Super-hydrophobic anti-icing coating and preparation method thereof

Abstract

The invention discloses a super-hydrophobic anti-icing coating and a preparation method thereof, and relates to the technical field of hydrophobic coatings, the method comprises the following steps: flattening and fixing a lotus leaf, then mixing PDMS A and B glue, pouring on the lotus leaf, removing bubbles, heating and curing to obtain a PDMS template with a lotus leaf surface mastoid structure; spraying the ZIF-8 nano-particle dispersion liquid onto a PDMS (Polydimethylsiloxane) template; the preparation method comprises the following steps: uniformly mixing epoxy resin and a curing agent, removing bubbles, uniformly smearing on a base material, heating and curing to be half-dry, putting a PDMS template on the epoxy resin coating, curing at room temperature, and removing the PDMS template to obtain the super-hydrophobic anti-icing coating. The invention also discloses the super-hydrophobic anti-icing coating prepared by the method. According to the method, the hydrophobic structure on the surface of the lotus leaf is copied to the surface of the material through a template etching method, the hydrophobic and anti-icing performance of the coating is greatly improved, corrosion and damage of the material are reduced, and the method has high application value.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrophobic coatings, and in particular to a super hydrophobic anti-icing coating and a preparation method thereof. Background Art

[0002] Material corrosion is an irreversible natural phenomenon. The corrosion problem of materials has become a major problem threatening the development of the world's industry. Improving the corrosion resistance of materials is urgent. Traditional deicing methods, such as heating, salting and snow-melting agents, often consume a lot of energy or cause serious pollution to the soil, water sources and vegetation. Superhydrophobic coatings are favored by many researchers due to their super hydrophobic properties on the surface, and provide innovative ideas for the research on anti-icing and anti-corrosion of material surfaces.

[0003] Super-hydrophobic anti-icing coatings can reduce the adhesion of ice to the surface of objects, making it easier for ice to fall off naturally or be removed with less external force. This reduces reliance on energy-intensive de-icing methods, thereby reducing energy consumption, greenhouse gas emissions and negative impacts on the environment caused by energy production. In addition, hydrophobic anti-icing coatings prevent the formation and adhesion of ice through physical action, without the risk of chemical contamination.

[0004] In recent years, due to the very unstable hierarchical roughness structure and low surface energy components on the surface of super-hydrophobic materials, usually, under the action of slight shear force, the hierarchical roughness structure and low surface energy components are easily destroyed, causing the material to lose its super-hydrophobicity, reducing the service life of the material and reducing the use value of the material. This has become the most prominent problem hindering the practical application of super-hydrophobic materials and needs to be solved urgently. Although some researchers have proposed methods such as adding an adhesive layer and adding a repair agent to extend the service life of super-hydrophobic materials, these studies have only stayed at the two-dimensional level and have certain limitations in thinking. Therefore, the existing problems have not yet been well solved. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a super hydrophobic anti-icing coating and a preparation method thereof. The method replicates the hydrophobic structure of the lotus leaf surface to the material surface through a template etching method, which greatly improves the hydrophobic and anti-icing properties of the coating, helps to reduce corrosion and damage of the material, and has great application value.

[0006] The technical solution of the present invention to solve the above technical problems is as follows: a method for preparing a super-hydrophobic anti-icing coating is provided, comprising the following steps:

[0007] (1) The lotus leaf is flattened and fixed, and then PDMS glue A and PDMS glue B are mixed evenly and poured on the lotus leaf, and bubbles are removed by vacuum degassing, and the mixture is cured at room temperature, and finally peeled off from the lotus leaf to obtain a PDMS template with a lotus leaf surface papillary structure;

[0008] (2) Dispersing ZIF-8 nanoparticles in ethyl acetate and then spraying them evenly onto the side of the PDMS template with the papillary structure;

[0009] (3) The epoxy resin and the curing agent are mixed evenly, and bubbles are removed by vacuum degassing. Then, the epoxy resin and the curing agent are evenly applied on the substrate, and heated and cured until semi-dry. Then, the PDMS template treated in step (2) is placed on the epoxy resin coating, and the side with the papillary structure is close to the epoxy resin coating. Finally, the epoxy resin coating is cured at room temperature, and the PDMS template is removed to obtain a super hydrophobic anti-icing coating.

[0010] Furthermore, in step (1), the volume ratio of PDMS A glue to PDMS B glue is 1:0.8-1.2, wherein PDMS A glue is a PDMS prepolymer and PDMS B glue is a curing agent.

[0011] Furthermore, in step (1), curing is carried out at room temperature for 12-24 hours.

