Bionic liquid surface anti-fouling solar-driven distillation membrane and its preparation method

Abstract

This invention provides a method for preparing a biomimetic liquid-surface anti-fouling solar-driven distillation membrane. The method involves mixing a film-forming material with a spinning solvent, stirring until homogeneous, and allowing it to stand to remove bubbles, obtaining an electrospinning solution. A nanofiber-based membrane is prepared from the electrospinning solution using electrospinning. A photothermal material is ultrasonically dispersed in deionized water, and then deposited onto the permeate side surface of the nanofiber-based membrane using vacuum filtration, resulting in a photothermal functional nanofiber membrane. Liquid molecules, potting compound, and film-forming solvent are mixed and electrostatically sprayed onto the feed side surface of the nanofiber-based membrane, which is then dried in an oven to obtain the biomimetic liquid-surface anti-fouling solar-driven distillation membrane. The distillation membrane provided by this invention does not rely on a traditional heat source and exhibits strong anti-fouling properties.

Description

Technical Field

[0001] This invention belongs to the field of polymer membrane separation materials, specifically relating to a biomimetic liquid surface anti-fouling solar-driven distillation membrane and its preparation method. Background Technology

[0002] To improve the anti-fouling performance of membrane distillation, based on relevant theories of surface science, researchers have constructed superwetting surfaces such as superhydrophobic, hydrophilic-hydrophobic composite, and superhydrophobic-superoleophobic surfaces to enhance the distillation membrane's tolerance to pollutants such as inorganic salts, organic matter, and surfactants. For example, CN202111154664.X discloses a method for preparing an anti-fouling wrinkled membrane distillation fiber membrane, which uses electrospinning and electrospraying to prepare a distillation fiber membrane with a double-layer structure, wherein the upper layer is a superhydrophobic layer with a beaded structure and the lower layer is a fiber structure base layer; CN202010743221.3 discloses a method for preparing a superhydrophobic multi-level nanofiber composite membrane distillation membrane, which uses electrospinning and hydrothermal growth of an oxide precursor to obtain a multi-level nanofiber membrane, and then sprays a modifying liquid to prepare a superhydrophobic multi-level nanofiber composite distillation membrane. However, the construction process of superwetting surfaces is often cumbersome and complex, and the fragility of their micro-nano structures and concave structures under continuous water flow impact and hot water splash conditions reduces the anti-fouling durability of superwetting distillation membranes, limiting the application of distillation membranes in industry. In addition, most existing distillation membranes are based on traditional heat sources (relying on industrial waste heat or residual heat), which result in high energy consumption and low economic efficiency.

[0003] In summary, a distillation membrane that does not rely on traditional heat sources and has strong anti-fouling properties, as well as its preparation method, urgently need to be developed. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a distillation membrane that does not rely on a traditional heat source and has strong anti-fouling properties;

[0005] To achieve the above and other related objectives, the present invention provides a biomimetic liquid surface anti-fouling solar-driven distillation method.

[0006] The membrane preparation method includes the following steps:

[0007] Step 1, Preparation of nanofiber-based membrane: The film-forming material is mixed with the spinning solvent, stirred evenly, and allowed to stand to remove bubbles to obtain an electrospinning solution; the electrospinning solution is added to the electrospinning device, and the nanofiber-based membrane is prepared by electrospinning.

[0008] Step 2, Preparation of photothermal nanofiber membrane: The photothermal material is ultrasonically dispersed in deionized water, and the photothermal material is deposited on the permeable side surface of the nanofiber base membrane by vacuum filtration to obtain a photothermal functional nanofiber membrane.

