A self-driven super high water-permeable material and its preparation method

Abstract

The present invention discloses a self-driven super water-conducting material and a preparation method thereof, belonging to the field of fluid transmission. The preparation method includes the following steps: (1) Preparation of a porous cellulose membrane: Mix a spinning polymer and a solvent evenly to obtain a spinning solution; then prepare a porous cellulose membrane by electrospinning the spinning solution; obtain porous cellulose membranes with different fiber diameters by changing the concentration of the spinning solution; add a black photothermal conversion material to the spinning solution to obtain a porous cellulose membrane loaded with a photothermal conversion material; (2) Hydrophilic modification: Perform hydrophilic modification on the porous cellulose membrane obtained in step (1) to obtain a highly hydrophilic porous fiber membrane; (3) Preparation of the super water-conducting material: Process the highly hydrophilic porous fiber membrane in step (2) into fiber bundles, and then longitudinally assemble and encapsulate to obtain the self-driven super water-conducting material.

Description

Technical Field

[0001] The present invention belongs to the field of fluid transmission, and particularly relates to a self-driven super water-conducting material and a preparation method thereof. Background Art

[0002] A self-driven super water-conducting material is a material that can promote the spontaneous movement of water and significantly increase the water level without external energy. The fine control of water transportation and the effective increase in water level by the self-driven super water-conducting material have very important practical values in industry, medicine, and agriculture. At the same time, the characteristic of no external energy input meets the development requirements of energy conservation and emission reduction in the industry. Therefore, the research and development of self-driven super water-conducting materials are of great significance.

[0003] However, the self-driven water-conducting performance of existing water-conducting materials is poor, mainly reflected in two aspects. One is that the self-driven water-conducting height is relatively low. Currently, most self-driven water-conducting materials are hydrophilic textile materials, such as cotton fabrics, viscose fabrics, etc. Their water-conducting heights are only 7-9 cm. For example, Dai Yue et al. from Nantong University used a moisture-absorbing and sweat-releasing agent to pad-roll cotton fabrics, and the water-conducting height of the treated cotton fabrics increased to about 10 cm. Chen et al. from Donghua University prepared a PAN-SiO2 (polyacrylonitrile-silica) ultrafine fiber membrane by electrospinning, and the highest water-conducting height could reach 19.5 cm. However, these water-conducting materials cannot break through the super water-conducting height of 40 cm, and their application effects in actual scenarios are limited. On the other hand, in order to achieve a water level increase of more than 40 cm, large mechanical devices (such as pumps, etc.) and continuous energy consumption are often required, but this method does not conform to the current industry development trend of energy conservation and emission reduction. Therefore, the preparation of a water-conducting material with self-driven super water-conducting effect is still a challenge. Summary of the Invention

[0004] [Technical Problem]

[0005] Currently, some of the existing water-conducting materials have too low water-conducting heights, and their application effects are limited; some have very high water-conducting heights, but require a large amount of energy consumption. That is, the existing water-conducting materials cannot achieve a super water-conducting height of more than 40 cm without external energy.

[0006] [Technical Solution]

[0007] To solve the above problems, the present invention first prepares a polymer fiber membrane with high porosity and low pore diameter through electrospinning, and then performs hydrophilic modification to achieve the preparation of a highly hydrophilic porous fiber membrane. After cutting, twisting, etc., it is further processed to form fiber bundles. By changing the concentration of the spinning solution during electrospinning and introducing a black photothermal conversion material, fiber bundles with different pore diameters and fiber bundles loaded with photothermal conversion materials are obtained. After longitudinal assembly in sequence and then encapsulation, a self-driven ultra-high water-conducting material is obtained.

[0008] The first object of the present invention is to provide a method for preparing a self-driven ultra-high water-conducting material, comprising the following steps:

[0009] (1) Preparation of a porous cellulose membrane:

[0010] Mix the spinning polymer and the solvent evenly to obtain a spinning solution; then prepare a porous cellulose membrane from the spinning solution through electrospinning; wherein, change the concentration of the spinning solution to prepare porous cellulose membranes with different fiber diameters; add a black photothermal conversion material to the spinning solution to obtain a black porous cellulose membrane;

[0011] (2) Hydrophilic modification:

[0012] Perform hydrophilic modification on the porous cellulose membranes with different fiber diameters and the black porous cellulose membranes obtained in step (1) to obtain corresponding highly hydrophilic porous fiber membranes with different fiber diameters and black highly hydrophilic porous cellulose membranes;

[0013] (3) Preparation of the ultra-high water-conducting material:

[0014] Process the highly hydrophilic porous fiber membranes with different fiber diameters and the black highly hydrophilic porous cellulose membranes obtained in step (2) into corresponding fiber bundles, and then longitudinally assemble and encapsulate to obtain the described self-driven ultra-high water-conducting material.

[0015] In an embodiment of the present invention, the spinning polymer in step (1) is one or more of cellulose and its derivatives, collagen, chitosan (PA), silk fibroin (SF), polyacrylonitrile (PAN), polyamide (PA), polylactic acid (PLA), polyvinylidene fluoride (PVDF), polycaprolactone (PCL), polyurethane (PU), polystyrene (PS).

[0016] Preferably, the spinning polymer in step (1) is cellulose acetate.

[0017] In one embodiment of the present invention, the solvent in step (1) is one or more of aqueous lithium chloride solution, ethanol, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), acetone, N-methylmorpholine N-oxide (NMMO), water, aqueous sodium hydroxide solution, aqueous thiourea solution, aqueous urea solution, ionic liquid (AMIMCI), formic acid, acetic acid, trifluoroacetic acid (TFA), trifluoroethanol (TFE), chloroform (TCM), dichloromethane (DCM), hexafluoroisopropanol (HFIP), and tetrahydrofuran (THF).

[0018] In one embodiment of the present invention, the concentrations of the aqueous lithium chloride solution, aqueous sodium hydroxide solution, aqueous thiourea solution, and aqueous urea solution are 1-90%.

