Fluorine-free fluorescent super-hydrophobic coating and application thereof

Abstract

The application relates to the technical field of new materials, and discloses a fluorine-free fluorescent super-hydrophobic coating and application thereof, wherein the fluorine-free fluorescent super-hydrophobic coating is fluorine-free hydrophobic SiO2 with fluorescent performance obtained through in-situ modification of porous SiO2; the fluorine-free fluorescent hydrophobic SiO2 is simply sprayed on an etched copper mesh (CM), so that a novel fluorine-free fluorescent super-hydrophobic coating is effectively prepared; the preparation method of the fluorine-free fluorescent hydrophobic SiO2 is simple, low in cost and environment-friendly, can be used for constructing large-scale super-hydrophobic coatings on various substrates, and has universality and practicability; the fluorescent characteristic of the fluorine-free fluorescent hydrophobic SiO2 enables the coating to have a micro-area damage visualization function, and through simple respraying, the super-hydrophobic function of the coating can be repaired. The application opens up a new way for constructing a novel fluorine-free super-hydrophobic fluorescent coating with a micro-damage detection and convenient repair function, and has a wide application prospect in the fields of chemistry, environment and clinical medicine.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new materials, in particular to a fluorine-free fluorescent super-hydrophobic coating and application thereof. BACKGROUND

[0002] Super-hydrophobic coating refers to a coating with extremely strong hydrophobicity, and the water contact angle on the surface thereof is usually greater than 150 degrees. Such coating enables water to present a very high contact angle on the surface thereof, and water droplets will roll in a spherical form from the surface. The super-hydrophobic coating is mainly determined by the combination of the surface micro-nano structure and the hydrophobic material, and the design and preparation of the micro-nano structure can be realized through chemical methods, physical methods or biological methods.

[0003] Super-hydrophobic coating has many potential applications. For example, due to its extremely strong hydrophobicity, super-hydrophobic coating can easily roll and fall off dirt and particles in liquid, thereby realizing self-cleaning effect; super-hydrophobic coating can prevent liquid, dust and dirt from adhering to the surface, keeping the surface clean; super-hydrophobic coating can block liquid from contacting the surface of the substrate, slowing down the corrosion of chemicals; super-hydrophobic coating can prevent moisture from entering to a certain extent, protecting the substrate from moisture; super-hydrophobic coating can be used as surface coating for medical devices to reduce bacterial adhesion while showing good antibacterial performance; super-hydrophobic coating can improve the transparency of lens and glass surface, while reducing water droplet residue in rainy days, improving visual clarity, etc. In addition, most of the current super-hydrophobic coatings are prepared from fluorine-containing silane, which not only has high cost and complex preparation process, but also causes great pollution to the environment due to the wide application of fluorine.

[0004] Therefore, developing a new type of fluorine-free super-hydrophobic coating has a positive promoting effect on the development of various industries.

[0005] At the same time, the super-hydrophobic coating constructed by super-hydrophobic coating will inevitably produce micro-damage in the process of use, which is difficult to be detected but can greatly reduce its super-hydrophobicity. Therefore, developing super-hydrophobic coating with micro-damage detection / repair function for constructing fluorescent super-hydrophobic coating has important significance for expanding its wide application. SUMMARY

[0006] The present application provides a fluorine-free fluorescent super-hydrophobic coating, which is a fluorine-free fluorescent hydrophobic SiO2 obtained by in-situ modification of porous SiO2.

[0007] Further, the preparation method of the porous SiO2 is to dissolve TEA, CTAB and SS in water, then add TEOS, stir at 20-100℃ for 4h, centrifuge, wash and dry the formed solid to obtain the porous SiO2.

[0008] Further, the method for obtaining the fluorine-free fluorescent hydrophobic SiO2 by in-situ modification of the porous SiO2 is as follows:

[0009] The SiO2 is dispersed into long-chain alkyl pyridine (the number of carbon atoms in the alkyl chain is >8) and an alkaline aqueous solution (pH>8), and after reaction, centrifugation, water washing and drying, the fluorine-free fluorescent hydrophobic SiO2 is obtained.

