A fluorine-modified graphene material and its preparation method and application

Abstract

The present invention relates to a fluorine-modified graphene material and its preparation method and application. The specific preparation method is as follows: graphene, a carbon source, a surfactant, and water are mixed and stirred in a certain mass ratio to obtain a mixed solution; the mixed solution is transferred to a closed reaction chamber and heated and kept warm for a period of time; the mixed solution is cooled, solid-liquid separation is performed to obtain a solid phase, the obtained solid phase is dried, and after drying, it is crushed to obtain powder A; a fluorine treatment agent is deposited on the surface of powder A by chemical vapor deposition to obtain fluorine-modified graphene. A film prepared by mixing the fluorine-modified graphene of the present invention with a polyimide solution has electrical insulation properties, and its thermal conductivity is much higher than that of the polyimide film.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon materials, and in particular to a fluorine-modified graphene material and a preparation method and application thereof. Background Art

[0002] The rapid development of portable devices has placed higher demands on the high power and high integration of electronic devices. To reduce the negative impact of high power and high integration on the overall performance and reliability of electronic devices, electronic device packaging materials are required to have both excellent insulation and thermal conductivity.

[0003] Graphene is currently the most typical two-dimensional free-state atomic crystal and the basic building block for zero-dimensional quantum dots, one-dimensional carbon nanotubes, and three-dimensional graphite. In 2004, the Geim group in the UK first reported single-atomic-layer graphene in Science. Graphene has a very high thermal conductivity, with a theoretical value of 5300 W / (m·K), but its excellent electrical conductivity limits its application in electronic products. Fluorinated graphene is a key member of the fluorinated carbon material family. Because fluorine atoms have low polarizability, the strongest electronegativity, and a small van der Waals radius, the combination of fluorine and perfluorinated groups with graphene imparts high thermal conductivity and excellent electrical insulation properties. Therefore, fluorinated graphene can be used in electronic packaging materials, high-temperature thermal conductive coatings, and corrosion-resistant coatings.

[0004] Graphene is chemically inert and it is difficult to graft functional groups onto graphene. The original method for preparing fluorinated graphene is to directly perform gas phase fluorination on graphene using fluorinating agents such as F2 and XeF2. Chinese patent CN111825073A discloses a method for preparing fluorinated graphene, which uses F2 for fluorination modification. Due to the high price of fluorinating agents, difficulty in operation, and large safety hazards, many improved methods have emerged in recent years, such as photochemical fluorination, hydrothermal fluorination, and plasma fluorination. Chinese patent CN102530911B discloses a method for preparing fluorinated graphene, which uses hydrazine hydrate to reduce graphene oxide prepared by the Hummers method, and reacts with a fluorine treatment agent (such as 1,1,2,3,3,3-hexafluoropropyldiethylamine) under an inert atmosphere to obtain fluorinated graphene, but the graphene used is graphene oxide, which is costly. Therefore, it is very necessary and of great significance to use a high-safety, low-cost method to fluorine-modify graphene. Summary of the Invention

[0005] To address the above technical issues, the present invention provides a fluorine-modified graphene material and a method for preparing the same. The method hydrothermally deposits carbon nanoparticles with active groups onto graphene, and then grafts a fluorine treatment agent onto the carbon nanoparticles with active groups using vapor-phase modification to obtain the fluorine-modified graphene.

[0006] The first object of the present invention is to provide a method for preparing a fluorine-modified graphene material, comprising the following steps:

[0007] Mixing graphene, a carbon source, a surfactant, and water in a certain mass ratio and stirring to obtain a mixed solution;

[0008] The mixed solution is transferred into a sealed reaction chamber and heated for a period of time; cooled, solid-liquid separation is performed to obtain a solid phase, the obtained solid phase is dried, and then pulverized to obtain powder A;

[0009] A fluorine treatment agent is deposited on the surface of powder A by using a chemical vapor deposition method to obtain fluorine-modified graphene.

[0010] In one embodiment of the present invention, the carbon source is selected from one or more of citric acid, sodium citrate, cyclodextrin, lactose, fructose, glucose, sucrose, maltose, and starch.