[0019] Preferably, the solvent in step (1) is N,N-dimethylacetamide and acetone, and the mass ratio is 1:2.

[0020] In one embodiment of the present invention, the mixing in step (1) is uniform by stirring for 1-3 h.

[0021] In one embodiment of the present invention, the mass fraction of the spinning polymer in the solvent in step (1) is 5-30%.

[0022] In one embodiment of the present invention, changing the concentration of the spinning solution in step (1) means that the difference between adjacent concentrations after the change is 1-5%.

[0023] Preferably, the concentrations of the spinning solution in step (1) are 13%, 15%, and 17%.

[0024] In one embodiment of the present invention, the parameters of the electrospinning in step (1) are: the spinning distance is 5-30 cm, the spinning voltage is 5-30 kV, the electrospinning time is 0.5-10 h, the spinning temperature is 10-40 °C, and the spinning humidity is 20-100%.

[0025] Preferably, the parameters of the electrospinning in step (1) are: 25 °C, 80% RH, spinning distance 15 cm, spinning voltage 25 kV, and spinning time 5 h.

[0026] In one embodiment of the present invention, the electrospinning in step (1) uses a special spinning syringe, the specification is 5-50 mL, and the inner diameter range of the needle of the special spinning syringe used is 0.16-3 mm.

[0027] In one embodiment of the present invention, the black photothermal conversion material in step (1) is one or more of carbon black and its derivatives, carbon nanotubes and their derivatives, graphene and its derivatives, and MXene.

[0028] Preferably, the black photothermal conversion material in step (1) is carbon nanotubes.

[0029] In an embodiment of the present invention, the mass fraction of the black photothermal conversion material in the spinning solution in step (1) is 0.1-5%.

[0030] Preferably, the mass fraction of the black photothermal conversion material in the spinning solution in step (1) is 0.4%.

[0031] In an embodiment of the present invention, the fiber diameter of the porous cellulose membrane with different fiber diameters in step (1) is 0.2-5 μm.

[0032] In an embodiment of the present invention, the fiber diameter of the black porous cellulose membrane in step (1) is 0.1-5 μm.

[0033] In an embodiment of the present invention, the hydrophilic modification in step (2) is plasma modification, and the parameters of the plasma modification are a power of 10-160 W and a treatment time of 1-15 min.

[0034] Preferably, the hydrophilic modification in step (2) is plasma treatment at a power of 100 W for 10 min.

[0035] In an embodiment of the present invention, the contact angle of the highly hydrophilic polymer fiber membrane in step (2) is 0-10°.

[0036] In an embodiment of the present invention, the processing in step (3) is by cutting and twisting.

[0037] In an embodiment of the present invention, the twist contraction rate of the fiber bundle in step (3) is 3-40%.

[0038] In an embodiment of the present invention, the pore diameter of the fiber bundle in step (3) is 0.2-50 μm.

[0039] In an embodiment of the present invention, the longitudinal assembly in step (3) is to arrange the fiber bundles with the same fiber diameter in one layer, and then the fiber diameter in the fiber bundles gradually decreases from bottom to top, and the fiber bundle loaded with the photothermal conversion material is placed on the top layer.

[0040] In an embodiment of the present invention, the length of each section of the fiber bundle longitudinally assembled in step (3) is 10-50 cm.

[0041] Preferably, the length of the fiber bundle longitudinally assembled in step (3) is 33 cm.

[0042] In one embodiment of the present invention, the encapsulation in step (3) is performed using a sealed plastic shell.

[0043] In one embodiment of the present invention, the material of the sealed shell used in the encapsulation in step (3) is one or more of polymethyl methacrylate (PMMA), polycarbonate (PC), polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), and glass.

[0044] In one embodiment of the present invention, the space occupancy rate of the fiber bundle in the space after encapsulation in step (3) is 10 - 100%.

[0045] Preferably, the space occupancy rate of the fiber bundle in the encapsulation material in step (3) is 78.5%.

[0046] The second object of the present invention is the self - driven ultra - high water - conducting material prepared by the method described in the present invention.

[0047] The third object of the present invention is the application of the self - driven ultra - high water - conducting material described in the present invention in the fields of microfluidic chips and automatic irrigation.

[0048] [Beneficial Effects]

[0049] Aiming at the problem that the existing water - conducting materials cannot achieve an ultra - high water - conducting height of more than 40 cm without an external energy source, the present invention designs and prepares a self - driven ultra - high water - conducting material. The preparation method of the self - driven ultra - high water - conducting material is simple and has low requirements for the types and properties of the spinning polymer materials. The water - conducting height of the water - conducting material prepared by the method described in the present invention is significantly improved, which is significantly better than the technical effects of most current water - conducting materials. Moreover, it does not require an external energy source, has excellent self - driven water - conducting effects, and saves energy and reduces emissions. In addition, the self - driven ultra - high water - conducting material prepared by the present invention is suitable for water transmission in all directions, especially the water - conducting effect in the difficult vertical direction is significantly better than that of the current water - conducting materials. Description of the Drawings

[0050] Figure 1 It is a (a) schematic diagram and (b) top view of the self - driven ultra - high water - conducting material. Detailed Embodiments

[0051] The following describes the preferred embodiments of the present invention. It should be understood that the embodiments are for better explaining the present invention and are not used to limit the present invention.

[0052] Source of Raw Materials

[0053] Cellulose acetate is from Aladdin Reagent Co., Ltd., N,N - dimethylacetamide (DMAc) and acetone are from Shanghai Macklin Biochemical Technology Co., Ltd., and carbon nanotubes are purchased from Nanjing Xianfeng Nano Co., Ltd.

[0054] Testing method:

[0055] Water conduction height: Place the sample in a natural hanging position with its bottom immersed 1 cm below the water surface. After the wetting reaches equilibrium, record the height difference between the highest position where the water wets the sample and the water level. This is the water conduction height of the sample.

