Method for preparing polyaniline film with high binding power and high flatness through induction of transition layer and application of polyaniline film

Abstract

The invention discloses a method for preparing a polyaniline film with high binding power and high flatness through induction of a transition layer and application, and the method comprises the following steps: taking conductive glass as a substrate, and carrying out electrochemical deposition in a doped acidic polyaniline solution to obtain a doped substrate transition layer attached to the conductive glass; and carrying out electrochemical deposition in an undoped acidic polyaniline solution by taking the conductive glass attached with the transition layer as a substrate to obtain the polyaniline film material with high binding power and high flatness. According to the invention, by designing the transition layer, the growth kinetics of polyaniline in the electrochemical deposition process is regulated and controlled, and the polyaniline film with high binding power and high flatness is obtained; by adopting the method disclosed by the invention, the stability, the response rate and the multi-spectrum optical regulation and control range of the polyaniline thin film material for electrochromism can be quickly and effectively improved, and the polyaniline thin film material has the characteristic of easiness in wide industrial application, and has a wide prospect in the fields of infrared and visible optical stealth, intelligent windows and other optical regulation and control.

Description

Technical Field

[0001] The invention belongs to the field of electrochromic materials, and relates to a method for preparing a polyaniline film with high adhesion and high flatness by inducing a transition layer and an application thereof, in particular to an application in electrochromism. Background Art

[0002] At present, great progress has been made in the research of materials related to electrochromism, and materials including inorganic electrochromic materials (tungsten trioxide, titanium oxide, vanadium pentoxide, etc.), organic electrochromic materials (polyaniline, polythiophene, polypyrrole, etc.) have been developed. Among them, polyaniline is considered to be an electrochromic material with application prospects due to its simple synthesis, low cost and outstanding electrochemical properties.

[0003] The synthesis of polyaniline is mainly divided into two categories: electrochemical deposition and chemical oxidation polymerization. Electrochemical deposition can prepare polyaniline thin films directly on the electrode surface, which can achieve rapid and large-scale preparation. However, the polyaniline thin films directly obtained on transparent electrodes (ITO glass, FTO glass, etc.) have a porous and loose morphology, and have low adhesion and poor durability when used for electrochromic applications.

[0004] According to the kinetic theory of thin film island growth mode (Volmer-Weber model), the reason why the polyaniline film directly deposited on the conductive glass exhibits a porous and loose morphology is that the contact angle between the polyaniline solution and the conductive glass is too large to effectively nucleate.

[0005] Therefore, the present invention first prepares a dense and flat transition layer on the conductive glass, which has a small contact angle with the polyaniline solution. The synthesis of the transition layer relies on the doping effect of aniline and 3-aminobenzenesulfonic acid or similar substances during polymerization, which can form a five-membered ring or six-membered ring structure to obtain a thin and flat transition layer substrate. At the same time, the conductivity of the transition layer changes with the voltage, which can inhibit the vertical growth of polyaniline during the electrochemical deposition process, and finally obtain a polyaniline film with high adhesion and high flatness. Summary of the invention

[0006] The purpose of the present invention is to provide a method for preparing a polyaniline film with high adhesion and high flatness by using a transition layer induction and its application in view of the problems existing in the prior art. The present invention uses a transition layer induction method to electrochemically deposit a polyaniline film with high adhesion and high flatness on the surface of a conductive glass, thereby achieving morphology control of the polyaniline film and obtaining excellent electrochromic properties.

[0007] The objective of the present invention is achieved through the following technical solutions: The present invention relates to a method for preparing a polyaniline film with high adhesion and high flatness by inducing a transition layer, the method comprising the following steps: S1, placing a conductive glass substrate into a doped acidic polyaniline solution, and performing electrochemical deposition to obtain a conductive glass substrate with a transition layer attached; S2. placing the conductive glass substrate with the transition layer attached thereto into an undoped acidic polyaniline solution, and performing electrochemical deposition on the transition layer to obtain a polyaniline film with high adhesion and high flatness.

[0008] As an embodiment of the present invention, in step S1, the conductive glass substrate has a resistance value between 6 and 20Ω. The conductive glass substrate includes one of ITO and FTO conductive glasses.

[0009] As an embodiment of the present invention, in step S1, before use, the conductive glass substrate is ultrasonically cleaned in sequence with toluene, acetone, anhydrous ethanol, and deionized water to remove impurities on the surface of the conductive glass and obtain a clean conductive glass substrate.

