Preparation method and application of tungsten oxide-based super-amphiphobic photochromic coating material

Abstract

The present application relates to a kind of tungsten oxide-based super-amphiphobic photochromic coating material preparation method, application, in the preparation process, zinc ion and sodium dodecyl benzene sulfonate are introduced to the morphology of WO3 / ZnO powder is doubly regulated.In the low surface energy treatment of WO3 / ZnO powder after improvement method, finally obtainable reentrant micro / nano structure of flower-like.The prepared super-amphiphobic photochromic coating is blue within 3min under ultraviolet irradiation, fade after heating 90min in air, photochromism obtains great promotion.The contact angle of the coating to water and edible oil is all greater than 150°.In addition, when facing sand impact, water impact, corrosive solution, long-term ultraviolet irradiation, still maintain super-amphiphobicity, and also have antifouling and self-cleaning ability.The present application provides new insights for developing super-amphiphobic photochromic material with good stability and high repeatability, and has good application prospect in the field of optical information storage, anti-fake and rewritable material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of preparation of photochromic coating, and particularly relates to a preparation method and application of a tungsten oxide-based super-amphiphobic photochromic coating material. BACKGROUND

[0002] Due to the over-reliance of society on energy equipment, the reserves of fossil fuels are decreasing and environmental problems are arising, so it is urgent to explore alternative renewable energy. Efficient use of light energy is very important for the development of advanced optical functional materials and the realization of effective use of renewable energy. Therefore, researchers have made great efforts in the fields of photocatalysis, solar energy, and photo-thermal conversion and photochromism. "Photochromism" is defined as a reversible color change caused by light irradiation. More specifically, it refers to the reversible transition of a chemical substance between two forms due to electromagnetic radiation. Among all photochromic materials, tungsten trioxide (WO3) has become one of the most widely studied candidate materials due to its low cost, abundant reserves, highly adjustable composition, good chemical stability at room temperature, higher sensitivity to light, and high electron transport capacity. Compared to the electrochromic performance which requires complex external equipment and power supply, the use of clean energy and non-contact input light-induced approach to impart reversible color conversion to the surface is more attractive. So far, researchers generally believe that the inter-valence electron transfer between different valence states of tungsten ions is the key factor that may cause photochromism. However, the recombination of photo-generated electron-hole pairs can affect the photochromic efficiency. With the rapid development of the field of photochromism, the research focus has shifted from transfer mechanism and band gap to improving photochromic response and performance, which involves the control of material structure and morphology. For single inorganic photochromic substances, they usually exhibit low fatigue and poor reversibility. SUMMARY

[0003] The present application provides a preparation method and application of a tungsten oxide-based super-amphiphobic photochromic coating material. The nano-flower-like ZnO / WO3 powder is prepared by a hydrothermal method and fluorination treatment, and a photochromic coating is formed on the surface of the substrate by a double-sided adhesive assisted deposition method. The coating has low adhesion, heat resistance, corrosion resistance, ultraviolet resistance and wear resistance. Compared with the previous photochromic organic / inorganic dyes, the coating provided by the present application can exhibit coloring and bleaching on the same surface when exposed to ultraviolet light, and can be rewritten multiple times without loss of resolution. The preparation method provided by the present application is simple, green and environmentally friendly, and has high repeatability, which is a reliable solution for preparing super-amphiphobic photochromic materials.

[0004] The solution to the above technical problem is as follows: a preparation method of a tungsten oxide-based super-amphiphobic photochromic coating material, comprising the following steps:

[0005] 1) Dissolve sodium tungstate dihydrate and sodium dodecylbenzenesulfonate in deionized water to obtain solution A. Then add strong acid to adjust the pH of the solution to 1-2 and stir. Dissolve oxalic acid and ammonium sulfate in deionized water to obtain solution B. Mix solution A and solution B and add zinc acetate dihydrate. Continue stirring to obtain precursor solution. Transfer the precursor solution to a reaction vessel. After hydrothermal reaction, centrifuge and dry the product.

[0006] 2) The dried product was immersed in HNO3 solution for acidification, and after centrifugation, drying and grinding, WO3 / ZnO powder was obtained;

[0007] 3) Disperse WO3 / ZnO powder in a mixture of ethanol, ammonia and deionized water (volume ratio of 40:3:3), then add tetraethyl orthosilicate and 1H,1H,2H,2H-perfluorodecyltriethoxysilane. Stir the mixture at room temperature for 8 hours. After centrifugation and drying at 80℃, a superhydrophobic photochromic coating material is obtained.

