Preparation method of hollow silicon oxide nanotube coating with controllable size and application thereof in super-hydrophobic anti-reflection self-cleaning coating

Abstract

The present application belongs to the field of one-dimensional size nanometer material preparation and application, and particularly relates to a preparation method of a size-controllable hollow silica nanometer tube coating and application of the coating in a super-hydrophobic self-cleaning anti-reflection coating. The coating is prepared by high-temperature treatment of poly(methyl hydrogen siloxane) in an alkaline environment, and the specific preparation method is as follows: preparing a n-heptane or cyclohexane solution of poly(methyl hydrogen siloxane); placing the n-heptane or cyclohexane solution of poly(methyl hydrogen siloxane), ammonia water, ultrapure water and a substrate in a reaction kettle; adjusting the volume ratio of the ammonia water to the ultrapure water and the reaction temperature to prepare hollow nanometer tube coatings with different sizes. The average light transmittance of the coating prepared by the present application can reach 92.44% in the range of 400-800 nm, which is 2.4% higher than that of the substrate, the water contact angle is 156.1°, and the rolling angle is 0.75°. The silica nanometer tube coating has excellent self-cleaning properties.

Description

Technical Field

[0001] This invention belongs to the field of one-dimensional nanomaterial preparation and application, specifically relating to a method for preparing a size-controllable hollow silica nanotube coating and its application in a superhydrophobic, antireflective, and self-cleaning coating. Background Technology

[0002] Improving solar energy conversion efficiency is a crucial issue in photovoltaics. Increasing the light transmittance of photovoltaic panels is one of the key methods to achieve high conversion efficiency. Photovoltaic panels are prone to adhering to dust and other contaminants, leading to an increase in light refractive index and reducing photoelectric conversion efficiency. Therefore, the development of antireflective, self-cleaning coatings is of paramount importance.

[0003] Hydrophobicity and antireflection are competing properties. The sol-gel method is a common method for preparing antireflective films. Often, it is difficult to prepare a coating that combines superhydrophobicity and self-cleaning properties with antireflection using a simple sol-gel method. Instead, it is often superhydrophobic without antireflection or antireflection, or antireflection without superhydrophobicity and self-cleaning.

[0004] More than a decade ago, one-dimensional organosilicon nanowires (1D-SNFs), such as fibers and metal wires, were described. These one-dimensional organosilicon nanowires are often obtained by hydrolyzing trifunctional organosilicon monomers, such as trichloromethylsilane and 1H,1H,2H,2H-perfluorooctyltrichlorosilane, with water in a neutral or acidic humidity environment. They possess natural superhydrophobicity and can achieve anti-reflection and anti-reflection effects under specific conditions. Although the growth principle of one-dimensional nanowires is simple, the synthesis conditions are extremely demanding. For example, they require an expensive glove box to provide a vacuum environment, strict control of the humidity, or dynamic adjustment of the moisture content through a bubbling system while measuring it with a Karl Fischer moisture analyzer.

[0005] Existing methods for preparing superhydrophobic silicon nanotubes typically involve loading low surface energy materials (such as PDMS) onto templates such as carbon (C) or zinc oxide (ZnO), followed by removing the templates. To date, no template-free, naturally occurring superhydrophobic nanotubes have been found.

[0006] Therefore, it is of great significance to prepare superhydrophobic self-cleaning antireflective nanotube coatings in a simple and low-cost manner. Summary of the Invention

[0007] To address the problems identified in the background section, this invention provides a method for preparing a size-controllable hollow silica nanotube coating, and uses the resulting nanotube coating as a superhydrophobic, self-cleaning, and antireflective coating. The specific preparation method involves placing a solution of poly(methylhydrosiloxane) in n-heptane or cyclohexane, ammonia, water, and a substrate in a sealed reaction vessel and treating it at high temperature to obtain a superhydrophobic, self-cleaning, transparent coating.

