CN103570250B - A kind of preparation method of transparent hydrophobic glass - Google Patents

Abstract

The invention provides a method for preparing transparent super-hydrophobic glass. In the method, a polytetrafluoroethylene aqueous phase dispersion liquid is used to coat the glass surface, and a heat treatment process is adopted to solidify the coating film on the glass surface. The surface contact angle of the obtained glass is greater than 150°, has good transmittance to visible light, and the average light transmittance is greater than 50%. The process used in the method is simple, the raw materials are easy to obtain, the production efficiency is high, the cost is low, and the repeatability is good. The prepared glass has excellent superhydrophobicity and light transmission, and is suitable for glass curtain walls, glass windows, windshields, and glassware. And slides and other occasions.

Description

A kind of preparation method of transparent superhydrophobic glass

technical field

The invention relates to a preparation method of transparent super-hydrophobic glass, specifically a method for preparing transparent super-hydrophobic glass by utilizing polytetrafluoroethylene aqueous phase dispersion liquid and heat treatment.

Background technique

Superhydrophobic glass generally refers to coating a layer of superhydrophobic layer on the glass surface, so that the glass surface has low surface energy and super hydrophobic properties. The macroscopic performance is that the contact angle of water droplets on the glass surface is above 150°. In this way, the water droplets will not adhere to the glass surface and form a bead shape, and can roll off the glass under the action of its own gravity or a little external force. Superhydrophobic glass has unique self-cleaning and anti-fouling properties and has great application prospects in many fields.

Transparent superhydrophobic glass not only has super hydrophobic properties but also has high light transmittance. It can be used in glass curtain walls, glass windows, windshields and other occasions. It can quickly condense rainwater and snowwater into water droplets on the glass surface, quickly It rolls off and takes away surface pollutants at the same time, keeping the glass surface clean, thereby reducing the number of cleanings of glass curtain walls and glass windows, improving the visibility of windshields in rainy and snowy days, and improving economy and safety.

There are not many studies on the preparation of transparent superhydrophobic glass in the world, and there are few reports on related patents. So far, some documents have adopted the following preparation methods: (1) Fresnais et al. in "Surface and Coatings Technology" magazine 2006, 200, 5296-5305 It is reported that the method of plasma etching is used to treat low-density polyethylene on a glass substrate with O ₂ and CF ₄ plasma. When the microstructure size obtained is less than 50nm, the surface contact angle of the material is greater than 160°, because the scale of the microstructure is much smaller than that of visible light. wavelength, so the transparency of the obtained superhydrophobic glass is very good; (2) Wu et al. reported in "ChemicalVaporDeposition" magazine 2002, 8, 47-50 using microwave plasma enhanced chemical vapor deposition method, using argon as the carrier gas, Deposit the mixed gas of tetramethylsilane and fluorine-containing siloxane on the glass sheet, and change the roughness of the film by changing the time and pressure. When the surface microstructure scale is 11.3-60.8nm, the contact angle can reach 160° , and the resulting nanostructured surface has good transparency; (3) Tadanaga et al. reported in "ChemistryofMaterials" magazine 2000,12,590-592 that a transparent aluminum oxide film was prepared on a glass sheet by the method of gel sol, After the film is soaked in boiling water, dried and calcined, a rough surface with a petal-like structure can be obtained. By adjusting the process parameters, the surface unevenness scale can be controlled within the range of 20-50nm, and then transparent superhydrophobic glass can be obtained after modification with fluorosilicone; (4) Nakajima et al. in "ThinSolidFilms" magazine 2000, 376, 140- 143 reported that in the sol-gel system, the phase separation phenomenon of organic and inorganic phases was used, combined with the filling effect of colloidal _SiO2 particles on the glass substrate, to prepare hard superhydrophobic transparent glass.

The preparation methods listed above generally have complex process equipment, cumbersome preparation process, harsh operating conditions, high production cost and energy consumption, and low production efficiency, which limits their application.

Contents of the invention

The purpose of the present invention is to provide a simplified preparation method of transparent super-hydrophobic glass to solve the problems of cumbersome preparation process, low production efficiency and high production cost of transparent super-hydrophobic glass. The coating film is then cured on the glass surface by a heat treatment process to obtain a super-hydrophobic glass with a contact angle greater than 150° and good visible light transmission.

The technical solution of the present invention is: a preparation method of transparent superhydrophobic glass, which is characterized in that firstly adding polytetrafluoroethylene powder into water, fully stirring to make an aqueous phase dispersion, and then immersing the glass in polytetrafluoroethylene water In the phase dispersion liquid, use a pulling machine to slowly and uniformly extract it from the dispersion liquid, and after extraction, it will be heat-treated and solidified to obtain a transparent super-hydrophobic glass.

