Dual-wettability atmospheric water collecting membrane and preparation method thereof

Abstract

The invention discloses a dual-wettability atmospheric water collecting membrane and a preparation method thereof, and belongs to the technical field of composites.According to the technical scheme, a hydrophobic material and a hydrophilic material which are remarkably different are used for constructing the dual-wettability atmospheric water collecting membrane, and the dual-wettability atmospheric water collecting membrane is prepared; the dual-wettability atmospheric water collection membrane has good air permeability and filterability, efficient atmospheric water collection is achieved by utilizing the properties that the surface of the hydrophilic material promotes atmospheric water capture and the surface of the hydrophobic material promotes surface renewal, meanwhile, on one hand, the contact surface of water mist and the internal structure of the fiber membrane can be increased so as to improve the water absorption efficiency, and on the other hand, the air permeability and filterability are improved. On the other hand, small particles can be separated and filtered to improve the atmospheric water collecting efficiency.

Description

Technical Field

[0001] The invention relates to the field of composite materials, and in particular to a double-wetting atmospheric water collection membrane and a preparation method thereof. Background Art

[0002] As the global water shortage problem becomes increasingly serious, finding new ways to obtain water resources has become one of the key research directions. In nature, atmospheric water (including fog, dew, etc.) is a potential water resource with a wide distribution and relatively stable replenishment. However, due to the low concentration of atmospheric water and low collection efficiency, how to efficiently collect and utilize atmospheric water has become a research hotspot.

[0003] Traditional atmospheric water collection membranes mostly use a single hydrophilic or hydrophobic material. Hydrophilic membranes can absorb water, but are easy to lose and difficult to effectively retain water; while single hydrophobic materials are difficult to absorb water, reducing the overall water collection efficiency. Therefore, developing a collection membrane with dual wettability to achieve simultaneous and efficient water adsorption and retention functions has become a research focus in current water collection technology. Summary of the invention

[0004] The main purpose of the present invention is to propose a double-wettable atmospheric water collection membrane and a preparation method thereof, aiming to provide a new double-wettable atmospheric water collection membrane for efficiently collecting atmospheric water and alleviating the problem of water shortage.

[0005] To achieve the above object, the present invention proposes a double wettability atmospheric water collection membrane for collecting atmospheric water, wherein the material of the double wettability atmospheric water collection membrane includes a hydrophobic material and a hydrophilic material.

[0006] In one embodiment, the hydrophobic material accounts for (50-90)% by weight of the material of the dual wettability atmospheric water collection membrane.

[0007] In one embodiment, the hydrophobic material is polystyrene, and the number average molecular weight of the polystyrene is 15w-20w.

[0008] In one embodiment, the hydrophilic material is thermoplastic polyurethane.

[0009] In one embodiment, the dual wettability atmospheric water collection membrane further comprises a filler, and the filler comprises a conductive medium.

[0010] The present invention provides a method for preparing the dual-wetting atmospheric water collection membrane as described above, characterized in that it comprises the following preparation steps:

[0011] S10, dissolving and mixing the hydrophobic material and the hydrophilic material to obtain a mixed solution;

[0012] S20, electrostatically spinning the mixed solution, collecting it into a membrane, and drying it to obtain a dual-wetting atmospheric water collection membrane.

[0013] In one embodiment, step S10 includes:

[0014] S101, mixing a hydrophobic material and a hydrophilic material with a solvent to obtain a first solution;

[0015] S102, mixing the conductive medium with a solvent to obtain a second solution;

[0016] S103, mixing the first solution and the second solution to obtain a mixed solution.

[0017] In one embodiment, in step S101, the solvent includes dimethylacetamide.

[0018] In one embodiment, in step S102, the conductive medium includes barium titanate.