[0008] The main steps of the preparation method are as follows:

[0009] (1) Prepare a solution of poly(methylhydrosiloxane) (PMHS) in n-heptane or cyclohexane with a volume fraction of 16.67%;

[0010] (2) Place the n-heptane or cyclohexane solution of poly(methylhydrosiloxane) (PMHS), ammonia, water, and the substrate in a reaction vessel;

[0011] The volume ratio of ammonia to water is 5-16:10-22, and the volume ratio of n-heptane or cyclohexane solution of poly(methylhydrosiloxane) (PMHS) to ammonia is 0.6-1.0:5-16.

[0012] The substrates are glass slides, sponges, wood, steel, iron sheets, fabrics, ceramics, and aluminum sheets.

[0013] (3) The reactor in step (2) is subjected to high temperature treatment at 130-220℃ for 2-4 hours to obtain a superhydrophobic antireflective hollow silicon oxide nanotube coating.

[0014] The advantages of this invention compared to the prior art are:

[0015] 1. The preparation process of this invention is simple, and the required equipment and reagents are inexpensive and readily available, which has obvious advantages in constructing superhydrophobic self-cleaning transparent coatings.

[0016] 2. The size of the nanotubes prepared by this invention can be controlled and adjusted according to the volume ratio of ammonia to water; the coverage of the nanotubes can be controlled by temperature, the volume ratio of ammonia to water, and reaction time.

[0017] 3. The coating prepared by this invention has high light transmittance, reaching 92.44%, which is 2.44% higher than that of bare glass. The water contact angle can reach 156.1° and the roll-off angle is 0.75°, achieving a superhydrophobic effect and possessing excellent self-cleaning ability.

[0018] 4. The coating prepared by this invention has excellent self-cleaning effect. It only requires a small amount of water to easily remove surface sand particles, leaving no stains on the coating surface. It can be used for self-cleaning of surfaces such as equipment, vehicles, and facilities. Attached image description:

[0019] Figure 1 Here is a scanning electron microscope image of the coating in Example 1;

[0020] Figure 2 Here is a scanning electron microscope image of the coating in Example 2;

[0021] Figure 3 Here is a scanning electron microscope image of the coating in Example 3;

[0022] Figure 4 Here is a scanning electron microscope image of the coating in Example 4;

[0023] Figure 5 Here is a scanning electron microscope image of the coating in Example 5;

[0024] Figure 6 This is a transmission electron microscope (TEM) image of the nanotubes obtained in Example 5;

[0025] Figure 7 Here is a scanning electron microscope image of the coating in Example 6;

[0026] Figure 8 Here is a scanning electron microscope image of the coating in Example 7;

[0027] Figure 9 Here is a scanning electron microscope image of the coating in Example 8;

[0028] Figure 10 Here is a scanning electron microscope image of the coating in Example 9;

[0029] Figure 11 Here is a scanning electron microscope image of the coating in Example 10;

[0030] Figure 12 Here is a scanning electron microscope image of the coating in Example 11;

[0031] Figure 13 The diagram shows the reaction apparatus for the examples and comparative examples. Detailed Implementation

[0032] The present invention will be further described below with reference to embodiments, but is not limited thereto.

[0033] Example 1

[0034] (1) Prepare a n-heptane solution of poly(methylhydrosiloxane) (PMHS) with a volume fraction of 16.67%;

[0035] (2) Place 0.8 mL of a 16.67% (v / v) poly(methylhydrosiloxane) (PMHS) n-heptane solution, 16 mL of ammonia water, 10 mL of water, and a glass slide into the reaction vessel;

[0036] This invention involves reacting ammonia, water, and a silicon source from a liquid state to a gaseous state at high temperature. Figure 13 The two small bottles contain a heptane solution of poly(methylhydrosiloxane) and ammonia, respectively. The purpose is to prevent poly(methylhydrosiloxane) from coming into direct contact with ammonia, thus preventing premature hydrolysis and condensation of poly(methylhydrosiloxane) with water under the catalysis of ammonia, which would generate byproducts.