[0009] Step 3, Preparation of the biomimetic liquid surface anti-fouling solar-driven distillation membrane: Liquid molecules, potting compound, and film-forming solvent are mixed and sprayed onto the feed side surface of the nanofiber base membrane by electrostatic spraying. The mixture is then placed in an oven and dried to obtain the biomimetic liquid surface anti-fouling solar-driven distillation membrane; wherein,

[0010] The liquid molecules are organosilicon oil or modified organosilicon oil; the organosilicon oil is one or more of dimethyl silicone oil, diethyl silicone oil and phenyl silicone oil; the modified organosilicon oil is one or more of amino-modified silicone oil, mercapto-modified silicone oil, epoxy-modified silicone oil, alkyl-modified silicone oil and fluorine-modified silicone oil.

[0011] Preferably, it includes the following steps:

[0012] Step 1, Preparation of nanofiber-based membrane: The film-forming material and spinning solvent are mixed, stirred evenly, and allowed to stand to remove bubbles, resulting in an electrospinning solution; the electrospinning solution is added to a disposable syringe, the syringe is fixed on an electrospinning device, and the nanofiber-based membrane is prepared by electrospinning under a high voltage of 12-25KV; the electrospinning device is self-made in the laboratory; the electrospinning spacing is 10-20 cm, the spinning time is 12-24 h, the injection speed is 0.5-2.0 mL / h, the spinning temperature is 25±1℃, and the spinning humidity is 65±3%.

[0013] Step 2, Preparation of photothermal nanofiber membrane: The photothermal material is ultrasonically dispersed in deionized water, and the photothermal material is deposited on the permeable side surface of the nanofiber base membrane by vacuum filtration to obtain a photothermal functional nanofiber membrane.

[0014] Step 3, Preparation of the biomimetic liquid surface anti-fouling solar-driven distillation membrane: Liquid molecules, potting compound, and film-forming solvent are mixed and electrostatically sprayed onto the feed side surface of the nanofiber base membrane. The membrane is then placed in an 80℃ oven and dried for 3–5 hours to obtain the biomimetic liquid surface anti-fouling solar-driven distillation membrane. The electrostatic spraying is performed on an electrospinning device with a spraying voltage of 20–30 KV, a spacing of 10–20 cm, a spraying time of 5–60 min, an injection speed of 0.5–1.0 mL / h, a spraying temperature of 25±1℃, and a humidity of 65±3%.

[0015] Preferably, in step 1, the film-forming material is one or more of polyvinylidene fluoride, polyethersulfone, and polyacrylonitrile; and the spinning solvent is one or more of N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, and acetone.

[0016] Preferably, the weight ratio of the film-forming material to the spinning solvent is 1.0:5.0 to 12.5.

[0017] Preferably, in step 2, the photothermal material is graphene oxide, carbon nanotubes, nano-graphite powder, or graphene quantum dots.

[0018] One or more.

[0019] Preferably, the weight ratio of the photothermal material to deionized water is 1.0:100-500.

[0020] Preferably, the deposition amount of the photothermal material on the surface of the nanofiber-based film is 2.0–10.0 g / m. 2 .

[0021] Preferably, in step 3, the potting compound is an organosilicon potting compound or an epoxy resin potting compound; the film-forming solvent is one or more of n-hexane, butanone, acetone and ethyl acetate; and the weight ratio of the liquid molecules, potting compound and film-forming solvent is 1.0:0.5-5.0:10-20.

[0022] Preferably, the viscosity of the silicone oil is 500–5000 mm. 2 / s; the viscosity of the modified silicone oil is 300-3000 mm. 2 / s.

[0023] A biomimetic liquid surface anti-fouling solar-driven distillation membrane, prepared by the above-mentioned method, comprises a nanofiber base membrane, a photothermal material deposited on the permeation side surface of the nanofiber base membrane, and a liquid coating sprayed on the feed side of the nanofiber base membrane.

[0024] The preparation method of the biomimetic liquid surface anti-fouling solar-driven distillation membrane presented in this case has the following beneficial effects:

[0025] 1) Based on the flow characteristics of liquid molecules and the low adhesion and pollutant release characteristics of organosilicon oils, this invention prepares an anti-fouling distillation membrane based on a liquid coating. Its anti-fouling stability is much higher than that of traditional superwetting distillation membranes. Moreover, the preparation process is simple and practical, does not require micro-nano hierarchical structures, and is easy to industrialize.