[0056] Space occupancy: Calculate the percentage of the cross-sectional area of the fiber bundle to the cross-sectional area of the encapsulation material under the top view of the water-conducting material ( Figure 1 (b)). The specific calculation method is as shown in Equation 1:

[0057] Space occupancy (%) = [π(side length / 2)^2] / [side length × side length] × 100% Equation (1)

[0058] Example 1

[0059] (1) Respectively mix 2.6 g, 3.0 g, and 3.4 g of cellulose acetate with 20 g of a mixed solution composed of DMAc and acetone (DMAc:acetone = 1:2 w / w). After mixing, stir for 2 h until the cellulose acetate is completely dissolved to form homogeneous and transparent cellulose acetate spinning solutions with mass concentrations of 13%, 15%, and 17%. Let it stand for 0.5 h to defoam, and obtain the cellulose acetate spinning solutions.

[0060] (2) Mix 2.6 g of cellulose acetate with a mixed solution composed of 17.4 g of DMAc and acetone (DMAc:acetone = 1:2 w / w). After mixing, stir for 2 h until the cellulose acetate is completely dissolved to form a homogeneous and transparent cellulose acetate spinning solution with a mass concentration of 13%. Then add 0.052 g of carbon nanotubes, disperse evenly by ultrasonic treatment for 1 h, and let it stand for 0.5 h to defoam, obtaining a black cellulose acetate spinning solution.

[0061] (3) Inject the cellulose acetate spinning solutions prepared in step (1) into 10 mL syringes respectively, place them in an electrospinning device, and perform electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain cellulose acetate membranes. Then, plasma-treat the cellulose acetate membranes at a power of 100 W for 10 min. Cut the plasma-treated cellulose acetate membranes into strips 1 cm wide, and perform twisting treatment under the condition of a twisting shrinkage rate of 20% to form fiber bundles. The fiber diameters of the nanofiber bundles of cellulose acetate with mass concentrations of 13%, 15%, and 17% are 0.480 μm, 0.537 μm, and 1.051 μm respectively, and the pore diameters are 1.316 μm, 1.644 μm, and 2.061 μm respectively.

[0062] (4) Inject the black cellulose acetate spinning solution prepared in step (2) into a 10 mL syringe, place it in an electrospinning device, and perform electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain a black cellulose acetate fiber membrane loaded with carbon nanotubes. Then, plasma-treat the black cellulose acetate fiber membrane loaded with carbon nanotubes at a power of 100 W for 10 min. Cut the plasma-treated black cellulose acetate fiber membrane loaded with carbon nanotubes into strips 1 cm wide, and perform twisting treatment under the condition of a twist contraction rate of 20% to form a fiber bundle loaded with carbon nanotubes. The fiber diameter of the fiber bundle loaded with carbon nanotubes is 0.649 μm, and the pore size is 9.055 μm.

[0063] (5) Arrange the fiber bundles prepared in step (3) longitudinally from bottom to top in the order of decreasing fiber diameter, and assemble the fiber bundle loaded with carbon nanotubes prepared in step (4) at the top. The length of each fiber bundle is 33 cm. Finally, encapsulate the fiber bundles in the manner of Figure 1 using PMMA to obtain a self-driven ultra-high water-permeable material. The space occupancy rate of the fiber bundles in the encapsulating material is 78.5%.

[0064] After testing the water conduction height, it is found that the maximum water conduction height of Example 1 is 107 cm, showing an ultra-high water conduction effect.

[0065] Example 2

[0066] Example 2 changed the twist contraction rate in Example 1.

[0067] (1) Respectively mix 2.6 g, 3.0 g, and 3.4 g of cellulose acetate with a 20 g mixed solution composed of DMAc and acetone (DMAc:acetone = 1:2 w / w), stir for 2 h after mixing to completely dissolve the cellulose acetate, form uniform and transparent cellulose acetate spinning solutions with mass concentrations of 13%, 15%, and 17%, let stand for 0.5 h to defoam, and obtain cellulose acetate spinning solutions.

[0068] (2) Mix 2.6 g of cellulose acetate with a mixed solution composed of 17.4 g of DMAc and acetone (DMAc:acetone = 1:2 w / w), stir for 2 h after mixing to completely dissolve the cellulose acetate, form a uniform and transparent cellulose acetate spinning solution with a mass concentration of 13%, add 0.052 g of carbon nanotubes thereto, disperse evenly by ultrasonic treatment for 1 h, let stand for 0.5 h to defoam, and obtain a black cellulose acetate spinning solution.

[0069] (3) Inject the cellulose acetate spinning solution prepared in step (1) into a 10 mL syringe, place it in an electrospinning device, and perform electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain a cellulose acetate membrane. Then, subject the cellulose acetate membrane to plasma treatment at a power of 100 W for 10 min. Cut the plasma-treated cellulose acetate membrane into strips 1 cm wide and perform twisting treatment under the condition of a twist contraction rate of 5% to form fiber bundles. The diameters of the nanofiber bundles of cellulose acetate with mass concentrations of 13%, 15%, and 17% are 0.480 μm, 0.537 μm, and 1.051 μm, and the pore sizes are 1.523 μm, 1.862 μm, and 2.852 μm.

[0070] (4) Inject the black cellulose acetate spinning solution prepared in step (2) into a 10 mL syringe, place it in an electrospinning device, and perform electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain a black cellulose acetate membrane loaded with carbon nanotubes. Then, subject the black cellulose acetate membrane loaded with carbon nanotubes to plasma treatment at a power of 100 W for 10 min. Cut the plasma-treated black cellulose acetate membrane loaded with carbon nanotubes into strips 1 cm wide and perform twisting treatment under the condition of a twist contraction rate of 5% to form a fiber bundle loaded with carbon nanotubes. The fiber diameter of the nanofiber bundle of the fiber bundle loaded with carbon nanotubes is 0.649 μm, and the pore size is 9.055 μm.

