Graphite exfoliated graphene nanoplatelets and method of use to prepare ptfc composites

Abstract

The application discloses a method for preparing PTFE composite material by using graphite exfoliated graphene nanosheets, which comprises the following steps: S1, adding raw materials into a container, wherein the raw materials comprise graphite and a first oil-water exfoliating solution; S2, sealing the container with the mixed raw materials, and vibrating and shaking the container for 5 minutes at room temperature to obtain exfoliated graphene nanosheets. The method for exfoliating graphene nanosheets is used to prepare graphene PTFE nanocomposite material, and the specific steps comprise the following: A1, adding composite material preparation materials into a container, wherein the composite material preparation materials comprise graphite, PTFE powder and a second oil-water exfoliating solution; A2, sealing the container with the mixed composite material preparation materials, and vibrating and shaking the container for 5 minutes. The graphite is used to realize the exfoliation of graphite to obtain graphene nanosheets by adding the first oil-water exfoliating solution, the whole process is simple in procedure and low in material cost, and the macroscopic 'climbing' process of the graphite in situ unfolding into graphene nanosheets can be clearly observed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of graphene nanosheet preparation and application, and particularly relates to a method for preparing PTFE composite material by exfoliating graphene nanosheet from graphite. BACKGROUND

[0002] Polytetrafluoroethylene (PTFE) is a high-performance synthetic polymer, which is known for its excellent chemical resistance, heat resistance, low temperature resistance and low friction characteristics, and is known as the "King of Plastics". PTFE is a perfluorinated linear polymer, which is a highly symmetrical non-polar polymer compound. The structure of PTFE is a linear macromolecular structure, and the molecular chain is in a helical conformation.

[0003] Since graphene nanosheet was successfully prepared in 2004, it has attracted much attention in the past decade due to its unique and fascinating properties, which has also triggered a research boom in two-dimensional nanomaterials. The two-dimensional structure with a single atomic layer thickness endows graphene nanosheet with extraordinary optical, electronic, magnetic and mechanical properties, making graphene nanosheet exhibit great application potential in many fields such as biology, medicine, chemistry, physics and environmental science.

[0004] However, the chemically stable graphene nanosheet with complete structure has weak interaction with other media, and there is a strong van der Waals force between the layers, which makes it difficult to disperse in common solvents to form stable solutions. PTFE is difficult to melt process. When the existing technology uses graphene nanosheet to modify PTFE, it is difficult to form uniform and stable dispersion in the polymer, resulting in uneven distribution of graphene nanosheet in the prepared graphene PTFE nanocomposite, and unstable properties of the graphene PTFE nanocomposite, which greatly hinders the further research and application of graphene nanosheet. SUMMARY

[0005] In view of the above deficiencies of the prior art, the present application provides a method for exfoliating graphene nanosheet from graphite and stably transferring it to the surface of PTFE powder at a nanoscale, which is low in cost and simple in process.

[0006] To achieve the above-mentioned application purposes, the technical scheme adopted by the present application is as follows:

[0007] A method for exfoliating graphene nanosheet from graphite is provided, which comprises the following steps:

[0008] S1: adding raw materials into a container, wherein the raw materials comprise graphite and a first oil-water stripping liquid;

[0009] S2: sealing the container containing the raw materials, and vibrating and shaking the container at room temperature for 5 minutes to obtain exfoliated graphene nanosheet.

[0010] Further, 4ml of the first oil-water stripping liquid is added to every 8mg of graphite.

[0011] Further, the first oil-water stripping liquid comprises aviation kerosene and water, and the ratio of aviation kerosene to water is 1:2-1:5.

[0012] Further, the specific steps of adding the first oil-water stripping liquid to the container include:

[0013] S11: Weigh the graphite and put it into the container;

[0014] S12: Add aviation kerosene to the container, mix the graphite and aviation kerosene by shaking, and make the graphite fully dispersed in the aviation kerosene;

[0015] S13: After the graphite is fully dispersed in the aviation kerosene, add water and perform step S2.

[0016] Further, the graphite is graphite powder, and the graphite powder is a powder product with a mesh number of 3000-12000.

[0017] Further, the graphite powder is a powder product with a mesh number of 10000.

