 2020-06-17
Publication date: 2021-12-23
Also published as: JP2022542619A; JP7226834B2

Abstract

A flexible optical/electrical-thermal dual-response phase-change cloth, which uses a carbon fiber cloth as a base and comprises a metal organic framework material grown on carbon fibers, as well as a phase-change energy storage material adsorbed in the metal organic framework material. A preparation method therefor comprises: (1) synthesizing a metal organic framework in-situ on a carbon fiber cloth to obtain a carbon fiber cloth @MOFs carrier; and (2) adsorbing a phase-change material by using solution impregnation to obtain a flexible optical/electrical-thermal dual-response phase change cloth. By means of the organic combination of a substrate cloth, a phase-change core material, and MOFs, the described flexible optical/electrical-thermal dual-response phase-change cloth effectively improves the deficiencies of an organic phase-change material in which optical/electrical response cannot be achieved, as well as the thermal deformation and high temperature leakage thereof. The flexible optical/electrical-thermal dual-response phase-change cloth has high optical/electrical-thermal conversion capabilities, strong structural integrity, high cycle stability, and excellent shear resistance.

Description

Method for preparing flexible light/electricity-heat dual response phase change cloth

Technical field

The invention belongs to the field of nanocomposite materials and composite phase change materials, and specifically relates to a method for preparing a flexible light/electricity-heat dual response phase change cloth.

Background technique

Renewable energy plays an important role in replacing the excessive development and use of fossil fuels. Among them, solar energy, as a rich and lasting renewable energy, has achieved significant application effects in the field of photoelectric conversion and photocatalysis. However, the above-mentioned solar energy system is still limited by the problem of low energy conversion efficiency. If phase change materials that can store and release heat at the same time are applied to the field of light-to-heat conversion, the utilization rate of solar energy will be effectively improved. However, most phase change materials have poor light absorbing ability and have the problem of thermally induced deformation. In addition, the intermittent problem of sunlight leads to intermittent heat. Therefore, it is still a challenge to realize the continuous supply of thermal energy while ensuring the good mechanical properties of the photothermal system. It is of great significance to develop optical/electric-thermal dual response phase change materials with excellent mechanical properties.

As a flexible material with excellent light absorption and electrical conductivity, carbon cloth can provide a continuous electron transmission channel for the system and promote the continuous supply of heat. However, carbon cloth cannot be directly used as a light/electricity-thermal dual response phase change material, which is mainly limited by the fact that carbon cloth cannot support a phase change core material with heat storage and transfer performance.

Summary of the invention

The purpose of the present invention is to overcome the shortcomings of the prior art and provide a flexible optical/electric-thermal dual-response phase change cloth, which is based on carbon fiber cloth and includes a metal-organic framework material grown on the carbon fiber and adsorbed on the Phase change materials in metal organic framework materials. On the one hand, the surface tension, capillary force or hydrogen bonding force of the MOFs pores can effectively encapsulate the phase change core material in the pores, thereby achieving high core material loading and high phase change enthalpy of the composite phase change material. On the other hand, the multi-level pore structure of carbon cloth @MOFs promotes the concentration of sunlight on the surface of the carbon cloth, enhances the capture of the light source, and thereby improves the light-to-heat conversion efficiency. At the same time, the flexible carbon cloth substrate provides a continuous electron transmission channel for the system to realize the rapid conversion of the phase change material from electrical energy to thermal energy under low excitation voltage. In addition, MOFs increase the wettability of the carrier material, and PCM and carbon cloth achieve a chain effect through MOFs to enhance the shear resistance of the material.

The phase change material suitable for this application can be any combination of one or more of polyols, fatty acids, and linear alkanes. Wherein, the polyols include but are not limited to polyethylene glycol (with an average molecular weight of 1000-20000), neopentyl glycol, pentaerythritol, etc.; the fatty acids include but are not limited to stearic acid, myristic acid, palmitic acid , Lauric acid, pentadecanoic acid, capric acid, sebacic acid, etc.; the linear alkanes include, but are not limited to, n-hexadecane, n-decane, n-tetradecane, n-octadecane and the like.

