Dual-drive superhydrophilic photothermal film and its preparation method

Abstract

This invention provides a method for preparing a dual-drive superhydrophilic photothermal film. The method involves treating a film-forming material in an oven, removing it, mixing it with an organic solvent, stirring to dissolve, allowing it to stand to degas, obtaining a spinning solution, and preparing a nanofiber spun base film using electrospinning. A photothermal conversion material, a superhydrophilic modifier, and deionized water are mixed and ultrasonically treated to obtain a uniform dispersion. The photothermal conversion material and superhydrophilic modifier are deposited onto the surface of the nanofiber spun base film using a vacuum filtration process. After drying and cross-linking, a superhydrophilic photothermal conversion nanofiber film is obtained. The film is then subjected to a first hot-pressing process to improve its integrity, folded, and a second hot-pressing process to solidify, resulting in the dual-drive superhydrophilic photothermal film. This invention also provides a dual-drive superhydrophilic photothermal film. The dual-drive superhydrophilic photothermal film provided by this invention has the advantage of not being limited by natural or climatic conditions.

Description

Technical Field

[0001] This invention belongs to the field of polymer membrane separation materials, specifically relating to a dual-drive superhydrophilic photothermal membrane and its preparation method. Background Technology

[0002] With population growth and deepening economic globalization, water scarcity and water environment degradation have become pressing issues for sustainable development. Extracting valuable freshwater resources from saline sources such as seawater and brine using membrane separation technology is a crucial approach to addressing the current water crisis. Currently, nanofiltration and reverse osmosis technologies are widely used for desalination; however, their high operating pressure and sensitivity to salt concentration significantly limit their ability to treat high-concentration brine. Compared to traditional nanofiltration and reverse osmosis membrane separation technologies, membrane distillation technology utilizes the vapor pressure difference caused by the temperature difference across the membrane, allowing water vapor to diffuse from the high-temperature side to the low-temperature side and condense there, thus achieving efficient separation of non-volatile components such as salts. It offers numerous advantages, including low operating pressure and temperature, insensitivity to salt concentration, and high separation efficiency. However, membrane distillation technology is energy-intensive and only meaningful when using industrial waste heat or residual heat as a heat source, greatly limiting its widespread application.

[0003] To address the issue of high energy consumption, solar-driven membrane distillation technology has attracted widespread attention. This technology utilizes photothermal conversion materials to convert solar energy into thermal energy and confines the heat to the evaporation interface to minimize heat loss. For example, CN201811288437.4 discloses a porous photothermal membrane with antibacterial properties, which uses vacuum filtration of carbon nanotube dispersion onto the membrane surface to form a self-floating double-layer porous photothermal membrane; CN201910804893.8 discloses a porous photothermal membrane with anti-salting properties, which uses a nitriding reaction to load TiNx with a plasmon resonance effect onto the surface of a TiO2 / Ti porous membrane, thereby improving light absorption. However, it should be noted that although the total amount of solar energy reaching the Earth's surface is large, its energy density is very low, and it is greatly limited by natural conditions such as day and night, season, altitude, and latitude, as well as climatic conditions such as cloudy, rainy, and overcast skies.

[0004] In summary, a novel method for preparing high-performance photothermal films that is not limited by natural or climatic conditions is urgently needed. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a novel high-performance photothermal film that is not limited by natural and climatic conditions;

[0006] To achieve the above and other related objectives, this invention provides a method for preparing a dual-drive superhydrophilic photothermal film, comprising the following steps:

[0007] Step 1, Preparation of nanofiber spinning base film: The film-forming material is placed in an oven for hot drying, taken out, mixed with an organic solvent, stirred and dissolved, allowed to stand to remove bubbles, and a uniform spinning solution is obtained. The nanofiber spinning base film is prepared by electrospinning.

[0008] Step 2, Preparation of superhydrophilic photothermal conversion nanofiber membrane: Photothermal conversion material, superhydrophilic modifier and deionized water are mixed and ultrasonically treated to obtain a uniform dispersion. The dispersion is then filtered using a vacuum filtration process to deposit the photothermal conversion material and superhydrophilic modifier onto the surface of the nanofiber spinning base membrane. After drying and baking crosslinking, a superhydrophilic photothermal conversion nanofiber membrane is obtained.

