A method for producing a laminated film having hydrophilicity

Abstract

The application discloses a preparation method of a laminated film with hydrophilicity, and belongs to the technical field of film coating. The film prepared by using a liquid phase method is divided into a titanium dioxide layer film and an aluminum phosphate layer film, and the uniformity of the film is better than that of a single layer film. The titanium dioxide layer film has high photocatalytic activity under ultraviolet irradiation, can degrade organic pollutants, and has strong hydrophilicity, and a hydrophilic angle is quickly increased and spread to play a transparent and self-cleaning role. The aluminum phosphate has special P-O and Al-O two kinds of tetrahedral structures which are strictly ordered and alternately arranged to form a unique molecular structure, and the hydrophilic film with a pore structure is easily formed, can play a synergistic role with the titanium dioxide layer film, and can enhance the hydrophilicity of the laminated film. The film is coated by using a pulling method, the operation is simple, and the uniformity of the film can be effectively improved. Therefore, the film prepared by the application has excellent hydrophilic performance, good self-cleaning effect and good uniformity, and has important application value in the technical field of film coating.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, specifically, it relates to a method for preparing a hydrophilic multilayer thin film. Background Technology

[0002] With advancements in technology and rising demands for quality of life, hydrophilic films, as a functional material, are gaining increasing market favor. They not only improve the surface properties of materials, enhancing product comfort and lifespan, but also provide unique protection in specific environments. For example, in solar photovoltaic cover glass, hydrophilic films possess self-cleaning capabilities, significantly reducing the cleaning and maintenance costs of photovoltaic modules.

[0003] Currently, water-based aluminum phosphate films are commonly used for hydrophilic films. However, when directly depositing water-based aluminum phosphate film coating solutions onto glass, the film uniformity may decrease, resulting in incomplete film coverage and reduced film performance. Therefore, it is urgent to solve this problem to meet the higher demands of the coating technology field. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing aluminum titanate nanofibers.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A method for preparing a hydrophilic multilayer thin film includes the following steps:

[0007] S1. Cut a piece of glass as the coating substrate, wipe it with a lint-free cloth, then immerse the cut glass in acetone, sodium ethoxide ethanol solution and hydrochloric acid aqueous solution in sequence, and finally put it in water and clean it with ultrasonic waves to remove the residual cleaning liquid and impurities on the glass to obtain the glass substrate.

[0008] S2. Mix ethanol and acetylacetone, stir and heat for 30 min, add tetrabutyl titanate, stir for another 30 min, add an appropriate amount of deionized water, adjust the pH of the system with hydrochloric acid solution, add N,N-dimethylformamide, continue stirring for 3 h, and age for 48 h to obtain titanium dioxide sol.

[0009] S3. Mix phosphoric acid and water and stir for 30 minutes. Add aluminum dihydrogen phosphate and stir evenly. Then add polyethylene glycol and finally add sodium dodecyl sulfonate and citric acid. Continue stirring for 2 hours and let stand for 24 hours to obtain aluminum phosphate coating solution.

[0010] Using aluminum-containing chemicals such as aluminum phosphate as raw materials, and adding long-chain humectants such as polyethylene glycol and sodium dodecyl sulfonate ionic surfactants as water as solvent, the resulting aluminum phosphate coating solution has better uniformity and more even film thickness.

[0011] S4. Immerse the glass substrate obtained in step S1 into the titanium dioxide sol obtained in step S2, then lift the substrate material and dry it at 120°C. After drying, heat treat it at 450°C. After the bottom film cools down, immerse the substrate material in the aluminum phosphate coating solution again. Then, slowly lift the substrate material again and let it stand at 30°C for 30 minutes. After curing, heat treat it at 350°C and cool it to obtain a hydrophilic laminated film.

[0012] Furthermore, in step S2, the molar ratio of ethanol to tetrabutyl titanate is 60:1.

[0013] Furthermore, in step S2, the molar ratio of tetrabutyl titanate to acetylacetone is 1:1.

[0014] Furthermore, in step S2, the molar ratio of deionized water to tetrabutyl titanate is 4:1.

[0015] Furthermore, in step S2, the mass fraction of the hydrochloric acid solution is 6-12%, and the pH of the system is adjusted to 1-2.