[0008] Preferably, in step 1), the mass ratio of sodium tungstate dihydrate, zinc acetate dihydrate, and sodium dodecylbenzenesulfonate is 1:0.1 to 1:0.1 to 1.

[0009] Preferably, in step 1), the mass ratio of oxalic acid to ammonium sulfate is 1:0.5 to 10.

[0010] Preferably, in step 1), the hydrothermal reaction temperature is 100–200°C and the reaction time is 1–10 h.

[0011] Further preferred, in step 1), the hydrothermal reaction temperature is 180℃ and the reaction time is 8h.

[0012] Preferably, in step 2), the concentration of the HNO3 solution is 0.01–10 mol / L; and the soaking time is 5–20 h.

[0013] Preferably, in step 3), the ZnO content in the WO3 / ZnO powder is 10-20% by mass.

[0014] Preferably, in step 3), the mass ratio of WO3 / ZnO powder, tetraethyl orthosilicate, and 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane is 1:0.15-0.6:0.2-0.9. More preferably, in step 3), the mass ratio of WO3 / ZnO powder, tetraethyl orthosilicate, and 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane is 1:0.31:0.46; that is, the feed ratio is 0.3g:0.1ml:0.1ml (the density of tetraethyl orthosilicate is 0.933g / ml, and the density of 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane is 1.389g / ml).

[0015] A tungsten oxide-based superomniphobic photochromic coating is formed on a surface of a substrate from the superomniphobic photochromic coating material prepared by the method as described above by an assisted deposition method.

[0016] Preparation of the tungsten oxide-based superomniphobic photochromic coating as described above by a double-sided tape assisted deposition method, comprising the following steps: a double-sided tape is adhered to a substrate, then the superomniphobic photochromic coating material is uniformly coated on the surface of the double-sided tape, pressed, and then the excess material is shaken off to obtain the tungsten oxide-based superomniphobic photochromic coating.

[0017] Application of the tungsten oxide-based superomniphobic photochromic coating as described above in repeated writing under ultraviolet light.

[0018] The present application has the following advantages:

[0019] 1. The superomniphobic photochromic coating prepared by the preparation method has low adhesion, heat liquid resistance, corrosion resistance, ultraviolet resistance and wear resistance, and the contact angles of the surface to water and rapeseed oil are both greater than 150°.

[0020] 2. The superomniphobic photochromic coating prepared by the preparation method can appear coloring and bleaching on the same surface when exposed to ultraviolet light, and can be rewritten multiple times without loss of resolution.

[0021] 3. The preparation method provided by the present application is simple, has high repeatability, and is low in cost.

[0022] 4. The superomniphobic photochromic coating prepared by the preparation method has the characteristics of less pollution, low cost, fast color conversion, mass production and adaptation to harsh environments.

[0023] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, and to implement the content of the description, the following will be described in detail with the preferred embodiments of the present application and the accompanying drawings. The specific embodiments of the present application are described in detail by the following examples and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings described herein are used to provide further understanding of the present application, and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application, and do not constitute an improper limitation on the present application. In the drawings:

[0025] Figure 1 The present application is a tungsten oxide-based superomniphobic photochromic coating material preparation flow chart.

[0026] Figure 2SEM images of various embodiments and comparative examples; a) is the SEM image of the photochromic coating of Comparative Example 2; b) is the SEM image of the photochromic coating of Comparative Example 3; c) is the SEM image of the photochromic coating of Comparative Example 7; d) is the SEM image of the photochromic coating of Comparative Example 8; e) is the SEM image of the photochromic coating of Comparative Example 9; f) is the SEM image of the photochromic coating of Example 3; g) is the SEM image of the photochromic coating of Example 1; h) is the SEM image of the photochromic coating of Example 10; i) is the SEM image of the photochromic coating of Comparative Example 4; g) is the SEM image of the photochromic coating of Comparative Example 5; k) is the SEM image of the photochromic coating of Comparative Example 6; 1) is the SEM image of the photochromic coating of Comparative Example 1; m) is the structural model image of the photochromic coating of Example 1.

