Method for electrically synthesizing thienyl conductive polymer film in aqueous solution and application of thienyl conductive polymer film

Abstract

The invention provides a method for electrosynthesizing a thienyl conductive polymer film in an aqueous solution and application of the film. The method comprises the steps of electrochemically synthesizing the conductive polymer film in the aqueous solution and metalizing the film. According to the traditional preparation method of the thienyl conductive polymer film, the solubility of a polymer monomer is poor, so that the monomer is generally required to be modified or dissolved in a special organic solvent. The use of an organic solvent not only causes pollution to the environment, but also limits the universality of polymer film preparation to a certain extent, and influences the large-scale application of the polymer film. According to the method for electrically synthesizing the thienyl conductive polymer film in the aqueous solution, the aqueous electrolyte solution adopted in the method is low in price and almost free of pollution to the environment, and the high-quality and high-stability thienyl conductive polymer film can be rapidly prepared through the method. The film can be further subjected to metallization modification and can be applied to the field of various electronic products, especially flexible and wearable electronic information products.

Description

Technical Field

[0001] The invention belongs to the technical field of conductive polymer metallization, and particularly relates to a method for electrosynthesizing a conductive polymer film of a thiophene-based system in an aqueous solution and a metallization application thereof.

[0002] Specifically, the present invention relates to synthesizing a thiophene-based conductive polymer film by an electrochemical method, and metallizing the film by an electrochemical technique. The technology not only provides a method for electrosynthesizing a stable, low-cost thiophene-based conductive polymer film in an aqueous solution, but also performs metal deposition on the thiophene-based conductive polymer film, thereby optimizing and improving the polymer performance and broadening the application field of the polymer, especially in flexible, wearable, portable and other electronic information products. Technical Background

[0003] With the rapid development of materials science and electronic technology, the method of giving excellent conductivity and mechanical stability to conductive polymers by depositing a metal layer on their surface has been widely used in flexible electronic devices, aerospace and advanced circuits. Thiophene-based conductive polymers have excellent conductivity, chemical stability and mechanical flexibility, and are one of the most promising candidate materials for direct electrodeposition of metals. Traditional methods for preparing thiophene-based conductive polymer films usually rely on organic solvents. For example, the invention patent CN1962961A discloses a polythiophene film prepared from an acetonitrile solution containing monomers and supporting electrolytes, which not only pollutes the environment, but also limits its commercial application under special circumstances. In addition, the thiophene monomer is modified by using ion doping to increase the solubility of the monomer in the aqueous solution, thereby forming a polymer film. For example, the invention patent CN113737241A discloses a thiophene derivative doped with sodium polystyrene sulfonate (PSS), and the modified derivative is electrosynthesized in an aqueous solution of sodium dodecylbenzene sulfonate (SDBS) to prepare a water-soluble polythiophene film. The above method requires the use of organic solutions that are polluting to the environment and harmful to human health, or requires the use of monomers to be modified to enhance their solubility, thereby realizing the preparation of polymer films. In addition, the above method uses high-cost raw materials, which is not conducive to achieving large-scale industrial production with economic benefits. The method proposed in this patent is a method for preparing high-quality, high-stability, low-cost thiophene-based conductive polymer films, and the formed polymer can be used in flexible, wearable, and portable electronic information products after metallization, expanding the application field of polymers. Summary of the invention

[0004] The purpose of the present invention is to provide a method for electrosynthesizing a thiophene-based conductive polymer film in an aqueous solution and its metallization application. Through an electrochemical polymerization reaction, a high-stability, low-cost thiophene-based conductive polymer film is successfully synthesized in an aqueous solution, and the film is used as a basis for metal electrodeposition to achieve efficient metallization of the polymer surface. The present invention overcomes the limitations of traditional metallization methods by optimizing the electrosynthesis conditions, significantly improves the metal deposition rate and adhesion, and provides a new technical approach for the metallization application of conductive polymers.

[0005] To achieve the above-mentioned purpose of the invention, the technical solution of the present invention is as follows:

[0006] A method for electrosynthesizing a thiophene-based conductive polymer film in an aqueous solution comprises the following steps:

[0007] (1.1) preparing an electrolyte solution, dissolving one or more monomers of thiophene and its derivatives in an acidic aqueous solution under magnetic stirring to obtain a uniform aqueous electrolyte solution;

[0008] (1.2) Electrochemical synthesis of conductive polymer film: first pre-treat the surface of the working electrode, then use the aqueous electrolyte prepared in (1.1) in a three-electrode system to electrochemically polymerize on the surface of the working electrode to form a conductive polymer film of thiophene or thiophene-based system by cyclic voltammetry.