[0010] The application also provides a preparation method of a fluorine-free fluorescent super-hydrophobic coating, wherein any of the fluorine-free fluorescent super-hydrophobic coatings is sprayed on a substrate to obtain the fluorine-free fluorescent super-hydrophobic coating.

[0011] Further, the preparation method of the fluorine-free fluorescent super-hydrophobic material is as follows:

[0012] The fluorine-free fluorescent super-hydrophobic coating is dispersed into an alcohol solution to obtain a fluorine-free fluorescent super-hydrophobic coating-alcohol suspension, and the fluorine-free fluorescent super-hydrophobic coating-alcohol suspension is sprayed on the substrate to obtain the fluorine-free fluorescent super-hydrophobic coating.

[0013] Further, the alcohol solution is methanol, ethanol, ethylene glycol, propylene glycol or the like.

[0014] Further, the fluorine-free fluorescent super-hydrophobic coating-alcohol suspension is sprayed on the copper mesh to obtain the fluorine-free fluorescent super-hydrophobic coating.

[0015] Further, after the spraying is completed, the fluorine-free fluorescent super-hydrophobic material is dried at 30-150°C to obtain the fluorine-free fluorescent super-hydrophobic coating.

[0016] Further, the substrate is an etched copper mesh with micro-nano structures.

[0017] The application also provides an application of the fluorine-free fluorescent super-hydrophobic coating according to any of the application, and the application is to prepare a fluorine-free fluorescent super-hydrophobic coating.

[0018] The application also provides an application of the fluorine-free fluorescent super-hydrophobic material according to any of the application in any of the following aspects:

[0019] ①The application of the fluorine-free fluorescent super-hydrophobic material in oil-water separation;

[0020] ②The application of the fluorine-free fluorescent super-hydrophobic material in preparing an oil-water separation product;

[0021] ③The application of the fluorine-free fluorescent super-hydrophobic material in antibiosis;

[0022] ④The application of the fluorine-free fluorescent super-hydrophobic material in preparing an antibiosis product;

[0023] ⑤The application of the fluorine-free fluorescent super-hydrophobic material in visual micro-damage detection.

[0024] 6. The application of the fluorine-free fluorescent super-hydrophobic material in preparing visual micro-damage detection products;

[0025] 7. The application of the fluorine-free fluorescent super-hydrophobic material in waterproof self-cleaning;

[0026] 8. The application of the fluorine-free fluorescent super-hydrophobic material in preparing waterproof self-cleaning products.

[0027] The application also provides the application of any of the fluorine-free coatings in any of the following:

[0028] 1. The application of the fluorine-free fluorescent super-hydrophobic coating in oil-water separation;

[0029] 2. The application of the fluorine-free fluorescent super-hydrophobic coating in preparing oil-water separation products;

[0030] 3. The application of the fluorine-free fluorescent super-hydrophobic coating in antibiosis;

[0031] 4. The application of the fluorine-free fluorescent super-hydrophobic coating in preparing antibiosis products;

[0032] 5. The application of the fluorine-free fluorescent super-hydrophobic coating in visual micro-damage detection;

[0033] 6. The application of the fluorine-free fluorescent super-hydrophobic coating in preparing visual micro-damage detection products;

[0034] 7. The application of the fluorine-free fluorescent super-hydrophobic coating in waterproof self-cleaning;

[0035] 8. The application of the fluorine-free fluorescent super-hydrophobic coating in preparing waterproof self-cleaning products.

[0036] Compared with the prior art, the application has the beneficial effects that:

[0037] The application provides a fluorine-free fluorescent super-hydrophobic coating and the application thereof.

[0038] The fluorine-free super-hydrophobic fluorescent coating disclosed by the application has excellent fluorescent performance, so that the surface micro-damage has a quick visual identification function, and then can be easily repaired by re-spraying the fluorine-free super-hydrophobic fluorescent coating, and the super-hydrophobicity is not reduced. In addition, the fluorine-free super-hydrophobic fluorescent coating also has good surface robustness (mechanical performance), good chemical / thermal / light stability, antibiosis and self-cleaning performance, so that the fluorine-free super-hydrophobic fluorescent coating is successfully used in oil-water separation, and has high separation efficiency and cycle stability.