[0027] Figure 3 Composition analysis images of various embodiments and comparative examples; a) is the XRD image of the coating material prepared in Example 10, Comparative Example 3, Comparative Example 9, Comparative Example 10; b) is the FTIR image of the coating material prepared in Comparative Example 2, Comparative Example 3, Comparative Example 8, Comparative Example 11, Example 1; c) is the XPS full spectrum image of the coating material prepared in Comparative Example 3, Comparative Example 8, Comparative Example 9, Example 1, Example 10; d) is the W 4f fine spectrum image of Comparative Example 3, Comparative Example 8, Comparative Example 9; e) is the O 1s fine spectrum image of Comparative Example 3, Comparative Example 8, Comparative Example 9; f) is the C 1s fine spectrum image of Example 1; g) is the Zn 2p fine spectrum image of Example 1; h) is the O 1s fine spectrum image of Example 1.

[0028] Figure 4 Contact angles of the photochromic coating of Example 1 under various conditions; a) is the schematic diagram of the surface of the photochromic coating of Example 1 adapting to harsh environments; b) is the schematic diagram of the contact angle and heat resistance of Example 1 to different temperature hydrothermal fluids; c) is the contact angle change diagram of Example 1 irradiated by a 20W intensity ultraviolet lamp (3535-9Z) for 72 hours; d) is the contact angle of Example 1 to liquids with pH = 1 to 14, the silver mirror reaction of the acid with pH = 1, the saturated sodium chloride solution with pH = 7 and the base with pH = 14; e) is the contact angle of Example 1 after water impact test; f) is the contact angle of Example 1 after sand impact test.

[0029] Figure 5Figure 1 : Contact angle and optical photographs of various droplets for each example and comparative example; a) Contact angle of water and oil for example 1, 5, 8, 10 and comparative example 11; b) Contact angle and optical photographs of water and oil for example 1; c) Adhesion test of water and oil for example 1; d) Silver mirror effect of water and oil for example 1; e) Optical photograph of water and oil droplets standing on the surface of example 1 before UV irradiation; f) Optical photograph of water and oil droplets standing on the surface of example 1 after UV irradiation; g) Optical photograph of water droplet bouncing on the surface of example 1; h) Optical photograph of droplet-solid surface contact of ethylene glycol on the surface of example 1; j) Optical photograph of droplet-solid surface contact of liquid paraffin on the surface of example 1; i) Optical photograph of droplet-solid surface contact of glycerol on the surface of example 1; k) Optical photograph of droplet-solid surface contact of rapeseed oil on the surface of example 1.

[0030] Figure 6 Figure 2: Anti-staining performance test of example 1; a) Photograph of example 1 taken after immersion in a methylene blue dyed aqueous solution; b) Photograph of example 1 taken after immersion in a mixture of carbon black and ethylene glycol; c) Photograph of example 1 taken after immersion in rhodamine dyed glycerol; d) Photograph of example 1 taken after immersion in rapeseed oil; e) Photograph of hydrophilic methylene blue powder sliding off the surface of the coating of example 1; f) Photograph of hydrophobic carbon black powder sliding off the surface of the coating of example 1.

[0031] Figure 7 Figure 3: Photochromic phenomenon of the coating of each example and comparative example; a) Photograph of comparative example 6 as it changes colour with UV light irradiation time; b) Photograph of comparative example 8 as it changes colour with UV light irradiation time; c) Photograph of comparative example 1 as it changes colour with UV light irradiation time; d) Photograph of example 1 as it changes colour with UV light irradiation time; e) W 4f XPS fine spectrum of example 1 after colour change; f) DRS spectrum and a h v 1 / 2 vs photon energy graph of comparative example 8; g) DRS spectrum and a h v 1 / 2 vs photon energy graph of example 1

[0032] Figure 8 Figure 4: Fading phenomenon of the coating of example 1 after it has changed colour with UV light irradiation; a) Flowchart of the process of writing with UV light masking and thermal erasing on the surface of the coating of example 1; b) Optical photograph of the coating of example 1 as it is written on with UV light-thermal erasing cycle; c) Photograph of the coating of example 1 as it fades naturally in different environments. DETAILED DESCRIPTION

[0033] The principles and features of the present application are described below in connection with the attached drawings, which are only for the purpose of illustration and not for limiting the scope of the present application.

[0034] The working principle of the present application is that the conduction band and valence band positions of the two semiconductor oxides ZnO and WO3 are different, and the effective transfer of charge carriers and photo-generated holes between the composite semiconductor levels delays the recombination of electrons and holes, thereby obtaining higher photochromic performance. By improving the low surface energy treatment of WO3 / ZnO powder, the roughness of the surface of the WO3 / ZnO powder is improved by hydrophobic molecules, which can significantly improve the stability of the photochromic material, and endow the photochromic material with self-cleaning and super-humidity resistance.

