阅读说明：本技术 一种提高可调控性的金属网络电极龟裂模板制备方法 (Preparation method of metal network electrode cracking template capable of improving controllability ) 是由 高进伟 尹钰鑫 李聪 于 2021-05-19 设计创作，主要内容包括：本发明公开了一种提高可调控性的金属网络电极龟裂模板制备方法,其步骤包括：将分散剂与液态的龟裂薄膜材料按比例混合,并使混合溶液中产生均匀的微小气泡；对透明衬底进行亲水性处理；将所述的混合溶液涂布于透明衬底上,使所述气泡均匀分布于所述透明衬底的表面,并进行干燥,形成龟裂模板。该方法能提高龟裂模板形成的路径与大小的可调控性,从而适应不同的应用场景。(The invention discloses a preparation method of a metal network electrode cracking template for improving controllability, which comprises the following steps: mixing a dispersing agent and a liquid cracking film material in proportion, and generating uniform micro bubbles in a mixed solution; carrying out hydrophilic treatment on the transparent substrate; and coating the mixed solution on a transparent substrate to uniformly distribute the bubbles on the surface of the transparent substrate, and drying to form a cracking template. The method can improve the adjustability of the path and the size formed by the cracking template, thereby being suitable for different application scenes.)

1. A preparation method of a metal network electrode cracking template for improving controllability is characterized by comprising the following steps:

mixing a dispersing agent and a liquid cracking film material in proportion, and generating uniform micro bubbles in a mixed solution; carrying out hydrophilic treatment on the transparent substrate; and coating the mixed solution on a transparent substrate to uniformly distribute the bubbles on the surface of the transparent substrate, and drying to form a cracking template.

2. The method for preparing the metal network electrode cracking template with the improved controllability according to claim 1, wherein the dispersing agent is selected from a PVA solution, a nano-silica solution, a sodium polyacrylate solution or a sodium methylene dinaphthalenesulfonate solution.

3. The method for preparing the metal network electrode cracking template with the improved controllability according to claim 2, wherein the dispersing agent is a PVA solution with a mass concentration of 2.5%.

4. The method for preparing the metal network electrode cracking template with improved controllability according to claim 2, wherein the cracking thin film material is selected from TiO₂At least one of sol, egg white sol, nail polish and cellulose.

5. The method for preparing the metal network electrode cracking template with the improved controllability according to claim 4, wherein the cracking thin film material is egg white sol.

6. The method for preparing the metal network electrode cracking template with the improved controllability according to any one of claims 2 to 5, wherein the mixing ratio of the dispersing agent to the cracking thin film material is 1: 2, 1: 3, 1: 4, 1: 5 or 1: 6 in volume ratio.

7. The method for preparing the metal network electrode cracking template with the improved controllability according to claim 6, wherein the uniform bubble generation mode comprises shaking, stirring or ultrasonic treatment.

8. The method for preparing the metal network electrode cracking template with the improved controllability according to claim 6, wherein the material of the transparent substrate comprises glass, PET, PC, PVC or PP.

9. The method for preparing the metal network electrode cracking template with improved controllability according to claim 6, wherein the hydrophilic treatment is cleaning for 50-100 s by using a plasma cleaning machine, and the power of the plasma cleaning machine is selected to be 180-220 w.

10. The method for preparing the metal network electrode cracking template with improved controllability according to claim 6, wherein the drying is performed in a manner including but not limited to natural drying cracking, heating by a heating table and the like, which can accelerate drying cracking.

Technical Field

The invention belongs to the technical field of transparent conductive films, and particularly relates to a preparation method of a metal network electrode cracking template for improving controllability.

Background

The cracking template is an important technology applied to the field of transparent conductive films: when the film material is subjected to thermal or mechanical stress, the accumulated stress can crack the film. Within some materials, these crack gaps can form a continuous network. By utilizing the phenomenon, metal is deposited into the cracks through magnetron sputtering, and finally the cracking template is removed, so that the submicron metal network transparent conductive electrode can be obtained.

The preparation process of the process mainly comprises four steps: (1) crack/sacrificial layer (commonly TiO)₂Epoxy, nail polish or egg white, etc.); (2) drying and cracking; (3) metal film deposition (magnetron sputtering, thermal evaporation or electroplating); and (4) removal of the cracked template.

Regular metal grids and random metal grids obtained by a cracking template method are a new generation of transparent conductive electrodes. In such an electrode, electrons are effectively collected by the metal mesh and the metal wires, and at the same time, the gaps between the metal wires can also achieve high light transmittance because the electrode performance is higher than that of a general electrode.

The metal grids and the metal wires are usually obtained by deposition of silver wires or copper wires and metal deposition on a fractal template, and common process methods comprise a photoetching template, a micro-nano imprinting template, a random cracking template, a vein template and the like. These metal grids can be deposited on flexible substrate materials as transparent conductive electrodes, suitable for flexible optoelectronic devices and equipment. The transparent conductive electrode prepared by the template method does not need high vacuum condition, and is suitable for the liquid phase method process with lower cost.

