Hydrophobic coating, hydrophobic filler, method for producing the same, and use of the hydrophobic filler

Abstract

This invention relates to the field of carbon dioxide capture technology, specifically to a hydrophobic coating, a hydrophobic filler, a method for preparing the same, and the application of the hydrophobic filler. The hydrophobic coating comprises: 1 part by weight of an adhesive, 0.08-0.25 parts by weight of a curing agent, 0.1-0.5 parts by weight of an alkali-modified vinylidene fluoride copolymer, 0.001-0.15 parts by weight of a fluorinated inorganic filler, and 2-8 parts by weight of a coating solvent. The hydrophobic coating provided by this invention, through the combined action of the adhesive, curing agent, alkali-modified vinylidene fluoride copolymer, and fluorinated inorganic filler, not only significantly improves the hydrophobic properties of the coating formed by the hydrophobic coating, but also substantially improves the adsorption properties, wear resistance, corrosion resistance, and thermal stability of the coating formed by the hydrophobic coating.

Description

Technical Field

[0001] This invention relates to the field of carbon dioxide capture technology, specifically to a hydrophobic coating, a hydrophobic filler, a method for preparing the same, and the application of the hydrophobic filler. Background Technology

[0002] After absorbing carbon dioxide, the amine solution generally enters a desorption tower for desorption. That is, in the desorption tower, the absorbent in the absorbent liquid releases the absorbed carbon dioxide, thus completing the regeneration of the absorbent.

[0003] The desorption process of the absorbent is a typical gas-liquid mass transfer process. Desorption towers are generally filled with packing material. Some studies suggest that the hydrophobic surface of the packing material has certain advantages in bubble nucleation and gas-liquid mass transfer, which can improve the desorption effect of the absorbent on CO2. From classical nucleation theory, we know that the nucleation free energy of heterogeneous nucleation is lower than that of homogeneous nucleation. The nucleation free energy of a solid surface is related to the contact angle; surfaces with strong hydrophobicity, i.e., larger contact angles, can generate bubbles more quickly, thus creating more nucleation sites and promoting CO2 desorption.

[0004] CN118558111A discloses a carbon dioxide capture system, which uses a reactor and packing material. The system is filled with a foam packing material, and its preparation method includes: (1) providing metal foam; the average pore size of the metal foam is 50-800 μm; (2) mixing a first catecholamine solution with a buffer solution to obtain a first modified solution; wherein the concentration of catecholamine in the first catecholamine solution is 0.5-5 g / L; (3) mixing the first modified solution and the metal foam in a ratio of 100-500 parts by volume to 1-10 parts by weight. (3) Mix the inorganic nanoparticles, solvent, and fluorinated silane coupling agent in a certain proportion for a first preset time, and then separate the solid and liquid to obtain the first intermediate; (4) Mix the inorganic nanoparticles, solvent, and fluorinated silane coupling agent in a second preset time to obtain the second modified liquid; wherein the concentration of inorganic nanoparticles in the second modified liquid is 1-10 g / L, and the concentration of fluorinated silane coupling agent is 0.2-2 vol%; the maximum particle size of the inorganic nanoparticles is ≤500 nm; (5) Mix the second modified liquid and the first intermediate in a ratio of 100-500 volume parts: 1-10 weight parts for a third preset time to obtain the foam filler. Although the foam filler prepared by this method can improve the hydrophobicity of the foam filler pore surface, enhance the gas-liquid mass transfer performance, increase the liquid flow rate of the water film (i.e., gas-liquid interface) on the foam surface, reduce foam stability, reduce foaming, and shorten the defoaming time, it also has the defects of easy coating peeling, poor wear resistance, insufficient corrosion resistance, and poor thermal stability. Moreover, the hydrophobic performance still needs to be further improved.

[0005] Therefore, there is an urgent need to provide a hydrophobic filler with good hydrophobic properties, coating adsorption properties, wear resistance, corrosion resistance and thermal stability, as well as its preparation method. Summary of the Invention

[0006] The purpose of this invention is to address the problems in the desorption process of amine solutions, such as the need to further improve the hydrophobicity of hydrophobic fillers, and the relatively poor adsorption performance, wear resistance, corrosion resistance, and thermal stability of coatings. This invention provides a hydrophobic coating, a hydrophobic filler, its preparation method, and the application of the hydrophobic filler.