[0039] The method for preparing the fluorine-free fluorescent super-hydrophobic coating and the fluorine-free fluorescent super-hydrophobic coating is simple, low in cost, and environmentally friendly, and can be used for constructing large-scale super-hydrophobic coatings on various substrates (aluminum alloy, glass, sponge, fabric, etc.) through simple spraying, and has universality and practicability. The present study opens up a new way for constructing a new type of fluorine-free fluorescent super-hydrophobic coating with micro-damage detection and convenient repair functions, and has wide application prospects in the fields of chemistry, environment, clinical medicine, etc. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 The test result graph for characterizing the porous SiO2, fluorine-free fluorescent super-hydrophobic coating prepared in Example 1, (a) is a preparation schematic diagram of porous SiO2 (d-SiO2) and fluorine-free fluorescent super-hydrophobic SiO2 (fh-SiO2), (b) is an SEM graph thereof, (c) and (d) are TEM images of fh-SiO2, (e) is a fluorescence spectrum of d-SiO2 and fh-SiO2 powders and a fluorescence photo thereof under ultraviolet light irradiation, (f) is an FTIR spectrum of d-SiO2, CDs and fh-SiO2, and (g) is a water contact angle (WCA) of d-SiO2 and fh-SiO2;

[0041] Figure 2 The test result graph for performance research of the fluorine-free fluorescent super-hydrophobic coating prepared in Example 2, wherein (a) is a friction test graph of fh-SiO2 / CM, (b) is a wear test result graph of fh-SiO2 / CM, (c) is a thermal stability test result graph, (c) is a chemical stability test result graph, (d) is a light stability test result graph, (e) is a light stability test result graph, and (f) is a weather resistance test result graph;

[0042] Figure 3 The test result graph of fh-SiO2 / CM for oil-water separation performance and fh-SiO2 / CM for antibacterial performance, wherein (a) is a photo of fh-SiO2 / CM for separating oil / water mixture, (b) is a separation efficiency and oil flux of fh-SiO2 / CM for different oil / water mixtures, (c) is a separation efficiency of fh-SiO2 / CM for four kinds of oil / water mixtures after 20 continuous cycle tests, (d) is a corresponding WCA and WSA of fh-SiO2 / CM after every 5 cycle tests, (e) is a distribution of colonies on culture media of different materials, and (f) is a corresponding bacterial adhesion rate;

[0043] Figure 4The experimental results are shown in the figure for visualization of micro-damage detection and convenient repair research. (a) is a photo of fh-SiO2 / CM after scraping and spraying under sunlight, (b) is a fluorescence photo of it under ultraviolet light, and (c) is the WCAs of fh-SiO2 / CM after scraping-spraying repair.

[0044] Figure 5 The results of the study on the waterproof and self-cleaning properties of fh-SiO2 / CM are shown in the following images: (a) photographs of various food droplets (cola, juice, milk and water) on the surface of fh-SiO2 / CM; (b) photographs of water flow bouncing off the surface of fh-SiO2 / CM; (c) silver mirror phenomenon of fh-SiO2 / CM immersed in water; and (d) self-cleaning process of fh-SiO2 / CM against graphite powder contamination. Detailed Implementation

[0045] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Example 1: Preparation of Fluorescent Superhydrophobic Coating

[0047] Step 1: Preparation of the dendritic SiO2

[0048] 650 mg triethanolamine (TEA), 455 mg hexadecyltrimethylamine bromide (CTAB) and 100 mg sodium salicylate (SS) were dissolved in 20 mL of water and stirred until transparent. Then, 4 mL of tetraethyl orthosilicate (TEOS) was gradually added to the above solution. After stirring at 80 °C for 4 h, the resulting solid was centrifuged and washed three times with water. After drying in a vacuum oven at 60 °C for 4 h, the porous SiO2 was obtained.

