CN115404004B

CN115404004B - Preparation and application of transparent super-hydrophobic coating

Info

Publication number: CN115404004B
Application number: CN202211150617.2A
Authority: CN
Inventors: 陶芙蓉; 任方圆; 刘海龙; 刘利彬; 尚盈; 杨焕焕; 崔月芝
Original assignee: Qilu University of Technology
Current assignee: Qilu University of Technology
Priority date: 2022-09-21
Filing date: 2022-09-21
Publication date: 2023-08-01
Anticipated expiration: 2042-09-21
Also published as: CN115404004A

Abstract

The invention belongs to the field of preparation of super-hydrophobic coatings, and provides a transparent coatingPreparation and application of transparent superhydrophobic coating. First, a transparent low surface energy adhesive (F-HP-Si) was synthesized using 3-aminopropyl trimethoxysilane (KH-540) and 1H, 2H-perfluoro decyl trimethoxysilane (FAS). Small amounts of F-HP-Si with fumed silica (SiO ₂ 15 nm) to prepare transparent super-hydrophobic coating, and preparing transparent super-hydrophobic coating on glass, cotton cloth and other substrates by spray coating or dip coating method. The coating has excellent superhydrophobicity (WCA)>160 DEG) and good transmittance>70%,400nm-800 nm). And, the coating material has excellent chemical stability, and has superhydrophobic performance after being soaked in acid (ph=1), alkali (ph=13), salt (saturation concentration) and various organic solvents for 30 hours.

Description

Preparation and application of transparent super-hydrophobic coating

Technical Field

The invention belongs to the field of preparation of super-hydrophobic coatings, and particularly relates to preparation of a transparent super-hydrophobic coating.

Background

The disclosure of this background section is only intended to increase the understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art already known to those of ordinary skill in the art.

The transparency of superhydrophobic materials is critical to whether they can be used in transparent materials such as glass. The high transmittance and super-hydrophobic property of the coating on a smooth substrate such as glass are important points and difficulties of the subject while the coating has low surface energy and high roughness.

The society of today is very fast developing and people are increasingly dependent on energy. The development of new energy is more and more indispensable, and the application of the photoelectric conversion technology of the solar cell is expanded along with the comprehensive development of new energy, which is a great step of the historical development of human beings. However, cleaning of large-area photovoltaic panels is a major problem, and conventional cleaning methods may consume a lot of manpower and material resources and may cause damage to the photovoltaic panels. The application of the transparent super-hydrophobic coating can solve the self-cleaning problem of the solar photovoltaic panel to a great extent. In the course of modern experiments, various optical and glass instruments are often used, and many advanced chemical precision instruments are very expensive. However, as long as transparent materials such as glass lenses, glass lenses and the like are concerned, they are all plagued by a problem that they are contaminated with dust, water and the like to cause a decrease in transparency thereof, thereby requiring a cost of manpower and material resources for cleaning. In daily life, most manual cleaning is relatively easy after the surface of the glass material is polluted, but the manual cleaning cost of glass lenses and the like of many precise glass instruments is relatively high and even equipment damage can be caused by improper operation. Therefore, it is important to have a self-cleaning function for some high-precision and expensive glassware. The glassware with self-cleaning function can greatly reduce labor cost and time cost required for maintenance. Greatly improves the working efficiency and has profound effects on the development of science and the progress of science and technology. It is therefore necessary to develop a coating of a material with light-transmitting and self-cleaning properties.

Disclosure of Invention

In order to solve the problems, the invention provides a preparation method of a transparent super-hydrophobic coating, which has excellent super-hydrophobicity (WCA >160 DEG) and good transmittance (> 70%,400nm-800 nm). In addition, the coating material has excellent chemical stability, has super-hydrophobic performance after being soaked in acid (PH=1), alkali (PH=13), salt (saturation concentration) and various organic solvents for 30 hours, and has great application prospect.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

in a first aspect of the present invention, there is provided a method for preparing a transparent superhydrophobic coating, comprising:

uniformly mixing KH-540 and 1H, 2H-perfluoro decyl trimethoxy silane in a solvent, and heating to react to obtain F-HP-Si;

uniformly dispersing the F-HP-Si in a solvent, adding fumed silica, sufficiently oscillating, heating and mechanically stirring to obtain a dispersion liquid;

loading the dispersion liquid on a substrate material, and drying to obtain the final product.