[0011] In one embodiment of the present invention, the graphene is liquid-phase exfoliated graphene powder, with a surface functional group content of less than 0.1 wt%, a thickness of 0.35 to 2 nm, and a particle size of 1 to 20 μm.

[0012] In one embodiment of the present invention, the surfactant is selected from one or more of sodium dodecylbenzenesulfonate, sodium lauryl sulfate, and sodium lauryl polyoxyethylene ether sulfate.

[0013] In one embodiment of the present invention, the mass ratio of the graphene, carbon source, surfactant and water is 1-4:16:0.1:80.

[0014] In one embodiment of the present invention, the reaction temperature in the closed reaction chamber is 60-180° C., and the holding time is 1-24 hours.

[0015] In one embodiment of the present invention, the drying temperature is 60-100° C., and the water content of the powder A is 1-8 wt %.

[0016] In one embodiment of the present invention, the fluorine treatment agent is one or more of terminal hydroxyl fluorinated polysiloxane, terminal hydroxypropyl fluorinated polysiloxane, perfluorooctyltrimethoxysilane, perfluorooctyltriethoxysilane, 3,3,3,-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3,3,3-trifluoropropylmethyldimethoxysilane, heptadecafluorodecyltrimethoxysilane, and heptadecafluorodecyltriethoxysilane.

[0017] The second object of the present invention is to provide a fluorine-modified graphene material obtained by the preparation method.

[0018] The third object of the present invention is to provide the use of the fluorine-modified graphene material in the preparation of polyimide films.

[0019] The above technical solution of the present invention has the following advantages over the prior art:

[0020] Graphene is chemically inert and difficult to graft functional groups.

[0021] First, the present invention uses an indirect method to treat graphene, avoiding the use of toxic fluorine gas to treat graphene and expensive graphene oxide.

[0022] Second, the present invention adopts a vapor deposition method to avoid the wastewater problem caused by wet treatment.

[0023] Third, the present invention adopts an atomization method to solve the problem of gas phase modification of some non-volatile fluorine treatment agents.

[0024] Fourth, a film prepared by mixing the fluorine-modified graphene of the present invention with a polyimide solution has electrical insulation properties, and its thermal conductivity is much higher than that of the polyimide film. The present invention provides a method for preparing a fluorine-modified graphene material, comprising: S1, mixing and stirring graphene, a carbon source, a surfactant, and water in a certain mass ratio; S2, transferring the solution of step S1 to a sealed container and heating and keeping it warm for a period of time; S3, after the solution of step S2 is cooled to room temperature, filtering it, placing it in a vacuum box and drying it to obtain powder A; S4, depositing a fluorine treatment agent on powder A using a chemical vapor deposition method to obtain fluorine-modified graphene. The fluorine-modified graphene material provided by the present invention is obtained by hydrothermally depositing carbon nanoparticles with active groups on graphene, and then grafting the fluorine treatment agent onto the carbon nanoparticles with active groups to obtain fluorine-modified graphene. This makes the modified graphene an insulator and has high thermal conductivity, providing an effective method for promoting the industrial application of graphene. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0026] Figure 1 Schematic diagram of the graphene gas phase treatment process of the present invention.

[0027] Figure 2 This is the TEM image of graphene in Example 1 of the present invention.

[0028] Figure 3 This is a TEM image of pretreated powder A in Example 1 of the present invention. DETAILED DESCRIPTION

[0029] In order to solve the technical problems pointed out in the background technology, the present invention provides a fluorine-modified graphene material and its preparation method and application, which are specifically achieved through the following scheme:

[0030] The present invention provides a method for preparing a fluorine-modified graphene material, comprising the following steps:

[0031] Mixing graphene, a carbon source, a surfactant, and water in a certain mass ratio and stirring to obtain a mixed solution;

[0032] The mixed solution is transferred into a sealed reaction chamber and heated for a period of time; cooled, solid-liquid separation is performed to obtain a solid phase, the obtained solid phase is dried, and then pulverized to obtain powder A;

[0033] A fluorine treatment agent is deposited on the surface of powder A by using a chemical vapor deposition method to obtain fluorine-modified graphene.