[0018] A method for preparing a graphene PTFE nanocomposite by using graphite to strip graphene nanosheets, the PTFE composite is a graphene PTFE nanocomposite, and the specific steps include the following:

[0019] A1: Fluorine treatment is performed on the inner wall of the container to form a fluorine-containing film on the inner wall of the container;

[0020] A2: Add graphite and aviation kerosene to the container, and mix the graphite and aviation kerosene by shaking;

[0021] A3: After the graphite is fully dispersed in the aviation kerosene, add water and shake for 5 minutes at room temperature;

[0022] A4: Add PTFE powder to the container, and the mass ratio of PTFE powder to aviation kerosene is 100:19-100:22, and shake for 5 minutes to obtain a graphene PTFE nanocomposite.

[0023] Further, the ratio of aviation kerosene to water is 1:5.

[0024] Further, the aviation kerosene and water are the second oil-water stripping liquid, and 12g of PTFE powder and 15mg-150mg of graphite are added to every 18ml of the second oil-water stripping liquid.

[0025] Further, the specific steps of step A1 include: adding the fluorine-containing coating into a container, shaking to make the inner wall of the container fully wetted by the fluorine-containing coating; then pouring out the excess fluorine-containing coating, and drying the container.

[0026] The beneficial effects of the present application are:

[0027] The present application uses graphite to achieve the exfoliation of graphite to obtain graphene nanosheets by adding a first oil-water stripping liquid. The whole process is simple in procedure and low in material cost. In a laboratory environment, the macroscopic "climbing" process of the in-situ unfolding of graphite into graphene nanosheets can be clearly observed, which can help the research on the dispersion of graphene nanosheets. One of the key points of the technology is to maintain the ratio of PTFE and aviation kerosene between 100 and 19 to 22 in the four-component Pickering emulsion system composed of three lipophilic components and two solids and two liquids. In the four-component Pickering system, the oil phase must be aviation kerosene.

[0028] By using a second oil-water stripping liquid and adding PTFE powder, the adhesion of graphene nanosheets to PTFE can be achieved, and the graphene nanosheets are uniformly attached to the surface of PTFE, which can prepare graphene PTFE nanocomposites with stable performance, and provide inspiration and help for the research and application of graphene nanosheets in polymer modification. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a flowchart of Example 1;

[0030] Figure 2 It is an example diagram of Example 1;

[0031] Figure 3 It is a flowchart of Example 2;

[0032] Figure 4 It is an example diagram of Example 2. DETAILED DESCRIPTION

[0033] The specific embodiments of the present application are described below to facilitate the understanding of the present application by those skilled in the art, but it should be clear that the present application is not limited to the scope of the specific embodiments. It is obvious to those skilled in the art that various changes are within the spirit and scope of the present application as defined in the appended claims, and all applications utilizing the concept of the present application are within the scope of protection.

[0034] Example 1

[0035] As Figure 1 shown, a method for exfoliating graphene nanosheets from graphite includes the following steps:

[0036] S1: adding raw materials into the container, the raw materials including graphite and the first oil-water stripping liquid;

[0037] The specific steps of adding the first oil-water stripping liquid into the container include:

[0038] S11: weighing the graphite and putting it into the container;

[0039] S12: adding the aviation kerosene into the container, mixing the graphite and the aviation kerosene by shaking, and making the graphite fully dispersed in the aviation kerosene;

[0040] S13: after the graphite is fully dispersed in the aviation kerosene, adding water, and executing the step S2.

[0041] S2: closing the container with the mixed raw materials, and shaking for 5 minutes at room temperature to obtain the stripped graphene nanosheets as shown in Figure 2 .

[0042] 4ml of the first oil-water stripping liquid is added for every 8mg of the graphite.

[0043] The first oil-water stripping liquid includes the aviation kerosene and water, and the ratio of the aviation kerosene to water is 1:2. In other embodiments of the present application, the ratio of the aviation kerosene to water can also be 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5 or 1:5.

[0044] In specific implementation, the ratio of the aviation kerosene to water in the first oil-water stripping liquid is 1:3, which is the most preferred.

[0045] The graphite is graphite powder, and the graphite powder adopts a powder product with a mesh number of 3000. In other embodiments of the present application, the graphite powder can also adopt a powder product with a mesh number of 5000, 7000, 10000 or 12000.

[0046] In specific implementation, the graphite powder adopts a powder product with a mesh number of 12000, which is the most preferred.