[0037] (3) The reactor in step (2) was treated at 200℃ for 2 hours to obtain a superhydrophobic nanotube coating. The nanotubes had a diameter of about 66 nm and a length of more than 2 μm. The average transmittance of the coating in the range of 400-800 nm was 90.15%. The contact angle of 5 μL of water was measured to be 152.2° and the roll-off angle was less than 1°.

[0038] Example 2

[0039] (1) Prepare a n-heptane solution of poly(methylhydrosiloxane) (PMHS) with a volume fraction of 16.67%;

[0040] (2) Place 0.8 mL of a 16.67% (v / v) poly(methylhydrosiloxane) (PMHS) n-heptane solution, 16 mL of ammonia water, 16 mL of water, and a glass slide into the reaction vessel;

[0041] (3) The reactor in step (2) was treated at 200℃ for 2 hours to obtain a superhydrophobic nanotube coating. The nanotubes had a diameter of about 56nm and a length of 700nm to 1μm. The average transmittance of the coating at 400 to 800nm ​​was 90.31%. The contact angle of 5μL water was measured to be 151.4° and the roll-off angle was less than 1°.

[0042] Example 3

[0043] (1) Prepare a n-heptane solution of poly(methylhydrosiloxane) (PMHS) with a volume fraction of 16.67%;

[0044] (2) Place 0.8 mL of a 16.67% (v / v) poly(methylhydrosiloxane) (PMHS) n-heptane solution, 16 mL of ammonia water, 22 mL of water, and a glass slide into the reaction vessel;

[0045] (3) The reactor in step (2) was treated at 200℃ for 2 hours to obtain a superhydrophobic nanotube coating. The nanotubes had a diameter of about 80nm and a length of 400nm to 600nm. The average transmittance of the coating in the range of 400 to 800nm ​​was 89.34%, and the contact angle of 5μL water was measured to be 150.7°, with a roll-off angle of less than 1°.

[0046] Example 4

[0047] (1) Prepare a n-heptane solution of poly(methylhydrosiloxane) (PMHS) with a volume fraction of 16.67%;

[0048] (2) Place 0.8 mL of a 16.67% (v / v) poly(methylhydrosiloxane) (PMHS) n-heptane solution, 5 mL of ammonia water, 16 mL of water, and a glass slide into the reaction vessel;

[0049] (3) The reactor in step (2) was treated at 200℃ for 2 hours to obtain a superhydrophobic nanotube coating. The nanotubes had a diameter of about 46nm and a length of more than 2μm. The average transmittance of the coating in the range of 400-800nm ​​was 92.01%, the contact angle of 5μL water was measured to be 156.0°, and the roll-off angle was less than 1°.

[0050] Example 5

[0051] (1) Prepare a n-heptane solution of poly(methylhydrosiloxane) (PMHS) with a volume fraction of 16.67%;

[0052] (2) Place 0.8 mL of a 16.67% (v / v) poly(methylhydrosiloxane) (PMHS) n-heptane solution, 6.9 mL of ammonia water, 16 mL of water, and a glass slide into the reaction vessel;

[0053] (3) The reactor in step (2) was treated at 200℃ for 2 hours to obtain a superhydrophobic nanotube coating. The nanotubes had a diameter of about 49 nm and a length of 200-300 nm. The average transmittance of the coating at 400-800 nm was 92.44%. The contact angle of 5 μL water was measured to be 156.1° and the roll-off angle was less than 0.75°.

[0054] Example 6

[0055] (1) Prepare a n-heptane solution of poly(methylhydrosiloxane) (PMHS) with a volume fraction of 16.67%;

[0056] (2) Place 0.8 mL of a 16.67% (v / v) poly(methylhydrosiloxane) (PMHS) n-heptane solution, 10 mL of ammonia water, 16 mL of water, and a glass slide into the reaction vessel;

[0057] (3) The reactor in step (2) was treated at 200℃ for 2 hours to obtain a superhydrophobic nanotube coating. The nanotubes had a diameter of about 46 nm and a length of 600-700 nm. The average transmittance of the coating at 400-800 nm was 91.74%. The contact angle of 5 μL of water was measured to be 156.9° and the roll-off angle was less than 1°.