[0034] In a specific embodiment, the carbon source is selected from one or more of citric acid, sodium citrate, cyclodextrin, lactose, fructose, glucose, sucrose, maltose, and starch. Preferably, one or more of citric acid, sodium citrate, glucose, and sucrose are used in combination; more preferably, glucose and sucrose are used.

[0035] In a specific embodiment, the graphene is liquid-phase exfoliated graphene powder, with a surface functional group content of less than 0.1 wt%, a thickness of 0.35 to 2 nm, and a particle size of 1 to 20 μm.

[0036] Furthermore, preferably, the surface functional group content is less than 0.1 wt%, the thickness is 0.35 to 2 nm, and the particle size is 6 to 20 μm; more preferably, the surface functional group content is less than 0.1 wt%, the thickness is 0.35 to 2 nm, and the particle size is 10 to 15 μm.

[0037] In a specific embodiment, the surfactant is selected from one or more of sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, and sodium lauryl polyoxyethylene ether sulfate; preferably sodium dodecylbenzenesulfonate and sodium dodecyl sulfate; more preferably sodium dodecyl sulfate.

[0038] In one embodiment of the present invention, the mass ratio of the graphene, carbon source, surfactant, and water is (1-4):(8-32):0.1:80, preferably (2-4):(12-20):0.1:80, and more preferably (2-4):(14-17):0.1:80.

[0039] According to the present invention, the specific steps for preparing the mixed solution are: first dissolving the surfactant in water, then adding the carbon source, stirring to dissolve, and finally adding the graphene, stirring to disperse evenly. The present invention does not limit the stirring device, stirring time, and stirring speed, which are all known to those skilled in the art.

[0040] In a specific embodiment, the reaction temperature in the sealed reaction chamber is 60-200°C, and the holding time is 1-24 hours. The present invention does not limit the device of the sealed reaction chamber, and those skilled in the art are familiar with it, and it can be a hydrothermal reactor. The heating and holding temperature is 60-200°C, and the holding time is 1-24 hours; preferably, the temperature is 80-180°C, and the holding time is preferably 6-20 hours; more preferably, the temperature is 120-160°C, and the holding time is more preferably 8-12 hours.

[0041] In a specific embodiment, the drying temperature is 60-100°C. The drying apparatus described in the present invention is not limited, and preferably a drying oven is used. The present invention does not limit the type of drying oven, and any drying oven known to those skilled in the art can be used. The drying temperature is 60-100°C, preferably 80-100°C, and more preferably 80-90°C.

[0042] In a specific embodiment, the water content of the powder A is 1 to 8 wt %, preferably 2 to 6 wt %, and more preferably 3 to 5%.

[0043] In a specific embodiment, the fluorine treatment agent is one or more of hydroxyl-terminated fluorine-containing polysiloxane, hydroxypropyl-terminated fluorine-containing polysiloxane, perfluorooctyltrimethoxysilane, perfluorooctyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3,3,3-trifluoropropylmethyldimethoxysilane, heptadecafluorodecyltrimethoxysilane, and heptadecafluorodecyltriethoxysilane. Preferably, the fluorine treatment agent is one or more of perfluorooctyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, and 3,3,3-trifluoropropyltrimethoxysilane; more preferably, perfluorooctyltrimethoxysilane and heptadecafluorodecyltrimethoxysilane.

[0044] In the specific embodiment, the present invention does not limit the chemical vapor deposition device, which is well known to those skilled in the art. According to the present invention, the specific steps of the chemical vapor deposition are: using Figure 1 In this method, the fluorine treatment agent and ammonia water are placed in two beakers respectively, and powder A is placed on top of the fluorine treatment agent. An ultrasonic atomizer is placed in the beaker containing the fluorine treatment agent, and the atomization time and interval are set. Then, the atomization is turned on and vacuum is applied. The vacuum is continued for a period of time, and the treated powder A is placed in an oven to dry for a period of time to obtain fluorine-modified graphene.

