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CN-122018207-A - Ferroelectric-polyacid coupled long memory composite electrochromic film and preparation method and application thereof

CN122018207ACN 122018207 ACN122018207 ACN 122018207ACN-122018207-A

Abstract

The invention provides a ferroelectric-polyacid coupled long memory composite electrochromic film, a preparation method and application thereof, and belongs to the technical field of electrochromic materials and devices. The film is composed of FTO conductive glass, a TiO 2 porous skeleton layer, a P 2 W 17 V polyacid layer deposited in the skeleton and a P (VDF-TrFE) ferroelectric functional layer, and is deeply coupled with a polyacid oxidation-reduction process through a built-in electric field generated by polarization of the ferroelectric layer, so that charges are effectively locked, ion diffusion is inhibited, and the limitation of traditional physical lamination is broken. The optical memory time of the prepared film is improved from 489.8s to 2357.2s, the bistable property is obviously enhanced, and the process flow is simple.

Inventors

  • LIN JUNLIANG
  • GUAN TONG
  • Dang Xinlu
  • WANG SHIMING

Assignees

  • 辽宁大学

Dates

Publication Date
20260512
Application Date
20260415

Claims (10)

  1. 1. A ferroelectric-polyacid coupled long memory composite electrochromic film is characterized by being of an integrated structure and sequentially comprising an FTO conductive glass substrate, a TiO 2 porous skeleton layer, a P 2 W 17 V polyacid color-changing layer deposited in the skeleton and a P (VDF-TrFE) ferroelectric functional layer forming a polarization coupling interface with the same.
  2. 2. A method for preparing the ferroelectric-polyacid coupled long memory composite electrochromic film according to claim 1, comprising the following steps: 1) Cleaning and drying the FTO conductive glass substrate; 2) Coating TiO 2 slurry on the surface of the FTO conductive glass, and forming a TiO 2 porous skeleton layer through high-temperature sintering; 3) Preparing an acidic aqueous solution containing P 2 W 17 V, and depositing P 2 W 17 V in a TiO 2 porous framework by adopting a cyclic voltammetry to form a P 2 W 17 V polyacid color-changing layer; 4) Dissolving P (VDF-TrFE) powder in an N, N-dimethylformamide solvent to prepare a solution, and spin-coating the solution on the surface of the FTO conductive glass treated in the step 3); 5) And carrying out graded heat treatment after spin coating to crystallize P (VDF-TrFE), and constructing a ferroelectric coupling functional layer tightly combined with the polyacid layer to obtain the ferroelectric-polyacid coupled long memory composite electrochromic film.
  3. 3. The preparation method of the ferroelectric-polyacid coupled long memory composite electrochromic film according to claim 2 is characterized in that in the step 1), the specific cleaning process comprises the steps of immersing FTO conductive glass in acetone, deionized water and ethanol in sequence, respectively carrying out ultrasonic cleaning for 30 minutes, and drying with nitrogen after cleaning.
  4. 4. The preparation method of the ferroelectric-polyacid coupled long memory composite electrochromic film is characterized in that in the step 2), the coated TiO 2 slurry is subjected to screen printing, the number of printing layers is two, and the specific procedure of high-temperature sintering is that the film is firstly dried for 3 minutes at 80 ℃ and then heated to 450 ℃ for sintering for 30 minutes.
  5. 5. The method for preparing the ferroelectric-polyacid coupled long memory composite electrochromic film according to claim 2, wherein in the step 3), the preparation method of the acidic aqueous solution containing P 2 W 17 V is that the acidic aqueous solution is mixed according to the proportion of 0.1g P 2 W 17 V corresponding to 25ml deionized water, the solution is magnetically stirred after being dispersed for 1 minute by ultrasonic, and finally concentrated hydrochloric acid is added dropwise until the solution becomes yellow, clear and transparent.
  6. 6. The method for preparing a ferroelectric-polyacid coupled long memory composite electrochromic film according to claim 2, wherein in the step 3), the parameters of the cyclic voltammetry are set to be in a voltage range of 0.3V to-1.0V, a scanning speed of 100mv/s and a scanning turn number of 30 turns.
  7. 7. The method for preparing a ferroelectric-polyacid coupled long memory composite electrochromic film according to claim 2, wherein in step 4), the preparation condition of the P (VDF-TrFE) solution is that the solution is magnetically stirred for 2 hours at 80 DEG C Until the solution is completely dissolved, wherein the mass concentration of the solution is 0.1 to 6 weight percent.
  8. 8. The method for preparing the ferroelectric-polyacid coupled long memory composite electrochromic film according to claim 7, wherein in the step 4), the spin-coating speed and time are set according to the solution concentration, wherein when the solution concentration is 0.1-2 wt%, the spin-coating speed is 2000r/min, the spin-coating time is 30s, and when the solution concentration is 4-6 wt%, the spin-coating speed is 3000r/min, and the spin-coating time is 30s.
  9. 9. The method for preparing the ferroelectric-polyacid coupled long memory composite electrochromic film according to claim 2, wherein in the step 5), the step of graded heat treatment specifically comprises the steps of pre-drying for 5 minutes on a hot plate at 80 ℃ after spin coating, and then annealing for 2 hours in an oven at 140 ℃ with the heating and cooling mode along with the furnace.
  10. 10. The use of the ferroelectric-polyacid coupled long memory composite electrochromic film of claim 1 in the preparation of long optical memory time electrochromic devices.

