JPH07179576A - Production of organic conductor and organic conductor produced by the process - Google Patents

Abstract

PURPOSE:To easily obtain an organic conductor having anisotropic electrical conductance and useful as electrode, optical function element, cell, etc., by carrying out electrolytic polymerization in the presence of magnetic field having a specific magnetic field intensity. CONSTITUTION:This conductor is produced by carrying out the electrochemical polymerization of a monomer and/or oligomer (preferably thiophene) in an electrolytic solution on the surface of an electrode in the presence of magnetic field having a field intensity of >=1Oe, preferably >=1.3T. Concretely, an electrolyte solution is prepared by using thiophene as the monomer, tetrabutylammonium tetrafluoroborate as the electrolyte and propylene carbonate as the solvent, dipping a working electrode composed of platinum and a counter electrode composed of copper into the electrolyte solution and applying a potential of 5V to the electrode pair while applying a magnetic field of 1,500Oe with a permanent magnet perpendicular to the direction of the electric field. A thin film of polythiophene is formed on the working electrode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an organic conductor, more specifically, a high-strength organic conductor useful for electrodes, optical functional devices, batteries, nonlinear optical materials, various sensors, electromagnetic shields, FETs and the like. Regarding the method.

[0002]

2. Description of the Related Art The synthesis of an organic conductor is carried out by a chemical polymerization method in which a monomer is polymerized using an oxidant or a catalyst, a method in which an intermediate made of a non-conjugated polymer is heat-treated, an electrolytic polymerization method and the like. Has been. Here, the electrolytic polymerization method means that the working electrode and the counter electrode, and if necessary, the reference electrode are immersed in an electrolytic solution containing a monomer (or an oligomer) and a supporting electrolyte, and a voltage is applied to the monomer so that the monomer is electrochemically reacted. A polymer that can be easily obtained by electrolytic oxidation or electrolytic reduction on the electrode surface to generate in situ reactive reactive species such as cation radicals and anion radicals, which are polymerized into a polymer. Since it also has a high conductivity, it is also suitable for actual manufacturing and application.

However, some of the organic conductors synthesized by the electrolytic polymerization method are insufficient in physical properties such as electric conductivity and strength, and are not satisfactory in production such as yield. , The usable range was limited. Therefore, in order to improve the electric conductivity, a method of performing electrolytic polymerization while applying a magnetic field (Japanese Patent Laid-Open No. 64-79221),
In order to improve the yield, a method of carrying out electrolytic polymerization in the presence of a magnetic field that causes an electrolytic solution to flow (JP-A-3-190).
No. 922 and Japanese Patent Laid-Open No. 3-263424) have been proposed.

Regarding the physical properties of the organic conductor synthesized by the electrolytic polymerization method, for example, the polypyrrole thin film and the polythiophene thin film have a large difference in the electrical conductivity between the in-plane direction and the film thickness direction and exhibit anisotropy. (K. Kaneto et
al. Jpn. J. Appl. Phys., 21 , L567 (1982)] or when a polythiophene thin film is stretched, it exhibits anisotropic conductivity in the stretching direction and the direction perpendicular thereto (M. Satoh et al. Poly
m. Commun., 28 , 144 (1987)]. That is, in order to obtain anisotropy of conductivity in the in-plane direction in a thin film formed by electrolytic polymerization, an operation such as stretching of the thin film (film) is required.

[0005]

However, in order to form such a stretchable film, various electrolytic conditions are examined so that the film has sufficient strength so that the film is not broken during the stretching operation. There was a need.

Therefore, the present invention solves the above-mentioned problems and provides a method for easily producing an organic conductor having anisotropic conductivity,
Another object of the present invention is to provide an organic conductor having anisotropic conductivity produced by the method.

[0007]

According to the present invention, in an electrolytic solution containing a monomer and / or an oligomer, an electrochemical polymerization reaction is caused to occur on the surface of an electrode on the monomer and / or oligomer in the electrolytic solution. The reaction is 1
Provided is a method for producing an organic conductor having anisotropic conductivity, which is performed in the presence of a magnetic field of Oe or more, and an organic conductor having anisotropic conductivity formed by the method. It

In the present invention, since the monomer and / or oligomer is electrochemically polymerized in the electrolytic solution in the presence of a magnetic field of 1 Oe or more, an organic conductor having anisotropic conductivity can be easily prepared. Will be obtained. Incidentally, the above-mentioned JP-A-64-79221 and JP-A-3-190.
No. 922 and JP-A-3-263424 describe that electrolytic polymerization is carried out while applying a magnetic field. Regarding the anisotropy of electric conductivity of the obtained organic conductor,
Not touched at all.

