Anticorrosive self-repairing super-amphiphobic coating film and preparation method thereof

Abstract

The application discloses an anti-corrosion self-repairing super-amphiphobic coating film and a preparation method thereof, and belongs to the technical field of high polymer coating materials. The coating film is sequentially composed of a nanoparticle skeleton layer, a dynamic borate ester bond layer and a super-amphiphobic functional layer. The three-layer gradient design cooperatively realizes micro / nano structure stability, self-repairing and super-amphiphobic functions. The skeleton layer takes SiO2-TiO2 composite nanoparticles as a substrate to provide support. The dynamic borate ester bond layer forms a dynamic network through organic boron compound polycondensation, and is endowed with self-repairing capability and enhanced interface combination. The super-amphiphobic functional layer is formed by grafting fluorine-containing organosilicon compounds, and has hydrophobic and oleophobic properties. The multilevel structure is constructed in steps, the reaction condition is mild, the operation is simple, the cost is low, and the method is suitable for large-scale industrial preparation. The coating film has excellent super-amphiphobic performance and interface adhesion performance, and the super-amphiphobic performance of the coating film can still be kept stable in long-term use or complex environment, and the problem that existing super-amphiphobic materials are prone to damage is effectively solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high polymer coating materials, and particularly relates to an anti-corrosion self-repairing super-amphiphobic coating film and a preparation method thereof. BACKGROUND

[0002] Wettability is one of the core properties of a material surface, which determines the spreading and adhesion of a liquid on a solid surface. In the past three decades, with the breakthroughs in nanofabrication technology and bionics research, the regulation of wettability has rapidly progressed from basic theoretical research to functional application, forming extreme wettability surface systems represented by superhydrophobic, superhydrophilic, and superamphiphobic surfaces. Traditional superhydrophobic surfaces (contact angle > 150°) achieve efficient water repellency by mimicking the micro / nano structures and low surface energy surfaces of biological organisms, such as the surfaces of lotus leaves, butterfly wings, rose petals, water strider legs, and mussels, all of which exhibit superhydrophobicity. Such superhydrophobic materials have shown great potential in fields such as self-cleaning, oil-water separation, ice prevention, droplet manipulation, anti-fouling, corrosion prevention, anti-pollution, and drag reduction.

[0003] However, with the development of industry and technology, single hydrophobicity has been difficult to meet the application requirements in complex environments. For example, in the treatment of oil-containing wastewater, marine anti-biofouling, and metal corrosion protection, the material surface needs to resist the wetting and adhesion of both low surface energy liquids (such as oils and organic solvents) and high surface energy liquids (such as water), i.e., to achieve superamphiphobic wettability (simultaneously hydrophobic and oleophobic, with contact angles both > 150°). However, at present, superhydrophobic / superoleophobic materials still face severe challenges in the process of popularization in practical engineering applications. The main technical bottleneck is the poor structural stability of the material surface. When the material is exposed to a complex environment, mechanical external forces or chemical erosion will directly act on the material surface, which not only causes physical damage to the micro / nano structures, but also causes irreversible changes in the surface chemical composition. This dual damage effect leads to the gradual decay of the inherent superamphiphobic properties of the material, and even complete failure, which severely limits the widespread application of superamphiphobic materials in practical engineering.

[0004] Therefore, developing superamphiphobic materials with excellent environmental tolerance and self-repairing function has become a key technical problem in this field. SUMMARY

[0005] In view of the fact that single hydrophobicity cannot meet the requirements of complex environments, and that superhydrophobic / superoleophobic materials in practical engineering applications are damaged by mechanical external forces or chemical erosion when exposed to complex environments, which damages the micro / nano structures and changes the surface chemical composition, leading to the decay and failure of superamphiphobic properties, the present application aims to provide an anti-corrosion self-repairing superamphiphobic coating film and a preparation method thereof.

[0006] To achieve the above object, the present application adopts the following technical solutions to achieve the above object:

[0007] The present application provides an anticorrosive self-repairing super-amphiphobic coating film, which is composed of a nano-particle skeleton layer, a dynamic borate ester bond layer and a super-amphiphobic functional layer from inside to outside; the nano-particle skeleton layer is composed of SiO2-TiO2 composite nano-particles; the dynamic borate ester bond layer is formed on the surface of the SiO2-TiO2 composite nano-particles by polycondensation reaction of an organic boron compound; and the super-amphiphobic functional layer is grafted on the dynamic borate ester bond layer by a fluorine-containing organosilicon compound through a silicon-oxygen bond.

[0008] The organic boron compound is any one of 1,4-benzenediol, 4,4-biphenyldiboronic acid, 1,3,5-benzenetriol and 1,3-benzenediol.

[0009] Preferably, the organic boron compound is 1,4-benzenediol (BDBA).

[0010] The fluorine-containing organosilicon compound is any one of 1H,1H,2H,2H-perfluorodecyltriethoxysilane, 1H,1H,2H,2H-perfluorooctyltriethoxysilane, 1H,1H,2H,2H-perfluorodecyltrichlorosilane and trichloro(1H,1H,2H,2H-perfluorooctyl)silane (CAS No. 78560-45-9).

[0011] Preferably, the fluorine-containing organosilicon compound is 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES).

[0012] The contact angle of the anticorrosive self-repairing super-amphiphobic coating film is greater than 150°.

[0013] The present application provides a preparation method of the above-mentioned anticorrosive self-repairing super-amphiphobic coating film, which comprises the following steps:

[0014] Step 1: adding an organic boron compound and ammonia water into a SiO2-TiO2 composite nano-particle suspension to obtain emulsion 1;

[0015] Step 2: adding a fluorine-containing organosilicon compound and ethanol into the emulsion 1 in sequence to obtain emulsion 2;

[0016] Step 3: spraying the emulsion 2 on a pretreated substrate to obtain an anticorrosive self-repairing super-amphiphobic coating film.

[0017] In step 1, the mass ratio of the organic boron compound to the SiO2-TiO2 composite nano-particle is 1: (2-3), the reaction temperature is 25-30℃, and the reaction time is 4-6 hours.

[0018] In step 1, the tetraethyl orthosilicate, ammonia and anhydrous ethanol are mixed to react to obtain a SiO2 emulsion; butyl titanate is added to ultrasonic-assisted reaction to obtain a SiO2-TiO2 emulsion, which is dried to obtain SiO2-TiO2 composite nanoparticles; wherein the particle size of the SiO2-TiO2 composite nanoparticles is 20 nm to 100 nm.