[0071] (5) Arrange the fiber bundles prepared in step (3) longitudinally from bottom to top in descending order of fiber diameter, and assemble the fiber bundle loaded with carbon nanotubes prepared in step (4) at the top. The length of each fiber bundle is 33 cm. Finally, encapsulate the fiber bundles with PMMA in the manner of Figure 1 to obtain a self-driven super-high water-conducting material. The space occupancy rate of the fiber bundles in the encapsulating material is 78.5%.

[0072] After testing the water-conducting height, it is found that the maximum water-conducting height of Example 2 is 106 cm, showing a super-high water-conducting effect.

[0073] Example 3

[0074] Example 3 changes the space occupancy rate after encapsulation in Example 1.

[0075] (1) Respectively, 2.6 g, 3.0 g, and 3.4 g of cellulose acetate were mixed with 20 g of a mixed solution composed of DMAc and acetone (DMAc:acetone = 1:2 w / w). After mixing, it was stirred for 2 h to completely dissolve the cellulose acetate, forming uniform and transparent cellulose acetate spinning solutions with mass concentrations of 13%, 15%, and 17%. It was left standing for 0.5 h to defoam, and the cellulose acetate spinning solutions were obtained.

[0076] (2) A mixed solution composed of 2.6 g of cellulose acetate and 17.4 g of DMAc and acetone (DMAc:acetone = 1:2 w / w) was mixed and stirred for 2 h to completely dissolve the cellulose acetate, forming a uniform and transparent cellulose acetate spinning solution with a mass concentration of 13%. Then, 0.052 g of carbon nanotubes was added thereto, and it was ultrasonicated for 1 h to disperse evenly. It was left standing for 0.5 h to defoam, and a black cellulose acetate spinning solution was obtained.

[0077] (3) The cellulose acetate spinning solution prepared in step (1) was injected into a 10 mL syringe and placed in an electrospinning device to perform electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain a cellulose acetate membrane. Then, the cellulose acetate membrane was treated by plasma at a power of 100 W for 10 min. The plasma-treated cellulose acetate membrane was cut into strips 1 cm wide and subjected to a twisting treatment under the condition of a twist contraction rate of 20% to form a fiber bundle. The diameters of the nanofiber bundles of cellulose acetate with mass concentrations of 13%, 15%, and 17% were 0.480 μm, 0.537 μm, and 1.051 μm, and the pore sizes were 1.316 μm, 1.644 μm, and 2.061 μm.

[0078] (4) The black cellulose acetate spinning solution prepared in step (2) was injected into a 10 mL syringe and placed in an electrospinning device to perform electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain a black cellulose acetate membrane loaded with carbon nanotubes. Then, the black cellulose acetate membrane loaded with carbon nanotubes was treated by plasma at a power of 100 W for 10 min. The plasma-treated black cellulose acetate membrane loaded with carbon nanotubes was cut into strips 1 cm wide and subjected to a twisting treatment under the condition of a twist contraction rate of 20% to form a fiber bundle loaded with carbon nanotubes. The fiber diameter of the nanofiber bundle of the fiber bundle loaded with carbon nanotubes was 0.649 μm, and the pore size was 9.055 μm.

[0079] (5) The fiber bundles prepared in step (3) were longitudinally arranged from bottom to top in the order of decreasing fiber diameter, and the fiber bundle loaded with carbon nanotubes prepared in step (4) was assembled at the top. The length of each fiber bundle was 33 cm. Finally, the fiber bundles were arranged according to Figure 1The method in [reference] uses PMMA for encapsulation to obtain a self-driven super-high water-conducting material, and the space occupancy rate of the fiber bundle in the encapsulation material is 12.5%.

[0080] After the water-conducting height test, it is obtained that the maximum water-conducting height of Example 3 is 81 cm, showing a super-high water-conducting effect.

[0081] Example 4

[0082] Example 4 changed the longitudinal assembly operation of Example 1.

[0083] 3.4 g of cellulose acetate was mixed with 16.6 g of a mixed solvent composed of DMAc and acetone (DMAc:acetone = 1:2 w / w) and stirred for 2 h to completely dissolve the cellulose acetate, forming a uniform and transparent cellulose acetate spinning solution with a mass concentration of 17%. It was left standing for 0.5 h to defoam. The defoamed spinning solution was injected into a 10 mL syringe and placed in an electrospinning device for electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain a cellulose acetate membrane. Then, the cellulose acetate membrane was treated with plasma at a power of 100 W for 10 min. The plasma-treated cellulose acetate membrane was cut into strips 1 cm wide and subjected to a twisting treatment under a twist contraction rate of 20% to form a fiber bundle. Subsequently, the fiber bundle was Figure 1 encapsulated with PMMA in the manner in [reference] to obtain a water-conducting material. The space occupancy rate of the fiber bundle in the encapsulation material is 78.5%.

[0084] After the water-conducting height test, it is obtained that the maximum water-conducting height of Example 4 is 80.5 cm, showing a good water-conducting effect.

[0085] Example 5

[0086] Example 5 changed the selection of the black photothermal conversion material in Example 1.

[0087] (1) 2.6 g, 3.0 g, and 3.4 g of cellulose acetate were respectively mixed with 20 g of a mixed solution composed of DMAc and acetone (DMAc:acetone = 1:2 w / w), stirred for 2 h to completely dissolve the cellulose acetate, forming uniform and transparent cellulose acetate spinning solutions with mass concentrations of 13%, 15%, and 17%. It was left standing for 0.5 h to defoam to prepare cellulose acetate spinning solutions.

[0088] (2) Mix 2.6 g of cellulose acetate with a mixed solution composed of 17.4 g of DMAc and acetone (DMAc:acetone = 1:2 w / w). After mixing, stir for 2 h to completely dissolve the cellulose acetate, forming a uniform and transparent cellulose acetate spinning solution with a mass concentration of 13%. Then add 0.052 g of carbon black, disperse evenly by ultrasonic treatment for 1 h, and let it stand for 0.5 h to defoam, obtaining a black cellulose acetate spinning solution.