[0026] 2) By combining linear liquid molecules with a network formed by potting compound, a semi-interpenetrating network structure is formed, thereby achieving a balance between the fluidity of liquid molecules and the durability of biomimetic liquid surfaces;

[0027] 3) Driven by the inexhaustible solar energy, the energy consumption of the membrane distillation process is greatly reduced. Attached Figure Description

[0028] Figure 1 Electron microscopy image of the permeate side surface of the biomimetic liquid surface anti-fouling solar-driven distillation membrane prepared in Example 1;

[0029] Figure 2 Electron microscopy image of the feed side surface of the biomimetic liquid surface anti-fouling solar-driven distillation membrane prepared in Example 1;

[0030] Figure 3 The water contact angle test diagram of the feed side surface of the biomimetic liquid surface anti-fouling solar-driven distillation membrane prepared in Example 1 is shown.

[0031] Figure 4 The graph shows the water flux and rejection rate of the biomimetic liquid surface anti-fouling solar-driven distillation membrane prepared in Example 1 as a function of time.

[0032] Figure 5 This is a schematic diagram of a biomimetic liquid surface anti-fouling solar-driven distillation membrane distillation device.

[0033] Among them, 1-permeation chamber; 2-feed chamber; 3-coagulation chamber; 4-bionic liquid surface anti-fouling solar-driven distillation membrane; 5-feed liquid; 6-simulated fluorescent lamp; 7-conductivity meter; 8-online monitoring system; 9-electronic balance. Detailed Implementation

[0034] 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.

[0035] The anti-fouling distillation membranes obtained in the following embodiments were tested and evaluated for the following technical indicators.

[0036] (1) Contact angle test: The feed side surface of the prepared anti-fouling distillation membrane 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.

[0037] (2) Permeation and separation performance: Biomimetic liquid surface anti-fouling solar-driven distillation membrane distillation device, such as Figure 5 The distillation membrane 4 prepared in this invention is located between the permeation chamber 1 and the feed chamber 2, with seawater (salt content approximately 3.5%) as the feed liquid 5 introduced into the feed chamber 2. A simulated fluorescent lamp 6 (light power density 2.0 KW / m²) is used. 2Under irradiation, the distillation membrane of this invention converts light energy into heat energy to drive the evaporation of the feed liquid 5. The generated water vapor passes through the membrane pores and the permeation chamber 1, and enters the condensation chamber 3. The condensate mass is weighed by an electronic balance 9 and recorded by an online monitoring system 8. The condensate conductivity is measured by a conductivity meter 7. The distillation membrane permeation flux is characterized by the change in condensate mass, i.e., the increase in pure water per unit time and unit membrane area; the salt rejection rate is characterized by the changes in the conductivity of the feed liquid and the condensate.

[0038] (3) Anti-scaling performance: Using seawater as feed liquid, the membrane distillation unit was continuously concentrated for 48 h in a solar-driven system to evaluate the changes in permeate flux and rejection rate of the distillation membrane.

[0039] 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.

[0040] Example 1:

[0041] A method for preparing a biomimetic liquid surface anti-fouling solar-driven distillation membrane includes the following steps:

[0042] 1. Preparation of nanofiber-based membrane: Polyvinylidene fluoride (PVDF) and N,N-dimethylformamide (NDM) were mixed, mechanically stirred at 60°C for 10 h, and allowed to stand at 60°C for 10 h to remove bubbles, resulting in a homogeneous solution for electrospinning. The spinning solution was added to a disposable syringe, which was then fixed to an electrospinning device. Nanofiber-based membranes were prepared by electrospinning. The weight ratio of PVDF to N,N-dimethylformamide was 1.0:9.0. The electrospinning conditions were: voltage 15 kV, spinning spacing 15 cm, spinning time 20 h, injection speed 0.5 mL / h, spinning temperature 25 ± 1°C, and spinning humidity 65 ± 3%.