[0049] Step 2: Preparation of fluorine-free fluorescent superhydrophobic coating

[0050] 500 mg of the porous SiO2 prepared in step 1 was dispersed in 10 mL of NaOH aqueous solution (1 M), and 10 mL of hexadecylpyridine chloride (CPC) aqueous solution was added under continuous stirring. After reacting at room temperature for 6 h, the obtained solid was centrifuged and washed three times with water. After vacuum drying at 60 °C for 4 h, the fluorescent hydrophobic SiO2, i.e. the fluorine-free fluorescent superhydrophobic coating, was obtained.

[0051] Example 2: Preparation of a fluorine-free fluorescent superhydrophobic coating

[0052] Step 1: Substrate Preparation

[0053] The copper mesh was ultrasonically treated sequentially in acetone, ethanol, deionized water, and 0.1M hydrochloric acid for 15 minutes each to remove organic impurities and the surface oxide layer. The cleaned copper mesh was then immersed in a mixed solution of 66.5mM (NH3)2S2O8 and 1.33M NaOH for 5 minutes at room temperature (approximately 22°C), followed by drying in air at 40°C for 2 hours to obtain an etched copper mesh with a micro / nano structure.

[0054] Step 2: Pretreatment of fluorine-free fluorescent superhydrophobic coating

[0055] 100 mg of the fluorine-free fluorescent superhydrophobic coating solid was added to 5 mL of ethanol solution to obtain a fluorine-free fluorescent superhydrophobic coating-ethanol suspension.

[0056] Step 3: Preparation of fluorine-free fluorescent superhydrophobic coating

[0057] At room temperature, a fluorine-free fluorescent superhydrophobic coating-ethanol suspension was sprayed onto the etched copper mesh with micro / nano structures obtained in step 1 using a spray gun (HD130). During the spraying process, the distance from the nozzle tip of the spray gun to the etched copper mesh was 15 cm, and the spraying time was 30 s. Subsequently, the sprayed etched copper mesh was dried in air at 40°C for 2 hours to obtain the fluorine-free fluorescent superhydrophobic coating.

[0058] Example 3

[0059] The porous SiO2 (hereinafter referred to as d-SiO2) and the fluorine-free fluorescent superhydrophobic coating (hereinafter referred to as fh-SiO2) prepared in Example 1 were characterized.

[0060] Figure 1 (a) in the diagram is a schematic diagram of the preparation process of d-SiO2 and fh-SiO2.

[0061] The morphology of the fh-SiO2 was characterized using field emission scanning electron microscopy (SEM, Nova NanoSEM450, FEI, USA). The results are as follows: Figure 1 As shown in b, the results show that fh-SiO2 has a distinct porous structure with an average size of 175 nm.

[0062] The fh-SiO2 was characterized using transmission electron microscopy (TEM, Tecnai G2F20STWIN, USA). The results are as follows: Figure 1 As shown in c and d, the results also reveal its porous structure and uniform size distribution. This indicates the successful synthesis of d-SiO2, which provides the necessary micro / nano structure for constructing superhydrophobic coatings.

[0063] The fluorescence spectra of the d-SiO2 and fh-SiO2 were measured using a fluorescence spectrometer.Figure 1 eThe pictures of fh-SiO2 and d-SiO2 powders under UV light (365 nm) irradiation are shown in the inset. It can be seen that fh-SiO2 powder can emit bright yellow fluorescence under UV light irradiation, while d-SiO2 has no fluorescence. The yellow fluorescence of fh-SiO2 should come from the CDs generated on the surface of d-SiO2 nanoparticles. Figure 1 eThe fluorescence spectra of fh-SiO2 and d-SiO2 (dispersed in ethanol) are shown, respectively. It can be seen that the fluorescence maximum emission wavelength of fh-SiO2 is at 534 nm, while d-SiO2 has no fluorescence emission in the wavelength range of 350 nm to 700 nm. These results further prove that the synthesized fh-SiO2 has excellent fluorescence performance.

[0064] The surface functional groups and crystal structure of d-SiO2 and fh-SiO2 were tested using a Fourier transform infrared spectrometer (FTIR). The results are shown in Figure 1 fCompared with d-SiO2 and CDs, fh-SiO2 has strong absorption peaks at 2920 cm -1 and 2850 cm -1 , which should be attributed to the stretching vibration of C-H on long alkyl chains. The absorption peak at 1465 cm -1 is attributed to the shear vibration of -CH2, and the absorption peak at 720 cm -1 is attributed to the in-plane swing vibration of long carbon alkyl chain -(CH2) n (n > 4). These results all indicate that there are long alkyl chains on the surface of fh-SiO2, which makes fh-SiO2 hydrophobic.

