Multifunctional liquid-like coatings, methods for their preparation and their use in the field of antifouling and / or drag reduction

Abstract

The present application belongs to the technical field of coating, and relates to a multifunctional liquid-like coating, a preparation method thereof and application of the multifunctional liquid-like coating in the field of antifouling and / or drag reduction. The multifunctional liquid-like coating is arranged on a substrate surface and comprises an intermediate layer and a polymer brush. The intermediate layer is arranged between the substrate and the polymer brush. The material of the intermediate layer is polysiloxane, and the polysiloxane is connected to the substrate surface through a chemical bond. The polymer brush is formed by polymerization of a polyfluorosilane and dimethyldimethoxysilane. The multifunctional liquid-like coating provided by the present application not only has excellent broad-spectrum liquid repellency and drag reduction performance, but also can significantly enhance the antifouling ability of the substrate surface. Meanwhile, the multifunctional liquid-like coating provided by the present application has good mechanical stability under extreme conditions such as high temperature, high humidity and mechanical wear, and has a wide application prospect in the fields of aerospace, marine equipment and electronic devices.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coating, and relates to a multifunctional liquid-like coating, a preparation method thereof and application thereof in the fields of antifouling and / or drag reduction. BACKGROUND

[0002] The information disclosed in this BACKGROUND section is only for the purpose of increasing the understanding of the general background of the present application and should not be taken as an acknowledgement or any form of suggestion that this information forms prior art with respect to any country.

[0003] The core design strategy of the liquid-like coating is to construct a dynamic molecular layer on the smooth substrate surface by covalently grafting polymer molecular brushes with high flexibility. Such high-flexibility molecular chains endow the surface with dynamic fluidity, enabling liquid droplets to rapidly slide on the low-stiction interface at a very low sliding angle. Meanwhile, the covalent anchoring mechanism ensures the mechanical stability of the liquid-like surface. With these unique advantages, the liquid-like coating exhibits great application potential in the fields of antifouling, droplet transportation and membrane separation, etc.

[0004] Polydimethylsiloxane (PDMS) liquid-like coatings are widely used due to their excellent liquid-repellent performance, exhibiting a very low sliding angle for high-surface-tension liquids such as water and oil. However, due to their own surface energy, such coatings are difficult to effectively repel low-surface-energy liquids such as n-hexane, limiting their application potential in the field of organic solvent processing. To endow the surface with excellent liquid-repellent ability for low-surface-energy liquids, fluorosilane is used to prepare a liquid-like surface that can effectively repel low-surface-energy liquids, but the sliding angle of the obtained liquid droplets is usually greater than that of the PDMS liquid-like coating. Therefore, the existing liquid-like coating is difficult to simultaneously achieve low sliding angle and high liquid-repellent universality. In addition, the traditional liquid-like coating can only be prepared on silicon-containing substrate surfaces such as glass and silicon wafer, and is difficult to be realized on other material substrates such as metal; at the same time, due to the thin thickness of the traditional liquid-like coating, its mechanical stability is poor. SUMMARY

[0005] In order to solve the problems in the prior art, the present application aims to provide a multifunctional liquid-like coating, a preparation method thereof and application thereof in the fields of antifouling and / or drag reduction. The multifunctional liquid-like coating provided by the present application not only has excellent broad-spectrum liquid-repellent property (n-hexane sliding angle less than 3°) and drag reduction performance, but also has excellent repelling characteristics for multi-state pollutants (including solid particles, organic liquids and biological pollutants, etc.), which can significantly enhance the antifouling ability of the substrate surface. At the same time, the multifunctional liquid-like coating provided by the present application exhibits good mechanical stability under extreme conditions such as high temperature, high humidity and mechanical wear, and has broad application prospects in the fields of aerospace, marine equipment and electronic devices.

[0006] In order to achieve the above-mentioned purposes, the technical scheme of the present application is:

[0007] The first aspect relates to a multifunctional liquid-like coating, which is arranged on a substrate surface, and comprises an intermediate layer and a polymer brush, wherein the intermediate layer is arranged between the substrate and the polymer brush, the material of the intermediate layer is polysiloxane, and the polysiloxane is connected to the substrate surface by a chemical bond, and the polymer brush is formed by polymerization of a polyfluorosilane and dimethyldimethoxysilane; wherein the polyfluorosilane contains at least one polyfluoroalkyl group and at least two alkoxy groups, the polyfluoroalkyl group is an alkyl group in which at least 70% of hydrogen atoms are replaced by fluorine atoms, and the carbon number of the polyfluoroalkyl group is 6-20.

