Preparation method of flexible conductive composites insensitive to strain and temperature

Abstract

A method for preparing flexible conductive composites that are both insensitive to strain and temperature. The material has a double-layer conductive network inside, the inner layer is composed of conductive polymers, and the outer layer is composed of graphene films. The electrical conductivity of the material is insensitive to strain, with resistance change rates of 3.2%, 5.3%, and 12.3% at tensile strains of 30%, 50%, and 80%, respectively. The material is not sensitive to temperature changes. When the material temperature is increased from 25°C to 60°C, 120°C and 160°C, the resistance change rates are 1.5%, 1.6% and 2.1%, respectively; when the material temperature is decreased from 25°C to At ‑40°C, the resistance change rate is ‑2.5%. The double-layer conductive network prepared by the invention takes poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and graphene film as inner and outer conductive materials respectively; Conductive composites exhibit dual insensitivity to strain and temperature. The invention develops a new structure of the flexible conductive composite material, and opens a new door for the multifunctional application of the flexible conductive composite material.

Description

technical field [0001] The invention relates to the field of conductive materials, and relates to a preparation method of a flexible conductive composite material that is insensitive to both strain and temperature. Background technique [0002] With the progress of society and the development of science and technology, flexible wearable electronic devices that meet the requirements of all-weather use have gradually become a research hotspot. This requires that the conductive properties of the flexible conductive material are not disturbed by deformation and can remain stable in a wide temperature range. In recent years, a great deal of research has been directed towards developing conductive materials whose conductive properties are insensitive to strain. Among them, the method of pre-constructing a three-dimensional graphene network and then backfilling with a polymer is a representative process for preparing high-performance strain-insensitive flexible conductive composit...

AI Technical Summary

Problems solved by technology

First, the flexible polymer matrix and conductive materials such as graphene have a large difference in thermal expansion coefficient. When the temperature of the material increases or decreases, the matrix undergoes obvious expansion or contraction, which is manifested as stretching or shrinkage of the composite material at the macroscopic level. Compression deformation; while conductive materials such as graphene have a low expansion or shrinkage rate, resulting in a certain strain in the conductive network during the expansion or contraction of the matrix, which affects the number of contact points of the conductive network inside the matrix, and directly affects the overall conductivity of the composite material.

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