阅读说明：本技术 一种柔性电致变色薄膜及其制备方法 (Flexible electrochromic film and preparation method thereof ) 是由 田艳红 张贺 王尚 吴炳英 于 2019-12-16 设计创作，主要内容包括：一种柔性电致变色薄膜及其制备方法,属于纳米技术领域。一种柔性电致变色薄膜,包括柔性基底、合金防护的铜纳米线层和电致变色层,所述合金防护的铜纳米线层涂覆在柔性基底的表面,所述电致变色层涂覆在合金防护的铜纳米线层的表面。本发明的优点是：通过电沉积合金防护层后,合金防护的铜纳米线可以大幅度提高电极的电化学稳定性,以其为基底可在表面电化学聚合电致变色层,获得柔性电致变色薄膜。(A flexible electrochromic film and a preparation method thereof belong to the field of nanotechnology. The utility model provides a flexible electrochromic film, includes flexible base, the copper nanowire layer and the electrochromic layer of alloy protection, the surface at flexible base is coated to the copper nanowire layer of alloy protection, the surface at the copper nanowire layer of alloy protection is coated to the electrochromic layer. The invention has the advantages that: after the alloy protective layer is electrodeposited, the electrochemical stability of the electrode can be greatly improved by the alloy-protected copper nanowires, and the flexible electrochromic film can be obtained by electrochemically polymerizing the electrochromic layer on the surface by taking the alloy-protected copper nanowires as a substrate.)

1. A flexible electrochromic film characterized in that: copper nanowire layer (2) and electrochromic layer (3) including flexible base (1), alloy protection, the surface at flexible base (1) is coated in copper nanowire layer (2) of alloy protection, the surface at copper nanowire layer (2) of alloy protection is coated in electrochromic layer (3).

2. A flexible electrochromic film according to claim 1, characterized in that: the copper nanowire layer (2) with the alloy protection comprises an alloy protection layer and copper nanowires, wherein the copper nanowires are coated on the flexible substrate (1), and the alloy protection layer is coated on the surface of the copper nanowires.

3. A flexible electrochromic film according to claim 2, characterized in that: the alloy protective layer comprises any two metals or alloy of a plurality of metals of gold, silver, platinum and palladium.

4. A flexible electrochromic film according to claim 1, characterized in that: the flexible substrate (1) is made of a flexible transparent high polymer material.

5. A flexible electrochromic film according to claim 4, characterized in that: the high polymer material comprises polyethylene terephthalate or polyimide.

6. A flexible electrochromic film according to claim 1, characterized in that: the electrochromic layer (2) comprises one or two of polyaniline and polythiophene.

7. A method for preparing a flexible electrochromic film according to any one of claims 1 to 6, characterized by comprising the steps of:

the method comprises the following steps: coating the copper nanowire ink on the surface of the flexible substrate (1) to obtain a copper nanowire flexible electrode;

step two: electrifying the graphite electrode serving as an anode and the copper nanowire flexible electrode prepared in the step one serving as a cathode to carry out electrodeposition in the alloy electrodeposition liquid to obtain an alloy-protected copper nanowire flexible electrode;

step three: and (3) taking the copper nanowire flexible electrode with the alloy protection obtained in the step two as a working electrode, a platinum sheet as a counter electrode and Ag/AgCl as reference, and electrochemically polymerizing the electrochromic layer (3) on the surface of the copper nanowire flexible electrode with the alloy protection in the electrochromic layer deposition solution to obtain the flexible electrochromic film.

8. The method for preparing a flexible electrochromic film according to claim 7, wherein: in the first step, the method for coating the copper nanowires on the flexible substrate (1) comprises a drop coating method, a meyer rod method, a spin coating method, a vacuum filtration method or a spraying method.

Technical Field

The invention belongs to the field of nanotechnology, and particularly relates to a flexible electrochromic film and a preparation method thereof.

Background

The electrochromic is a phenomenon that the optical property of the material is reversibly changed along with the change of an external electric field, has the advantages of quick response, good reversibility, good color memory and the like, and has been widely successful in the fields of intelligent windows, intelligent rearview mirrors, military camouflage and the like. The electrochromic glass can selectively change color under the regulation and control action of an electric field so as to realize absorption and reflection of sunlight, so that the indoor space is warmer in winter and cooler in summer, and the illumination energy consumption and the refrigeration energy consumption are effectively reduced. With the rise and development of wearable electronics and flexible electronics, the current electrochromic device also faces the development demand of more and more urgent flexibilization. Therefore, the search for a flexible transparent electrode material which can be bent is very important for preparing flexible electrochromic devices.