[0035] Example 1

[0036] As Figure 1 shown, the present embodiment 1 provides a preparation method of a tungsten oxide-based super-biphobic photochromic coating (denoted as FWZ-16%), which comprises the following steps:

[0037] 1. Dissolve 2.8 g of sodium tungstate dihydrate and 0.8 g of sodium dodecylbenzenesulfonate in 20 ml of deionized water, adjust the pH of the solution to 1 with 6 mol / L HCl, and stir for 30 min. At the same time, dissolve 2.52 g of oxalic acid and 5.28 g of ammonium sulfate in 30 ml of deionized water.

[0038] 2. Mix the two solutions and add 0.65 g of zinc acetate dihydrate, continue stirring for 1 h. Then, transfer the mixed solution to a stainless steel autoclave and react at 180℃ for 8 h, then centrifuge.

[0039] 3. After vacuum drying at 80℃ for 6 h, immerse the dried product in 4 mol / L HNO3 for 12 h, then centrifuge and vacuum dry. Grind the dried product to obtain WO3 / ZnO powder.

[0040] 4. Disperse 0.3 g of WO3 / ZnO powder in 80 ml of ethanol, 6 ml of ammonia water and 6 ml of deionized water, and stir vigorously at room temperature for 30 min. Then, add 100 μl of tetraethyl orthosilicate and 100 μl of 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane to the suspension, and centrifuge after 8 h of reaction. Dry at 80℃ to obtain FWZ super-biphobic powder.

[0041] 5. Stick double-sided tape on a glass plate, then evenly coat the FWZ super-biphobic powder on the surface. Gently press and shake off the excess powder to obtain a tungsten oxide-based super-biphobic photochromic coating.

[0042] Example 2

[0043] The embodiment provides a preparation method of a tungsten oxide-based super-biphobic photochromic coating (denoted as FWZ-10%).

[0044] Example 3

[0045] The embodiment provides a preparation method of a tungsten oxide-based super-biphobic photochromic coating (denoted as FWZ-12%).

[0046] Example 4

[0047] The embodiment provides a preparation method of a tungsten oxide-based super-biphobic photochromic coating (denoted as FWZ-13%).

[0048] Example 5

[0049] The embodiment provides a preparation method of a tungsten oxide-based super-biphobic photochromic coating (denoted as FWZ-14%).

[0050] Example 6

[0051] The embodiment provides a preparation method of a tungsten oxide-based super-biphobic photochromic coating (denoted as FWZ-15%).

[0052] Example 7

[0053] The embodiment provides a preparation method of a tungsten oxide-based super-biphobic photochromic coating (denoted as FWZ-17%).

[0054] Example 8

[0055] The embodiment provides a preparation method of a tungsten oxide-based super-biphobic photochromic coating (denoted as FWZ-18%).

[0056] Example 9

[0057] The present example provides a preparation method of a tungsten oxide-based super-dual-wettability photochromic coating (denoted as FWZ-19%). The steps are basically the same as those of Example 1, except that in step 2, the mass of zinc acetate dihydrate added is 0.80 g.

[0058] Example 10

[0059] The present example provides a preparation method of a tungsten oxide-based super-dual-wettability photochromic coating (denoted as FWZ-20%). The steps are basically the same as those of Example 1, except that in step 2, the mass of zinc acetate dihydrate added is 0.85 g.

[0060] Comparative Example 1

[0061] The present comparative example provides a preparation method of a tungsten oxide-based super-dual-wettability photochromic coating (denoted as NFWZ-16%). The steps are basically the same as those of Example 1, except that in step 1, no sodium dodecyl benzene sulfonate is added.

[0062] Comparative Example 2

[0063] The present comparative example provides a preparation method of a photochromic coating (denoted as PZnO). The steps are basically the same as those of Example 1, except that in step 1, no sodium tungstate dihydrate is added; and no step 4 treatment is performed.

[0064] Comparative Example 3

[0065] The present comparative example provides a preparation method of a photochromic coating (denoted as PWO3). The steps are basically the same as those of Example 1, except that in step 2, no zinc acetate dihydrate is added; and no step 4 treatment is performed.

[0066] Comparative Example 4

[0067] The present comparative example provides a preparation method of a photochromic coating (denoted as NPWO3). The steps are basically the same as those of Example 1, except that in step 1, no sodium dodecyl benzene sulfonate is added; in step 2, no zinc acetate dihydrate is added; and no step 4 treatment is performed.

