A super-hydrophobic multifunctional coating and a method for preparing the same

Abstract

The present application relates to the technical field of coating material, in particular to a super-hydrophobic multifunctional coating and a preparation method thereof.The specific technical scheme is as follows: a super-hydrophobic multifunctional coating comprises the following components in terms of volume percentage: 0.1-3.0% of a hydrophobic composition, 1.5-12% of a texture stabilizer, 17-60% of a binder, and 25-80% of an alcohol-free base material.The multifunctional coating has the characteristics of high hydrophobicity, a high contact angle of 160±5°, a rolling angle of ≤5°, oil-repellent performance, corrosion resistance to media, chemical inertness, low surface tension, etc., and does not require pretreatment of the material, and can improve the surface physical and chemical characteristics of various materials.

Description

Technical Field

[0001] This invention relates to the field of coating materials technology, specifically to a superhydrophobic multifunctional coating and its preparation method. Background Technology

[0002] Patent RU 2601339 reports a method for preparing a superhydrophobic coating using an aqueous solvent. The drawback of this method is that it uses water as the substrate material. Furthermore, its main hydrophobic components consist primarily of water-dispersible fluorinated and perfluorinated polymers, as well as hydrophilic nanoparticles. Moreover, the preparation of this superhydrophobic composition is cumbersome and its composition is complex.

[0003] One known method for improving coating performance using fluorinated silanes (US6737105, RU2149151, US7425279). A drawback of this method is the relatively small water contact angle (90-104°) when the coating thickness is 10 nm.

[0004] A method for preparing hydrophobic coatings using silane (alkoxysilane) modified perfluoropolyethers is known (US7196212, US7413807). A drawback of this method is that although a water contact angle of 114-117° can be achieved with a coating thickness of 0.1-10 nm, the coating does not improve hydrophobicity.

[0005] A method for producing superhydrophobic coatings using fluorinated compounds on surfaces containing hydroxyl groups and other functional groups is known. However, without fluorinated compounds, surface pretreatment with plasma is required. The surface treatment is performed in two stages: first, treatment with chlorosilanes, followed by treatment with fluorinated silanes (EP 0497189). The drawbacks of this method are the use of corrosive compounds and the need for complex high-temperature surface treatment processes. It also places high demands on the surface properties of the original material. Similar to the process and results described in this patent, patent RU240510 also reports a method for preparing superhydrophobic coatings using fluorocarbon silanes as the hydrophobic component and fumed silica as the texture component. One disadvantage of this method is the use of alcohols and other organic solvents as the base material for the hydrophobic composition, which can have a serious adverse effect on the treated surface and limit its application areas. Furthermore, the coating lacks oleophobicity, resulting in an insufficiently small roll-off angle to achieve a "self-cleaning" process. Therefore, this superhydrophobic coating has a short lifespan, insufficient resistance to oxidation and chemical corrosion, and is only suitable for small-scale production. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a superhydrophobic multifunctional coating and its preparation method. Specifically, it provides a multifunctional superhydrophobic coating that does not require surface pretreatment, can be applied to different substrates, and simultaneously possesses oleophobic properties, low roll-off angle and self-cleaning ability, non-corrosiveness, long-lasting superhydrophobicity and oleophobicity, and resistance to chemical media erosion and oxidation.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] This invention discloses a superhydrophobic multifunctional coating, which comprises the following components by volume percentage: 0.1-3.0% hydrophobic composition, 1.5-12% texture stabilizer, 17-60% binder, and 25-80% alcohol-free base material.

[0009] Preferably, the hydrophobic composition comprises a fluorocarbon silane with the molecular formula CxHyF 13 O3Si, where x is an integer from 10 to 15 and y is an integer from 12 to 20.

[0010] Preferably, the hydrophobic composition further includes polymethylsiloxane with a viscosity of 200-1000 cst.

[0011] Preferably, the texture stabilizer is silicon dioxide, and the specific surface area of ​​the silicon dioxide is 70-320 m². 2 / g, with an average particle size of ≤5nm.

[0012] Preferably, the adhesive is a polysiloxane, wherein the mass fraction of silicon dioxide is 25-50 wt% and the mass fraction of tetraethoxysilane is 10-70 wt%.

[0013] Preferably, the alcohol-free substrate material is polymethylcyclosiloxane, wherein the polymethylcyclosiloxane is Dx, and x is an integer from 4 to 5.

[0014] Correspondingly, a method for preparing a superhydrophobic multifunctional coating involves stirring and mixing a hydrophobic composition, a texture stabilizer, a binder, and an alcohol-free substrate material to synthesize a superhydrophobic coating solution.