[0089] (3) Inject the cellulose acetate spinning solution prepared in step (1) into 10 mL syringes respectively, place them in an electrospinning device, and carry out electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain cellulose acetate membranes. Then, treat the cellulose acetate membranes with plasma at a power of 100 W for 10 min. Cut the plasma-treated cellulose acetate membranes into strips 1 cm wide and carry out twisting treatment under the condition of a twist contraction rate of 20% to form fiber bundles.

[0090] (4) Inject the black cellulose acetate spinning solution prepared in step (2) into 10 mL syringes, place them in an electrospinning device, and carry out electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain black cellulose acetate membranes loaded with carbon black. Then, treat the black cellulose acetate membranes loaded with carbon black with plasma at a power of 100 W for 10 min. Cut the plasma-treated black cellulose acetate membranes loaded with carbon black into strips 1 cm wide and carry out twisting treatment under the condition of a twist contraction rate of 20% to form fiber bundles loaded with carbon black.

[0091] (5) Arrange the fiber bundles prepared in step (3) longitudinally from bottom to top in the order of decreasing fiber diameter, and assemble the fiber bundles loaded with carbon black prepared in step (4) at the top. The length of each fiber bundle is 33 cm. Finally, encapsulate the fiber bundles with PMMA in the Figure 1 way to obtain a self-driven super high water-conducting material. The space occupancy rate of the fiber bundles in the encapsulating material is 78.5%.

[0092] Example 6

[0093] Example 6 changed the parameters of the plasma treatment in Example 1.

[0094] (1) Respectively mix 2.6 g, 3.0 g, and 3.4 g of cellulose acetate with 20 g of a mixed solution composed of DMAc and acetone (DMAc:acetone = 1:2 w / w). After mixing, stir for 2 h to completely dissolve the cellulose acetate, forming uniform and transparent cellulose acetate spinning solutions with mass concentrations of 13%, 15%, and 17%. Let it stand for 0.5 h to defoam, obtaining cellulose acetate spinning solutions.

[0095] (2) Mix 2.6 g of cellulose acetate with a mixed solution composed of 17.4 g of DMAc and acetone (DMAc:acetone = 1:2 w / w), stir for 2 h after mixing until the cellulose acetate is completely dissolved, form a uniform and transparent cellulose acetate spinning solution with a mass concentration of 13%, add 0.052 g of carbon nanotubes thereto, disperse evenly by ultrasonic treatment for 1 h, and let stand for 0.5 h to defoam, thus obtaining a black cellulose acetate spinning solution.

[0096] (3) Inject the cellulose acetate spinning solution prepared in step (1) into a 10 mL syringe respectively, place it in an electrospinning device, and perform electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain a cellulose acetate membrane. Then, perform plasma treatment on the cellulose acetate membrane at a power of 120 W for 15 min. Cut the plasma-treated cellulose acetate membrane into strips with a width of 1 cm, and perform twisting treatment under the condition that the twist contraction rate is 20% to form a fiber bundle.

[0097] (4) Inject the black cellulose acetate spinning solution prepared in step (2) into a 10 mL syringe, place it in an electrospinning device, and perform electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain a black cellulose acetate membrane loaded with carbon nanotubes. Then, perform plasma treatment on the black cellulose acetate membrane loaded with carbon nanotubes at a power of 100 W for 10 min. Cut the plasma-treated black cellulose acetate membrane loaded with carbon nanotubes into strips with a width of 1 cm, and perform twisting treatment under the condition that the twist contraction rate is 20% to form a fiber bundle loaded with carbon nanotubes.

[0098] (5) Arrange the fiber bundles prepared in step (3) longitudinally from bottom to top in the order of decreasing fiber diameter, and assemble the fiber bundle loaded with carbon nanotubes prepared in step (4) at the top. The length of each fiber bundle is 33 cm. Finally, encapsulate the fiber bundles in the manner of Figure 1 using PMMA to obtain a self-driven super high water-permeable material, and the space occupancy rate of the fiber bundles in the encapsulating material is 78.5%.

[0099] Example 7

[0100] Example 7 changed the spinning solution concentration in Example 1.

[0101] (1) Respectively, 2.4 g, 3.0 g, and 3.6 g of cellulose acetate were mixed with a 20 g mixed solution composed of DMAc and acetone (DMAc:acetone = 1:2 w / w). After mixing, it was stirred for 2 h to completely dissolve the cellulose acetate, forming uniform and transparent cellulose acetate spinning solutions with mass concentrations of 12%, 15%, and 18%. It was left standing for 0.5 h to defoam, and the cellulose acetate spinning solutions were obtained.

[0102] (2) A mixed solution composed of 2.4 g of cellulose acetate and 17.6 g of DMAc and acetone (DMAc:acetone = 1:2 w / w) was mixed and stirred for 2 h to completely dissolve the cellulose acetate, forming a uniform and transparent cellulose acetate spinning solution with a mass concentration of 12%. Then, 0.052 g of carbon nanotubes was added thereto, and it was ultrasonicated for 1 h to disperse evenly. It was left standing for 0.5 h to defoam, and a black cellulose acetate spinning solution was obtained.

[0103] (3) The cellulose acetate spinning solutions prepared in step (1) were respectively injected into 10 mL syringes, placed in an electrospinning device, and electrospun at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain cellulose acetate membranes. Then, the cellulose acetate membranes were treated by plasma at a power of 120 W for 15 min. The plasma-treated cellulose acetate membranes were cut into strips 1 cm wide and were subjected to a twisting treatment under the condition of a twist contraction rate of 20% to form fiber bundles.

