A super-hydrophobic anti-icing coating and a method of making the same

Abstract

The application relates to the technical field of super-hydrophobic coating, in particular to a super-hydrophobic anti-icing coating and a preparation method thereof; the method comprises the following steps: dispersing hydrophobic SiO2 nanoparticles in a polyurethane solution to obtain a dispersion liquid; mixing polydimethylsiloxane and a curing agent, and then adding the mixture into the dispersion liquid to perform first dispersion treatment, so as to obtain a first mixed liquid; adding polyurethane resin into the first mixed liquid to perform second dispersion treatment, so as to obtain a second mixed liquid; coating the second mixed liquid on a substrate, and performing curing treatment, so as to obtain the super-hydrophobic anti-icing coating. The prepared super-hydrophobic anti-icing coating not only has excellent hydrophobicity and wear resistance, but also has good chemical stability.

Description

Technical Field

[0001] This invention relates to the field of superhydrophobic coating technology, and more specifically, to a superhydrophobic anti-icing coating and its preparation method. Background Technology

[0002] In recent years, a large number of wind farms have expanded to high-altitude, low-temperature areas. Consequently, wind turbines are prone to icing in these cold and humid environments. Icing reduces the power output of wind turbines and affects their structural safety. Existing de-icing methods, including mechanical, manual, and ultrasonic de-icing, suffer from high costs and energy consumption. Applying a hydrophobic coating to the surface of the wind turbine structure holds promise for solving these problems. Besides excellent hydrophobic properties to ensure anti-icing performance, the anti-icing coating also needs good abrasion resistance to ensure its service life. However, existing hydrophobic coatings struggle to simultaneously possess both excellent hydrophobicity and abrasion resistance. Furthermore, the preparation process for existing hydrophobic coatings is complex and costly. Summary of the Invention

[0003] The technical problem solved by this invention is at least one of the following: existing hydrophobic coatings are difficult to simultaneously possess both good hydrophobic properties and good wear resistance; existing hydrophobic coatings have complex preparation processes and high preparation costs.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] A method for preparing a superhydrophobic anti-icing coating, comprising:

[0006] Step S1: Disperse hydrophobic SiO2 nanoparticles in a polyurethane solution to obtain a dispersion;

[0007] Step S2: After mixing polydimethylsiloxane (PDMS) with the curing agent, add the mixture to the dispersion for the first dispersion treatment to obtain the first mixture.

[0008] Step S3: Add polyurethane resin to the first mixture and perform a second dispersion treatment to obtain a second mixture;

[0009] Step S4: Apply the second mixture to the substrate and cure it to obtain a superhydrophobic anti-icing coating.

[0010] Preferably, in step S1, dispersing the hydrophobic SiO2 nanoparticles in a polyurethane solution to obtain a dispersion comprises: dispersing the hydrophobic SiO2 nanoparticles with a mass of m in a polyurethane solution with a volume of v to obtain the dispersion; wherein the ratio of m to v is (0.6-1):(15-25) g / ml.

[0011] Preferably, in step S3, the mass ratio of the hydrophobic SiO2 nanoparticles, the polydimethylsiloxane, the curing agent, and the polyurethane resin in the second mixture is (0.6-1):1:0.1:(0.6-0.8).

[0012] Preferably, in step S4, the curing temperature is 50-100℃ and the time is 1-2 hours.

[0013] Preferably, in step S2, the first dispersion treatment includes ultrasonic dispersion for 30-50 minutes and magnetic stirring for 30-50 minutes.

[0014] Preferably, in step S3, the second dispersion treatment includes ultrasonic dispersion for 10-20 min and magnetic stirring for 10-20 min.

[0015] Preferably, in step S2, the polydimethylsiloxane comprises silicone rubber of model SYLGARD184 manufactured by Dow Corning Incorporated.

[0016] Preferably, in step S4, the substrate includes either a fiberglass sheet or a fiberglass airfoil.

[0017] Preferably, in step S4, the thickness of the superhydrophobic anti-icing coating is 150-250 nm.

[0018] The present invention also provides a superhydrophobic anti-icing coating, which is prepared by the superhydrophobic anti-icing coating preparation method described above.