[0008] The second aspect relates to the multifunctional liquid-like coating, which comprises the following steps:

[0009] A substrate is provided, and the surface of the substrate is pretreated to expose hydroxyl groups on the surface;

[0010] A first mixed solution is obtained by mixing a tetraalkoxysilane, a silane coupling agent and a first catalyst in a solvent, the first mixed solution is coated on the surface of the pretreated substrate, and a heating reaction is performed; the tetraalkoxysilane and the silane coupling agent are subjected to a polymerization reaction, and the silane coupling agent is reacted with the hydroxyl groups on the surface of the substrate, so that the intermediate layer with a polysiloxane material is formed on the surface of the substrate; the silane coupling agent contains an epoxy group and at least two alkoxy groups.

[0011] A second mixed solution is obtained by mixing a polyfluorosilane, dimethyldimethoxysilane and a second catalyst in a solvent, and the second mixed solution is coated on the surface of the intermediate layer, and a catalytic polymerization reaction is performed to form a polymer brush on the surface of the intermediate layer.

[0012] The silane coupling agent used in the present application contains an epoxy group, which can react with hydroxyl groups on the surface of a substrate without silicon to realize the chemical bond between the intermediate layer and the substrate, thereby ensuring the arrangement of the polymer brush on the surface of the substrate without silicon, and enhancing the mechanical stability of the multifunctional liquid-like coating.

[0013] The third aspect relates to the application of the multifunctional liquid-like coating in the field of antifouling and / or drag reduction.

[0014] The present application has the following advantages:

[0015] 1. The present application forms an intermediate layer with a polysiloxane material on the surface of the substrate first, which not only can be combined with any substrate surface, but also can provide active sites for the subsequent grafting of the polymer brush, thereby ensuring the stability of the multifunctional liquid-like coating under extreme conditions such as high temperature, high humidity and mechanical wear.

[0016] 2、The application can realize the synergistic optimization of the low sliding angle of the substrate surface and the broad-spectrum liquid repellency by copolymerization of dimethyl dimethoxysilane and perfluorosilane on the basis of the intermediate layer, and experiments show that the surface sliding performance has good underwater drag reduction effect. The liquid repellent coating has excellent drag reduction performance and broad-spectrum antifouling characteristics, can effectively repel the adhesion of different surface energy liquid, solid particle pollutants and microorganisms, and significantly improves the application performance of the coating in complex environments. BRIEF DESCRIPTION OF DRAWINGS

[0017] The drawings accompanying the specification of this application form a part thereof, serve to provide further understanding of the application, and together with the description, explain the application. The specific embodiments of the application and its description are used to explain the application without imposing undue limitation on the application.

[0018] Figure 1 Preparation process and mechanism diagram of the liquid-like coating prepared for examples 1-5 of the application.

[0019] Figure 2 Comparison of sliding angles of liquid droplets with different surface tensions on the liquid-like coating prepared for examples 1-5 of the application.

[0020] Figure 3 Comparison of drag reduction effects of the liquid-like coating prepared for examples 1-5 of the application; (a) is the drag reduction effect of the liquid-like coating prepared for examples 1-5 at different rotation speeds (0 to 300 revolutions per minute), (b) is the drag reduction effect of the liquid-like coating prepared for examples 1-5 at a rotation speed of 300 revolutions per minute.

[0021] Figure 4 Comparison of antifouling effects of the liquid-like coating prepared for examples 1-5 of the application; (a) is Staphylococcus aureus, (b) is Escherichia coli, and (c) is diatom.

[0022] Figure 5 Stability test results of the liquid-like coating prepared for example 3 of the application under different conditions; (a) is ultraviolet irradiation, (b) is ultrasonic treatment, (c) is salt solution treatment, (d) is heating treatment, (e) is freezing treatment, and (f) is shear friction. DETAILED DESCRIPTION

[0023] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the application belongs.