[0007] To achieve the above objectives, a first aspect of the present invention provides a hydrophobic coating comprising: 1 part by weight of an adhesive, 0.08-0.25 parts by weight of a curing agent, 0.1-0.5 parts by weight of an alkali-modified vinylidene fluoride copolymer, 0.001-0.15 parts by weight of a fluorinated inorganic filler, and 2-8 parts by weight of a coating solvent.

[0008] A second aspect of the present invention provides a method for preparing a hydrophobic filler, wherein the method includes spraying the hydrophobic coating described in the first aspect of the present invention onto a filler matrix and then drying it to obtain the hydrophobic filler.

[0009] A third aspect of the present invention provides a hydrophobic filler prepared using the preparation method described in the second aspect of the present invention.

[0010] A fourth aspect of the present invention provides an application of the hydrophobic filler described in the third aspect of the present invention in carbon dioxide capture.

[0011] The beneficial technical effects achieved by the present invention through the above technical solution are as follows: 1) The hydrophobic coating provided by the present invention, with the joint action of adhesive, curing agent, alkali-modified vinylidene fluoride copolymer and fluorinated inorganic filler, can not only significantly improve the hydrophobic properties of the coating formed by the hydrophobic coating, but also greatly improve the adsorption properties, wear resistance, corrosion resistance and thermal stability of the coating formed by the hydrophobic coating. 2) The hydrophobic packing provided by the present invention has a good hydrophobic angle, a large gas-liquid contact area, and good corrosion resistance. It can still maintain hydrophobic properties under the impact of amine solution, which can enhance the mass transfer rate of the packing in the desorption tower, increase the gas-liquid contact area in the desorption tower, and significantly improve the desorption effect of carbon dioxide in the desorption tower. Attached Figure Description

[0012] Figure 1 a is a test diagram of the contact angle of MEA solution on a hydrophobic stainless steel sheet in Test Example 1. Figure 1 b is a test diagram of the contact angle of MEA solution on a blank stainless steel sheet in Test Example 1. Detailed Implementation

[0013] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0014] A first aspect of the present invention provides a hydrophobic coating, wherein the hydrophobic coating comprises: 1 part by weight of an adhesive, 0.08-0.25 parts by weight of a curing agent, 0.1-0.5 parts by weight of an alkali-modified vinylidene fluoride copolymer, 0.001-0.15 parts by weight of a fluorinated inorganic filler, and 2-8 parts by weight of a coating solvent.

[0015] In this invention, the inventors discovered that the combined action of adhesives, curing agents, alkali-modified vinylidene fluoride copolymers, and fluorinated inorganic fillers not only significantly improves the hydrophobic properties of the hydrophobic coating but also substantially enhances the adsorption, wear resistance, corrosion resistance, and thermal stability of the coating formed by the hydrophobic coating. The hydrophobic filler prepared using the hydrophobic coating of this invention can be used in the regeneration tower of carbon dioxide absorbent liquid, significantly increasing the carbon dioxide release rate and extending the service life of the hydrophobic filler.

[0016] In a preferred embodiment of the present invention, the hydrophobic coating comprises: 1 part by weight of adhesive, 0.12-0.18 parts by weight of curing agent, 0.2-0.3 parts by weight of alkali-modified vinylidene fluoride copolymer, 0.08-0.1 parts by weight of fluorinated inorganic filler and 4-6 parts by weight of coating solvent.

[0017] In a preferred embodiment of the present invention, the adhesive is selected from solid resins, preferably from one or more of epoxy resins, polyamide resins, and acrylic resins, and more preferably from epoxy resins.

[0018] In this invention, the fluorinated inorganic filler can be completely wetted by the liquid resin, which easily leads to the covering of the hydrophobic groups and structures of the fluorinated inorganic filler. Furthermore, the large density difference between the fluorinated inorganic filler and the liquid resin causes the fluorinated inorganic filler to easily deposit at the bottom of the coating during film formation, which not only reduces the adhesion and hydrophobic properties of the coating but also leads to phenomena such as pinholes and blooming. Compared to liquid resin, solid resin has better hydrophobicity, and the fluorinated inorganic filler is more uniformly and stably dispersed in solid resin. Therefore, hydrophobic coatings prepared using solid resin have higher film quality, and the coating exhibits better hydrophobicity, adhesion, and film quality.

[0019] In a preferred embodiment of the present invention, the curing agent is selected from one or more of polyamide, m-phenylenediamine, tributyl phosphate, triphenyl phosphate, and diphenyl octyl phosphate, preferably m-phenylenediamine. In this invention, selecting a curing agent containing a benzene ring can further improve the adsorption and corrosion resistance of the hydrophobic coating.