[0019] Compared with existing technologies, the superhydrophobic anti-icing coating prepared by this invention uses polyurethane as a matrix system and incorporates hydrophobic SiO2 nanoparticles, thereby giving the coating superior hydrophobic properties. Furthermore, the hydrophobic SiO2 nanoparticles have a large specific surface area, and their interaction with the polyurethane, which serves as the framework material, constructs a rough surface structure for the coating, which is beneficial for improving the coating's strength, wear resistance, and hydrophobicity. PDMS has a low surface energy; its introduction into the coating results in a lower surface energy, further enhancing the coating's hydrophobicity. The introduction of polyurethane resin further enhances the coating's chemical stability and wear resistance. Additionally, after being applied to a substrate, this superhydrophobic anti-icing coating effectively reduces the adhesion strength of ice layers on the substrate, facilitating ice removal. In summary, the superhydrophobic anti-icing coating prepared by this invention not only possesses excellent hydrophobicity and wear resistance but also exhibits good chemical stability. Moreover, the preparation method of the superhydrophobic anti-icing coating of this invention has the advantages of simple process, low pollution, and low cost. Attached Figure Description

[0020] Figure 1This is a schematic flowchart of the preparation method of the superhydrophobic anti-icing coating in an embodiment of the present invention;

[0021] Figure 2 This is a test diagram of the contact angle between the fiberglass sheet and the water droplet in Example 3;

[0022] Figure 3 The contact angle test diagram of the fiberglass sheet with superhydrophobic anti-icing coating prepared in Example 3 and water droplets;

[0023] Figure 4 The diagram shows the icing conditions of the fiberglass airfoil in Example 1 and the fiberglass airfoil with superhydrophobic anti-icing coating prepared in Example 1 under conditions of -10℃ and wind speeds of 5m / s, 10m / s, and 15m / s, respectively.

[0024] Figure 5 The graph shows the maximum icing thickness of the fiberglass airfoil (without any coating) in Example 1 and the fiberglass airfoil with superhydrophobic anti-icing coating in Example 1 under different temperatures and wind speeds.

[0025] Figure 6 The graph shows the change in the contact angle between the coating and the water droplet as the number of wear cycles increases in Example 1 and Comparative Example 1.

[0026] Figure 7 This is a statistical chart showing the ice adhesion strength of the fiberglass sheet in Example 3 and the fiberglass sheet with superhydrophobic anti-icing coating prepared in Example 3. Detailed Implementation

[0027] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0028] It should be noted that, unless otherwise specified, the features in the embodiments of this invention can be combined with each other. The terms "comprising," "including," "containing," and "having" are non-limiting, meaning that other steps and other components that do not affect the results can be added. The above terms cover the terms "composed of" and "substantially composed of." Unless otherwise specified, the materials, equipment, and reagents are commercially available.

[0029] like Figure 1 As shown, this embodiment of the invention provides a method for preparing a superhydrophobic anti-icing coating, comprising:

[0030] Step S1: Disperse hydrophobic SiO2 nanoparticles in a polyurethane solution to obtain a dispersion;

[0031] Step S2: After mixing polydimethylsiloxane and curing agent, add the mixture to the dispersion for the first dispersion treatment to obtain the first mixture.

[0032] Step S3: Add polyurethane resin to the first mixture and perform a second dispersion treatment to obtain a second mixture;

[0033] Step S4: Apply the second mixture to the substrate and cure it to obtain a superhydrophobic anti-icing coating.

[0034] Compared with existing technologies, the superhydrophobic anti-icing coating prepared in this invention uses polyurethane as a matrix system and incorporates hydrophobic SiO2 nanoparticles, thereby giving the coating superior hydrophobic properties. Furthermore, the hydrophobic SiO2 nanoparticles have a large specific surface area, and their interaction with the polyurethane, which serves as the framework material, constructs a rough surface structure for the coating, which is beneficial for improving the coating's strength, wear resistance, and hydrophobicity. PDMS has a low surface energy; its introduction into the coating results in a lower surface energy, further enhancing the coating's hydrophobicity. The introduction of polyurethane resin further enhances the coating's chemical stability and wear resistance. Additionally, after being applied to a substrate, this superhydrophobic anti-icing coating effectively reduces the adhesion strength of ice layers on the substrate, facilitating ice removal. In summary, the superhydrophobic anti-icing coating prepared by this invention not only possesses excellent hydrophobicity and wear resistance but also exhibits good chemical stability. Moreover, the preparation method of the superhydrophobic anti-icing coating provided in this invention has the advantages of simple process, low pollution, and low cost.