Taking the photolithography template method as an example, the key to prepare the metal grid is the periodically arranged micron or submicron template structure on the transparent substrate material (such as hard glass or flexible plastic), and the most common template structure is PS beads: the surface of the substrate is coated with a layer of precursor liquid in a spinning mode, the PS pellets can be self-assembled to form a two-dimensional close-packed hexagonal array, and the line width and the line spacing of the metal grids can be effectively adjusted and controlled by changing the diameter and the type of the PS pellets.

Maurer et al used direct nanoimprint method, PDMS as imprint template, Au nanowire ink as to-be-pressed colloid substrate, to obtain a transparent conductive electrode with sheet resistance less than 29 Ω/sq, and the light transmittance of the electrode can be adjusted by changing the concentration of nanowire ink and the geometric structure size of the stamp.

Wang et al prepared a large-area Ag mesh transparent electrode with a sheet resistance of 22.1 omega/sq and a light transmittance of 82% on a PET substrate by a Roll-to-Roll ultraviolet nanoimprint method (R2R UV-NIL) and using metal Ni as an imprint template.

Compared with photolithography and imprinting, the crack template is more and more concerned by the industry due to its advantages of low cost and simple operation of liquid phase method.

However, the randomness of cracking results in the randomness of the cracking template, and the cracking template meeting the requirements of various applications cannot be obtained. On the other hand, the size of the cracking block limits the application of the metal network transparent conductive electrode based on the cracking template, so that the metal network transparent conductive electrode cannot be suitable for application scenes needing high resolution.

Disclosure of Invention

The invention aims to provide a preparation method of a metal network electrode cracking template with improved controllability, which can improve the controllability of a path and a size formed by the cracking template so as to adapt to different application scenes.

The purpose of the invention is realized by the following technical scheme:

a preparation method of a metal network electrode cracking template for improving controllability comprises the following steps:

mixing a dispersing agent and a liquid cracking film material in proportion, and generating uniform micro bubbles in a mixed solution; carrying out hydrophilic treatment on the transparent substrate; and coating the mixed solution on a transparent substrate to uniformly distribute the bubbles on the surface of the transparent substrate, and drying to form a cracking template.

In the preparation method of the invention:

the dispersing agent includes but is not limited to PVA (polyvinyl alcohol), nano silicon dioxide, sodium polyacrylate or methylene dinaphthalene sodium sulfonate and the like, and other dispersing agents with similar dispersing performance can be applied to the preparation method. Preferably, the dispersing agent is a PVA solution with the mass concentration of 2.5%. The advantage of choosing PVA as a dispersant is that it is readily available, low cost and biodegradable relative to other dispersants.

The cracked film material includes but is not limited to TiO₂At least one of sol, egg white sol, nail polish and cellulose.

The mixing ratio of the dispersant to the cracked film material may preferably be 1: 2, 1: 3, 1: 4, 1: 5 or 1: 6 in volume ratio.

The means for generating uniform bubbles include, but are not limited to, shaking, stirring, or sonication.

The material of the transparent substrate includes, but is not limited to, glass, PET, PC, PVC, or PP.

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 selected to be 180-220 w.

The drying may be performed in a manner including, but not limited to, natural drying cracks, heating of a heating table, and the like, which may accelerate drying of the cracks.

The principle of the invention is as follows: after a dispersing agent and a cracking film material are mixed to form a mixed solution, small bubbles are generated in the solution in a shaking/stirring/ultrasonic processing mode and are uniformly distributed in the mixed solution under the action of the dispersing agent; then, carrying out plasma bombardment on the transparent substrate to increase the adhesion of the mixed solution and the substrate; and coating the mixed solution on the surface of the treated transparent substrate, finally placing the sample on a heating table for heating and drying, wherein the mixed solution is heated in the air to lose moisture and shrink, so that stress concentration is generated, and cracks are generated. In the process, because the dense small bubbles are uniformly distributed on the surface of the transparent substrate, a plurality of tiny defects are formed to form cracking centers, the cracking paths and sizes are influenced by the phenomenon, the positions forming the cracking centers are mutually connected to form cracks, and different proportions of the dispersing agent and the cracking film material can cause different cracking sizes. Therefore, the method can induce and regulate the generation of the cracks, thereby obtaining the crack template with finer and denser grains. On the other hand, through experimental comparison, the proportion of the dispersing agent to the cracking film material is controlled, so that micro-bubbles with different sizes and densities can be obtained, and the controllability of cracking is realized.

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

the invention mixes the dispersing agent and the cracking film material, generates uniformly distributed tiny bubbles in the mixed solution in a shaking/stirring/ultrasonic processing mode, then coats the tiny bubbles on the transparent substrate to prepare the cracking template, and controls the size and the density of the bubbles by adjusting the proportion between the dispersing agent and the cracking film material, thereby inducing and controlling the path and the size formed by the cracking template, reducing the randomness generated by the cracking template, realizing the adjustable operation of the preparation of the cracking template, and the prepared cracking template can be applied to the preparation process of submicron metal network electrodes, so that the preparation method can adapt to various application scenes.

Drawings

The invention is further illustrated by the following figures.

FIG. 1 example 1A flow chart of a method for preparing a cracking template.