[0015] Preferably, the substrate is immersed in the prepared superhydrophobic coating solution for 1 to 36 hours, and then the immersed substrate is taken out and dried by blowing at a temperature of 17 to 100°C and an air flow rate of 10 to 40 L / s to obtain a multifunctional superhydrophobic coating.

[0016] The present invention has the following beneficial effects:

[0017] The multifunctional, superhydrophobic coating provided by this invention has the following characteristics: high hydrophobicity, long-term stability, contact angle ≥160±5°, oleophobic properties, roll-off angle ≤5°, resistance to corrosive media and corrosion, chemical inertness, and low surface tension. This coating can be used on the surfaces of various substrates such as aluminum and other metal alloys, ceramics, fabrics, and glass, and can improve the physicochemical parameters of the substrate surface without any surface pretreatment. Attached Figure Description

[0018] Figure 1 Water contact angle diagram for the superhydrophobic multifunctional coating MR-D13A;

[0019] Figure 2 Water contact angle diagram for the superhydrophobic multifunctional coating MR-D13S;

[0020] Figure 3 Water contact angle diagram of the superhydrophobic multifunctional coating MR-D13C;

[0021] Figure 4 Water contact angle diagram of the superhydrophobic multifunctional coating MR-D13D;

[0022] Figure 5 Superhydrophobic multifunctional coating Water contact angle diagram;

[0023] Figure 6 Water contact angle diagram for the superhydrophobic multifunctional coating MR-D13W;

[0024] Figure 7 Water contact angle diagram for the superhydrophobic multifunctional coating MR-D13B;

[0025] Figure 8 Superhydrophobic multifunctional coatings MR-D13A, MR-D13S, MR-D13C, MR-D13D The contact angle of MR-D13W and MR-D13B on an aluminum substrate changes over time;

[0026] Figure 9 Superhydrophobic multifunctional coatings MR-D13A, MR-D13S, MR-D13C, MR-D13D The change of the roll angle of MR-D13W and MR-D13B on an aluminum substrate over time. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Unless otherwise specified, the technical means used in the implementation examples are conventional means well known to those skilled in the art.

[0029] This invention discloses a superhydrophobic multifunctional coating, which comprises the following components by volume percentage: 0.1-3.0% hydrophobic composition, 1.5-12% texture stabilizer, 17-60% binder, and 25-80% alcohol-free base material.

[0030] The hydrophobic composition includes a fluorocarbon silane with the molecular formula CxHyF. 13 O3Si, where x is an integer from 10 to 15, y is an integer from 12 to 20, and the volume fraction is 0.5 to 2.0 v / v%. It also includes polymethylsiloxane with a viscosity of 200 to 1000 cst, preferably 200 cst, and the volume fraction of polymethylsiloxane is 0.1 to 1.0 v / v%.

[0031] The texture stabilizer is silica (gas phase), and the specific surface area of ​​the silica is 70–320 m². 2 / g, with an average particle size of ≤5nm. Considering that the density of silica is 0.05g / ml, the volume fraction of 1.5~12v / v% is converted to mass fraction.

[0032] The adhesive is a polysiloxane, wherein the mass fraction of silica is 25-50 wt% and the mass fraction of tetraethoxysilane is 10-70 wt%. The polysiloxane is mainly used in the form of ethyl silicate, with silica weight fractions of 28% and 40%.

[0033] The alcohol-free substrate material is polymethylcyclosiloxane, and the polymethylcyclosiloxane is Dx, where x is an integer from 4 to 5.

[0034] The preparation process of the superhydrophobic multifunctional coating is as follows: the hydrophobic composition, texture stabilizer, binder, and alcohol-free substrate material are sequentially added to a container and stirred until homogeneous. To promote component mixing, a magnetic stirrer with a rotation speed of 700–1200 rpm is used for stirring. This synthesis process is carried out at room temperature and the superhydrophobic coating solution is synthesized in one step.

[0035] When using the coating solution, no additional pretreatment is required on the surface of the material to be treated; it can be used directly. The material to be treated can be glass, ceramics, fabrics, aluminum, and metal alloys, among others. The application process of the synthesized superhydrophobic coating solution can be completed using pneumatic, hydraulic, spraying, or dip coating methods. Complete and defect-free coating can be achieved on any type of material surface.