[0068] Comparative Example 5

[0069] The present comparative example provides a preparation method of a photochromic coating (denoted as NFPWO3). The steps are basically the same as those of Example 1, except that in step 1, no sodium dodecyl benzene sulfonate is added; in step 2, no zinc acetate dihydrate is added.

[0070] Comparative Example 6

[0071] This comparative example provides a method for preparing a photochromic coating (denoted as NWZ-16%) which is substantially the same as that of Example 1, except that in Step 1, no sodium dodecyl benzene sulfonate is added; and no Step 4 treatment is performed.

[0072] Comparative Example 7

[0073] This comparative example provides a method for preparing a photochromic coating (denoted as WZ-12%) which is substantially the same as that of Example 3, except that no Step 4 treatment is performed.

[0074] Comparative Example 8

[0075] This comparative example provides a method for preparing a photochromic coating (denoted as WZ-16%) which is substantially the same as that of Example 1, except that no Step 4 treatment is performed.

[0076] Comparative Example 9

[0077] This comparative example provides a method for preparing a photochromic coating (denoted as WZ-20%) which is substantially the same as that of Example 10, except that no Step 4 treatment is performed.

[0078] Comparative Example 10

[0079] This comparative example provides a method for preparing a photochromic coating (denoted as NWZ-20%) which is substantially the same as that of Example 10, except that in Step 1, no sodium dodecyl benzene sulfonate is added; and no Step 4 treatment is performed.

[0080] Comparative Example 11

[0081] This comparative example provides a method for preparing a photochromic coating (denoted as FWZ-0%) which is substantially the same as that of Example 1, except that in Step 2, no zinc acetate dihydrate is added.

[0082] The morphology of each example and comparative example was observed by electron microscopy, as shown in Figure 2 Fig. 2, the photochromic coating of Comparative Example 2 (denoted as PZnO) was not treated by hydrophobization, and was short nanorod-like Figure 2 (a), the photochromic coating of Comparative Example 3 (denoted as PWO3) was free of Zn 2+ , and was nanoneedle-like Figure 2 (b). Comparative Example 6 was compared with Comparative Example 7 and Comparative Example 8, and when Zn 2+ was present in the solution, the nanoneedles in the sample were observed to grow in a radial direction Figure 2 (c- Figure 2 (e). 2+As the concentration increases within a certain range, the number of radioactively grown nanoneedles gradually increases. When the mass of ZnO accounts for 16% of the composite powder, the micro / nanoparticles assemble into a 3D flower-like structure. The effect of sodium dodecylbenzenesulfonate (SDBS) on the surface morphology of the samples was investigated by comparing Comparative Examples 1, 4, and 5 with Example 1. Figure 2 i- Figure 2 l). When WO3 was prepared without the use of SDBS surfactant, bulk WO3 nanoparticle aggregates with a diameter of approximately 5 μm were obtained. Figure 2 i) Short nanoneedles are attached to the bulk aggregates. Compared with thin films and bulk materials, nanostructured materials have a larger interfacial area and a shorter carrier diffusion distance, thus promoting the separation and transfer of photogenerated carriers. When the sample contains Zn 2+ However, in the absence of SDBS, radioactively grown nanoneedles exist on the sample surface, but WO3 nanoparticles easily aggregate and are difficult to form flower-like morphologies. This indicates that Zn 2+ SDBS and other compounds can jointly regulate the growth and aggregation of nanocrystals. Compared with Comparative Examples 1 and 5, Examples 1, 3, and 10, after the samples underwent low surface energy treatment ( Figure 2 fh、 Figure 2 j and Figure 2 The roughness of the sample further increased, eventually forming a flower-like morphology with reentrant curvature. Figure 2 m).