[0020] In a preferred embodiment of the present invention, the method for preparing the alkali-modified vinylidene fluoride copolymer includes: adding the vinylidene fluoride copolymer to an alkaline solution for modification treatment to obtain the alkali-modified vinylidene fluoride copolymer.

[0021] Preferably, the vinylidene fluoride copolymer is a vinylidene fluoride monomer copolymer and / or a copolymer of vinylidene fluoride monomer and tetrafluoroethylene monomer, and more preferably a vinylidene fluoride monomer copolymer.

[0022] In this invention, the vinylidene fluoride monomer copolymer is a polymer formed by the self-polymerization of vinylidene fluoride monomers, and the copolymer of vinylidene fluoride monomers and tetrafluoroethylene monomers is a polymer formed by the polymerization of vinylidene fluoride and tetrafluoroethylene. The inventors of this invention have discovered that hydrophobic coatings prepared using copolymers containing vinylidene fluoride monomers exhibit superior abrasion resistance.

[0023] Preferably, the alkaline solution is selected from one or more of sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, and ammonia aqueous solution, and is preferably sodium hydroxide aqueous solution; the mass concentration of alkali in the alkaline solution is 2-8%, preferably 4-6%.

[0024] Preferably, the mass ratio of the vinylidene fluoride copolymer to the alkaline solution is 1:150-250, more preferably 1g:180-220.

[0025] Preferably, the modification treatment temperature is room temperature, and the modification treatment time is 8-16 hours, preferably 10-14 hours. However, the present invention does not specifically limit the room temperature, which can be 10-35°C.

[0026] In a preferred embodiment of the present invention, the fluorinated inorganic filler is selected from one or more of fluorinated silicon dioxide, fluorinated aluminum hydroxide, fluorinated magnesium hydroxide, fluorinated calcium carbonate, fluorinated kaolin, fluorinated titanium dioxide and fluorinated graphene oxide, preferably fluorinated silicon dioxide.

[0027] In this invention, the surface of the inorganic filler before fluorination generally has a large number of hydroxyl groups, which are highly hydrophilic. Fluorination modification of the inorganic filler helps to further reduce the surface energy of the hydrophobic coating, thereby improving the hydrophobic properties, corrosion resistance and thermal stability of the hydrophobic filler.

[0028] In a preferred embodiment of the present invention, the method for preparing the fluorinated inorganic filler includes: spray drying a suspension containing inorganic filler and PFAS to obtain the fluorinated inorganic filler.

[0029] Preferably, the inorganic filler is selected from one or more of silicon dioxide, aluminum hydroxide, magnesium hydroxide, calcium carbonate, kaolin, titanium dioxide, and graphene oxide, with silicon dioxide being the most preferred. In this invention, inorganic filler sol can also be used.

[0030] Preferably, the PFAS is selected from one or more of perfluorooctyltrichlorosilane (PFTS), 1H,1H,2H,2H-perfluorooctyltriethoxysilane, perfluorooctyltrimethoxysilane, and perfluorooctylethoxysilane, and is more preferably perfluorooctyltrichlorosilane.

[0031] Preferably, the mass ratio of the inorganic filler to PFAS is 1:0.01-0.05, and more preferably 1:0.02-0.03.

[0032] Preferably, the solvent in the suspension is selected from one or more of methanol, ethanol, propanol, butanol, and pentanol, with ethanol being the most preferred. The present invention does not impose a specific limit on the amount of solvent used in the suspension, as long as it ensures uniform dispersion of the inorganic filler and the fluorinated silane.

[0033] Preferably, the spray drying temperature is 100-150℃, and more preferably 110-130℃.

[0034] In a preferred embodiment of the present invention, the coating solvent is selected from one or more of isopropanol, acetone, and petroleum ether, preferably acetone.

[0035] In this invention, acetone is highly volatile. When acetone is used as the solvent for the coating, it can be prepared fresh for immediate use, or the prepared hydrophobic coating can be sealed and stored.

[0036] In a preferred embodiment of the present invention, the preparation method of the hydrophobic coating includes: mixing the adhesive, curing agent, alkali-modified vinylidene fluoride copolymer, fluorinated inorganic filler and coating solvent, and then subjecting the mixture to ultrasonic treatment, preferably ultrasonic treatment for 10-50 minutes, to obtain the hydrophobic coating.

