A functional super-hydrophobic shape memory coating and preparation method thereof

Abstract

The present invention provides a functional super-hydrophobic shape memory coating and a preparation method thereof, relating to the technical field of super-hydrophobic coatings. The specific preparation method is as follows: a substrate material is sandblasted; a coating is applied on a substrate material and heated and cured to obtain an initial coating; the initial coating is photolithographically processed to obtain a coating with an array structure; a silane compound is deposited on the surface of the coating with an array structure to obtain a functional super-hydrophobic shape memory coating; wherein the coating is prepared from a film-forming substance, a curing agent and a hydrophobic inorganic nanomaterial. The micro-nanostructure of the coating surface obtained by the above method is destroyed by an external mechanical force, and can be restored by heating, powering on, infrared light irradiation, etc., so that it regains hydrophobicity, effectively solving the problem of poor stability and durability of existing super-hydrophobic coatings.

Description

Technical Field

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

[0002] Superhydrophobic coating refers to a special surface with a static contact angle (CA) of water droplets on the coating surface greater than 150° and a rolling angle (SA) less than 10°. Superhydrophobic coatings are widely used in the fields of corrosion protection, anti-icing, oil-water separation, self-cleaning, etc. due to their special superhydrophobicity, making them have broad application prospects in the production and life of military equipment and civilian facilities. However, there are still some shortcomings of superhydrophobic surfaces that need to be solved: (1) Due to the poor adhesion between the coating and the substrate, and the micro-nanostructure on the surface of the material is easily destroyed by impact, the stability and durability of the superhydrophobic surface are poor; (2) When there is water vapor on the surface of the superhydrophobic coating, when the temperature suddenly drops below the dew point, the water vapor will condense in the micro-nanostructure on the surface of the coating, causing the coating to lose its superhydrophobicity; (3) When oil or emulsifiers are present, the surface tension of water will be greatly reduced, causing the coating to lose its superhydrophobicity. The shortcomings of superhydrophobic surfaces greatly limit their application, and a single superhydrophobicity is difficult to meet the use requirements of materials in harsh environments and emerging fields. Shape memory polymers, a class of stimulus-responsive and self-regulating smart materials, are widely used in aerospace, biomedicine, electronics, smart manufacturing, and other fields. Shape memory polymers can return to their initial, fixed shape from a temporary shape in response to external stimuli (such as heat, magnetism, electricity, light, and solutions). Utilizing the self-regulating properties of shape memory polymers to effectively overcome the shortcomings of existing superhydrophobic coatings and imparting them with diverse functionalities for application in diverse fields is a pressing challenge for those skilled in the art. Summary of the Invention

[0003] The purpose of the present invention is to provide a functional super-hydrophobic shape memory coating and its preparation method and application, so as to solve the problem of poor stability and durability of super-hydrophobic coatings made from existing super-hydrophobic coatings.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a method for preparing a functional super-hydrophobic shape memory coating, comprising the following steps:

[0006] 1) Sandblasting the base material;

[0007] 2) applying the coating on the base material and heating and curing to obtain an initial coating;

[0008] 3) performing photolithographic processing on the initial coating to obtain a coating having an array structure;

[0009] 4) Depositing silane compounds on the surface of the coating with an array structure to obtain a functional superhydrophobic shape memory coating.

[0010] Preferably, the coating comprises the following raw materials in parts by mass: 10 to 25 parts of a film-forming substance, 5 to 10 parts of a curing agent, and 0.5 to 5 parts of a hydrophobic inorganic nanomaterial;

[0011] The mass ratio of the film-forming substance to the hydrophobic inorganic nanomaterial is 10:0.5-2.

[0012] Preferably, the film-forming substance comprises one or more of epoxy resin, polyester and polyimide.

[0013] Preferably, the curing agent is a hydroxyalkylamide or a mixture of n-octylamine and m-xylidine;

[0014] The molar ratio of n-octylamine to m-xylidine is 1-3:1.

[0015] Preferably, the hydrophobic inorganic nanomaterial is an inorganic nanomaterial that has been modified to have low surface energy.

[0016] Preferably, the preparation method of the hydrophobic inorganic nanomaterial is as follows:

[0017] 1) dispersing inorganic nanoparticles and a low surface energy modifier in ethanol to obtain a dispersion;

[0018] 2) subjecting the dispersion to a hydrothermal reaction to obtain a hydrophobic inorganic nanomaterial.

[0019] Preferably, the temperature of the hydrothermal reaction is 80-200° C., and the time of the hydrothermal reaction is 8-48 hours.

[0020] Preferably, the inorganic nanomaterial comprises one or more of carbon nanotubes, nano-Fe3O4, nano-ZnFe2O4 and nanozyme Ni-V metal oxide;

[0021] Preferably, the particle size of the inorganic nanomaterial is 10 to 500 nm;

[0022] Preferably, the low surface energy modifier comprises one or more of 1H,1H,2H,2H-perfluorodecyltriethoxysilane, trimethylchlorosilane, hexamethyldisilazane and dodecyltrimethoxysilane.

[0023] Preferably, the coating is prepared by reacting hydrophobic inorganic nanoparticles with a film-forming substance to obtain a blend, and then mixing the blend with a curing agent to obtain the coating;

[0024] Preferably, the reaction temperature is 50-100° C., and the reaction time is 20-120 min.

[0025] Preferably, the pitch of the array structure is 1 to 30 μm, and the height of the array structure is 50 to 100 μm.

[0026] Preferably, the method of depositing the silane compound on the surface of the coating with the array structure is to immerse the coating with the array structure in a silane compound solution, remove it, and then dry it.