[0009] Step 3, Preparation of the dual-drive superhydrophilic photothermal film: The superhydrophilic photothermal conversion nanofiber film is subjected to a first hot pressing to improve its integrity, folded, and then hot-pressed a second time to fix it, thus obtaining the dual-drive superhydrophilic photothermal film.

[0010] Preferably, it includes the following steps:

[0011] Step 1, Preparation of nanofiber spun base film: The film-forming material is placed in an oven and dried at 60-80℃ for 20-24 hours. After removal, it is mixed with an organic solvent, stirred to dissolve, and allowed to stand to remove bubbles, resulting in a homogeneous spinning solution. The nanofiber spun base film is prepared by electrospinning under a high voltage difference of 10-30KV. The electrospinning device is self-made in the laboratory and is consistent with commercially available devices. The electrospinning spacing is 15-20cm, the spinning time is 12-20h, the injection speed is 0.5-1.0mL / h, the spinning temperature is 20±1℃, and the spinning humidity is 30±3%.

[0012] Step 2, Preparation of superhydrophilic photothermal conversion nanofiber membrane: Photothermal conversion material, superhydrophilic modifier and deionized water are mixed and ultrasonically treated to obtain a uniform dispersion. The dispersion is then filtered using a vacuum filtration process to deposit the photothermal conversion material and superhydrophilic modifier onto the surface of the nanofiber spinning base membrane. After drying and baking crosslinking, a superhydrophilic photothermal conversion nanofiber membrane is obtained.

[0013] Step 3, Preparation of the dual-drive superhydrophilic photothermal film: The superhydrophilic photothermal conversion nanofiber film is subjected to a first hot pressing to improve its integrity, folded, and then hot-pressed a second time to fix it, thus obtaining the dual-drive superhydrophilic photothermal film; wherein, the temperature of the first hot pressing is 120-160℃ and the duration is 10-60 min; the temperature of the second hot pressing is 100-140℃ and the duration is 5-20 min.

[0014] Preferably, in step 1, the film-forming material is one or more of polyvinylidene fluoride, polysulfone, polyethersulfone, and polyacrylonitrile; the organic solvent is one or more of N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, acetone, and ethyl acetate; and the weight ratio of the film-forming material to the organic solvent is 1.0:4.0 to 12.0.

[0015] Preferably, in step 2, the photothermal conversion material is one or more of carbon nanotubes, graphene oxide, nano-graphite powder, copper sulfide nanoparticles, and graphene quantum dots.

[0016] Preferably, the superhydrophilic modifier is prepared by free radical polymerization. The polymerization process is as follows: under a protective atmosphere, hydrophilic monomers and crosslinking monomers are reacted at room temperature for 20-24 hours in an acetic acid or hydrochloric acid solution with a pH of 2.5-4.0 under the action of an initiator and a chain transfer agent. After the reaction is complete, the superhydrophilic modifier is obtained by precipitation-dissolution purification.

[0017] The hydrophilic monomer is one or more of acrylic acid, methacrylic acid, acrylamide, and isopropylacrylamide;

[0018] The crosslinking monomer is one or more of methacryloyloxypropyltrimethoxysilane and methacryloyloxypropyltriethoxysilane;

[0019] The initiator includes an oxidizing component and a reducing component, and the initiator is one or more of the following: ammonium persulfate-sodium metabisulfite, ammonium persulfate-sodium bisulfite, potassium persulfate-sodium metabisulfite, and potassium persulfate-sodium bisulfite.

[0020] The chain transfer agent is one or more of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane and 2-mercaptoethanol;

[0021] The protective atmosphere is a nitrogen or argon atmosphere; the precipitant used for precipitation-dissolution purification is methanol or ethanol.

[0022] Preferably, in step 2, the weight ratio of the oxidizing component to the reducing component in the initiator is 1:0.9-1.1; the weight ratio of the hydrophilic monomer, crosslinking monomer, initiator, chain transfer agent and solvent is 10-30:5-10:0.5-1.5:1-3:100.

[0023] Preferably, in step 2, the weight ratio of the photothermal conversion material, the superhydrophilic modifier, and the deionized water is 0.1–1.0: 0.5–3.0: 100.

[0024] Preferably, in step 2, the drying temperature is 60-80℃ and the drying time is 6-12h; the baking temperature is 100-120℃ and the baking time is 1-3h.

[0025] Preferably, the deposition amount of the photothermal conversion material on the nanofiber membrane surface is 2.0–10.0 g / m². 2 .

