CN115132423A - A controllable preparation method of crack template - Google Patents

Abstract

The invention discloses a preparation method of an adjustable cracking template, which is characterized in that egg yolk liquid is added into egg white liquid to prepare cracking liquid; and cleaning and carrying out hydrophilic treatment on the transparent substrate, then coating the cracking liquid on the treated transparent substrate by blade, and heating and drying to form the cracking template. The invention adjusts and controls the width of the cracking block by adjusting and controlling the cracking liquid (egg white liquid and yolk liquid), and obtains the cracking template which is smaller than the cracking block prepared by the existing egg white liquid. And the width of the cracking blocks can be further controlled by regulating the amount of the added egg yolk liquid, so that the performance of the transparent conductive electrode manufactured by using the cracking template is improved.

Description

A controllable preparation method of crack template

technical field

The invention belongs to the technical field of transparent conductive electrodes, and in particular relates to a method for preparing a controllable crack template.

Background technique

Transparent conductive electrodes (TCEs) are widely used in various optoelectronic devices, such as touch displays, solar cells, Light Emitting Diodes (LEDs), electromagnetic shielding, transparent heaters, smart windows and electronic skins, etc. .

At present, Indium Tin Oxide (ITO) is a commonly used transparent electrode material, but due to its own brittleness, scarcity of raw material indium, high cost, and complicated preparation process, ITO electrodes cannot adapt to the next generation of flexible electrodes. Development of optoelectronic devices. Therefore, in recent years, researchers have proposed a variety of new flexible materials to replace ITO, such as conductive polymer films, graphene films, metal nanowires, and metal networks.

Among them, metal network usually has low resistance, good bending resistance, optical transmittance and resistivity can be adjusted independently, and is considered to be a new generation of transparent electrode materials with the most development potential. The inventor has been conducting research on the preparation of metal network transparent electrodes by the crack template method since 2010. Cracking, also known as network cracking, is a phenomenon in which cracks and cracks are connected to form a network by heating the cracking fluid, and the stress distribution is uneven. It is common in life and nature. The existing process for preparing submicron metal network transparent electrodes by crack template method includes four steps: 1. Synthesize and deposit template/sacrificial layer; 2. Dry cracks to obtain crack templates; 3. Metal thin film deposition (sputtering) , thermal evaporation or electroplating); 4. Removal of the final crack template; the above-mentioned template/sacrificial layer is made of TiO ₂ , epoxy resin, nail polish or egg white liquid, wherein the egg white liquid is mainly protein, which can It forms a good film, and is green, pollution-free and easy to clean, so it is an excellent material for preparing template/sacrificial layers. Because the crack material used in the above crack template method is simple and easy to obtain, the technology is mature, green and environmentally friendly, and the cost is low, the photolithography technology is not involved in the process, the transparent electrode of the crack template has no periodic distribution, and there is no optical diffraction phenomenon. Without Moiré fringes, the Murray interference phenomenon of the regular metal network is completely solved, so the metal network transparent electrode prepared by the crack template method has a good application prospect.

However, the cracked template prepared in the prior art has the problem that the width of the cracked block is too large, and the cracked template also has the problem that the width of the cracked block varies in size due to the randomness of the cracks, that is, the width of the cracked block is different. The uniformity of the transparent conductive electrode is poor; the light transmittance and square resistance of the transparent conductive electrode are mainly affected by the width of the cracked block, so the above problems affect the photoelectric performance of the transparent conductive electrode, thus restricting the application of the crack template method. It cannot be used in the preparation of devices requiring higher carrier concentration, such as solar cells; in addition, when the existing crack template method is used to prepare transparent conductive electrodes for display and touch screens, the width of the crack block is relatively large. Large and uneven, there may be no metal lines between the display and touch pixel walls (100*100μm), and thus will not conduct. Moreover, the poor uniformity of the width of the cracked block also leads to uneven photoelectric properties of the produced transparent conductive electrodes, thereby reducing the product qualification rate and causing material and industrial waste.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method for preparing a controllable crack template, the width of the crack block in the crack template prepared by the method can be adjusted, and the width of the crack block is small.

The purpose of this invention is to realize through the following technical solutions:

A method for preparing a controllable crack template, comprising the following steps:

(1) adding the egg yolk liquid to the egg white liquid and fully mixing, so that it is evenly distributed in the egg white liquid to obtain a cracked liquid;

(2) Carry out cleaning treatment and hydrophilic treatment on the transparent substrate;

(3) Coating a cracking liquid on the surface of the transparent substrate to obtain a cracking film, and then drying the cracking film and naturally cracking to form a cracking template.

The ratio of the egg yolk liquid to the egg white liquid is 3.5-13g:1L.

The principle of the invention is as follows: first, the surface of the transparent substrate is cleaned and treated with hydrophilicity to improve the hydrophilicity of the substrate, and then the egg yolk liquid and the egg white liquid are fully mixed to obtain a cracking liquid, and the mixed cracking liquid is The liquid is coated on the surface of the transparent substrate and dried to form a crack template; during this process, due to the loss of moisture in the air by the cracking liquid, the film shrinks and produces stress concentration, resulting in cracks; the egg yolk will be uniform in tiny particles. Distributed in the egg white liquid, it and the egg white liquid are uniformly coated on the surface of the transparent substrate, which can significantly affect the size of the cracked block, resulting in a cracked template with a smaller crack block width than that without the addition of egg yolk liquid. As the proportion of egg yolk liquid in the cracked liquid increases, the width of the cracked block is smaller, and the controllable crack template is realized.