[0019] In the technical solution of the present invention, the present invention uses hydrophobic materials and hydrophilic materials with significant differences to construct a double-wettable atmospheric water collection membrane. The double-wettable atmospheric water collection membrane has good air permeability and filterability, and utilizes the surface of the hydrophilic material to promote atmospheric water capture, and the surface of the hydrophobic material to promote surface renewal, thereby achieving efficient atmospheric water collection. At the same time, on the one hand, the contact area between water mist and the internal structure of the fiber membrane can be increased to improve the water absorption efficiency, and on the other hand, tiny particles can be separated and filtered to improve the quality of collected atmospheric water. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0021] Figure 1 Schematic diagram of the electrospinning device of the flat-plate collector used in the embodiment experiment;

[0022] Figure 2 is a cold field scanning electron microscope schematic diagram of the dual wettability atmospheric water collection membrane prepared in Example 1;

[0023] Figure 3 is a cold field scanning electron microscope schematic diagram of the dual wettability atmospheric water collection membrane prepared in Example 2;

[0024] Figure 4 is a schematic diagram of a cold field scanning electron microscope of the dual wettability atmospheric water collection membrane prepared in Example 3;

[0025] Figure 5 It is a schematic diagram of a water collection platform constructed to test the water collection capacity of the double wettability atmospheric water collection membrane prepared in the embodiment.

[0026] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0027] To make the purpose, technical scheme and advantages of the embodiment of the present invention clearer, the technical scheme in the embodiment of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiment, it is carried out according to the normal conditions or the conditions recommended by the manufacturer. If the reagents or instruments used do not specify the manufacturer, they are all conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes, taking "A and / or B" as an example, including scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, the technical schemes between the various embodiments can be combined with each other, but must be based on the ability of ordinary technicians in the field to achieve. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that the combination of such technical solutions does not exist, and is not within the scope of protection required by the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present invention.

[0028] As the global water shortage problem becomes increasingly serious, finding new ways to obtain water resources has become one of the key research directions. In nature, atmospheric water (including fog, dew, etc.) is a potential water resource with a wide distribution and relatively stable replenishment. However, due to the low concentration of atmospheric water and low collection efficiency, how to efficiently collect and utilize atmospheric water has become a research hotspot.

[0029] Traditional atmospheric water collection membranes mostly use a single hydrophilic or hydrophobic material. Hydrophilic membranes can absorb water, but are easy to lose and difficult to effectively retain water; while single hydrophobic materials are difficult to absorb water, reducing the overall water collection efficiency. Therefore, developing a collection membrane with dual wettability to achieve simultaneous and efficient water adsorption and retention functions has become a research focus in current water collection technology.

[0030] In view of this, to achieve the above-mentioned purpose, the present invention proposes a double wettability atmospheric water collection membrane for collecting atmospheric water, wherein the material of the double wettability atmospheric water collection membrane comprises a hydrophobic material and a hydrophilic material, and a double wettability atmospheric water collection membrane is constructed by combining the hydrophobic material and the hydrophilic material, wherein the double wettability atmospheric water collection membrane has good air permeability and filterability, and the surface of the hydrophilic material is used to promote atmospheric water capture, and the surface of the hydrophobic material promotes the property of surface renewal, so that double wettability (i.e., having both hydrophobic and hydrophilic properties) can be achieved. This characteristic enables the membrane to efficiently adsorb water molecules when collecting atmospheric water, and to avoid rapid loss of water, thereby improving water collection efficiency. In the process of atmospheric water collection, the double wettability structure helps to quickly adsorb water and retain water, thereby improving the collection effect, the hydrophobic region prevents water loss, and the hydrophilic region adsorbs water.

[0031] It can be understood that the surface renewal property refers to the ability to restore the surface to a near-initial state through a certain mechanism when a physical or chemical process occurs on the surface of a material. In atmospheric water capture technology, hydrophilic materials are used to attract and absorb moisture from the air, while hydrophobic materials are used to promote surface renewal, that is, to help remove the absorbed moisture so that the material can effectively absorb new moisture again.

[0032] Specifically, in the atmospheric water collection system, when the hydrophilic material absorbs water, if the surface cannot be renewed in time (i.e., release the absorbed water), the material will gradually reach a saturated state and its water absorption efficiency will be greatly reduced. At this time, the role of hydrophobic materials is particularly important. Hydrophobic materials can cause water to condense quickly in the form of droplets and roll off, leaving a dry surface ready for the next water absorption.

[0033] In some embodiments, the mass proportion of the hydrophobic material in the mixed material is (50-90)%, within this range, the overall hydrophobicity of the membrane is ensured (reducing water loss), and an appropriate amount of hydrophilic sites are provided for adsorbing water. An appropriate proportion of hydrophilic materials helps to efficiently adsorb water in the atmosphere, while sufficient hydrophobic materials ensure the stable structure and long-term water retention of the membrane. The combination within this mass ratio range achieves a balance in terms of water absorption and anti-loss.