[0037] A second aspect of the present invention provides a method for preparing a hydrophobic filler, wherein the method includes spraying the hydrophobic coating described in the first aspect of the present invention onto a filler matrix and then drying it to obtain the hydrophobic filler.

[0038] In a preferred embodiment of the present invention, the filler matrix is ​​selected from one or more of wire mesh fillers, ring fillers, saddle fillers, and corrugated fillers, preferably wire mesh fillers.

[0039] In this invention, the material of the filler matrix is ​​not specifically limited; it can be metal, plastic, or ceramic. Preferably, the filler matrix is ​​stainless steel wire mesh filler.

[0040] In a preferred embodiment of the present invention, the spraying operation conditions include: the spraying airflow is selected from air, and the spraying flow rate is 10-30 mL / min, preferably 15-25 mL / min.

[0041] In a preferred embodiment of the present invention, the drying is carried out under vacuum, and the drying temperature is 100-150°C, preferably 110-130°C.

[0042] A third aspect of the present invention provides a hydrophobic filler, which is prepared using the preparation method described in the second aspect of the present invention.

[0043] A fourth aspect of the present invention provides an application of the hydrophobic filler described in the third aspect of the present invention in carbon dioxide capture.

[0044] The hydrophobic packing material provided in this invention maintains excellent hydrophobic properties even under the impact of alkanolamine solutions. When used in a desorption tower for carbon dioxide absorption liquid, it enhances the mass transfer rate of the packing material, increases the gas-liquid contact area, and significantly improves the desorption efficiency of carbon dioxide. Furthermore, the coating of the hydrophobic packing material provided in this invention exhibits good adsorption performance, strong wear resistance, high corrosion resistance, and good thermal stability, which can extend the operating cycle of the desorption tower and improve its operational stability.

[0045] The present invention will be described in detail below through embodiments.

[0046] The epoxy resin was bisphenol A type epoxy resin, purchased from the Bailingwei Chemical Reagent website, product number 31185. The polyamide resin was purchased from the Bailingwei Chemical Reagent website, product number PLAS-PL-038N. The acrylic resin was purchased from Runyou Chemical Co., Ltd., Mn2000. The vinylidene fluoride monomer copolymer (i.e., polyvinylidene fluoride resin) was purchased from the Bailingwei Chemical Reagent website, product number 768738. The filler matrix was rolled stainless steel wire mesh filler.

[0047] Preparation of alkali-modified vinylidene fluoride copolymer: The vinylidene fluoride monomer copolymer was mixed with a 5% NaOH aqueous solution at a ratio of 1:200, and stirred continuously at room temperature for 12 hours. Then, the mixture was filtered and dried to obtain the alkali-modified vinylidene fluoride copolymer.

[0048] Preparation of fluorinated inorganic fillers: Based on the silica content in the silica sol, silica sol (silica content of 20wt%) and PFTS (perfluorooctyltrichlorosilane) were added to ethanol at a mass ratio of 1:0.025 and mixed evenly. Then, the mixture was spray-dried at 120°C to obtain fluorinated silica.

[0049] Magnesium hydroxide and perfluorooctylethoxysilane were added to ethanol at a mass ratio of 1:0.01 and mixed thoroughly. The mixture was then spray-dried at 120°C to obtain magnesium hydroxide fluoride.

[0050] Kaolin and perfluorooctylethoxysilane were added to ethanol at a mass ratio of 1:0.04 and mixed evenly. The mixture was then spray-dried at 120°C to obtain fluorinated kaolin.

[0051] Example 1 Epoxy resin, m-phenylenediamine, alkali-modified vinylidene fluoride copolymer, fluorinated silica and acetone were mixed in a mass ratio of 1:0.15:0.25:0.08:5, and then ultrasonically treated for 30 minutes to obtain a hydrophobic coating. Using an air compressor to provide air, the opening of the spray gun nozzle is adjusted to make the spray flow rate of the above hydrophobic coating 20 mL / min, and the above hydrophobic coating is evenly sprayed onto the filler matrix; the filler after spraying is placed in an oven and dried under vacuum at 120°C for 2 hours to obtain the hydrophobic filler.

[0052] Example 2 Epoxy resin, m-phenylenediamine, alkali-modified vinylidene fluoride copolymer, fluorinated silica and acetone were mixed in a mass ratio of 1:0.12:0.2:0.1:6, and then ultrasonically treated for 30 minutes to obtain a hydrophobic coating.