[0019] Preferably, the volume ratio of the tetraethyl orthosilicate, ammonia and anhydrous ethanol is 1: (2-6): (4-8); the mixing reaction temperature is 20-30 DEG C, and the time is 4-8 h; the volume ratio of the butyl titanate to the SiO2 emulsion is 1: (8-12), and the ultrasonic-assisted reaction temperature is 20-30 DEG C, and the time is 8-12 h.

[0020] In step 2, the volume ratio of the fluorine-containing organosilicon compound, the emulsion 1 and the ethanol is 1: (4-6): (8-12); the reaction temperature is 65-75 DEG C, and the reaction time is 5-7 h.

[0021] In step 3, the substrate pretreatment is as follows: the substrate is sequentially cleaned with acetone, anhydrous ethanol and deionized water, dried with N2, then placed in a CuSO4 and NaCl mixed solution for chemical etching, dried with N2, then hydrothermally activated, cleaned, and dried.

[0022] The volume ratio of the CuSO4 solution to the NaCl solution in the CuSO4 and NaCl mixed solution is 1: (0.7-1); the hydrothermal activation temperature is 90-100 DEG C, and the time is 3-8 min.

[0023] Preferably, the concentration of the CuSO4 solution is 0.2 mol / L, and the concentration of the sodium chloride solution is 3 mol / L.

[0024] Preferably, the substrate is an aluminum sheet.

[0025] Compared with the prior art, the present application has the following beneficial effects:

[0026] The anti-corrosion self-repairing super-amphiphobic coating film provided by the application solves the stability and self-repairing problems of super-amphiphobic materials by constructing a multi-layer composite structure. The nanoparticle skeleton layer uses SiO2-TiO2 composite nanoparticles as a base, uses the high specific surface area of SiO2 and the photocatalytic stability of TiO2 to form a support structure with mechanical strength and chemical inertness, and provides physical anchoring points for subsequent functional layers. The dynamic borate ester bond layer forms a dynamic covalent network by polycondensation of organic boron compounds on the surface of nanoparticles. The reversible breaking-recombination characteristics of the borate ester bond of the dynamic borate ester bond layer endow the coating with the ability to repair itself by molecular chain rearrangement when damaged. Meanwhile, the dynamic borate ester bond layer serves as an intermediate transition layer to enhance the interface bonding between the skeleton layer and the functional layer. The super-amphiphobic functional layer is directionally grafted on the surface of the dynamic layer through the silicon-oxygen bond of a fluorine-containing organosilicon compound. The low surface energy characteristics of the perfluorinated long chain enable the coating to simultaneously have hydrophobic and oleophobic properties, and the chemical stability of the silicon-oxygen bond ensures the durability of the functional layer in complex environments. The gradient design of the three-layer structure realizes the synergy of micro / nano structure stability, dynamic self-repairing ability and super-amphiphobic function. The dynamic bond layer is a key innovation point, which repairs physical damage through reversible chemical bonds and maintains the integrity of the multi-layer structure through interface enhancement.

[0027] Further, the contact angle of the coating film is greater than 150°, and the coating film has extremely low adhesion to water and oil and can still maintain super-amphiphobic properties after mechanical damage or chemical erosion, thereby breaking through the technical bottleneck of traditional materials in which the contact angle decays due to insufficient structural or chemical stability.

[0028] The preparation method of the anti-corrosion self-repairing super-amphiphobic coating film provided by the application realizes the synergistic optimization of material performance by step-by-step construction of a multi-layer functional structure. The reaction conditions of each step are mild, the operation is simple, the cost is low, and the method is suitable for large-scale industrial production. SiO2-TiO2 composite nanoparticles are used as the skeleton layer, which provides mechanical support for subsequent functional layers due to its high specific surface area and rigid structure. The dynamic borate ester bond layer is formed by polycondensation of organic boron compounds and nanoparticles, and the reversible breaking and recombination characteristics of the dynamic chemical bond endow the coating film with self-repairing ability. The super-amphiphobic functional layer is formed on the surface of the dynamic bond layer by introducing a fluorine-containing organosilicon compound and ethanol to realize directional grafting through the silicon-oxygen bond. The low surface energy characteristics of fluorine and the nanostructure synergistically realize the super-hydrophobic and oleophobic functions. The spraying process is combined with substrate pretreatment technology to enhance the adhesion of the coating by adjusting the surface roughness and chemical activity. The curing process promotes the formation of stable cross-linked networks in each functional layer. The entire preparation process realizes the self-repairing ability of the coating film after damage while maintaining the super-amphiphobic properties through the layer-by-layer assembly of the nanoparticle skeleton, dynamic chemical bond and super-amphiphobic molecules. The synergistic effect of the three breaks through the technical bottleneck that traditional coating structures cannot simultaneously achieve stability and functional durability.

[0029] Further, the mass ratio of the organic boron compound and the nanoparticles is controlled at 1: (2~3), which ensures sufficient grafting of the boronic acid groups on the surface of the nanoparticles and avoids side reactions caused by excessive boronic acid monomers; a mild reaction temperature of 25-30℃ is selected, which meets the demand of the activation energy of the polycondensation reaction and avoids thermal decomposition of the dynamic bonds caused by high temperature; a reaction time of 4-6 hours is set, which ensures sufficient formation of the borate ester bonds and prevents nanoparticle agglomeration caused by long time, thereby solving the problems of uniform distribution and stable combination of the dynamic bond layer at the molecular level and laying a foundation for stable loading of the subsequent super-amphiphobic functional layer.