[0034] In some embodiments, the hydrophobic material is polystyrene, and the number average molecular weight of the polystyrene is 15w~20w. Polystyrene with a molecular weight of 15w~20w is selected as the hydrophobic material, so that the finally obtained double-wetting atmospheric water collection membrane has good hydrophobicity and mechanical strength, which is convenient for electrospinning film formation.

[0035] Polystyrene is a common hydrophobic material with good mechanical properties. The appropriate molecular weight makes it easy to form a stable hydrophobic layer during the film formation process, maintaining the structural integrity and stability of the film.

[0036] In some embodiments, the hydrophilic material is thermoplastic polyurethane.

[0037] It should be noted that thermoplastic polyurethane has good hydrophilicity and flexibility, can effectively adsorb water molecules and improve the water collection efficiency of the membrane. At the same time, its flexibility can improve the durability and adaptability of the membrane in practical applications, enhance the membrane's water absorption performance and resistance to mechanical deformation, and is suitable for water collection.

[0038] In some embodiments, the dual-wetting atmospheric water collection membrane further includes a filler, and the filler includes a conductive medium. The introduction of the conductive medium into the material can further enhance the capture ability of water molecules by utilizing the electrostatic effect. Through these improvements, the water capture and retention ability of the collection membrane can be greatly improved under the premise of low-cost and scalable preparation, providing a feasible new way to solve the problem of water shortage.

[0039] It is understandable that water molecules in the air usually carry a trace charge, and the conductive medium can improve the electrostatic properties of the membrane, thereby improving the adsorption efficiency of water molecules. The conductive medium can also enhance the thermal conductivity of the membrane, helping the water molecules to condense faster.

[0040] The present invention provides a method for preparing the dual-wetting atmospheric water collection membrane as described above, characterized in that it comprises the following preparation steps:

[0041] S10, dissolving and mixing the hydrophobic material and the hydrophilic material to obtain a mixed solution;

[0042] S20, electrostatically spinning the mixed solution, collecting it into a membrane, and drying it to obtain a dual-wetting atmospheric water collection membrane.

[0043] It should be noted that electrospinning technology can produce a membrane with a porous structure, which is beneficial to increase the surface area of ​​the membrane and enhance the water adsorption capacity, and the drying step can ensure the structural stability of the membrane.

[0044] Moreover, electrospinning can form a fibrous structure, greatly increasing the specific surface area of ​​the membrane and enhancing its water absorption. After drying, the solvent residue can be removed, making the membrane structure more stable and maintaining its double wetting characteristics.

[0045] In the above steps, the mixed solution is electrospinned to prepare a microscopic fiber structure with dual wettability, which can further increase the specific surface area of ​​the membrane and improve its water adsorption performance.

[0046] In one embodiment, step S10 includes:

[0047] S101, mixing a hydrophobic material and a hydrophilic material with a solvent to obtain a first solution;

[0048] Furthermore, the solvent includes dimethylacetamide.

[0049] It can be understood that dimethylacetamide is a good solvent with polarity, which can dissolve a variety of polymer materials, make the hydrophobic material and the hydrophilic material evenly dispersed, form a uniform first solution, ensure the uniform composition of the membrane during the spinning process, and ensure the consistency of the membrane's performance.

[0050] S102, mixing the conductive medium with a solvent to obtain a second solution;

[0051] Since the conductive medium is evenly distributed in the membrane, its electrostatic adsorption effect can be maximized, so that the membrane can effectively capture water molecules in the air in practical applications and improve water collection efficiency.

[0052] Furthermore, the conductive medium includes barium titanate, which is a common ferroelectric material with a high dielectric constant, good dielectric properties and pyroelectric effect. In this embodiment, when it is used as a conductive medium or as a filler in certain composite materials, the performance of the dual wettability and conductive film is improved.

[0053] S103, mixing the first solution and the second solution to obtain a mixed solution.

[0054] In this step, the first solution and the second solution are mixed so that the conductive medium of the first solution is evenly distributed in the membrane, thereby improving the overall conductivity of the membrane and enhancing the adsorption capacity of water molecules.

