阅读说明：本技术 一种穿插型复合结构电致变色薄膜的构筑思想和制备方法 (Construction idea and preparation method of alternating composite structure electrochromic film ) 是由 苏革 王文庆 谭淑君 汤晶 代国强 李正心 于知非 于 2020-08-03 设计创作，主要内容包括：本发明涉及一种穿插型复合结构电致变色薄膜的构筑思想和制备方法。首先,对导电基底进行表面清洁预处理,即将基底依次于蒸馏水,无水乙醇,丙酮,无水乙醇,蒸馏水中进行超声清洗10-30分钟；然后,在基底上构筑具有特殊微观结构的过渡层,过渡层微观结构可以为纳米棒状阵列结构、网络结构、多孔阵列结构、多级结构等或者其他结构,过渡层材料可以为氧化铟、氧化钛、氧化锌等或其他材料；最后,在过渡层上复合生长电致变色材料膜。通过电致变色层与过渡层微观结构上的穿插,构筑出穿插型复合结构电致变色薄膜。过渡层和电致变色材料膜通过水热法、溶剂热法、电沉积法等或者其他技术制备。通过过渡层材料的引入,可有效改善膜基界面结合状态,有效提升电荷传输效率,有效提升电致变色材料的使役性能。(The invention relates to a construction idea and a preparation method of an electrochromic film with an interpenetration type composite structure. Firstly, performing surface cleaning pretreatment on a conductive substrate, namely performing ultrasonic cleaning on the substrate in distilled water, absolute ethyl alcohol, acetone, absolute ethyl alcohol and distilled water for 10-30 minutes in sequence; then, a transition layer with a special microstructure is constructed on the substrate, the microstructure of the transition layer can be a nano rod-shaped array structure, a network structure, a porous array structure, a multilevel structure and the like or other structures, and the material of the transition layer can be indium oxide, titanium oxide, zinc oxide and the like or other materials; and finally, compositely growing an electrochromic material film on the transition layer. And the alternating composite structure electrochromic film is constructed by the alternating of the electrochromic layer and the transition layer microstructure. The transition layer and the electrochromic material film are prepared by a hydrothermal method, a solvothermal method, an electrodeposition method, or the like, or other techniques. By introducing the transition layer material, the film-substrate interface bonding state can be effectively improved, the charge transmission efficiency is effectively improved, and the service performance of the electrochromic material is effectively improved.)

1. The construction idea and preparation method of the interpenetrating composite structure electrochromic film are characterized in that a transition layer with a special structure is prepared on the surface of a substrate, the structure of the transition layer comprises a rod-shaped array, a network, a porous array, a multilevel structure and the like, and then an electrochromic material is compounded on the transition layer; the transition layer and the electrochromic material are mutually interpenetrated on the micro-morphology to form an interpenetration type composite structure, and all methods and technologies capable of preparing the film with the interpenetration type composite structure are applicable.

2. The method for constructing an interpenetrating composite structure electrochromic film as claimed in claim 1, wherein the properties and structure of the electrochromic film can be controlled by designing the properties and structure of the transition layer material.

3. The method for constructing an electrochromic film with an interpenetrating composite structure according to claim 1, wherein the transition layer is introduced to effectively improve the film-substrate bonding state, improve the porous structure, and increase the ion transmission rate, thereby improving the service performance of the electrochromic film.

Technical Field

The invention belongs to a construction idea and a preparation method of a functional film with a novel composite structure, and particularly relates to a method for constructing and preparing an electrochromic film with an interpenetration type composite structure.

Background

In the aspects of effectively utilizing solar energy and saving energy, the Electrochromic (EC) material and the device with the function of reversibly regulating and controlling the optical performance have outstanding advantages and become a research hotspot in the field of international energy-saving and emission-reducing materials.