[0058] Example 7

[0059] (1) Prepare a n-heptane solution of poly(methylhydrosiloxane) (PMHS) with a volume fraction of 16.67%;

[0060] (2) Place 0.8 mL of a 16.67% (v / v) poly(methylhydrosiloxane) (PMHS) n-heptane solution, 6.9 mL of ammonia water, 16 mL of water, and a glass slide into the reaction vessel;

[0061] (3) The reactor in step (2) was treated at 130℃ for 2 hours. At this time, nanotubes began to grow, and a small amount of nanotubes were obtained. The diameter of the nanotubes was about 42nm and the length was less than 100nm. The average transmittance of the coating in the range of 400-800nm ​​was 90.05%. The contact angle of 5μL water was measured to be 107.6° and the roll-off angle was greater than 10°.

[0062] Example 8

[0063] (1) Prepare a n-heptane solution of poly(methylhydrosiloxane) (PMHS) with a volume fraction of 16.67%;

[0064] (2) Place 0.8 mL of a 16.67% (v / v) poly(methylhydrosiloxane) (PMHS) n-heptane solution, 6.9 mL of ammonia water, 16 mL of water, and a glass slide into the reaction vessel;

[0065] (3) The reactor in step (2) was treated at 160℃ for 2 hours, and a hydrophobic transparent nanotube coating was applied. The nanotubes had a diameter of about 48nm and a length of 110nm. The average transmittance of the coating in the range of 400-800nm ​​was 89.88%. The contact angle of 5μL water was measured to be 132.2° and the roll-off angle was greater than 10°.

[0066] Example 9

[0067] (1) Prepare a n-heptane solution of poly(methylhydrosiloxane) (PMHS) with a volume fraction of 16.67%;

[0068] (2) Place 0.8 mL of a 16.67% (v / v) poly(methylhydrosiloxane) (PMHS) n-heptane solution, 6.9 mL of ammonia water, 16 mL of water, and a glass slide into the reaction vessel;

[0069] (3) The reactor in step (2) was treated at 180℃ for 2 hours, and a superhydrophobic transparent nanotube coating was applied. The nanotubes had a diameter of about 48nm and a length of 200-300nm. The average transmittance of the coating in the range of 400-800nm ​​was 89.93%. The contact angle of 5μL water was measured to be 158.9° and the roll-off angle was less than 1°.

[0070] Example 10

[0071] (1) Prepare a n-heptane solution of poly(methylhydrosiloxane) (PMHS) with a volume fraction of 16.67%;

[0072] (2) Place 0.8 mL of a 16.67% (v / v) poly(methylhydrosiloxane) (PMHS) n-heptane solution, 6.9 mL of ammonia water, 16 mL of water, and a glass slide into the reaction vessel;

[0073] (3) The reactor in step (2) was treated at 220℃ for 2 hours, and a superhydrophobic transparent nanotube coating was applied. The nanotubes had a diameter of about 50 nm and a length of more than 1 μm. The average transmittance of the coating in the range of 400-800 nm was 85.71%, and the contact angle of 5 μL of water was measured to be 158.3°, with a roll-off angle of less than 1°.

[0074] Example 11

[0075] (1) Prepare a n-heptane solution of poly(methylhydrosiloxane) (PMHS) with a volume fraction of 16.67%;

[0076] (2) Place 0.8 mL of a 16.67% (v / v) poly(methylhydrosiloxane) (PMHS) n-heptane solution, 6.9 mL of ammonia water, 16 mL of water, and a glass slide into the reaction vessel;

[0077] (3) The reactor in step (2) was treated at 200℃ for 3 hours to obtain a superhydrophobic nanotube coating. The nanotubes had a diameter of about 86 nm and a length greater than 1 μm. The average transmittance of the coating in the range of 400 to 800 nm was 87.64%. The contact angle of 5 μL of water was measured to be 158.3° and the roll-off angle was less than 1°.