[0027] Preferably, the mass concentration of the silane compound solution is 0.5-5%, the soaking time is 8-48 hours, and the drying time is 2-24 hours.

[0028] Preferably, the silane compound comprises one or more of 1H,1H,2H,2H-perfluorodecyltriethoxysilane, trimethylchlorosilane, hexamethyldisilazane and dodecyltrimethoxysilane.

[0029] The present invention also provides a functional super-hydrophobic shape memory coating prepared by the above preparation method.

[0030] The present invention has at least the following beneficial effects:

[0031] (1) The super-hydrophobic coating obtained by the present invention is a uniform array, and the coating can be made uniform or anisotropic by giving the coating an array arrangement mode. The coating surface is operable, so that the coating can also be used in fields such as droplet operation.

[0032] (2) The present invention not only prepares a super-hydrophobic coating, but also gives the super-hydrophobic coating wave-absorbing and antibacterial properties, so that the coating can be better applied in the fields of self-image and anti-fouling.

[0033] (3) After the coating obtained by the present invention is damaged by external mechanical force, its super-hydrophobicity can be restored not only by heating, but also by accurately repairing the damaged parts by infrared light, and the coating can also be restored to super-hydrophobicity by electrification. The diversification of repair methods means that the coating is no longer limited to thermal field repair, and can also be accurately repaired by electric field and light, which greatly improves the application range of the coating. DETAILED DESCRIPTION

[0034] The present invention provides a method for preparing a functional super-hydrophobic shape memory coating, comprising the following steps:

[0035] 1) Sandblasting the base material;

[0036] 2) applying the coating on the base material and heating and curing to obtain an initial coating;

[0037] 3) performing photolithographic processing on the initial coating to obtain a coating having an array structure;

[0038] 4) Depositing silane compounds on the surface of the coating with an array structure to obtain a functional superhydrophobic shape memory coating.

[0039] In the present invention, the pressure of the sandblasting treatment in step 1) is preferably 0.7-0.9 MPa, more preferably 0.75-0.85 MPa, and more preferably 0.8 MPa; the angle of the sandblasting treatment is preferably 40-60°, more preferably 45-55°, and more preferably 50°.

[0040] In the present invention, the thickness of the coating applied on the base material in step 2) is preferably 120 to 200 μm, more preferably 130 to 180 μm, and even more preferably 150 to 160 μm.

[0041] In the present invention, the heat curing in step 2) is preferably performed by first heat curing at 50-90°C for 1-3 hours, and then heat curing at 100-140°C for 0.5-2 hours, more preferably first heat curing at 60-80°C for 1.5-2.5 hours, and then heat curing at 110-130°C for 1-1.5 hours, and more preferably first heat curing at 60-80°C for 1.5-2.5 hours, and then heat curing at 110-130°C for 1-1.5 hours.

[0042] In the present invention, the coating comprises the following raw materials in parts by mass: 10 to 25 parts of a film-forming substance, 5 to 10 parts of a curing agent, and 0.5 to 5 parts of a hydrophobic inorganic nanomaterial; preferably, 13 to 22 parts of a film-forming substance, 6 to 9 parts of a curing agent, and 1.3 to 2.2 parts of a hydrophobic inorganic nanomaterial; more preferably, 15 to 20 parts of a film-forming substance, 7 to 8 parts of a curing agent, and 1.5 to 2.0 parts of a hydrophobic inorganic nanomaterial; more preferably, 18 parts of a film-forming substance, 8 parts of a curing agent, and 1.8 parts of a hydrophobic inorganic nanomaterial;

[0043] The mass ratio of the film-forming substance to the hydrophobic inorganic nanomaterial is 10:0.5-2, preferably 10:0.6-1.7, more preferably 10:0.7-1.5, further preferably 10:0.9-1.2, and more preferably 10:1.

[0044] In the present invention, the film-forming material comprises one or more of epoxy resin, polyester and polyimide.

[0045] In the present invention, the curing agent is a hydroxyalkylamide or a mixture of n-octylamine and m-xylidine;

[0046] The molar ratio of n-octylamine to m-xylidine is 1 to 3:1, preferably 1.2 to 2.8:1, more preferably 1.5 to 2.5:1, further preferably 1.8 to 2.2:1, and more preferably 2:1.

[0047] In the present invention, the hydrophobic inorganic nanomaterial is an inorganic nanomaterial that has been modified to have low surface energy.

[0048] In the present invention, the preparation method of the hydrophobic inorganic nanomaterial is as follows:

[0049] 1) dispersing inorganic nanoparticles and a low surface energy modifier in ethanol to obtain a dispersion;

[0050] 2) subjecting the dispersion to a hydrothermal reaction to obtain a hydrophobic inorganic nanomaterial.

[0051] In the present invention, the temperature of the hydrothermal reaction is 80-200°C, preferably 100-180°C, more preferably 120-160°C, and more preferably 140-150°C; the time of the hydrothermal reaction is 8-48h, preferably 12-40h, more preferably 15-30h, further preferably 18-25h, and more preferably 20-22h.

[0052] In the present invention, the inorganic nanomaterials include one or more of carbon nanotubes, nano Fe3O4, nano ZnFe2O4 and nano enzyme Ni-V metal oxide.

[0053] In the present invention, the particle size of the inorganic nanomaterial is 10 to 500 nm, preferably 50 to 400 nm, more preferably 100 to 300 nm, and even more preferably 150 to 200 nm.

[0054] In the present invention, the low surface energy modifier comprises one or more of 1H,1H,2H,2H-perfluorodecyltriethoxysilane, trimethylchlorosilane, hexamethyldisilazane and dodecyltrimethoxysilane.