[0024] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0025] In view of the fact that the existing liquid-like coating is difficult to achieve low sliding angle and high liquid repellency at the same time, and the mechanical stability is poor, the present application provides a multifunctional liquid-like coating, a preparation method thereof and its application in the field of antifouling and / or drag reduction.

[0026] In a typical embodiment of the present application, a multifunctional liquid-like coating is provided, which is arranged on the surface of a substrate and comprises an intermediate layer and a polymer brush. The intermediate layer is arranged between the substrate and the polymer brush. The material of the intermediate layer is polysiloxane, and the polysiloxane is connected to the surface of the substrate by a chemical bond. The polymer brush is formed by polymerization of a multifluorosilane and dimethyldimethoxysilane. The multifluorosilane contains at least one multifluoroalkyl group and at least two alkoxy groups. The multifluoroalkyl group is an alkyl group in which at least 70% of the hydrogen atoms are replaced by fluorine atoms. The number of carbon atoms in the multifluoroalkyl group is 6-20.

[0027] In some embodiments, the multifluoroalkyl group is an alkyl group in which 70-85% of the hydrogen atoms are replaced by fluorine atoms.

[0028] In some embodiments, the multifluorosilane contains one multifluoroalkyl group, one methyl group, and two alkoxy groups.

[0029] In some embodiments, the number of carbon atoms in the multifluoroalkyl group is 6-14, preferably 6-10.

[0030] In some embodiments, the multifluorosilane is 1H, 1H, 2H, 2H-perfluorooctylmethyldimethoxysilane (abbreviated as perfluorooctylmethyldimethoxysilane).

[0031] In some embodiments, the mass ratio of the multifluorosilane to dimethyldimethoxysilane is 0.3-3:1, preferably 0.5-2.5:1, preferably 0.5-2:1, further preferably 0.5-1.5:1, more further preferably 0.8-1.2:1 or 0.9-1.1:1.

[0032] Another embodiment of the present application provides a multifunctional liquid-like coating as described above, comprising the following steps:

[0033] A substrate is provided, and the surface of the substrate is pretreated to expose hydroxyl groups on the surface;

[0034] The tetraalkoxysilane, silane coupling agent and first catalyst are mixed in a solvent to obtain a first mixed solution, the first mixed solution is coated on the surface of the pretreated substrate, and a heating reaction is performed; the tetraalkoxysilane and the silane coupling agent are subjected to a polymerization reaction, and the silane coupling agent reacts with the hydroxyl groups on the surface of the substrate, so that the intermediate layer on the surface of the substrate is formed of polysiloxane; the silane coupling agent contains an epoxy group and at least two alkoxy groups.

[0035] The polyfluorosilane, dimethyldimethoxysilane and second catalyst are mixed in a solvent to obtain a second mixed solution, the second mixed solution is coated on the surface of the intermediate layer, and a catalytic polymerization reaction is performed to form a polymer brush on the surface of the intermediate layer.

[0036] In some embodiments, the pretreatment utilizes one or more of a plasma treatment, ultraviolet irradiation, an otocinclus solution treatment, and an alkali treatment.

[0037] In some embodiments, the alkoxy group in the tetraalkoxysilane is a C1-C6 alkoxy group, preferably a C1-C3 alkoxy group. C1 refers to a carbon number of 1, C3 refers to a carbon number of 3, and C6 refers to a carbon number of 6.

[0038] In some embodiments, the silane coupling agent is KH560.

[0039] In some embodiments, the first catalyst is formic acid.

[0040] In some embodiments, the volume ratio of the tetraalkoxysilane to the silane coupling agent is 1:1-3.

[0041] In some embodiments, the tetraalkoxysilane, silane coupling agent and first catalyst are pre-polymerized in a solvent to obtain a first mixed solution. The pre-polymerization time is 10-14 hours. The solvent in the first mixed solution is an alcohol-water solution, and the mass ratio of the alcohol-water solution is 85:15-95:5.

[0042] In some embodiments, the heating reaction is performed at a temperature of 70-90°C.

[0043] In some embodiments, the method of coating the first mixed solution on the surface of the pretreated substrate is spraying, spin coating or dipping. By adjusting the number of coatings, the thickness of the intermediate layer can be accurately controlled.