[0045] In a specific embodiment, the present invention does not limit the mass ratio of powder A to fluorine treatment agent, and the present invention does not limit the concentration and mass of ammonia water, which is preferably 1 to 10 wt %; more preferably 5 to 10 wt %.

[0046] In a specific embodiment, the present invention does not limit the atomization method and atomization time, but ultrasonic atomization is preferred, and the atomization frequency is preferably 1.7 MHz; the atomization time is preferably 30 to 600 s; more preferably 60 to 360 s.

[0047] In a specific embodiment, the present invention does not limit the vacuuming time, and the vacuuming time is selected from 1 to 8 hours, preferably 1 to 5 hours, and more preferably 1 to 3 hours.

[0048] The present invention provides a fluorine-modified graphene material obtained by the preparation method.

[0049] The present invention provides application of the fluorine-modified graphene material in preparing a polyimide film.

[0050] The present invention will be further described below with reference to the accompanying drawings and specific examples so that those skilled in the art can better understand the present invention and be able to implement it. However, the examples are not intended to limit the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art, the raw materials used are commercially available products, and the instruments used are conventional instruments in the art.

[0051] Atomization method: Use a 400mm vacuum glass desiccator. Place ammonia water, fluorine treatment agent, and atomizer at the bottom of the desiccator. Place a 400-mesh filter on top. Add powder A (pretreated graphene) and place a 400-mesh filter on top. Finally, apply vacuum through the air valve on the vacuum desiccator lid.

[0052] Example 1

[0053] This embodiment provides a fluorine-modified graphene material and a preparation method thereof, as follows:

[0054] (1) A method for preparing a fluorine-modified graphene material, comprising the following steps:

[0055] S1, first dissolve 0.2g of sodium lauryl sulfate in 180g of water, then add 16g of glucose and stir to dissolve, finally add 4g of graphene with an average particle size of 15μm and stir to disperse evenly;

[0056] S2, transfer the solution from step S1 into a sealed container and heat to 180°C for 12 hours;

[0057] S3, after the solution in step S2 is cooled to room temperature, it is filtered again and the filter cake is placed in an oven at 80°C to dry. When the water content of the filter cake powder is 5%, the drying is stopped and the powder A is obtained by crushing it with a grinder;

[0058] S4, using Figure 1 In this way, 50g of perfluorooctyltrimethoxysilane and 10g of 10wt% ammonia water were placed in two beakers respectively, and 50g of powder A was placed on top of the perfluorooctyltrimethoxysilane. The ultrasonic atomizer (1.7MHz) was set to a nebulization time of 10s, an interval time of 10min, and a volume of nebulized liquid per minute of the ultrasonic atomizer of 1.5mL. The atomization was turned on for a total of 120s, and then vacuumed for 3h. The treated powder A was then placed in a 120℃ oven and dried for 6h to obtain fluorine-modified graphene.

[0059] (2) Application of fluorine-modified graphene materials in polyimide films, specifically as follows:

[0060] 20 parts of fluorine-modified graphene were dispersed in 80 parts of N-methylpyrrolidone (NMP), and then all the dispersed slurry was added to 80 parts of BL-S220L. After stirring and ultrasonic dispersion, it was dropped onto a clean glass plate and scraped with a 1000um scraper. It was then placed in an 80°C oven and dried for 1 hour to remove the solvent. After drying in a muffle furnace at 200°C for 2 hours, the temperature was raised to 320°C and dried for 1 hour. After cooling, the film was removed in deionized water and dried in a 100°C oven for 30 minutes to obtain a composite polyimide film recorded as PI-1.

[0061] Control experiment (no modified graphene added): First, the BL-S220L polyimide solution (PAA) of Baolian (Shenzhen) Polyimide New Materials Co., Ltd. was dropped onto a clean glass plate, and then the film was scraped with a 1000um scraper. The film was then placed in an 80°C oven and dried for 1 hour to remove the solvent. After drying in a 200°C muffle furnace for 2 hours, the temperature was raised to 320°C and dried for 1 hour. After cooling, the film was removed in deionized water and dried in a 100°C oven for 30 minutes to obtain a polyimide film recorded as PI-0.