In a second aspect of the invention, a transparent superhydrophobic coating prepared by the method described above is provided.

In a third aspect, the invention provides an application of the transparent super-hydrophobic coating in the fields of dust prevention, self cleaning or corrosion prevention.

The beneficial effects of the invention are that

(1) The invention synthesizes fluorine-rich transparent adhesive by using 3-aminopropyl trimethoxy silane (KH-540) and 1H, 2H-perfluoro decyl trimethoxy silane (FAS) as raw materials, and adds 15nm fumed silica to prepare transparent super-hydrophobic coating, and researches the super-hydrophobicity and the transmittance thereof. The optimal dosage of F-HP-Si and SiO2 nano particles and the number of spraying layers are respectively 0.3g, 0.1g and 20 layers. The coating has excellent superhydrophobicity and good transparency, and the transmittance can reach more than 72% in the visible light wavelength.

(2) The super-hydrophobic coating of the invention does not depend on a substrate, can be applied to the surfaces of objects such as glass, wood boards, steel plates, ceramics, cotton cloth and the like, and shows excellent hydrophobic performance (> 160 °). The transparent coating has excellent chemical stability, and has superhydrophobic performance after being soaked in acid (PH=1), alkali (PH=13), salt (saturation concentration) and various organic solvents for 30 hours. And the coated glass plate has good self-cleaning capability and high industrial production potential.

(3) The preparation method is simple, has strong practicability and is easy to popularize.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention.

FIG. 1 is a plot of the change in WCA and transmittance with 15nm fumed silica for the quantification of F-HP-Si (0.3 g);

FIG. 2 is a plot of WCA and transmittance versus F-HP-Si for a 15nm fumed silica basis (0.1 g);

FIG. 3 is a graph showing the effect of the number of different spray layers on hydrophobicity and transmittance;

FIG. 4 is an SEM image of a coated glass surface;

FIG. 5 shows the distribution of different elements on the surface of a sample glass;

FIG. 6 is a graph of water contact angle (a) and roll angle (b) of a coated glass sheet;

FIG. 7 is a graph of contact angle of a modified glass sheet immersed in different solutions as a function of time;

FIG. 8 is a graph showing the transmittance of modified glass versus unmodified glass;

FIG. 9 is a laboratory simulation of the self-cleaning effect of a superhydrophobic coating;

FIG. 10 is a schematic representation of the superhydrophobicity of (a) an unmodified wood board, and (b) and a modified wood board. (c) And (3) a super-hydrophobic schematic diagram of an unmodified steel plate (left) and a modified steel plate (right). (d) superhydrophobic schematic of modified ceramic. (e) Super-hydrophobic schematic diagrams of unmodified cotton cloth (left) and modified cotton cloth (right).

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

A preparation method of a transparent super-hydrophobic coating comprises the following steps:

In some embodiments, the mass ratio of KH-540 to 1H, 2H-perfluorodecyl trimethoxysilane is from 2 to 4:1 or 3:1.

in some embodiments, the mass ratio of F-HP-Si to fumed silica is from 1 to 20:0.4 to 2 or 3 to 4:1.

in some embodiments, the fumed silica has a particle size of 10 to 20nm or 15nm.

In some embodiments, the KH-540 is mixed with 1H, 2H-perfluorodecyl trimethoxysilane, then absolute ethanol is added as a solvent, and after thorough mixing, water is added.

In some embodiments, KH-540 is reacted with 1H, 2H-perfluorodecyl trimethoxysilane at 60-70℃for 3-4 hours.