Another object of the present invention is to provide a method for preparing the above-mentioned flexible optical/electric-thermal dual-response phase change cloth, which includes the following steps:

(1) In-situ synthesis of metal organic framework on carbon fiber cloth to obtain carbon fiber cloth @MOFs carrier;

(2) Vacuum the carbon fiber cloth@MOFs carrier prepared in step 1 at 40～200℃ for 2～10h, and then place it in the solution of phase change material, where the mass of the carbon fiber cloth@MOFs carrier and the phase change material in the solution The ratio of mass is more than 1:9, and then it is dried under the condition of higher than the phase change temperature of the phase change material to obtain a carbon cloth@MOFs-based composite phase change material.

In some embodiments, the following method is used for in-situ synthesis: the carbon fiber cloth is immersed in 30 mL of concentrated HNO ₃ solution, reacted at 100°C for 3 hours, and then vacuum dried for 24 hours to obtain an activated carbon fiber cloth; the activated carbon fiber cloth is immersed in In DMF or an aqueous solution containing soluble metal salt and organic carboxylic acid ligand, the molar ratio of soluble metal salt to organic carboxylic acid ligand is 2:1; react in a 50 mL reactor at 100-200°C for 12 to 48 hours, It was filtered and washed with N,N-dimethylformamide (DMF) three times to remove by-products and impurities, and dried at 60-150°C for 4 to 48 hours to obtain carbon cloth@MOFs carrier material.

The soluble metal salts suitable for the synthesis of the metal organic framework of the present invention include but are not limited to: zinc nitrate, zinc chloride, zinc sulfate, zinc acetate, ferric nitrate, ferric chloride, ferric sulfate, ferric acetate, cobalt nitrate, cobalt chloride, Cobalt sulfate, cobalt acetate, copper nitrate, copper chloride, copper sulfate, copper acetate, chromium nitrate, chromium chloride, chromium sulfate, chromium acetate, zirconium nitrate, zirconium chloride, zirconium sulfate, zirconium acetate, nickel nitrate, nickel sulfate , Nickel acetate, nickel chloride, aluminum nitrate, aluminum sulfate, aluminum acetate, aluminum chloride, manganese nitrate, manganese chloride, manganese sulfate, manganese acetate, titanium sulfate, titanium nitrate, titanium chloride, etc. Species; organic carboxylic acid ligands include, but are not limited to: terephthalic acid, 2-nitroterephthalic acid, 2-sulfonic acid terephthalic acid, 2-aminoterephthalic acid and other one or more kind.

The beneficial effects of the present invention are:

The advantages of the present invention are: the flexible light/electricity-heat dual response phase change fabric through the organic combination of base fabric, phase change core material and MOF, effectively improves the poor light absorption ability, low electrical conductivity, and thermally induced properties of organic phase change materials. The shortcomings of deformation and easy leakage. It has the advantages of high optical/electrical heat conversion ability, strong structural integrity, high cycle stability and excellent shear resistance, and has broad application prospects.

1) The multi-level pore structure of carbon cloth @MOFs promotes the direct collection of sunlight on the surface of the carbon cloth, enhances the capture of the light source, and effectively improves the light-to-heat conversion efficiency of the material;

2) As an electron transmission channel, carbon cloth can realize the rapid conversion of electric energy to heat energy. At the same time, the flexible substrate of carbon cloth ensures the continuity and structural integrity of the material, and expands the application range of the light/electricity-thermal dual response phase change material;

3) Multi-level pore structure MOFs are used as energy storage units, using the surface tension of the pores, capillary force or hydrogen bond force to effectively encapsulate the phase change core material in the pores, effectively solving the core problem that carbon cloth materials cannot store energy;

4) The preparation method provided by the present invention is simple, has good optical/electric thermal performance, strong structural integrity, diversified core material selection, good cycle stability, and is suitable for large-scale production.

Description of the drawings

Figure 1 is the SEM image of the carbon cloth @MOFs carrier obtained in Example 1 of the present invention.

Figure 2 is the XRD pattern of the carbon cloth @MOFs carrier obtained in Example 1 of the present invention.

Figure 3 is an XRD pattern of the carbon cloth@MOFs carrier loaded with PEG2000 obtained in Example 1 of the present invention.

Fig. 4 is a DSC chart of the carbon cloth@MOFs carrier loaded with PEG2000 obtained in Example 1 of the present invention.

Fig. 5 is the light-heat temperature change curve of the carbon cloth@MOFs carrier loaded with PEG2000 obtained in Example 1 of the present invention.

Fig. 6 is the electrothermal temperature change curve of the carbon cloth@MOFs carrier loaded with PEG2000 obtained in Example 1 of the present invention.