[0062] Structural characterization:

[0063] The transmission electron microscope JEM2100 was used to obtain the transmission electron micrograph of the unmodified graphene. Figure 2 As shown in Figure 2, before treatment, the graphene surface is clean and the structure appears soft. Figure 3 As shown, many active nanocarbons appear on the graphene surface, and the graphene structure appears rigid.

[0064] Performance Testing

[0065] (1) The surface resistance of the film was tested using a high resistance meter (KEITHLEY6514). The resistivity of PI-0 was 6.65×10 13 Ω·cm, PI-1 resistivity is 2.16×10 13 Ω·cm.

[0066] (2) The thermal conductivity of the film was tested using a laser thermal conductivity instrument (NETZSCH LFA467). The in-plane thermal conductivity of PI-0 was 0.19 W / (m·K), and the in-plane thermal conductivity of PI-1 was 2.26 W / (m·K).

[0067] Example 2

[0068] This embodiment provides a fluorine-modified graphene material and a preparation method thereof, as follows:

[0069] (1) A method for preparing a fluorine-modified graphene material, comprising the following steps:

[0070] S1, first dissolve 0.2g of sodium lauryl sulfate in 180g of water, then add 16g of glucose and stir to dissolve, finally add 3g of graphene with an average particle size of 15μm and stir to disperse evenly;

[0071] S2, transfer the solution from step S1 into a sealed container and heat to 180°C for 12 hours;

[0072] S3, after the solution in step S2 is cooled to room temperature, it is filtered again and the filter cake is placed in an oven at 80°C to dry. When the water content of the filter cake powder is 5%, the drying is stopped and the powder A is obtained by crushing it with a grinder;

[0073] S4, using Figure 1In this way, 50g of perfluorooctyltrimethoxysilane and 10g of 10wt% ammonia water were placed in two beakers respectively, and 50g of powder A was placed on top of the perfluorooctyltrimethoxysilane. The ultrasonic atomizer (1.7MHz) was set to a nebulization time of 10s, an interval time of 10min, and a volume of nebulized liquid per minute of the ultrasonic atomizer of 1.5mL. The atomization was turned on for a total of 120s, and then vacuumed for 3h. The treated powder A was then placed in a 120℃ oven and dried for 6h to obtain fluorine-modified graphene.

[0074] (2) Application of fluorine-modified graphene materials in polyimide films, specifically as follows:

[0075] 20 parts of fluorine-modified graphene were dispersed in 80 parts of NMP, and then all the dispersed slurry was added to 80 parts of BL-S220L. After stirring and ultrasonic dispersion, it was dropped onto a clean glass plate and scraped with a 1000 μm scraper. Then, it was placed in an 80 ° C oven to dry for 1 hour to remove the solvent. After drying in a muffle furnace at 200 ° C for 2 hours, the temperature was raised to 320 ° C and dried for 1 hour. After cooling, the film was removed in deionized water and dried in an oven at 100 ° C for 30 minutes. The composite polyimide film was recorded as PI-2 with a surface resistivity of 6.28×10 12 Ω·cm, thermal conductivity is 2.12W / (m·K).

[0076] Example 3

[0077] This embodiment provides a fluorine-modified graphene material and a preparation method thereof, as follows:

[0078] (1) A method for preparing a fluorine-modified graphene material, comprising the following steps:

[0079] S1, first dissolve 0.2g of sodium lauryl sulfate in 180g of water, then add 16g of glucose and stir to dissolve, finally add 2g of graphene with an average particle size of 15μm and stir to disperse evenly;

[0080] S2, transfer the solution from step S1 into a sealed container and heat to 180°C for 12 hours;

[0081] S3, after the solution in step S2 is cooled to room temperature, it is filtered again and the filter cake is placed in an oven at 80°C to dry. When the water content of the filter cake powder is 5%, the drying is stopped and the powder A is obtained by crushing it with a grinder;

[0082] S4, using Figure 1In this way, 50g of perfluorooctyltrimethoxysilane and 10g of 10wt% ammonia water were placed in two beakers respectively, and 50g of powder A was placed on top of the perfluorooctyltrimethoxysilane. The ultrasonic atomizer (1.7MHz) was set to a nebulization time of 10s, an interval time of 10min, and a volume of nebulized liquid per minute of the ultrasonic atomizer of 1.5mL. The atomization was turned on for a total of 120s, and then vacuumed for 3h. The treated powder A was then placed in a 120℃ oven and dried for 6h to obtain fluorine-modified graphene.