[0044] In some embodiments, the second catalyst is sulfuric acid.

[0045] A third embodiment of the present application provides a use of the above-mentioned multifunctional liquid-like coating in the field of antifouling and / or drag reduction.

[0046] In order for those skilled in the art to more clearly understand the technical solutions of the present application, the technical solutions of the present application will be described below in detail with specific examples.

[0047] Example 1

[0048] A method for preparing a multifunctional liquid-like coating, as shown in Figure 1 comprises the following steps:

[0049] (1) The titanium alloy substrate was sequentially placed in deionized water and anhydrous ethanol for ultrasonic treatment for 10 minutes, respectively, and then taken out and dried. The dried titanium alloy substrate was subjected to plasma treatment for 15 minutes to activate the titanium alloy surface.

[0050] (2) 1 mL of tetraethoxysilane was mixed with 2 mL of silane coupling agent KH560, added to 30 mL of 90% mass fraction ethanol aqueous solution, and 0.5 mL of formic acid was added as a catalyst to prepare a mixed solution. The mixed solution was allowed to stand for 12 hours to complete the prepolymerization reaction. Subsequently, the prepolymerized mixed solution was uniformly coated on the activated titanium alloy surface obtained in step (1) by spin coating, and heated at 80°C for 5 minutes to form a polysiloxane intermediate layer.

[0051] (3) 1 mL of dimethyldimethoxysilane was added to 10 mL of isopropanol, and 0.1 mL of sulfuric acid was added as a catalyst to prepare a mixed solution. The mixed solution was uniformly coated on the surface of the polysiloxane intermediate layer of the titanium alloy surface obtained in step (2) by dip coating. After the sample was dried at room temperature, it was sequentially placed in deionized water and isopropanol for cleaning, and then taken out and dried at room temperature after cleaning, to finally obtain a multifunctional liquid-like coating, named 4Si / 0F.

[0052] Example 2

[0053] A method for preparing a multifunctional liquid-like coating, as shown in Figure 1 comprises the following steps:

[0054] (1) The titanium alloy substrate was sequentially placed in deionized water and anhydrous ethanol for ultrasonic treatment for 10 minutes, respectively, and then taken out and dried. The dried titanium alloy substrate was subjected to plasma treatment for 15 minutes to activate the titanium alloy surface.

[0055] (2) 1 mL of tetraethoxysilane was mixed with 2 mL of silane coupling agent KH560, added to 30 mL of 90% mass fraction ethanol aqueous solution, and 0.5 mL of formic acid was added as a catalyst to prepare a mixed solution. The mixed solution was allowed to stand for 12 hours to complete the prepolymerization reaction. Subsequently, the mixed solution after prepolymerization was uniformly coated on the activated titanium alloy surface obtained in step (1) by using a spin coating method, and heated at 80°C for 5 minutes to form a polysiloxane intermediate layer.

[0056] (3) 1 mL of dimethyldimethoxysilane and perfluorooctylmethyldimethoxysilane were mixed in a mass ratio of 3:1, added to 10 mL of isopropyl alcohol, and 0.1 mL of sulfuric acid was added as a catalyst to prepare a mixed solution. The mixed solution was uniformly coated on the surface of the polysiloxane intermediate layer of the titanium alloy surface obtained in step (2) by using a dip coating method. After the sample was dried at room temperature, it was sequentially placed in deionized water and isopropyl alcohol for cleaning, taken out after cleaning was completed, and dried at room temperature, finally obtaining a multifunctional liquid-like coating, named 3Si / 1F.

[0057] Example 3

[0058] A method for preparing a multifunctional liquid-like coating, as shown in Figure 1 , includes the following steps:

[0059] (1) The titanium alloy substrate was sequentially placed in deionized water and anhydrous ethanol, and ultrasonic treatment was performed for 10 minutes, respectively, and then taken out and dried. The dried titanium alloy substrate was subjected to plasma treatment for 15 minutes to activate the titanium alloy surface.

