Materials comprising reduced graphene oxide, devices comprising such materials and methods of making such materials

Abstract

The present invention relates to materials comprising reduced graphene oxide, wherein the degree of reduction of the graphene oxide exhibits a spatial variation such that the material exhibits a gradient in conductivity and / or permittivity. The material may eg be used in electrical devices for field grading and / or charge dissipation purposes. Examples of electrical devices in which the material is beneficial include cable accessories, bushings, power cables, microelectronics, switchgear, and the like. The invention further relates to a method of manufacturing a material for electrical applications. The method involves treating different parts of the graphene oxide element differently to achieve different degrees of reduction of the graphene oxide within the element, resulting in a sample with a gradient in conductivity and / or permittivity. The material can be obtained, for example, by applying a thermal gradient to the graphene oxide element, or by irradiation of the graphene oxide element.

Description

Technical field

[0001] The present invention relates to the field of graphene oxide-based materials and electrical devices using graphene oxide-based materials. Background technique

[0002] In many applications of electrical technology, materials with different electrical properties are combined. The electric field distribution in and around an electrical device depends on the electrical characteristics of the materials used in the device, as well as the geometry of the device. In AC applications, the field distribution depends to a large extent on the dielectric constant of the device material, while in DC applications, the field distribution largely depends on the electrical conductivity of the device material.

[0003] In many devices, different materials that exhibit very different electrical / dielectric properties are in contact. In such a device, the equipotential lines of the electric field tend to concentrate on the interface towards the low dielectric constant or low con...

Examples

Embodiment Construction

[0047] Graphene oxide (GO) is a layered carbon graphite with a single layer or several layers, which has sufficient functional groups such as epoxy, hydroxyl, and carboxyl functional groups. The ideal chemical structure of GO is shown in figure 1 in.

[0048] Graphene oxide has attracted more interest in recent years because the material is an intermediate product when graphene is manufactured from graphite. In ideal graphene, a single-atom-thick planar variant of carbon, sp 2 -The hybrid carbon atoms are arranged in a honeycomb lattice that exhibits high electrical conductivity. In contrast, the abundance of functional groups in GO partially destroys the sp in the lattice 2 -Hybrid, GO partially includes the sp of the tetrahedral bond 3 carbon atom. Therefore GO is insulating, and as a synthetic GO film usually exhibits 10 12 Ωsq -1 Or higher room temperature sheet resistance.

[0049] There are various methods for reducing GO to enhance its chemical affinity with graphene. A r...

Technical field

[0001] The present invention relates to the field of graphene oxide-based materials and electrical devices using graphene oxide-based materials. Background technique

[0002] In many applications of electrical technology, materials with different electrical properties are combined. The electric field distribution in and around an electrical device depends on the electrical characteristics of the materials used in the device, as well as the geometry of the device. In AC applications, the field distribution depends to a large extent on the dielectric constant of the device material, while in DC applications, the field distribution largely depends on the electrical conductivity of the device material.

[0003] In many devices, different materials that exhibit very different electrical / dielectric properties are in contact. In such a device, the equipotential lines of the electric field tend to concentrate on the interface towards the low dielectric constant or low con...

Examples

Embodiment Construction

[0047] Graphene oxide (GO) is a layered carbon graphite with a single layer or several layers, which has sufficient functional groups such as epoxy, hydroxyl, and carboxyl functional groups. The ideal chemical structure of GO is shown in figure 1 in.

[0048] Graphene oxide has attracted more interest in recent years because the material is an intermediate product when graphene is manufactured from graphite. In ideal graphene, a single-atom-thick planar variant of carbon, sp 2 -The hybrid carbon atoms are arranged in a honeycomb lattice that exhibits high electrical conductivity. In contrast, the abundance of functional groups in GO partially destroys the sp in the lattice 2 -Hybrid, GO partially includes the sp of the tetrahedral bond 3 carbon atom. Therefore GO is insulating, and as a synthetic GO film usually exhibits 10 12 Ωsq -1 Or higher room temperature sheet resistance.

[0049] There are various methods for reducing GO to enhance its chemical affinity with graphene. A r...

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