[0083] (2) Application of fluorine-modified graphene materials in polyimide films, specifically as follows:

[0084] 20 parts of fluorine-modified graphene were dispersed in 80 parts of NMP, and then all the dispersed slurry was added to 80 parts of BL-S220L. After stirring and ultrasonic dispersion, it was dropped onto a clean glass plate and scraped with a 1000 μm scraper. Then, it was placed in an 80 ° C oven to dry for 1 hour to remove the solvent. After drying in a muffle furnace at 200 ° C for 2 hours, the temperature was raised to 320 ° C and dried for 1 hour. After cooling, the film was removed in deionized water and dried in an oven at 100 ° C for 30 minutes. The composite polyimide film was recorded as PI-3 with a surface resistivity of 5.36×10 12 Ω·cm, thermal conductivity is 2.29W / (m·K).

[0085] Example 4

[0086] This embodiment provides a fluorine-modified graphene material and a preparation method thereof, as follows:

[0087] (1) A method for preparing a fluorine-modified graphene material, comprising the following steps:

[0088] S1, first dissolve 0.2g of sodium lauryl sulfate in 180g of water, then add 16g of glucose and stir to dissolve, finally add 4g of graphene with an average particle size of 10μm and stir to disperse evenly;

[0089] S2, transfer the solution from step S1 into a sealed container and heat to 180°C for 12 hours;

[0090] S3, after the solution in step S2 is cooled to room temperature, it is filtered again and the filter cake is placed in an oven at 80°C to dry. When the water content of the filter cake powder is 5%, the drying is stopped and the powder A is obtained by crushing it with a grinder;

[0091] S4, using Figure 1In this way, 50g of perfluorooctyltrimethoxysilane and 10g of 10wt% ammonia water were placed in two beakers respectively, and 50g of powder A was placed on top of the perfluorooctyltrimethoxysilane. The ultrasonic atomizer (1.7MHz) was set to a nebulization time of 10s, an interval time of 10min, and a volume of nebulized liquid per minute of the ultrasonic atomizer of 1.5mL. The atomization was turned on for a total of 120s, and then vacuumed for 3h. The treated powder A was then placed in a 120℃ oven and dried for 6h to obtain fluorine-modified graphene.

[0092] (2) Application of fluorine-modified graphene materials in polyimide films, specifically as follows:

[0093] 20 parts of fluorine-modified graphene were dispersed in 80 parts of NMP, and then all the dispersed slurry was added to 80 parts of BL-S220L. After stirring and ultrasonic dispersion, it was dropped onto a clean glass plate and scraped with a 1000 μm scraper. Then, it was placed in an 80 ° C oven to dry for 1 hour to remove the solvent. After drying in a muffle furnace at 200 ° C for 2 hours, the temperature was raised to 320 ° C and dried for 1 hour. After cooling, the film was removed in deionized water and dried in an oven at 100 ° C for 30 minutes to obtain a composite polyimide film named PI-4 with a surface resistivity of 1.68×10 13 Ω·cm, thermal conductivity is 2.06W / (m·K).

[0094] Example 5

[0095] This embodiment provides a fluorine-modified graphene material and a preparation method thereof, as follows:

[0096] (1) A method for preparing a fluorine-modified graphene material, comprising the following steps:

[0097] S1, first dissolve 0.2g of sodium lauryl sulfate in 180g of water, then add 16g of glucose and stir to dissolve, finally add 4g of graphene with an average particle size of 6μm and stir to disperse evenly;

[0098] S2, transfer the solution from step S1 into a sealed container and heat to 180°C for 12 hours;