Hereinafter, the method for producing an organic conductor of the present invention and the organic conductor obtained by the method will be described in detail. The method of the present invention is characterized in that an organic conductor having anisotropic conductivity is formed by carrying out electrolytic polymerization in a magnetic field. When the applied magnetic field strength is less than 1 Oe (Oersted), the magnetic field strength is almost the same as that of the earth's magnetism, and the effect is not observed. Here, the application of the magnetic field is
For example, any permanent magnet or a permanent magnet incorporated in a magnetic circuit, a Helmholtz coil, a solenoid coil, an electromagnet, a superconducting magnet, or any other magnetic field that can generate a magnetic field may be used. Of course, both the stationary magnetic field and the pulsed magnetic field can be used.

Generally, when a charged particle having an electric charge e moves in a magnetic field having a magnetic flux density B at a velocity V, a Lorentz force F acts in a direction perpendicular to both the magnetic field direction and the charged particle moving direction. The size can be expressed by F = eV × B. That is,
The magnitude of Lorentz force is proportional to the magnetic field strength. When an organic conductor is formed by electrolytic polymerization in a magnetic field, the charged particles in the electrolytic solution start to receive the Lorentz force at the same time as the voltage is applied. As a result of intensive studies by the present inventor, the organic conductor formed by electrolytic polymerization in a magnetic field has a difference in electric conductivity between the direction in which the Lorentz force acts and other directions during formation, and the magnetic field strength is increased. It was found that the difference in electrical conductivity becomes remarkable. In particular, when the magnetic field strength is set to a strong magnetic field of 1.3 T or more, the Lorentz force also becomes very large, so that the anisotropic conductivity remarkably appears, and it is possible to easily perform the conventional operations such as stretching and the like. It becomes possible to form an organic conductor having anisotropic conductivity.

Examples of the monomer or oligomer used in the present invention include aromatic compounds containing amino acids or hydroxyl groups, heterocyclic compounds, benzene and 2
Many substances such as polycyclic hydrocarbon compounds having one or more condensed aromatic rings, compounds having a vinyl group, acetylene and derivatives thereof can be used. Further, when thiophene and its derivative are used as the monomer here, the above-mentioned effects are remarkably observed.

As the solvent for dissolving these monomers or oligomers, for example, aprotic solvents such as acetonitrile, benzonitrile, propylene carbonate, protic solvents such as methanol and ethanol, water and many others are used. can do.
Further, as the electrolyte, for example, LiBF ₄ , LiCl
Many substances can be used, including O ₄ , LiPF ₆ , LiAsF ₆ , p-toluenesulfonate, and m-nitrobenzenesulfonate, and depending on the type of monomer to be polymerized and the conditions of polymerization, these substances can be used. An appropriate combination of is selected as the electrolytic solution.

When the above electropolymerization is carried out by electrolytic oxidation, for example, an aromatic compound containing an amino acid or a hydroxyl group, a heterocyclic compound, benzene and a polycyclic system having two or more condensed aromatic rings. Since a large number of monomers such as hydrocarbon compounds and compounds having vinyl groups can be polymerized, typical organic conductor monomers such as polythiophene, polypyrrole, polyaniline, polyparaphenylene, polyazulene, and polypyrene are used. it can.

The shape of the organic conductor formed by the above-described manufacturing method is various electrolysis conditions, the material and shape of the electrodes to be used, the distance between electrodes, the electrode (or electrode pair).
Various things can be obtained according to the direction of the applied magnetic field with respect to. In particular, when this shape is a film or a thin film (usually obtained when the electrode pair is a parallel plate), not only can it itself be a functional material, but it can also be combined with other materials or bonded. Since it becomes easy, it can be applied to various fields such as electric fields, optical fields, energy fields, and chemical fields by utilizing the advantage of having anisotropic conductivity.