[0010] As an embodiment of the present invention, in step S1, the doped acidic polyaniline solution is an aqueous solution comprising an acid, a doping substance and polyaniline.

[0011] Preferably, the doping substance includes one or more of 3-aminobenzenesulfonic acid, dodecylbenzenesulfonic acid, 1,3,6,8-pyrenetetrasulfonic acid tetrasodium salt, and anthraquinone-1-sulfonate sodium. The concentration of the doping substance is 0.005-0.05M.

[0012] Preferably, the concentration of the polyaniline is 0.005-0.05 M.

[0013] Compared with the porous and loose polyaniline film obtained by direct substrate deposition on the conductive glass, the present invention uses a flat and thin transition layer prepared by a doping substance to regulate the growth kinetics of polyaniline during the electrochemical polymerization process to obtain a polyaniline film with high adhesion and high flatness.

[0014] When the doping substance is copolymerized with aniline to form a polymer, many sulfonic acid groups are introduced into the molecular chain of polyaniline. These sulfonic acid groups can dope their own aniline polymer chains to form a self-doping effect. This self-doping effect caused by the sulfonic acid groups on the side chains can occur both within a molecular chain and between different molecular chains. This self-doping effect, using the interaction between the N element of aniline and the protons on the sulfonic acid groups on the side chains, can form a five-membered ring or six-membered ring structure, which can stabilize the polyaniline polymer skeleton while enhancing the stability of the overall film material. Compared with the pure polyaniline structure of linear polymers, the transition layer obtained by doping belongs to a bulk polymer, and its overall polymer skeleton has a high degree of cross-linking. When polymerized during electrochemical deposition, it tends to grow in a layered form.

[0015] Too much doping material will lead to too much material participating in electrochemical deposition, causing the first transition layer to grow rapidly, with the thickness increasing from the original 100 nm to the micron level, and the surface having hundreds of nanometers or even micron-level fluctuations and agglomerated particles, and the roughness increases. These rough sites on the transition layer will become the cores for the non-uniform nucleation of the second layer of polyaniline film, causing the second layer of polyaniline to grow explosively attached to these cores, affecting the flatness.

[0016] Preferably, the acid comprises one of sulfuric acid and perchloric acid. The concentration of the acid is 0.1-2 M. The concentration is preferably 0.8-1.2 M, more preferably 1 M.

[0017] As an embodiment of the present invention, in step S1, the preparation method of the doped acidic polyaniline solution is: dissolving the doping substance and polyaniline in an acid solution to obtain a mixed solution, and stirring the mixed solution. The stirring is performed at 500 to 700 revolutions per minute for 1 hour to obtain the doped acidic polyaniline solution.

[0018] As an embodiment of the present invention, in step S1, the electrochemical deposition method includes one of cyclic voltammetry, constant voltage method, and pulse voltage method. The parameter settings of the cyclic voltammetry method are a voltage range of 0.5V-2.3V, preferably 0.5~2 V, a scan rate of 10 mV / s, and a deposition cycle of 1 circle; the parameter settings of the constant voltage method are a voltage of 1.5~2.0 V (preferably 1.8 V), and a deposition cycle of 100 seconds; the parameter settings of the pulse voltage method are 0 V deposition for 2 seconds, 1.5~2.0 V (preferably 1.8 V) deposition for 1 second, and 100 cyclic pulses.

[0019] As an embodiment of the present invention, in step S1, after electrochemical deposition, the transition layer attached to the conductive glass substrate is rinsed with deionized water and anhydrous ethanol (3 times), respectively, and then dried naturally at room temperature to obtain a transition layer attached to the conductive glass.

[0020] As an embodiment of the present invention, in step S1, the thickness of the transition layer obtained by electrochemical deposition is 40-150 nm, preferably 50-120 nm.

[0021] As an embodiment of the present invention, in step S2, the undoped acidic polyaniline solution is an aqueous solution comprising acid and polyaniline.

[0022] Preferably, the acid comprises one of sulfuric acid and perchloric acid. The concentration of the acid is 0.1-2 M. The concentration is preferably 0.8-1.2 M, more preferably 1 M.

[0023] Preferably, the concentration of the polyaniline is 0.01-0.1M.

[0024] As an embodiment of the present invention, in step S2, the preparation method of the undoped acidic polyaniline solution is: dissolving polyaniline in an acidic solution to obtain a mixed solution, and stirring the mixed solution. The stirring is performed at 500 to 700 revolutions per minute for 1 hour to obtain the undoped acidic polyaniline solution.