In the solution of the present invention, the ratio of the egg yolk liquid to the egg white liquid includes but is not limited to 3.5-13 g: 1 L, as long as the egg white liquid is added with the egg yolk liquid, the purpose of regulating the crack template can be achieved.

In a specific embodiment of the present invention, the material of the transparent substrate is selected from any material that can be used as a transparent substrate, such as glass, PET, PP, PVC, and PC.

The hydrophilic treatment is to use a plasma cleaning machine for cleaning for 50-100 s, and the power of the plasma cleaning machine is 180-220W.

In a preferred solution, the cleaning treatment specifically includes: ultrasonically cleaning the transparent substrate with detergent for 10-15 minutes, ultrasonic cleaning with ethanol for 10-15 minutes, ultrasonic cleaning with deionized water for 10-15 minutes, and then using It was blown dry with nitrogen; the power of the above ultrasonic was 100W.

In step (3), the method of coating the cracking liquid on the transparent substrate includes but is not limited to blade coating, slit coating and spin coating, etc. All methods that can realize the coating of the cracking liquid on the transparent substrate are all within the scope of the present invention.

The ways of cracking the cracking liquid in step (3) include natural drying cracking, heating drying cracking, vacuuming to accelerate cracking, and the like.

Preferably, in step (3), the cracked film is heated and dried at 60 to 70° C. for 7 to 10 minutes with a heating table, so that cracks occur to form a crack template.

Compared with the prior art, the present invention has the following beneficial effects:

(1) the present invention adopts the egg white liquid to prepare the crack template method on the basis of the existing, by regulating and controlling the crack liquid, that is, the egg yolk liquid of different proportions is evenly mixed in the egg white liquid, to control the size of the crack block in the crack template, And the cracked block width is smaller. Moreover, the crack block width in the crack template prepared by the method of the invention has better uniformity.

(2) The transparent conductive electrode produced by the crack template prepared by the method of the present invention can significantly reduce the square resistance on the basis of maintaining high light transmittance. Therefore, the method of the present invention expands the application of the crack template method, so that it can be used for preparing devices requiring higher carrier concentration and transparent conductive electrodes for display and touch screens.

(3) The egg white liquid and the egg yolk liquid adopted in the present invention are non-toxic, easy to obtain, green and pollution-free; the method of the present invention is simple in process, low in cost, and easy to realize industrialization.

Description of drawings

Fig. 1 is the controllable crack template preparation flow chart of the present invention;

FIG. 2 is a 5 times magnification image of the optical microscope of the crack template in Example 1. FIG.

FIG. 3 is an optical microscope 20 times magnification image of the crack template in Example 1. FIG.

FIG. 4 is a 5 times magnification image of the optical microscope of the crack template in Example 2. FIG.

FIG. 5 is a 20 times magnification image of the optical microscope of the crack template in Example 2. FIG.

FIG. 6 is a 5 times magnification image of the optical microscope of the crack template in Example 3. FIG.

FIG. 7 is an optical microscope 20 times magnification image of the crack template in Example 3. FIG.

FIG. 8 is a 5x magnification image of an optical microscope of a cracked template of Comparative Example 1, wherein a and b are images of two different fields of view.

FIG. 9 is a 20-fold magnification image of an optical microscope of a cracked template of Comparative Example 1, wherein c and d are images of two different fields of view.

Detailed ways

The present invention will be further described below through specific examples.

Example 1

As shown in Figure 1, a method for preparing a controllable crack template includes the following steps:

(1) adding 0.15g of egg yolk liquid to 40mL of egg white liquid, and by ultrasonic mixing, the egg yolk liquid is evenly distributed in the egg white liquid to obtain a cracked liquid;

(2) Using soda lime glass as the transparent substrate material, firstly carry out cleaning treatment: ultrasonic cleaning with detergent for 15 minutes, ultrasonic cleaning in ethanol for 15 minutes, ultrasonic cleaning in deionized water for 15 minutes, and drying with nitrogen gas;

Then conduct hydrophilic treatment: place it in a plasma cleaning machine for 60s, and the power of the plasma cleaning machine is 180-220W;

(3) Scratch the cracking liquid evenly on the treated soda-lime glass to obtain a cracked film, and then heat and dry at 60° C. for 8 minutes to crack the cracked film and form a crack template.

Test the prepared cracked template:

As shown in Figure 2, using an optical microscope to magnify 5 times for observation, it can be seen that the measured crack width is 57.177 μm; as shown in Figure 3, using an optical microscope to magnify 20 times for observation, you can see the measured The size of the crack line width is 1.246 μm; and as the size of the crack block width becomes smaller, the uniformity of the crack block width and crack line width is better.