[0055] In the present invention, the mass ratio of the low surface energy modifier to the inorganic nanoparticles is 0.5-3:1-4, preferably 1-2.5:1.5-3, and more preferably 1-2:2-2.5.

[0056] In the present invention, the coating is prepared by reacting hydrophobic inorganic nanoparticles with a film-forming substance to obtain a blend, and then mixing the blend with a curing agent to obtain the coating.

[0057] In the present invention, the reaction temperature is 50-100°C, preferably 60-90°C, more preferably 70-80°C, and more preferably 75°C; the reaction time is 20-120 min, preferably 40-100 min, more preferably 60-80 min, and more preferably 65-75 min.

[0058] In the present invention, the pitch of the array structure is 1 to 30 μm, preferably 5 to 25 μm, more preferably 10 to 20 μm, and more preferably 10 to 15 μm; the height of the array structure is 50 to 100 μm, preferably 60 to 90 μm, more preferably 65 to 85 μm, and more preferably 70 to 80 μm.

[0059] In the present invention, the method for depositing the silane compound on the surface of the coating with the array structure is to immerse the coating with the array structure in a silane compound solution, remove it, and then dry it.

[0060] In the present invention, the mass concentration of the silane compound solution is 0.5-5%, preferably 1-4%, more preferably 2-3%, and more preferably 2.5%; the soaking time is 8-48 hours, preferably 12-40 hours, more preferably 15-30 hours, more preferably 18-25 hours, and more preferably 20-22 hours; the drying time is 2-24 hours, preferably 5-20 hours, more preferably 8-18 hours, and more preferably 13-15 hours.

[0061] In the present invention, the silane compound in step 4) comprises one or more of 1H,1H,2H,2H-perfluorodecyltriethoxysilane, trimethylchlorosilane, hexamethyldisilazane and dodecyltrimethoxysilane.

[0062] In the present invention, the pressure of the sandblasting in step 1) is 0.7-0.9 MPa, preferably 0.75-0.85 MPa, more preferably 0.8 MPa; the angle of the sandblasting is 40-60°, preferably 45-55°, more preferably 50°.

[0063] In the present invention, the base material is preferably cleaned before sandblasting, and more preferably, is first cleaned with ethanol and then ultrasonically cleaned with acetone.

[0064] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0065] Example 1

[0066] 1) 2 g of carbon nanotubes with a particle size of 50 nm were added to anhydrous ethanol and ultrasonically dispersed for 30 min. Then, 1 mL of 1H,1H,2H,2H-perfluorodecyltriethoxysilane was added and ultrasonically dispersed for another 30 min. The dispersion was placed in a hydrothermal reactor lined with polytetrafluoroethylene and reacted at 120° C. for 8 h. The mixed solution was centrifuged and the precipitate was washed three times with anhydrous ethanol. The precipitate was placed in a vacuum drying oven and dried at 80° C. for 24 h to obtain hydrophobic carbon nanotubes.

[0067] 2) n-octylamine and m-xylidine were mixed in a molar ratio of 2:1 and magnetically stirred at a speed of 300 r / min for 10 minutes to obtain a curing agent.

[0068] 3) 1.5 g of hydrophobic carbon nanotubes and 15 g of epoxy resin E51 were mixed, and magnetic stirring was performed at 70° C. and 500 rpm for 30 min. Then, 5 g of a curing agent was added and slowly stirred with a glass rod for 10 min to uniformly disperse the system to obtain a coating.

[0069] 4) The substrate was pretreated by cutting 5083 aluminum alloy into aluminum alloy specimens of 30 mm × 30 mm × 5 mm, cleaning with ethanol, soaking in acetone for ultrasonic cleaning for 30 min, rinsing with deionized water, and drying. Finally, the specimens were sandblasted at a pressure of 0.8 MPa and a blasting angle of 50°.

[0070] 5) The coating was applied to the treated aluminum alloy sample using a 150 μm coating rod and cured in a drying oven at 70°C for 2 hours, followed by curing at 100°C for 1 hour to obtain an initial coating. A femtosecond laser was used to etch array pillars with a spacing of 2 μm and a height of 50 μm on the surface of the initial coating. After etching, the aluminum alloy sample was ultrasonically cleaned in deionized water for 30 minutes. After cleaning, the sample was immersed in a 2 wt% solution of 1H,1H,2H,2H-perfluorodecyltriethoxysilane for 12 hours. After immersion, the sample was dried in a drying oven for 4 hours to obtain an aluminum alloy material with a functional superhydrophobic shape memory coating on its surface.

[0071] The coating obtained in this example was subjected to a contact angle test, and the results showed that the water contact angle was 156° and the rolling angle was 3°, indicating that the coating had superhydrophobic properties.

[0072] In addition, the shape memory performance of the coating obtained in this example was tested. The coating was destroyed at 90°C using a tablet press (pressure of 0.3 MPa). After destruction, the contact angle of the coating was 95° and the rolling angle was 6°, indicating that the coating had lost its superhydrophobicity and the pillars on the surface of the coating became flat. After the coating was subjected to a voltage of 15V for 20 minutes, the contact angle of the coating was 156° and the rolling angle was 3°. The superhydrophobic performance of the coating was restored. After 20 cycles of pressurized destruction and power-on recovery experiments, the coating still maintained its superhydrophobicity.

[0073] The above tests confirm that the coating of this embodiment has excellent superhydrophobicity and shape memory function, and the shape activation method is electrical activation.