[0055] Multi-step mixing can ensure the uniform distribution of each material, avoid inconsistent membrane performance due to uneven material distribution, and improve the water absorption and conductivity of the membrane. In this step, multi-step mixing is used to ensure that the hydrophobic, hydrophilic materials and the conductive medium are evenly dispersed, thereby obtaining a membrane with good dual wettability and conductivity.

[0056] The present invention can also provide a water collector, which includes the double-wettable atmospheric water collection membrane as described in any one of the above items or the double-wettable atmospheric water collection membrane obtained by the preparation method of the double-wettable atmospheric water collection membrane as described in any one of the above items. The water collector includes the beneficial effects of the above-mentioned double-wettable atmospheric water collection membrane, so they will not be described one by one.

[0057] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments and drawings. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0058] Example 1

[0059] A dual-wetting atmospheric water collection membrane, the preparation steps of the collection membrane are as follows:

[0060] Weigh a certain amount of polystyrene (PS) and thermoplastic polyurethane (TPU) powders, mix them in a mass ratio of 1:1, add dimethylacetamide (DMAC) solvent, stir and dissolve them at 70° C. for 4 hours, and prepare a first solution with a mass fraction of 20 wt %;

[0061] Weigh a certain amount of barium titanate (BaTiO3) powder, add dimethylacetamide (DMAC) solvent, stir at 60°C for 1 hour, and prepare a second solution with a mass fraction of 5wt%;

[0062] The first solution and the second solution were mixed in a mass ratio of 5:1, stirred and dissolved at 60° C. for 30 minutes to prepare a mixed solution with a mass fraction of 17.5 wt %, wherein the mass fraction of barium titanate in the mixed solute was 4.76 wt %.

[0063] Using an electrospinning device equipped with a flat-plate collector (see Figure 1 ) is prepared, the mixed solution is injected into a 15mL syringe with a needle size of 21G, the syringe is fixed on the propeller on one side of the flat fiber receiver, the propulsion speed is set to 1mL / h, and the distance between the injection pump nozzle and the surface of the fiber receiver is 10cm. The voltage of the positive pressure spinning system of the high-voltage electric field is +14kV, the power of the negative pressure spinning system is -3kV, the flat fiber collector is 10cm long, 10cm wide, and 2mm thick. The preparation environment is 24°C and 35% humidity. The mixed solution is injected into the high-voltage electric field from the energized injection pump nozzle. Polystyrene and thermoplastic polyurethane undergo large deformation under the action of stable electrostatic force stretching, and the organic solvent evaporates at the same time. Finally, the resin is collected into a film by the energized fiber collector in the form of fibers. After the electrospinning is completed, it needs to be dried in an oven for 6 hours to completely remove the residual solvent. Finally, a double-wetting atmospheric water collection membrane of polystyrene and thermoplastic polyurethane is obtained. The quantitative amount of the obtained double-wetting atmospheric water collection membrane is 20g / m 2 .

[0064] Example 2

[0065] A dual-wetting atmospheric water collection membrane, the preparation steps of the collection membrane are as follows:

[0066] Weigh a certain amount of polystyrene (PS) and thermoplastic polyurethane (TPU) powders, mix them in a mass ratio of 7:3, add dimethylacetamide (DMAC) solvent, stir and dissolve them at 80° C. for 4 hours, and prepare a first solution with a mass fraction of 20 wt %;

[0067] A certain amount of barium titanate (BaTiO3) powder was weighed, and dimethylacetamide (DMAC) solvent was added, and stirred at 60°C for 1 hour to prepare a second solution with a mass fraction of 5wt%.

[0068] The first solution and the second solution were mixed in a mass ratio of 5:1, stirred and dissolved at 60° C. for 30 minutes to prepare a mixed solution with a mass fraction of 17.5 wt %, wherein the mass fraction of barium titanate in the mixed solute was 4.76 wt %.

