Super-hydrophilic self-cleaning all-inorganic nano coating and coating preparation method

Abstract

The invention discloses a super-hydrophilic self-cleaning all-inorganic nano coating and a preparation method of a coating. The preparation method comprises the following steps: weighing 5-10% by weight of nano silicon dioxide; 1%-5% of sodium hydroxide; 0.5%-1.0% of nano sodium silicate; 1%-3% of nano titanium dioxide; 0.5%-1.0% of nano cerium dioxide; 90%-99% of deionized water; deionized water is used as a solvent, and sodium hydroxide is added into nano silicon dioxide to prepare silicon dioxide sol; adding nano sodium silicate, and fully stirring and mixing; then respectively adding nano cerium dioxide and nano titanium dioxide powder, and stirring at a high speed until the mixture is transparent, so as to obtain the super-hydrophilic self-cleaning all-inorganic nano coating. Enabling the coating to form a wet gel film on the surface of a coated sample; and naturally drying to obtain the super-hydrophilic self-cleaning all-inorganic nano coating. According to the invention, the bonding degree between the coating and the matrix is effectively improved, the service life is prolonged, and the cleaning and maintenance cost of the outdoor glass curtain wall is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of nano coatings, and in particular to a super-hydrophilic self-cleaning all-inorganic nano coating and a coating preparation method. Background Art

[0002] With the development of society, the progress of architectural technology and glass manufacturing level, and the increasing requirements of people for the beauty and comfort of buildings, the continuous innovation and progress of glass curtain wall technology have been promoted. Due to its beautiful appearance and good transparency, glass curtain walls have been widely used in modern buildings. After the promotion and application of glass curtain walls, it was found that there are still the following major problems: First, the temperature difference between the inside and outside causes the moisture in the air to condense and fog on its surface, reducing its visibility and affecting the use effect; second, pollutants such as dust and grease in the air are easy to adhere to its surface and affect the appearance and sight, which is also the biggest problem in the application of glass curtain walls. Although this problem can be cleaned manually, the difficulty and price of cleaning are very high. Therefore, the active exploration and development of glass coatings with self-cleaning functions by scientific and technological workers has become a hot topic in current research.

[0003] The prior art uses the sol-gel pulling method to prepare a SiO2-based super-hydrophilic self-cleaning coating with good anti-fouling effect, but the raw materials used in the preparation method are complex and contain a variety of organic components, which will cause secondary pollution to the environment when used. There is also a method of introducing tannic acid (TA) to modify CNTs after oxidation by the Fenton method to improve its dispersibility, and then mixing it evenly with dendritic nano-SiO2 sol and tetraethyl orthosilicate (TEOS) hydrolyzate, and then spraying the solution onto a white glass substrate through a low-cost spraying process, and finally curing it at room temperature to obtain a black transparent super-hydrophilic coating. However, anhydrous ethanol is used as a solvent in the preparation, and it needs to be carried out under acidic conditions during the preparation and construction process, which not only pollutes the environment, but also has a high cost and is not conducive to industrial production.

[0004] In view of this, it is necessary to develop a super hydrophilic self-cleaning all-inorganic nano coating and a coating preparation method. Summary of the invention

[0005] The technical problem solved by the present invention is to overcome the above-mentioned deficiencies in the prior art and provide a super hydrophilic self-cleaning all-inorganic coating with simple process, superior performance, low cost and natural drying at room temperature and air atmosphere.

[0006] A technical problem to be solved by the present invention is achieved through the following technical solutions:

[0007] A super-hydrophilic self-cleaning all-inorganic nano coating and a coating preparation method, comprising:

[0008] (1) Weigh the following raw materials by weight percentage:

[0009] Nano silicon dioxide 5% to 10%; sodium hydroxide 1% to 5%; nano sodium silicate 0.5% to 1.0%; nano titanium dioxide 1% to 3%; nano cerium dioxide 0.5% to 1.0%; deionized water 90% to 99%;

[0010] (2) Preparation of super-hydrophilic self-cleaning all-inorganic nano-coatings:

[0011] ① Using deionized water as solvent, weighing sodium hydroxide to prepare a solution with a weight concentration of 1% to 5%, then adding 5% to 10% of nano-silicon dioxide by weight, and fully stirring and dispersing to obtain a silica sol;

[0012] ② Add 0.5% to 1.0% by weight of nano sodium silicate to the prepared silica sol and stir and mix thoroughly;

[0013] ③ Add 0.5% to 1.0% of nano-cerium dioxide and 1% to 3% of nano-titanium dioxide powder by weight to the fully stirred sol, and stir at a high speed of 4000-8000 rpm until transparent to obtain a super-hydrophilic self-cleaning all-inorganic nano-coating;

[0014] (3) Preparation of super-hydrophilic self-cleaning all-inorganic nano-coating:

[0015] ① Using the sol-gel dipping method or spraying method, the super-hydrophilic self-cleaning all-inorganic nano-coating forms a wet gel film on the surface of the coating sample;

[0016] ② At room temperature, naturally dry in air atmosphere to obtain a super hydrophilic self-cleaning all-inorganic nano coating.

[0017] Preferably, the concentration of the sodium hydroxide solution is 4%, the weight percentage of the added nano-silicon dioxide is 8%, the weight percentage of the nano-sodium silicate is 0.7%, the weight percentage of the nano-cerium dioxide is 0.8%, and the weight percentage of the nano-titanium dioxide is 2%.

[0018] Preferably, the high speed stirring rate is 6500 rpm.

[0019] Preferably, the dipping time of the dipping method is 3-8 seconds.

[0020] The equipment used in the spraying method can be all equipment that produces atomization, and more preferably a household sprayer for watering flowers and a pressure sprayer.

[0021] In the above-mentioned super-hydrophilic self-cleaning all-inorganic nano-coating and coating preparation method, the nano-silicon dioxide is graded with one or several different specifications of nano-silicon dioxide with particle sizes of 2-5 nanometers, 10-15 nanometers and 25-35 nanometers prepared by gas phase method.

[0022] The super-hydrophilic self-cleaning all-inorganic nano-coating and coating preparation method as described above, wherein the particle size of the nano-sodium silicate is 10-25 nanometers and has good dispersibility.

[0023] The super-hydrophilic self-cleaning all-inorganic nano-coating and coating preparation method as described above, wherein the nano-titanium dioxide is an anatase phase crystal with photocatalytic function, has a particle size of 2-5 nanometers, and is water-soluble.

[0024] In the super-hydrophilic self-cleaning all-inorganic nano-coating and coating preparation method as described above, the particle size of the nano-cerium dioxide is 10-20 nanometers.

[0025] The super-hydrophilic self-cleaning all-inorganic nano-coating and coating preparation method as described above, wherein the coating sample is tempered glass or ordinary glass.

[0026] The above technical solution of the present invention has the following beneficial effects:

[0027] The preparation method of the self-cleaning coating of the present invention forms silica sol, which can effectively improve the bonding degree between the coating and the substrate, prolong the service life and reduce the cleaning and maintenance costs of the glass curtain wall due to outdoor use, which helps to promote the industrialization process of self-cleaning coatings for glass products. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention is a flow chart of a super-hydrophilic self-cleaning all-inorganic nano-coating and a coating preparation method.

[0029] Figure 2 The changes of the hydrophilic angle of Examples 1-4 over time.

[0030] Figure 3 The light transmittance test curves of Examples 1-4 and a blank glass plate without spraying are shown.

[0031] Figure 4 The self-cleaning effect diagram of Examples 1-4 after spraying carbon powder at the same time simulates rain. DETAILED DESCRIPTION

[0032] The specific embodiments of the present invention are described in detail below to facilitate a further understanding of the present invention.

[0033] All experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples are all commercially available unless otherwise specified.

