PEDOT conductive polymer based on ClO4 <-> and PF6 <-> doping system

Abstract

The invention discloses a PEDOT conductive polymer based on a ClO4 <-> and PF6 <-> doping system, and relates to an organic photoelectric material. According to the invention, based on different doping systems (ClO4 <-> and PF6 <->), the electrochemical performance, the electrochromic behavior, the thermal stability and the change of the surface appearance of poly (3, 4-ethylenedioxythiophene) (PEDOT) are researched. The electrochromic performance of PEDOT is improved through doping, and the method has important guiding significance on electrochromic application of the polymer. The invention discloses a preparation method for doping ClO4 <-> and PF into a polymer PEDOT (poly (3, 4-ethylenedioxythiophene)), the series of conductive polymers are doped by using different doping agents, so that the optical contrast and coloring efficiency of electrochromism are improved, and the conductive polymers are novel electrochromism functional layer materials.

Description

Technical Field

[0001] This invention relates to the field of organic optoelectronic materials and devices, particularly those based on ClO4. - and PF6 - Application of PEDOT conductive polymers with doped systems in the field of electrochromism. Background Technology

[0002] Conductive polymers are polymer materials with a conjugated structural system (primarily referring to conjugated π bonds) after being doped by chemical or electrochemical methods. Among the developed conductive polymers, polythiophene (PTh) has attracted much attention due to its stable molecular structure and wide range of derivatives, making it highly attractive in organic electronics. However, its relatively low conductivity (due to low conjugation) and poor processability (lack of side chains) limit its practical applications. To address these issues, scientists at Bayer AG in Germany developed poly(3,4-ethylenedioxythiophene) (PEDOT), using 3,4-ethylenedioxythiophene (EDOT) as the monomer. PEDOT polymers possess a rigid backbone and high conjugation. The steric barrier of the ethylenedioxy group effectively protects the polymer from external oxidants and prevents defects during polymerization (such as β-defects, branching, crosslinking, and co-coupling). This enhances the regularity of the polymer, giving the material unprecedented stability in air and water.

[0003] PEDOT can be obtained through chemical oxidative polymerization, electrochemical polymerization, and gas-phase polymerization. When the PEDOT backbone is oxidized, polarons / bipolarons are generated, which require anion (para-ion) doping to stabilize the positive charge. The doping level directly determines the conductivity and light absorption characteristics. Traditional dopants include ClO4⁻, PF6⁻, Tos⁻, etc., whose size, charge density, and solvation ability affect the interchain distance and carrier mobility. In addition to its strong conductivity, good film-forming properties, and high stability, PEDOT also has a low band gap and good transparency. Furthermore, it has strong adhesion, variable film color, and good cycling and durability, making it widely used in the field of electronic color change. Electronic color change is defined as a reversible and visible change in the transmittance and / or reflectance of a material caused by an applied voltage. In the doped state, PEDOT films have high transmittance and are nearly transparent sky blue; after dedoping, they have high absorptivity and are deep blue. PEDOT can be used as an active material and transparent electrode material in the field of electrochromic applications, and PEDOT and its derivatives are among the few cathode coloring materials. These advantages are reflected in the number of published papers and patents.

[0004] However, the impact of doping on the electrochromic properties of PEDOT needs further investigation, such as the effects of different concentrations and types of anions on color coordinates, optical contrast, response time, and coloring efficiency. In this work, we doped ClO4⁻ and PF6⁻ into the corresponding polymer PEDOT via electrochemical polymerization of EDOT monomers and investigated their electrochemical and electrochromic properties. We hope that our research can improve the electrochromic properties of PEDOT through controlled doping, thereby inspiring more innovative research on conductive polymers as electrochromic materials. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by using ClO4 as a basis. - and PF6 - This study investigates the preparation methods of PEDOT conductive polymers with doped systems and explores their optical properties. This series of conductive polymers, through doping with different dopants, enhances the optical contrast and coloring efficiency of electrochromic systems, representing a novel class of electrochromic functional layer materials.

[0006] This invention is achieved through the following technical solution: A first aspect of the present invention provides a ClO4-based - and PF6 - The PEDOT conductive polymer of the doped system is characterized by having the following structure:

[0007] A second aspect of the present invention provides the above-mentioned ClO4-based - and PF6 - A method for preparing a PEDOT conductive polymer doped with a specific dopant system includes the following steps: Conductive polymers were obtained by electrochemical copolymerization of 3,4-ethylenedioxythiophene monomers in polycarbonate-lithium perchlorate, water-lithium perchlorate, tetrahydrofuran-tetrabutylfluorophosphate and isopropanol-tetrabutylfluorophosphate electrolyte solutions.

[0008] Preferably, in the above steps, the molar ratio of 3,4-ethylenedioxythiophene monomer and the electrolyte solutions of polycarbonate-lithium perchlorate, water-lithium perchlorate, tetrahydrofuran-tetrabutylfluorophosphate and isopropanol-tetrabutylfluorophosphate is 1:1.