[0104] (4) The black cellulose acetate spinning solution prepared in step (2) was injected into a 10 mL syringe, placed in an electrospinning device, and electrospun at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain a black cellulose acetate membrane loaded with carbon nanotubes. Then, the black cellulose acetate membrane loaded with carbon nanotubes was treated by plasma at a power of 100 W for 10 min. The plasma-treated black cellulose acetate membrane loaded with carbon nanotubes was cut into strips 1 cm wide and was subjected to a twisting treatment under the condition of a twist contraction rate of 20% to form a fiber bundle loaded with carbon nanotubes.

[0105] (5) The fiber bundles prepared in step (3) were longitudinally arranged from bottom to top in the order of decreasing fiber diameter, and the fiber bundle loaded with carbon nanotubes prepared in step (4) was assembled at the top. The length of each fiber bundle was 33 cm. Finally, the fiber bundles were encapsulated with PMMA in the manner of Figure 1 to obtain a self-driven super-high water-conducting material. The space occupancy rate of the fiber bundles in the encapsulating material was 78.5%.

[0106] Example 8

[0107] Example 8 was for the measurement of the contact angle.

[0108] (1) 2.6 g, 3.0 g, and 3.4 g of cellulose acetate were respectively mixed with 20 g of a mixed solution composed of DMAc and acetone (DMAc:acetone = 1:2 w / w) to form homogeneous and transparent cellulose acetate spinning solutions with mass concentrations of 13%, 15%, and 17%. After standing for 0.5 h to defoam, cellulose acetate spinning solutions were obtained.

[0109] (2) A mixed solution composed of 2.6 g of cellulose acetate, 16.6 g of DMAc, and acetone (DMAc:acetone = 1:2 w / w) was stirred for 2 h after mixing to completely dissolve the cellulose acetate, forming a homogeneous and transparent cellulose acetate spinning solution with a mass concentration of 13%. Then, 0.052 g of carbon nanotubes was added thereto, and ultrasonic dispersion was carried out for 1 h to make it uniform. After standing for 0.5 h to defoam, a black cellulose acetate spinning solution was obtained.

[0110] (3) The cellulose acetate spinning solution prepared in step (1) was injected into a 10 mL syringe and placed in an electrospinning device to carry out electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain a cellulose acetate membrane. Then, the cellulose acetate membrane was subjected to plasma treatment at a power of 100 W for 10 min.

[0111] (4) The black cellulose acetate spinning solution prepared in step (2) was injected into a 10 mL syringe and placed in an electrospinning device to carry out electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain a black cellulose acetate membrane loaded with carbon nanotubes. Then, the black cellulose acetate membrane loaded with carbon nanotubes was subjected to plasma treatment at a power of 100 W for 10 min.

[0112] Subsequently, the plasma-treated cellulose acetate membrane was cut and subjected to a contact angle test under a contact angle measuring instrument (JC2000DM, Shanghai Zhongchen Digital Technology Equipment Co., Ltd.). It was found that all the plasma-modified cellulose acetate membranes had a water contact angle of 0°, showing hydrophilic characteristics, while the cellulose acetate membranes without plasma modification had a water contact angle of 130°, showing hydrophobic characteristics.

[0113] Example 9

[0114] Example 9 omitted the addition of carbon nanotubes in Example 1.

[0115] (1) Respectively, 2.6 g, 3.0 g, and 3.4 g of cellulose acetate were mixed with a 20 g mixed solution composed of DMAc and acetone (DMAc:acetone = 1:2 w / w). After mixing, it was stirred for 2 h to completely dissolve the cellulose acetate, forming uniform and transparent cellulose acetate spinning solutions with mass concentrations of 13%, 15%, and 17%. It was left standing for 0.5 h to defoam, and the cellulose acetate spinning solutions were obtained.

[0116] (2) The cellulose acetate spinning solutions prepared in step (1) were respectively injected into 10 mL syringes and placed in an electrospinning device for electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain cellulose acetate membranes. Then, the cellulose acetate membranes were treated with plasma at a power of 100 W for 10 min. The plasma-treated cellulose acetate membranes were cut into strips 1 cm wide and were subjected to a twisting treatment under the condition of a twist contraction rate of 20% to form fiber bundles. The fiber diameters of the nanofiber bundles of cellulose acetate with mass concentrations of 13%, 15%, and 17% were 0.480 μm, 0.537 μm, and 1.051 μm respectively, and the pore diameters were 1.316 μm, 1.644 μm, and 2.061 μm respectively.

[0117] (3) The fiber bundles prepared in step (2) were longitudinally arranged from bottom to top in the order of decreasing fiber diameter. The length of each fiber bundle was 33 cm. Finally, the fiber bundles were encapsulated with PMMA in the manner of Figure 1 to obtain a self-driven super-high water-conducting material. The space occupancy rate of the fiber bundles in the encapsulating material was 78.5%.

[0118] After the water-conducting height test, it was obtained that the maximum water-conducting height of Example 9 was 105 cm, showing a super-high water-conducting effect.

[0119] Comparative Example 1

[0120] Comparative Example 1 was the comparative example of Example 1 and lacked the encapsulation step.

[0121] (1) Respectively, 2.6 g, 3.0 g, and 3.4 g of cellulose acetate were mixed with a 20 g mixed solution composed of DMAc and acetone (DMAc:acetone = 1:2 w / w). After mixing, it was stirred for 2 h to completely dissolve the cellulose acetate, forming uniform and transparent cellulose acetate spinning solutions with mass concentrations of 13%, 15%, and 17%. It was left standing for 0.5 h to defoam, and the cellulose acetate spinning solutions were obtained.

[0122] (2) Mix 2.6 g of cellulose acetate with a mixed solution composed of 17.4 g of DMAc and acetone (DMAc:acetone = 1:2 w / w). After mixing, stir for 2 h until the cellulose acetate is completely dissolved to form a homogeneous and transparent cellulose acetate spinning solution with a mass concentration of 13%. Then add 0.052 g of carbon nanotubes, ultrasonically disperse for 1 h until evenly dispersed, and let stand for 0.5 h to defoam, obtaining a black cellulose acetate spinning solution.