[0030] Further, the SiO2-TiO2 composite nanoparticles are constructed by a sol-gel method, tetraethyl orthosilicate is used as a silicon source precursor, hydrolysis and polycondensation reactions occur under the catalysis of ammonia to form SiO2 nanoparticles, the hydrolysis reaction in the alkaline environment is conducive to the formation of uniformly dispersed SiO2 emulsion at the nanoscale; butyl titanate is introduced as a titanium source, and ultrasonic assistance is used to promote uniform dispersion and hydrolysis of the titanate to generate TiO2, thereby forming a heterogeneous composite structure with SiO2; the ultrasonic treatment not only accelerates the hydrolysis kinetics process of the butyl titanate, but also realizes uniform composite of SiO2 and TiO2 at the nanoscale through cavitation effect; finally, the composite nanoparticles with a particle size controlled in the range of 20-100 nm are obtained through a drying process, which can not only ensure dense packing of the nanoparticles in the coating to form a stable skeleton, but also provide sufficient specific surface area for construction of the subsequent dynamic bond layer. The synergistic effect of the sol-gel method and ultrasonic assistance ensures the uniformity of the composite nanoparticles in chemical composition and microstructure, thereby providing a structural basis for stable construction of the subsequent dynamic borate ester bond layer and super-amphiphobic functional layer.

[0031] Further, by controlling the ratio of the fluorine-containing organosilicon compound, emulsion 1 and ethanol, as well as specific temperature and time parameters, controllable grafting of the super-amphiphobic functional layer is realized, which realizes high-density grafting of the low-surface-energy substance under the premise of maintaining the integrity of the micro / nano composite structure, thereby providing a stable super-amphiphobic performance basis for the coating film. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The infrared spectra of SiO2-TiO2 and SiO2-TiO2-BDBA-PFDTES prepared in Example 1 of the application, wherein (a) is the infrared spectrum of SiO2-TiO2, and (b) is the infrared spectrum of SiO2-TiO2-BDBA-PFDTES;

[0033] Figure 2 SEM characterization diagrams of the surface microstructure of the SiO2-TiO2-BDBA-PFDTES coating film of Example 1 of the application at different magnifications, wherein a is 36571 times, and b is 11000 times.

[0034] Figure 3 EDS diagram of the surface of the SiO2-TiO2-BDBA-PFDTES coating film of Example 1 of the present application;

[0035] Figure 4 Schematic diagram of the contact angle of water and oil on the SiO2-TiO2-BDBA-PFDTES coating film of Example 1 of the present application, wherein a is water and b is diiodomethane;

[0036] Figure 5 Schematic diagram of the adhesion of water and oil on the SiO2-TiO2-BDBA-PFDTES coating film of Example 1 of the present application, wherein a is water and b is diiodomethane;

[0037] Figure 6 Schematic diagram of the anti-fouling property of aluminum sheet in different solution environments before and after the SiO2-TiO2-BDBA-PFDTES treatment of Example 1 of the present application, wherein (a) is ink; (b) is milk; (c) is coffee; and (d) is black tea;

[0038] Figure 7 Schematic diagram of the contact angle change curve of the super-amphiphobic coating film in strong acid / alkali solution of Example 1 of the present application, wherein (a) is an acidic solution with pH = 1; and (b) is an alkaline solution with pH = 14;

[0039] Figure 8 Schematic diagram of the contact angle change curve of the self-repairing cycle of the SiO2-TiO2-BDBA-PFDTES coating film of Example 1 of the present application;

[0040] Figure 9 Self-repairing photo of the SiO2-TiO2-BDBA-PFDTES coating film of Example 1 of the present application under a fluorescence microscope. DETAILED DESCRIPTION

[0041] In order for those skilled in the art to understand the characteristics and effects of the present application, the following only explains and defines the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific words used herein have the same meaning as generally understood by those skilled in the art of the present application, and in case of conflict, the definition in the specification shall prevail.

[0042] Unless otherwise defined, the technical terms used in the following examples have the same meaning as generally understood by those skilled in the art to which the present application belongs. Unless otherwise specified, the test reagents used in the following examples are conventional biochemical reagents; and the experimental methods described, unless otherwise specified, are conventional methods.

[0043] Example 1

[0044] The embodiment provides an anti-corrosion self-repairing super-biphobic coating film, and a specific preparation method of the anti-corrosion self-repairing super-biphobic coating film is as follows:

[0045] (1) Substrate treatment

[0046] After polishing and polishing the aluminum sheet, the aluminum sheet is cleaned with acetone, anhydrous ethanol and deionized water under ultrasonic wave, and dried with nitrogen; the aluminum sheet is placed in a mixed solution (5 mL of 0.2 mol / L CuSO4 solution and 5 mL of 3 mol / L NaCl solution) for chemical etching for 2 minutes, ultrasonic cleaning with deionized water, and drying with N2; the etched aluminum sheet is placed in a 90 ℃ deionized water constant temperature water bath for heating for 8 min to promote the regeneration of surface hydroxyl (-OH) and improve the chemical bonding ability with the coating; after cleaning with anhydrous ethanol, the aluminum sheet is dried in a 100 ℃ oven for standby;

[0047] (2) Synthesis of SiO2-TiO2 composite nanoparticles

[0048] 12 mL of anhydrous ethanol and 8 mL of ammonia water are added to a round-bottom flask, and 2 mL of tetraethyl orthosilicate (TEOS) is slowly added dropwise under slow stirring, and the mixture is magnetically stirred at 25 ℃ for 6 h to obtain a white SiO2 nanoparticle emulsion by sol-gel method; 10 mL of the SiO2 nanoparticle emulsion is taken, 1 mL of butyl titanate (TBOT) is added, and the mixture is ultrasonically dispersed for 10 min, and then magnetically stirred at 25 ℃ for 10 h to obtain a SiO2-TiO2 emulsion, in which the hydrolysis and polycondensation of TBOT form a TiO2 shell layer on the surface of the SiO2 nanoparticles; the mixture is centrifuged and dried in a 100 ℃ oven to obtain SiO2-TiO2 composite nanoparticles;

[0049] (3) Synthesis of SiO2-TiO2-BDBA emulsion

[0050] 0.2 g of SiO2-TiO2 composite nanoparticles and 20 mL of ethanol are added to a round-bottom flask, and the mixture is ultrasonically stirred for 40 min, then 80 mg of 1,4-phenyldiboronic acid (BDBA) and 0.2 mL of ammonia water are added at 27 ℃, and the mixture is magnetically stirred for 5 h to obtain a SiO2-TiO2-BDBA emulsion;

[0051] (4) Synthesis of SiO2-TiO2-BDBA-PFDTES emulsion

[0052] 5 mL of SiO2-TiO2-BDBA emulsion is added to a round-bottom flask, and 10 mL of ethanol and 1 mL of 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) are sequentially added, and the mixture is reacted at 70 ℃ for 6 h to obtain a SiO2-TiO2-BDBA-PFDTES emulsion;

[0053] (5) coating spraying and curing

[0054] The SiO2-TiO2-BDBA-PFDTES coating film was prepared by spraying the SiO2-TiO2-BDBA PFDTES emulsion on the aluminum sheet with a nozzle diameter of 0.3 mm at a gas pressure of 0.2 Mpa, and curing in a drying oven at 70 DEG C for 4 h.

