Graphene-coated intelligent fabric for electromagnetic shielding and preparation method thereof

Abstract

The invention provides a graphene-coated intelligent fabric for electromagnetic shielding and a preparation method of the graphene-coated intelligent fabric. Graphene is attached to a fabric substrate in a physical friction manner and uniformly covers the fabric substrate in a layer-by-layer stacked microstructure. By changing the number of coating layers of the graphene and the substrate of the fabric, the intelligent fabric uniformly covered by the graphene with different conductivities is obtained, and good electromagnetic shielding capability is achieved. The graphene intelligent fabric for electromagnetic shielding is prepared in a physical friction mode, solvent and ink technologies are not depended on, the preparation mode is simple and low in cost, and large-scale production is easy to achieve.

Description

Technical Field

[0001] The present invention belongs to the field of electromagnetic shielding, and particularly relates to a graphene-coated electromagnetic shielding intelligent fabric and a preparation method thereof. Background Art

[0002] Graphene has many excellent properties, such as mechanical, thermal, electrical, magnetic, and optical properties. Graphene has extremely high strength and elastic modulus, and good high-temperature stability and thermal conductivity have practical application values. In addition, at room temperature, the resistivity of graphene is only 10 -6 Ω·cm, and the maximum carrier mobility is as high as 250000 cm 2 V -2 s -2 , which is slightly lower than that of metallic silver, has excellent electrical conductivity, and has attracted much attention in the field of electromagnetic shielding. Fabric-based electromagnetic shielding materials have both electromagnetic shielding functions and the properties of the fabric substrate such as softness, breathability, deformability, and skin-fitting, which more meet the requirements of intelligent wearable electromagnetic shielding materials. However, most traditional fabric substrates are insulating or dielectric substances and almost do not have electromagnetic properties. Therefore, the key to preparing fabric-based electromagnetic shielding materials lies in endowing and improving the conductive or magnetic properties of fibers or fabrics. That is, by macroscopically assembling common electromagnetic shielding functional materials according to functional orientation and textile fibers, functional textiles or electromagnetic shielding intelligent fabrics with flexibility, wearability, conductivity, and electromagnetic shielding can be obtained.

[0003] The existing methods for electromagnetic shielding intelligent fabrics are basically to add two-dimensional functional materials (such as graphene, MXene, MoS2, black phosphorus, BN) to the polymer matrix through melting or blending processes during the fiber spinning process to directly obtain fibers with conductive / magnetic functions, and then weave them into fabrics; for the formed fabric substrates, methods such as functional filler coating (dipping, spraying, scraping, etc.) or metal plating are usually used to assemble adjacent flakes into a continuous film through van der Waals force interaction. However, these technical formulations rely on the assistance of binders and solutions, which limits their production and causes waste. Therefore, it is very important to develop an industrially producible electromagnetic shielding graphene-coated intelligent fabric with low cost and large stress change. Summary of the Invention

[0004] The purpose of the present invention is to provide a graphene-coated intelligent fabric for electromagnetic shielding and a preparation method thereof, to achieve good electromagnetic shielding ability, and the preparation method is simple.

[0005] According to the first aspect of the present invention, the following technical solutions are adopted by the present invention: A graphene-coated intelligent fabric for electromagnetic shielding, characterized in that the intelligent fabric has a double-layer structure, including from the inside out: a fabric substrate, a graphene outer shell layer; the graphene outer shell layer is formed by physically rubbing and attaching graphene nanosheets on the fabric substrate with the help of a carrier; by changing the number of layers of graphene nanosheets and the conductivity of the intelligent fabric, good electromagnetic shielding ability is achieved.

[0006] Preferably, the diameter of the constituent fibers of the fabric substrate is 4-100 microns; the fiber shape of the fabric substrate includes solid fibers and hollow fibers.

[0007] Preferably, the fabric is a natural fiber (such as cotton, linen, wool, silk, etc.) fabric or a chemical fiber (such as polyester, nylon, acrylic, vinylon, spandex, acetate fiber, etc.) fabric or a mixed fabric of natural fiber and chemical fiber.

[0008] Preferably, the number of layers of the graphene nanosheets is 1-20 layers, and the sheet diameter of the graphene nanosheets is 1-20 microns.

[0009] Preferably, the graphene nanosheets are coated on the surface and inside of the fabric substrate with the help of a carrier.

[0010] Preferably, the carrier is a polymer film.

[0011] Preferably, the material of the carrier includes nitrile rubber, polytetrafluoroethylene, polyethylene, and polypropylene.

[0012] According to the second aspect of the present invention, the following technical solutions are adopted in the present invention: A preparation method of a graphene-coated intelligent fabric, characterized by including the following steps: (1) Using a polymer film as a carrier, the polymer carrier and graphene nanosheets are fully contacted by physical friction to realize the in-situ loading of graphene nanosheets on the surface of the polymer carrier film; (2) Under pressure conditions, the graphene nanosheets and the fabric substrate are subjected to multiple dragging-adhesion-separation processes by using the polymer carrier film, so that the graphene nanosheets can interact with the fabric surface through van der Waals forces to form a graphene outer shell layer on the surface of the fabric substrate.

[0013] Preferably, nitrile rubber (NBR) is used as the polymer film.

[0014] The present invention can obtain intelligent fabrics with different conductivities and uniformly covered with graphene by changing the coating layer number of graphene and the fabric substrate, and achieve good electromagnetic shielding ability. The present invention adopts a physical friction method to prepare a graphene intelligent fabric for electromagnetic shielding, which does not rely on solvent and ink technologies, has a simple preparation method and low cost, and is easy to realize large-scale production. Description of the Drawings

[0015] Figure 1 Scanning electron microscope image of a graphene nanoplatelet-coated smart fabric provided for an example of the present invention.