[0016] Furthermore, in step S3, the ratio of phosphoric acid, water, aluminum dihydrogen phosphate, polyethylene glycol, sodium dodecyl sulfonate, and citric acid is 10g:100mL:12g:5g:2g:2g.

[0017] Furthermore, in step S3, the molecular weight of polyethylene glycol is 800-1000.

[0018] Furthermore, the lifting speed in step S4 is 1000-2000 μm / s.

[0019] The prepared hydrophilic laminated film consists of a titanium dioxide layer and an aluminum phosphate layer. The titanium dioxide layer exhibits high photocatalytic activity under ultraviolet irradiation, enabling it to degrade organic pollutants. It is also highly hydrophilic, with its hydrophilic angle rapidly increasing and spreading out to achieve transparency and self-cleaning properties. The aluminum phosphate layer contains two special tetrahedral structures, PO and Al-O, arranged in a strictly ordered and alternating manner to form a unique molecular structure. This structure easily forms a hydrophilic film with a porous structure, which can synergistically enhance the hydrophilicity of the laminated film with the titanium dioxide layer. Furthermore, this bilayer film structure exhibits better uniformity compared to a single-layer film.

[0020] The beneficial effects of this invention are:

[0021] 1. The film obtained by this invention consists of a titanium dioxide layer and an aluminum phosphate layer. The titanium dioxide layer has strong hydrophilicity and good self-cleaning properties. The aluminum phosphate layer can work synergistically with the titanium dioxide layer to enhance the hydrophilicity of the laminated film and has good uniformity.

[0022] 2. By adjusting the pH value with acid to control the hydrolysis rate and using the dip-coating method, the operation is not only simple, but also effectively improves the uniformity of the film.

[0023] Therefore, the thin film prepared by this invention has excellent hydrophilicity, good self-cleaning effect and uniformity, and has important application value in the field of coating technology. Attached Figure Description

[0024] The invention will now be further described with reference to the accompanying drawings.

[0025] Figure 1 This is a diagram of the thin film structure of the present invention.

[0026] Figure 2 This is a flow chart of the coating process of the present invention.

[0027] Figure 3 This is a static water contact angle test diagram from Embodiment 1 of the present invention. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1

[0030] according to Figure 2 The steps shown in the flowchart are for preparing hydrophilic multilayer films:

[0031] S1. Cut a 40×75mm glass as the coating substrate, wipe it with a lint-free cloth, then immerse the glass substrate in acetone, sodium ethoxide ethanol solution and hydrochloric acid aqueous solution in sequence, and finally put it in water and use ultrasonic cleaning to remove the residual cleaning liquid and impurities on the glass to obtain the glass substrate.

[0032] S2. Mix 276g of ethanol and 28g of acetylacetone, stir and heat for 30min, add 34g of tetrabutyl titanate, stir for another 30min, add an appropriate amount of 40g of deionized water, adjust the pH of the system to 1 with hydrochloric acid solution (mass fraction of 6%), then add N,N-dimethylformamide, continue stirring for 3h, and age for 48h to obtain titanium dioxide sol.

[0033] S3. Mix 10g of phosphoric acid with 100mL of water and stir for 30min. Add 12g of aluminum dihydrogen phosphate and stir evenly. Then add 5g of polyethylene glycol (molecular weight 800), and finally add 2g of sodium dodecyl sulfonate and 2g of citric acid. Continue stirring for 2h and let stand for 24h to obtain aluminum phosphate coating solution.

[0034] S4. Immerse the glass substrate obtained in step S1 into the titanium dioxide sol obtained in step S2, then pull up the substrate material (pulling speed is 1000μm / s) and dry it at 120℃. After drying, heat treat it at 450℃. After the bottom film cools down, immerse the substrate material in the aluminum phosphate coating solution again, then slowly lift the substrate material again and let it stand at 30℃ for 30 minutes. After curing, heat treat it at 350℃ and cool it to obtain a hydrophilic laminated film.

[0035] Example 2

[0036] according to Figure 2 The steps shown in the flowchart are for preparing hydrophilic multilayer films:

[0037] S1. Cut a 40×75mm glass as the coating substrate, wipe it with a lint-free cloth, then immerse the glass substrate in acetone, sodium ethoxide ethanol solution and hydrochloric acid aqueous solution in sequence, and finally put it in water and use ultrasonic cleaning to remove the residual cleaning liquid and impurities on the glass to obtain the glass substrate.