[0009] As a preferred embodiment, the purity of the thiophene derivative monomer used is greater than 99.5%; the molecular formula of thiophene and its derivative monomers is C4H3S-R as follows:

[0010] Wherein R is selected from hydrogen, chlorine, bromine, methyl, ethyl, hydroxyl, and thiol, and the concentration of the thiophene derivative monomer is 5 to 50 mM.

[0011] As a preferred embodiment, the acidic solution in the aqueous electrolyte component of step (1.1) is composed of one or more of hydrochloric acid, nitric acid, sulfuric acid, perchloric acid and one or more water-soluble metal salts corresponding to such acids, wherein the acid concentration is 100 to 500 mM, and the concentration of thiophene and its derivative monomers is 5 to 50 mM.

[0012] As a preferred embodiment, the three electrodes in step (1.2) are a glassy carbon electrode as a working electrode, a platinum sheet as a counter electrode, and a silver / silver chloride electrode as a reference electrode; the pretreatment steps of the glassy carbon electrode are: polishing with fine sandpaper, polishing with suede polishing cloth, ultrasonic cleaning with ethanol and deionized water, and then immersing the working electrode in a nitric acid solution for standby use.

[0013] As a preferred embodiment, the electrochemical polymerization method in step (1.2) is cyclic voltammetry, which is performed by cyclically scanning between 0 and 2.5 V for 10 to 40 cycles to achieve the synthesis of the conductive polymer.

[0014] The second object of the present invention is to provide a metallization application of a conductive polymer film: the conductive polymer film prepared by the method is metallized in a metal plating solution using a constant potential method in a three-electrode system to form a metal layer deposition on the surface of the film.

[0015] As a preferred embodiment, the metallization application is further: a constant potential method under a three-electrode system, wherein the three electrodes are a glassy carbon electrode with a thiophene-based conductive polymer film as a working electrode, a platinum sheet as a counter electrode, and a reference electrode selected from a saturated mercurous sulfate electrode and a silver / silver chloride electrode. The polymerization conditions are polymerization for 3 to 10 minutes in a potential range of 1V to -1V, and the formed metal layer includes one or more alloys of copper, silver, nickel, tin, gold, and palladium.

[0016] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in:

[0017] (1) Aqueous solution electrosynthesis technology: Compared with the traditional organic solvent electrosynthesis method, the present invention provides an environmentally friendly and low-cost new technology for aqueous solution electrosynthesis of thiophene-based conductive polymer films, which has great environmental and economic benefits.

[0018] (2) Metal electrodeposition without the need for chloride ions: Traditional metal electrodeposition relies on the presence of chloride ions. However, the present invention, through the interaction between bis-(3-sulfopropyl) disulfide and conductive polymer, can still achieve efficient metal electrodeposition on the surface of thiophene-based conductive polymers even in the absence of chloride ions, greatly expanding the application scope of conductive polymer metallization processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a circuit diagram of the method for electrosynthesis of thiophene-based conductive polymer film in aqueous solution and metallization;

[0020] Figure 2 The results of the film stability test prepared in Example 1;

[0021] Figure 3 Time-current curve of the polythiophene film metallized copper prepared in Example 3.

[0022] Figure 4 Comparison of the polythiophene film prepared in Example 3 before and after copper metallization. DETAILED DESCRIPTION

[0023] The present invention is described in detail below in conjunction with specific implementation cases and drawings. It is necessary to point out that the following implementation cases are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the content of the present invention still fall within the scope of protection of the present invention.

[0024] The raw materials used in the examples are all conventional commercially available raw materials and do not require further purification.

[0025] The embodiment provides a method for electrosynthesizing a thiophene-based conductive polymer film in an aqueous solution, comprising the following steps:

[0026] (1.1) preparing an electrolyte solution, dissolving one or more monomers of thiophene and its derivatives in an acidic aqueous solution under magnetic stirring to obtain a uniform aqueous electrolyte solution;

[0027] (1.2) Electrochemical synthesis of a conductive polymer film: in a three-electrode system, using the aqueous electrolyte prepared in (1.1), electrochemically polymerizing on the surface of the working electrode to form a thiophene or thiophene-based conductive polymer film by cyclic voltammetry.