FIG. 7 is a comparison diagram of the shear resistance of the carbon cloth@MOFs carrier loaded with PEG2000 obtained in Example 1 of the present invention.

detailed description

The technical solution of the present invention will be further described below in conjunction with specific embodiments.

Implementation case 1

(1) Preparation of carbon cloth@MOF-5 carrier material:

Soak 2cm*3cm carbon cloth in 30mL concentrated HNO ₃ solution, react at 100℃ for 3h, then vacuum dry for 24h to obtain activated carbon cloth; place the activated carbon cloth (2cm*3cm) with 0.743g hexahydrate nitric acid Zinc and 0.207g terephthalic acid in 25mL DMF solvent, and put it into a 50mL reactor. After reacting at 120°C for 10 hours, it was filtered and washed with DMF three times, and dried at 80°C for 24 hours to obtain a carbon cloth@MOF-5 carrier material.

(2) Preparation of composite phase change material:

The carbon cloth@MOF-5 (2cm*3cm) carrier material prepared above was evacuated at 120°C for 8 hours to completely open the pores of the substrate. Dissolve 0.18 g PEG2000 in 20 mL ethanol to obtain a uniform phase change material solution. Then the carrier material is put into the prepared phase change material solution, and then placed in an oven at 80° C. to dry for 24 hours to obtain a PEG2000/carbon cloth@MOF-5 light/electricity-thermal dual response phase change material.

It can be observed from the SEM image in Figure 1 that MOF-5 grows uniformly on the surface of the carbon fiber, so the porous structure has a strong potential for adsorbing core material molecules. All the characteristic peaks of MOF-5 can be observed from the XRD results in Fig. 2. Combined with the SEM scanning electron microscope results in Fig. 1, it is confirmed that this solution can be used to prepare carbon cloth@MOF-5 carrier materials, and carbon cloth@MOF-5 The carrier adsorbs PEG2000 into its multi-stage pores. At the same time, after the adsorption is saturated, the surface continues to adsorb part of PEG2000. Therefore, from the XRD results of the flexible phase change cloth in Figure 3, the significant characteristic peaks of PEG2000 can be observed, which confirms the use of this experiment. The project successfully obtained a flexible phase change cloth with excellent crystalline properties. The DSC test result shown in Figure 4 shows that the melting temperature of the flexible phase change cloth is 61.6°C, the melting enthalpy is 116.5J/g, the melting temperature is 31.5°C, and the melting enthalpy is 112.3J/g. The photothermal performance test results of Figure 5 show that the flexible phase change cloth can be heated to 138°C within 300s under the light intensity of 1 Sun (simulated standard sunlight). The electrothermal performance test results of Figure 6 show that the flexible phase change cloth can be The low excitation voltage of 2.0V can quickly realize heat storage and conversion within 42s. At the same time, the shear strength test results of Figure 7 show that the shear strength of the flexible conductive phase change cloth is 61.5% higher than that of pure carbon cloth. The above results It strongly proves that the flexible optical/electric-thermal dual-response phase change fabric prepared by the present invention has excellent optical/electric thermal conversion and storage characteristics and good mechanical properties, and effectively solves the inability of carbon fabric materials to store energy and the light absorption ability of phase change materials Poor, low conductivity, heat-induced deformation, and easy leakage are the core issues. At the same time, the provided preparation method is simple and suitable for large-scale production.

Implementation case 2

(1) Preparation of carbon cloth@IRMOF-3 carrier material:

Soak 2cm*3cm carbon cloth in 30mL concentrated HNO ₃ solution, react for 3h at 100℃, then vacuum dry for 24h to obtain activated carbon cloth; place the activated carbon cloth (2cm*3cm) in containing 0.892g hexahydrate nitric acid Zinc, 0.181g 2-aminoterephthalic acid in 30mL DMF solvent, and put it into a 50mL reactor. After reacting at 100°C for 24 hours, it was filtered and washed with DMF three times, and dried at 80°C for 24 hours to obtain a carbon cloth@IRMOF-3 carrier material.

(2) Preparation of composite phase change material:

0.25g of the carbon cloth@IRMOF-3 (2cm*3cm) carrier material prepared above was evacuated at 120°C for 8h to completely open the pores of the substrate. Dissolve 0.25 g of octadecanoic acid in 20 mL of ethanol to obtain a uniform phase change material solution. Then the carrier material is put into the prepared phase change material solution, and then placed in an oven at 80° C. to dry for 24 hours to obtain the octadecanoic acid/carbon cloth@IRMOF-3 light/electricity-thermal dual response phase change material.

