The surface of the bonded polyimide film insulating material will spontaneously form an electric double layer

The researchers chose potassium tantalate, which is very chemically stable and has few impurities, as the insulating material, and then placed the solid insulating material in an ionic liquid. The surface of the bonded polyimide film insulating material will spontaneously form an electric double layer. Under this electric field effect, the insulating material becomes superconductive, achieving zero resistance at an absolute temperature of 0.05°C (minus 273.1°C).

It is reported that so far, the research and development of superconducting materials has mainly adopted two methods, one is a metallurgical method in which a variety of metals are mixed, and the other is a chemical method in which impurities are mixed with insulators as the main material, the most representative of which is oxidation. Copper high temperature superconducting material.

The method of using electric field effect this time can be described as a new way to develop superconducting materials. It can make substances such as potassium tantalate that were originally considered not superconducting materials superconducting, laying the foundation for the development of new superconducting materials with higher critical temperatures in the future.

1. Insulation resistance and resistivity

Resistance is the reciprocal of conductance and resistivity is the resistance per unit volume. The lower the conductivity of the material, the higher the resistance. There is an inverse relationship between the two. For insulating materials, the resistivity is always desired to be as high as possible.

2. Relative permittivity and dielectric loss tangent

Insulating materials serve two purposes: mutual insulation of parts of the grid and dielectric (energy storage) for capacitors. The dielectric constant required by the former is relatively small, while the dielectric constant required by the latter is relatively large, and both require a small dielectric loss tangent, especially for insulating materials used under high frequency and high voltage. In order to reduce the dielectric loss, an insulating material with a small dielectric loss tangent is required.

3. Breakdown voltage and electrical strength

Under the action of a strong electric field, the insulating material is destroyed, loses its insulating properties and becomes conductive, which is called breakdown. The voltage at breakdown is called breakdown voltage (dielectric strength). The electrical strength is the quotient of the voltage at which breakdown occurs under specified conditions and the distance between the two electrodes subjected to the applied voltage, that is, the breakdown voltage per unit thickness. For insulating materials, the higher the breakdown voltage and electrical strength, the better.

4. Tensile strength

is the maximum tensile stress experienced by the specimen during the tensile test. It is the most widely used and most representative test method for the mechanical properties of insulating materials.

5. Fire resistance

Refers to the ability of an insulating material to resist burning when in contact with a flame or prevent further burning when leaving it. With the increasing application of insulating materials, the requirements for their flame resistance are becoming more and more important. People improve and improve the flame resistance of insulating materials by various means. The higher the combustion resistance, the better the safety.

6. Arc resistance

The ability of an insulating material to withstand the action of an electric arc along its surface under specified test conditions. In the test, AC high voltage and small current are used, and the arc resistance of the insulating material is judged by the time required to form a conductive layer on the surface of the insulating material through the arc action generated by the high voltage between the two. electrode. The larger the time value, the better the arc resistance.

7. Sealing degree

Good sealing and isolation of oil and water quality.