[0123] (3) Inject the cellulose acetate spinning solution prepared in step (1) into a 10 mL syringe, place it in an electrospinning device, and perform electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain a cellulose acetate membrane. Then, subject the cellulose acetate membrane to plasma treatment at a power of 100 W for 10 min. Cut the plasma-treated cellulose acetate membrane into strips 1 cm wide and perform twisting treatment under a twist contraction rate of 20% to form a fiber bundle. The diameters of the nanofiber bundles of cellulose acetate with mass concentrations of 13%, 15%, and 17% are 0.480 μm, 0.537 μm, and 1.051 μm, respectively, and the pore sizes are 1.316 μm, 1.644 μm, and 2.061 μm.

[0124] (4) Inject the black cellulose acetate spinning solution prepared in step (2) into a 10 mL syringe, place it in an electrospinning device, and perform electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain a black cellulose acetate membrane loaded with carbon nanotubes. Then, subject the black cellulose acetate membrane loaded with carbon nanotubes to plasma treatment at a power of 100 W for 10 min. Cut the plasma-treated black cellulose acetate membrane loaded with carbon nanotubes into strips 1 cm wide and perform twisting treatment under a twist contraction rate of 20% to form a fiber bundle loaded with carbon nanotubes. The fiber diameter of the nanofiber bundle of the fiber bundle loaded with carbon nanotubes is 0.649 μm, and the pore size is 9.055 μm.

[0125] (5) Arrange the fiber bundles prepared in step (3) longitudinally from bottom to top in the order of decreasing fiber diameter, and assemble the fiber bundle loaded with carbon nanotubes prepared in step (4) at the top. The length of each fiber bundle is 33 cm.

[0126] After the water conduction height test, it is obtained that the maximum water conduction height of Comparative Example 1 is 24.5 m, showing a poor water conduction effect.

[0127] Comparative Example 2

[0128] Comparative Example 2 is a comparison with Example 1, lacking the steps of twisting, hydrophilic modification, encapsulation, and longitudinal assembly.

[0129] 3.4 g of cellulose acetate was mixed with 16.6 g of a mixed solvent composed of DMAc and acetone (DMAc:acetone = 1:2 w / w), and stirred for 2 h to completely dissolve the cellulose acetate, forming a uniform and transparent cellulose acetate spinning solution with a mass concentration of 17%. It was left standing for 0.5 h to remove bubbles. The defoamed spinning solution was injected into a 10 mL syringe and placed in an electrospinning device for electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain a cellulose acetate membrane. Then, the fiber membrane was cut into strips 1 cm wide to obtain a water-conducting material.

[0130] After the water-conducting height test, it was found that the maximum water-conducting height of Comparative Example 2 was 7.5 cm, showing a very poor water-conducting effect.

[0131] Comparative Example 3

[0132] Comparative Example 3 was a comparison with Comparative Example 1, using an alkali solution to replace the plasma treatment for the hydrophilic modification step.

[0133] (1) 2.6 g, 3.0 g, and 3.4 g of cellulose acetate were respectively mixed with 20 g of a mixed solution composed of DMAc and acetone (DMAc:acetone = 1:2 w / w), and stirred for 2 h to completely dissolve the cellulose acetate, forming uniform and transparent cellulose acetate spinning solutions with mass concentrations of 13%, 15%, and 17%. It was left standing for 0.5 h to remove bubbles, and cellulose acetate spinning solutions were prepared.

[0134] (2) A mixed solution composed of 2.6 g of cellulose acetate and 17.4 g of DMAc and acetone (DMAc:acetone = 1:2 w / w) was mixed and stirred for 2 h to completely dissolve the cellulose acetate, forming a uniform and transparent cellulose acetate spinning solution with a mass concentration of 13%. 0.052 g of carbon nanotubes was added thereto, and ultrasonic dispersion was carried out for 1 h to make it uniform. It was left standing for 0.5 h to remove bubbles, and a black cellulose acetate spinning solution was prepared.

[0135] (3) The cellulose acetate spinning solution prepared in step (1) was injected into a 10 mL syringe and placed in an electrospinning device for electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain a cellulose acetate membrane. The cellulose acetate membrane was immersed in 1 L of a 0.5 mol / L sodium hydroxide aqueous solution and left standing for 24 h to obtain a deacetylated cellulose acetate membrane, that is, a hydrophilic alkali cellulose membrane. The hydrophilic alkali cellulose membrane was cut into strips 1 cm wide and subjected to a twisting treatment under the condition of a twist contraction rate of 20% to form fiber bundles. The diameters of the nanofiber bundles with mass concentrations of 13%, 15%, and 17% of cellulose acetate were 0.480 μm, 0.537 μm, and 1.051 μm, and the pore diameters were 1.316 μm, 1.644 μm, and 2.061 μm.

[0136] (4) Inject the black cellulose acetate spinning solution prepared in step (2) into a 10 mL syringe, place it in an electrospinning device, and perform electrospinning at room temperature, 80% RH, a spinning distance of 15 cm, a spinning voltage of 25 kV, and a spinning time of 5 h to obtain a black cellulose acetate membrane loaded with carbon nanotubes. Then, immerse the black cellulose acetate membrane loaded with carbon nanotubes in 1 L of a sodium hydroxide aqueous solution with a concentration of 0.5 mol / L and let it stand for 24 h to obtain a deacetylated cellulose acetate membrane loaded with carbon nanotubes, that is, a hydrophilic carbon nanotube-loaded alkali cellulose membrane. Cut the hydrophilic carbon nanotube-loaded alkali cellulose membrane into strips 1 cm wide and perform a twisting treatment under the condition of a twist contraction rate of 20% to form a fiber bundle loaded with carbon nanotubes.