[0034] Example 1

[0035] A super-hydrophilic self-cleaning all-inorganic nano coating and a coating preparation method, comprising:

[0036] (1) Weigh the following raw materials by weight:

[0037] 5g of nano silicon dioxide; 1g of sodium hydroxide; 0.5g of nano sodium silicate; 1g of nano titanium dioxide; 0.5g of nano cerium dioxide; 100ml of deionized water;

[0038] (2) Preparation of super-hydrophilic self-cleaning all-inorganic nano-coatings:

[0039] ① Measure 100 ml of deionized water and pour it into a beaker. Place the beaker on a magnetic stirrer and stir. Weigh 1 g of sodium hydroxide and slowly pour it into the beaker. Stir to fully dissolve it to prepare a sodium hydroxide solution. Weigh 5 g of nano-silicon dioxide and pour it into the sodium hydroxide solution. Continue stirring to obtain a silica sol.

[0040] ② Weigh 0.5 g of nano sodium silicate, add it to the obtained silica sol, and stir thoroughly to mix;

[0041] ③ Weigh 0.5g of nano-cerium dioxide and 1g of nano-titanium dioxide respectively, and add 0.5g of nano-cerium dioxide and 1g of nano-titanium dioxide to the fully stirred sol; remove the beaker from the magnetic stirrer, put it into a high-speed disperser, adjust the speed to 4000 rpm and disperse until transparent to obtain a super hydrophilic self-cleaning all-inorganic nano coating.

[0042] (3) Preparation of super-hydrophilic self-cleaning all-inorganic nano-coating:

[0043] ① Spray the obtained super-hydrophilic self-cleaning all-inorganic nano-coating onto the tempered glass plate and the ordinary glass plate, respectively, to form a wet gel film on the surface of the tempered glass and the ordinary glass plate;

[0044] ② Place in air atmosphere and room temperature for 24 hours to obtain a super hydrophilic self-cleaning all-inorganic nano coating.

[0045] Depend on Figure 2 It can be seen that the hydrophilic angle of the coating obtained in Example 1 remains below 10° over time. Figure 3 It can be seen that after spraying, the transparency of Example 1 increased by 1.74%. Figure 4It can be seen that when graphite powder is sprinkled at the same time, one side of the coating in Example 1 has an obvious self-cleaning effect.

[0046] Example 2

[0047] A super-hydrophilic self-cleaning all-inorganic nano coating and a coating preparation method, comprising:

[0048] (1) Weigh the following raw materials by weight:

[0049] 7g of nano silicon dioxide; 2.5g of sodium hydroxide; 0.6g of nano sodium silicate; 1.5g of nano titanium dioxide; 0.6g of nano cerium dioxide; 100ml of deionized water;

[0050] (2) Preparation of super-hydrophilic self-cleaning all-inorganic nano-coatings:

[0051] ① Measure 100 ml of deionized water and pour it into a beaker. Place the beaker on a magnetic stirrer and stir. Weigh 2.5 g of sodium hydroxide and slowly pour it into the beaker. Stir and fully dissolve it to prepare a sodium hydroxide solution. Weigh 7 g of nano-silicon dioxide and pour it into the sodium hydroxide solution. Continue stirring to obtain a silica sol.

[0052] ② Weigh 0.6 g of nano sodium silicate, add it to the obtained silica sol, and stir thoroughly to mix;

[0053] ③ Weigh 0.6g of nano-cerium dioxide and 1.5g of nano-titanium dioxide respectively, and add 0.6g of nano-cerium dioxide and 1.5g of nano-titanium dioxide to the fully stirred sol; remove the beaker from the magnetic stirrer, put it into a high-speed disperser, adjust the speed to 5000 rpm and disperse until transparent to obtain a super hydrophilic self-cleaning all-inorganic nano coating.

[0054] (3) Preparation of super-hydrophilic self-cleaning all-inorganic nano-coating:

[0055] ① Spray the obtained super-hydrophilic self-cleaning all-inorganic nano coating onto the tempered glass and the ordinary glass plate, respectively, to form a wet gel film on the surface of the tempered glass and the ordinary glass plate;

[0056] ② Place in air atmosphere and room temperature for 24 hours to obtain a super hydrophilic self-cleaning all-inorganic nano coating.

[0057] Depend on Figure 2 It can be seen that the hydrophilic angle of the coating obtained in Example 2 remains at about 8° over time. Figure 3 It can be seen that after spraying, the transparency of Example 2 increased by 2.24%. Figure 4 It can be seen that when graphite powder is sprinkled at the same time, the coating side has an obvious self-cleaning effect.