[0074] Example 2

[0075] 1) 2 g of Fe3O4 with a particle size of 50 nm was added to anhydrous ethanol and ultrasonically dispersed for 30 min. Then, 1 mL of 1H,1H,2H,2H-perfluorodecyltriethoxysilane was added and ultrasonically dispersed for another 30 min. The dispersion was placed in a hydrothermal reactor lined with polytetrafluoroethylene and reacted at 120°C for 8 h. The mixed solution was centrifuged and the precipitate was washed three times with anhydrous ethanol. The precipitate was placed in a vacuum drying oven and dried at 80°C for 24 h to obtain hydrophobic nano-Fe3O4.

[0076] 2) n-octylamine and m-xylidine were mixed in a molar ratio of 2:1 and magnetically stirred at a speed of 300 r / min for 10 minutes to obtain a curing agent.

[0077] 3) 1.5 g of hydrophobic nano-Fe3O4 was mixed with 15 g of epoxy resin E51, and magnetically stirred at 70°C and 500 rpm for 30 min. Then, 5 g of curing agent was added and slowly stirred with a glass rod for 10 min to uniformly disperse the system to obtain a coating.

[0078] 4) The substrate was pretreated by cutting 5083 aluminum alloy into aluminum alloy specimens of 30 mm × 30 mm × 5 mm, cleaning with ethanol, soaking in acetone for ultrasonic cleaning for 30 min, rinsing with deionized water, and drying. Finally, the specimens were sandblasted at a pressure of 0.8 MPa and a blasting angle of 50°.

[0079] 5) The coating was applied to the treated aluminum alloy sample using a 150 μm coating rod and cured in a drying oven at 70°C for 2 hours, followed by curing at 100°C for 1 hour to obtain an initial coating. A femtosecond laser was used to etch array pillars with a spacing of 2 μm and a height of 50 μm on the surface of the initial coating. After etching, the aluminum alloy sample was ultrasonically cleaned in deionized water for 30 minutes. After cleaning, the sample was immersed in a 2 wt% solution of 1H,1H,2H,2H-perfluorodecyltriethoxysilane for 12 hours. After immersion, the sample was dried in a drying oven for 4 hours to obtain an aluminum alloy material with a functional superhydrophobic shape memory coating on its surface.

[0080] The coating obtained in this example was subjected to a contact angle test, and the results showed that the water contact angle was 155° and the rolling angle was 3°, indicating that the coating had superhydrophobic properties.

[0081] In addition, the shape memory performance of the coating obtained in this example was tested. The coating was destroyed at 90°C using a tablet press (pressure of 0.3 MPa). After destruction, the contact angle of the coating was 97° and the rolling angle was 7°, indicating that the coating had lost its superhydrophobicity and the pillars on the surface of the coating became flat. The damaged part of the coating was then irradiated with infrared light to complete self-repair. After repair, the contact angle of the coating was 156° and the rolling angle was 3°. The superhydrophobic performance of the coating was restored. After 20 cycles of pressurized destruction and infrared light irradiation recovery experiments, the coating still maintained its superhydrophobicity.

[0082] The above tests confirm that the coating of this embodiment has excellent superhydrophobicity and shape memory function, and the shape activation method is infrared light activation.

[0083] Example 3

[0084] 1) 2 g of ZnFe2O4 with a particle size of 50 nm was added to anhydrous ethanol and ultrasonically dispersed for 30 min. Then, 1 mL of 1H,1H,2H,2H-perfluorodecyltriethoxysilane was added and ultrasonically dispersed for another 30 min. The dispersion was placed in a hydrothermal reactor lined with polytetrafluoroethylene and reacted at 120°C for 8 h. The mixed solution was centrifuged and the precipitate was washed three times with anhydrous ethanol. The precipitate was placed in a vacuum drying oven and dried at 80°C for 24 h to obtain hydrophobic nano-ZnFe2O4.

[0085] 2) n-octylamine and m-xylidine were mixed in a molar ratio of 2:1 and magnetically stirred at a speed of 300 r / min for 10 minutes to obtain a curing agent.

[0086] 3) 1.5 g of hydrophobic nano-ZnFe2O4 and 15 g of epoxy resin E51 were mixed and magnetically stirred at 70°C and 500 rpm for 30 min. Then 5 g of curing agent was added and slowly stirred with a glass rod for 10 min to uniformly disperse the system to obtain a coating.

[0087] 4) The substrate was pretreated by cutting 5083 aluminum alloy into aluminum alloy specimens of 30 mm × 30 mm × 5 mm, cleaning with ethanol, soaking in acetone for ultrasonic cleaning for 30 min, rinsing with deionized water, and drying. Finally, the specimens were sandblasted at a pressure of 0.8 MPa and a blasting angle of 50°.

[0088] 5) The coating was applied to the treated aluminum alloy sample using a 150 μm coating rod and cured in a drying oven at 70°C for 2 hours, followed by curing at 100°C for 1 hour to obtain an initial coating. A femtosecond laser was used to etch array pillars with a spacing of 2 μm and a height of 50 μm on the surface of the initial coating. After etching, the aluminum alloy sample was ultrasonically cleaned in deionized water for 30 minutes. After cleaning, the sample was immersed in a 2 wt% solution of 1H,1H,2H,2H-perfluorodecyltriethoxysilane for 2 hours. After immersion, the sample was dried in a drying oven for 4 hours to obtain an aluminum alloy material with a functional superhydrophobic shape memory coating on its surface.