[0069] Using an electrospinning device equipped with a flat-plate collector (see Figure 1 ) for preparation. The above solution is injected into a 15mL syringe with a needle size of 21G. The syringe is fixed on the propeller on one side of the flat fiber receiver. The propulsion speed is set to 1mL / h. The distance between the injection pump nozzle and the surface of the fiber receiver is 10cm. The voltage of the positive pressure spinning system of the high-voltage electric field is +17kV, the power of the negative pressure spinning system is -3kV, the flat fiber collector is 10cm long, 10cm wide and 2mm thick. The preparation environment is 24°C and 35% humidity. The mixed solution is injected into the high-voltage electric field from the energized injection pump nozzle. Polystyrene and thermoplastic polyurethane are deformed under the stable electrostatic force stretching, and the organic solvent evaporates at the same time. Finally, the resin is collected into a film by the energized fiber collector in the form of fiber. After the electrospinning is completed, it needs to be dried in an oven for 6 hours to completely remove the residual solvent, and a double-wetting atmospheric water collection membrane of polystyrene and thermoplastic polyurethane is obtained. The quantitative amount of the obtained double-wetting atmospheric water collection membrane is 20g / m 2 .

[0070] Example 3

[0071] A dual-wetting atmospheric water collection membrane, the preparation steps of the collection membrane are as follows:

[0072] Weigh a certain amount of polystyrene (PS) and thermoplastic polyurethane (TPU) powders, mix them in a mass ratio of 9:1, add dimethylacetamide (DMAC) solvent, stir and dissolve them at 80° C. for 4 hours, and prepare a first solution with a mass fraction of 20 wt %;

[0073] A certain amount of barium titanate (BaTiO3) powder was weighed, and dimethylacetamide (DMAC) solvent was added, and stirred at 60°C for 1 hour to prepare a second solution with a mass fraction of 5wt%.

[0074] The first solution and the second solution were mixed in a mass ratio of 5:1, stirred and dissolved at 60° C. for 30 minutes to prepare a mixed solution with a mass fraction of 17.5 wt %, wherein the mass fraction of barium titanate in the mixed solute was 4.76 wt %.

[0075] Using an electrospinning device equipped with a flat-plate collector (see Figure 1) for preparation. The above solution is injected into a 15mL syringe with a needle size of 21G. The syringe is fixed on the propeller on one side of the flat fiber receiver. The propulsion speed is set to 1mL / h. The distance between the injection pump nozzle and the surface of the fiber receiver is 10cm. The voltage of the positive pressure spinning system of the high-voltage electric field is +17kV, the power of the negative pressure spinning system is -3kV, the flat fiber collector is 10cm long, 10cm wide and 2mm thick. The preparation environment is 24°C and 35% humidity. The mixed solution is injected into the high-voltage electric field from the energized injection pump nozzle. Polystyrene and thermoplastic polyurethane are deformed under the stable electrostatic force stretching, and the organic solvent evaporates at the same time. Finally, the resin is collected into a film by the energized fiber collector in the form of fiber. After the electrospinning is completed, it needs to be dried in an oven for 6 hours to completely remove the residual solvent, and a double-wetting atmospheric water collection membrane of polystyrene and thermoplastic polyurethane is obtained. The quantitative amount of the obtained double-wetting atmospheric water collection membrane is 20g / m 2 .

[0076] Comparative Example 1

[0077] A dual-wetting atmospheric water collection membrane, the preparation steps of the collection membrane are as follows:

[0078] Weigh a certain amount of polystyrene (PS) and add dimethylacetamide (DMAC) solvent, stir and dissolve at 80° C. for 4 hours to prepare a first solution with a mass fraction of 20 wt %;

[0079] A certain amount of barium titanate (BaTiO3) powder was weighed, and dimethylacetamide (DMAC) solvent was added, and stirred at 60°C for 1 hour to prepare a second solution with a mass fraction of 5wt%.

[0080] The first solution and the second solution were mixed in a mass ratio of 5:1, stirred and dissolved at 60° C. for 30 minutes to prepare a mixed solution with a mass fraction of 17.5 wt %, wherein the mass fraction of barium titanate in the mixed solute was 4.76 wt %.

[0081] Using an electrospinning device equipped with a flat-plate collector (see Figure 1) for preparation. The above solution is injected into a 15mL syringe with a needle size of 21G. The syringe is fixed on the propeller on one side of the flat fiber receiver. The propulsion speed is set to 1mL / h. The distance between the injection pump nozzle and the surface of the fiber receiver is 10cm. The voltage of the positive pressure spinning system of the high-voltage electric field is +17kV, the power of the negative pressure spinning system is -3kV, the flat fiber collector is 10cm long, 10cm wide and 2mm thick. The preparation environment is 24°C and 35% humidity. The mixed solution is injected into the high-voltage electric field from the energized injection pump nozzle. Polystyrene and thermoplastic polyurethane are deformed under the stable electrostatic force stretching, and the organic solvent evaporates at the same time. Finally, the resin is collected into a film by the energized fiber collector in the form of fiber. After the electrospinning is completed, it needs to be dried in an oven for 6 hours to completely remove the residual solvent, and a double-wetting atmospheric water collection membrane of polystyrene and thermoplastic polyurethane is obtained. The quantitative amount of the obtained double-wetting atmospheric water collection membrane is 20g / m 2 .