[0028] Preferably, the purity of the thiophene derivative monomer used is greater than 99.5%; the molecular formula of thiophene and its derivative monomers C4H3S-R is as follows:

[0029] Wherein R is selected from hydrogen, chlorine, bromine, methyl, ethyl, hydroxyl, and thiol, and the concentration of the thiophene derivative monomer is 5 to 50 mM.

[0030] Preferably, the acidic solution in the aqueous electrolyte component of step (1.1) is composed of one or more of hydrochloric acid, nitric acid, sulfuric acid, perchloric acid and one or more water-soluble metal salts corresponding to such acids, wherein the acid concentration is 100 to 500 mM, and the concentration of thiophene and its derivative monomers is 5 to 50 mM.

[0031] Preferably, in step (1.2), the three electrodes are a glassy carbon electrode as a working electrode, a platinum sheet as a counter electrode, and a silver / silver chloride electrode as a reference electrode; the pretreatment steps of the glassy carbon electrode are: polishing with fine sandpaper, polishing with suede polishing cloth, ultrasonic cleaning with ethanol and deionized water, and then immersing the working electrode in a nitric acid solution for standby use.

[0032] Preferably, the electrochemical polymerization method in step (1.2) is cyclic voltammetry, which cyclically scans between 0 and 2.5 V for 10 to 40 cycles to achieve the synthesis of the conductive polymer.

[0033] The embodiment also provides a metallization application of a conductive polymer film, wherein the conductive polymer film is metallized in a metal plating solution using a constant potential method in a three-electrode system to form a metal layer deposition on the surface of the film.

[0034] Furthermore, the metallization application of the conductive polymer film is a constant potential method under a three-electrode system, wherein the three electrodes are a glassy carbon electrode with a thiophene-based conductive polymer film as a working electrode, a platinum sheet as a counter electrode, and a reference electrode selected from a saturated mercurous sulfate electrode and a silver / silver chloride electrode. The polymerization conditions are that the polymerization is carried out in a potential range of 1V to -1V for 3 to 10 minutes, and the formed metal layer includes one or more alloys of copper, silver, nickel, tin, gold, and palladium.

[0035] Example 1

[0036] Embodiment 1 provides a method for electrosynthesizing a polythiophene film in an aqueous solution, comprising the following steps:

[0037] (1.1) preparing an electrolyte solution by dissolving a thiophene monomer in an aqueous solution containing perchloric acid under magnetic stirring to obtain an aqueous electrolyte solution;

[0038] The purity of the thiophene monomer used is greater than 99.5%; the molecular formula of the thiophene monomer is as follows:

[0039]

[0040] Preferably, the aqueous electrolyte in step (1.1) contains 5 to 50 mM thiophene monomer and 100 to 500 mM perchloric acid per 100 ml of aqueous solution.

[0041] (1.2) Pre-treat the working electrode surface by polishing the electrode surface and using ultrasonic and acid washing methods to remove surface grease and fingerprint contaminants;

[0042] Preferably, in step (1.2), the working electrode is a glassy carbon electrode, and the pretreatment steps are: first polish with 7000 mesh fine sandpaper for 5 minutes, then polish with 0.05 μm alumina polishing powder on a suede polishing cloth for 5 minutes, and then ultrasonicate in ethanol and deionized water for 1 minute respectively, and then immerse the working electrode in 3M nitric acid solution for standby use.

[0043] (1.3) Under a three-electrode system, the aqueous electrolyte prepared in (1.1) is used to electrochemically polymerize the surface of the working electrode pretreated in (1.2) to form a conductive polythiophene film;

[0044] Preferably, the three electrodes in step (1.3) are a glassy carbon electrode as a working electrode, a platinum sheet as a counter electrode, and a silver / silver chloride electrode as a reference electrode, and all electrodes are soaked in 3 mol / L nitric acid before use.

[0045] Preferably, the electrochemical polymerization method in step (1.3) is cyclic voltammetry, with 20 cycles of scanning between 0 and 2.5 V at a scanning rate of 100 mV / S.