[0089] Contact angle tests on the coating obtained in this example showed a water contact angle of 155° and a rolling angle of 2°, indicating superhydrophobic properties. A VNA (vector network analyzer) in coaxial mode was used to test the microwave absorption performance of the aluminum alloy material with the functional superhydrophobic shape memory coating prepared in this example. The coating had a minimum reflection loss of -54.63 dB, a matching thickness of 2.5 mm, and an effective absorption bandwidth of 3.52 GHz.

[0090] In addition, the shape memory performance of the coating obtained in this example was tested. The coating was destroyed using a tablet press (pressure of 0.3 MPa) at 90°C. After destruction, the contact angle of the coating was 99° and the rolling angle was 7°, indicating that the coating had lost its superhydrophobicity and the columns on the surface of the coating became flat. The coating was then restored at 90°C. After recovery, the contact angle of the coating was 156° and the rolling angle was 3°. The superhydrophobic performance of the coating was restored. After 20 cycles of pressurized destruction and high-temperature recovery, the coating still maintained its superhydrophobicity.

[0091] The above tests confirm that the coating of this embodiment has excellent superhydrophobicity and shape memory function, and the coating has good wave absorbing performance.

[0092] Example 4

[0093] 1) 2 g of nanozyme Ni-V metal oxide with a particle size of 50 nm was added to anhydrous ethanol and ultrasonically dispersed for 30 min. Then 1 mL of 1H,1H,2H,2H-perfluorodecyltriethoxysilane was added and ultrasonically dispersed for another 30 min. The dispersion was placed in a hydrothermal reactor lined with polytetrafluoroethylene and reacted at 120°C for 8 h. The mixed solution was centrifuged and the precipitate was washed three times with anhydrous ethanol. The precipitate was placed in a vacuum drying oven and dried at 80°C for 24 h to obtain hydrophobic nanozyme Ni-V metal oxide.

[0094] 2) n-octylamine and m-xylidine were mixed in a molar ratio of 2:1 and magnetically stirred at a speed of 300 r / min for 10 minutes to obtain a curing agent.

[0095] 3) 1.5 g of hydrophobic nanozyme Ni-V metal oxide was mixed with 15 g of epoxy resin E51 and magnetically stirred at 70°C and 500 rpm for 30 min. Then 5 g of curing agent was added and slowly stirred with a glass rod for 10 min to uniformly disperse the system to obtain a coating.

[0096] 4) The substrate was pretreated by cutting 5083 aluminum alloy into aluminum alloy specimens of 30 mm × 30 mm × 5 mm, cleaning with ethanol, soaking in acetone for ultrasonic cleaning for 30 min, rinsing with deionized water, and drying. Finally, the specimens were sandblasted at a pressure of 0.9 MPa and an angle of 60°.

[0097] 5) The coating was applied to the treated aluminum alloy sample using a 150 μm coating rod and cured in a drying oven at 70°C for 2 hours, followed by curing at 100°C for 1 hour to obtain an initial coating. A femtosecond laser was used to etch array pillars with a spacing of 2 μm and a height of 50 μm on the surface of the initial coating. After etching, the aluminum alloy sample was ultrasonically cleaned in deionized water for 30 minutes. After cleaning, the sample was immersed in a 2 wt% solution of 1H,1H,2H,2H-perfluorodecyltriethoxysilane for 2 hours. After immersion, the sample was dried in a drying oven for 4 hours to obtain an aluminum alloy material with a functional superhydrophobic shape memory coating on its surface.

[0098] The coating obtained in this embodiment was subjected to a contact angle test, and the results showed that the water contact angle was 157° and the rolling angle was 4°, indicating that the coating had superhydrophobic properties. The antibacterial properties of the aluminum alloy material with a functional superhydrophobic shape memory coating on the surface prepared in this embodiment were tested, and the specific detection method was as follows: Escherichia coli and Bacillus hematoxylin were stored in glycerol at -80°C, and then cultured in 50mL of 2216 medium at 37°C and 180rpm in a shaker to 108 colony forming units / mL. After the colony was placed on the aluminum alloy material with a functional superhydrophobic shape memory coating on the surface for 24 hours, the sterilization rate was calculated according to the standard electroplating method, and the sterilization rate of the coating could reach 80%.

[0099] In addition, the shape memory performance of the coating obtained in this example was tested. The coating was destroyed at 90°C using a tablet press (pressure of 0.3 MPa). After destruction, the contact angle of the coating was 101° and the rolling angle was 6°, indicating that the coating had lost its superhydrophobicity and the columns on the surface of the coating had become flat. The coating was then restored at 90°C. After recovery, the contact angle of the coating was 156° and the rolling angle was 3°. The superhydrophobic performance of the coating was restored. After 20 cycles of pressurized destruction and high-temperature recovery, the coating still maintained its superhydrophobicity.

[0100] The above tests confirm that the coating of this embodiment has excellent superhydrophobicity and shape memory function, and the coating has good antibacterial performance.

[0101] Example 5

[0102] 1) 3 g of carbon nanotubes with a particle size of 100 nm were added to anhydrous ethanol and ultrasonically dispersed for 30 min. Then, 2 g of trimethylsilyl chloride was added and ultrasonically dispersed for another 30 min. The dispersion was placed in a hydrothermal reactor lined with polytetrafluoroethylene and reacted at 140° C. for 18 h. The mixed solution was centrifuged and the precipitate was washed three times with anhydrous ethanol. The precipitate was placed in a vacuum drying oven and dried at 80° C. for 24 h to obtain hydrophobic carbon nanotubes.

[0103] 2) 2 g of hydrophobic carbon nanotubes were mixed with 20 g of polyester (PET), and magnetically stirred at 50° C. and 500 rpm for 100 min. 8 g of a curing agent, hydroxyalkylamide (HAA), was added, and the mixture was slowly stirred with a glass rod for 10 min to uniformly disperse the system to obtain a coating.