[0012] Furthermore, in step (2), ZIF-8 nanoparticles are prepared by the following method: zinc nitrate, 2-methylimidazole and water are mixed evenly, allowed to react for 24 hours, and then centrifuged, washed and dried to obtain ZIF-8 nanoparticles.

[0013] Furthermore, in step (2), the mass ratio of ZIF-8 nanoparticles to ethyl acetate is 0.6-1.4:1.

[0014] Furthermore, in step (3), the mass ratio of epoxy resin to curing agent is 2-4:1.

[0015] Furthermore, in step (3), the curing agent is polyetheramine D230.

[0016] Furthermore, in step (3), the coating thickness is 0.8-1.2 mm; and the substrate is a carbon fiber sheet.

[0017] Furthermore, in step (3), the mixture is heated to 45-80° C. and cured for 10-45 minutes until semi-dry; and cured at room temperature for 20-30 hours.

[0018] The method of the present invention first allows PDMS (polydimethylsiloxane) to solidify on the surface of the lotus leaf, and the papillary structure on the surface of the lotus leaf is traced down as a template; then the ZIF-8 nanoparticle dispersion is evenly sprayed on the PDMS template, so that the super-hydrophobic ZIF-8 nanoparticles are embedded in the papillary structure of the PDMS template; then the PDMS template is placed on the epoxy resin coating, the epoxy resin is cured, and the lotus leaf papillary structure and the super-hydrophobic ZIF-8 nanoparticles on the PDMS template are copied to the epoxy resin to obtain a super-hydrophobic anti-icing coating. The super-hydrophobic coating is a coating composed of a mixed solution of epoxy resin and polyetheramine D230, ZIF-8 nanoparticles and the papillary structure.

[0019] The present invention also provides a super-hydrophobic anti-icing coating prepared by the preparation method of the super-hydrophobic anti-icing coating.

[0020] The present invention has the following beneficial effects:

[0021] 1. The method of the present invention adopts a template etching method to skillfully etch the hydrophobic structure on the surface of the lotus leaf, and sprays a super-hydrophobic coating ZIF-8 to further prepare a coating with a super-hydrophobic composite surface, so that the surface of the material has a super-hydrophobic and anti-icing effect.

[0022] 2. The water contact angle of the super-hydrophobic anti-icing coating prepared by the method of the present invention is significantly increased, and the freezing time is also prolonged. After freezing, the ice layer mainly exists in the form of frost ice with a loose structure. The frost ice with this structure has a weak bonding force with the base material and is easily carried away by wind at a certain wind speed. The greater the wind speed, the more conducive it is to the occurrence of ice shedding, thereby having a beneficial effect on reducing the weight of the sample.

[0023] 3. The present invention forms a microscopic or nano-scale structure on the surface so that water droplets form a high contact angle when contacting the surface, thereby achieving the effect of rapid rolling of water droplets and difficulty in forming ice crystals on the surface, thereby achieving the purpose of super-hydrophobic anti-icing. The research and development of the present invention not only helps to improve the performance of drones in low temperature and high humidity environments, but also reduces the additional energy consumption and maintenance costs caused by icing. It can not only significantly improve the performance of drones in harsh climatic conditions, but also provide new ideas for the design and maintenance of drones. The advancement of this technology also provides reference for anti-icing research in other fields, including aerospace, ocean exploration, and transportation, showing its cross-field application prospects.

[0024] 4. The super-hydrophobic anti-icing coating of the present invention can make the surface of the substrate have a waterproof and anti-icing effect, thereby reducing corrosion and damage, extending the service life of infrastructure, and reducing maintenance frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of fixing a lotus leaf in Example 1;

[0026] Figure 2 This is a schematic diagram of the PDMS template in Example 1;

[0027] Figure 3 This is a schematic diagram of the operation of step (3) in Example 1;

[0028] Figure 4 This is a schematic diagram of the structure of the super hydrophobic anti-icing coating prepared in Example 1;

[0029] Figure 5 Schematic diagram of the coating structure obtained in Comparative Example 1;

[0030] Figure 6 This is an electron microscope image of the super hydrophobic anti-icing coating prepared in Example 1;

[0031] Figure 7 The electron microscope images of the coatings prepared in Example 1 and Comparative Example 1;

[0032] Figure 8 The surface energy spectrum of the super hydrophobic anti-icing coating prepared in Example 1;

[0033] Fig. 9 This is a contact angle test result diagram of the super hydrophobic anti-icing coating prepared in Example 1;

[0034] Fig.10 The contact angle test result diagram of the coating prepared in Comparative Example 1;

[0035] Fig.11 This is a comparison chart of the freezing of the original plate and the super-hydrophobic anti-icing coating prepared in Example 1. DETAILED DESCRIPTION

[0036] The principles and features of the present invention are described below, and the examples are only used to explain the present invention and are not used to limit the scope of the present invention. If no specific conditions are specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0037] Example 1