The particle size of the polytetrafluoroethylene powder used in the present invention is from 1 nanometer to 100 microns. If the particle size is too small, the polytetrafluoroethylene powder is easy to agglomerate. If the particle size is too large, the polytetrafluoroethylene powder is difficult to adhere to the surface of the glass. The preferred particle size is 2 nanometers to 50 microns.

On the surface of the aqueous polytetrafluoroethylene dispersion used in the present invention, the content of polytetrafluoroethylene is 3-50 g/m ² . If the amount of PTFE is too small, a relatively uniform film cannot be formed. If the amount is too large, it will easily cause waste and increase costs, and it will easily cause an increase in the thickness of the glass surface film, which will have a certain impact on the light transmittance of the surface. Water is preferred. The content of polytetrafluoroethylene on the surface of the phase dispersion liquid is 3.37-33.5g/m ² .

The pulling speed used in the present invention is 30-90mm/min. If the pulling speed is fast, defects are likely to appear on the glass surface, and if the pulling speed is slow, the production cycle will be longer and the production efficiency will be reduced. The preferred pulling speed is 50-75 mm/min.

The heat treatment temperature used in the present invention is 280-360°C. If the heat treatment temperature is high, it will easily cause the decomposition of polytetrafluoroethylene. If the heat treatment temperature is low, it will be unfavorable for the adhesion and curing of polytetrafluoroethylene on the glass surface. The preferred heat treatment temperature is 295-350°C. .

Compared with the prior art, the present invention has the advantages of:

(1) adopt the method of the present invention, process equipment is simple, repeatability is good, and raw material price is cheap, has obvious low-cost advantage;

(2) The transparent superhydrophobic glass prepared by the method of the present invention has a surface water contact angle greater than 150°, and water droplets are very easy to roll and slide off the surface and take away the dust on the surface to achieve self-cleaning function;

(3) The transparent superhydrophobic glass prepared by the method of the present invention has good visible light transmittance, and the average light transmittance is greater than 50%;

(4) The transparent superhydrophobic glass prepared by the inventive method can be used in occasions such as glass curtain walls, glass windows, windshields, glassware and glass slides.

Description of drawings

Fig. 1 is the scanning electron micrograph of the transparent superhydrophobic glass surface of embodiment 1 gained;

Fig. 2 is the transparent superhydrophobic glass surface water contact angle state diagram of embodiment 1 gained;

Fig. 3 is the scanning electron micrograph of the transparent superhydrophobic glass surface of embodiment 2 gained;

Fig. 4 is the transparent superhydrophobic glass surface water contact angle state diagram of embodiment 2 gained;

Fig. 5 is the transparent superhydrophobic glass surface water contact angle state diagram of embodiment 3 gained;

Fig. 6 is the transparent superhydrophobic glass surface water contact angle state diagram of embodiment 4 gained;

Fig. 7 is the transparent superhydrophobic glass surface water contact angle state diagram of embodiment 5 gained;

Fig. 8 is the transparent superhydrophobic glass surface water contact angle state diagram of embodiment 6 gained;

Figure 9 is a typical transparent super-hydrophobic glass to the visible light transmission effect diagram (a) of the color plate that comes with Microsoft Office and a comparison with the light transmission effect diagram (b) of ordinary glass.

Detailed ways

Below in conjunction with embodiment the present invention is described in further detail.

The scanning electron microscope photos were measured by JEOL JSM-6390 scanning electron microscope.

The contact angle data was measured by Chengde Dingsheng JY-82 contact angle meter.

Visible light transmittance was measured by Beijing General Analysis UV-1810 UV-Vis spectrometer.

Example 1

Add the polytetrafluoroethylene powder with a particle size of 10 microns into the water, stir well to make an aqueous dispersion with a surface polytetrafluoroethylene content of 20g/ ^m2 , and then immerse the glass in the polytetrafluoroethylene aqueous dispersion , extracted from the dispersion at a slow and uniform speed with a pulling machine at a pulling speed of 90mm/min, and then heat-treated at 360°C to obtain a transparent superhydrophobic glass. As shown in the scanning electron microscope photo of the glass surface in accompanying drawing 1, the glass surface has a certain roughness obtained from a particle structure of about 10 microns, and its water contact angle reaches 151° after heat treatment, as shown in accompanying drawing 2. Since the particle size of the glass surface is small, it will not cause too much scattering to visible light, and the measured average visible light transmittance of the glass is 72%, so the glass has good visible light transmittance.