[0026] A dual-drive superhydrophilic photothermal film, prepared using the above-described method.

[0027] The preparation method of the dual-drive superhydrophilic photothermal film presented in this case has the following beneficial effects:

[0028] 1) Based on the capillary water conduction effect and the interfacial evaporation characteristics of the fan-shaped folded structure of the superhydrophilic nanofiber membrane, this invention prepares a photothermal film with environmental thermal driving characteristics, thereby avoiding the unreliability of solar-driven photothermal films caused by natural and climatic conditions.

[0029] 2) The photothermal film of the present invention has dual-drive characteristics of environmental heat and photothermal energy, which endow it with high permeability, thereby reducing the adverse effects of low solar energy density on membrane flux. Attached Figure Description

[0030] Figure 1 Electron microscopy image of the permeation side surface of the dual-drive superhydrophilic photothermal film prepared in Example 1;

[0031] Figure 2 Electron micrograph of the feed side surface of the dual-drive superhydrophilic photothermal film prepared in Example 1;

[0032] Figure 3 The water contact angle test diagram of the feed side surface of the dual-drive superhydrophilic photothermal film prepared in Example 1 is shown.

[0033] Figure 4 Infrared spectrum of the feed side surface of the dual-drive superhydrophilic photothermal film prepared in Example 2;

[0034] Figure 5 A schematic diagram of the structure of a dual-drive superhydrophilic photothermal film water flux testing device;

[0035] Among them, 1-photothermal film; 2-simulated fluorescent lamp; 3-electronic balance; 4-polystyrene foam board; 5-container; 6-plexiglass cover. Detailed Implementation

[0036] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0037] The superhydrophilic, high-flux photothermal films obtained in the following embodiments were tested and evaluated for the following technical indicators.

[0038] (1) Contact angle test: The feed side surface of the prepared dual-drive superhydrophilic photothermal film was fixed on a glass slide with the feed side facing upward and placed on a contact angle measuring instrument for testing. 5 μL of deionized water was added, and 5 different test points were taken for each sample. The average value was taken as the final contact angle of the sample.

[0039] (2) Permeation and Separation Performance: A schematic diagram of the photothermal film water flux testing device is shown below. Figure 5 The photothermal film 1 prepared in this invention is placed on a polystyrene foam board 4. Seawater (with a salt content of approximately 3.5%) is used as the feed liquid and placed in a container 5. The polystyrene foam board 4 floats on the surface of the feed liquid. The photothermal film 1 and the feed liquid are connected by a superhydrophilic membrane strip (any membrane with superhydrophilic properties). A simulated fluorescent lamp 2 (light power density 1.0 KW / m²) is used. 2 Under irradiation, the photothermal film of the present invention converts light energy into heat energy to drive the evaporation of the feed liquid entering the membrane pores. The generated water vapor passes through the membrane pores and condenses on the surface of the plexiglass cover 6. The mass of the condensate is equal to the mass reduction of the feed liquid, and is weighed by the electronic balance 3. The water flux of the photothermal film is characterized by the change in the mass of the condensate, that is, the increase in the amount of condensate per unit time and per unit projection membrane area. The salt rejection rate is characterized by the change in the conductivity of the feed liquid and the condensate.

[0040] Unless otherwise specified, all reagents used in the following examples of the present invention are of analytical grade and were purchased from China National Pharmaceutical Group Shanghai Chemical Reagent Co., Ltd.

[0041] Example 1:

[0042] This invention provides a method for preparing a dual-drive superhydrophilic photothermal film, comprising the following steps:

[0043] 1. Preparation of nanofiber spun base film: Polyvinylidene fluoride (PVDF) was placed in an oven and dried at 60℃ for 24 h. 8.0 parts of PVDF were mixed with solvents: 57.6 parts of N,N-dimethylformamide and 14.4 parts of acetone. The mixture was dissolved by mechanical stirring and allowed to stand to remove bubbles to obtain a homogeneous spinning solution. Nanofiber spun base film was prepared by electrospinning. The electrospinning process conditions were: voltage 13KV, spinning spacing 15cm, spinning time 20h, injection speed 0.5mL / h, spinning temperature 20±1℃, and spinning humidity 30±3%.