[0055] Referring to the attached Figure 1 The infrared spectrum of the SiO2-TiO2 composite nanoparticles and the SiO2-TiO2-BDBA-PFDTES coating film prepared in this example is shown in the attached -1 At 1085 cm-1, both samples have an absorption peak, which corresponds to the stretching vibration peak of Si-O-Ti, indicating that in the SiO2-TiO2 composite nanoparticles and the SiO2-TiO2-BDBA-PFDTES coating film, the grafting reaction of SiO2 and TiO2 is successful, and the Si-O-Ti chemical bond is formed. -1 The Si-C region is due to the presence of Si-C bonds in the introduced BDBA or PFDTES molecules, and compared with the SiO2-TiO2 spectrum, the change in this region indicates the introduction of new substances. -1 The absorption peak at 1193 cm-1 corresponds to the stretching vibration of C-F bond, and since the PFDTES molecule contains C-F bond, the appearance of this peak indicates that PFDTES is successfully introduced into the SiO2-TiO2 system. -1 The stretching vibration peak of B-O appears at 1317-1441 cm-1, which indicates that the BDBA molecule also successfully participates in the reaction and is introduced into the SiO2-TiO2-BDBA-PFDTES coating film system. Through the above infrared spectrum analysis, it can be confirmed that the SiO2-TiO2-BDBA-PFDTES coating film is successfully synthesized, and the existence of each chemical bond is determined.

[0056] Referring to the attached Figure 2 The SEM picture of the SiO2-TiO2-BDBA-PFDTES coating film prepared in this example is shown in the attached Figure 2As can be seen from the EDS scanning diagram of the surface of the SiO2-TiO2-BDBA-PFDTES coating film prepared in this embodiment, the C, O, Si, Ti, B and F elements are uniformly distributed on the surface of the coating film, which indicates that in the formation process of the coating film, the components are well mixed and dispersed at the molecular level, and there is no obvious element aggregation or segregation phenomenon. Uniform element distribution helps to ensure the consistency and stability of the performance of the coating film. The O, Si and Ti elements are mainly provided by SiO2-TiO2, which is the basic skeleton structure of the coating film, the B element is derived from BDBA, and the C and F elements are mainly derived from PFDTES. Therefore, because PFDTES successfully participates in the reaction and makes the C and F elements uniformly distributed on the surface of the coating film, the surface energy of the coating film surface is reduced, and the surface with low surface energy has the characteristics of repelling liquids (such as water and oil). Combined with the analysis of the microstructure (micro / nano structure) of the coating film before, the low surface energy characteristics and the micro / nano structure work together to make the coating film surface exhibit super-amphiphobic characteristics, i.e. having very high contact angles with water and oil, and liquids are difficult to wet the surface of the coating film.

[0057] Referring to the accompanying drawings Figure 3 As can be seen from the EDS scanning diagram of the surface of the SiO2-TiO2-BDBA-PFDTES coating film prepared in this embodiment, the C, O, Si, Ti, B and F elements are uniformly distributed on the surface of the coating film, which indicates that in the formation process of the coating film, the components are well mixed and dispersed at the molecular level, and there is no obvious element aggregation or segregation phenomenon. Uniform element distribution helps to ensure the consistency and stability of the performance of the coating film. The O, Si and Ti elements are mainly provided by SiO2-TiO2, which is the basic skeleton structure of the coating film, the B element is derived from BDBA, and the C and F elements are mainly derived from PFDTES. Therefore, because PFDTES successfully participates in the reaction and makes the C and F elements uniformly distributed on the surface of the coating film, the surface energy of the coating film surface is reduced, and the surface with low surface energy has the characteristics of repelling liquids (such as water and oil). Combined with the analysis of the microstructure (micro / nano structure) of the coating film before, the low surface energy characteristics and the micro / nano structure work together to make the coating film surface exhibit super-amphiphobic characteristics, i.e. having very high contact angles with water and oil, and liquids are difficult to wet the surface of the coating film.

[0058] Referring to the accompanying drawings Figure 4The contact angles of water and diiodomethane on the SiO2-TiO2-BDBA-PFDTES coating film prepared in the embodiment are measured by a contact angle measuring instrument, and the contact angles are 168.62° and 155.38° respectively. Generally, when the contact angle is greater than 150°, it is considered that the surface of the material has super-hydrophobic or super-oleophobic characteristics. The experimental results show that the SiO2-TiO2-BDBA-PFDTES coating film has a strong repellency to water, and the water droplets are difficult to spread on the surface of the coating film, showing a nearly spherical shape, which indicates that the coating film has super-hydrophobic characteristics. The coating film also has good repellency to diiodomethane, that is, the coating film has super-oleophobic characteristics. Combined with the previous analysis of the microstructure (micro / nano structure) and element composition (containing fluorine elements that reduce the surface energy) of the coating film, the super-hydrophobic and super-oleophobic characteristics are the result of the combined action of the microstructure and chemical composition of the coating film. The micro / nano structure can trap air and reduce the actual contact area between the liquid and the surface of the coating film; and the fluorine elements introduced by PFDTES reduce the surface energy of the coating film. The synergistic effect of the two makes the coating film show good repellency to water and oil, verifying that the SiO2-TiO2-BDBA-PFDTES coating film has good super-biphobic performance.

[0059] Referring to the attached Figure 5 , the dynamic contact process of water and diiodomethane on the SiO2-TiO2-BDBA-PFDTES coating film, when water and diiodomethane contact the surface of the coating film and are pulled up, it is found that water and diiodomethane do not drop on the SiO2-TiO2-BDBA-PFDTES coating film, but are separated from the surface of the coating film along with the pulling of the syringe, which directly indicates that the adhesion between water and diiodomethane and the coating film is small. Further verifying that the SiO2-TiO2-BDBA-PFDTES coating film of the present application has good super-biphobic performance and low adhesion characteristics.