[0036] When the material to be treated is immersed in the hydrophobic coating solution, it can be immersed for up to 36 hours. Repeated surface treatment can form a multi-layer coating, thereby improving the material's physicochemical parameters: such as increased dielectric properties, high hydrophobicity and stability, a high contact angle ≥160±5°, high oleophobicity, a roll-off angle ≤5°, achieving a "self-cleaning" process, corrosion resistance, chemical inertness, and low surface tension. The treated surface can be dried naturally at room temperature or at a higher temperature. When drying naturally at room temperature, the drying time varies from 0.5 to 48 hours depending on the size of the treated surface. For accelerated drying, the temperature can be 17–100℃, the airflow rate 10–40 L / s, and the drying time 0.005–0.5 hours, allowing the coating to completely cover the material. After the multifunctional superhydrophobic coating is fully formed, the water contact angle parameters of the coating are tested. Subsequently, the coating is placed at room temperature for 168 / 336 / 504 hours, and the water contact angle, coating stability, and roll-off angle are repeatedly measured.

[0037] The present invention will be further described below with reference to specific embodiments.

[0038] Example 1: Preparation of MR-D13A superhydrophobic coating

[0039] A method for preparing a superhydrophobic multifunctional coating, wherein the selected substrate does not require surface pretreatment and can be directly coated, and the following materials are accurately weighed according to the formula: 1 v / v% polymethylsiloxane (viscosity 200 cst) and 0.5 v / v% fluorocarbon silane (molecular formula C 11 H 13 F 13 O3Si); ​​12 v / v% silica (average particle size ≤5nm, density 0.05g / ml); 20 v / v% polysiloxane; 66.5 v / v% decamethylcyclopentasiloxane D5. The above materials were added to a beaker in sequence and mixed evenly with magnetic stirring at 1000 rpm at room temperature to complete the synthesis of superhydrophobic water in one step.

[0040] The surface to be treated requires no additional preparation; materials such as glass, fiber fabric, and aluminum alloy can be used. The substrate is immersed in the coating solution for 4 hours. After immersion, the substrate is removed and can be allowed to dry naturally at room temperature or accelerated artificially. The drying temperature is controlled at 25℃, the airflow rate at 40L / s, and the drying time at 18s to obtain a superhydrophobic multifunctional coating that completely covers the substrate surface. The water contact angle is tested after drying, and then the coating is exposed at room temperature for 168, 336, and 504 hours to analyze its water contact angle, roll-off angle, and stability. The water contact angle is shown in the figure. Figure 1 As shown, the change in the contact angle of the coating on the aluminum substrate over time is shown in the figure. Figure 8 As shown, the change in the roll angle of the coating on the aluminum substrate over time is shown in the figure. Figure 9 As shown.

[0041] Example 2: Preparation of MR-D13S superhydrophobic coating

[0042] A method for preparing a superhydrophobic multifunctional coating, wherein the selected substrate does not require surface pretreatment and can be directly coated, and the following materials are accurately weighed according to the formula: 0.8 v / v% polymethylsiloxane (viscosity 300 cst) and 0.75 v / v% fluorocarbon silane (molecular formula C 11 H 13 F 13 The mixture consisted of: 9.7 v / v% silica (average particle size ≤ 5 nm, density 0.05 g / ml); 30 v / v% polysiloxane; and 58.75 v / v% decamethylcyclotetrasiloxane D4. The above materials were added sequentially to a beaker and mixed uniformly by magnetic stirring at 900 rpm at room temperature, thus completing the one-step synthesis of the superhydrophobic aqueous solution.

[0043] The surface to be treated requires no additional preparation; materials such as glass, fiber fabric, and aluminum alloy can be used. The substrate is immersed in the coating solution for 4 hours. After immersion, the substrate is removed and can be allowed to dry naturally at room temperature or accelerated artificially. The drying temperature is controlled at 25℃, the airflow rate at 40L / s, and the drying time at 18s to obtain a superhydrophobic multifunctional coating that completely covers the substrate surface. The water contact angle is tested after drying, and then the coating is exposed at room temperature for 168, 336, and 504 hours to analyze its water contact angle, roll-off angle, and stability. The water contact angle is shown in the figure. Figure 2 As shown, the change in the contact angle of the coating on the aluminum substrate over time is shown in the figure. Figure 8 As shown, the change in the roll angle of the coating on the aluminum substrate over time is shown in the figure. Figure 9 As shown.

[0044] Example 3: Preparation of MR-D13C superhydrophobic coating

[0045] A method for preparing a superhydrophobic multifunctional coating, wherein the selected substrate does not require surface pretreatment and can be directly coated, and the following materials are accurately weighed according to the formula: 0.6 v / v% polymethylsiloxane (viscosity 300 cst) and 1 v / v% fluorocarbon silane (molecular formula C 11 H 13 F 13 The mixture consisted of: 8.2 v / v% silica (average particle size ≤ 5 nm, density 0.05 g / ml); 40 v / v% polysiloxane; and 50.2 v / v% decamethylcyclotetrasiloxane D4. The above materials were added sequentially to a beaker and mixed uniformly by magnetic stirring at 900 rpm at room temperature, thus completing the one-step synthesis of the superhydrophobic aqueous solution.