[0038] A super hydrophobic anti-icing coating, the preparation method of which comprises the following steps:

[0039] (1) Figure 1 As shown in the figure, the lotus leaf is flattened and fixed, and then PDMS A glue and PDMS B glue are mixed evenly in a volume ratio of 1:1 and poured on the lotus leaf. The bubbles are removed by vacuum degassing, and the mixture is cured at room temperature for 20 hours. Finally, the mixture is peeled off from the lotus leaf to obtain a PDMS template with a lotus leaf surface papillary structure (as shown in the figure). Figure 2 shown);

[0040] (2) Dispersing ZIF-8 nanoparticles in ethyl acetate at a mass ratio of 1:1, and then spraying them evenly onto the side of the PDMS template with the papillary structure;

[0041] (3) Epoxy resin and polyetheramine D230 were mixed in a mass ratio of 3:1, and bubbles were removed by vacuum degassing. Then, the mixture was evenly applied on the substrate (carbon fiber sheet) with a thickness of 1 mm. The mixture was heated to 60°C and cured for 30 min until semi-dry. Then, the PDMS template treated in step (2) was placed on the epoxy resin coating (such as Figure 3 As shown), and the side with the papillary structure is placed close to the epoxy resin coating, and finally cured at room temperature for 24 hours, the PDMS template is removed to obtain a super hydrophobic anti-icing coating (as shown Figure 4 shown).

[0042] Example 2

[0043] A super hydrophobic anti-icing coating, the preparation method of which comprises the following steps:

[0044] (1) The lotus leaf is flattened and fixed, and then PDMS glue A and PDMS glue B are mixed evenly in a volume ratio of 1:0.8 and poured on the lotus leaf. The bubbles are removed by vacuum degassing, and the mixture is cured at room temperature for 12 h. Finally, the mixture is peeled off from the lotus leaf to obtain a PDMS template with a lotus leaf surface papillary structure.

[0045] (2) Dispersing ZIF-8 nanoparticles in ethyl acetate at a mass ratio of 0.6:1, and then spraying them evenly onto the side of the PDMS template with the papillary structure;

[0046] (3) Epoxy resin and polyetheramine D230 were mixed in a mass ratio of 2:1, and bubbles were removed by vacuum degassing. Then, the mixture was evenly applied on the substrate (carbon fiber sheet) with a coating thickness of 0.8 mm. The mixture was heated to 45° C. and cured for 45 min until semi-dry. Then, the PDMS template treated in step (2) was placed on the epoxy resin coating, and the side with the papillary structure was placed close to the epoxy resin coating. Finally, the mixture was cured at room temperature for 20 h, and the PDMS template was removed to obtain a superhydrophobic anti-icing coating.

[0047] Example 3

[0048] A super hydrophobic anti-icing coating, the preparation method of which comprises the following steps:

[0049] (1) The lotus leaf is flattened and fixed, and then PDMS A glue and PDMS B glue are mixed evenly in a volume ratio of 1:1.2 and poured on the lotus leaf. The bubbles are removed by vacuum degassing, and the mixture is cured at room temperature for 24 hours. Finally, the mixture is peeled off from the lotus leaf to obtain a PDMS template with a lotus leaf surface papillary structure.

[0050] (2) Dispersing ZIF-8 nanoparticles in ethyl acetate at a mass ratio of 1.4:1, and then spraying them evenly onto the side of the PDMS template with the papillary structure;

[0051] (3) Epoxy resin and polyetheramine D230 were mixed in a mass ratio of 4:1, and bubbles were removed by vacuum degassing. Then, the mixture was evenly applied on the substrate (carbon fiber sheet) with a coating thickness of 1.2 mm. The mixture was heated to 80° C. and cured for 10 min until semi-dry. Then, the PDMS template treated in step (2) was placed on the epoxy resin coating, and the side with the papillary structure was placed close to the epoxy resin coating. Finally, the mixture was cured at room temperature for 30 h, and the PDMS template was removed to obtain a superhydrophobic anti-icing coating.

[0052] Comparative Example 1

[0053] A coating, the preparation method of which comprises the following steps:

[0054] (1) PDMS A glue and PDMS B glue were mixed in a volume ratio of 1:1 and poured into the mold, and bubbles were removed by vacuum degassing. The mixture was cured at room temperature for 20 h to obtain a PDMS template.