[0044] 2. Preparation of superhydrophilic photothermal conversion nanofiber membrane: 0.8 parts carbon nanotubes, 1.0 parts superhydrophilic modifier, and 100 parts deionized water were mixed and ultrasonically treated to obtain a uniform dispersion. The carbon nanotubes and superhydrophilic modifier were deposited on the surface of the nanofiber spinning substrate membrane using a vacuum filtration process. The membrane was dried at 60℃ for 10 h and then baked at 120℃ for 1 h for crosslinking to obtain the superhydrophilic photothermal conversion nanofiber membrane. The deposition amount of carbon nanotubes on the membrane surface was 5.0 g / m³. 2 The polymerization process of the superhydrophilic modifier is as follows: 15 parts of acrylic acid, 6 parts of methacryloxypropyltrimethoxysilane, 0.5 parts of ammonium persulfate, 0.5 parts of sodium metabisulfite, and 1 part of 3-mercaptopropyltrimethoxysilane are dissolved in 100 parts of pH 2.5 acetic acid solution. The reaction is carried out under a nitrogen atmosphere at room temperature for 24 hours. After the reaction is complete, the superhydrophilic modifier is purified three times by methanol precipitation and dissolution in pH 2.5 acetic acid solution to obtain the superhydrophilic modifier.

[0045] 3. Preparation of the dual-drive superhydrophilic photothermal film: The above-mentioned superhydrophilic photothermal conversion nanofiber membrane was subjected to a first hot-pressing treatment at 160℃ for 10 min to improve its integrity, and then folded and subjected to a second hot-pressing treatment at 100℃ for 15 min to obtain the dual-drive superhydrophilic photothermal film; the electron microscope image of the permeable side surface of the photothermal film is shown below. Figure 1 As shown in the electron microscope image, the feed side surface is as follows. Figure 2 As shown.

[0046] Testing showed that the water contact angle on the feed side surface of the dual-drive superhydrophilic photothermal film prepared in this embodiment was 3.2°. Figure 3 The treatment effect on seawater is as follows: under light conditions, the water flux is 2.50 Lm. -2 h -1 The retention rate was 99.99%; under no-light conditions, the water flux was 1.21 L / m³. -2 h -1 The retention rate is 99.99%; compared with traditional carbon nanotube-deposited polyvinylidene fluoride photothermal films (under illumination conditions, the water flux is 1.25 Lm). -2 h -1 Under conditions of no light, the water flux is 0.22 L / m². -2 h -1 Compared to the previous version, both penetration and operational reliability have been significantly improved.

[0047] Example 2:

[0048] 1. Preparation of nanofiber spinning base film: The steps are the same as step 1 in Example 1.

[0049] 2. Preparation of superhydrophilic photothermal conversion nanofiber membrane: 0.8 parts of graphene oxide, 1.0 part of superhydrophilic modifier, and 100 parts of deionized water were mixed and ultrasonically treated to obtain a uniform dispersion. Graphene oxide and the superhydrophilic modifier were deposited on the surface of a nanofiber spinning substrate membrane using vacuum filtration. The membrane was dried at 60℃ for 10 h and then baked at 120℃ for 1 h to obtain the superhydrophilic photothermal conversion nanofiber membrane. The deposition amount of graphene oxide on the membrane surface was 6.0 g / m³. 2 The polymerization process of the superhydrophilic modifier is as follows: 15 parts of acrylamide, 6 parts of methacryloxypropyltrimethoxysilane, 0.5 parts of ammonium persulfate, 0.5 parts of sodium metabisulfite, and 1 part of 3-mercaptopropyltrimethoxysilane are dissolved in 100 parts of pH 2.5 acetic acid solution. The reaction is carried out at room temperature under a nitrogen atmosphere for 24 hours. After the reaction is complete, the superhydrophilic modifier is purified three times by methanol precipitation and pH 2.5 acetic acid solution dissolution to obtain the superhydrophilic modifier.

[0050] 3. Preparation of the dual-drive superhydrophilic photothermal film: The steps are the same as step 3 in Example 1; the infrared spectrum of the feed side surface of the prepared photothermal film is shown below. Figure 4 As shown.

