Method for preparing electroconductive polymer and thermoelectric device comprising electroconductive polymer film prepared using the same
There are provided a method for producing an electroconductive polymer which can be operated at a low temperature such as the human body temperature, is safe to the human body, and is flexible and useful as a thermoelectric material, and a thermoelectric element including a thin film of an electroconductive polymer produced by the production method.
1. A method for producing an electroconductive polymer, the method comprising:
a step of preparing an oxidizing solution including an oxidizing agent, a polymerization retarder, a copolymer containing a polyalkylene glycol as a constituent unit, and a solvent; and
a step of polymerizing an electroconductive polymer by adding a monomer for forming an electroconductive polymer to the oxidizing solution and performing solution polymerization, or by applying the oxidizing solution to form a coating film, subsequently supplying the vapor of a monomer for forming an electroconductive polymer to the coating film, and performing vapor polymerization.
2. The method for producing an electroconductive polymer according to claim 1 , wherein the oxidizing agent is selected from the group consisting of ammonium persulfate, DL-tartaric acid, polyacrylic acid, copper chloride, ferric chloride, iron toluenesulfonate, β-naphthalenesulfonic acid, p-toluenesulfonic acid, camphorsulfonic acid, and mixtures thereof.
3. The method for producing an electroconductive polymer according to claim 1 , wherein the oxidizing agent is included at a proportion of 5% to 50% by weight relative to the total weight of the oxidizing solution.
4. The method for producing an electroconductive polymer according to claim 1 , wherein the polymerization retarder is a basic substance having a pKa value of 3.5 to 12.
5. The method for producing an electroconductive polymer according to claim 1 , wherein the polymerization retarder is included at a molar ratio of 0.1 to 2 with respect to 1 mole of the oxidizing agent.
6. The method for producing an electroconductive polymer according to claim 1 , wherein the copolymer is a copolymer containing one or more selected from polyethylene glycol and polypropylene glycol as constituent units.
7. The method for producing an electroconductive polymer according to claim 1 , wherein the copolymer is a triblock copolymer of polyethylene glycol-polypropylene glycol-polyethylene glycol.
8. The method for producing an electroconductive polymer according to claim 1 , wherein the copolymer has a weight average molecular weight of 500 to 1,000,000 g/mol.
9. The method for producing an electroconductive polymer according to claim 1 , wherein the copolymer is included at a proportion of 5% to 40% by weight relative to the total weight of the oxidizing solution.
10. The method for producing an electroconductive polymer according to claim 1 , wherein the solvent is selected from the group consisting of an alcohol-based compound, tetrahydrofuran, dioxin, chloroform, methylene chloride, acetone, methyl ketone, tetrachloroethane, toluene, and mixtures thereof.
11. The method for producing an electroconductive polymer according to claim 1 , wherein the oxidizing solution further includes an additive selected from the group consisting of a polyalkylene glycol, an oxidation inhibitor, a thermal stabilizer, a thickener, and mixtures thereof.
12. The method for producing an electroconductive polymer according to claim 1 , wherein after polymerization of the electroconductive polymer, a doping amount of the electroconductive polymer is regulated by an electrochemical method of using the polymerized electroconductive polymer as an electrode and applying a voltage thereto in an electrolyte solution.
13. An electroconductive polymer produced by the production method according to claim 1 .
14. The electroconductive polymer according to claim 13 , having an electrical conductivity of 500 S/cm or more.
15. A thermoelectric element comprising a thin film of an electroconductive polymer produced by the production method according to claim 1 .
16. The thermoelectric element according to claim 15 , wherein the thermoelectric element comprises a substrate; and disposed on the substrate, the thin film of an electroconductive polymer as a p-type material.
17. The thermoelectric element according to claim 15 , further comprising a thin film of an organic substance or an inorganic semiconductor, which is disposed on the substrate and is a n-type material that is electrically coupled with the thin film of the electroconductive polymer.
18. The thermoelectric element according to claim 15 , wherein the substrate has flexibility.