[0025] As an embodiment of the present invention, in step S2, the electrochemical deposition method includes one of cyclic voltammetry, constant voltage method, and pulse voltage method. The parameter settings of the cyclic voltammetry method are a voltage range of -0.2V~1.4V, preferably 0~1.2 V, a scan rate of 10 mV / s, and a deposition cycle of 1 circle; the parameter settings of the constant voltage method are a voltage of 0.8~1.2 V (preferably 1V), and a deposition cycle of 100 seconds; the parameter settings of the pulse voltage method are 0 V deposition for 2 seconds, 0.8~1.2V (preferably 1V) deposition for 1 second, and 100 cyclic pulses.

[0026] As an embodiment of the present invention, in step S2, the polyaniline film obtained after electrochemical deposition is washed with deionized water and anhydrous ethanol (3 times), respectively, and then dried naturally at room temperature to obtain a polyaniline film with high adhesion and high flatness.

[0027] The invention also provides a polyaniline film prepared by the method. The polyaniline film has high adhesion and high flatness.

[0028] The present invention also provides an application of the polyaniline film in smart windows, smart stealth materials, and electrochromic scenes (electrochromic materials). The polyaniline film has high adhesion and high flatness.

[0029] The polyaniline film with high adhesion and high flatness prepared by the method belongs to the protection scope of the present invention.

[0030] The application of the high-adhesive force and high-flatness polyaniline film in seat electrochromic materials also falls within the protection scope of the present invention.

[0031] Compared with the prior art, the present invention has the following beneficial effects: (1) By first depositing a transition layer substrate on the conductive glass, the growth kinetics of polyaniline during the electrochemical polymerization process can be regulated. Compared with the existing method of directly depositing a transition layer substrate on the conductive glass to obtain a porous and loose polyaniline film ( Figure 4 ), the present invention can obtain a polyaniline film with high adhesion and high flatness ( Figure 5 ).

[0032] (2) The highly planarized polyaniline film obtained by the present invention has significantly improved performance compared to the polyaniline film directly deposited on a transparent substrate. Figure 4 , the optical contrast decay after 100 cycles decreased from 50.83% to 20.39%. In terms of response rate, Figure 5 , the original coloring time τc = 5.3 s and fading time τb = 11.7 s are changed to coloring time τc = 5.7 s and fading time τb = 4.2 s, and the fading time is significantly shortened.

[0033] (3) By adopting the method of the present invention, the electrochromic properties of the polyaniline film can be quickly and effectively improved and it has the characteristics of being easy to be widely used in industry, and has broad prospects in smart windows, smart stealth materials and electrochromic scenarios (such as electrochromic batteries, electrochromic anti-counterfeiting, electrochromic displays). BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 is a process flow chart of the present invention; Figure 2 This is a scanning electron microscope image of the transition layer substrate obtained in Example 1; Figure 3 This is a schematic diagram of the doping effect of aniline and 3-aminobenzenesulfonic acid during the synthesis of the transition layer substrate in Example 1; Figure 4 This is a scanning electron microscope image of a porous, loose polyaniline film directly deposited on ITO in Comparative Example 1; Figure 5 This is a scanning electron microscope image of the polyaniline film with high adhesion and high flatness obtained in Example 1; Figure 6 1 is a cyclic stability test curve of two types of polyaniline films in Example 1 and Comparative Example 1; Figure 7 The response speed test curves of two types of polyaniline films in Example 1 and Comparative Example 1 are shown in the figure above. The upper figure is Example 1, and the lower figure is Comparative Example 1. Figure 8 1 is the infrared reflectivity test curve of two types of polyaniline films in Example 1 and Comparative Example 1; Fig. 9 The UV / visible light transmittance curves of two types of polyaniline films in Example 1 and Comparative Example 1; wherein the upper figure is Example 1, and the lower figure is Comparative Example 1; Fig.10 This is a scanning electron microscope image of the polyaniline film prepared in Example 2; Fig.11 This is a scanning electron microscope image of the polyaniline film prepared in Example 3; Fig.12 This is a scanning electron microscope image of the polyaniline film prepared in Example 4; Fig.13 This is a scanning electron microscope image of the polyaniline film prepared in Example 5; Fig.14 This is a scanning electron microscope image of the polyaniline film prepared in Example 6; Fig.15 This is a scanning electron microscope image of the polyaniline film prepared in Example 7; Fig.16 This is a scanning electron microscope image of the polyaniline film prepared in Example 8; Fig.17 This is a scanning electron microscope image of the polyaniline film prepared in Example 9; Fig.18 This is a scanning electron microscope image of the polyaniline film prepared in Comparative Example 2; Fig.19 This is a scanning electron microscope image of the polyaniline film prepared in Comparative Example 3; Fig. 20 This is a thickness (height) flatness test for PANI and D-PANI films, where a is the prepared PANI and D-PANI films, b is the test on the edge of the ITO substrate and PANI film, and c is the test on the edge of the D-PANI film and PANI film. DETAILED DESCRIPTION