[0053] Using an air compressor to provide air, the opening of the spray gun nozzle is adjusted to make the spray flow rate of the above hydrophobic coating 20 mL / min, and the above hydrophobic coating is evenly sprayed onto the filler matrix; the filler after spraying is placed in an oven and dried under vacuum at 120°C for 2 hours to obtain the hydrophobic filler.

[0054] Example 3 Epoxy resin, m-phenylenediamine, alkali-modified vinylidene fluoride copolymer, fluorinated silica and acetone were mixed in a mass ratio of 1:0.18:0.3:0.09:4, and then ultrasonically treated for 30 minutes to obtain a hydrophobic coating.

[0055] Using an air compressor to provide air, the opening of the spray gun nozzle is adjusted to make the spray flow rate of the above hydrophobic coating 20 mL / min, and the above hydrophobic coating is evenly sprayed onto the filler matrix; the filler after spraying is placed in an oven and dried under vacuum at 120°C for 2 hours to obtain the hydrophobic filler.

[0056] Example 4 Polyamide resin, tributyl phosphate, alkali-modified vinylidene fluoride copolymer, magnesium hydroxide fluoride and isopropanol were mixed in a mass ratio of 1:0.2:0.1:0.04:2, and then ultrasonically treated for 30 minutes to obtain a hydrophobic coating.

[0057] Using an air compressor to provide air, the opening of the spray gun nozzle is adjusted to make the spray flow rate of the above hydrophobic coating 20 mL / min, and the above hydrophobic coating is evenly sprayed onto the filler matrix; the filler after spraying is placed in an oven and dried under vacuum at 120°C for 2 hours to obtain the hydrophobic filler.

[0058] Example 5 Acrylic resin, tributyl phosphate, alkali-modified vinylidene fluoride copolymer, fluorinated kaolin and petroleum ether were mixed in a mass ratio of 1:0.08:0.4:0.15:8, and then ultrasonically treated for 30 minutes to obtain a hydrophobic coating.

[0059] Using an air compressor to provide air, the opening of the spray gun nozzle is adjusted to make the spray flow rate of the above hydrophobic coating 20 mL / min, and the above hydrophobic coating is evenly sprayed onto the filler matrix; the filler after spraying is placed in an oven and dried under vacuum at 120°C for 2 hours to obtain the hydrophobic filler.

[0060] Comparative Example 1 Similar to Example 5, except that the alkali-modified vinylidene fluoride copolymer is replaced by an equal mass of vinylidene fluoride monomer copolymer.

[0061] Comparative Example 2 Similar to Example 5, except that the mass of fluorinated silicon dioxide is replaced with silicon dioxide.

[0062] Test Example 1 The contact angles of the hydrophobic coatings prepared in Examples 1-5 and Comparative Examples 1-2 were tested, and the results are shown in Table 1. The testing method for the contact angles of the hydrophobic coatings is as follows: The hydrophobic coatings prepared in Examples 1-5 and Comparative Examples 1-2 were sprayed onto the surface of 304L stainless steel sheets to obtain hydrophobic stainless steel sheets. Then, a MEA solution with carbon dioxide absorption and a CO2 loading of 0.32 mol CO2 / mol MEA was sequentially added dropwise to the hydrophobic stainless steel sheets, and the contact angle was measured using an automatic optical contact angle meter.

[0063] Table 1

[0064] As shown in Table 1, the coating formed by the hydrophobic coating prepared in this invention has a contact angle of more than 112° with the MEA solution that has absorbed carbon dioxide. This indicates that the coating formed by the hydrophobic coating prepared in this invention has good hydrophobicity with the MEA solution that has absorbed carbon dioxide and can promote the desorption of carbon dioxide.

[0065] Test Example 2 The hydrophobic coatings prepared in Examples 1-5 and Comparative Examples 1-2 were sprayed onto the surface of 304L stainless steel sheets to obtain hydrophobic stainless steel sheets. The wear resistance of the hydrophobic stainless steel sheets was tested using a TABER wear resistance tester.

[0066] The hydrophobic stainless steel sheet was placed in the center of a horizontal platform and rotated at a speed of (60±5) r / min. Two grinding wheels (rubber wheels) were subjected to a specific pressure (pressure: (250±10) g) and pressed onto the test piece for rotation. After 1 minute, the hydrophobic stainless steel sheet was weighed, and the mass change of the hydrophobic stainless steel sheet before and after the test was calculated, i.e., the weight loss rate.

[0067] Table 1

[0068] As shown in Table 1, the hydrophobic stainless steel sheet prepared by the method of the present invention has a mass loss of less than 0.08% and has excellent wear resistance.