In some embodiments, F-HP-Si is added to absolute ethanol and subjected to ultrasonic vibration for 10-15 minutes to uniformly disperse the F-HP-Si.

In some embodiments, the specific conditions for heating and mechanically agitating are: heating to 60-70 ℃ and stirring for 1.5-2 hours.

The invention will now be described in further detail with reference to the following specific examples, which should be construed as illustrative rather than limiting.

In the following examples, 3-aminopropyl trimethoxysilane (KH-540) and fumed Silica (SiO) ₂ Diameter of: 15 nm) from Ama Ding Huaxue reagent (Shanghai) Inc. (China).

1H, 2H-perfluorodecyl trimethoxysilane (FAS) is supplied by Thai Fu God of Jinan.

Sodium chloride, sodium hydroxide, hydrochloric acid, ethyl acetate, N-dimethylformamide, absolute ethyl alcohol, and acetone were all purchased from national pharmaceutical group chemical reagent company (China).

Wood board, ceramic, cotton fabrics were purchased from local shops. All chemicals were analytical grade and used without further purification.

By SUPRA operating at 5kV ^TM The surface morphology of the coating was measured by a 55 thermal field emission scanning electron microscope (SEM, germany).

The static contact angle of a 6 μl droplet was performed on the kruss DSA25S (germany) contact angle system and at least 3 different areas were used to obtain the average contact angle.

Example 1

1) Synthesis of fluorine-rich hyperbranched polysiloxane (F-HP-Si)

9g of 3-aminopropyl trimethoxysilane (KH-540) was taken in a laboratory environment into a clean 100mL round bottom flask containing a magneton, and 3g of 1H, 2H-perfluoro decyl trimethoxysilane was added thereto. Then 10mL of absolute ethanol was added as solvent, and after thorough mixing, 1mL of H was added ₂ O. After the medicine is added, the round bottom flask is placed in a magnetic stirrer with constant temperature of 60 ℃ for 4 hours, and finally transparent viscous liquid is obtained.

2) Preparation of transparent superhydrophobic coating

0.3g of F-HP-Si was taken separately in a round-bottomed flask with a magnet and sonicated with 30mL absolute ethanol using a pipette for 10 minutes. The flask after the ultrasonic treatment was taken out, and 0.05g, 0.08g, 0.1g, 0.15g, 0.2g of 15nm fumed silica was added thereto and sufficiently shaken for 20 minutes. The flask after the completion of the shaking was taken out and placed in a magnetic stirrer with constant temperature of 60℃for 2 hours to obtain a uniform dispersion.

The prepared solution was poured into a spray gun, the spray gun was set at a distance of 20cm from the glass substrate, and the spray was repeatedly conducted from left to right at a speed of 6cm/s for 20 times. After the spraying is finished, the sample is put into a constant temperature oven at 100 ℃ for 12 hours to obtain the super-hydrophobic surface.

F-HP-Si was quantified (0.3 g), and the WCA and transmittance curves with 15nm fumed silica are shown in FIG. 1. From this, it was found that addition of 0.1g of 15nm fumed silica can ensure that the superhydrophobic effect is achieved while maintaining good transmittance.

Example 2

1) Synthesis of fluorine-rich hyperbranched polysiloxane (F-HP-Si)

9g of 3-aminopropyl trimethoxysilane (KH-540) was taken in a laboratory environment into a clean 100mL round bottom flask containing a magneton, and then directed to3g of 1H, 2H-perfluorodecyl trimethoxysilane are added. Then 10mL of absolute ethanol was added as solvent, and after thorough mixing, 1mL of H was added ₂ O. After the medicine is added, the round bottom flask is placed in a magnetic stirrer with constant temperature of 60 ℃ for 4 hours, and finally transparent viscous liquid is obtained.