[0043] 2. Preparation of photothermal nanofiber membrane: Carbon nanotube photothermal material was ultrasonically dispersed in deionized water. The dispersed carbon nanotubes were then deposited onto the permeable side surface of the nanofiber-based membrane using vacuum filtration. The deposition rate was controlled to be 6.0 g / m³ by adjusting the amount of dispersion added. 2 Moisture was removed in an 80℃ oven to obtain a photothermal nanofiber membrane; the weight ratio of carbon nanotube photothermal material to deionized water was 1.0:200; the electron microscope image of the prepared photothermal nanofiber membrane (i.e., the permeate side surface of the biomimetic liquid surface anti-fouling solar-driven distillation membrane) is shown below. Figure 1 As shown.

[0044] 3. Preparation of a biomimetic liquid surface anti-fouling solar-driven distillation membrane: Dimethyl silicone oil liquid molecules (viscosity 2000 mmHg) 2The mixture of dimethyl silicone oil, silicone potting compound, and hexane was electrostatically sprayed onto the feed-side surface of the nanofiber-based membrane. The membrane was then treated in an 80°C oven for 4 hours to allow the potting compound components to fully crosslink, resulting in the biomimetic liquid-surface anti-fouling solar-driven distillation membrane. The weight ratio of dimethyl silicone oil liquid molecules, silicone potting compound, and hexane was 1.0:0.5:15. The electrostatic spraying conditions were: voltage 25 KV, spinning spacing 20 cm, spinning time 15 min, injection speed 0.5 mL / h, spraying temperature 25±1°C, and spraying humidity 65±3%. The electron microscope image of the feed-side surface of the prepared biomimetic liquid-surface anti-fouling solar-driven distillation membrane is shown below. Figure 2 As shown.

[0045] Testing showed that the biomimetic liquid surface anti-fouling solar-driven distillation membrane prepared in this embodiment has a water contact angle of 132.3° on the feed side. 0 ( Figure 3 The treatment effect on seawater is as follows: water flux is 2.80 Lm. -2 h -1 The rejection rate was 99.99%. After 48 hours of continuous concentration operation, the flux did not change significantly, and the rejection rate did not decrease. Figure 4 ); and carbon nanotube photothermal film without liquid coating (after 48 h of operation, the water flux increased from 2.81 Lm). -2 h -1 It dropped to 1.21 Lm -2 h -1 Compared to the previous version, the anti-scaling performance and operational stability have been significantly improved.

[0046] Example 2:

[0047] This invention provides a method for preparing a biomimetic liquid surface anti-fouling solar-driven distillation membrane, comprising the following steps:

[0048] 1. Preparation of nanofiber-based membrane: The steps are the same as step 1 in Example 1.

[0049] 2. Preparation of photothermal nanofiber membrane: Graphene oxide photothermal material was ultrasonically dispersed in deionized water. The dispersed graphene oxide was then deposited onto the permeable side surface of the nanofiber-based membrane using vacuum filtration. The deposition rate was controlled to be 6.0 g / m³ by adjusting the amount of dispersion added. 2 The moisture was removed in an 80℃ oven to obtain a photothermal functional nanofiber membrane; the weight ratio of graphene oxide photothermal material to deionized water was 1.0:200.

[0050] 3. Preparation of a biomimetic liquid surface anti-fouling solar-driven distillation membrane: Phenyl silicone oil liquid molecules (viscosity 1500 mmHg) 2The mixture of dimethyl silicone oil, silicone potting compound, and n-hexane is electrostatically sprayed onto the feed side surface of the nanofiber base membrane and then treated in an 80°C oven for 4 h to allow the potting compound components to fully crosslink, resulting in the biomimetic liquid surface anti-fouling solar-driven distillation membrane. The weight ratio of dimethyl silicone oil liquid molecules, silicone potting compound, and solvent n-hexane is 1.0:0.5:15. The electrostatic spraying process conditions are: voltage 25 KV, spinning spacing 20 cm, spinning time 15 min, injection speed 0.5 mL / h, spraying temperature 25±1°C, and spraying humidity 65±3%.