[0035] The present invention is described in detail below in conjunction with examples. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several adjustments and improvements can be made without departing from the concept of the present invention. These all belong to the scope of protection of the present invention. All publications mentioned are incorporated by reference in their entirety.

[0036] Example 1 This embodiment relates to a polyaniline film with high adhesion and high flatness for electrochromic and a preparation method thereof. The schematic diagram of the process is shown in FIG. Figure 1 As shown, the specific steps are as follows: (1) The ITO conductive glass was ultrasonically cleaned with toluene, acetone, anhydrous ethanol, and deionized water for 15 minutes in sequence and dried at 60°C for 30 minutes to remove surface impurities and obtain a clean ITO substrate; (2) The ITO substrate obtained in step (1) was immersed in a 1 M sulfuric acid aqueous solution containing 0.05 M 3-aminobenzenesulfonic acid and 0.05 M polyaniline, and a transition layer (100 ± 20 nm) was obtained by performing a cyclic voltammetric scan at a scan rate of 10 mV / s in a potential window of 0.5-2 V relative to a saturated calomel electrode (SCE). Figure 2 As shown in the figure, the principle of the doping effect of aniline and 3-aminobenzenesulfonic acid during the deposition of the transition layer is as follows Figure 3 As shown; (3) The transition layer obtained in step (2) is immersed in a 1 M sulfuric acid aqueous solution containing 0.1 M polyaniline, and a cyclic voltammetry scan is performed once in a potential window of 0-1.2 V relative to a saturated calomel electrode (SCE) at a scan rate of 10 mV / s to obtain a polyaniline film with high adhesion and high flatness, such as Figure 5 shown.

[0037] (4) The obtained polyaniline film was rinsed with deionized water and anhydrous ethanol for three times, respectively, and then dried naturally at room temperature.

[0038] Example 2 (1) The FTO conductive glass was ultrasonically cleaned with toluene, acetone, anhydrous ethanol, and deionized water for 15 minutes in sequence and dried at 60°C for 30 minutes to remove surface impurities and obtain a clean FTO substrate; (2) immersing the FTO substrate obtained in step (1) in a 1 M sulfuric acid aqueous solution containing 0.05 M 3-aminobenzenesulfonic acid and 0.05 M polyaniline, and performing a cyclic voltammetric scan at a scan rate of 10 mV / s in a potential window of 0.5-2 V relative to a saturated calomel electrode (SCE) to obtain a transition layer; (3) The transition layer obtained in step (2) is immersed in a 1 M sulfuric acid aqueous solution containing 0.1 M polyaniline, and a cyclic voltammetry scan is performed once in a potential window of 0-1.2 V relative to a saturated calomel electrode (SCE) at a scan rate of 10 mV / s to obtain a polyaniline film with high adhesion and high flatness, such as Fig.10 .

[0039] (4) The obtained polyaniline film was rinsed with deionized water and anhydrous ethanol for three times, respectively, and then dried naturally at room temperature.

[0040] Example 3 (1) The ITO conductive glass was ultrasonically cleaned with toluene, acetone, anhydrous ethanol, and deionized water for 15 minutes in sequence and dried at 60°C for 30 minutes to remove surface impurities and obtain a clean ITO substrate; (2) immersing the ITO substrate obtained in step (1) in a 1 M sulfuric acid aqueous solution containing 0.05 M dodecylbenzenesulfonic acid and 0.05 M polyaniline, and performing a cyclic voltammetric scan at a scan rate of 10 mV / s in a potential window of 0.5-2 V relative to a saturated calomel electrode (SCE) to obtain a transition layer; (3) The transition layer obtained in step (2) is immersed in a 1 M sulfuric acid aqueous solution containing 0.1 M polyaniline, and a cyclic voltammetry scan is performed once in a potential window of 0-1.2 V relative to a saturated calomel electrode (SCE) at a scan rate of 10 mV / s to obtain a polyaniline film with high adhesion and high flatness, such as Fig.11 .