2) Preparation of transparent superhydrophobic coating

0.1g, 0.3g, 0.5g, 1.0g, 2.0g F-HP-Si were placed in a magnetic round bottom flask, respectively, and 30mL absolute ethanol was added to the flask by a pipette and sonicated for 10 minutes. The flask after the ultrasonic treatment was taken out, and 0.1g of 15nm fumed silica was added thereto and sufficiently shaken for 20 minutes. The flask after the completion of the shaking was taken out and placed in a magnetic stirrer with constant temperature of 60℃for 2 hours to obtain a uniform dispersion.

The 15nm fumed silica is quantitative (0.1 g), the curve of WCA and transmittance with F-HP-Si is shown in FIG. 2, and when the 15nm fumed silica is quantitative to 0.1g, the abscissa of the highest point of the contact angle is approximately between 0.3 and 0.4, and the contact angle between 0.2 and 1.0 does not change much. The present invention finally fixes the amount of F-HP-Si at 0.3g by combining the variations in the transmittance of the different samples.

Example 3

1) Synthesis of fluorine-rich hyperbranched polysiloxane (F-HP-Si)

2) Preparation of transparent superhydrophobic coating

0.3g of F-HP-Si was taken separately in a round-bottomed flask with a magnet and sonicated with 30mL absolute ethanol using a pipette for 10 minutes. The flask after the ultrasonic treatment was taken out, and 0.1g of 15nm fumed silica was added thereto and sufficiently shaken for 20 minutes. The flask after the completion of the shaking was taken out and placed in a magnetic stirrer with constant temperature of 60℃for 2 hours to obtain a uniform dispersion.

The prepared solution was poured into a spray gun, and the spray gun was moved from 20cm away from the glass substrate, and the spray was repeated 2, 5, 10, 15, and 20 times at a speed of 6cm/s from left to right. After the spraying is finished, the sample is put into a constant temperature oven at 100 ℃ for 12 hours to obtain the super-hydrophobic surface.

The influence of different spraying layers on hydrophobicity and transmittance is shown in figure 3, when the number of spraying layers reaches 20, the contact angle of the surface of the substrate is about 160 degrees, the effect of superhydrophobicity is achieved, and the transmittance of the modified glass is maintained at 72%. This shows that the hydrophobicity and transmittance of the coated glass are well balanced.

Experimental example 1

The performance test was performed using the sample sprayed 20 times in example 3 as an experimental sample. To observe the surface morphology on the coated glass sheet, SEM testing was performed on the coated glass sheet. In addition, EDS tests were performed on the modified glass panels in order to detect the distribution of the elements on the surface of the coated glass panels.

FIG. 4 is a SEM image at various scales showing the roughness of the coated glass sheet, nano SiO under the action of F-HP-Si binder ₂ The particles are densely packed on the surface of the substrate. This provides a basis for the stability and durability of the superhydrophobic properties while providing sufficient roughness.

As shown in fig. 5, the surface element distribution of the coated glass sample was C, N, O, F, si. The distribution of the elements is relatively uniform, and a situation that a certain element is stacked in a large amount does not occur. In addition, the presence of these elements may also prove that the glass was successfully modified.

Fig. 6 is a graph of a hydrophobicity test of a modified glass plate, wherein the contact angle of water is up to 162 ° and the roll angle is 3.1 °. It can be seen in conjunction with fig. 6 that the modified glass sheet has superhydrophobic properties. In addition, the lower rolling angle of the coated glass provides a basis for the self-cleaning performance of the super-hydrophobic material.

Experimental example 2

The sample sprayed 20 times in example 3 was used as an experimental sample, the modified glass plate was immersed in water, ethyl acetate, ethanol, naOH, naCl, acetone, HCl and DMF, respectively, and the modified glass plate was taken out of the immersed solution every 5 hours, washed with pure water, dried, and then measured for contact angle. After the measurement, the modified glass plate is placed into each solution to be soaked continuously.

As can be seen from the bar graph in FIG. 7, 8 parts of the modified glass plate always maintains the superhydrophobic property after 30 hours of high-strength soaking. Over time, the contact angle of most modified glass sheets decreased slightly, indicating that the experimentally prepared coated glass sheets had very high acid-base environmental resistance. Where sodium hydroxide has a greater effect on the sample surface, this may be related to corrosion of the silica by alkaline substances and damage to the silica bonds. However, the whole modified glass plate maintains the super-hydrophobic property, which means that the modified glass plate can maintain the super-hydrophobic property even under extreme environments.