[0051] Testing showed that the biomimetic liquid surface anti-fouling solar-driven distillation membrane prepared in this embodiment has a water contact angle of 135.5° on the feed side. 0 The seawater treatment effect is as follows: water flux is 2.78 Lm. -2 h -1 The rejection rate was 99.99%. After 48 hours of continuous concentration operation, the flux did not change significantly, and the rejection rate did not decrease. In contrast, the water flux of the graphene oxide photothermal film without a liquid coating decreased from 2.79 Lm after 48 hours of operation. -2 h -1 It dropped to 1.22 Lm -2 h -1 Compared to the previous version, the anti-scaling performance and operational stability have been significantly improved.

[0052] Example 3:

[0053] This invention provides a method for preparing a biomimetic liquid surface anti-fouling solar-driven distillation membrane, comprising the following steps:

[0054] 1. Preparation of nanofiber-based membrane: Polyacrylonitrile and N,N-dimethylformamide were mixed, mechanically stirred at 60℃ for 10 h, and allowed to stand at 60℃ for 10 h to remove bubbles, resulting in a homogeneous solution for electrospinning. The spinning solution was added to a disposable syringe, which was then fixed to an electrospinning device. Nanofiber-based membranes were prepared by electrospinning. The weight ratio of polyacrylonitrile film-forming material to solvent N,N-dimethylformamide was 1.0:9.0. The electrospinning process conditions were: voltage 20 kV, spinning spacing 15 cm, spinning time 20 h, injection speed 0.5 mL / h, spinning temperature 25±1℃, and spinning humidity 65±3%.

[0055] 2. Preparation of photothermal nanofiber membrane: The steps are the same as step 2 in Example 1;

[0056] 3. Preparation of biomimetic liquid surface anti-fouling solar-driven distillation membrane: The steps are the same as step 3 in Example 1.

[0057] Testing showed that the biomimetic liquid surface anti-fouling solar-driven distillation membrane prepared in this embodiment has a water contact angle of 131.8° on the feed side. 0 The seawater treatment effect is as follows: water flux is 2.75 Lm. -2 h -1 The rejection rate was 99.99%. After 48 hours of continuous concentration operation, the flux did not change significantly, and the rejection rate did not decrease. In contrast, the water flux of the uncoated polyacrylonitrile photothermal film decreased from 2.77 Lm after 48 hours of operation. -2 h -1 It dropped to 1.24 Lm -2 h -1 Compared to the previous version, the anti-scaling performance and operational stability have been significantly improved.

[0058] Example 4:

[0059] This invention provides a method for preparing a biomimetic liquid surface anti-fouling solar-driven distillation membrane, comprising the following steps:

[0060] 1. Preparation of nanofiber-based membrane: The steps are the same as step 1 in Example 3;

[0061] 2. Preparation of photothermal nanofiber membrane: The steps are the same as step 2 in Example 2;

[0062] 3. Preparation of biomimetic liquid surface anti-fouling solar-driven distillation membrane: The steps are the same as step 3 in Example 2;

[0063] Testing showed that the biomimetic liquid surface anti-fouling solar-driven distillation membrane prepared in this embodiment has a water contact angle of 132.3° on the feed side. 0 The seawater treatment effect is as follows: water flux is 2.76 Lm. -2 h -1 The rejection rate was 99.99%. After 48 hours of continuous concentration operation, the flux did not change significantly, and the rejection rate did not decrease. In contrast, the water flux of the uncoated polyacrylonitrile photothermal film (which, after 48 hours of operation, decreased from 2.75 Lm) was significantly reduced. -2 h -1 It dropped to 1.20 Lm -2 h -1 Compared to the previous version, the anti-scaling performance and operational stability have been significantly improved.