[0046] (1.4) Metallic copper was deposited on the polythiophene film prepared by (1.3) using a constant potential method and a three-electrode system.

[0047] Preferably, the copper electroplating solution in step (1.4) consists of 100 to 200 g / L copper sulfate pentahydrate, 50 to 100 g / L sulfuric acid and 10 to 200 ppm of a solution of bis-(3-sulfopropyl) disulfide.

[0048] Preferably, the three electrodes in the constant potential method under the three-electrode system of step (1.4) are a glassy carbon electrode with a polythiophene film as a working electrode, a platinum sheet as a counter electrode, and a saturated mercurous sulfate electrode as a reference electrode. The polymerization conditions are polymerization at a potential of -0.3V to -0.9V for 3 to 10min.

[0049] Example 2

[0050] This embodiment provides a method for electrosynthesizing a polythiophene film in an aqueous solution, comprising the following steps:

[0051] Step 1: Preparation of aqueous electrolyte

[0052] Under magnetic stirring, 10 to 100 mM thiophene monomer (purity greater than 99.5%, without further purification, sourced from MacLean) was dissolved in 100 mL of an aqueous solution containing 100 mM perchloric acid to obtain an aqueous electrolyte.

[0053] Step 2: Electrode pretreatment

[0054] The electrode surface was polished with 7000-grit fine sandpaper for 5 min, and then polished with 0.05 μm aluminum oxide polishing powder on a suede polishing cloth for 5 min to ensure that the electrode surface was smooth and clean. After treatment, the electrode was cleaned with deionized water, and ultrasonically cleaned in ethanol and deionized water for 1 min each, and finally immersed in 3M nitric acid solution.

[0055] Step 3: Electrochemical synthesis

[0056] In the three-electrode system (glassy carbon electrode as working electrode, platinum sheet as counter electrode, Ag / Ag + The electrode is a reference electrode), and the aqueous electrolyte is used to electrochemically polymerize the pretreated working electrode surface to form a conductive polythiophene film. The electrochemical polymerization uses cyclic voltammetry (CV) and cyclically scans 10 to 40 times in the potential range of 0 to 2.5 V at a scanning speed of 100 mV / s.

[0057] The stability test of the film prepared in this example is as follows Figure 2 The anodic oxidation curves obtained after 1 and 100 cyclic voltammetry scans of the polythiophene interface are basically the same, which proves that the prepared polythiophene film has good electrochemical stability.

[0058] Example 3

[0059] This embodiment provides a metallization application of electrosynthesized polythiophene film in an aqueous solution, comprising the following steps:

[0060] Step 1: Electrolyte preparation

[0061] Weigh 100 to 200 g / L of copper sulfate pentahydrate (CuSO4·5H2O) and dissolve it in an appropriate amount of deionized water, stirring thoroughly until completely dissolved. Next, add 50 to 100 g / L of sulfuric acid (H2SO4) to adjust the acidity of the electrolyte and continue to stir evenly. Finally, add 10 to 200 ppm of bis-(3-sulfopropyl) disulfide to the solution as an additive for the electroplating process to ensure that it is completely dissolved. The entire preparation process should be carried out at room temperature to ensure the uniformity and stability of the electrolyte, and finally obtain a solution suitable for copper electroplating.

[0062] Step 2: Constant Potentiostatic Copper Deposition

[0063] The polythiophene film was prepared on a glassy carbon electrode using the method of Example 1, and the glassy carbon electrode on which the polythiophene (PTh) film had been prepared was selected as the working electrode. The electrode surface was cleaned to ensure that there was no oil or contaminants on the surface. A platinum sheet was used as the counter electrode, and a saturated mercurous sulfate electrode (Hg / Hg2SO4) was used as the reference electrode.

[0064] Connect the three-electrode system to the electrochemical workstation. Add the electrolyte to the electroplating tank, making sure that the electrolyte covers all electrodes. Electrodeposit copper at a constant potential of -0.7V. Maintain this potential and perform the electroplating process for 3 to 10 minutes. After the electroplating is completed, remove the working electrode, rinse it with deionized water, and dry it naturally. At this point, the copper metal layer has been evenly deposited on the surface of the PTh film for further characterization and application.

