Multi-layer core shell structure graphene based dielectric elastomer composite material and preparation method

Abstract

The invention discloses a multi-layer core shell structure graphene based dielectric elastomer composite material and a preparation method, and belongs to the technical field of dielectric elastomer preparation. The composite material comprises an elastomer matrix, a cross-linking system and multi-layer core shell structure graphene based dielectric packing, wherein the multi-layer core shell structure graphene based dielectric packing is formed by coating the surface of high dielectric ceramic packing with a polydopamine layer, grafting the surface of the polydopamine layer with a graphene oxide layer and reducing the graphene oxide layer into a graphene layer. Dielectric elastomer is filled with a small amount of multi-layer core shell structure graphene based dielectric packing to prepare the dielectric elastomer composite material. The dielectric constant of the dielectric elastomer is effectively improved while low dielectric loss is kept, and the problems of high filling volume, large elasticity modulus of composite materials, high dielectric loss, low electric breakdown strength and the like of the ceramic packing for filling the elastomer.

Description

technical field [0001] The invention belongs to the technical field of dielectric elastomer preparation, and in particular relates to a multilayer core-shell structure graphene-based dielectric elastomer composite material and its preparation. Background technique [0002] Dielectric elastomers have the characteristics of large electro-induced deformation, short response time, small viscoelastic hysteresis loss, good flexibility and high conversion efficiency. They are mainly used in the fields of micro-robots, micro-aircraft, artificial muscles, and planar loudspeakers. At present, dielectric elastomers have problems such as low dielectric constant, large dielectric loss, and small electro-induced deformation. [0003] There are two main methods to increase the dielectric constant of dielectric elastomers: one is to add high-dielectric ceramic fillers. Although this method can effectively improve the dielectric constant of dielectric elastomers, the amount of particles adde...

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Problems solved by technology

[0003] There are two main methods to increase the dielectric constant of dielectric elastomers: one is to add high-dielectric ceramic fillers. Although this method can effectively improve the dielectric constant of dielectric elastomers, the amount of particles added is large, resulting in elastic mode Increased amount, many material defects, low electrical breakdown strength

The second is to add conductive fillers. This method is based on the percolation threshold theory. When the conductive filler reaches the percolation threshold, the dielectric constant is the largest; but when the amount of conductive filler reaches or exceeds the percolation threshold, the dielectric elastomer forms a conductive path. The dielectric loss is greatly increased, and the electrical breakdown strength is greatly reduced

This preparation method reduces the dielectric loss and improves the electrical breakdown strength, but the polydopamine insulating layer coated on the outer surface of graphene oxide will reduce the dielectric constant of the dielectric elastomer

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