[0104] 3) The substrate was pretreated by cutting 5083 aluminum alloy into 30 mm × 30 mm × 5 mm aluminum alloy specimens, cleaning them with ethanol, immersing them in acetone for ultrasonic cleaning for 30 min, rinsing them with deionized water, and drying them. Finally, they were sandblasted at a pressure of 0.8 MPa and a blasting angle of 50°.

[0105] 4) The coating was applied to the treated aluminum alloy sample using a 150 μm coating rod and cured in a drying oven at 90°C for 1.5 hours, followed by curing at 110°C for 1 hour to obtain an initial coating. A femtosecond laser was used to etch array pillars with a spacing of 2 μm and a height of 50 μm on the surface of the initial coating. After etching, the aluminum alloy sample was ultrasonically cleaned in deionized water for 30 minutes. After cleaning, it was immersed in a 3 wt% trimethylchlorosilane solution for 15 hours. After immersion, it was dried in a drying oven for 4 hours to obtain an aluminum alloy material with a functional superhydrophobic shape memory coating on its surface.

[0106] The coating obtained in this example was subjected to a contact angle test, and the results showed that the water contact angle was 157° and the rolling angle was 3°, indicating that the coating had superhydrophobic properties.

[0107] In addition, the shape memory performance of the coating obtained in this example was tested. The coating was destroyed using a tablet press (pressure of 0.3 MPa) at 90°C. The contact angle of the coating after destruction was 98° and the rolling angle was 7°, indicating that the coating had lost its superhydrophobicity and the columns on the surface of the coating became flat. The coating was then restored at 90°C. After recovery, the contact angle of the coating was 155° and the rolling angle was 3°. The superhydrophobic performance of the coating was restored. After 20 cycles of pressurized destruction and high-temperature recovery, the coating still maintained its superhydrophobicity.

[0108] Example 6

[0109] 1) 3 g of nanozyme Ni-V metal oxide with a particle size of 50 nm was added to anhydrous ethanol and ultrasonically dispersed for 30 min. Then 0.5 g of dodecyltrimethoxysilane was added and ultrasonically dispersed for 45 min. The dispersion was placed in a hydrothermal reactor lined with polytetrafluoroethylene and reacted at 180°C for 10 h. The mixed solution was centrifuged and the precipitate was washed three times with anhydrous ethanol. The precipitate was placed in a vacuum drying oven and dried at 80°C for 20 h to obtain hydrophobic nanozyme Ni-V metal oxide.

[0110] 2) n-octylamine and m-xylidine were mixed at a molar ratio of 2.5:1 and magnetically stirred at a speed of 350 r / min for 15 minutes to obtain a curing agent.

[0111] 3) 2.2 g of hydrophobic nanozyme Ni-V metal oxide was mixed with 22 g of polyimide, and magnetically stirred at 100° C. and 500 rpm for 20 min. Then 8 g of curing agent was added and slowly stirred with a glass rod for 20 min to uniformly disperse the system to obtain a coating.

[0112] 4) The substrate was pretreated by cutting 5083 aluminum alloy into aluminum alloy specimens of 30 mm × 30 mm × 5 mm, cleaning with ethanol, soaking in acetone for ultrasonic cleaning for 30 min, rinsing with deionized water, and drying. Finally, the specimens were sandblasted at a pressure of 0.8 MPa and a blasting angle of 50°.

[0113] 5) The coating was applied to the treated aluminum alloy sample using a 150 μm coating rod and cured in a drying oven at 70°C for 2 hours, followed by curing at 100°C for 1 hour to obtain an initial coating. A femtosecond laser was used to etch array pillars with a spacing of 5 μm and a height of 70 μm on the surface of the initial coating. After etching, the aluminum alloy sample was ultrasonically cleaned in deionized water for 40 minutes. After cleaning, it was immersed in a 2.5 wt% dodecyltrimethoxysilane solution for 12 hours. After immersion, it was dried in a drying oven for 4 hours to obtain an aluminum alloy material with a functional superhydrophobic shape memory coating on its surface.

[0114] The coating obtained in this example was subjected to a contact angle test, and the results showed that the water contact angle was 158° and the rolling angle was 3°, indicating that the coating had superhydrophobic properties.

[0115] In addition, the shape memory performance of the coating obtained in this example was tested. The coating was destroyed at 90°C using a tablet press (pressure of 0.3 MPa). After destruction, the contact angle of the coating was 100° and the rolling angle was 7°, indicating that the coating had lost its superhydrophobicity and the columns on the surface of the coating became flat. The coating was then restored at 90°C. After recovery, the contact angle of the coating was 155° and the rolling angle was 3°. The superhydrophobic performance of the coating was restored. After 20 cycles of pressurized destruction and high-temperature recovery, the coating still maintained its superhydrophobicity.

[0116] Example 7

[0117] 1) 2 g of carbon nanotubes with a particle size of 50 nm were added to anhydrous ethanol and ultrasonically dispersed for 30 min. Then, 1 g of hexamethyldisilazane was added and ultrasonically dispersed for another 30 min. The dispersion was placed in a hydrothermal reactor lined with polytetrafluoroethylene and reacted at 120° C. for 8 h. The mixed solution was centrifuged and the precipitate was washed three times with anhydrous ethanol. The precipitate was placed in a vacuum drying oven and dried at 80° C. for 24 h to obtain hydrophobic carbon nanotubes.