[0055] (2) Dispersing ZIF-8 nanoparticles in ethyl acetate at a mass ratio of 1:1, and then spraying them evenly onto the PDMS template;

[0056] (3) Epoxy resin and polyetheramine D230 were mixed in a mass ratio of 3:1, and bubbles were removed by vacuum degassing. Then, the epoxy resin was evenly applied on the substrate (carbon fiber sheet) with a coating thickness of 1 mm. The mixture was heated to 60°C and cured for 30 min until semi-dry. Then, the PDMS template treated in step (2) was placed on the epoxy resin coating, and the side with ZIF-8 nanoparticles was placed close to the epoxy resin coating. Finally, the mixture was cured at room temperature for 24 h, and the PDMS template was removed to obtain a coating (such as Figure 5 shown).

[0057] Test Example 1

[0058] (1) The coatings obtained in Example 1 and Comparative Example 1 are shown in electron microscope images. Figure 6 and Figure 7 The results show that the super-hydrophobic anti-icing coating prepared by the method of the present invention has a papillary structure similar to the surface of a lotus leaf.

[0059] (2) The surface energy spectrum of the super hydrophobic anti-icing coating prepared in Example 1 is as follows Figure 8 The results show that C, O, and Zn elements are evenly distributed, indicating that ZIF-8 nanoparticles are successfully transferred to the surface of the epoxy coating and are evenly distributed.

[0060] (3) The contact angle test results of the coatings prepared in Example 1 and Comparative Example 1 are as follows: Fig. 9 and Fig.10 The results show that the water contact angle of the coating prepared in Example 1 (158°) is significantly greater than that of Comparative Example 1 (111°), indicating that the papillary structure on the surface of the superhydrophobic anti-icing coating is beneficial to the hydrophobic property of the coating.

[0061] (4) The carbon fiber sheet as is and the super-hydrophobic anti-icing coating prepared in Example 1 were placed on a cold platform for an icing experiment. The results are as follows: Fig.11 The results show that under the condition of -10℃, the freezing time of the original plate is 107s, and the freezing time of the coating of Example 1 reaches 3552s, which is extended by 3659s. In addition, the ice layer on the surface of the coating of Example 1 is mainly in the form of frost ice with loose structure. The frost ice of this structure has weak bonding force with the base material and is easier to fall off.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a super hydrophobic anti-icing coating, characterized in that: The following steps are involved: (1) The lotus leaf is flattened and fixed, and then PDMS glue A and PDMS glue B are mixed evenly and poured on the lotus leaf, and bubbles are removed by vacuum degassing, and the mixture is cured at room temperature, and finally peeled off from the lotus leaf to obtain a PDMS template with a lotus leaf surface papillary structure; (2) Dispersing ZIF-8 nanoparticles in ethyl acetate and then spraying them evenly onto the side of the PDMS template with the papillary structure; (3) The epoxy resin and the curing agent are mixed evenly, and bubbles are removed by vacuum degassing. Then, the epoxy resin and the curing agent are evenly applied on the substrate, and heated and cured until semi-dry. Then, the PDMS template treated in step (2) is placed on the epoxy resin coating, and the side with the papillary structure is close to the epoxy resin coating. Finally, the epoxy resin coating is cured at room temperature, and the PDMS template is removed to obtain a super hydrophobic anti-icing coating.

2. The method for preparing a super hydrophobic anti-icing coating according to claim 1, wherein: In step (1), the volume ratio of the PDMSA glue to the PDMS B glue is 1:0.8-1.

2.

3. The method for preparing a super hydrophobic anti-icing coating according to claim 1, characterized in that: In step (2), the ZIF-8 nanoparticles are prepared by the following method: zinc nitrate, 2-methylimidazole and water are mixed evenly, allowed to react for 24 hours, and then centrifuged, washed and dried to obtain ZIF-8 nanoparticles.

4. The method for preparing a super hydrophobic anti-icing coating according to claim 1, wherein: In step (2), the mass ratio of the ZIF-8 nanoparticles to ethyl acetate is 0.6-1.4:

1.

5. The method for preparing a super hydrophobic anti-icing coating according to claim 1, characterized in that: In step (3), the mass ratio of the epoxy resin to the curing agent is 2-4:

1.

6. The method for preparing a super hydrophobic anti-icing coating according to claim 1, characterized in that: In step (3), the curing agent is polyetheramine D230.

7. The method for preparing a super hydrophobic anti-icing coating according to claim 1, characterized in that: In step (3), the coating thickness is 0.8-1.2 mm.

8. The method for preparing a super hydrophobic anti-icing coating according to claim 1, characterized in that: In step (3), the substrate is a carbon fiber sheet.

9. The method for preparing a super hydrophobic anti-icing coating according to claim 1, wherein: In step (3), heat to 45-80°C and cure for 10-45 minutes until semi-dry; and cure at room temperature for 20-30 hours.

10. A super-hydrophobic anti-icing coating prepared by the method for preparing a super-hydrophobic anti-icing coating according to any one of claims 1 to 9.

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