[0082] Comparative Example 2

[0083] A dual-wetting atmospheric water collection membrane, the preparation steps of the collection membrane are as follows:

[0084] Weigh a certain amount of thermoplastic polyurethane (TPU), add dimethylacetamide (DMAC) solvent, stir and dissolve at 80° C. for 4 hours to prepare a first solution with a mass fraction of 20 wt %;

[0085] A certain amount of barium titanate (BaTiO3) powder was weighed, and dimethylacetamide (DMAC) solvent was added, and stirred at 60°C for 1 hour to prepare a second solution with a mass fraction of 5wt%.

[0086] The first solution and the second solution were mixed in a mass ratio of 5:1, stirred and dissolved at 60° C. for 30 minutes to prepare a mixed solution with a mass fraction of 17.5 wt %, wherein the mass fraction of barium titanate in the mixed solute was 4.76 wt %.

[0087] Using an electrospinning device equipped with a flat-plate collector (see Figure 1) for preparation. The above solution is injected into a 15mL syringe with a needle size of 21G. The syringe is fixed on the propeller on one side of the flat fiber receiver. The propulsion speed is set to 1mL / h. The distance between the injection pump nozzle and the surface of the fiber receiver is 10cm. The voltage of the positive pressure spinning system of the high-voltage electric field is +17kV, the power of the negative pressure spinning system is -3kV, the flat fiber collector is 10cm long, 10cm wide and 2mm thick. The preparation environment is 24°C and 35% humidity. The mixed solution is injected into the high-voltage electric field from the energized injection pump nozzle. Polystyrene and thermoplastic polyurethane are deformed under the stable electrostatic force stretching, and the organic solvent evaporates at the same time. Finally, the resin is collected into a film by the energized fiber collector in the form of fiber. After the electrospinning is completed, it needs to be dried in an oven for 6 hours to completely remove the residual solvent, and a double-wetting atmospheric water collection membrane of polystyrene and thermoplastic polyurethane is obtained. The quantitative amount of the obtained double-wetting atmospheric water collection membrane is 20g / m 2 .

[0088] Performance Testing

[0089] 1. The double wettability atmospheric water collection membranes collected in Examples 1 to 3 were observed using a cold field scanning electron microscope. The observation results of Example 1 are shown in the attached figure. Figure 2 As shown by Figure 2 It can be seen that when the mass ratio of polystyrene (PS) to thermoplastic polyurethane (TPU) is 1:1, the diameter of the fiber obtained by electrospinning is about 500 nm. The observation results of Example 2 are shown in the attached figure. Figure 3 As shown in FIG. 1 , when the mass ratio of polystyrene (PS) to thermoplastic polyurethane (TPU) is 7:3, the diameter of the fiber obtained by electrospinning is about 600 nm. The observation results of Example 3 are shown in FIG. Figure 4 As shown in Figure 1, when the mass ratio of polystyrene (PS) to thermoplastic polyurethane (TPU) is 9:1, the diameter of the fiber obtained by electrospinning is about 900 nm. The change in fiber diameter is because the increase in the content of polystyrene with a higher molecular weight makes the fiber diameter thicker.

[0090] 2. Use a contact angle meter to test the water contact angle of Examples 1-3. The specific process is as follows: inject distilled water into a 1 mL syringe, randomly select 5 positions on the sample surface for titration, set the titration amount to 5 μL / drop, measure the contact angle between the water droplets and the sample surface, and take the average as the water contact angle of the sample.