The test results show that the flexible conductive phase change cloth can heat up to 102°C in 300s under the light intensity of 1Sun (simulated standard sunlight), and realize the heat storage and conversion in 58s under the excitation voltage of 3.2V, and at the same time Its shear strength is 46.2% higher than that of pure carbon cloth.

Implementation case 3

(1) Preparation of carbon cloth @MIL-101(Cr)-NH ₂ carrier material:

Soak 2cm*3cm carbon cloth in 30mL concentrated HNO ₃ solution, react at 100℃ for 3h, then vacuum dry for 24h to obtain activated carbon cloth; place the activated carbon cloth (2cm*3cm) with 1.6g nonahydrate nitric acid Chromium, 0.72 g of 2-aminoterephthalic acid and 0.4 g of NaOH in 30 mL of deionized water were placed in a 50 mL reactor. After reacting at 150°C for 12 hours, it was filtered and washed with DMF three times, and dried at 80°C for 24 hours to obtain a carbon cloth@MIL-101(Cr)-NH ₂ carrier material.

(2) Preparation of composite phase change material:

The carbon cloth @MIL-101(Cr)-NH ₂ (2cm*3cm) carrier material prepared above was evacuated at 120° C. for 8 hours to completely open the pores of the substrate. 0.20 g of octadecanoic acid was dissolved in 20 mL of ethanol to obtain a uniform phase change material solution. Then disperse the carrier material into the prepared phase change material solution, and then place it in an oven at 80°C to dry for 24 hours to obtain octadecanoic acid/carbon cloth @MIL-101(Cr)-NH ₂ photo/electric-thermal dual response phase Change material.

The test results show that the flexible conductive phase change cloth can heat up to 116°C in 300s under the light intensity of 1Sun (simulated standard sunlight), and realize the heat storage and conversion in 69s under the excitation voltage of 2.8V, and at the same time Its shear strength is 52.6% higher than that of pure carbon cloth.

Claims

A flexible light/electricity-thermal dual response phase change cloth, which is characterized by comprising a carbon fiber cloth, a metal organic framework material grown on the carbon fiber, and a phase change material adsorbed in the metal organic framework material.
The flexible light/electricity-thermal dual response phase change cloth according to claim 1, wherein the phase change material is selected from one or more of polyols, fatty acids, and linear alkanes in any combination.
The flexible light/electricity-thermal dual response phase change cloth according to claim 2, wherein the polyols include polyethylene glycol (with an average molecular weight of 1000-20000), neopentyl glycol, pentaerythritol, etc.; The fatty acids include stearic acid, myristic acid, palmitic acid, lauric acid, pentadecanoic acid, capric acid, sebacic acid, etc.; the linear alkanes include: n-hexadecane, n-decane, n-decane Tetradecane, n-octadecane, etc.
The method for preparing flexible optical/electrical-thermal dual response phase change cloth according to claim 1, characterized in that it comprises the following steps:

(1) In-situ synthesis of metal organic framework on carbon fiber cloth to obtain carbon fiber cloth @MOFs carrier;

(2) Vacuum the carbon fiber cloth@MOFs carrier prepared in step 1 at 40～200℃ for 2～10h, and then place it in the solution of phase change material, where the mass of the carbon fiber cloth@MOFs carrier and the phase change material in the solution The ratio of mass is more than 1:9, and then it is dried under the condition of higher than the phase change temperature of the phase change material to obtain a carbon cloth@MOFs-based composite phase change material.
The preparation method according to claim 4, wherein the step (1) is specifically:

Soak the carbon fiber cloth in 30mL of concentrated HNO 3 solution, react at 100°C for 3 hours, then vacuum dry for 24 hours to obtain activated carbon fiber cloth; immerse the activated carbon fiber cloth in DMF or an aqueous solution containing soluble metal salts and organic carboxylic acid ligands , Wherein the molar ratio of the soluble metal salt to the organic carboxylic acid ligand is 2:1; react in a 50mL reactor at 100-200℃ for 12～48h, filter and wash with N,N-dimethylformamide (DMF) Three times, remove by-products and impurities, and dry at 60-150°C for 4 to 48 hours to obtain carbon cloth@MOFs carrier material.