[0083] To determine the chemical composition of each example and comparative example, XRD, FTIR, and XPS analyses were performed, and the results are as follows: Figure 3 As shown. From the XRD pattern, we can know ( Figure 3 a) In Example 10, a hexagonal WO3 system (JCPDS 75-2187) and a hexagonal ZnO system (JCPDS 36-1451) were generated. Peaks (102) and (110) correspond to hexagonal ZnO; peaks (100), (110), (001), (101), (200), (111), (201), (310), (221), and (401) correspond to the hexagonal WO3 system. Furthermore, by observing Comparative Examples 9 and 10, it was found that the addition of the surfactant SDBS and the fluorination process did not change the crystal structure of the composite material. From the FTIR spectra, it can be seen that ( Figure 3b) The peaks at 500-800 cm"1are the stretching vibrations of W-O-W bonds, the peak at 960 cm"1is characteristic of O-W-O, and the absorption band at 496 cm"1is the characteristic vibration of Zn-O bonds, indicating the successful generation of WO3and ZnO. The fluorinated sample produced three new peaks, of which the peaks at 1242 and 1207 cm"1are the stretching vibrations of -CF3, -CF2-, and the characteristic peak at 1149 cm"1is attributed to the siloxane produced by the hydrolysis and condensation of PFDTES and TEOS. XPS spectra determined the chemical composition of the materials of Comparative Example 3 (PWO3), Comparative Examples 8 and 9 (WZ-16%, WZ-20%), and Example 1 (FWZ-16%) Figure 2 c) The XRD full spectrum of PWO3powder only has W and O elements, the WZ powder adds Zn element, and the FWZ powder adds three new elements, F, Si, and C elements. In addition, the WZ and FWZ samples were analyzed by XPS fine spectrum to determine the valence state of the elements. Figure 2 d is the XPS spectrum of W 4f of PWO3and WZ. The W 4f region has two spin-orbit doublets (W4f(7 / 2) and W4f(5 / 2)), which verifies that the tungsten in the prepared composite micro-nanoparticles is W(6+) cation. For the WZ-16% sample, the 4f(7 / 2) and 4f(5 / 2) peaks are 35.08 eV and 37.23 eV, respectively, and for the WZ-20% sample, they are 34.99 eV and 37.12 eV, respectively. The slight shift in the absorption peaks is due to the addition of zinc acetate, which increases the strain in the lattice due to the generated Zn-W-O bond. Figure 2 e is the XPS spectrum of O 1s of PWO3and WZ. The binding energy of O 1s is decomposed into components of 529.94 eV and 531.55 eV, corresponding to Zn-W-O bonds and lattice oxygen (Ob) of tungsten, respectively. Figure 2 f- Figure 2 h is the XPS fine spectrum of C 1s, Zn 2p, and O 1s of FWZ-16%. The C 1s region shows the presence of -CF(3), -CF(2)-, CH(2)-CF(2), and C-C bonds, and no C-O bond indicates complete hydrolysis of PFDTES and TEOS. The Zn2p region has double peaks at 1021.7 and 1044.6 eV, attributed to Zn2p(1 / 2) and Zn2p(3 / 2), with a slit width of about 22.9 eV between the two. This indicates the presence of lattice zinc (Zn(2+)) in the WO3 / ZnO composite material. Fluorination adds a peak at 532.3 eV in the O 1s region, which is attributed to the Si-O-Si bond.

[0084] From Figure 4It can be seen that the tungsten oxide-based super-amphiphobic photochromic coating (FWZ-16%) prepared in Example 1 can be applied to more severe natural environments. Since the surface roughness of the super-amphiphobic coating is usually at the nanoscale, the mechanical strength is weak and easy to wear. Therefore, the low surface robustness is the main problem that limits the practical application of super-amphiphobic coatings. In order to solve this problem, the "adhesive + nanoparticles" treatment method is adopted, and the double-sided tape is used to assist the deposition of FWZ powder on the glass slide, which effectively eliminates the inherent weak durability of the super-amphiphobic surface, allowing it to be applied to more severe natural environments Figure 4 a) The relevant durability tests including sand impact, water impact, heat resistance, heat liquid resistance and corrosion solution resistance tests were carried out on it Figure 3 b-3f) The contact angle of FWZ-16% to water droplets from 0 to 95℃ and at 1 to 100℃ is greater than 150°; after 72h of UV irradiation, the contact angle (WCA) to water is 151.2±0.8°, and the contact angle (OCA) to oil is 146±1.6°; the contact angle to liquids of different PH values is greater than 150°. After placing the FWZ-16% surface under the faucet with a water flow rate of 1m / s for 10min, the WCA=152.5±3.9° and the OCA=142.15±2.4°. After 10g of sand was scoured and worn on the 45° inclined FWZ-16% from a height of 20cm, the contact angle was recorded every 5 times, and after 50 times of sand impact and wear, the WCA=151.3±0.7° and the OCA=141.5±1.6°. After experiencing all the mechanical and chemical durability tests, the surface still has super-hydrophobicity and high-oleophobicity. By realizing the super-amphiphobicity of the coating, the mechanical and chemical stability of the FWZ surface under severe environmental conditions is greatly improved, and the service life of the surface is prolonged.