[0016] Figure 2 Electromagnetic shielding performance diagram of a graphene nanoplatelet-coated smart fabric provided for an example of the present invention. Detailed implementation manners

[0017] The preparation method of the graphene-coated smart fabric for electromagnetic shielding of the present invention includes the following steps: (1) Adhere graphene nanoplatelets to a polymer carrier membrane: Use nitrile rubber (NBR) as the polymer carrier membrane. Under the horizontal force of carriers by dragging the polymer, the graphene nanoplatelets are transferred from the carrier and adhered to the polytetrafluoroethylene substrate.

[0018] (2) Separate the polymer carrier membrane from the polytetrafluoroethylene substrate by a drag-adhesion-separation process. By repeating this process, the graphene nanoplatelets adhere to the polytetrafluoroethylene substrate and the graphene nanoplatelets form a graphene film through vdW interactions.

[0019] In the present invention, unless otherwise specified, the materials used are all conventional commercially available products in the art.

[0020] In the present invention, the graphene-coated smart fabric provided in the example aspect has a bilayer structure, including a fabric substrate and a graphene part. The fabric substrate can be divided into solid fibers and hollow fibers.

[0021] In the present invention, the graphene layer is formed by attaching graphene powder to the fabric substrate in a physical friction manner. The graphene layer can be present on the surface or inside of the fabric substrate. The process of preparing graphene fibers involves: graphene powder, fabric substrate, and polymer carrier.

[0022] In the present invention, the unit loading of graphene powder on the fabric substrate is 0.5 mg / m. The thickness of the graphene powder sheet layer is 5 - 8 layers, and the sheet layer diameter is 3 - 8 microns. By placing the graphene on the nitrile rubber film, the graphene can be transferred onto the fabric substrate through physical friction.

[0023] In the present invention, a fabric substrate made of natural fibers such as cotton, hemp, wool, and silk, and chemical fibers such as polyester, nylon, acrylic, vinylon, spandex, and acetate fiber is selected, and the fiber diameter is 0.8 mm.

[0024] In the present invention, a polyethylene film is selected as the carrier of the graphene powder.

[0025] In the present invention, the graphene powder has a sheet layer thickness of 3-5 layers and a sheet diameter of 3-5 microns. The graphene powder is placed on a polyethylene film, and the graphene is transferred onto a fabric substrate by physical friction.

[0026] In the present invention, the prepared graphene-coated intelligent fabric substrate is elastic and can be used for applications such as electromagnetic shielding and electromagnetic protection. The S parameters of the graphene nanosheet-coated intelligent fabric are tested in a vector network analyzer, and its electromagnetic shielding performance in the 8-12 GHz frequency band is calculated. Among them, the reflection absorption efficiency is ~19 dB, the absorption shielding efficiency is ~40 dB, the total shielding efficiency is ~59 dB, and the shielding efficiency exceeds 99.9999%. Figure 1 The scanning electron microscope image of the graphene nanosheet-coated intelligent fabric prepared in the present invention is shown. Figure 2 The electromagnetic shielding performance of the graphene nanosheet-coated intelligent fabric prepared in the present invention is shown.

Claims

1. A graphene-coated intelligent fabric for electromagnetic shielding, characterized in that, The intelligent fabric has a double-layer structure, which includes, from the inside out: a fabric substrate and a graphene outer shell layer; the graphene outer shell layer is formed by physically rubbing and attaching graphene nanosheets to the fabric substrate with the aid of a carrier; by changing the number of layers of graphene nanosheets and the conductivity of the intelligent fabric, good electromagnetic shielding ability is achieved.

2. The graphene-coated smart fabric according to claim 1, wherein The constituent fibers of the fabric substrate have a diameter of 4-100 microns; the fiber shapes of the fabric substrate include solid fibers and hollow fibers.

3. The graphene-coated smart fabric according to claim 1, wherein The fabric is a natural fiber fabric, a chemical fiber fabric, or a mixed fabric of natural fibers and chemical fibers.

4. The graphene-coated smart fabric according to claim 1, wherein The number of layers of the graphene nanosheets is 1-20 layers, and the sheet diameter of the graphene nanosheets is 1-20 microns.

5. The graphene-coated smart fabric according to claim 1, wherein, The graphene nanosheets are coated on the surface and inside of the fabric substrate with the aid of a carrier.

6. The graphene-coated intelligent fabric according to claim 1, wherein The carrier is a polymer film.

7. The graphene-coated intelligent fabric according to claim 6, characterized in that, The material of the carrier includes nitrile rubber, polytetrafluoroethylene, polyethylene, and polypropylene.

8. The preparation method of the graphene-coated intelligent fabric according to claim 1, wherein It includes the following steps: (1) Using a polymer film as a carrier, the polymer carrier and graphene nanosheets are brought into full contact by physical friction to achieve in-situ loading of graphene nanosheets on the surface of the polymer carrier film; (2) Under pressure conditions, the polymer carrier film is used to perform multiple drag-adhesion-separation processes on the graphene nanosheets and the fabric substrate, so that the graphene nanosheets can interact with the fabric surface through van der Waals forces to form a graphene outer shell layer on the surface of the fabric substrate.

9. The preparation method according to claim 8, characterized in that Nitrile rubber (NBR) is used as the polymer film.

Images