[0065] To prove this result, the water contact angle (WCA) of d-SiO2 and fh-SiO2 was measured using a contact angle measuring instrument (DSA30). The results are shown in Figure 1 gThe WCA of fh-SiO2 was measured to be 158.6°, which is much higher than that of d-SiO2, which is 28.4°, indicating that the presence of CDs on SiO2 can make fh-SiO2 have excellent superhydrophobicity.

[0066] Example 4

[0067] The performance of the fluorine-free fluorescent superhydrophobic coating (hereinafter referred to as fh-SiO2 / CM) prepared in Example 2 was studied.

[0068] Figure 2 aThe schematic diagram of the mechanical strength test of fh-SiO2 / CM.

[0069] The fh-SiO2 / CM prepared was contacted with 180 mesh sandpaper and subjected to sandpaper abrasion test to evaluate the mechanical strength of fh-SiO2 / CM. fh-SiO2 / CM was moved horizontally for 10 cm (defined as one cycle) under 50 g external load, and the WCA and water sliding angle (WSA) of fh-SiO2 / CM were measured before and after each abrasion test. The results are shown in Figure 2 b. The WCA of fh-SiO2 / CM only slightly decreased from 159.5° to 151.9° after 10 consecutive test cycles, and the corresponding WSA increased from 3.6° to 8.8°, which still remained superhydrophobic after the test, indicating that fh-SiO2 / CM has good mechanical stability.

[0070] The high temperature resistance of the fluorine-free superhydrophobic coating was evaluated according to the WCA and WSA of fh-SiO2 / CM after heating at different temperatures for 2 h. The results are shown in Figure 2 c. The WCA of fh-SiO2 / CM remained above 150° and the WSA remained below 10° even after heat treatment at a higher temperature of 180 °C for 2 h, indicating that fh-SiO2 / CM has good thermal stability and can be used in a wide temperature range.

[0071] The chemical stability of fh-SiO2 / CM was evaluated by immersing fh-SiO2 / CM in NaCl (3.5%) solutions with different pH values (12 h) and then measuring its WCA and WSA. The results are shown in Figure 2 d. The results show that the WCA remained above 150° and the WSA remained below 10°. fh-SiO2 / CM maintained its good chemical stability even in strongly acidic (pH = 2.0) and alkaline (pH = 12.0) solutions. The higher stability in the strongly acidic solution is due to the excellent superhydrophobicity of the coating, which forms an air film between the coating and the solution effectively preventing H + damage to the coating.

[0072] The UV radiation resistance of fh-SiO2 / CM was evaluated by continuously irradiating fh-SiO2 / CM under a UV lamp (6 W) at a distance of 15 cm. The results are shown in Figure 2 e. The WCAs (>153.4°) and WSAs (<6.9°) did not change significantly after 12 h of continuous ultraviolet light (365 nm) irradiation, indicating that fh-SiO2 / CM has good light stability.

[0073] The weather resistance of fh-SiO2 / CM was evaluated by exposing fh-SiO2 / CM to actual outdoor environments for a long period of time, during which fh-SiO2 / CM experienced rainy and sunny days, and the WCA and WSA of fh-SiO2 / CM were measured every 5 days. Figure 2f, the results show that the coating still has good superhydrophobicity (WCA ≈ 151°, WSA ≈ 8°) after 30 days of continuous testing.

[0074] The above experiments prove that the constructed fh-SiO2 / CM has high mechanical strength, good chemical / light / thermal stability and excellent weather resistance, and can be widely used in complex environmental conditions.