[0038] S2. Mix 552g of ethanol and 28g of acetylacetone, stir and heat for 30min, add 68g of tetrabutyl titanate, stir for another 30min, add an appropriate amount of 80g of deionized water, adjust the pH of the system to 2 with hydrochloric acid solution (mass fraction of 12%), then add N,N-dimethylformamide, continue stirring for 3h, and age for 48h to obtain titanium dioxide sol.

[0039] S3. Mix 2g of phosphoric acid with 200mL of water and stir for 30min. Add 24g of aluminum dihydrogen phosphate and stir evenly. Then add 10g of polyethylene glycol (molecular weight 1000). Finally, add 4g of sodium dodecyl sulfonate and 4g of citric acid. Continue stirring for 2h and let stand for 24h to obtain aluminum phosphate coating solution.

[0040] S4. Immerse the glass substrate obtained in step S1 into the titanium dioxide sol obtained in step S2, then pull up the substrate material (pulling speed is 2000 μm / s) and dry it at 120°C. After drying, heat treat it at 450°C. After the bottom film cools down, immerse the substrate material in the aluminum phosphate coating solution again, then slowly lift the substrate material again and let it stand at 30°C for 30 min. After curing, heat treat it at 350°C and cool it to obtain a hydrophilic laminated film.

[0041] The contact angle of the hydrophilic laminated film prepared in Example 1 was measured, and the results are as follows: Figure 3As shown, the contact angle is 85.75°, which is less than 90°. Therefore, the film prepared by this invention has excellent hydrophilicity, good self-cleaning effect and uniformity, and has important application value in the field of coating technology.

[0042] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0043] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a hydrophilic multilayer thin film, characterized in that, The method comprises the following steps: S1, cutting glass as a coating substrate, then cutting the glass is immersed in acetone, sodium ethoxide ethanol solution and hydrochloric acid solution, and finally put into water, cleaning, to get glass substrate; S2, ethanol and acetylacetone mixed stirring heating 30 min, adding tetrabutyl titanate, stirring 30 min after adding the appropriate amount of deionized water, with hydrochloric acid solution to adjust the system pH, then adding N, N-dimethylformamide, continue to stir 3h, aging 48h, to get titanium dioxide sol; S3, phosphoric acid and water mixed stirring 30 min, adding aluminum dihydrogen phosphate, stirring uniform after adding polyethylene glycol, finally adding sodium dodecyl sulfonate and citric acid, continue to stir 2h, static 24h to get aluminum phosphate coating solution; S4, the glass substrate obtained in step S1 is immersed in the titanium dioxide sol obtained in step S2, then the substrate material is pulled up and dried at 120℃, after drying, heat treatment is carried out at 450℃, after the bottom layer film is cooled, the substrate material is immersed in the aluminum phosphate coating solution again, then the substrate material is pulled up slowly again and is placed in 30℃ for 30 min, after solidification, heat treatment is carried out at 350℃, and cooling is carried out, to get a laminated film with hydrophilicity. In step S2, the mass fraction of hydrochloric acid solution is 6-12%, and the pH of the system is adjusted to 1-2.

2. The method for preparing a hydrophilic multilayer thin film according to claim 1, characterized in that, In step S2, the molar ratio of ethanol to tetrabutyl titanate is 60:

1.

3. The method for preparing a hydrophilic multilayer thin film according to claim 1, characterized in that, In step S2, the molar ratio of tetrabutyl titanate to acetylacetone is 1:

1.

4. The method for preparing a hydrophilic multilayer film according to claim 1, characterized in that, In step S2, the molar ratio of deionized water to tetrabutyl titanate is 4:

1.

5. The method of claim 1, wherein the method further comprises the step of: In step S3, the amount ratio of phosphoric acid, water, aluminum dihydrogen phosphate, polyethylene glycol, sodium dodecyl sulfonate and citric acid is 10g:100mL:12g:5g:2g:2g. ​ 6. The method for preparing a hydrophilic multilayer thin film according to claim 1, characterized in that, In step S3, the molecular weight of polyethylene glycol is 800-1000.

7. The method of claim 1, wherein the method further comprises the step of: In step S4, the pulling speed is 1000-2000μm / s. ​

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