[0118] 2) 1.5 g of hydrophobic carbon nanotubes was mixed with 15 g of polyester (PET), and magnetically stirred at 70° C. and 500 rpm for 30 min. 5 g of curing agent HAA was added and slowly stirred with a glass rod for 10 min to uniformly disperse the system to obtain a coating.

[0119] 3) The substrate was pretreated by cutting 5083 aluminum alloy into 30 mm × 30 mm × 5 mm aluminum alloy specimens, cleaning them with ethanol, immersing them in acetone for ultrasonic cleaning for 30 min, rinsing them with deionized water, and drying them. Finally, they were sandblasted at a pressure of 0.8 MPa and a blasting angle of 50°.

[0120] 4) The coating was applied to the treated aluminum alloy sample using a 150 μm coating rod and cured in a drying oven at 70°C for 2 hours, followed by curing at 100°C for 1 hour to obtain an initial coating. A femtosecond laser was used to etch array pillars with a spacing of 15 μm and a height of 65 μm on the surface of the initial coating. After etching, the aluminum alloy sample was ultrasonically cleaned in deionized water for 30 minutes. After cleaning, it was immersed in a 2 wt% hexamethyldisilazane solution for 12 hours. After immersion, it was dried in a drying oven for 4 hours to obtain an aluminum alloy material with a functional superhydrophobic shape memory coating on its surface.

[0121] The coating obtained in this example was subjected to a contact angle test, and the results showed that the water contact angle was 158° and the rolling angle was 3°, indicating that the coating had superhydrophobic properties.

[0122] In addition, the shape memory performance of the coating obtained in this example was tested. The coating was destroyed at 90°C using a tablet press (pressure of 0.3 MPa). After destruction, the contact angle of the coating was 97° and the rolling angle was 7°, indicating that the coating had lost its superhydrophobicity and the columns on the surface of the coating became flat. The coating was then restored at 90°C. After recovery, the contact angle of the coating was 157° and the rolling angle was 4°. The superhydrophobic performance of the coating was restored. After 20 cycles of pressurized destruction and high-temperature recovery, the coating still maintained its superhydrophobicity.

[0123] Comparative Example 1

[0124] The difference between this comparative example and Example 1 is that in the process of preparing the coating, the amount of epoxy resin E51 added is 15 g, and the amount of hydrophobic carbon nanotubes added is 3 g. Others are the same as Example 1.

[0125] The coating obtained in this comparative example has been subjected to shape memory performance test, and coating is destroyed with tablet press (pressure is 0.3MPa) at 90 DEG C, and the contact angle of coating after destruction is 97 °, and roll angle is 7 °, shows that coating has lost super-hydrophobicity, and the column of coating surface becomes flat; After coating is passed through 15V voltage 30min, the contact angle of coating is 156 °, and roll angle is 3 °, and the super-hydrophobicity of coating is recovered, but recovery time is extended. This is because after hydrophobic carbon nanotube content is too high, agglomeration occurs, so as to cause the conductivity of coating to decline, recovery time to be extended. Simultaneously, the toughness variation of epoxy resin coating deteriorates, so that brittle fracture occurs when coating is destroyed at room temperature, and coating is lost super-hydrophobicity.

[0126] Comparative Example 2

[0127] The difference between this comparative example and Example 2 is that in the process of preparing the coating, the added amount of epoxy resin E51 is 15g, and the added amount of hydrophobic nano-Fe3O4 is 3g. The rest is the same as Example 2.

[0128] The coating obtained by this comparative example has been tested for shape memory performance, and at 90 DEG C, with tablet press (pressure is 0.3MPa), coating is destroyed, and the contact angle of coating after destruction is 97 °, and rolling angle is 7 °, shows that coating has lost super-hydrophobicity, and the pillar of coating surface becomes flat; Afterwards, infrared light is used to irradiate the destroyed coating, and coating contact angle and rolling angle recovery rate and recovery rate are different everywhere. This is because when hydrophobic nano Fe3O4 content is too high, agglomeration can occur, so as to cause hydrophobic nano Fe3O4 in coating to be unevenly distributed, and even there is no hydrophobic nano Fe3O4 in large area coating position, so that coating recovery rate and recovery rate are different everywhere. Simultaneously, the toughness variation of epoxy resin coating deteriorates, so that brittle fracture occurs when coating is destroyed at room temperature, and coating is lost super-hydrophobicity.

[0129] Comparative Example 3

[0130] The difference between this comparative example and Example 3 is that in the process of preparing the coating, the amount of epoxy resin E51 added is 15g, and the amount of hydrophobic nano ZnFe2O4 added is 3g. The rest is the same as Example 3.

[0131] The wave absorbing performance of the aluminum alloy material with a coating on the surface prepared in this comparative example was tested. The minimum reflection loss of the coating reached -30.16 dB, the matching thickness was 4.5 mm, and the effective absorption bandwidth was 1.49 GHz.

[0132] The coating obtained by this comparative example has been tested for shape memory performance, and at 90 DEG C, coating is destroyed with tablet press (pressure is 0.3MPa), and the contact angle of destruction rear coating is 99 °, and roll angle is 7 °, shows that coating has lost super-hydrophobicity, and the column of coating surface becomes flat; Afterwards coating is placed at a temperature of 90 DEG C and recovered, the contact angle of recovery rear coating coating is 154 °, and roll angle is 2 °, and its super-hydrophobicity is recovered. This is because when hydrophobic nano ZnFe2O4 content is too high, agglomeration will occur, causing the toughness variation of epoxy coating to deteriorate, so that brittle fracture occurs when coating is destroyed at room temperatures, makes coating lose super-hydrophobicity, and ZnFe2O4 agglomeration also greatly reduces the wave absorbing performance of coating.