The main reasons influencing the application of the electrochromic film comprise the aspects of non-ideal film-substrate bonding state, low discoloration rate, narrow discoloration range, slow discoloration response, poor service stability, short cycle life and the like. At present, electrochromic films of single structure (non-composite structure) have difficulty in achieving a compromise between structure and properties, often losing one another and other advantages while improving certain properties, resulting in poor service performance and therefore lack of room for further improvement and development. The composite structure becomes the most effective way to improve the performance of the electrochromic film. In recent years, electrochromic film research has been increasingly focused on composite structures, such as TiO/NiO and TiO₂/Ni(OH)₂Double-layer structure, NiO/ITO core-shell structure nano-particle film and the like. These studies have not only opened up new avenues for the study of electrochromic films, but also indicate that structural design and construction are critical in determining the enabling performance of composite electrochromic films. In fact, the structure of the composite film affects not only the performance, but also the bonding state between the film/substrate and the composite layer. How to perfectly solve the service problem of the electrochromic film through the structural design is important for the technical research and development of the composite electrochromic filmAnd (4) direction.

Research shows that the common composite film (see figure 1 a) formed by two (or more) polycrystalline films has no obvious effect on improving comprehensive performance, so that the invention provides a construction idea of an interpenetration type composite film in order to effectively improve the film-substrate combination state, improve the porous structure and improve the ion transmission rate so as to improve the comprehensive performance, and specifically comprises the following steps: a transition layer with a special structure is constructed between the substrate and the electrochromic film by selecting a material with excellent bonding performance with the substrate to form an interpenetrating structure composite film (see figure 1 b). The structural design realizes the subversion of the traditional composite membrane structure and is an ideal solution for the problems. The construction idea and the preparation technology of the variable optical parameter film with the special structure provide a potential technical approach for solving the problems of effective utilization of sunlight, rapid conversion of optical switch states, stealth/visible conversion of military facilities and the like of the facilities such as buildings, vehicles and the like, and have the advantages of military and civil integration and application.

Disclosure of Invention

The invention aims to provide a construction idea and a preparation method of an electrochromic film with an interpenetration type composite structure, and overcomes the defects of the existing electrochromic film structure and preparation technology. The present invention mainly includes the following three aspects.

1. Screening of transition layer materials

The transition layer material is selected according to the electrochromic material, the substrate material and the desired performance requirements. For example: nickel system (NiO and Ni (OH)₂) Or other electrochromic materials; FTO, ITO, organic conductive flexible transparent conductive films, or other substrates; changes in light transmittance in the near infrared region, the visible region, the near ultraviolet region, changes in color, and the like.

2. Construction of transition layer structures

And constructing a transition layer with a special microstructure on the surface of the substrate. The transition layer microstructure may be a nanorod array structure, a network structure, a porous array, a multilevel structure, or other structures.

3. Preparation of alternating composite structure electrochromic film

And (3) compositely growing an electrochromic layer on the surface of the transition layer with the special microstructure to form the electrochromic film with the interpenetration type composite structure. The purpose of controlling the performance and the structure of the electrochromic film is achieved by designing the performance and the structure of the transition layer material.

The technology adopted by the invention has low requirement on equipment, simple operation and lower cost, can prepare the interpenetration type composite structure electrochromic film with excellent structure and better service performance on the surface of the conductive substrate, and makes contribution to the further popularization and application of the electrochromic film material.

Drawings

FIG. 1 is a schematic diagram showing a structure comparison between a conventional composite film (a) and an interposed composite film (b).

FIG. 2 is a scanning electron micrograph of an electrochromic film with a transition layer and an interpenetrating composite structure prepared on the surface of FTO by using the composite film construction idea of the present invention. The pictures a and b are the surface appearances of the titanium dioxide nanorod array transition layer and the nickel oxide/titanium dioxide electrochromic film with the interpenetrating composite structure prepared by adopting a hydrothermal and solvent method; c and d are surface appearance and cross section photographs of the nickel hydroxide/titanium dioxide electrochromic film with the interpenetrating composite structure prepared by hydrothermal and solvothermal methods, and the growth of nickel hydroxide in gaps of the titanium dioxide nanorod array can be seen from the cross section photographs to form an interpenetrating structure; e and f are the surface appearances of the indium oxide nanorod array transition layer and the nickel hydroxide/indium oxide electrochromic film with the interpenetrating composite structure prepared by the hydrothermal and solvothermal methods; and the images g and h are the surface appearances of the zinc oxide nano rod array transition layer prepared by the electrodeposition technology and the nickel oxide/zinc oxide electrochromic film with the interpenetration type composite structure, and the nickel oxide can grow along the surface of the zinc oxide nano rod to form the interpenetration structure. The composite membrane is in a porous alternate structure, and is beneficial to improving the electrochromic effect.