[0058] Example 3

[0059] A super-hydrophilic self-cleaning all-inorganic nano coating and a coating preparation method, comprising:

[0060] (1) Weigh the following raw materials by weight:

[0061] 8g of nano silicon dioxide; 4g of sodium hydroxide; 0.7g of nano sodium silicate; 2g of nano titanium dioxide; 0.8g of nano cerium dioxide; 100ml of deionized water;

[0062] (2) Preparation of super-hydrophilic self-cleaning all-inorganic nano-coatings:

[0063] ① Measure 100 ml of deionized water and pour it into a beaker. Place the beaker on a magnetic stirrer and stir. Weigh 4 g of sodium hydroxide and slowly pour it into the beaker. Stir and fully dissolve it to prepare a sodium hydroxide solution. Weigh 8 g of nano-silicon dioxide and pour it into the sodium hydroxide solution. Continue stirring to obtain a silica sol.

[0064] ② Weigh 0.7 g of nano sodium silicate, add it to the obtained silica sol, and stir thoroughly;

[0065] ③ Weigh 0.8g of nano-cerium dioxide and 2g of nano-titanium dioxide respectively, and add 0.8g of nano-cerium dioxide and 2g of nano-titanium dioxide to the fully stirred sol; remove the beaker from the magnetic stirrer, put it into a high-speed disperser, adjust the speed to 6500 rpm and disperse until transparent to obtain a super hydrophilic self-cleaning all-inorganic nano coating.

[0066] (3) Preparation of super-hydrophilic self-cleaning all-inorganic nano-coating:

[0067] ① Spray the obtained super-hydrophilic self-cleaning all-inorganic nano coating onto the tempered glass and the ordinary glass plate, respectively, to form a wet gel film on the surface of the tempered glass and the ordinary glass plate;

[0068] ② Place in air atmosphere and room temperature for 24 hours to obtain a super hydrophilic self-cleaning all-inorganic nano coating.

[0069] Depend on Figure 2 It can be seen that the hydrophilic angle of the coating obtained in Example 3 reaches super hydrophilicity. When the dripping time exceeds 2 seconds, the hydrophilic angle is maintained at about 3°. Figure 3 It can be seen that after spraying, the transparency of Example 3 increased by 2.93%. Figure 4 It can be seen that when graphite powder is sprinkled at the same time, the coating side has a more obvious self-cleaning effect.

[0070] Example 4

[0071] A super-hydrophilic self-cleaning all-inorganic nano coating and a coating preparation method, comprising:

[0072] (1) Weigh the following raw materials by weight:

[0073] Nano silicon dioxide 10g; sodium hydroxide 5g; nano sodium silicate 1g; nano titanium dioxide 3g; nano cerium dioxide 1g; deionized water 100ml;

[0074] (2) Preparation of super-hydrophilic self-cleaning all-inorganic nano-coatings:

[0075] ① Measure 100 ml of deionized water and pour it into a beaker. Place the beaker on a magnetic stirrer and stir. Weigh 5 g of sodium hydroxide and slowly pour it into the beaker. Stir to fully dissolve it to prepare a sodium hydroxide solution. Weigh 10 g of nano-silicon dioxide and pour it into the sodium hydroxide solution. Continue stirring to obtain a silica sol.

[0076] ② Weigh 1g of nano sodium silicate, add it to the obtained silica sol, and stir thoroughly to mix;

[0077] ③ Weigh 1g of nano-cerium dioxide and 3g of nano-titanium dioxide respectively, and add 1g of nano-cerium dioxide and 3g of nano-titanium dioxide to the fully stirred sol; remove the beaker from the magnetic stirrer, put it into a high-speed disperser, adjust the speed to 8000 rpm and disperse until transparent to obtain a super hydrophilic self-cleaning all-inorganic nano coating.