[0060] (2) 1 mL of tetraethoxysilane was mixed with 2 mL of silane coupling agent KH560, added to 30 mL of 90% mass fraction ethanol aqueous solution, and 0.5 mL of formic acid was added as a catalyst to prepare a mixed solution. The mixed solution was allowed to stand for 12 hours to complete the prepolymerization reaction. Subsequently, the mixed solution after prepolymerization was uniformly coated on the activated titanium alloy surface obtained in step (1) by using a spin coating method, and heated at 80°C for 5 minutes to form a polysiloxane intermediate layer.

[0061] (3) 1 mL of dimethyldimethoxysilane and perfluorooctylmethyldimethoxysilane were mixed in a mass ratio of 2 / 2, added to 10 mL of isopropyl alcohol, and 0.1 mL of sulfuric acid was added as a catalyst to prepare a mixed solution. The mixed solution was uniformly coated on the surface of the polysiloxane intermediate layer of the titanium alloy surface obtained in step (2) by using a dip coating method. After the sample was dried at room temperature, it was sequentially placed in deionized water and isopropyl alcohol for cleaning, taken out after cleaning was completed, and dried at room temperature, finally obtaining a multifunctional liquid-like coating, named 2Si / 2F.

[0062] Example 4

[0063] A method for preparing a multifunctional liquid-like coating, as shown in Figure 1 , comprising the following steps:

[0064] (1) The titanium alloy substrate was sequentially placed in deionized water and anhydrous ethanol for ultrasonic treatment for 10 minutes, respectively, and then taken out and dried. The dried titanium alloy substrate was subjected to plasma treatment for 15 minutes to activate the titanium alloy surface.

[0065] (2) 1 mL of tetraethoxysilane was mixed with 2 mL of silane coupling agent KH560, added to 30 mL of 90% ethanol aqueous solution, and 0.5 mL of formic acid was added as a catalyst to prepare a mixed solution. The mixed solution was allowed to stand for 12 hours to complete the prepolymerization reaction. Subsequently, the prepolymerized mixed solution was uniformly coated on the activated titanium alloy surface obtained in step (1) by spin coating, and heated at 80°C for 5 minutes to form a polysiloxane intermediate layer.

[0066] (3) Dimethyl dimethoxy silane and perfluorooctyl methyl dimethoxy silane were mixed in a mass ratio of 1 / 3, 1 mL of the mixed solution was added to 10 mL of isopropanol, and 0.1 mL of sulfuric acid was added as a catalyst to prepare a mixed solution. The mixed solution was uniformly coated on the surface of the polysiloxane intermediate layer of the titanium alloy surface obtained in step (2) by dip coating. After the sample was dried at room temperature, it was sequentially placed in deionized water and isopropanol for cleaning, and then taken out and dried at room temperature after cleaning was completed, to finally obtain a multifunctional liquid-like coating, named 1Si / 3F.

[0067] Example 5

[0068] A method for preparing a multifunctional liquid-like coating, as shown in Figure 1 , comprising the following steps:

[0069] (1) The titanium alloy substrate was sequentially placed in deionized water and anhydrous ethanol for ultrasonic treatment for 10 minutes, respectively, and then taken out and dried. The dried titanium alloy substrate was subjected to plasma treatment for 15 minutes to activate the titanium alloy surface.

[0070] (2) 1 mL of tetraethoxysilane was mixed with 2 mL of silane coupling agent KH560, added to 30 mL of 90% ethanol aqueous solution, and 0.5 mL of formic acid was added as a catalyst to prepare a mixed solution. The mixed solution was allowed to stand for 12 hours to complete the prepolymerization reaction. Subsequently, the prepolymerized mixed solution was uniformly coated on the activated titanium alloy surface obtained in step (1) by spin coating, and heated at 80°C for 5 minutes to form a polysiloxane intermediate layer.

[0071] (3) 1 mL of perfluorooctylmethyl dimethoxysilane was added to 10 mL of isopropyl alcohol, and 0.1 mL of sulfuric acid was added as a catalyst to prepare a mixed solution. The mixed solution was uniformly coated on the surface of the polysiloxane intermediate layer of the titanium alloy surface obtained in step (2) by dip coating. After the sample was dried at room temperature, it was sequentially cleaned in deionized water and isopropyl alcohol, taken out after cleaning, and dried at room temperature, and finally a multifunctional liquid-like coating was obtained, named 0Si / 4F.

