Graphene-based dielectric elastomer composite material and preparation method thereof

Abstract

The invention relates to a graphene-based dielectric elastomer composite material and a preparation method thereof. The composite material comprises an elastomer base body, graphene oxide-based dielectric filler and a cross-linking system, wherein the graphene oxide-based dielectric filler is core-shell hybrid particles of flaky graphene oxide-coated nano carbon balls. The method disclosed by the invention utilizes phi-phi electron interaction and hydrogen-bond interaction to realize simple and effective self-assembling of graphene oxide and nano carbon balls, so that the core-shell hybrid particles of the graphene oxide-coated nano carbon balls are formed and then added into rubber emulsion; then, an in-situ thermal reduction method is used for reducing a shell layer into graphene, so that a three-dimensional isolated network structure of latex particles coated by core-shell hybrid particles is formed, and therefore, dispersion of the graphene oxide is improved, dosage of the graphene and elastic modulus of the composite material are effectively lowered, and electro-generated deformation performances are remarkably improved; the high-performance graphene-based dielectric elastomer composite material with great electro-generated deformation under low driving voltage is prepared, and when electric field strength is 2kV / mm, deformation amount can reach 3.06%.

Description

technical field [0001] The invention relates to a graphene-based dielectric elastomer composite material and a preparation method thereof. The dielectric elastomer composite material can obtain large electric deformation under low driving voltage, belongs to the field of electroactive polymers, and can be used for electroactive Development of polymer actuators. Background technique [0002] Polymeric elastomers have excellent mechanical deformation capabilities, that is, large deformations can be produced under small stresses, and unique high elasticity (such as short response time, small viscoelastic hysteresis), but most elastomers have small dielectric constants (generally less than 10), the induction of the external electric field is weak, and to obtain a large strain, a higher electric field strength needs to be applied, which often exceeds the electrical breakdown strength of the elastomer, and poses a certain threat to the safety of the human body or equipment, thus l...

AI Technical Summary

Problems solved by technology

However, the technical problem of this type of dielectric elastomer is that when the amount of conductive filler reaches or exceeds the percolation threshold, a conductive path will be formed, the dielectric loss will increase significantly, and the electrical breakdown strength will also decrease significantly, which will easily cause electrical breakdown.

Chinese patent application "High dielectric composite material containing carbon nanotubes and its preparation method" (patent application number 03104776.9), proposes a method using carbon nanotubes (CNT) and barium titanate (BaTiO 3 ) and organic polyvinylidene fluoride (PVDF) are prepared by a hot pressing method to prepare a dielectric composite material. Although the dielectric constant of the dielectric composite material can reach 450 at 100 Hz, the dielectric loss increases significantly near the percolation threshold. , leading to a decrease in the electrical breakdown strength of the material, making it difficult to obtain a large electro-induced deformation at low voltage

When the dielectric constant of this material is 689-10394 at 100 Hz, the dielectric loss is 0.49-2.02 at 100 Hz. However, due to the flaky graphene oxide filler used in this patent, it is not easy to disperse, and there is a phenomenon of layered accumulation. It is beneficial to reduce the modulus and affect the electro-induced deformation of the material. It has been proved by experiments that the electro-induced deformation of the elastomer composite material at 2kV / mm does not exceed 1%.

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