[0041] (4) The obtained polyaniline film was rinsed with deionized water and anhydrous ethanol for three times, respectively, and then dried naturally at room temperature.

[0042] Example 4 (1) The ITO conductive glass was ultrasonically cleaned with toluene, acetone, anhydrous ethanol, and deionized water for 15 minutes in sequence and dried at 60°C for 30 minutes to remove surface impurities and obtain a clean ITO substrate; (2) immersing the ITO substrate obtained in step (1) in a 1 M sulfuric acid aqueous solution containing 0.05 M 1,3,6,8-pyrenetetrasulfonic acid tetrasodium salt and 0.05 M polyaniline, and performing a cyclic voltammetric scan at a scan rate of 10 mV / s in a potential window of 0.5-2 V relative to a saturated calomel electrode (SCE) to obtain a transition layer; (3) The transition layer obtained in step (2) is immersed in a 1 M sulfuric acid aqueous solution containing 0.1 M polyaniline, and a cyclic voltammetry scan is performed once in a potential window of 0-1.2 V relative to a saturated calomel electrode (SCE) at a scan rate of 10 mV / s to obtain a polyaniline film with high adhesion and high flatness, such as Fig.12 .

[0043] (4) The obtained polyaniline film was rinsed with deionized water and anhydrous ethanol for three times, respectively, and then dried naturally at room temperature.

[0044] Example 5 (1) The ITO conductive glass was ultrasonically cleaned with toluene, acetone, anhydrous ethanol, and deionized water for 15 minutes in sequence and dried at 60°C for 30 minutes to remove surface impurities and obtain a clean ITO substrate; (2) immersing the ITO substrate obtained in step (1) in a 1 M sulfuric acid aqueous solution containing 0.05 M sodium anthraquinone-1-sulfonate and 0.05 M polyaniline, and performing a cyclic voltammetric scan at a scan rate of 10 mV / s in a potential window of 0.5-2 V relative to a saturated calomel electrode (SCE) to obtain a transition layer; (3) The transition layer obtained in step (2) is immersed in a 1 M sulfuric acid aqueous solution containing 0.1 M polyaniline, and a cyclic voltammetry scan is performed once in a potential window of 0-1.2 V relative to a saturated calomel electrode (SCE) at a scan rate of 10 mV / s to obtain a polyaniline film with high adhesion and high flatness, such as Fig.13 .

[0045] (4) The obtained polyaniline film was rinsed with deionized water and anhydrous ethanol for three times, respectively, and then dried naturally at room temperature.

[0046] Example 6 (1) The ITO conductive glass was ultrasonically cleaned with toluene, acetone, anhydrous ethanol, and deionized water for 15 minutes in sequence and dried at 60°C for 30 minutes to remove surface impurities and obtain a clean ITO substrate; (2) immersing the ITO substrate obtained in step (1) in a 1 M sulfuric acid aqueous solution containing 0.005 M 3-aminobenzenesulfonic acid and 0.005 M polyaniline, and performing a cyclic voltammetric scan at a scan rate of 10 mV / s in a potential window of 0.5-2 V relative to a saturated calomel electrode (SCE) to obtain a transition layer (60±10 nm); (3) The transition layer obtained in step (2) is immersed in a 1 M sulfuric acid aqueous solution containing 0.01 M polyaniline, and a cyclic voltammetry scan is performed once in a potential window of 0-1.2 V relative to a saturated calomel electrode (SCE) at a scan rate of 10 mV / s to obtain a polyaniline film with high adhesion and high flatness, such as Fig.14 .

[0047] (4) The obtained polyaniline film was rinsed with deionized water and anhydrous ethanol for three times, respectively, and then dried naturally at room temperature.

[0048] Example 7 (1) The ITO conductive glass was ultrasonically cleaned with toluene, acetone, anhydrous ethanol, and deionized water for 15 minutes in sequence and dried at 60°C for 30 minutes to remove surface impurities and obtain a clean ITO substrate; (2) immersing the ITO substrate obtained in step (1) in a 1 M perchloric acid aqueous solution containing 0.05 M 3-aminobenzenesulfonic acid and 0.05 M polyaniline, and performing a cyclic voltammetric scan at a scan rate of 10 mV / s in a potential window of 0.5-2 V relative to a saturated calomel electrode (SCE) to obtain a transition layer; (3) The transition layer obtained in step (2) is immersed in a 1 M perchloric acid aqueous solution containing 0.1 M polyaniline, and a cyclic voltammetric scan is performed once in a potential window of 0-1.2 V relative to a saturated calomel electrode (SCE) at a scan rate of 10 mV / s to obtain a polyaniline film with high adhesion and high flatness, such as Fig.15 .