[0064] Example 5:

[0065] This invention provides a method for preparing a biomimetic liquid surface anti-fouling solar-driven distillation membrane, comprising the following steps:

[0066] 1. Preparation of nanofiber-based membrane: Polyethersulfone and N,N-dimethylformamide were mixed, mechanically stirred at 60℃ for 10 h, and allowed to stand at 60℃ for 10 h to remove bubbles, resulting in a homogeneous solution for electrospinning. The spinning solution was added to a disposable syringe, which was then fixed to an electrospinning device. Nanofiber-based membrane was prepared by electrospinning. The weight ratio of polyethersulfone film-forming material to solvent N,N-dimethylformamide was 1.0:9.0. The electrospinning process conditions were: voltage 20 kV, spinning spacing 15 cm, spinning time 20 h, injection speed 0.5 mL / h, spinning temperature 25±1℃, and spinning humidity 65±3%.

[0067] 2. Preparation of photothermal nanofiber membrane: The steps are the same as step 2 in Example 1;

[0068] 3. Preparation of biomimetic liquid surface anti-fouling solar-driven distillation membrane: The steps are the same as step 3 in Example 1.

[0069] Testing showed that the biomimetic liquid surface anti-fouling solar-driven distillation membrane prepared in this embodiment has a water contact angle of 134.0° on the feed side. 0 The seawater treatment effect is as follows: water flux is 2.77 Lm. -2 h -1 The rejection rate was 99.99%. After 48 hours of continuous concentration operation, the flux did not change significantly, and the rejection rate did not decrease. In contrast, the water flux of the polyethersulfone photothermal film without a liquid coating decreased from 2.78 Lm after 48 hours of operation. -2 h -1 It dropped to 1.22 Lm -2 h -1 Compared to the previous version, the anti-scaling performance and operational stability have been significantly improved.

[0070] Example 6:

[0071] This invention provides a method for preparing a biomimetic liquid surface anti-fouling solar-driven distillation membrane, comprising the following steps:

[0072] 1. Preparation of nanofiber-based membrane: The steps are the same as step 1 in Example 5;

[0073] 2. Preparation of photothermal nanofiber membrane: The steps are the same as step 2 in Example 2;

[0074] 3. Preparation of biomimetic liquid surface anti-fouling solar-driven distillation membrane: The steps are the same as step 3 in Example 2;

[0075] Testing showed that the water contact angle on the feed side surface of the anti-fouling solar-driven distillation membrane prepared in this embodiment was 134.4°. 0 The seawater treatment effect is as follows: water flux is 2.78 Lm. -2 h -1The rejection rate was 99.99%. After 48 hours of continuous concentration operation, the flux did not change significantly, and the rejection rate did not decrease. In contrast, the water flux of the polyethersulfone photothermal film without a liquid coating decreased from 2.76 Lm after 48 hours of operation. -2 h -1 It dropped to 1.22 Lm -2 h -1 Compared to the previous version, the anti-scaling performance and operational stability have been significantly improved.

[0076] 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 method for preparing a biomimetic liquid surface anti-fouling solar-driven distillation membrane, characterized in that, It comprises the following steps: Step 1, preparation of nanofiber-based membrane: the film-forming material is mixed with the spinning solvent, stirred uniformly and left to stand for defoaming to obtain an electrospinning solution; The electrospinning solution is added to the electrospinning device, and a nanofiber-based membrane is prepared by electrospinning method under the high voltage of 12-25KV; Step 2, preparation of photo-thermal nanofiber membrane: the photo-thermal material is ultrasonically dispersed in deionized water, and the photo-thermal material is deposited on the permeation side surface of the nanofiber-based membrane by vacuum filtration to obtain a photo-thermal functional nanofiber membrane; Step 3, preparation of biomimetic liquid surface anti-fouling solar-driven distillation membrane: the liquid molecules, potting adhesive and membrane-forming solvent are mixed and sprayed on the feed side surface of the nanofiber-based membrane by electrostatic spraying, and then placed in an oven for heating and drying to obtain the biomimetic liquid surface anti-fouling solar-driven distillation membrane; wherein, The liquid molecules are silicone oil or modified silicone oil; the silicone oil is one or more of dimethyl silicone oil, diethyl silicone oil and phenyl silicone oil; the modified silicone oil is one or more of amino-modified silicone oil, mercapto-modified silicone oil, epoxy-modified silicone oil, alkyl-modified silicone oil and fluorine-modified silicone oil.