The traditional electrochromic device is mainly prepared on the basis of a hard Indium Tin Oxide (ITO) transparent electrode substrate, but the ITO material is extremely fragile, difficult to apply to a flexible electrochromic device, expensive in cost and low in indium storage capacity. The copper nanowire-based electrode has not only photoelectric properties comparable to ITO electrodes but also excellent flexibility, and thus is considered as the most potential next-generation flexible transparent electrode. However, the poor electrochemical stability limits the application of the copper nanowire flexible electrode in the field of electrochromism, and when the copper nanowire flexible electrode is used as an anode and an electrochromism layer is electrochemically polymerized on the surface of the copper nanowire flexible electrode, the copper nanowire flexible electrode is very easy to dissolve on the surface of the copper nanowire flexible electrode due to anodic oxidation and ionization, and loses conductivity, so that the protection of the copper nanowire flexible electrode to improve the electrochemical stability is very important.

Disclosure of Invention

The first purpose of the invention is to provide a flexible electrochromic film for overcoming the defect that a copper nanowire flexible electrode is difficult to apply in the electrochemical field, improving the electrochemical stability of the copper nanowire flexible electrode.

The second purpose of the invention is to provide a preparation method of the flexible electrochromic film.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the utility model provides a flexible electrochromic film, includes flexible base, the copper nanowire layer and the electrochromic layer of alloy protection, the surface at flexible base is coated to the copper nanowire layer of alloy protection, the surface at the copper nanowire layer of alloy protection is coated to the electrochromic layer.

Further, the copper nanowire layer of the alloy protection comprises an alloy protection layer and copper nanowires, the copper nanowires are coated on the flexible substrate, and the alloy protection layer is coated on the surface of the copper nanowires.

Further, the alloy protective layer comprises any two metals or an alloy of a plurality of metals of gold, silver, platinum and palladium.

Further, the flexible substrate is made of a flexible transparent high polymer material.

Further, the polymer material includes polyethylene terephthalate or polyimide.

Further, the electrochromic layer comprises one or two of polyaniline and polythiophene.

A preparation method of a flexible electrochromic film comprises the following steps:

the method comprises the following steps: coating the copper nanowire ink on the surface of the flexible substrate to obtain a copper nanowire flexible electrode;

step two: electrifying the graphite electrode serving as an anode and the copper nanowire flexible electrode prepared in the step one serving as a cathode to carry out electrodeposition in the alloy electrodeposition liquid to obtain an alloy-protected copper nanowire flexible electrode;

step three: and D, taking the copper nanowire flexible electrode with the alloy protection obtained in the step two as a working electrode, a platinum sheet as a counter electrode and Ag/AgCl as a reference, and electrochemically polymerizing the electrochromic layer on the surface of the copper nanowire flexible electrode with the alloy protection in the electrochromic layer deposition solution to obtain the flexible electrochromic film.

Further, the method for coating the copper nanowire on the flexible substrate comprises a drop coating method, a meyer bar method, a spin coating method, a vacuum filtration method or a spraying method.

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

(1) the alloy protective layer effectively improves the electrochemical stability of the copper nanowire flexible electrode, and improves the anodic oxidation resistance of the copper nanowire flexible electrode in the process of preparing the electrochromic film; (2) according to the invention, the alloy protective layer can effectively connect mutually stacked nanowires, so that the contact resistance is reduced; (3) in the invention, the alloy protective layer only grows on the surface of the nanowire, so that the influence on the light transmittance of the electrode is small.

Drawings

FIG. 1 is an electrochromic film structure prepared based on copper nanowire conductive films;

FIG. 2 is a scanning electron microscope image of a copper nanowire flexible electrode without alloy protection;

FIG. 3 is a scanning electron microscope image of a gold-silver alloy protected copper nanowire flexible electrode;

FIG. 4 is a scanning electron microscope image of an electrochromic film obtained after electrochemical polymerization of polyaniline on the surface of a copper nanowire flexible electrode without alloy protection;

FIG. 5 is a scanning electron microscope image of an electrochromic film obtained after electrochemical polymerization of polyaniline on the surface of a gold-silver alloy protected copper nanowire flexible electrode;

FIG. 6 shows the color of the electrochromic film at-0.2V;

FIG. 7 shows the color of the electrochromic film at 0.8V.

In the figure, 1, a flexible substrate, 2, a copper nanowire layer protected by an alloy, 3, an electrochromic layer.

Detailed Description

The technical solutions of the present invention are further described below with reference to fig. 1 to 7 and the embodiments, but not limited thereto, and modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.