[0046] The surface to be treated requires no additional preparation; materials such as glass, fiber fabric, and aluminum alloy can be used. The substrate is immersed in the coating solution for 4 hours. After immersion, the substrate is removed and can be allowed to dry naturally at room temperature or accelerated artificially. The drying temperature is controlled at 25℃, the airflow rate at 40L / s, and the drying time at 18s to obtain a superhydrophobic multifunctional coating that completely covers the substrate surface. The water contact angle is tested after drying, and then the coating is exposed at room temperature for 168, 336, and 504 hours to analyze its water contact angle, roll-off angle, and stability. The water contact angle is shown in the figure. Figure 3 As shown, the change in the contact angle of the coating on the aluminum substrate over time is shown in the figure. Figure 8 As shown, the change in the roll angle of the coating on the aluminum substrate over time is shown in the figure. Figure 9 As shown.

[0047] Example 4: Preparation of MR-D13D superhydrophobic coating

[0048] A method for preparing a superhydrophobic multifunctional coating, wherein the selected substrate does not require surface pretreatment and can be directly coated, and the following materials are accurately weighed according to the formula: 0.6 v / v% polymethylsiloxane (viscosity 200 cst) and 1.25 v / v% fluorocarbon silane (molecular formula C 11 H 13 F 13 O3Si); ​​6.75 v / v% silica (average particle size ≤5 nm, density 0.05 g / ml); 50 v / v% polysiloxane; 41.4 v / v% decamethylcyclopentasiloxane D5. The above materials were added to a beaker in sequence and mixed evenly with magnetic stirring at 950 rpm at room temperature to complete the one-step synthesis of superhydrophobic water solution.

[0049] The surface to be treated requires no additional preparation; materials such as glass, fiber fabric, and aluminum alloy can be used. The substrate is immersed in the coating solution for 2 hours. After immersion, the substrate is removed and can be allowed to dry naturally at room temperature or accelerated artificially. The drying temperature is controlled at 25℃, the airflow rate at 40 L / s, and the drying time at 18 seconds to obtain a superhydrophobic multifunctional coating that completely covers the substrate surface. The water contact angle is tested after the coating dries, and then exposed at room temperature for 168, 336, and 504 hours to analyze the water contact angle, roll-off angle, and stability. The water contact angle is shown in the figure. Figure 4 As shown, the change in the contact angle of the coating on the aluminum substrate over time is shown in the figure. Figure 8 As shown, the change in the roll angle of the coating on the aluminum substrate over time is shown in the figure. Figure 9 As shown.

[0050] Example 5 Preparation of superhydrophobic coatings

[0051] A method for preparing a superhydrophobic multifunctional coating, wherein the selected substrate does not require surface pretreatment and can be directly coated, and the following materials are accurately weighed according to the formula: 0.4 v / v% polymethylsiloxane (viscosity 300 cst) and 1.5 v / v% fluorocarbon silane (molecular formula C 11 H 13 F 13 The mixture consisted of: 5.2 v / v% silica (average particle size ≤ 5 nm, density 0.05 g / ml); 60 v / v% polysiloxane; and 32.9 v / v% decamethylcyclotetrasiloxane D4. The above materials were added sequentially to a beaker and mixed uniformly by magnetic stirring at 800 rpm at room temperature, thus completing the one-step synthesis of the superhydrophobic aqueous solution.

[0052] The surface to be treated requires no additional preparation; materials such as glass, fiber fabric, and aluminum alloy can be used. The substrate is immersed in the coating solution for 2 hours. After immersion, the substrate is removed and can be allowed to dry naturally at room temperature or accelerated artificially. The drying temperature is controlled at 50℃, the airflow rate at 20L / s, and the drying time at 0.015 hours to obtain a superhydrophobic multifunctional coating that completely covers the substrate surface. The water contact angle is tested after drying, and then the coating is exposed at room temperature for 168, 336, and 504 hours to analyze its water contact angle, roll-off angle, and stability. The water contact angle is shown in the figure. Figure 5 As shown, the change in the contact angle of the coating on the aluminum substrate over time is shown in the figure. Figure 8 As shown, the change in the roll angle of the coating on the aluminum substrate over time is shown in the figure. Figure 9 As shown.