[0049] (4) The obtained polyaniline film was rinsed with deionized water and anhydrous ethanol for three times, respectively, and then dried naturally at room temperature.

[0050] Example 8 (1) The ITO conductive glass was ultrasonically cleaned with toluene, acetone, anhydrous ethanol, and deionized water for 15 minutes in sequence and dried at 60°C for 30 minutes to remove surface impurities and obtain a clean ITO substrate; (2) immersing the ITO substrate obtained in step (1) in a 1 M sulfuric acid aqueous solution containing 0.05 M 3-aminobenzenesulfonic acid and 0.05 M polyaniline, and performing a constant potential scan for 100 s at a potential of 1.8 V relative to a saturated calomel electrode (SCE) to obtain a transition layer; (3) The transition layer obtained in step (2) is immersed in a 1 M sulfuric acid aqueous solution containing 0.1 M polyaniline, and a high adhesion and high flatness polyaniline film is obtained by performing a constant potential scan for 100 s at a potential of 1 V relative to a saturated calomel electrode (SCE), such as Fig.16 .

[0051] (4) The obtained polyaniline film was rinsed with deionized water and anhydrous ethanol for three times, respectively, and then dried naturally at room temperature.

[0052] Example 9 (1) The ITO conductive glass was ultrasonically cleaned with toluene, acetone, anhydrous ethanol, and deionized water for 15 minutes in sequence and dried at 60°C for 30 minutes to remove surface impurities and obtain a clean ITO substrate; (2) immersing the ITO substrate obtained in step (1) in a 1 M sulfuric acid aqueous solution containing 0.05 M 3-aminobenzenesulfonic acid and 0.05 M polyaniline, and scanning 100 times at a voltage of 0 V for 2 s and at a voltage of 1.8 V for 1 s relative to a saturated calomel electrode (SCE) to obtain a transition layer; (3) The transition layer obtained in step (2) is immersed in a 1 M sulfuric acid aqueous solution containing 0.1 M polyaniline, and the transition layer is scanned 100 times by scanning at a voltage of 0 V for 2 s and 1 V for 1 s relative to a saturated calomel electrode (SCE), thereby obtaining a polyaniline film with high adhesion and high flatness, such as Fig.17 .

[0053] (4) The obtained polyaniline film was rinsed with deionized water and anhydrous ethanol for three times, respectively, and then dried naturally at room temperature.

[0054] Comparative Example 1 The steps are basically the same as those in Example 1, except that: the transition layer prepared in step (2) is omitted, and the polyaniline film is directly prepared, such as Figure 4 shown.

[0055] The performance of the polyaniline films obtained in Example 1 and Comparative Example 1 was tested.

[0056] Cyclic stability test: When testing the cyclic stability of the film, the same method as the response rate test is used to obtain the in-situ transmitted light spectrum in the 630 nm band and record the highest and lowest transmittances in each voltage cycle.

[0057] Response speed test: When measuring the response rate of the film, we use a UV / visible / near-infrared spectrophotometer (Lambda 950), fix the test wavelength on the spectrophotometer at 630 nm, and use an electrochemical workstation to alternately apply -0.2 V and 1.0 V voltages to the film. Each voltage is applied for 20 seconds, and the in-situ transmission light spectrum of the 630 nm band can be obtained. Generally speaking, we define the time required for the film transmittance to change by 90% as the response time of the film. Based on the spectrum of the 630 nm band, we can calculate the response time required for the film to color and fade.

[0058] Infrared reflectivity test: The infrared reflectivity curve of the prepared polyaniline sample can be directly read using a Nicolet 6700 infrared spectrometer.

[0059] UV / visible light transmittance: The spectrum test of UV / visible light band is measured in situ by UV-visible light photometer (EV300). When measuring, we use platinum wire electrode as counter electrode, micro Ag / AgCl electrode as reference electrode, and then deposit the film on 80*9 mm ITO as working electrode, and the electrolyte is 1 M H 2 SO 4 Aqueous solution, electrochemical workstation CHI760E. The wavelength range of 300-800 nm was selected for testing, and the test voltages were -0.2 V, 0 V, 0.2 V, 0.4 V, 0.6 V, 0.8 V, and 1.0 V. The difference between the film coloring state and the faded state was extracted from the corresponding spectrum, which is the optical contrast of the film.