Example 2

Add the polytetrafluoroethylene powder with a particle size of ²⁰⁰ nanometers into the water, stir well to make an aqueous dispersion with a surface polytetrafluoroethylene content of 3g/m2, and then immerse the glass in the polytetrafluoroethylene aqueous dispersion , pulled out from the dispersion liquid at a slow and uniform speed with a pulling machine at a pulling speed of 75mm/min, and then heat-treated at 350°C to obtain a transparent superhydrophobic glass. As shown in the scanning electron microscope photo of the glass surface in accompanying drawing 3, the glass surface has a certain roughness obtained by the particle structure of about 200 nanometers, and its water contact angle reaches 154° after heat treatment, as shown in accompanying drawing 4. Since the particle size of the glass surface is small, it will not cause too much scattering to visible light, and the measured average visible light transmittance of the glass coating is 75%, so the glass has good visible light transmittance.

Example 3

Add the polytetrafluoroethylene powder with a particle size of 100 microns into the water, stir well to make an aqueous dispersion with a surface polytetrafluoroethylene content of 50g/ ^m2 , and then immerse the glass in the polytetrafluoroethylene aqueous dispersion , extracted from the dispersion at a slow and uniform speed with a pulling machine at a pulling speed of 50mm/min, and then heat-treated at 320°C to obtain a transparent superhydrophobic glass. After heat treatment, its water contact angle reaches 153°, as shown in Figure 5. At the same time, the glass has good visible light transmittance, and the average visible light transmittance reaches 52%.

Example 4

Add the polytetrafluoroethylene powder with a particle size of ² nanometers into the water, stir well to make an aqueous dispersion with a surface polytetrafluoroethylene content of 25g/m2, and then immerse the glass in the aqueous polytetrafluoroethylene dispersion , extracted from the dispersion at a slow and uniform speed with a pulling machine at a pulling speed of 30mm/min, and then heat-treated at 295°C to obtain a transparent superhydrophobic glass. After heat treatment, its water contact angle reaches 150°, as shown in Figure 6. At the same time, the glass has good visible light transmittance, and the average visible light transmittance reaches 70%.

Example 5

Add polytetrafluoroethylene powder with a particle size of 50 microns into water, stir well to make an aqueous dispersion with a surface polytetrafluoroethylene content of 33.5g/ ^m2 , and then immerse the glass into the aqueous polytetrafluoroethylene dispersion In the above process, the dispersion liquid is slowly and uniformly extracted by a pulling machine, and the pulling speed is 60mm/min. After extraction, the transparent superhydrophobic glass is obtained after heat treatment at 320°C. After heat treatment, its water contact angle reaches 155°, as shown in Figure 7. At the same time, the glass has good visible light transmittance, and the average visible light transmittance reaches 68%.

Example 6

Add polytetrafluoroethylene powder with a particle size of 1 nanometer into water, stir well to make an aqueous dispersion with a surface polytetrafluoroethylene content of 3.37g/ ^m2 , and then immerse the glass in the polytetrafluoroethylene aqueous dispersion In the above process, it is slowly and uniformly extracted from the dispersion liquid with a pulling machine, and the pulling speed is 75mm/min. After being extracted, it is heat-treated at 280°C to obtain a transparent super-hydrophobic glass. After heat treatment, its water contact angle reaches 152°, as shown in Figure 8. At the same time, the glass has good visible light transmittance, and the average visible light transmittance reaches 73%.

Claims (2)

1. the preparation method of a transparent hydrophobic glass, it is characterized in that first polytetrafluoroethylpowder powder being added to the water, abundant stirring, make aqueous dispersion liquid, again glass is immersed in tetrafluoroethylene aqueous dispersion liquid, slowly at the uniform velocity propose from dispersion liquid with pulling machine, after proposition, after heat treatment namely obtain transparent hydrophobic glass;

Polytetrafluoroethylpowder powder particle diameter is 1 nanometer to 100 micron, and aqueous dispersion liquid surface polytetrafluoroethylene content is 3 ~ 50g/m ², pull rate is 30 ~ 90mm/min, and thermal treatment temp is 280 ~ 360 DEG C.

2. preparation method according to claim 1, is characterized in that Optimal technique process is: polytetrafluoroethylpowder powder particle diameter is 2nm ~ 50 μm, and aqueous dispersion liquid surface polytetrafluoroethylene content is 3.37 ~ 33.5g/m ², pull rate is 50 ~ 75mm/min, and thermal treatment temp is 295 ~ 350 DEG C.