Embodiment 2

The method of this embodiment is the same as that of the first embodiment, the difference is that the cracking liquid in this embodiment is 0.3 g of egg yolk liquid fully mixed into 40 mL of egg white liquid.

Detect the prepared crack template: as shown in Figure 4, the crack template after coating with crack liquid (egg white liquid plus 0.3g egg yolk liquid) and drying is magnified 5 times under an optical microscope, and the measurement can be seen. The width of the crack block is 38.01μm; Figure 5 is a 20x magnification under the optical microscope, it can be seen that the measured crack line width is 1.003μm; and as the size of the crack block width becomes smaller, the crack The uniformity of block width and crack line width is better.

Embodiment 3

The method of this embodiment is the same as that of Embodiment 1, except that the cracking liquid in this embodiment is 0.5 g of egg yolk liquid fully mixed into 40 mL of egg white liquid.

Detect the prepared crack template: as shown in Figure 6, the crack template after coating with crack liquid (egg white liquid plus 0.5g egg yolk liquid) and drying is magnified 5 times under an optical microscope, and the measurement can be seen. The width of the crack block is 30.751μm; Figure 7 is a 20x magnification under the optical microscope, it can be seen that the measured crack line width is 0.919μm; and as the size of the crack block width becomes smaller, the crack The uniformity of block width and crack line width is better.

Comparative Example 1

The method of the comparative example is the same as that of the first embodiment, the difference is that the cracked liquid of the comparative example is 40 mL of pure egg white liquid.

As shown in a and b in Figure 8, the crack template without egg yolk solution was observed by magnifying 5 times with an optical microscope. It can be seen that the uniformity of the crack block width is poor, and the measured crack block width The sizes are 148.101 μm, 151.888 μm, and 260.762 μm, respectively, and the width and size of the three cracked blocks are very different; as shown in c and d in Figure 9, the crack template without egg yolk solution was magnified 20 times for observation. , it can be seen that the measured crack line widths are 1.690 μm and 2.468 μm, respectively.

From the results of Examples 1 to 3 and Comparative Example 1 above, it can be seen that the cracked block in the cracked template with egg yolk solution is obviously smaller than that of the cracked template without egg yolk solution; When the proportion of medium egg yolk liquid increases, the width of the crack block is smaller, thus realizing the controllability of the crack template.

Further, transparent conductive electrodes were prepared by sputtering using the crack templates of Examples 1, 2 and Comparative Example 1, and the light transmittance and square resistance are shown in the following table.

Cracked template Transmittance(%) Square resistance (Ω/sq) Example 1 79.6 6 Embodiment 2 80.0 4 Comparative Example 1 86.3 40

It should be pointed out that the above embodiment is only a further description of the present invention, rather than a limitation. For example, in addition to lime soda glass, other inexpensive transparent substrate materials (PET, PC, PVC , PP, etc.), the amount of egg yolk liquid added in the egg white liquid is not limited to 0.15g, 0.3g, 0.5g of the above-mentioned embodiment, and the drying method can also adopt natural drying and vacuum drying; other specific parameter values are in the technical scheme. The object of the present invention can also be achieved within the scope of the present invention. Therefore, any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principle of the present invention should be equivalent substitutions, and are included in the protection scope of the present invention.

Claims (8)

1. a controllable crack template preparation method, is characterized in that, comprises the following steps: (1) adding the egg yolk liquid to the egg white liquid and fully mixing, so that it is evenly distributed in the egg white liquid to obtain a cracked liquid; (2) Carry out cleaning treatment and hydrophilic treatment on the transparent substrate; (3) Coating a cracking liquid on the surface of the transparent substrate to obtain a cracking film, and then drying the cracking film and naturally cracking to form a cracking template. 2 . The method for preparing a crack template according to claim 1 , wherein the ratio of the egg yolk liquid to the egg white liquid is 3.5-13 g: 1 L. 3 . 3. The method for preparing a crack template according to claim 1 or 2, wherein the material of the transparent substrate is selected from one of glass, PET, PP, PVC, and PC. 4. The method for preparing a crack template according to claim 1 or 2, wherein the hydrophilic treatment is to use a plasma cleaning machine to clean for 50-100 s, and the power of the plasma cleaning machine is 180-220W. 5. The method for preparing a crack template according to claim 1 or 2, wherein the cleaning treatment is: ultrasonically cleaning the transparent substrate with detergent for 10-15 minutes, and ultrasonic cleaning with ethanol for 10-15 minutes , ultrasonically cleaned with deionized water for 10 to 15 minutes, and then blown dry with nitrogen. 6. crack template preparation method according to claim 1 and 2 is characterized in that, in step (3), the method for coating crack liquid on transparent substrate is scraping coating, slit coating or spin coating . 7. The method for preparing a crack template according to claim 1 or 2, characterized in that, in step (3), the mode for cracking the cracking liquid comprises natural drying cracking, heating drying cracking and vacuuming to accelerate cracking. crack. 8 . The method for preparing a crack template according to claim 7 , wherein in step (3), the cracked film is heated and dried at 60 to 70° C. for 7 to 10 minutes with a heating table, so that cracks occur, Form a crack template.

Images