[0035] In some embodiments of the present invention, step S1, dispersing hydrophobic SiO2 nanoparticles in a polyurethane solution to obtain a dispersion, includes: dispersing the hydrophobic SiO2 nanoparticles with a mass of m in a polyurethane solution with a volume of v to obtain the dispersion; the ratio of m to v is (0.6-1):(15-25) g / ml.

[0036] In some embodiments of the present invention, in step S3, the mass ratio of the hydrophobic SiO2 nanoparticles, the polydimethylsiloxane, the curing agent and the polyurethane resin in the second mixture is (0.6-1):1:0.1:(0.6-0.8).

[0037] In some embodiments of the present invention, in step S4, the curing temperature is 50-100°C and the time is 1-2 hours.

[0038] In some embodiments of the present invention, in step S2, the first dispersion treatment includes ultrasonic dispersion for 30-50 min and magnetic stirring for 30-50 min.

[0039] In some embodiments of the present invention, in step S3, the second dispersion treatment includes ultrasonic dispersion for 10-20 min and magnetic stirring for 10-20 min.

[0040] In some embodiments of the present invention, in step S2, the polydimethylsiloxane comprises silicone rubber of model SYLGARD184 manufactured by Dow Corning Incorporated.

[0041] In some embodiments of the present invention, in step S4, the substrate includes one of fiberglass sheet and fiberglass airfoil.

[0042] In some embodiments of the present invention, in step S4, the thickness of the superhydrophobic anti-icing coating is 150-250 nm.

[0043] The present invention also provides a superhydrophobic anti-icing coating, which is prepared by the superhydrophobic anti-icing coating preparation method described above.

[0044] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0045] It should be noted that in the embodiments and comparative examples of the present invention, the hydrophobic SiO2 nanoparticles used are hydrophobic SiO2 nanoparticles of model R972 produced by Evonik Degussa, the curing agent used is curing agent of model 184 produced by Dow Corning Incorporated, the polydimethylsiloxane used is silicone rubber of model SYLGARD184 produced by Dow Corning Incorporated, and the polyurethane resin used is polyurethane resin of model 685 produced by Zongshi Paint Industry.

[0046] Example 1

[0047] A1. 0.7g of hydrophobic SiO2 nanoparticles were dispersed in 20ml of polyurethane solution to obtain a dispersion; the polyurethane solution was a two-component polyurethane topcoat produced by Anhui Linghu Paint Co., Ltd.

[0048] A2. Mix 1g of polydimethylsiloxane with 0.1g of curing agent, add the mixture to the dispersion, and ultrasonically disperse for 30min and magnetically stir for 30min to obtain the first mixture.

[0049] A3. Add 0.6g of polyurethane resin to the first mixture, ultrasonically disperse for 20min and magnetically stir for 20min to obtain the second mixture;

[0050] A4. The second mixture is coated onto the fiberglass airfoil and cured in an oven to obtain a superhydrophobic anti-icing coating; wherein the thickness of the superhydrophobic anti-icing coating is 150 nm, the curing temperature is 100 °C, and the curing time is 1 h.

[0051] Example 2

[0052] A1. 1g of hydrophobic SiO2 nanoparticles were dispersed in 25ml of polyurethane solution to obtain a dispersion; the polyurethane solution was a two-component polyurethane topcoat produced by Anhui Linghu Paint Co., Ltd.

[0053] A2. Mix 1g of polydimethylsiloxane with 0.1g of curing agent, add the mixture to the dispersion, and ultrasonically disperse for 50min and magnetically stir for 50min to obtain the first mixture.

[0054] A3. Add 0.6g of polyurethane resin to the first mixture, ultrasonically disperse for 10min and magnetically stir for 10min to obtain the second mixture;

[0055] A4. The second mixture is coated onto the fiberglass airfoil and cured in an oven to obtain a superhydrophobic anti-icing coating; wherein the thickness of the superhydrophobic anti-icing coating is 150 nm, the curing temperature is 50 °C, and the curing time is 2 h.