[0133] Comparative Example 4

[0134] The difference between this comparative example and Example 4 is that in the process of preparing the coating, the amount of epoxy resin E51 added is 15 g, the amount of hydrophobic nanozyme Ni-V metal oxide added is 3 g, and the rest is the same as Example 4.

[0135] The coating obtained in this comparative example is subjected to shape memory performance test, and coating is destroyed with tablet press (pressure is 0.3MPa) at 90 DEG C, and the contact angle of the coating after destruction is 99 °, and the rolling angle is 7 °, indicating that coating has lost super-hydrophobicity, and the pillar of coating surface becomes flat;Later coating is placed at a temperature of 90 DEG C and restored, and the contact angle of the coating after recovery is 159 °, and the rolling angle is 4 °, and the super-hydrophobicity of coating is restored. This is because when hydrophobic nanozyme Ni-V metal oxide content is too high, agglomeration will occur, causing the toughness variation of epoxy coating to deteriorate, so that brittle fracture occurs when coating is destroyed at room temperature, and coating is lost super-hydrophobicity.

[0136] In addition, the antibacterial performance of the coating obtained in this comparative example was tested, and the bactericidal rate of the coating was 60%, indicating that the agglomeration of the hydrophobic nanozyme Ni-V metal oxide greatly reduced the antibacterial performance of the coating.

[0137] The present invention uses epoxy resin E51 with shape memory performance as a film-forming material, cooperates with hydrophobic inorganic nanoparticles, and obtains a coating with a uniform array surface by a simple smearing method and a photolithography method. The contact angle with water is greater than 150°, and the rolling angle is less than 5°. It has excellent super-hydrophobicity. The coating is added with hydrophobic nano ZnFe2O4 or nano enzyme Ni-V metal oxide, which can make the coating have wave absorption or sterilization performance. After the coating is compressed or mechanically destroyed, the surface morphology will change, and the coating will lose super-hydrophobicity. However, after being treated by a method of heat treatment, infrared light irradiation or energization, the coating can restore its super-hydrophobicity. When the coating is added with hydrophobic nano Fe3O4 and carbon nanotubes, after losing super-hydrophobicity, the coating can restore its super-hydrophobicity not only by heat treatment, but also by infrared light or energization.

[0138] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a functional super-hydrophobic shape memory coating, characterized in that: The following steps are involved: 1) Sandblasting the base material; 2) applying the coating to the base material and heating and curing it to obtain an initial coating; 3) performing photolithographic processing on the initial coating to obtain a coating having an array structure; 4) Depositing silane compounds on the surface of the coating with an array structure to obtain a functional superhydrophobic shape memory coating; The coating comprises the following raw materials in parts by mass: 10 to 25 parts of a film-forming substance, 5 to 10 parts of a curing agent, and 0.5 to 5 parts of a hydrophobic inorganic nanomaterial; The mass ratio of the film-forming substance to the hydrophobic inorganic nanomaterial is 10:0.5-2; The preparation method of the hydrophobic inorganic nanomaterial is as follows: 1) dispersing inorganic nanoparticles and a low surface energy modifier in ethanol to obtain a dispersion; 2) subjecting the dispersion to a hydrothermal reaction to obtain a hydrophobic inorganic nanomaterial; The temperature of the hydrothermal reaction is 80-200° C., and the time of the hydrothermal reaction is 8-48 hours; The inorganic nanomaterials include one or more of carbon nanotubes, nano Fe3O4, nano ZnFe2O4 and nano enzyme Ni-V metal oxide; The particle size of the inorganic nanomaterial is 10 to 500 nm; The low surface energy modifier comprises one or more of 1H,1H,2H,2H-perfluorodecyltriethoxysilane, trimethylchlorosilane, hexamethyldisilazane and dodecyltrimethoxysilane.

2. The method for preparing a functional super-hydrophobic shape memory coating according to claim 1, wherein: The film-forming material comprises one or more of epoxy resin, polyester and polyimide; The curing agent is a hydroxyalkylamide or a mixture of n-octylamine and m-xylidine; The molar ratio of n-octylamine to m-xylidine is 1-3:1; The hydrophobic inorganic nanomaterial is an inorganic nanomaterial that has been modified to have low surface energy.

3. The method for preparing a functional super-hydrophobic shape memory coating according to claim 1 or 2, characterized in that: The coating is prepared by reacting hydrophobic inorganic nanoparticles with a film-forming substance to obtain a blend, and then mixing the blend with a curing agent to obtain the coating; The reaction temperature is 50-100° C., and the reaction time is 20-120 min.

4. The method for preparing a functional super-hydrophobic shape memory coating according to claim 3, wherein: The pitch of the array structure is 1-30 μm, and the height of the array structure is 50-100 μm.

5. The method for preparing a functional super-hydrophobic shape memory coating according to claim 4, wherein: The method for depositing the silane compound on the surface of the coating with the array structure is to immerse the coating with the array structure in a silane compound solution, remove it, and then dry it.

6. The method for preparing a functional super-hydrophobic shape memory coating according to claim 5, characterized in that: The mass concentration of the silane compound solution is 0.5-5%, the soaking time is 8-48 hours, and the drying time is 2-24 hours; The silane compound comprises one or more of 1H,1H,2H,2H-perfluorodecyltriethoxysilane, trimethylchlorosilane, hexamethyldisilazane and dodecyltrimethoxysilane.

7. A functional superhydrophobic shape memory coating prepared by the preparation method according to any one of claims 1 to 6.