[0075] Oil-water separation performance of fh-SiO2 / CM: The prepared fh-SiO2 / CM was fixed between two glass tubes. A series of simple oil / water mixtures were prepared by mixing water and oil (including carbon tetrachloride, dichloromethane, ethyl acetate, cyclohexane) at a volume ratio of 1:1. In the experiment, the water phase and the oil phase were dyed with methylene blue and Sudan I, respectively. After pouring the oil / water mixture into the separation device, separation was carried out under gravity. The oil-water separation efficiency (η) was calculated by equation (1):

[0076]

[0077] Where m0and m1are the masses before and after separation, respectively.

[0078] The oil flux (F) was calculated by equation (2):

[0079]

[0080] Where V is the volume of collected oil, S is the effective surface area of oil separation, and T is the separation time.

[0081] When the oil / water mixture was poured into fh-SiO2 / CM, taking cyclohexane / water as an example, yellow cyclohexane could be collected in the beaker below fh-SiO2 / CM under the action of gravity, while blue water was retained at the top of the grid, as shown in Figure 3 a. After separation, the collected cyclohexane and water were both transparent, indicating that fh-SiO2 / CM had good oil-water separation capacity.

[0082] Figure 3 b shows the separation efficiency of fh-SiO2 / CM for four kinds of oil / water mixtures. From the experimental results, it can be seen that the separation efficiency of the four organic matters is greater than 97%, and the measured oil flux is greater than 16000 Lm -2 h -1 , confirming that fh-SiO2 / CM has high oil / water separation efficiency. Further study was made on the reusability and stability of fh-SiO2 / CM in oil-water separation. As Figure 3As shown in Fig. c, the separation efficiency of fh-SiO2 / CM for the four mixtures can be maintained above 96% after 20 continuous cycles, and its WCA remains above 150.3° and WSA is below 9.2° Figure 3 d). These results show that the fh-SiO2 / CM constructed on the surface of etched copper mesh (e-CM) by a simple spray method has good reusability and stability, which is of great significance for its practical application in oil-water separation.

[0083] Antibacterial performance of fh-SiO2 / CM: The surface of superhydrophobic material prevents the adhesion of bacteria due to its super-repellence to water. The antibacterial performance of the coating was evaluated according to the bacterial adhesion rate E. Escherichia coli and Staphylococcus aureus were selected as representatives of gram-negative and gram-positive bacteria to investigate the antibacterial performance of fh-SiO2 / CM.

[0084] The bacteria were placed in Luria-Bertani (LB) medium and cultured in a constant shaker (37°C, 160 rpm) for 12 h, and the concentration of the bacterial solution was adjusted to 10 7 CFU / mL. The original copper mesh (p-CM), e-CM and fh-SiO2 / CM (2 cm x 2 cm) were sterilized by ultraviolet irradiation for 24 h. 5 mL of bacterial solution was taken, and fh-SiO2 / CM was completely immersed in the solution for 2 h. p-CM and e-CM were used as controls.

[0085] The bacterial adhesion rate E was calculated by formula (3):

[0086]

[0087] Where E is the bacterial adhesion rate, N is the bacterial concentration (Escherichia coli and Staphylococcus aureus), N sample is the bacterial concentration of fh-SiO2 / CM.

[0088] As Figure 3 shown in Fig. e, compared with p-CM and e-CM, it can be seen that no bacteria adhere to fh-SiO2 / CM, because it has stronger superhydrophobicity than p-CM and e-CM.

[0089] Figure 3 Fig. f shows the bacterial adhesion rates of Escherichia coli and Staphylococcus aureus on the surfaces of fh-SiO2 / CM, p-CM and e-CM, respectively. The results show that the adhesion rates of the two bacteria on fh-SiO2 / CM are both less than 0.2%, which is much lower than that of p-CM and e-CM, indicating that fh-SiO2 / CM has excellent antibacterial performance and great advantages in practical application.