[0091] The embodiments and comparative examples were Figure 5The self-built water collection platform shown in the figure tests the water collection capacity of the fiber. The specific process is: use a fixed-power sprayer to continuously spray water mist at the same flow rate onto the surface of the suspended electrospun membrane sample for 1 hour, with the spray outlet 10 cm away from the sample surface. Place an open beaker directly below the sample to collect the water dripping from the sample surface. After the test, weigh the amount of water collected in the beaker and record it. The water collection capacity of the sample is expressed in milligrams of water collected per square centimeter of membrane per hour (mg / cm 2 / h) as the unit of measurement. Five samples of each example and comparative example were taken for testing, and the average was taken as the water collection capacity of the sample.

[0092] The test results are shown in Table 1.

[0093] Table 1 Test results of water contact angle and water collection capacity

[0094]

[0095] It can be seen from Table 1 that the water contact angle test results of Examples 1-3 and Comparative Examples 1-2 show that as the mass proportion of the hydrophobic material polystyrene (PS) in the dual-wettability atmospheric water collection membrane made of a mixture of polystyrene (PS) and thermoplastic polyurethane (TPU) increases, the water contact angle of the membrane increases. This is because the area of ​​the hydrophobic part of the fiber surface increases with the increase in PS, which affects the wetting properties of its surface. It also further shows that the fiber surface of this dual-wettability collection membrane has both hydrophilic and hydrophobic parts, and its surface has dual wettability.

[0096] It can be seen from Table 1 that the water collection capacity test results of Examples 1-3 and Comparative Examples 1-2 show that the water collection capacity values ​​of Examples 1-3 are all higher than those of Comparative Examples 1-2, indicating that the water collection capacity of the double wettability collection membrane is higher than that of the single wettability collection membrane. This is because the combination of hydrophilic and hydrophobic materials improves the efficiency of the double wettability collection membrane in absorbing water and then draining water, thereby improving the water collection capacity. The water collection capacity values ​​of Examples 1 and 3 are both lower than those of Example 2. The results show that as the mass proportion of the hydrophobic material polystyrene (PS) in the double wettability atmospheric water collection membrane increases, the water collection capacity of the collection membrane first increases and then decreases. This shows that the ratio of the hydrophobic part and the hydrophilic part in the double wettability membrane will affect the water collection capacity of the membrane. Adjusting the ratio of hydrophilic and hydrophobic materials can effectively adjust the water collection capacity of the double wettability collection membrane to meet different water collection needs.

[0097] The above are only preferred embodiments of the present invention, and do not limit the patent scope of the present invention. For those skilled in the art, the present invention may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the patent protection scope of the present invention.

Claims

1. A dual-wetting atmospheric water collection membrane, characterized in that: The material of the dual wettability atmospheric water collection membrane includes a hydrophobic material and a hydrophilic material.

2. The double wettability atmospheric water collection membrane according to claim 1, characterized in that: The mass proportion of the hydrophobic material in the material of the dual wettability atmospheric water collection membrane is (50-90)%.

3. The double wettability atmospheric water collection membrane according to claim 1, characterized in that: The hydrophobic material is polystyrene, and the number average molecular weight of the polystyrene is 15w-20w.

4. The double wettability atmospheric water collection membrane according to claim 1, characterized in that: The hydrophilic material is thermoplastic polyurethane.

5. The double wettability atmospheric water collection membrane according to claim 1, characterized in that: The dual wettability atmospheric water collection membrane further comprises a filler, and the filler comprises a conductive medium.

6. A method for preparing a dual-wetting atmospheric water collection membrane as claimed in any one of claims 1 to 5, characterized in that: The method comprises the following preparation steps: S10, dissolving and mixing the hydrophobic material and the hydrophilic material to obtain a mixed solution; S20, electrostatically spinning the mixed solution, collecting it into a membrane, and drying it to obtain a dual-wetting atmospheric water collection membrane.

7. The method for preparing a dual-wetting atmospheric water collection membrane according to claim 6, characterized in that: Step S10 includes: S101, mixing a hydrophobic material and a hydrophilic material with a solvent to obtain a first solution; S102, mixing the conductive medium with a solvent to obtain a second solution; S103, mixing the first solution and the second solution to obtain a mixed solution.

8. The method for preparing a dual-wetting atmospheric water collection membrane according to claim 7, characterized in that: In step S101, the solvent includes dimethylacetamide.

9. The method for preparing a dual-wetting atmospheric water collection membrane according to claim 7, characterized in that: In step S102, the conductive medium includes barium titanate.

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