Conductive plastic

Introduction

Most of the conductive plastic is originally an insulating material to mix high concentrations of filamentous carbon black and fully coking compounds. The volume resistivity and the surface resistivity are also sufficient to describe their electrical properties. This electrical performance of such relocated charcoal network structures depends on the methods of preparing their, and also varies with the change of mechanical bending and exposure.

The conductive plastic combines the conductivity of the metal (i.e., a certain amount of voltage is added to the material, and there is currently passed the various characteristics of the plastic (ie, the material molecule is made up of many small, repetition The structural unit that appears is composed. To give a polymer in conductivity, the π conjugate system must be introduced in the polymer main chain, constitute a high molecule of the π-electron-overlapping polymer, and the liquid conventional structure of the polymer is also indispensable, and the dopant can Sheng this. Therefore, the first condition having a conductivity of the plastic material is that it must have a conjugated π electron system, and the second condition must be chemically or electrochemically doped, i.e., by the redox process, the polymer chain is obtained or lost. electronic. Research progress shows that people can produce plastics that have exceeded copper, as well as plastics that exceed other materials at room temperature.

Source

We generally believe that the plastic conductivity is extremely poor, so that the insulating jacket used to make a wire. However, Australian researchers have found that when a thin metal film is covered with a layer of plastic layer, and it is mixed into a polymer polymer surface by means of ion beam, it will produce a low price, high strength, toughness. Good and electrically conductive plastic film.

The group obtained by two experts from the University of Queensland, Australia, is Paul Meredith Professor and Assistant Professor Bowell, and one Professor Adam Micolich from Adam Micolica from the University of New South Wales University. Their results have been published in "Chemphyschem" magazine. The study was conducted by the experiment of the former Queensland University Dr. Andrew Stephenson. Ion beam technology is widely used in the field of microelectronic industries to test semiconductors, such as conductive properties of silicon wafers. However, the attempt to apply this technology to a plastic film material is from the 1980s, it has been in great progress. Professor Mairi introduced: "The work made by this group is simply to change the nature of the plastic film material by means of ion beam technology, so that it has a function of similar metals, which can be electrically conductive to the wire itself, and can even become superconductors. When the temperature is low to a certain extent, the electric resistance becomes zero. "

In order to show the potential application value of this material, the team adopts this material, and the resistance thermometer is made with reference to the industrial standard. When comparing the same type of platinum resistance thermometer, the product made of new materials shows similar, even superior performance. "This kind of material is interesting to reserve all the advantages of polymer polymers - mechanical flexibility, high strength, low cost, but at the same time it has good conductivity, and this is usually not Plastics should have the characteristics. "Professor Mi Coyfore said. "This material created a new sky of a plastic conductor."

Andrew Stephenson believes that this technology is the most exciting thing in this film, the conductivity of this film can be accurately adjusted or set. Set, this will have a very broad application prospect. He said: "In fact, we can change the conductivity of this material to 10 orders of order, simply, like we have 10 billion choices when making this material. Theoretical, we A completely non-conductive plastic can be manufactured, or a good conductivity and metal, and all the possibilities between the two can be produced. "

This new material can utilize the microelectronics industry commonly used The equipment is easily manufactured, and it is much higher than the traditional polymer semiconductor material, which is much higher than the antioxidant capacity exposed to oxygen. The researchers said that the above advantages of the above advantages, such a film material obtained by ion beam treatment of polymer polymers will have a broad application prospect, which is a fusion of modern and future technologies.

Classification

Conductive plastic is usually divided into two categories.

Structural conductive plastic

means that the plastic itself has "inherent" conductivity, providing a conductive carrier (electron, ion or holes) by the polymer structure. Such plastics have been doped, and the conductivity can be greatly improved, and some can even achieve the conductivity level of the metal. Doped methods have chemical doping and physically doped two-class, dopants having electron acceptors, electron donors, and electrochemical dopants. Doped polyacetylene is a typical example in which the electrical conductivity can be increased to 10 ⁴ ω ^-1 · cm ^-1 · cm ^-1 · cm SUP> -1 .

Structured conductive plastic can be used to make high-power plastic batteries, high energy density capacitors, microwave absorbing materials, and the like.

Composite conductive plastic

In the composite conductive plastic, the plastic itself does not have electrical conductivity, only the role of the binder. The conductivity is obtained by mixing conductive substances such as carbon black, metal powder or the like. These conductive substances are called conductive fillers, with maximum silver powder and carbon black, which plays a function of providing carriers in composite conductive plastics.

Composite conductive plastic is convenient, strong practical, often applied to switches, pressure sensitive components, connector, antistatic materials, electromagnetic shielding materials, resistors, and solar cells.

Purpose

Conductive plastic is not only rapidly developed in anti-static additives, computer anti-electromagnetic screens and smart windows, but also in light-emitting diodes, solar batteries, mobile phones, Mini TV screens and even life scientific research have extensive application prospects. In addition, the combination of conductive plastics and nanotechnology will also play a rapid development of molecular electronics. In the future, mankind not only greatly improves the computer's computing speed, but also reduces the volume of the computer. Therefore, some people predict that future laptops can be loaded into the watch.

With the rapid development of electronics, integrated circuits, and large-scale integrated circuits, including miniaturization and high speed, the current used is mostly weak current, resulting in control signal power and external intrusion electromagnetic wave noise Close, therefore is easy to generate malfunctions, image barriers, and audio barriers, obstructing police communication, defense communications, and aviation communications, causing satellite assembly debugging obstacles, and shielding measures must be used. The conductive plastic is an ideal shield material that can be shielded as the outer casing of the electronic device device. It is more lightweight, easy to adjust, corrosion resistant, and the total cost is relatively low compared to traditional conductive materials, and there is a low cost, so it is necessary to achieve shielding with conductive plastic.

Many conductive materials or highly conductive materials, such as production electrodes, low temperature heating, and the like, to use conductive plastics.

New Conductive Plastics

South Korea Science and Technology Institute recently obtained electrically conductive plastics after chemical polymerization of polypyrrole. This is an energy storage, which can be applied to a high molecular battery according to its repeated redox effect according to its in the film, and it can be used to produce a discoloration switch can also be covered with a semiconductor electrode of the solar cell. To improve performance can also be used for circuit design, or instead of existing batteries and for fax photos.