[0069] Test Example 3 The hydrophobic coatings prepared in Examples 1-5 and Comparative Examples 1-2 were sprayed onto the surface of 304L stainless steel sheets to obtain hydrophobic stainless steel sheets. The hydrophobic stainless steel sheets were then rinsed with a MEA solution at 100°C (containing carbon dioxide and a CO2 loading of 0.32 mol CO2 / mol MEA) at a flow rate of 40 L / h for 30 min. Afterwards, a wear resistance test was conducted according to Test Example 2, and the test results are shown in Table 2.

[0070] Table 2

[0071] As shown in Table 2, the hydrophobic stainless steel sheets prepared by the method of this invention still exhibit excellent wear resistance after being rinsed with a high-temperature MEA solution. Furthermore, compared to Table 1, the reduction in weight loss rate in Examples 1-5 is less than 0.01%, essentially unchanged. This indicates that the hydrophobic stainless steel sheet coating prepared by the method of this invention is stable and possesses good adsorption properties, thermal stability, and corrosion resistance.

[0072] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A hydrophobic coating, characterized in that, The hydrophobic coating comprises: 1 part by weight of adhesive, 0.08-0.25 parts by weight of curing agent, 0.1-0.5 parts by weight of alkali-modified vinylidene fluoride copolymer, 0.001-0.15 parts by weight of fluorinated inorganic filler, and 2-8 parts by weight of coating solvent.

2. The hydrophobic coating according to claim 1, wherein, The adhesive is selected from solid resins, preferably from one or more of epoxy resins, polyamide resins, and acrylic resins, and more preferably from epoxy resins.

3. The hydrophobic coating according to claim 1 or 2, wherein, The curing agent is selected from one or more of polyamide, m-phenylenediamine, tributyl phosphate, triphenyl phosphate, and diphenyl octyl phosphate, preferably m-phenylenediamine.

4. The hydrophobic coating according to any one of claims 1-3, wherein, The preparation method of the alkali-modified vinylidene fluoride copolymer includes: adding the vinylidene fluoride copolymer to an alkaline solution for modification treatment to obtain the alkali-modified vinylidene fluoride copolymer.

5. The hydrophobic coating according to claim 4, wherein, The vinylidene fluoride copolymer is a vinylidene fluoride monomer copolymer and / or a copolymer of vinylidene fluoride monomer and tetrafluoroethylene monomer, preferably a vinylidene fluoride monomer copolymer. Preferably, the alkaline solution is selected from one or more of sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, and ammonia aqueous solution, and is preferably sodium hydroxide aqueous solution; Preferably, the mass concentration of alkali in the alkaline solution is 2-8%, more preferably 4-6%; Preferably, the mass ratio of the vinylidene fluoride copolymer to the alkaline solution is 1:150-250, more preferably 1g:180-220; Preferably, the modification treatment temperature is room temperature, and the modification treatment time is 8-16 hours, preferably 10-14 hours.

6. The hydrophobic coating according to any one of claims 1-5, wherein, The fluorinated inorganic filler is selected from one or more of fluorinated silicon dioxide, fluorinated aluminum hydroxide, fluorinated magnesium hydroxide, fluorinated calcium carbonate, fluorinated kaolin, fluorinated titanium dioxide, and fluorinated graphene oxide, preferably fluorinated silicon dioxide.

7. The hydrophobic coating according to claim 6, wherein, The preparation method of the fluorinated inorganic filler includes: spray drying a suspension containing inorganic filler and PFAS to obtain the fluorinated inorganic filler; Preferably, the PFAS is selected from one or more of perfluorooctyltrichlorosilane, 1H,1H,2H,2H-perfluorooctyltriethoxysilane, perfluorooctyltrimethoxysilane, and perfluorooctylethoxysilane, and is more preferably perfluorooctyltrichlorosilane; Preferably, the mass ratio of the inorganic filler to PFAS is 1:0.01-0.05, more preferably 1:0.02-0.03; Preferably, the spray drying temperature is 100-150℃, and more preferably 110-130℃.

8. A method for preparing a hydrophobic filler, characterized in that, The method includes spraying the hydrophobic coating according to any one of claims 1-7 onto the filler matrix and then drying it to obtain the hydrophobic filler.

9. A hydrophobic filler prepared by the method of claim 8.

10. The application of the hydrophobic filler according to claim 9 in carbon dioxide capture.

Images