[0099] S3, after the solution in step S2 is cooled to room temperature, it is filtered again and the filter cake is placed in an oven at 80°C to dry. When the water content of the filter cake powder is 5%, the drying is stopped and the powder A is obtained by crushing it with a grinder;

[0100] S4, using Figure 1In this way, 50g of perfluorooctyltrimethoxysilane and 10g of 10wt% ammonia water were placed in two beakers respectively, and 50g of powder A was placed on top of the perfluorooctyltrimethoxysilane. The ultrasonic atomizer (1.7MHz) was set to a nebulization time of 10s, an interval time of 10min, and a volume of nebulized liquid per minute of the ultrasonic atomizer of 1.5mL. The atomization was turned on for a total of 120s, and then vacuumed for 3h. The treated powder A was then placed in a 120℃ oven and dried for 6h to obtain fluorine-modified graphene.

[0101] (2) Application of fluorine-modified graphene materials in polyimide films, specifically as follows:

[0102] 20 parts of modified graphene were dispersed in 80 parts of NMP, and then all the dispersed slurry was added to 80 parts of BL-S220L. After stirring and ultrasonic dispersion, it was dropped onto a clean glass plate and scraped with a 1000 μm scraper. Then, it was placed in an 80 ° C oven to dry for 1 hour to remove the solvent. After drying in a muffle furnace at 200 ° C for 2 hours, the temperature was raised to 320 ° C and dried for 1 hour. After cooling, the film was removed in deionized water and dried in an oven at 100 ° C for 30 minutes. The obtained composite polyimide film was marked as PI-5 with a surface resistivity of 2.35×10 13 Ω·cm, thermal conductivity is 1.86W / (m·K).

[0103] Example 6

[0104] This embodiment provides a fluorine-modified graphene material and a preparation method thereof, as follows:

[0105] (1) A method for preparing a fluorine-modified graphene material, comprising the following steps:

[0106] S1, first dissolve 0.2g of sodium lauryl sulfate in 180g of water, then add 32g of glucose and stir to dissolve, finally add 4g of graphene with an average particle size of 15μm and stir to disperse evenly;

[0107] S2, transfer the solution from step S1 into a sealed container and heat to 180°C for 12 hours;

[0108] S3, after the solution in step S2 is cooled to room temperature, it is filtered again and the filter cake is placed in an oven at 80°C to dry. When the water content of the filter cake powder is 5%, the drying is stopped and the powder A is obtained by crushing it with a grinder;

[0109] S4, using Figure 1In this way, 50g of perfluorooctyltrimethoxysilane and 10g of 10wt% ammonia water were placed in two beakers respectively, and 50g of powder A was placed on top of the perfluorooctyltrimethoxysilane. The ultrasonic atomizer (1.7MHz) was set to a nebulization time of 10s, an interval time of 10min, and a volume of nebulized liquid per minute of the ultrasonic atomizer of 1.5mL. The atomization was turned on for a total of 120s, and then vacuumed for 3h. The treated powder A was then placed in a 120℃ oven and dried for 6h to obtain fluorine-modified graphene.

[0110] (2) Application of fluorine-modified graphene materials in polyimide films, specifically as follows:

[0111] 20 parts of fluorine-modified graphene were dispersed in 80 parts of NMP, and then all the dispersed slurry was added to 80 parts of BL-S220L. After stirring and ultrasonic dispersion, it was dropped onto a clean glass plate and scraped with a 1000 μm scraper. Then, it was placed in an 80 ° C oven to dry for 1 hour to remove the solvent. After drying in a muffle furnace at 200 ° C for 2 hours, the temperature was raised to 320 ° C and dried for 1 hour. After cooling, the film was removed in deionized water and dried in an oven at 100 ° C for 30 minutes to obtain a composite polyimide film named PI-6 with a surface resistivity of 4.62×10 13 Ω·cm, thermal conductivity is 1.92W / (m·K).