[0053] Example 6: Preparation of MR-D13W superhydrophobic coating

[0054] A method for preparing a multifunctional superhydrophobic coating on the surface of a target material, wherein the selected substrate does not require surface pretreatment and can be directly coated, and the following materials are accurately weighed according to the formula: 0.2 v / v% polymethylsiloxane (viscosity 200 cst) and 1.75 v / v% fluorocarbon silane (molecular formula C 11 H 13 F 13 O3Si); ​​3.5 v / v% silica (average particle size ≤5 nm, density 0.05 g / ml); 60 v / v% polysiloxane; 34.55 v / v% decamethylcyclopentasiloxane D5. The above materials were added to a beaker in sequence and mixed evenly with magnetic stirring at 900 rpm at room temperature to complete the one-step synthesis of superhydrophobic water solution.

[0055] The surface to be treated requires no additional preparation; materials such as glass, fiber fabric, and aluminum alloy can be used. The substrate is immersed in the coating solution for 2 hours. After immersion, the substrate is removed and can be allowed to dry naturally at room temperature or accelerated artificially. The drying temperature is controlled at 50℃, the airflow rate at 20L / s, and the drying time at 0.015 hours to obtain a superhydrophobic multifunctional coating that completely covers the substrate surface. The water contact angle is tested after drying, and then the coating is exposed at room temperature for 168, 336, and 504 hours to analyze its water contact angle, roll-off angle, and stability. The water contact angle is shown in the figure. Figure 6 As shown, the change in the contact angle of the coating on the aluminum substrate over time is shown in the figure. Figure 8 As shown, the change in the roll angle of the coating on the aluminum substrate over time is shown in the figure. Figure 9 As shown.

[0056] Example 7: Preparation of MR-D13B superhydrophobic coating

[0057] A method for preparing a multifunctional superhydrophobic coating on the surface of a target material, wherein the selected substrate does not require surface pretreatment and can be directly coated, and the following materials are accurately weighed according to the formula: 0.1 v / v% polymethylsiloxane (viscosity 300 cst) and 2 v / v% fluorocarbon silane (molecular formula C 11 H 13 F 13 O3Si); ​​1.5 v / v% silica (average particle size ≤5 nm, density 0.05 g / ml); 60 v / v% polysiloxane; 36.4 v / v% decamethylcyclopentasiloxane D5. The above materials were added to a beaker in sequence and mixed evenly with magnetic stirring at 1100 rpm at room temperature. The superhydrophobic water solution was synthesized in one step.

[0058] The surface to be treated requires no additional preparation; materials such as glass, fiber fabric, and aluminum alloy can be used. Immerse the substrate in the coating solution for 1 hour. Then remove the substrate and allow it to air dry at room temperature or accelerate drying artificially. Control the drying temperature (25℃), airflow rate at 40L / s, and drying time at 0.005 hours to obtain a superhydrophobic multifunctional coating that completely covers the substrate surface. The water contact angle is as follows: Figure 7 As shown, the change in the contact angle of the coating on the aluminum substrate over time is shown in the figure. Figure 8 As shown, the change in the roll angle of the coating on the aluminum substrate over time is shown in the figure. Figure 9 As shown.

[0059] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A superhydrophobic multifunctional coating, characterized in that: By volume percentage, it comprises the following components: 0.1–3.0% hydrophobic composition, 1.5–12% texture stabilizer, 17–60% binder, and 25–80% alcohol-free base material; The hydrophobic composition includes fluorocarbon silanes with the molecular formula CxHyF. 13 O3Si, where x is an integer from 10 to 15 and y is an integer from 12 to 20; the hydrophobic composition further includes polymethylsiloxane with a viscosity of 200 to 1000 cst; the texture stabilizer is silica with a specific surface area of ​​70 to 320 m². 2 / g, with an average particle size of ≤5nm; the binder is a polysiloxane, wherein the mass fraction of silicon dioxide is 25-50 wt% and the mass fraction of tetraethoxysilane is 10-70 wt%; the alcohol-free base material is a polymethylcyclosiloxane, wherein the polymethylcyclosiloxane is Dx, and x is an integer from 4 to 5; The superhydrophobic multifunctional coating has a water contact angle ≥160±5° and a roll-off angle ≤5°.

2. A method for preparing the superhydrophobic multifunctional coating according to claim 1, characterized in that: The hydrophobic composition, texture stabilizer, binder and alcohol-free base material are stirred and mixed evenly to synthesize a superhydrophobic coating solution; the substrate is immersed in the prepared superhydrophobic coating solution for 1 to 36 hours, and then the immersed substrate is taken out and dried by blowing at a temperature of 17 to 100°C and an air flow rate of 10 to 40 L / s to obtain a superhydrophobic multifunctional coating.

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