[0072] Performance detection:

[0073] The sliding angle of the liquid-like coating was tested by the inclined platform method to characterize the repellency of the liquid-like coating to different surface tension liquids (including deionized water, PAO4 base oil, toluene, isopropyl alcohol, and n-hexane). The specific operation was as follows: the inclination angle of the substrate was systematically increased until the liquid droplet began to slide, and the angle recorded at this time was the sliding angle of the liquid droplet.

[0074] As shown in Figure 2 , with the increase of the proportion of fluorine-containing monomers, the sliding angle of the liquid droplet on the surface of the liquid-like coating showed a trend of first decreasing and then increasing, and 2Si / 2F had the lowest sliding angle (water sliding angle 8°, PAO4 base oil sliding angle 7°, toluene sliding angle 5°, isopropyl alcohol sliding angle 4°, and n-hexane sliding angle 2°), which proved that it had the best liquid-repellent effect.

[0075] The results show that the liquid-like coating developed by the present application can significantly reduce the sliding angle of the liquid droplet on the substrate and improve the repellency of the substrate to low surface tension liquids.

[0076] The drag reduction effect of the liquid-like coating was tested by using a high-precision rheometer. The specific test method was as follows: the blank titanium alloy substrate without coating and the titanium alloy coated with the liquid-like coating were respectively attached to the bottom of the container opposite the rheometer disc, and the distance between the sample and the rheometer disc was accurately 2 mm. Then, the rotation speed of the disc was gradually increased from 0 to 300 rpm, and the torque of the disc was measured at a rotation speed of 300 rpm for a period of time. By comparing the torque values of different surface samples and blank samples under the same conditions, the drag reduction rate was calculated.

[0077] As shown in Figure 3 , at a rotation speed of 0 to 300 rpm, with the increase of the proportion of fluorine-containing monomers, the drag reduction rate of the liquid-like coating showed a trend of first increasing and then decreasing when the rotation speed reached 300 rpm, and 2Si / 2F had the highest drag reduction rate (7.3%), which proved that it had the best drag reduction effect.

[0078] The results show that the liquid-like coating developed by the present application has good drag reduction effect.

[0079] The anti-fouling effect of different surfaces was tested by using an anti-microbial adhesion experiment to verify the anti-fouling effect of the liquid-like coating. Specifically, a blank titanium alloy substrate without coating and a titanium alloy coated with a liquid-like coating were immersed in a microbial culture solution, and after incubation for a period of time, the sample surface was rinsed with deionized water to remove loosely adsorbed microorganisms. Then the sample was ultrasonically rinsed with deionized water to obtain the microorganisms adsorbed on the sample, and the microbial desorption solution was coated on an agar plate and incubated for 12 hours. Finally, the anti-fouling performance of different samples was evaluated by the number of microorganisms on the corresponding agar plate.

[0080] As shown in the results Figure 4 , with the increase of the proportion of fluorine-containing monomers, the amount of microorganisms attached to the surface of the liquid-like coating showed a trend of first decreasing and then increasing, and 2Si / 2F had the lowest amount of microorganism attachment, proving that it had the best anti-fouling effect, because the 2Si / 2F coating had both high molecular chain movement characteristics and low surface energy.

[0081] The results show that the liquid-like coating developed by the present application can effectively resist the adhesion of microorganisms.

[0082] To systematically evaluate the durability and stability of the liquid-like coating, the following tests were performed on the sample coated with the liquid-like coating (2Si / 2F): ultraviolet light irradiation (395 nm, 360 W, 24 h), ultrasonic cleaning (240 W, 24 h), salt water immersion (3.5 wt% sodium chloride solution, 168 h), boiling water immersion (100℃, 168 h), low temperature freezing (-18℃, 168 h), and friction and abrasion (4 kPa, 100 cycles). Subsequently, the change in the sliding angle of different liquid droplets on the surface of the liquid-like coating was measured.

[0083] As shown in the results Figure 5 , after the above tests, the sliding angle of various liquid droplets on the surface of the liquid-like coating did not change substantially (sliding angle change <2°), proving that the liquid-like coating developed by the present application has extremely excellent stability.