Experimental example 3

The transmittance of both glass plates (modified and unmodified) was measured. The transmittance of the modified glass (20 times sprayed sample in example 3) and the transmittance of the unmodified glass are compared in the wavelength range of 300nm-800 nm. As shown in fig. 8, the transmittance of the modified glass at 600nm wavelength can reach 72%, and the modified glass also has relatively good transmittance compared with the common glass.

Experimental example 4

With the sample sprayed 20 times in example 3 as an experimental sample, particles were distributed on the inclined coating surface, a test droplet was dropped on the inclined coating surface, and it was observed whether the droplet could remove the particles on the coating surface during the movement without leaving marks. When the liquid removes all particles from the surface of the coating and restores the cleanliness of the surface, it is shown to have a self-cleaning effect.

As shown in fig. 9, the invention simulates a laboratory environment to perform self-cleaning experiments by using the novel super-hydrophobic coating, and makes multiple attempts, thereby having good self-cleaning effect on common dust and dust in life. This is mainly achieved based on the modification of the glass plate surface by the fluorine-rich hyperbranched polysiloxane (F-HP-Si) after the combination of 3-aminopropyl trimethoxysilane (KH-540) and 1H,2H, H-perfluoro decyl trimethoxysilane (FAS) and the construction of the surface roughness of the glass plate by fumed silica. By virtue of good superhydrophobic performance, transparency and durability, the transparent superhydrophobic coating can provide good self-cleaning capability for lenses of experimental instruments on the premise of not influencing transmittance.

Experimental example 5

The sample sprayed 20 times in example 3 was used as an experimental sample to test the hydrophobic effect of the superhydrophobic coating using other substrates

FIG. 10 is a modified substance sprayed with a superhydrophobic material on a different substrate. As can be seen from fig. 10, the modified wood board, the steel plate, the ceramic and the cotton cloth are compared with the unmodified one, wherein the modified base has superhydrophobic phenomenon. As shown in fig. a, the contact angle of the modified wood board is 155 ° on average, and the contact angle of the unmodified wood board is 40 ° within 10s due to the characteristic of water penetration. Therefore, the super-hydrophobic material prepared by the invention can be embodied on different substrates and has wide application capability.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The preparation method of the transparent super-hydrophobic coating is characterized by comprising the following steps of: uniformly mixing KH-540 and 1H, 2H-perfluoro decyl trimethoxy silane in a solvent, and heating to react to obtain F-HP-Si;

adding F-HP-Si into absolute ethyl alcohol, carrying out ultrasonic oscillation for 10-15 minutes to enable the F-HP-Si to be dispersed uniformly, adding fumed silica, fully oscillating, heating and carrying out mechanical stirring to obtain a dispersion liquid;

loading the dispersion liquid on a substrate material, and drying to obtain the composite material;

the mass ratio of KH-540 to 1H, 2H-perfluoro decyl trimethoxy silane is 3:1;

the mass ratio of the F-HP-Si to the fumed silica is 3:1;

after KH-540 is mixed with 1H, 2H-perfluoro decyl trimethoxy silane, absolute ethyl alcohol is firstly added as a solvent, and after full mixing, water is added;

KH-540 and 1H, 2H-perfluoro decyl trimethoxy silane react for 3-4 hours at 60-70 ℃;

the specific conditions of heating and mechanical stirring are heating to 60-70 ℃ and stirring for 1.5-2 hours;

the loading method is spraying, and the number of layers of spraying is 20;

the particle size of the fumed silica is 15nm.

2. The transparent superhydrophobic coating prepared by the method of claim 1.

3. Use of the transparent superhydrophobic coating of claim 2 in the field of dust protection, self-cleaning or corrosion protection.