[0060] Referring to the attached Figure 6 , two aluminum sheets are prepared, one of which is coated with a SiO2-TiO2-BDBA-PFDTES coating film, and the other is a pure aluminum sheet as a comparative sample. The aluminum sheet coated with the coating film and the pure aluminum sheet are carefully immersed in ink, milk, coffee and red tea and other different liquids with tweezers and other tools. During the immersion process, the immersion speed and angle of the aluminum sheet are kept consistent to ensure that the experimental conditions are the same. After a period of immersion, the aluminum sheet is taken out of the liquid, and the contamination of the surface of the aluminum sheet is observed and recorded. From the attached Figure 6 results, it can be seen that the pure aluminum sheet is contaminated (colored) by ink, milk, coffee and red tea, showing the corresponding color and stain marks; while the aluminum sheet coated with the SiO2-TiO2-BDBA-PFDTES coating film remains clean (no color), and is not contaminated by the liquid, indicating that the coating film on the aluminum sheet has good anti-fouling performance.

[0061] See the attached Figure 7 The contact angle changes of water and diiodomethane on the SiO2-TiO2-BDBA-PFDTES coating film prepared in this embodiment after immersion in acidic solution (pH = 1) and alkaline solution (pH = 14) for different times (0-140 h) are shown in Figures 1 and 2, respectively. It can be seen from the figures that after acid and alkali treatment for up to 140 h, the contact angles of water and diiodomethane on the coating film remain at a high level (more than 150°), which indicates that this embodiment still has the super-amphiphobic property in the acid and alkali environment, and that the coating film has good resistance to acid and alkali environment. It embodies the stability and reliability of the SiO2-TiO2-BDBA-PFDTES coating film in complex chemical environment. In actual application, in industrial environments or outdoor scenes that may come into contact with acid and alkali substances, the coating film can maintain its super-amphiphobic property for a long time, effectively preventing liquid pollution and erosion, and has high practical value.

[0062] See the attached Figure 8 The contact angle changes of water and diiodomethane on the SiO2-TiO2-BDBA-PFDTES coating film prepared in this embodiment after immersion in a solution with pH = 14 for 140 h and after different numbers (0-4 times) of 2 h heating repair process at 30℃ are shown in Figures 3 and 4. It can be seen that with the increase of the number of repair, the contact angles of water and diiodomethane show certain fluctuation changes, but overall maintain at a high level, which indicates that the heating repair process plays a positive role in the recovery of the super-amphiphobic property of the coating film. Heating accelerates the reformation of borate ester bonds, promotes the migration of long fluorocarbon chains inside the coating film to the surface of the coating film, and long fluorocarbon chains have low surface energy, which supplements the low surface energy segments missing on the surface of the coating film, repairs the damaged surface structure, and thus improves the surface properties of the coating film, which helps to restore the super-amphiphobicity of the coating film. After multiple heating repairs, the coating film can restore its super-amphiphobicity, which indicates that the coating film has a certain self-repairing ability. This property makes the coating film able to restore its performance through simple heating treatment after being damaged by the external environment, prolongs the service life of the coating film, and increases its reliability and practicality in actual application, for example, it has better application prospects in industrial scenes that are easily eroded by chemicals or mechanically damaged.

[0063] See the attached Figure 9 The self-repairing photos of the coating film under the fluorescence microscope after lightly scratching the surface of the coating film with a scalpel and then heating the coating film in an oven at 30℃ are shown in Figures 5 and 6, and the photos of the coating film before and after the self-repairing process are shown in Figures 7 and 8, respectively. It can be seen that after the self-repairing process, the coating film has a smooth and uniform surface, and the surface structure is restored, which indicates that the coating film has a certain self-repairing ability. This property makes the coating film able to restore its performance through simple heating treatment after being damaged by the external environment, prolongs the service life of the coating film, and increases its reliability and practicality in actual application, for example, it has better application prospects in industrial scenes that are easily eroded by chemicals or mechanically damaged. Figure 9The results show that the scratch on the surface of the coating film basically disappears after self-repairing for 2 hours, which indicates that the SiO2-TiO2-BDBA-PFDTES coating film in this embodiment exhibits good self-repairing performance in a heated environment and can effectively repair the surface mechanical damage; mainly because the heating promotes the reformation of the broken borate ester bond, the borate ester bond has a certain dynamic reversibility, under suitable temperature conditions, the broken borate ester bond can be reconnected, thereby repairing the damaged chemical bond structure in the coating film, which is an important chemical basis for the self-repairing of the coating film; the heating enhances the flowability of the polymer. At a higher temperature, the movement ability of the polymer molecular chain increases, so that the molecules can move and rearrange more easily, which helps to fill the damaged parts such as scratches and promotes the self-repairing process; the rapid migration of long fluorocarbon chains promotes the formation of molecular chains. The long fluorocarbon chains have lower surface energy and better migration, under heating conditions, they can migrate to the damaged area more quickly and participate in the reconstruction of the molecular chains, further improving the self-repairing efficiency of the coating film.

[0064] In summary, the SiO2-TiO2-BDBA-PFDTES coating film obtained in Example 1 has good self-repairing performance, which makes it have greater advantages in practical application. In the case of being easily subjected to mechanical wear or scratching, the coating film can realize self-repairing through simple heating treatment, prolong the service life of the coating film, reduce the maintenance and replacement cost, and broaden the application prospect in the fields of industrial protection, electronic device surface coating and the like.

[0065] Example 2

[0066] The present embodiment provides a kind of anticorrosion self-repairing super double repellent coating film, and the specific preparation method of the anticorrosion self-repairing super double repellent coating film is as follows:

[0067] (1) substrate treatment

[0068] After polishing the aluminum sheet, it is cleaned with acetone, anhydrous ethanol and deionized water respectively, and dried with nitrogen. The aluminum sheet is placed in a mixed solution (5 mL of 0.2 mol / L CuSO4 solution and 5 mL of 3 mol / L NaCl solution) for chemical etching for 2 minutes, and then ultrasonically cleaned with deionized water and dried with N2. The aluminum sheet is placed in a 96 ℃ deionized water constant temperature water bath for heating for 4 min, then cleaned with anhydrous ethanol and dried in a 100 ℃ oven;

[0069] (2) synthesis of SiO2-TiO2 composite nanoparticles

[0070] Into a round bottom flask, 10 mL of anhydrous ethanol and 6 mL of ammonia water were added, and 2 mL of tetraethyl orthosilicate (TEOS) was added dropwise under slow stirring. A white SiO2emulsion was obtained by sol-gel method under magnetic stirring at 30 °C for 4 h. 8 mL of SiO2emulsion was added to 1 mL of butyl titanate (TBOT), and ultrasonic dispersion was performed for 10 min. Then, the SiO2-TiO2emulsion was obtained by hydrolysis and polycondensation of the -OH on the surface of SiO2particles under magnetic stirring at 20 °C for 11 h. Centrifugal separation and oven drying at 100 °C were performed to obtain SiO2-TiO2composite nanoparticles.