2. The method of claim 1, wherein the method is performed by the steps of: It comprises the following steps: Step 1, preparation of nanofiber-based membrane: the film-forming material is mixed with the spinning solvent, stirred uniformly and left to stand for defoaming to obtain an electrospinning solution; The electrospinning solution is added to the electrospinning device, and a nanofiber-based membrane is prepared by electrospinning method under the high voltage of 12-25KV; Step 2, preparation of photo-thermal nanofiber membrane: the photo-thermal material is ultrasonically dispersed in deionized water, and the photo-thermal material is deposited on the permeation side surface of the nanofiber-based membrane by vacuum filtration to obtain a photo-thermal functional nanofiber membrane; Step 3, preparation of biomimetic liquid surface anti-fouling solar-driven distillation membrane: the liquid molecules, potting adhesive and membrane-forming solvent are mixed and sprayed on the feed side surface of the nanofiber-based membrane by electrostatic spraying, and then placed in an oven for heating and drying to obtain the biomimetic liquid surface anti-fouling solar-driven distillation membrane.

3. A method of making a biomimetic liquid surface antifouling solar-driven distillation membrane according to claim 1 or 2, characterized in that, In step 1, the film-forming material is one or more of polyvinylidene fluoride, polyether sulfone and polyacrylonitrile; the spinning solvent is one or more of N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, N-methyl pyrrolidone and acetone.

4. The method of claim 3, wherein the method further comprises the step of: The weight ratio of the film-forming material to the spinning solvent is 1.0:5.0-12.

5.

5. The method for preparing the biomimetic liquid surface anti-fouling solar-driven distillation membrane according to claim 1, 2, or 4, characterized in that, In step 2, the photo-thermal material is one or more of graphene oxide, carbon nanotube, nano-graphite powder and graphene quantum dot.

6. The method of claim 5, wherein the method further comprises the step of: The weight ratio of the photo-thermal material to deionized water is 1.0:100-500.

7. The method of claim 6, wherein the method further comprises the step of: The photothermal material is deposited on the surface of the nanofiber-based film in an amount of 2.0-10.0 g / m 2 .

8. The method of claim 1, 2, 4, 6 or 7, wherein the method further comprises: In step 3, the potting adhesive is silicone potting adhesive or epoxy resin potting adhesive; the membrane-forming solvent is one or more of n-hexane, butanone, acetone and ethyl acetate; the weight ratio of the liquid molecules, potting adhesive and membrane-forming solvent is 1.0:0.5-5.0:10-20.

9. The preparation method of the biomimetic liquid surface anti-fouling solar-driven distillation membrane according to claim 8, characterized in that, viscosity of the organic silicone oil is 500 to 5,000 mm 2 viscosity of the modified organic silicone oil is 300 to 3,000 mm 2 viscosity of the modified organic silicone oil is 300 to 3,000 mm 10. A biomimetic liquid surface anti-fouling solar-driven distillation membrane, characterized in that, A biomimetic liquid surface anti-fouling solar-driven distillation membrane prepared by the method of claim 9, comprising a nanofiber-based membrane, a photothermal material deposited on the permeate side surface of the nanofiber-based membrane, and a liquid coating sprayed on the feed side of the nanofiber-based membrane.

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