[0078] (3) Preparation of super-hydrophilic self-cleaning all-inorganic nano-coating:

[0079] ① Spray the obtained super-hydrophilic self-cleaning all-inorganic nano coating onto the tempered glass and the ordinary glass plate, respectively, to form a wet gel film on the surface of the tempered glass and the ordinary glass plate;

[0080] ② Place in air atmosphere and room temperature for 24 hours to obtain a super hydrophilic self-cleaning all-inorganic nano coating.

[0081] Depend on Figure 2 It can be seen that the hydrophilic angle of the coating obtained in Example 4 remains at about 7.2° over time. Figure 3 It can be seen that after spraying, the transparency of Example 4 increased by 2.29%. Figure 4 It can be seen that when graphite powder is sprinkled at the same time, the coating side has an obvious self-cleaning effect.

[0082] Although the present invention has been disclosed as above by the embodiments, it is not intended to limit the present invention. Any person skilled in the art may make various choices and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention is limited by the claims and their equivalents.

Claims

1. A super-hydrophilic self-cleaning all-inorganic nano coating and coating preparation method, characterized in that: include: (1) Weigh the following raw materials by weight percentage: Nano silicon dioxide 5% to 10%; sodium hydroxide 1% to 5%; nano sodium silicate 0.5% to 1.0%; nano titanium dioxide 1% to 3%; nano cerium dioxide 0.5% to 1.0%; deionized water 90% to 99%; (2) Preparation of super-hydrophilic self-cleaning all-inorganic nano-coatings: ① Using deionized water as solvent, weighing sodium hydroxide to prepare a solution with a weight concentration of 1% to 5%, then adding 5% to 10% of nano-silicon dioxide by weight, and fully stirring and dispersing to obtain a silica sol; ② Add 0.5% to 1.0% by weight of nano sodium silicate to the prepared silica sol and stir and mix thoroughly; ③ Add 0.5% to 1.0% of nano-cerium dioxide and 1% to 3% of nano-titanium dioxide powder by weight to the fully stirred sol, and stir at a high speed of 4000-8000 rpm until transparent to obtain a super-hydrophilic self-cleaning all-inorganic nano-coating; (3) Preparation of super-hydrophilic self-cleaning all-inorganic nano-coating: ① Using the sol-gel dipping method or spraying method, the super-hydrophilic self-cleaning all-inorganic nano-coating forms a wet gel film on the surface of the coating sample; ② At room temperature, naturally dry in air atmosphere to obtain a super-hydrophilic and self-cleaning all-inorganic nano-coating.

2. A super-hydrophilic self-cleaning all-inorganic nano coating and coating preparation method as claimed in claim 1, characterized in that: The concentration of the sodium hydroxide solution is selected to be 4%, the weight percentage of the added nano silicon dioxide is 8%, the weight percentage of the nano sodium silicate is 0.7%, the weight percentage of the nano cerium dioxide is 0.8%, and the weight percentage of the nano titanium dioxide is 2%.

3. A super-hydrophilic self-cleaning all-inorganic nano coating and coating preparation method as claimed in claim 1, characterized in that: The nano silicon dioxide is prepared by a gas phase method and is graded into one or more nano silicon dioxides of different specifications, among which the particle sizes are 2-5 nanometers, 10-15 nanometers and 25-35 nanometers.

4. A super-hydrophilic self-cleaning all-inorganic nano coating and coating preparation method as claimed in claim 1, characterized in that: The particle size of nano sodium silicate is 10-25 nanometers and has good dispersibility.

5. A super-hydrophilic self-cleaning all-inorganic nano coating and coating preparation method as claimed in claim 1, characterized in that: Nano titanium dioxide is an anastasia phase crystal with photocatalytic function, a particle size of 2-5 nanometers, and is water-soluble.

6. A super-hydrophilic self-cleaning all-inorganic nano coating and coating preparation method as claimed in claim 1, characterized in that: The particle size of nano-cerium dioxide is 10-20 nanometers.

7. A super-hydrophilic self-cleaning all-inorganic nano coating and coating preparation method as claimed in claim 1, characterized in that: The coating sample is tempered glass or ordinary glass.

8. A super-hydrophilic self-cleaning all-inorganic nano coating and coating preparation method as claimed in claim 1, characterized in that: The equipment used in the spraying method is a device capable of generating atomization.

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