[0009] A third aspect of the present invention provides the application of the above-described conductive polymer in the field of electrochromism. Attached Figure Description

[0010] Figure 1 For a scan rate of 100 mV·s -1CV plots of 0.01 M EDOT monomer in PC-LiClO4 (0.01 M, A) and H2O-LiClO4 (0.01 M, B). Figure 2 For a scan rate of 100 mV·s -1 CV plots of 0.01 M EDOT monomer in THF-TBAPF6 (0.01 M, C) and IPA-TBAPF6 (0.01 M, D). Figure 3 The spectroelectrochemical spectra of (A) PEDOT-A, (B) PEDOT-B in 0.1 M MeCN-LiClO4 solution and (C) PEDOT-C and (D) PEDOT-D in 0.1 M MeCN-TBAPF6 solution at different voltages are shown.

[0011] Figure 4 The kinetic curves are for (A) PEDOT-A, (B) PEDOT-B, (C) PEDOT-C, and (D) PEDOT-D. Detailed Implementation

[0012] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0013] To enable those skilled in the art to better understand the technical solutions of this application, the technical solutions of this application will be described in detail below with reference to specific embodiments. Unless otherwise specified, experimental conditions not detailed in the embodiments are generally based on conventional conditions or conditions recommended by the reagent company; reagents, consumables, etc., used in the following embodiments can be obtained commercially unless otherwise specified. Example

[0014] Based on ClO4 - Preparation of PEDOT conductive polymers with doped systems The specific reaction steps and reaction conditions are as follows: Electrochemical polymerization apparatus: Indium tin oxide (ITO) was used as the working electrode, a platinum sheet (1 cm × 1 cm) as the counter electrode, and an Ag / AgCl electrode as the reference electrode. 3,4-ethylenedioxythiophene monomer (0.01 M) and supporting electrolyte LiClO4 (0.1 M) were mixed under ambient conditions at 100 mV s⁻¹. -1Electropolymerization of EDOT (0.01 M solution) was performed in different systems at different scan rates, with 10 cycles. PEDOT films were prepared by cyclic voltammetry (CV) in PC-LiClO4 (0.01 M, i.e., PEDOT-A) and H2O-LiClO4 (0.01 M, i.e., PEDOT-B). Figure 1 The film formation voltages were 1.1 V and 0.8 V, respectively, and the film formation time was 50 s for both. During the polymerization process, a deep blue PEDOT polymer film was formed on the surface of the ITO electrode. Example

[0015] Based on PF6 - Preparation of PEDOT conductive polymers with doped systems The specific reaction steps and reaction conditions are as follows: Electrochemical polymerization apparatus: Indium tin oxide (ITO) was used as the working electrode, a platinum sheet (1cm × 1cm) as the counter electrode, and an Ag / AgCl electrode as the reference electrode. 3,4-ethylenedioxythiophene monomer (0.01 M) and supporting electrolyte TBAPF6 (0.1 M) were mixed under ambient conditions at 100 mV s⁻¹. -1 Electropolymerization of EDOT (0.01 M solution) was performed in different systems at different scan rates, with 10 cycles. PEDOT films were prepared using cyclic voltammetry (CV) in THF-TBAFP6 (0.01 M, i.e., PEDOT-C) and IPA-TBAFP6 (0.01 M, i.e., PEDOT-D). Figure 2 The film formation voltages were 1 V and 1.2 V, and the film formation time was 50 s. During the polymerization process, a deep blue PEDOT polymer film was formed on the surface of the ITO electrode. Example

[0016] Taking the polymer materials obtained in Examples 1 and 2 as examples, their application in the field of electrochromic materials. The following examples will illustrate the polymer provided by the present invention and its application process in the field of electrochromic technology, but the present invention is not limited to the examples given.

[0017] (1) Spectroelectrochemistry The ITO conductive glass polymer films obtained in Examples 1 and 2 were placed in a three-electrode electrolytic cell containing an acetonitrile solution of tetrabutylammonium hexafluoride. The working electrode was the ITO conductive glass with the polymer film attached, the counter electrode was a platinum sheet, and the reference electrode was an Ag / AgCl electrode. Using a potentiostatic method, the voltage applied to the working electrode was adjusted via an electrochemical workstation, and the changes in the polymer's absorption spectrum at different voltages were recorded using a UV-Vis spectrometer, thus obtaining the polymer's spectroelectrochemical spectrum (e.g., ...). Figure 3 ).

[0018] (2) Dynamics The characterization was performed using a spectroscopy and electrochemical workstation (XP-SEC-BAC), with an Ag / AgCl electrode as the reference electrode, an indium tin oxide (ITO) coated glass slide as the working electrode, and a platinum wire as the counter electrode in a transparent cuvette. All characterizations were conducted in an acetonitrile solution (0.1 M) of tetrabutylammonium hexafluoride. Transmittance changes were measured using square wave potential, revealing differences in optical contrast among the different polymer films (e.g., ...). Figure 4 ).

[0019] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. Based on ClO4 - and PF6 - The PEDOT conductive polymer of the doped system is characterized by, It has the following structure: ， Where n is a natural number from 1 to 10000.

2. The method for preparing the conductive polymer according to claim 1, characterized in that, Conductive polymers were obtained by electrochemical copolymerization of 3,4-ethylenedioxythiophene monomers in polycarbonate-lithium perchlorate, water-lithium perchlorate, tetrahydrofuran-tetrabutylfluorophosphate and isopropanol-tetrabutylfluorophosphate electrolyte solutions.

3. The ClO4-based [material] according to any one of claims 1 - and PF6 - PEDOT conductive polymers with doped systems have been applied in the field of electrochromism.

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