[0084] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for producing a multifunctional liquid-like coating, characterized by, The method comprises the following steps: providing a substrate and pre-treating the surface of the substrate to expose hydroxyl groups on the surface; adding tetraalkoxysilane, silane coupling agent and first catalyst into a solvent to obtain a first mixed solution, coating the first mixed solution on the surface of the pre-treated substrate and heating to react; the tetraalkoxysilane and the silane coupling agent are subjected to polymerization reaction, and the silane coupling agent reacts with the hydroxyl groups on the surface of the substrate to form an intermediate layer of polysiloxane on the surface of the substrate; the silane coupling agent contains an epoxy group and at least two alkoxy groups; adding polyfluorosilane, dimethyldimethoxysilane and second catalyst into a solvent to obtain a second mixed solution, coating the second mixed solution on the surface of the intermediate layer and subjecting to catalytic polymerization reaction to form a polymer brush on the surface of the intermediate layer; the multifunctional liquid-like coating is arranged on the surface of a substrate and comprises an intermediate layer and a polymer brush, the intermediate layer is arranged between the substrate and the polymer brush, the material of the intermediate layer is polysiloxane, the polysiloxane is connected to the surface of the substrate by a chemical bond, and the polymer brush is formed by polymerization of the polyfluorosilane and the dimethyldimethoxysilane; wherein the polyfluorosilane contains at least one polyfluoroalkyl group and at least two alkoxy groups, the polyfluoroalkyl group is an alkyl group in which at least 70% of hydrogen atoms are replaced by fluorine atoms, and the number of carbon atoms in the polyfluoroalkyl group is 6-10.

2. The production method according to claim 1, wherein The polyfluoroalkyl group is an alkyl group in which 70-85% of hydrogen atoms are replaced by fluorine atoms. alternatively, the polyfluorosilane contains one polyfluoroalkyl group, one methyl group and two alkoxy groups; alternatively, the polyfluorosilane is 1H, 1H, 2H, 2H-perfluorooctylmethyldimethoxysilane.

3. The production method according to claim 1, wherein The mass ratio of the polyfluorosilane to the dimethyldimethoxysilane is 0.3-3:

1.

4. The production method according to claim 3, wherein The mass ratio of the polyfluorosilane to the dimethyldimethoxysilane is 0.5-2.5:

1.

5. The production method according to claim 3, wherein The mass ratio of the polyfluorosilane to the dimethyldimethoxysilane is 0.5-2:

1.

6. The production method according to claim 3, wherein The mass ratio of the polyfluorosilane to the dimethyldimethoxysilane is 0.5-1.5:

1.

7. The production method according to claim 3, wherein The mass ratio of the polyfluorosilane to the dimethyldimethoxysilane is 0.8-1.2:

1.

8. The production method according to claim 3, wherein The mass ratio of the polyfluorosilane to the dimethyldimethoxysilane is 0.9-1.1:

1.

9. The production method according to claim 1, wherein The pre-treatment method is one or more of plasma treatment, ultraviolet irradiation, piranha solution treatment and alkali treatment.

10. The production method according to claim 1, wherein The alkoxy groups in the tetraalkoxysilane are C1-C6 alkoxy groups. alternatively, the silane coupling agent is KH560.

11. The production method according to claim 10, wherein the production method is characterized by The alkoxy groups in the tetraalkoxysilane are C1-C3 alkoxy groups.

12. The production method according to claim 1, wherein The first catalyst is formic acid.

13. The production method according to claim 1, wherein The volume ratio of the tetraalkoxysilane to the silane coupling agent is 1:1-3.

14. The production method according to claim 1, wherein The tetraalkoxysilane, the silane coupling agent and the first catalyst are added into a solvent to pre-polymerize to obtain the first mixed solution; alternatively, the heating temperature is 70-90 ℃.

15. The production method according to claim 1, wherein The method for coating the first mixed solution on the surface of the pre-treated substrate is spraying, spin coating or dipping. alternatively, the second catalyst is sulfuric acid.

16. A multi-functional liquid-like coating characterized by, obtained by the preparation method of any one of claims 1-15.

17. Use of the multifunctional liquid-like coating of claim 16 in the field of antifouling and / or drag reduction.

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