FIG. 3 is a graph showing the transmittance change of an interpenetrating composite nickel hydroxide/titanium dioxide electrochromic film on the surface of an FTO prepared by using the composite film construction idea of the present invention. Therefore, the cycle life of the composite membrane can reach more than 11000 circles. When the light passes through the first 2500 circles, the light transmission change rate at the wavelength of 550nm reaches over 82 percent, and the light transmission change rate at the wavelength of 800nm exceeds 90 percent, so that no obvious attenuation exists. 11000 circles, the light transmission change rate at the wavelength of 550nm can still reach 35 percent, and the light transmission change rate at the wavelength of 800nm still exceeds 54 percent. The colored state is substantially close to 0 in the wavelength range of 300-800 nm. Embodies good recycling performance and has better near infrared region color changing performance.

Detailed Description

Firstly, the surface of a substrate is subjected to precleaning treatment, and the specific process comprises the following steps: ultrasonic cleaning the mixture in distilled water, absolute ethyl alcohol, acetone, absolute ethyl alcohol and distilled water for 10-30 minutes in sequence, drying and placing the mixture in a drying dish for later use.

The organic solvent N, N-Dimethylformamide (DMF) was dried over an activated 4A molecular sieve for 48 hours and then distilled under reduced pressure to remove a small amount of water contained therein. All the medicines used in the experiment are commercially available analytically pure.

1. Screening of transition layer materials

Since the structure and the structure of the transition layer material determine the structure and the comprehensive performance of the subsequent composite film, that is, the performance and the structure of the electrochromic film can be controlled by designing the performance and the structure of the transition layer material, for this reason, we propose 5 principles that should be followed in the selection of the transition layer material: (1) the use performance cannot be sacrificed; (2) the environment is protected; (3) color and transparency of the material; (4) matching of energy bands and structures with the substrate and the electrochromic film; (5) environmental tolerance and adaptability. According to the principle, the selection of the material of the transition layer is carried out according to the actual performance requirement. The material of the transition layer can be indium oxide, titanium dioxide, zinc oxide and the like or other materials.

2. Construction of transition layer structures

Firstly, the microstructure design is carried out on the transition layer, a construction scheme is determined, and then the transition layer with a special microstructure is prepared on the surface of the pretreated substrate by adopting a proper technology and a proper method. The transition layer microstructure may be a nanorod array structure, a network structure, a porous array, a multilevel structure, or other structures.

3. Preparation of alternating composite structure electrochromic film

At present, the methods for preparing electrochromic films mainly include magnetron sputtering technology, chemical bath method, electrochemical deposition technology, sol-gel method, hydrothermal method, solvothermal method and the like. The technology and the method can be used for compositely growing the electrochromic layer on the surface of the transition layer with the special microstructure. The following three preparation methods of the electrochromic film with the interpenetration type composite structure are taken as examples.

(1) Preparation of nickel hydroxide/indium oxide electrochromic film with interpenetration type composite structure