[0071] (3) Synthesis of SiO2-TiO2-BDBA emulsion

[0072] Into a round bottom flask, 0.2 g of SiO2-TiO2composite nanoparticles and 20 mL of ethanol were added, and ultrasonic stirring was performed for 40 min. Then, 75 mg of 1,4-phenyldiboronic acid (BDBA) and 0.2 mL of ammonia water were added at 25 °C, and magnetic stirring was performed for 6 h to obtain the SiO2-TiO2-BDBA emulsion.

[0073] (4) Synthesis of SiO2-TiO2-BDBA-PFDTES emulsion

[0074] Into a round bottom flask, 6 mL of SiO2-TiO2-BDBA emulsion was added, and 12 mL of ethanol and 1 mL of 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) were added in sequence. The SiO2-TiO2-BDBA-PFDTES emulsion was obtained by reaction at 72 °C for 6 h.

[0075] (5) Coating spraying and curing

[0076] Under a gas pressure of 0.2 Mpa, the SiO2-TiO2-BDBA-PFDTES emulsion was sprayed on an aluminum sheet by a spray gun with a nozzle diameter of 0.3 mm. The SiO2-TiO2-BDBA-PFDTES coating film was obtained by curing in a drying oven at 65 °C for 5 h.

[0077] In this example, SiO2-TiO2 particles are synthesized by generating TiO2 particles on the surface of SiO2 particles through a sol-gel method. The SiO2-TiO2 particles are reacted with BDBA to generate dynamic borate ester bonds. PFDTES is added to modify the surface of SiO2-TiO2-BDBA particles to prepare SiO2-TiO2-BDBA-PFDTES coating. The surface of the coating has a dense and continuous particle distribution. The contact angles of water and diiodomethane on the coating are 167.32° and 154.36°, respectively. In the adhesion test, water and diiodomethane do not drip on the surface of the coating when pulled upwards, indicating that water and diiodomethane have a small adhesion to the coating. After soaking the coating in an acidic solution (pH = 1) for 140 hours, the contact angles of water and diiodomethane are 161.56° and 151.43°, respectively. After soaking the coating in an alkaline solution (pH = 14) for 140 hours, the contact angles of water and diiodomethane are 159.57° and 151.68°, respectively. The coating can self-repair at 30°C for 2 hours.

[0078] Example 3

[0079] This example provides a corrosion-resistant self-repairing super-amphiphobic coating. The specific preparation method is as follows:

[0080] (1) Substrate treatment

[0081] After polishing and polishing the aluminum sheet, it is ultrasonically cleaned with acetone, anhydrous ethanol and deionized water, and dried with nitrogen. The aluminum sheet is placed in a mixed solution (5 mL of 0.2 mol / L CuSO4 solution and 5 mL of 3 mol / L NaCl solution) for chemical etching for 2 minutes, ultrasonically cleaned with deionized water, and dried with N2. The aluminum sheet is placed in a 96 ℃ deionized water constant temperature water bath for heating for 3 min, and then cleaned with anhydrous ethanol and dried in a 100 ℃ oven;

[0082] (2) Synthesis of SiO2-TiO2 composite nanoparticles

[0083] Add 13 mL of anhydrous ethanol and 9 mL of ammonia water to a round-bottom flask, and slowly stir 2 mL of tetraethyl orthosilicate (TEOS) into it. A white SiO2 emulsion is obtained by sol-gel method under magnetic stirring at 26 ℃ for 6 h. Take 8 mL of SiO2 emulsion and add it to 1 mL of butyl titanate (TBOT), ultrasonically disperse for 10 min, and then hydrolyze and polycondensate with the -OH on the surface of SiO2 particles under magnetic stirring at 22 ℃ for 10 h to obtain SiO2-TiO2 emulsion. Centrifugal separation and drying in a 100 ℃ oven give SiO2-TiO2 composite nanoparticles;

[0084] (3) Synthesis of SiO2-TiO2-BDBA emulsion

[0085] In a round bottom flask, 0.2 g of SiO2-TiO2 composite nanoparticles and 20 mL of ethanol were added, and ultrasonic stirring was performed for 40 min. 85 mg of 1,4-benzene diboronic acid (BDBA) and 0.2 mL of ammonia were added at 26°C, and magnetic stirring was performed for 6 h to obtain a SiO2-TiO2-BDBA emulsion.

[0086] (4) Synthesis of SiO2-TiO2-BDBA-PFDTES emulsion

[0087] 5 mL of SiO2-TiO2-BDBA emulsion was added to a round bottom flask, and 10 mL of ethanol and 1 mL of 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) were sequentially added. The reaction was performed at 73°C for 6 h to obtain a SiO2-TiO2-BDBA-PFDTES emulsion.

[0088] (5) Coating spraying and curing

[0089] The SiO2-TiO2-BDBA-PFDTES emulsion was sprayed on an aluminum sheet using a spray gun with a nozzle diameter of 0.3 mm at a gas pressure of 0.2 Mpa, and was cured in a drying oven at 73°C for 5 h to obtain a SiO2-TiO2-BDBA-PFDTES coating film.