Description

Ferroelectric-polyacid coupled long memory composite electrochromic film and preparation method and application thereof Technical Field The invention belongs to the technical field of electrochromic materials and devices, and particularly relates to a ferroelectric-polyacid coupled long-memory composite electrochromic film, and a preparation method and application thereof. Background Polyacids (e.g., P 2W17 V) as an inorganic cluster material have excellent redox activity and various color changes. However, the conventional polyacid electrochromic materials generally have the problem of insufficient optical memory capacity, namely, the film can fade rapidly after the applied voltage is removed. In the prior art, the open-circuit memory time of the pure polyacid film in the liquid electrolyte is generally short, the transmittance of the pure polyacid film is often changed remarkably (for example, the transmittance is attenuated by more than 10%) within tens of seconds to 120 seconds after power failure, and the requirement of low-energy consumption display is difficult to meet. The existing improvement methods focus on chemical crosslinking or physical adsorption, and although stability is improved to some extent, improvement in the optical memory time (i.e., the time to maintain a colored state after power failure) is limited. Ferroelectric materials have unique remnant polarization characteristics, and the built-in electric field existing inside the ferroelectric materials is expected to continuously act on the color-changing materials after power failure, so that the color state is locked. Therefore, the single structure limitation of the traditional polyacid film is broken, a ferroelectric-polyacid integrated coupled composite film is developed, the redox state of the polyacid is regulated and controlled by utilizing a ferroelectric polarization field between heterogeneous interfaces, and the composite film has important significance for realizing a long-memory and high-stability electrochromic device. Disclosure of Invention Aiming at the problems, the invention provides a ferroelectric-polyacid coupled long memory composite electrochromic film and a preparation method thereof. By constructing a ferroelectric-polyacid integrated composite structure, the ferroelectric polymer P (VDF-TrFE) and the polyacid P 2W17 V are tightly combined under the nano scale. The strong built-in electric field generated by ferroelectric polarization characteristics at the interface is utilized to deeply couple oxidation and reduction of polyacid molecules, so that the optical memory time of the electrochromic film is remarkably prolonged, meanwhile, the integrated compact configuration effectively prevents loss of ions, and the cycling stability of the film is improved. In order to achieve the above purpose, the invention adopts the following technical scheme: a preparation method of a ferroelectric-polyacid coupled long memory composite electrochromic film comprises the following steps: 1) And cleaning and drying the FTO conductive glass substrate. 2) And (3) coating TiO 2 slurry on the surface of the FTO conductive glass by screen printing, and performing high-temperature sintering to form the TiO 2 porous framework. 3) An acidic aqueous solution containing P 2W17 V was prepared and P 2W17 V was deposited in the porous TiO 2 skeleton by cyclic voltammetry. 4) And (3) dissolving P (VDF-TrFE) powder in an N, N-Dimethylformamide (DMF) solvent to prepare a solution, and spin-coating the solution on the surface of the FTO conductive glass treated in the step (3). 5) After spin coating, a graded heat treatment is performed to crystallize P (VDF-TrFE) and form a protective film having ferroelectric properties, and a weak bond is formed with P 2W17V-TiO2. Further, in the step 1), the specific cleaning process comprises the steps of immersing the FTO conductive glass in acetone, deionized water and ethanol in sequence, respectively carrying out ultrasonic cleaning for 30 minutes, and drying by nitrogen after cleaning. Further, in the step 2), the screen printing process is adopted for coating, the number of printing layers is two, and the specific procedure of high-temperature sintering is that the high-temperature sintering is carried out for 3 minutes under the condition of 80 ℃ firstly, and then the temperature is raised to 450 ℃ for sintering for 30 minutes. In step 3), the preparation method of the acidic aqueous solution containing P 2W17 V comprises the steps of mixing according to the proportion of 0.1g P 2W17 V to 25ml of deionized water, performing ultrasonic dispersion for 1 minute, magnetically stirring, and finally dropwise adding concentrated hydrochloric acid until the solution becomes yellow, clear and transparent. The parameters of the cyclic voltammetry are set to be in a voltage range of 0.3V to-1.0V, a scanning speed of 100mv/s and a scanning turn number of 30 turns. Further, in the step 4), the preparation con