[0047] Embodiment 2

[0048] As shown in Figure 3 , a method for preparing a graphene PTFE nanocomposite by using a graphite to strip graphene nanosheets, the PTFE composite being a graphene PTFE nanocomposite, and the specific steps include the following:

[0049] A1: performing fluorine coating treatment on the inner wall of the container to form a fluorine-containing film on the inner wall of the container;

[0050] The specific steps include: adding the fluorine-containing coating into the container, wetting the inner wall of the container with the fluorine-containing coating by shaking, then pouring out the excess fluorine-containing coating, and drying the container.

[0051] A2: adding graphite and aviation kerosene into a container, and mixing the graphite and aviation kerosene by shaking;

[0052] A3: after the graphite is fully dispersed in the aviation kerosene, water is added, and the container is shaken for 5 minutes at room temperature;

[0053] A4: PTFE powder is added into the container, the mass ratio of the PTFE powder to the aviation kerosene is 100:19-100:22, and the container is shaken for 5 minutes to obtain a graphene-PTFE nanocomposite. In a specific implementation, the PTFE powder is PTFE powder after aging treatment.

[0054] The second oil-water separation liquid includes aviation kerosene and water, and the ratio of the aviation kerosene to the water is 1:5.

[0055] 12 g of PTFE powder and 15 mg of graphite are added into 18 ml of the second oil-water separation liquid. In other embodiments of the present application, the amount of graphite in 18 ml of the second oil-water separation liquid can also be 30 mg, 60 mg, 105 mg, or 150 mg. As shown in FIG. 2, from left to right, the graphene-PTFE nanocomposites prepared by using 15 mg, 30 mg, 60 mg, 105 mg, and 150 mg of graphite, respectively, are shown. Figure 4 Figure 4 As shown in FIG. 3, the graphene nanosheets are uniformly attached to the PTFE.​

Claims

1. A method of exfoliating graphene nanoplatelets from graphite, characterized by, The method comprises the following steps: S1: adding raw materials into a container, wherein the raw materials comprise graphite and a first oil-water stripping liquid; S2: sealing the container with the raw materials mixed therein, and vibrating and shaking for 5 minutes at room temperature to obtain stripped graphene nanosheets; 4 ml of the first oil-water stripping liquid is added to every 8 mg of graphite; The first oil-water stripping liquid comprises aviation kerosene and water, and the ratio of aviation kerosene to water is 1:2-1:5; The specific steps of adding the first oil-water stripping liquid into the container comprise: S11: weighing the graphite and placing it into the container; S12: adding aviation kerosene into the container, and mixing the graphite and the aviation kerosene by vibrating and shaking; and making the graphite fully dispersed in the aviation kerosene; S13: after the graphite is fully dispersed in the aviation kerosene, water is added, and the step S2 is performed.

2. The method of exfoliating graphene nanosheets from graphite according to claim 1, wherein, The graphite is graphite powder, and the graphite powder is a powder product with a mesh number of 3000-12000.

3. The method of exfoliating graphene nanosheets from graphite according to claim 2, wherein, The graphite powder is a powder product with a mesh number of 10000-12000.

4. A method for preparing a PTFE composite material using the method according to any one of claims 1 to 3, characterized in that, The PTFE composite material is a graphene PTFE nanocomposite material, and the specific preparation steps thereof comprise the following: A1: performing fluorine treatment on the inner wall of the container to form a fluorine-containing film on the inner wall of the container; A2: adding graphite and aviation kerosene into the container, and mixing the graphite and the aviation kerosene by vibrating and shaking; A3: after the graphite is fully dispersed in the aviation kerosene, water is added, and vibrating and shaking is performed for 5 minutes at room temperature; A4: adding PTFE powder into the container, and the mass ratio of the PTFE powder to the aviation kerosene is 100:19-100:22, and vibrating and shaking is performed for 5 minutes to obtain the graphene PTFE nanocomposite material; The ratio of the aviation kerosene to water is 1:5; The aviation kerosene and water are a second oil-water stripping liquid, and 12 g of PTFE powder and 15 mg-150 mg of graphite are added to every 18 ml of the second oil-water stripping liquid.

5. The method of making a PTFE composite material of claim 4, wherein, The specific steps of the step A1 comprise: adding fluorine-containing paint into the container, and making the inner wall of the container fully wetted by the fluorine-containing paint by shaking; then, the excess fluorine-containing paint is poured out, and the container is dried.

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