[0060] For the sake of explanation, Figure 4 The fiber porous film is a PANI film. Figure 5 The high flatness film is D-PANI film; The cyclic stability test curves of the two types of polyaniline films in Example 1 and Comparative Example 1 are as follows: Figure 6 As shown: After 100 electrochromic cycles, the transmittance of the PANI film at 630nm in the colored state increased from about 8% to about 20%, and the transmittance at 630nm in the faded state decreased from about 70% to about 50%, and the optical contrast decreased from 61.26% to 30.12%, a decline of 50.83%; the transmittance of the D-PANI film at 630nm in the colored state increased from about 20% to about 28%, and the transmittance at 630nm in the faded state decreased from about 82% to about 77%, and the optical contrast decreased from 62.05% to 49.40%, only a decline of 20.39%. Response speed test curve is as follows: Figure 7 As shown (the upper figure is comparative example 1, the lower figure is example 1): the coloring time τ of the PANI film c is 5.3s, and the fading time is τ b =11.7s. The figure below is the spectrum of D-PANI film in the 630nm band. According to the spectrum curve, the coloring time τ of D-PANI film can be read out. c is 5.7s, and the fading time is τ b =4.2s. The coloring time of the two films is relatively close, but the fading time of the D-PANI film is significantly shorter.

[0061] Infrared reflectivity test curve Figure 8 As shown: It can be found that the infrared reflectivity of both PANI film and D-PANI film changes with the change of voltage, and the infrared reflectivity shows a downward trend with the increase of the applied voltage. Here, we call -0.2 V the low emission state, 0.4 V the medium emission state, and 1.0 V the high reflection state. It can be calculated that the average infrared emissivity of PANI film in the low, medium and high states is 0.547, 0.701, and 0.829 respectively; the average infrared emissivity of D-PANI film in the low, medium and high states is 0.351, 0.845, and 0.939 respectively. Compared with PANI film, D-PANI film decreases by 0.196 in the low emissivity state and increases by 0.110 in the high emissivity state in the infrared band, and the emissivity control range is expanded by nearly 109%, which can better adapt to the needs of changes in environmental infrared signals and has a more superior infrared stealth capability.

[0062] UV / visible light transmittance curve is as follows Fig. 9 As shown: the maximum optical contrast of PANI film is 61.3%, which appears in the 630 nm band; the maximum optical contrast of D-PANI film is 61.5%, which appears in the 660 nm band.

[0063] Comparative Example 2 The steps are basically the same as those in Example 1, except that the acid solution in step (2) does not contain 3-aminobenzenesulfonic acid.

[0064] Provide SEM morphology photos such as Fig.18 As shown, since the first film is the loose film in comparative example 1, the adhesion is weak, so it has fallen off when the second layer is deposited, and the subsequent performance test cannot be performed.

[0065] Comparative Example 3 The steps are basically the same as those in Example 1, except that the concentration of 3-aminobenzenesulfonic acid in the acid solution in step (2) is 1 M.

[0066] like Fig.19 As shown, many clustered particles appeared, and the flatness was significantly reduced compared with Example 1.

[0067] Comparative Example 4 The steps are basically the same as those in Example 1, except that the acid solution in step (2) does not contain sulfuric acid, but the concentration of 3-aminobenzenesulfonic acid is 1 M.

[0068] The synthesis of polyaniline film is directly affected by the pH value of the environment. Due to the weakening of acidity, the first layer does not grow sufficiently during preparation, resulting in a decrease in the flatness of both layers of the film.

[0069] Roughness and flatness test: The surface roughness of Example 1 and Comparative Example 1 was tested. Figure 4 , Figure 5 It can be seen that Comparative Example 1 is fibrous, and Comparative Example 2 is a flat film, with an intuitive difference in flatness.

[0070] The thickness (height) of PANI and D-PANI films was further tested using a material-type upright laser confocal microscope (VK-X3000). The test sample must undergo two electrochemical depositions. In the first, half of the ITO substrate was immersed in a 3-aminobenzenesulfonic acid-doped polyaniline electrochemical deposition solution for deposition, and a sample with half blank and half transition layer was obtained. In the second time, the sample was rotated 90° and clamped on a glassy carbon electrode clamp, and half of the sample was immersed in a pure polyaniline electrochemical deposition solution for deposition, and samples with 1 / 4 blank, 1 / 4 transition layer, 1 / 4 PANI film, and 1 / 4 D-PANI film were obtained, such as Fig. 20 As shown in a. The boundary lines between the blank and the PANI film, and between the PANI film and the D-PANI film were photographed respectively.