[0051] Testing showed that the water contact angle on the feed side surface of the dual-drive superhydrophilic photothermal film prepared in this embodiment was 3.8°, and its seawater treatment effect was as follows: under illumination, the water flux was 2.55 Lm. -2 h -1 The retention rate was 99.99%; under no-light conditions, the water flux was 1.23 L / m³. -2 h -1 The retention rate is 99.99%; compared with traditional graphene oxide-deposited polyvinylidene fluoride photothermal film (under illumination conditions, the water flux is 1.28 Lm). -2 h -1 Under conditions of no light, the water flux is 0.24 L / m². -2 h -1 Compared to the previous version, both penetration and operational reliability have been significantly improved.

[0052] Example 3:

[0053] 1. Preparation of nanofiber spun base film: The film-forming material polyacrylonitrile was treated in an oven at 60℃ for 24h. 8.0 parts of polyacrylonitrile and 72.0 parts of N,N-dimethylformamide were mixed, dissolved by mechanical stirring, and allowed to stand to remove bubbles to obtain a homogeneous spinning solution. The nanofiber spun base film was prepared by electrospinning. The electrospinning process conditions were: voltage 18KV, spinning spacing 20cm, spinning time 12h, injection speed 1.0mL / h, spinning temperature 20±1℃, and spinning humidity 30±3%.

[0054] 2. Preparation of superhydrophilic photothermal conversion nanofiber membrane: The steps are the same as step 2 in Example 1.

[0055] 3. Preparation of dual-drive superhydrophilic photothermal film: The steps are the same as step 3 in Example 1.

[0056] Testing showed that the water contact angle on the feed side of the dual-drive superhydrophilic photothermal film prepared in this embodiment was 3.1°, and its seawater treatment effect was as follows: under illumination, the water flux was 2.56 Lm. -2 h -1 The retention rate was 99.99%; under no-light conditions, the water flux was 1.27 L / m³. -2 h -1 The retention rate is 99.99%. Compared to traditional carbon nanotube-deposited polyacrylonitrile photothermal films (under illumination conditions, the water flux is 1.28 L / m²), this method achieves a water flux of 1.28 L / m². -2 h -1 Under conditions of no light, the water flux is 0.25 L / m². -2 h -1 Compared to the previous version, both penetration and operational reliability have been significantly improved.

[0057] Example 4:

[0058] 1. Preparation of nanofiber spinning base film: The steps are the same as step 1 in Example 3;

[0059] 2. Preparation of superhydrophilic photothermal conversion nanofiber membrane: The steps are the same as step 2 in Example 2;

[0060] 3. Preparation of dual-drive superhydrophilic photothermal film: The steps are the same as step 3 in Example 1.

[0061] Testing showed that the water contact angle on the feed side surface of the superhydrophilic, high-flux photothermal film prepared in this embodiment was 3.0°, and its seawater treatment effect was as follows: under illumination, the water flux was 2.58 Lm. -2 h -1 The retention rate was 99.99%; under no-light conditions, the water flux was 1.28 L / m³. -2 h -1 The retention rate is 99.99%. Compared to traditional graphene oxide-deposited polyacrylonitrile photothermal films (under illumination conditions, the water flux is 1.29 L / m²),... -2 h -1 Under conditions of no light, the water flux is 0.26 L / m². -2 h -1 Compared to the previous version, both penetration and operational reliability have been significantly improved.

[0062] Example 5:

[0063] 1. Preparation of nanofiber spun base film: The film-forming material polyethersulfone was treated in an oven at 60℃ for 24h. 8.0 parts of polyethersulfone and 80.0 parts of N,N-dimethylformamide were mixed, dissolved by mechanical stirring, and allowed to stand to remove bubbles to obtain a homogeneous spinning solution. The nanofiber spun base film was prepared by electrospinning. The electrospinning process conditions were: voltage 15KV, spinning spacing 15cm, spinning time 13h, injection speed 0.8mL / h, spinning temperature 20±1℃, and spinning humidity 30±3%.

[0064] 2. Preparation of superhydrophilic photothermal conversion nanofiber membrane: The steps are the same as step 2 in Example 1;

[0065] 3. Preparation of dual-drive superhydrophilic photothermal film: The steps are the same as step 3 in Example 1.

[0066] Testing showed that the water contact angle on the feed side of the dual-drive superhydrophilic photothermal film prepared in this embodiment was 3.3°, and its seawater treatment effect was as follows: under illumination, the water flux was 2.56 Lm. -2 h -1 The retention rate was 99.99%; under no-light conditions, the water flux was 1.24 L / m³. -2 h -1 The retention rate is 99.99%. Compared to traditional carbon nanotube-deposited polyethersulfone photothermal films (under illumination conditions, the water flux is 1.24 Lm³), this method achieves a water flux of 1.24 Lm³. -2 h -1 Under conditions of no light, the water flux is 0.23 Lm. -2 h -1 Compared to the previous version, both penetration and operational reliability have been significantly improved.