[0015]

EXAMPLES The present invention will be described below with reference to examples, but the embodiments of the present invention are not limited thereby.

Example 1 An electrolyte solution was prepared by using thiophene (0.1M) as a monomer, tetrabutylammonium tetrafluoroborate (0.1M) as an electrolyte, and propylene carbonate as a solvent. The electrolytic cell is filled with this electrolytic solution, and a working electrode (anode) made of platinum and a counter electrode (cathode) made of copper
The electrode pair of was immersed. By applying a voltage of 5 V to this electrode pair and polymerizing thiophene on the working electrode,
A polythiophene thin film was formed. At this time, the magnetic field is applied so as to be perpendicular to the direction of the electric field using a permanent magnet,
The magnetic field strength was 1,500 Oe. For comparison, the polythiophene thin film was formed also in the case where no magnetic field was applied.

After the completion of electrolytic polymerization, the polythiophene thin film was peeled from the working electrode, doped with I ₂ , and the conductivity measured by the 4-terminal method is shown in Table 1. F‖ indicates the direction in which the Lorentz force acts, and F⊥ indicates the electric conductivity in the direction perpendicular to it (both in the film plane). When the magnetic field is not applied, the Lorentz force does not work, but when the magnetic field is applied, the electric conductivity in the directions corresponding to F / and F / is measured.

[0018]

[Table 1]

From Table 1, there is no difference in conductivity depending on the direction when no magnetic field is applied, whereas when a magnetic field of 1,500 Oe is applied, the conductivity in the direction in which the Lorentz force acts is perpendicular to it. It turns out that it is bigger than the one.

Example 2 A magnetic field was applied using a superconducting magnet and the magnetic field strength was 1.3 T.
A polythiophene thin film was formed under the same conditions as in Example 1, except that the thickness was 8T. Table 2 shows the measurement results of the electric conductivity in each case (also shown in the case of no magnetic field).

[0021]

[Table 2]

From Table 2, when the magnetic field strength is 1.3 T or more,
It can be seen that the electric conductivity in the F‖ direction has a very large value as compared with that in the F⊥ direction, and shows remarkable anisotropic conductivity.

[0023]

In the method for producing an organic conductor according to the first aspect of the present invention, when the monomer and / or oligomer in the electrolytic solution undergoes an electrochemical polymerization reaction on the surface of the electrode, the reaction is performed in a magnetic field of 1 Oe or more. Since the structure is implemented in the presence, it is possible to manufacture an organic conductor having anisotropic conductivity.

In the method for producing an organic conductor according to the second aspect, since a constitution in which a polymerization reaction is caused by electrochemically performing electrolytic oxidation is added, a typical organic conductor monomer can be used. Is added.

In the method for producing an organic conductor according to the third aspect, since the strength of the magnetic field is 1.3 T or more, it is possible to produce an organic conductor having remarkable anisotropic conductivity.

In the method for producing an organic conductor according to claim 4, since the monomer and / or oligomer contains at least thiophene and / or its derivative,
Further, it becomes possible to manufacture an organic conductor having more remarkable anisotropic conductivity.

The organic conductor according to claim 5 has anisotropic conductivity, and is therefore extremely useful for electrodes, optical functional elements, batteries and the like.

The organic conductor according to claim 6 has a film shape or a thin film shape, and therefore has an effect of broadening the range of application.

Claims (6)

[Claims] 1. In an electrolytic solution containing a monomer and / or an oligomer, in causing an electrochemical polymerization reaction of the monomer and / or the oligomer in the electrolytic solution on the electrode surface, the reaction is performed in a magnetic field of 1 Oe or more. A method for producing an organic conductor having anisotropic conductivity, which is carried out in the presence. 2. The method for producing an organic conductor according to claim 1, wherein a polymerization reaction is caused by electrochemically performing electrolytic oxidation. 3. The method for producing an organic conductor according to claim 1, wherein the strength of the applied magnetic field is 1.3 T or more. 4. The method for producing an organic conductor according to claim 1, wherein the monomer and / or oligomer contains at least thiophene and / or a derivative thereof. 5. An organic conductor having anisotropic conductivity formed by the manufacturing method according to any one of claims 1 to 4. 6. The organic conductor according to claim 5, which has a film shape or a thin film shape.