Mixing a proper amount of indium trichloride tetrahydrate and urea according to the molar ratio of 1:8-1:12, adding a proper amount of deionized water into the mixture, wherein the mass ratio of the mixture to the deionized water is 1:80-1:110, and stirring for 15-30min to prepare a solution for hydrothermal reaction. Placing the FTO conductive glass substrate in an inner container of a reaction kettle in an inclined way, adding the prepared solution into the inner container of the reaction kettle (about two thirds of the volume of the inner container), reacting at a high temperature for a proper time, and naturally cooling to room temperature. And taking out the glass sheet, washing impurities on the surface with distilled water, then putting the glass sheet into a muffle furnace, keeping the temperature at high temperature for a proper time, cooling to room temperature, and taking out the glass sheet, thus obtaining the indium oxide nanorod array transition layer on the FTO. Dissolving appropriate amount of nickel nitrate hexahydrate in appropriate amount of DMF, wherein the concentration of nickel ions is 0.08-0.12 mol.L^-1And stirring uniformly to obtain a solution for hydrothermal reaction. Placing the FTO with the indium oxide transition layer in an inner container of a reaction kettle in an inclined way, adding the prepared solution, reacting at a high temperature for a proper time, and naturally cooling to room temperature. And taking out the glass sheet, and washing the impurities on the surface with distilled water to obtain the nickel hydroxide/indium oxide electrochromic film with the interpenetrating composite structure.

(2) Preparation of nickel hydroxide/titanium dioxide electrochromic film with interpenetration type composite structure

Mixing 10-20mL of concentrated hydrochloric acid with 10-20mL of deionized water, adding 0.5-2mL of tetrabutyl titanate, and stirring for 5-20min to form a solution for hydrothermal reaction. Placing FTO conductive glass in the inner container of a reaction kettle in an inclined way, adding the prepared solution, reacting at a high temperature and a constant temperature for a proper time, and then carrying out self-reactionThen cooling to room temperature, and preparing the titanium oxide nanorod array transition layer on the FTO. Dissolving appropriate amount of nickel nitrate hexahydrate in appropriate amount of DMF, wherein the concentration of nickel ions is 0.08-0.12 mol.L^-1And stirring uniformly to obtain a solution for hydrothermal reaction. And (3) obliquely placing the FTO with the titanium oxide transition layer grown in the last step into a liner of a reaction kettle, adding the prepared solution, reacting at a high temperature for a proper time, and naturally cooling to room temperature. And taking out the glass sheet, and washing the impurities on the surface with distilled water to obtain the nickel hydroxide/titanium dioxide electrochromic film with the interpenetrating composite structure.

(3) Preparation of nickel oxide/zinc oxide electrochromic film with interpenetration type composite structure

Using platinum electrode as counter electrode, saturated calomel electrode as reference electrode, working electrode connected with FTO glass, electrolyte solution as mixed solution of zinc chloride and potassium chloride, zinc chloride concentration is 1.0 × 10^-3mol·L^-1The concentration of potassium chloride is 0.1 mol.L^-1. The deposition temperature is 50-90 deg.C, constant voltage method is adopted, voltage is-1V, and deposition time is 10min-60 min. And after the reaction is finished, taking out the glass sheet, washing impurities on the surface of the glass sheet by using distilled water, and preparing a zinc oxide nanorod array transition layer on the FTO. A platinum electrode is used as a counter electrode, a saturated calomel electrode is used as a reference electrode, a working electrode is connected with an FTO glass sheet on which a zinc oxide transition layer grows, and the electrolyte is 0.1 mol.L^-1Nickel nitrate hexahydrate solution. The deposition current is 0.15 mA-cm by constant current method²-0.3mA·cm². And (3) depositing for 10-60 min, taking out the glass sheet, washing the glass sheet with distilled water to remove impurities on the surface, drying, putting the glass sheet into a muffle furnace, calcining at high temperature for a certain time, and taking out the glass sheet to obtain the nickel oxide/zinc oxide electrochromic film with the interpenetrating composite structure.

And (3) testing the electrochromic performance of the product: the product is used as a negative electrode and is put into a container with the volume of 0.5 mol.L^-1In the potassium hydroxide electrolyte solution, a platinum sheet (or other material electrode) is used as a positive electrode, and the anode is electrified under the direct-current voltage of 2.5V; then the positive and negative electrodes are switched to be electrified. Before and after the exchange of the positive and negative electrodes, the optical parameters (such as color, light transmittance and the like) of the electrochromic film are changed obviously and can be between two optical statesAnd (6) performing reverse conversion.