[0056] Example 3

[0057] The difference from Example 1 is that the fiberglass airfoil in step A4 is replaced with a fiberglass sheet.

[0058] Comparative Example 1

[0059] The difference from Example 1 is that the polyurethane solution in step A1 is replaced by an equal volume of ethyl acetate.

[0060] Experimental Example

[0061] The fiberglass sheet (without any coating) from Example 3 and the fiberglass sheet with the superhydrophobic anti-icing coating prepared in Example 3 were subjected to contact angle tests with water droplets, respectively. The results are shown in [Figure 1]. Figure 2 and Figure 3 . Figure 2 The diagram shows the contact angle test between the fiberglass sheet and the water droplet. Figure 3 The image shows the contact angle test results between the fiberglass sheet with the superhydrophobic anti-icing coating prepared in Example 3 and a water droplet. Figure 2 and Figure 3 It can be seen that the contact angle between the fiberglass sheet (without any coating) and the water droplet is only 55.68°, while the contact angle between the fiberglass sheet with the superhydrophobic anti-icing coating prepared in Example 3 and the water droplet is 154.01°. This demonstrates that the superhydrophobic anti-icing coating prepared in Example 3 has better hydrophobic properties. It should be noted that... Figure 2 and Figure 3 CA represents the contact angle.

[0062] The fiberglass airfoil from Example 1 (without any coating) and the fiberglass airfoil with a superhydrophobic anti-icing coating prepared in Example 1 were observed to exhibit icing behavior in a wind tunnel at -10°C and wind speeds of 5 m / s, 10 m / s, and 15 m / s, respectively. The results are shown in the figure. Figure 4 , Figure 4 The diagram shows the icing situation of the fiberglass airfoil without coating in Example 1, and the diagram shows the icing situation of the fiberglass airfoil with superhydrophobic anti-icing coating obtained in Example 1 with composite coating. Specifically, it includes the shape of the fiberglass airfoil and the shape of water freezing on the surface of the fiberglass airfoil. Figure 4 In the middle, X represents the length, from Figure 4 It can be seen that, compared with the fiberglass airfoil in Example 1, the surface icing of the fiberglass airfoil with superhydrophobic anti-icing coating prepared in Example 1 is significantly improved.

[0063] The icing thickness of the fiberglass airfoil (without any coating) from Example 1 and the fiberglass airfoil with a superhydrophobic anti-icing coating from Example 1 were statistically analyzed in a wind tunnel under wind speeds of 5 m / s, 10 m / s, and 15 m / s at -10°C and 5 m / s, 10 m / s, and 15 m / s at -15°C, respectively. The results are shown in […]. Figure 5 , Figure 5 The six groups of bars distributed from left to right along the horizontal axis correspond to the following experimental conditions: temperature -10℃, wind speed 5m / s; temperature -10℃, wind speed 10m / s; temperature -10℃, wind speed 15m / s; temperature -15℃, wind speed 5m / s; temperature -15℃, wind speed 10m / s; and temperature -15℃, wind speed 15m / s. Figure 5 As can be seen, compared with the fiberglass airfoil in Example 1, the maximum surface icing thickness of the fiberglass airfoil with superhydrophobic anti-icing coating prepared in Example 1 is reduced. Figure 5 The maximum icing thickness of the fiberglass airfoil without coating corresponds to that in Example 1, while the maximum icing thickness of the fiberglass airfoil with superhydrophobic anti-icing coating obtained in Example 1 corresponds to that in Example 1.

[0064] The coatings prepared in Example 1 and Comparative Example 1 were abraded using 240-grit sandpaper. The changes in the contact angle between the coating and water droplets were observed with the number of abrasion cycles. The results are shown in […]. Figure 6 ,from Figure 6 As can be seen, with the increase of the number of wear cycles, the contact angle between the coating and the water droplet prepared in Example 1 is basically maintained at about 150°, and the contact angle between the coating and the water droplet does not change much; with the increase of the number of wear cycles, the contact angle between the coating and the water droplet prepared in Comparative Example 1 changes more significantly and shows a gradually decreasing trend; it can be seen that, compared with Comparative Example 1, the coating prepared in Example 1 has better wear resistance. Figure 6 The horizontal axis represents the number of wear cycles, and the vertical axis represents the contact angle.