[0137] (5) Arrange the fiber bundles prepared in step (3) longitudinally from bottom to top in the order of decreasing fiber diameter, and assemble the fiber bundle loaded with carbon nanotubes prepared in step (4) at the top. The length of each fiber bundle is 33 cm. Finally, encapsulate the fiber bundles in the manner of Figure 1 using PMMA to obtain a self-driven ultra-high water-conducting material, and the space occupancy rate of the fiber bundles in the encapsulating material is 78.5%.

[0138] After the water-conducting height test, it is obtained that the maximum water-conducting height of Comparative Example 3 is 5.5 cm, showing a very poor water-conducting effect.

[0139] Comparative Example 4

[0140] Comparative Example 4 is a fiber membrane prepared according to the preparation scheme in the reference document "Biomimetic Aligned Micro- / Nanofibrous Composite Membranes with Ultrafast Water Transport and Evaporation for Efficient Indoor Humidification", and then adding a comparative example of plasma modification and encapsulation.

[0141] 2.8 g of polyacrylonitrile (PAN) powder was mixed with 17.2 g of DMF solvent and stirred for 2 h to completely dissolve PAN, forming a uniform and transparent PAN spinning solution with a mass concentration of 14%. It was left standing for 0.5 h to defoam. The defoamed spinning solution was injected into a 10 mL syringe and placed in an electrospinning device for electrospinning at room temperature, 40% RH, a spinning distance of 15 cm, a spinning voltage of 15 kV, and a spinning time of 5 h to obtain a PAN fiber membrane. Then, the fiber membrane was treated with plasma at a power of 100 W for 10 min. The plasma-treated acetate fiber membrane was cut into strips 1 cm wide and subjected to a twisting treatment under the condition of a twisting shrinkage rate of 20% to form fiber bundles. Subsequently, these fiber bundles were encapsulated with PMMA in the manner of Figure 1 to obtain a water-conducting material. The space occupancy rate of the fiber bundles in the encapsulating material was 78.5%.

[0142] After the water-conducting height test, it was found that the maximum water-conducting height of Comparative Example 4 was 65 cm, showing a better improvement compared to the water-conducting effect in the comparative literature (about 20 cm), but still lower than the water-conducting effect in Example 1.

[0143] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with this technology can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be defined by the claims.

Claims

1. A method for preparing a self-driven super high water-permeable material, characterized in that, It includes the following steps: (1) Preparation of the porous cellulose membrane: Mix the spinning polymer and the solvent evenly to obtain a spinning solution; then prepare the porous cellulose membrane by electrospinning the spinning solution; wherein, change the concentration of the spinning solution to obtain porous cellulose membranes with different fiber diameters; add a black photothermal conversion material to the spinning solution to obtain a black porous cellulose membrane; (2) Hydrophilic modification: Perform hydrophilic modification on the porous cellulose membranes with different fiber diameters and the black porous cellulose membrane obtained in step (1) to obtain highly hydrophilic porous fiber membranes with different fiber diameters and black highly hydrophilic porous cellulose membranes respectively; (3) Preparation of the ultra-high water-conducting material: Process the highly hydrophilic porous fiber membranes with different fiber diameters and the black highly hydrophilic porous cellulose membrane in step (2) into corresponding fiber bundles, and then longitudinally assemble and encapsulate them to obtain the self-driven ultra-high water-conducting material; the twist contraction rate of the fiber bundles is 3-40%, the pore diameter of the fiber bundles is 0.2-50 μm, and the length of each fiber bundle is 10-40 cm; the longitudinal assembly is to arrange the fiber bundles with the same fiber diameter in one layer, and then the fiber diameter in the fiber bundles gradually decreases from bottom to top, and the black fiber bundle is placed on the top layer; the encapsulation is to encapsulate with a sealed plastic shell; the space occupancy rate of the fiber bundles in the encapsulation material is 78.5%.

2. The preparation method according to claim 1, wherein The spinning polymer described in step (1) is one or more of cellulose, collagen, chitosan, silk fibroin, polyacrylonitrile, polyamide, polylactic acid, polyvinylidene fluoride, polycaprolactone, polyurethane, polystyrene.

3. The preparation method according to claim 1, wherein The solvent described in step (1) is one or more of lithium chloride aqueous solution, ethanol, N,N-dimethylformamide, N,N-dimethylacetamide, acetone, N-methylmorpholine oxide, water, sodium hydroxide aqueous solution, thiourea aqueous solution, urea aqueous solution, ionic liquid, formic acid, acetic acid, trifluoroacetic acid, trifluoroethanol, chloroform, dichloromethane, hexafluoroisopropanol, tetrahydrofuran.

4. The preparation method according to claim 1, wherein The mass fraction of the spinning polymer in the solvent in step (1) is 5-30%.

5. The preparation method according to claim 1, characterized in that, The black photothermal conversion material described in step (1) is one or more of carbon black and its derivatives, carbon nanotubes and their derivatives, graphene and its derivatives, MXene.

6. According to the preparation method described in claim 1, characterized in that, The mass fraction of the black photothermal conversion material in the spinning solution in step (1) is 0.1-5%.

7. The preparation method according to claim 1, characterized in that, The fiber diameter of the porous cellulose membrane with different fiber diameters in step (1) is 0.2-5 μm.

8. The preparation method according to claim 1, characterized in that, The fiber diameter of the black porous cellulose membrane in step (1) is 0.1-5 μm.

9. According to the preparation method described in claim 1, characterized in that, The hydrophilic modification described in step (2) is plasma modification.

10. The preparation method according to claim 9, characterized in that, The parameters of the plasma modification are power 10-160 W and treatment time 1-15 min.

11. According to the preparation method described in claim 1, characterized in that, The material of the sealed plastic shell is one or more of polymethacrylate, polycarbonate, polypropylene, polyethylene, polyvinyl chloride, glass.

12. A self-driven ultra-high water-conducting material prepared by the method according to any one of claims 1 to 11.

13. Application of the self-driven ultra-high water-conducting material according to claim 12 in the fields of microfluidic chips and automatic irrigation.

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