[0085] Figure 5 As can be seen in a, the photochromic coatings with five different mass ratios of ZnO all have super-amphiphobicity, among which the sample with the best super-oleophobicity is Example 1 (FWZ-16%). From Figure 5 b, the contact angles of water, ethylene glycol, liquid paraffin, glycerol, and rapeseed oil on the coating surface provided by Example 1 can be observed, and the contact angle to water is 153.3±1.47° and the contact angle to rapeseed oil is 150.8±0.9°. With the change of the concentration of Zn 2+ The change of the concentration affects the micro-morphology of FWZ, and the increase of the surface roughness leads to the increase of the apparent contact angle. The micro-nano layered structure with reentrant curvature is beneficial to the Laplace pressure balance of the liquid droplets such as water and edible oil at the solid-liquid-gas interface to balance the gravity of the droplets, and finally generates an upward force, so that the droplets can stand on the modified surface in a spherical shape Figure 5 e-5f). Figure 5 c, Figure 5g-5k verified the extremely low adhesion of the FWZ-16% surface. Figure 5 c It can be seen that the adhesion of water and rapeseed oil on the FWZ-16% surface is 0.78 and 47.5 μN, respectively. Figure 5 d The silver mirror phenomenon of the FWZ-16% surface in the five test liquids indicates that there is an air layer between the rough texture structure and the liquid, which hinders the solid-liquid interface contact. Figure 5 g shows the rebound behavior of a 5 μl water droplet released from a height of 2 mm to the FWZ-16% surface. Figure 5 h-k are optical photographs of the four oil droplets moving down, contacting, extruding and separating from the surface of the coating, respectively, and the oil droplets do not leave any traces on the surface of the coating, which reflects the extremely low liquid-solid interface adhesion and excellent superamphiphobicity.

[0086] From Figure 6 It can be seen that the tungsten oxide-based superamphiphobic photochromic coating prepared in Example 1 is immersed in a high-adhesion methylene blue dyed aqueous solution, a mixture of carbon black and ethylene glycol, a rhodamine dyed glycerol, and rapeseed oil for 20 seconds, and after removing the wafer, the colored and uncolored surfaces remain clean. When water or oil rolls over or slides over the coating, the self-cleaning effect of the surface can remove hydrophilic or hydrophobic contaminants, keeping the surface clean.

[0087] From Figure 7 It can be seen that the tungsten oxide-based superamphiphobic photochromic coatings prepared in Comparative Example 6 (NWZ-16%), Comparative Example 8 (WZ-16%), Comparative Example 1 (NFWZ-16%) and Example 1 (FWZ-16%) all have different degrees of photochromism. As the UV irradiation time increases to 3 minutes, the color of the coating changes to blue to varying degrees, and after heating in air at 80°C for a certain time, it can be completely erased. From Figure 7 a-7d, it can be observed that the addition of sodium dodecyl benzene sulfonate and the introduction of fluorosilane can improve the efficiency of photochromism. By comparing Figure 7 a and 7b, the discoloration efficiency of the WZ-16% sample with added sodium dodecyl benzene sulfonate is greatly improved. When the WZ-16% surface is irradiated with ultraviolet light for 30 s, it is darker than the blue color of the NWZ-16% sample irradiated for 3 min ( Figure 7 a-7b). Similarly, after irradiating the FWZ-16% surface with ultraviolet light for 3 min, it is darker than the blue color of the NFWZ-16% sample ( Figure 7 c-7d). This is because the sample with added sodium dodecyl benzene sulfonate has a flower-like reentrant structure, which has a larger surface area than the block-like agglomerates.

[0088] From Figure 8As shown, by changing different copper sheet masks and traces erasing at 80°C (or natural fading at room temperature), UV irradiation can form different patterns on the same piece of photochromic coating Figure 8 a) As shown, the photochromic coating was irradiated by UV light for 3 min, and then the coating was placed in an oven at 80°C for 90 min to erase the pattern. Figure 8 b) As shown, by irradiating the FWZ-16% coating mask for 3 min, the part irradiated by UV light changed from white to blue. Then it was placed in an oven at 80°C for 90 min to erase the pattern, and the changed part returned to its original state. Subsequently, by the same steps, different patterns were formed on the same piece of photochromic coating in turn, and were erased. In addition, the photochromic coating was naturally placed in a room (temperature 10°C, humidity 62%), and the patterns on the photochromic coating gradually disappeared within 3 days. If the changed coating was placed in a dark room at room temperature, the changed patterns still existed after 20 days Figure 8 c).