[0067] Example 6

[0068] 1. Preparation of nanofiber spinning base film: The steps are the same as step 1 in Example 5.

[0069] 2. Preparation of superhydrophilic photothermal conversion nanofiber membrane: The steps are the same as step 2 in Example 2.

[0070] 3. Preparation of dual-drive superhydrophilic photothermal film: The steps are the same as step 3 in Example 1.

[0071] Testing showed that the water contact angle on the feed side of the dual-drive superhydrophilic photothermal film prepared in this embodiment was 3.0°, and its seawater treatment effect was as follows: under illumination, the water flux was 2.59 Lm. -2 h -1 The retention rate was 99.99%; under no-light conditions, the water flux was 1.26 L / m³. -2 h -1 The retention rate is 99.99%; compared with traditional graphene oxide-deposited polyethersulfone photothermal film (under illumination conditions, the water flux is 1.23 Lm).-2 h -1 Under conditions of no light, the water flux is 0.20 Lm. -2 h -1 Compared to the previous version, both penetration and operational reliability have been significantly improved.

[0072] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A preparation method of a dual-drive type super-hydrophilic light-thermal film, characterized in that, Comprising the following steps, Step 1, preparation of nanofiber spinning base film: the film-forming material is heated in an oven, taken out, mixed with an organic solvent, stirred and dissolved, and left to degas to obtain a uniform spinning solution, and a nanofiber spinning base film is prepared by electrospinning; Step 2, preparation of super-hydrophilic light-heat conversion nanofiber film: the light-heat conversion material, super-hydrophilic modifier and deionized water are mixed and uniformly dispersed by ultrasonic treatment, the dispersion liquid is filtered by vacuum filtration process to deposit the light-heat conversion material and super-hydrophilic modifier on the surface of the nanofiber spinning base film, and the super-hydrophilic light-heat conversion nanofiber film is obtained after drying and cross-linking by baking; Step 3, preparation of double-drive super-hydrophilic light-heat film: the super-hydrophilic light-heat conversion nanofiber film is improved in integrity by one-time hot pressing, folded, and shaped by two-time hot pressing to obtain the double-drive super-hydrophilic light-heat film; wherein, In step 1, the film-forming material is one or more of polyvinylidene fluoride, polysulfone, polyethersulfone and polyacrylonitrile; the organic solvent is one or more of N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, N-methyl pyrrolidone, acetone and ethyl acetate; the weight ratio of the film-forming material to the organic solvent is 1.0:4.0-12.0; The super-hydrophilic modifier is prepared by free radical polymerization, and the polymerization process is as follows: in a protective atmosphere, hydrophilic monomers and cross-linking monomers are reacted at room temperature for 20-24 hours in a solution of acetic acid or hydrochloric acid with a pH of 2.5-4.0, under the action of an initiator and a chain transfer agent, and after the reaction is completed, the super-hydrophilic modifier is obtained by precipitation-dissolution purification; wherein, The hydrophilic monomer is one or more of acrylic acid, methacrylic acid, acrylamide and isopropyl acrylamide; the cross-linking monomer is one or more of methacryloyloxypropyl trimethoxysilane and methacryloyloxypropyl triethoxysilane. Comprising the following steps, 2. The preparation method of the dual-drive super-hydrophilic photo-thermal film according to claim 1, characterized in that Step 1, preparation of nanofiber spinning base film: the film-forming material is heated in an oven at 60-80℃ for 20-24 hours, taken out, mixed with an organic solvent, stirred and dissolved, and left to degas to obtain a uniform spinning solution, and a nanofiber spinning base film is prepared by electrospinning under the traction of a high voltage difference of 10-30 KV; Step 2, preparation of super-hydrophilic light-heat conversion nanofiber film: the light-heat conversion material, super-hydrophilic modifier and deionized water are mixed and uniformly dispersed by ultrasonic treatment, the dispersion liquid is filtered by vacuum filtration process to deposit the light-heat conversion material and super-hydrophilic modifier on the surface of the nanofiber spinning base film, and the super-hydrophilic light-heat conversion nanofiber film is obtained after drying and cross-linking by baking; Step 3, preparation of double-drive super-hydrophilic light-heat film: the super-hydrophilic light-heat conversion nanofiber film is improved in integrity by one-time hot pressing, folded, and shaped by two-time hot pressing to obtain the double-drive super-hydrophilic light-heat film; wherein, the temperature of the one-time hot pressing is 120-160℃, and the time length is 10-60 minutes; the temperature of the two-time hot pressing is 100-140℃, and the time length is 5-20 minutes. ​ 3.The method of claim 2, wherein the method comprises the steps of: coating a first layer of a first material on a substrate; coating a second layer of a second material on the first layer; and coating a third layer of a third material on the second layer. The photo-thermal conversion material in step 2 is one or more of carbon nanotubes, graphene oxide, nano-graphite powder, copper sulfide nanoparticles and graphene quantum dots. 4.The method of claim 3, wherein the method comprises the steps of: coating a first layer of a first material on a substrate; coating a second layer of a second material on the first layer; and coating a third layer of a third material on the second layer. The initiator used in the preparation of the super-hydrophilic modifier comprises an oxidizing component and a reducing component, and the initiator is one or more of ammonium persulfate-sodium pyrosulfite, ammonium persulfate-sodium bisulfite, potassium persulfate-sodium pyrosulfite and potassium persulfate-sodium bisulfite; The chain transfer agent is one or more of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane and 2-mercaptoethanol; The protective atmosphere is nitrogen or argon atmosphere; and the precipitant used for the precipitation-dissolution purification is methanol or ethanol. 5.The method for preparing the dual-driven super-hydrophilic light-heat film according to claim 4, characterized in that, In step 2, the weight ratio of the oxidizing component to the reducing component in the initiator is 1:0.9-1.1; and the weight ratio of the hydrophilic monomer, the cross-linking monomer, the initiator, the chain transfer agent and the solvent is 10-30:5-10:0.5-1.5:1-3:

100. 6.The method for preparing the dual-driven super-hydrophilic light-heat film according to claim 5, characterized in that, In step 2, the weight ratio of the photo-thermal conversion material, the super-hydrophilic modifier and the deionized water is 0.1-1.0:0.5-3.0:

100. 7.The method of claim 6, wherein the method further comprises the step of: coating the first and second superhydrophilic light-to-heat conversion films with a protective layer. In step 2, the drying temperature is 60-80℃, and the drying time is 6-12 h; and the baking temperature is 100-120℃, and the baking time is 1-3 h. 8.The method of claim 7, wherein the method comprises the steps of: coating a first layer of the first material on a substrate; coating a second layer of the second material on the first layer; and coating a third layer of the third material on the second layer. The amount of the light-heat conversion material deposited on the surface of the nanofiber membrane is 2.0-10.0 g / m 2 .

9. A dual drive type super-hydrophilic photo-thermal film, characterized in that, The double-driven super-hydrophilic photo-thermal film prepared by the preparation method of any one of claims 1-8. The photo-thermal conversion material in step 2 is one or more of carbon nanotubes, graphene oxide, nano-graphite powder, copper sulfide nanoparticles and graphene quantum dots. The initiator used in the preparation of the super-hydrophilic modifier comprises an oxidizing component and a reducing component, and the initiator is one or more of ammonium persulfate-sodium pyrosulfite, ammonium persulfate-sodium bisulfite, potassium persulfate-sodium pyrosulfite and potassium persulfate-sodium bisulfite; The chain transfer agent is one or more of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane and 2-mercaptoethanol; The protective atmosphere is nitrogen or argon atmosphere; and the precipitant used for the precipitation-dissolution purification is methanol or ethanol. In step 2, the weight ratio of the oxidizing component to the reducing component in the initiator is 1:0.9-1.1; and the weight ratio of the hydrophilic monomer, the cross-linking monomer, the initiator, the chain transfer agent and the solvent is 10-30:5-10:0.5-1.5:1-3:

100. In step 2, the weight ratio of the photo-thermal conversion material, the super-hydrophilic modifier and the deionized water is 0.1-1.0:0.5-3.0:

100. In step 2, the drying temperature is 60-80℃, and the drying time is 6-12 h; and the baking temperature is 100-120℃, and the baking time is 1-3 h. The double-driven super-hydrophilic photo-thermal film prepared by the preparation method of any one of claims 1-8.

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