[0071] like Fig. 20 As shown, the blue part in the upper part of (b) is the ITO substrate, and the green part in the middle is the edge of the PANI film. Due to the edge effect, the thickness of this edge film is thinner, and the red part is the PANI film. The blue part in the upper part of (c) is the D-PANI film, the green part in the middle is the edge of the PANI film, and the red part is the PANI film. It can be seen that there are many green spots in the red part of the PANI film, and the height difference between the two is about 3 microns. These particles are actually the porous areas that appear in the microscopic morphology of the PANI film; compared with the red area, the height fluctuation of the blue area in (c) is significantly smaller, about only a few hundred nanometers. In other words, the flatness of the D-PANI film is higher.

[0072] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A method for preparing a polyaniline film with high adhesion and high flatness by inducing a transition layer, characterized in that: The method comprises the following steps: S1. placing a conductive glass substrate in a doped acidic polyaniline solution for electrochemical deposition to obtain a conductive glass substrate with an attached transition layer; the doping substance in the doped acidic polyaniline solution includes one or more of 3-aminobenzenesulfonic acid, dodecylbenzenesulfonic acid, 1,3,6,8-pyrenetetrasulfonic acid tetrasodium salt, and anthraquinone-1-sulfonate sodium; S2. placing the conductive glass substrate with the transition layer attached thereto into an undoped acidic polyaniline solution, and performing electrochemical deposition on the transition layer to obtain a polyaniline film with high adhesion and high flatness.

2. The method for preparing a polyaniline film with high adhesion and high flatness by using a transition layer induction according to claim 1, characterized in that: In step S1, the resistance value of the conductive glass substrate is between 6 and 20 Ω; And / or, the conductive glass substrate includes one of ITO and FTO type conductive glasses.

3. The method for preparing a polyaniline film with high adhesion and high flatness by using a transition layer induction according to claim 1, characterized in that: In step S1, the doped acidic polyaniline solution is an aqueous solution comprising acid, doping substance and polyaniline.

4. The method for preparing a polyaniline film with high adhesion and high flatness by using a transition layer induction according to claim 3, characterized in that: The acid includes one of sulfuric acid and perchloric acid; and / or, the acid concentration is 0.1 to 2 M; and / or, the concentration of the doping substance is 0.005~0.05 M; And / or, the concentration of polyaniline is 0.005~0.05M.

5. The method for preparing a polyaniline film with high adhesion and high flatness by using a transition layer induction according to claim 1, characterized in that: In step S2, the undoped acidic polyaniline solution is an aqueous solution comprising acid and polyaniline.

6. The method for preparing a polyaniline film with high adhesion and high flatness by using a transition layer induction according to claim 5, characterized in that: The acid concentration is 0.1~2 M; And / or, the concentration of polyaniline is 0.01~0.1M.

7. The method for preparing a polyaniline film with high adhesion and high flatness by using a transition layer induction according to claim 1, characterized in that: In step S1, the electrochemical deposition method includes one of cyclic voltammetry, constant voltage method, and pulse voltage method; And / or, in step S2, the electrochemical deposition method includes one of cyclic voltammetry, constant voltage method, and pulse voltage method.

8. The method for preparing a polyaniline film with high adhesion and high flatness by using a transition layer induction according to claim 7, characterized in that: In step S1, the parameter settings of the cyclic voltammetry method are a voltage range of 0.5V-2.3V, a scan rate of 10mV / s, and a deposition cycle of 1 cycle; the parameter settings of the constant voltage method are a voltage of 1.5-2.0V, a deposition cycle of 100 seconds; the parameter settings of the pulse voltage method are 0V deposition for 2 seconds, 1.5-2.0V deposition for 1 second, and 100 cyclic pulses; And / or, in step S2, the parameter settings of the cyclic voltammetry method are a voltage range of -0.2V~1.4V, a scan rate of 10mV / s, and a deposition cycle of 1 circle; the parameter settings of the constant voltage method are a voltage of 0.8~1.2V, a deposition cycle of 100 seconds; and the parameter settings of the pulse voltage method are 0 V deposition for 2 seconds, 0.8~1.2 V deposition for 1 second, and 100 cyclic pulses.

9. A polyaniline film prepared by the method according to any one of claims 1 to 8.

10. Application of the polyaniline film as claimed in claim 9 in smart windows, smart stealth materials, and electrochromic scenes.

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