[0090] In this example, TiO2 particles were generated on the surface of SiO2 particles by a sol-gel method, and SiO2-TiO2 particles were synthesized. The SiO2-TiO2 particles were reacted with BDBA to generate dynamic borate ester bonds, PFDTES was added to modify the surface of the SiO2-TiO2-BDBA particles, and a SiO2-TiO2-BDBA-PFDTES coating film was prepared. The surface particle distribution of the coating film is dense and continuous, and the contact angles of water and diiodomethane on the coating film are 168.47° and 155.69°, respectively. In the adhesion test, water and diiodomethane did not drip on the surface of the coating film when pulled upward, indicating that the adhesion of water and diiodomethane to the coating film is small. After immersion in an acidic solution (pH = 1) for 140 hours, the contact angles of water and diiodomethane on the coating film were 163.52° and 152.46°, respectively. After immersion in an alkaline solution (pH = 14) for 140 hours, the contact angles of water and diiodomethane on the coating film were 161.73° and 151.12°, respectively. The coating film can be self-repaired by heating at 30°C for 2 hours.

[0091] Example 4

[0092] This example provides a corrosion-resistant self-repairing super-amphiphobic coating film, and the specific preparation method is as follows:

[0093] (1) Substrate treatment

[0094] The aluminum sheet was polished and polished, and then cleaned with acetone, anhydrous ethanol and deionized water under ultrasonic wave, and dried with nitrogen. The aluminum sheet was placed in a mixed solution (5 mL of 0.2 mol / L CuSO4 solution and 5 mL of 3 mol / L NaCl solution) for chemical etching for 2 minutes, and then cleaned with deionized water under ultrasonic wave and dried with N2. The aluminum sheet was placed in a 95 ℃ deionized water constant temperature water bath for heating for 4 min, and then cleaned with anhydrous ethanol and dried in a 100 ℃ oven;

[0095] (2) Synthesis of SiO2-TiO2 composite nanoparticles

[0096] 12 mL of anhydrous ethanol and 8 mL of ammonia water were added to a round-bottom flask, and 2 mL of tetraethyl orthosilicate (TEOS) was slowly added under stirring. A white SiO2 emulsion was obtained by sol-gel method under magnetic stirring at 24 ℃ for 6 h. 9 mL of SiO2 emulsion was taken and added to 1 mL of butyl titanate (TBOT), and ultrasonic dispersion was performed for 10 min. SiO2-TiO2 emulsion was obtained by hydrolysis and polycondensation of -OH on the surface of SiO2 particles under magnetic stirring at 26 ℃ for 10 h. Centrifugal separation and drying in a 100 ℃ oven were performed to obtain SiO2-TiO2 composite nanoparticles;

[0097] (3) Synthesis of SiO2-TiO2-BDBA emulsion

[0098] 0.2 g of SiO2-TiO2 composite nanoparticles and 20 mL of ethanol were added to a round-bottom flask, and ultrasonic stirring was performed for 40 min. 78 mg of 1,4-phenyldiboronic acid (BDBA) and 0.2 mL of ammonia water were added under magnetic stirring at 26 ℃ for 5 h to obtain SiO2-TiO2-BDBA emulsion;

[0099] (4) Synthesis of SiO2-TiO2-BDBA-PFDTES emulsion

[0100] 5 mL of SiO2-TiO2-BDBA emulsion was added to a round-bottom flask, and 10 mL of ethanol and 1 mL of 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) were added in sequence. SiO2-TiO2-BDBA-PFDTES emulsion was obtained by reaction at 70 ℃ for 6 h;

[0101] (5) Coating spraying and curing

[0102] SiO2-TiO2-BDBA-PFDTES emulsion was sprayed on the aluminum sheet by using a spray gun with a nozzle diameter of 0.3 mm under a gas pressure of 0.2 Mpa, and cured in a drying box at 70 ℃ for 4 h to obtain SiO2-TiO2-BDBA-PFDTES coating film.

[0103] In this example, SiO2-TiO2 particles are synthesized by generating TiO2 particles on the surface of SiO2 particles through a sol-gel method. The SiO2-TiO2 particles are reacted with BDBA to generate dynamic borate ester bonds. PFDTES is added to modify the surface of SiO2-TiO2-BDBA particles, and SiO2-TiO2-BDBA-PFDTES coating is prepared. The surface particle distribution of the coating is dense and continuous, and the contact angles of water and diiodomethane on the coating are 159.68° and 151.08°, respectively. In the adhesion test, water and diiodomethane do not drip on the surface of the coating when pulled upward, indicating that water and diiodomethane have a small adhesion to the coating. After soaking in an acidic solution (pH = 1) for 140 hours, the contact angles of water and diiodomethane are 158.45° and 150.76°, respectively. After soaking in an alkaline solution (pH = 14) for 140 hours, the contact angles of water and diiodomethane are 157.96° and 150.42°, respectively. The coating can be self-repaired by heating at 30°C for 2 hours.

[0104] Example 5

[0105] This example provides a corrosion-resistant self-repairing super-amphiphobic coating, and the specific preparation method is as follows:

[0106] (1) Substrate treatment

[0107] After polishing and polishing, the aluminum sheet is ultrasonically cleaned with acetone, anhydrous ethanol and deionized water, and dried with nitrogen. The aluminum sheet is placed in a mixed solution (5 mL of 0.2 mol / L CuSO4 solution and 5 mL of 3 mol / L NaCl solution) for chemical etching for 2 minutes, ultrasonically cleaned with deionized water, and dried with N2. The aluminum sheet is placed in a 96 ℃ deionized water constant temperature water bath for heating for 5 min, and then cleaned with anhydrous ethanol and dried in a 100 ℃ oven;

[0108] (2) Synthesis of SiO2-TiO2 composite nanoparticles

[0109] 12 mL of anhydrous ethanol and 8 mL of ammonia water are added to a round-bottom flask, and 2 mL of tetraethyl orthosilicate (TEOS) is slowly added under stirring. A white SiO2 emulsion is obtained by sol-gel method at 25 ℃ for 6 h. Take 10 mL of SiO2 emulsion, add 1 mL of butyl titanate (TBOT), and ultrasonically disperse for 10 min. Then, the SiO2-TiO2 emulsion is obtained by hydrolysis and polycondensation of -OH on the surface of SiO2 particles under magnetic stirring at 25 ℃ for 11 h. Centrifugal separation and drying in a 100 ℃ oven give SiO2-TiO2 composite nanoparticles;

[0110] (3) Synthesis of SiO2-TiO2-BDBA emulsion

[0111] In a round bottom flask, 0.22 g SiO2-TiO2 composite nanoparticles and 20 mL ethanol were added, and ultrasonic stirring was performed for 40 min. 80 mg of 1,4-benzene diboronic acid (BDBA) and 0.2 mL of ammonia were added at 26 ℃, and magnetic stirring was performed for 5 h to obtain a SiO2-TiO2-BDBA emulsion;

[0112] (4) Synthesis of SiO2-TiO2-BDBA-PFDTES emulsion

[0113] 6 mL of SiO2-TiO2-BDBA emulsion was added to a round bottom flask, and 12 mL of ethanol and 1 mL of 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) were sequentially added. The reaction was performed at 75 ℃ for 6 h to obtain a SiO2-TiO2-BDBA-PFDTES emulsion.