[0065] The time-current curve of the polythiophene film prepared in this example after metallization is shown in FIG. Figure 3 As shown, the comparison before and after metallization is Figure 4 shown.

[0066] Example 4

[0067] The difference between this embodiment and embodiment 2 is that the thiophene monomer in embodiment 1 is replaced by 3,4-ethylenedioxythiophene monomer, that is, a poly 3,4-ethylenedioxythiophene film is formed, and the poly 3,4-ethylenedioxythiophene is copper metallized by the same copper plating process as in embodiment 2.

[0068] Example 5

[0069] The difference between this embodiment and embodiment 3 is that the electroplating solution in embodiment 2 is prepared by replacing copper sulfate pentahydrate and sulfuric acid with silver nitrate (AgNO3) and sodium thiosulfate (Na2S2O3), and the polythiophene film is metallized while other conditions remain unchanged.

[0070] Example 6

[0071] The difference between this embodiment and embodiment 3 is that the electroplating solution in embodiment 2 is prepared by replacing copper sulfate pentahydrate and sulfuric acid with nickel sulfate (NiSO4·6H2O) and nickel chloride (NiCl2·6H2O), and the polythiophene film is metallized while other conditions remain unchanged.

Claims

1. A method for electrosynthesizing a thiophene-based conductive polymer film in an aqueous solution, characterized in that The steps include: (1.1) preparing an electrolyte solution, dissolving one or more monomers of thiophene and its derivatives in an acidic aqueous solution under magnetic stirring to obtain a uniform aqueous electrolyte solution; (1.2) Electrochemical synthesis of a conductive polymer film: in a three-electrode system, using the aqueous electrolyte prepared in (1.1), electrochemically polymerizing on the surface of the working electrode to form a thiophene or thiophene-based conductive polymer film by cyclic voltammetry.

2. The method for electrosynthesizing a thiophene-based conductive polymer film in an aqueous solution according to claim 1, characterized in that: The purity of the thiophene derivative monomer used is greater than 99.5%; the molecular formula of thiophene and its derivative monomers is C4H3S-R as follows: Wherein R is selected from hydrogen, chlorine, bromine, methyl, ethyl, hydroxyl, and thiol, and the concentration of the thiophene derivative monomer is 5 to 50 mM.

3. The method for electrosynthesizing a thiophene-based conductive polymer film in an aqueous solution according to claim 1, characterized in that: The acidic solution in the aqueous electrolyte component described in step (1.1) is composed of one or more of hydrochloric acid, nitric acid, sulfuric acid, perchloric acid and one or more water-soluble metal salts corresponding to such acids, wherein the acid concentration is 100 to 500 mM, and the concentration of thiophene and its derivative monomers is 5 to 50 mM.

4. The method for electrosynthesizing a thiophene-based conductive polymer film in an aqueous solution according to claim 1, characterized in that: In step (1.2), the three electrodes are a glassy carbon electrode as a working electrode, a platinum sheet as a counter electrode, and a silver / silver chloride electrode as a reference electrode; the pretreatment steps of the glassy carbon electrode are: polishing with fine sandpaper, polishing with suede polishing cloth, ultrasonic cleaning with ethanol and deionized water, and then immersing the working electrode in a nitric acid solution for standby use.

5. The method for electrosynthesizing a thiophene-based conductive polymer film in an aqueous solution according to claim 1, characterized in that: The electrochemical polymerization method of step (1.2) is cyclic voltammetry, which scans cyclically between 0 and 2.5 V for 10 to 40 cycles to achieve the synthesis of the conductive polymer.

6. A metallization application of a conductive polymer film, characterized in that: The conductive polymer film prepared by the method according to any one of claims 1 to 5 is metallized in a metal plating solution using a constant potential method in a three-electrode system to form a metal layer deposition on the surface of the film.

7. The metallization application according to claim 6, characterized in that: A constant potential method under a three-electrode system, wherein the three electrodes are a glassy carbon electrode with a thiophene-based conductive polymer film as a working electrode, a platinum sheet as a counter electrode, and a reference electrode selected from a saturated mercurous sulfate electrode and a silver / silver chloride electrode. The polymerization conditions are polymerization for 3 to 10 minutes within a potential range of 1V to -1V, and the formed metal layer includes one or more alloys of copper, silver, nickel, tin, gold, and palladium.

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