[0065] The ice adhesion strength of the fiberglass sheet (without any coating) in Example 3 and the fiberglass sheet with a superhydrophobic anti-icing coating prepared in Example 3 after icing at -10℃ and a wind speed of 10m / s was tested. The test results are shown in [Figure 1]. Figure 7 ,from Figure 7 As can be seen, the ice adhesion strength of the fiberglass sheet (without any coating) in Example 3 is 134.98 kPa, while the ice adhesion strength of the fiberglass sheet with the superhydrophobic anti-icing coating prepared in Example 3 is 68.77 kPa. This shows that the fiberglass sheet with the superhydrophobic anti-icing coating prepared in Example 3 has a lower ice adhesion strength, which is more conducive to ice removal. This is because the superhydrophobic anti-icing coating on the surface of the fiberglass sheet is in a Cassie state during the icing process. The rough surface of the coating results in a smaller actual contact area between the ice layer and the superhydrophobic anti-icing coating. It should be noted that... Figure 7 The uncoated fiberglass sheet corresponds to the ice adhesion strength of the fiberglass sheet in Example 3, while the composite coating corresponds to the ice adhesion strength of the fiberglass sheet with the superhydrophobic anti-icing coating prepared in Example 3.

[0066] It should be noted that the Cassie state is a physical state describing a solid surface, involving the interaction between a liquid and a solid. In this state, the liquid and solid are not in complete contact, and there is usually a gas between them; this gas region is called an "air cushion" or "air chamber".

[0067] Furthermore, it should be noted that although the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for preparing a superhydrophobic anti-icing coating, characterized in that, include: Step S1: Disperse hydrophobic SiO2 nanoparticles in a polyurethane solution to obtain a dispersion; The process of dispersing hydrophobic SiO2 nanoparticles in a polyurethane solution to obtain a dispersion comprises: dispersing the hydrophobic SiO2 nanoparticles with a mass of m in a polyurethane solution with a volume of v to obtain the dispersion; the ratio of m to v is (0.6-1):(15-25) g / ml; the polyurethane solution is a two-component polyurethane topcoat produced by Anhui Linghu Paint Co., Ltd. Step S2: After mixing polydimethylsiloxane and curing agent, add the mixture to the dispersion for the first dispersion treatment to obtain the first mixture. Step S3: Add polyurethane resin to the first mixture and perform a second dispersion treatment to obtain a second mixture; the mass ratio of the hydrophobic SiO2 nanoparticles, the polydimethylsiloxane, the curing agent and the polyurethane resin in the second mixture is (0.6-1):1:0.1:(0.6-0.8). Step S4: Apply the second mixture to the substrate and cure it to obtain a superhydrophobic anti-icing coating.

2. The method for preparing the superhydrophobic anti-icing coating according to claim 1, characterized in that, In step S4, the curing temperature is 50-100℃ and the time is 1-2 hours.

3. The method for preparing the superhydrophobic anti-icing coating according to claim 1, characterized in that, In step S2, the first dispersion treatment includes ultrasonic dispersion for 30-50 minutes and magnetic stirring for 30-50 minutes.

4. The method for preparing the superhydrophobic anti-icing coating according to claim 1, characterized in that, In step S3, the second dispersion treatment includes ultrasonic dispersion for 10-20 minutes and magnetic stirring for 10-20 minutes.

5. The method for preparing the superhydrophobic anti-icing coating according to claim 1, characterized in that, In step S2, the polydimethylsiloxane includes silicone rubber of model SYLGARD184 manufactured by Dow Corning Incorporated.

6. The method for preparing the superhydrophobic anti-icing coating according to claim 1, characterized in that, In step S4, the substrate includes either fiberglass sheet or fiberglass airfoil.

7. The method for preparing the superhydrophobic anti-icing coating according to claim 1, characterized in that, In step S4, the thickness of the superhydrophobic anti-icing coating is 150-250 nm.

8. A superhydrophobic anti-icing coating, characterized in that, The superhydrophobic anti-icing coating was prepared using the method described in any one of claims 1-7.

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