Figure 2 picture of crack template preparation at 5 x magnification under optical microscope.

Figure 3 picture of crack template preparation at 20 x magnification under optical microscope.

Figure 4 picture of crack template prepared in comparative example 1 at 5 x magnification under optical microscope.

Figure 5 picture of crack template preparation at 5 x magnification under optical microscope.

Figure 6 picture of crack template preparation at 5 x magnification under optical microscope.

Figure 7 picture of crack template preparation at 5 x magnification under optical microscope.

Figure 8 picture of crack template preparation at 5 x magnification under optical microscope.

Figure 9 picture of crack template preparation at 40 x magnification under optical microscope.

Detailed Description

The present invention will be further described with reference to the following specific examples.

The egg white sol used in the embodiment of the invention is commercially available oform, and the component of the egg white sol is pure egg white; the PVA powder used is a commercially available PVA powder, the alcoholysis degree is 98-99%, and the viscosity is 27-34 mPas.

The specific process for preparing the cracking template in the embodiment of the invention is as follows:

preparation of PVA solution: 100g of deionized water was added to a beaker, followed by 2.5g of PVA powder and water, and the beaker was then placed on a heating table and stirred at a rate of 400r/min and a temperature of 150 ℃. After 10min, the temperature is reduced to 80 ℃ and stirring is continued for 40min to obtain a 2.5 percent PVA solution.

Examples

(1) Adding a cracking film material into the centrifugal tube, adding a dispersing agent, covering a cover, shaking up and down, and removing upper-layer floating foam to form a mixed solution in which micro bubbles are uniformly distributed;

(2) placing the transparent substrate in a plasma cleaning machine for hydrophilic treatment, wherein the cleaning time is 50-100 s in the process, and the power of the plasma cleaning machine is 180-220 w;

(3) and (3) coating the mixed solution prepared in the step (1) on the surface of the transparent substrate treated in the step (2), uniformly distributing micro bubbles on the transparent substrate, and then placing the transparent substrate on a heating table to heat at 75 ℃ for 10min to form a cracking template.

Fig. 1 is a schematic diagram of the process for preparing the cracking template in example 1.

Comparative example

(1) Adding a cracking film material into the centrifugal tube, covering the centrifugal tube with a cover, shaking up and down, and removing upper-layer floating foam to form a mixed solution in which micro bubbles are uniformly distributed;

(2) placing the transparent substrate in a plasma cleaning machine for hydrophilic treatment, wherein the cleaning time is 50-100 s in the process, and the power of the plasma cleaning machine is 180-220 w;

(3) and (3) coating the mixed solution prepared in the step (1) on the surface of the transparent substrate treated in the step (2), uniformly distributing micro bubbles on the transparent substrate, and then placing the transparent substrate on a heating table to heat at 75 ℃ for 10min to form a cracking template.

The details of the examples of the present invention and the comparative examples are shown in the following Table-1:

TABLE-1

The line segments in the attached fig. 2-9 of the invention represent the width of the crack lines/the distance between two crack lines.

As shown in fig. 2, the crack template prepared in example 1 is visible under 5 times magnification, the surface of the crack template is formed with crack centers caused by micro-bubbles, the size is large, the distribution is sparse, and the distance between crack lines in the pattern is 47.147 μm; as shown in fig. 3, the crack center induced crack generation caused by the formation of the micro-bubbles can be clearly seen under the magnification of 20 times, and it can be seen that the width of the crack lines is 2.495 μm, and the distance between the crack lines is 57.317 μm.

As shown in fig. 4, the crack template prepared in comparative example 1 was observed at 5 times magnification, and the surface had no crack centers formed, and the distance between crack lines was 507.092 μm.

As shown in fig. 5, the crack template obtained in example 2 was enlarged by 5 times, and the crack centers due to the micro-bubbles were formed on the surface of the template, so that the size of the crack template was large and the crack pattern was sparsely distributed, and the distance between the crack lines was 32.719 μm.

As shown in fig. 6, the crack template obtained in example 3 was enlarged 5 times, and crack centers due to micro-bubbles were formed on the surface of the template, so that the size of the crack template was large and the crack pattern was sparsely distributed, and the distances between the crack lines in the crack template were 45.482 μm and 82.744 μm.

As shown in fig. 7, the crack template obtained in example 4 is enlarged by 5 times, and the crack centers caused by the micro-bubbles are formed on the surface of the crack template, so that the size of the crack template is small, the crack template is densely distributed, and the distances among the crack lines are 45.672 μm, 22.339 μm and 33.220 μm.

As shown in fig. 8, the crack template prepared in example 5 is visible under 5 times magnification, the surface of the crack template is formed with crack centers caused by micro-bubbles, the size is small, the distribution is very dense, and the distance between crack lines in the figure is 24.905 μm; as shown in fig. 9, the generation of crack induced by crack centers formed by fine bubbles was clearly seen at 40 times magnification, and the width of crack lines was 0.988 μm.

It should be noted that the above-mentioned embodiments are only illustrative and not restrictive, and any modifications or changes within the meaning and range of equivalents to the technical solutions of the present invention by those skilled in the art should be considered to be included in the protection scope of the present invention.