[0089] The above description is only the preferred embodiment of the present application, and does not limit the present application in any form; any person skilled in the art can easily implement the present application according to the above description and the drawings; however, any equivalent changes, modifications and evolutions made by those skilled in the art within the scope of the technical solutions of the present application, using the above disclosed technical content, are equivalent embodiments of the present application; at the same time, any equivalent changes, modifications and evolutions made according to the essence of the present application to the above embodiments are still within the protection scope of the technical solutions of the present application.

Claims

1. A method for the preparation of a tungsten oxide-based superamphiphobic photochromic coating material, characterized by, The method comprises the following steps: 1) dissolving sodium tungstate dihydrate and sodium dodecyl benzene sulfonate in ionized water to obtain solution A, and then adding a strong acid to adjust the pH of the solution to 1-2 and stirring; dissolving oxalic acid and ammonium sulfate in deionized water to obtain solution B; mixing solution A and solution B and adding zinc acetate dihydrate, continuing to stir to obtain a precursor solution, and transferring the precursor solution into a reaction kettle, and after hydrothermal reaction, centrifuging and drying the product; 2) immersing the dried product in an HNO3 solution for acidification, and after centrifugation, drying and grinding, WO3 / ZnO powder is obtained; 3) dispersing the WO3 / ZnO powder in a mixture of ethanol, ammonia water and deionized water, and then adding tetraethyl orthosilicate and 1H, 1H, 2H, 2H-perfluorodecyl triethoxysilane, and stirring at room temperature to obtain an ultrabiphobic photochromic coating material.

2. The method of claim 1, wherein the tungsten oxide-based superamphiphobic photochromic coating material is prepared by the steps of: (a) preparing a tungsten oxide-based photochromic coating material; (b) preparing a superhydrophobic coating material; and (c) mixing the tungsten oxide-based photochromic coating material and the superhydrophobic coating material. In step 1), the mass ratio of sodium tungstate dihydrate, zinc acetate dihydrate and sodium dodecyl benzene sulfonate is 1:0.1-1:0.1-1.

3. The method for preparing a tungsten oxide-based superampholytic photochromic coating material according to claim 1, characterized in that, In step 1), the mass ratio of oxalic acid to ammonium sulfate is 1:0.5-10.

4. The method of claim 3, wherein the tungsten oxide-based superamphiphobic photochromic coating material is prepared by the steps of: In step 1), the hydrothermal reaction temperature is 100-200°C, and the reaction time is 1-10h.

5. The method of claim 3, wherein the tungsten oxide-based superamphiphobic photochromic coating material is prepared by the steps of: (a) preparing a tungsten oxide-based photochromic coating material; (b) preparing a superhydrophobic coating material; and (c) mixing the tungsten oxide-based photochromic coating material and the superhydrophobic coating material. In step 2), the concentration of the HNO3 solution is 0.01-10mol / L, and the soaking time is 5-20h.

6. The method of claim 1, wherein the tungsten oxide-based superamphiphobic photochromic coating material is characterized by: In step 3), the mass fraction of ZnO in the WO3 / ZnO powder is 10-20%.

7. The method of claim 6, wherein the tungsten oxide-based superamphiphobic photochromic coating material is prepared by the steps of: In step 3), the mass ratio of WO3 / ZnO powder, tetraethyl orthosilicate and 1H, 1H, 2H, 2H-perfluorodecyl triethoxysilane is 1:0.15-0.6:0.2-0.

9.

8. A tungsten oxide-based superamphiphobic photochromic coating, characterized in that, The coating is formed on the surface of a substrate by an auxiliary deposition method using the ultrabiphobic photochromic coating material prepared by the method of any one of claims 1-7.

9. The method of claim 8, wherein the tungsten oxide-based superamphiphobic photochromic coating is prepared by, The method comprises the following steps: The double-sided adhesive tape is adhered to the substrate, and then the ultrabiphobic photochromic coating material is uniformly coated on the surface of the double-sided adhesive tape, pressed, and then the excess material is shaken off to obtain a tungsten oxide-based ultrabiphobic photochromic coating.

10. The tungsten oxide-based ultrabiphobic photochromic coating according to claim 8 is applied in repeated writing under ultraviolet light.

Images