[0114] (5) Coating spraying and curing

[0115] The SiO2-TiO2-BDBA-PFDTES emulsion was sprayed on an aluminum sheet using a spray gun with a nozzle diameter of 0.3 mm at a gas pressure of 0.2 Mpa, and was cured in a drying oven at 70 ℃ for 4 h to obtain an anti-corrosion self-repairing super-amphiphobic SiO2-TiO2-BDBA-PFDTES coating film.

[0116] In this example, TiO2 particles were generated on the surface of SiO2 particles by a sol-gel method, and SiO2-TiO2 particles were synthesized. The SiO2-TiO2 particles were reacted with BDBA to generate dynamic borate ester bonds, PFDTES was added to modify the surface of SiO2-TiO2-BDBA particles, and a SiO2-TiO2-BDBA-PFDTES coating film was prepared. The surface particle distribution of the coating film is dense and continuous, and the contact angles of water and diiodomethane on the coating film are 161.08° and 153.57°, respectively. In the adhesion test, water and diiodomethane did not drip on the surface of the coating film when pulled upward, indicating that water and diiodomethane have small adhesion to the coating film. After immersion in an acidic solution (pH = 1) for 140 hours, the contact angles of water and diiodomethane on the coating film were 159.28° and 151.46°, respectively. After immersion in an alkaline solution (pH = 14) for 140 hours, the contact angles of water and diiodomethane on the coating film were 158.32° and 151.48°, respectively. The coating film can be self-repaired by heating at 30 ℃ for 2 hours.

[0117] The above content only illustrates the technical idea of the present application, and cannot limit the protection scope of the present application. Any modification made according to the technical idea of the present application on the basis of the technical solution falls within the protection scope of the claims of the present application.

Claims

1. An anticorrosive self-repairing omniphobic coating film, characterized by, The corrosion-resistant self-repairing super-amphiphobic coating is composed of a nanoparticle skeleton layer, a dynamic borate bond layer and a super-amphiphobic functional layer from inside to outside; the nanoparticle skeleton layer is composed of SiO2-TiO2 composite nanoparticles; the dynamic borate bond layer is formed on the surface of the SiO2-TiO2 composite nanoparticles by polycondensation reaction of an organic boron compound; and the super-amphiphobic functional layer is grafted on the dynamic borate bond layer by a fluorine-containing organosilicon compound through a silicon-oxygen bond.

2. The anti-corrosion self-repairing omniphobic coating film according to claim 1, characterized in that, The organic boron compound is any one of 1,4-benzenediol, 4,4-biphenyldiboronic acid, 1,3,5-benzenetriol and 1,3-benzenediol.

3. The anti-corrosion self-repairing omniphobic coating film according to claim 1, characterized in that, The fluorine-containing organosilicon compound is any one of 1H,1H,2H,2H-perfluorodecyltriethoxysilane, 1H,1H,2H,2H-perfluorooctyltriethoxysilane, 1H,1H,2H,2H-perfluorodecyltrichlorosilane and trichloro(1H,1H,2H,2H-perfluorooctyl)silane.

4. The anti-corrosion self-repairing omniphobic coating film according to claim 1, characterized in that, The contact angle of the corrosion-resistant self-repairing super-amphiphobic coating is greater than 150°.

5. The preparation method of the anti-corrosion self-repairing omniphobic coating film according to any one of claims 1-4, characterized in that, The method comprises the following steps: Step 1: adding an organic boron compound and ammonia water in a SiO2-TiO2 composite nanoparticle suspension to obtain emulsion 1; Step 2: sequentially adding a fluorine-containing organosilicon compound and ethanol in the emulsion 1 to obtain emulsion 2; Step 3: spraying the emulsion 2 on a pretreated substrate, curing to obtain a corrosion-resistant self-repairing super-amphiphobic coating.

6. The preparation method of the anti-corrosion self-repairing omniphobic coating film according to claim 5, characterized in that, In step 1, the mass ratio of the organic boron compound to the SiO2-TiO2 composite nanoparticles is 1: (2-3), the reaction temperature is 25-30 ℃, and the reaction time is 4-6 h.

7. The preparation method of the anti-corrosion self-repairing omniphobic coating film according to claim 5, characterized in that, In step 1, the SiO2-TiO2 composite nanoparticles are prepared by the following steps: mixing tetraethyl orthosilicate, ammonia water and anhydrous ethanol by sol-gel method to obtain a SiO2 emulsion; adding butyl titanate to assist ultrasonic reaction to obtain a SiO2-TiO2 emulsion, drying to obtain SiO2-TiO2 composite nanoparticles; wherein the particle size of the SiO2-TiO2 composite nanoparticles is 20-100 nm.

8. The preparation method of the anti-corrosion self-repairing omniphobic coating film according to claim 5, characterized in that, In step 2, the volume ratio of the fluorine-containing organosilicon compound, the emulsion 1 and the ethanol is 1: (4-6): (8-12); the reaction temperature is 65-75 ℃, and the reaction time is 5-7 h.

9. The preparation method of the anti-corrosion self-repairing omniphobic coating film according to claim 5, characterized in that, In step 3, the substrate pretreatment is as follows: sequentially ultrasonic cleaning the substrate with acetone, anhydrous ethanol and deionized water, blowing dry with N2, then placing the substrate in a CuSO4 and NaCl mixed solution for chemical etching, blowing dry with N2, then hydrothermal activation, cleaning, and drying.

10. The preparation method of the anti-corrosion self-repairing omniphobic coating film according to claim 9, characterized in that, In the CuSO4 and NaCl mixed solution, the volume ratio of the CuSO4 solution to the NaCl solution is 1: (0.7-1); the hydrothermal activation temperature is 90-100 ℃, and the time is 3-8 min.

Images