[0078] Example 12

[0079] (1) Prepare a n-heptane solution of poly(methylhydrosiloxane) (PMHS) with a volume fraction of 16.67%;

[0080] (2) Place 0.6 mL of a 16.67% (v / v) poly(methylhydrosiloxane) (PMHS) n-heptane solution, 6.9 mL of ammonia water, 16 mL of water, and a glass slide into the reaction vessel;

[0081] (3) The reactor in step (2) was treated at 200℃ for 2 hours to obtain a superhydrophobic nanotube coating. The nanotubes had a diameter of about 46 nm and a length of 200-300 nm. The average transmittance of the coating at 400-800 nm was 92.67%. The contact angle of 5 μL water was measured to be 154.1° and the roll-off angle was less than 0.75°.

[0082] Example 13

[0083] (1) Prepare a n-heptane solution of poly(methylhydrosiloxane) (PMHS) with a volume fraction of 16.67%;

[0084] (2) Place 1.0 mL of a 16.67% (v / v) poly(methylhydrosiloxane) (PMHS) n-heptane solution, 6.9 mL of ammonia water, 16 mL of water, and a glass slide into the reaction vessel;

[0085] (3) The reactor in step (2) was treated at 200℃ for 2 hours to obtain a superhydrophobic nanotube coating. The nanotubes had a diameter of about 52nm and a length of 300-400nm. The average transmittance of the coating at 400-800nm ​​was 90.39%. The contact angle of 5μL water was measured to be 157.4° and the roll-off angle was less than 0.75°.

[0086] Example 14

[0087] (1) Prepare a cyclohexane solution of poly(methylhydrosiloxane) (PMHS) with a volume fraction of 16.67%;

[0088] (2) Place 0.8 mL of cyclohexane solution of poly(methylhydrosiloxane) (PMHS) with a volume fraction of 16.67%, 6.9 mL of ammonia water, 16 mL of water, and a glass slide into the reaction vessel;

[0089] (3) The reactor in step (2) was treated at 200℃ for 2 hours to obtain a superhydrophobic nanotube coating. The nanotubes had a diameter of about 50 nm and a length of 200-300 nm. The average transmittance of the coating at 400-800 nm was 91.85%. The contact angle of 5 μL of water was measured to be 154.4° and the roll-off angle was less than 0.75°.

[0090] The embodiments described above are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for preparing a size-controllable hollow silica nanotube coating, characterized in that, The preparation method steps are as follows: (1) Prepare a solution of polymethylhydrosiloxane in n-heptane or cyclohexane; The volume fraction of the polymethylhydrosiloxane solution in n-heptane or cyclohexane is 16.67%. (2) Place the n-heptane or cyclohexane solution of polymethylhydrosiloxane, ammonia, water and substrate in a reaction vessel; so that the polymethylhydrosiloxane does not come into direct contact with the ammonia. The volume ratio of ammonia to water is 5-16:10-22, and the volume ratio of the n-heptane or cyclohexane solution of polymethylhydrosiloxane to ammonia is 0.6-1.0:5-16. The substrate can be glass slide, sponge, wood, steel, iron sheet, fabric, ceramic or aluminum sheet; (3) The reactor in step (2) is treated at high temperature to obtain a hollow silica nanotube coating with controllable size; The high-temperature treatment temperature is 130–220℃, and the treatment time is 2–4 hours.

2. A size-controllable hollow silica nanotube coating prepared by the method described in claim 1.

3. A size-controllable hollow silica nanotube coating prepared by the method described in claim 1 is used as a superhydrophobic antireflective self-cleaning coating.

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