[0090] A study on the visualization and convenient repair of fh-SiO2 / CM micro-damage; Although the fh-SiO2 / CM coating has been proven to have excellent mechanical strength, inevitable damage during use, especially micro-damage (too small to be detected), will significantly reduce its superhydrophobicity. In this work, an "X" shape was made on the constructed superhydrophobic coating with a knife, and then fh-SiO2 was sprayed onto the damaged area for repair. Figure 4 As shown in Figure a, the "X" scratch is not visible under sunlight. However, under ultraviolet light (365nm), due to its excellent fluorescence properties, it can be clearly observed with the naked eye. Figure 4 b. After spraying with fh-SiO2, no signs of regeneration were observed under sunlight and ultraviolet radiation, and the damaged areas were completely repaired. The WCAs of fh-SiO2 / CM were also tested accordingly. Figure 4 As shown in Figure c, after damage, its WCA value decreased from 159.1° to 135.5°, indicating that micro-scratches on the coating severely reduce its superhydrophobicity. After recoating, the WCA value of the coating recovered to 159.2°, demonstrating that this simple recoating can restore its original superhydrophobicity. Based on this, we can conclude that the fluorescence of fh-SiO2 / CM endows the coating with the ability to visually detect micro-damage. Combined with convenient repair techniques, this will give superhydrophobic coatings potential applications in many fields.

[0091] Study on the waterproof and self-cleaning properties of fh-SiO2 / CM; antifouling ability is one of the important parameters in the practical application of hydrophobic coatings. Figure 5 Display a series of droplets of various food liquids, including cola, juice, milk, and water (stained with methylene blue), on an fh-SiO2 / CM surface. Their spherical shape indicates weak adhesion to fh-SiO2 / CM, demonstrating its excellent antifouling ability. Furthermore, water flow can bounce off the fh-SiO2 / CM surface, see [image / description]. Figure 5 b, further demonstrating its excellent hydrophobic properties. Immersing fh-SiO2 / CM in water reveals a distinct silver mirror-like phenomenon ( Figure 5 c) This is due to the large amount of air between the grooves in the micro / nanostructures and the water, protecting the coating from water wetting. Furthermore, the self-cleaning ability of fh-SiO2 / CM was tested. From Figure 5 As can be seen from d, the graphite powder on the surface of fh-SiO2 / CM can be completely washed away by water, indicating that it has good self-cleaning properties and has potential application prospects in anti-surface contamination.

[0092] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and that the appended claims are intended to cover all such modifications that do not depart from the true spirit and scope of the application. Therefore, the application is not limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fluorine-free fluorescent superhydrophobic coating, characterized in that, The preparation method of the fluorine-free fluorescent super-hydrophobic coating is as follows: The fluorine-free fluorescent super-hydrophobic coating is obtained by dispersing the fluorine-free fluorescent super-hydrophobic paint into alcohol to obtain a fluorescent super-hydrophobic paint-alcohol suspension, and then spraying the fluorescent super-hydrophobic paint-alcohol suspension on a substrate. The fluorine-free fluorescent super-hydrophobic coating is a fluorescent hydrophobic SiO2 obtained by in-situ carbonization modification of porous SiO2. The preparation method of the porous SiO2 is as follows: triethanolamine, cetyltrimethylammonium bromide and sodium salicylate are dissolved in water, and then tetraethyl orthosilicate is added to obtain the porous SiO2. The method for obtaining the fluorescent hydrophobic SiO2 by in-situ modification of the porous SiO2 is as follows: The fluorine-free fluorescent super-hydrophobic coating is obtained by dispersing the porous SiO2 into cetylpyridinium chloride and reacting in an alkaline aqueous solution to obtain the fluorine-free fluorescent hydrophobic SiO2.

2. The fluorescent superhydrophobic coating according to claim 1, wherein, The fluorine-free fluorescent super-hydrophobic coating is obtained by spraying the fluorescent super-hydrophobic paint-alcohol suspension on a copper mesh, and then naturally drying or drying.

3. The fluorine-free fluorescent superhydrophobic coating according to claim 1, wherein, The substrate is an etched copper mesh with micro-nano structures.

4. The fluorine-free fluorescent super-hydrophobic coating according to any one of claims 1-3 is applied in any one of the following: ① The fluorine-free fluorescent super-hydrophobic coating is applied in oil-water separation; ② The fluorine-free fluorescent super-hydrophobic coating is applied in antibiosis; ③ The fluorine-free fluorescent super-hydrophobic coating is applied in visual micro-damage detection; ④ The fluorine-free fluorescent super-hydrophobic coating is applied in waterproof self-cleaning.

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