[0112] Example 7

[0113] This embodiment provides a fluorine-modified graphene material and a preparation method thereof, as follows:

[0114] (1) A method for preparing a fluorine-modified graphene material, comprising the following steps:

[0115] S1, first dissolve 0.2g of sodium lauryl sulfate in 180g of water, then add 8g of glucose and stir to dissolve, finally add 4g of graphene with an average particle size of 15μm and stir to disperse evenly;

[0116] S2, transfer the solution from step S1 into a sealed container and heat to 180°C for 12 hours;

[0117] S3, after the solution in step S2 is cooled to room temperature, it is filtered again and the filter cake is placed in an oven at 80°C to dry. When the water content of the filter cake powder is 5%, the drying is stopped and the powder A is obtained by crushing it with a grinder;

[0118] S4, using Figure 1In this way, 50g of perfluorooctyltrimethoxysilane and 10g of 10wt% ammonia water were placed in two beakers respectively, and 50g of powder A was placed on top of the perfluorooctyltrimethoxysilane. The ultrasonic atomizer (1.7MHz) was set to a nebulization time of 10s, an interval time of 10min, and a volume of nebulized liquid per minute of the ultrasonic atomizer of 1.5mL. The atomization was turned on for a total of 120s, and then vacuumed for 3h. The treated powder A was then placed in a 120℃ oven and dried for 6h to obtain fluorine-modified graphene.

[0119] (2) Application of fluorine-modified graphene materials in polyimide films, specifically as follows:

[0120] 20 parts of fluorine-modified graphene were dispersed in 80 parts of NMP, and then all the dispersed slurry was added to 80 parts of BL-S220L. After stirring and ultrasonic dispersion, it was dropped onto a clean glass plate and scraped with a 1000 μm scraper. Then, it was placed in an 80 ° C oven to dry for 1 hour to remove the solvent. After drying in a muffle furnace at 200 ° C for 2 hours, the temperature was raised to 320 ° C and dried for 1 hour. After cooling, the film was removed in deionized water and dried in an oven at 100 ° C for 30 minutes to obtain a composite polyimide film named PI-7 with a surface resistivity of 4.59×10 12 Ω·cm, thermal conductivity is 2.24W / (m·K).

[0121] Example 8

[0122] This embodiment provides a fluorine-modified graphene material and a preparation method thereof, as follows:

[0123] (1) A method for preparing a fluorine-modified graphene material, comprising the following steps:

[0124] S1, first dissolve 0.2g of sodium lauryl sulfate in 180g of water, then add 16g of glucose and stir to dissolve, finally add 4g of graphene with an average particle size of 15μm and stir to disperse evenly;

[0125] S2, transfer the solution from step S1 into a sealed container and heat to 160°C for 12 hours;

[0126] S3, after the solution in step S2 is cooled to room temperature, it is filtered again and the filter cake is placed in an oven at 80°C to dry. When the water content of the filter cake powder is 5%, the drying is stopped and the powder A is obtained by crushing it with a grinder;

[0127] S4, using Figure 1In this way, 50g of perfluorooctyltrimethoxysilane and 10g of 10wt% ammonia water were placed in two beakers respectively, and 50g of powder A was placed on top of the perfluorooctyltrimethoxysilane. The ultrasonic atomizer (1.7MHz) was set to a nebulization time of 10s, an interval time of 10min, and a volume of nebulized liquid per minute of the ultrasonic atomizer of 1.5mL. The atomization was turned on for a total of 120s, and then vacuumed for 3h. The treated powder A was then placed in a 120℃ oven and dried for 6h to obtain fluorine-modified graphene.

[0128] (2) Application of fluorine-modified graphene materials in polyimide films, specifically as follows:

[0129] 20 parts of fluorine-modified graphene were dispersed in 80 parts of NMP, and then all the dispersed slurry was added to 80 parts of BL-S220L. After stirring and ultrasonic dispersion, it was dropped onto a clean glass plate and scraped with a 1000 μm scraper. Then, it was placed in an 80 ° C oven to dry for 1 hour to remove the solvent. After drying in a muffle furnace at 200 ° C for 2 hours, the temperature was raised to 320 ° C and dried for 1 hour. After cooling, the film was removed in deionized water and dried in an oven at 100 ° C for 30 minutes to obtain a composite polyimide film named PI-8 with a surface resistivity of 3.23×10 13 Ω·cm, thermal conductivity is 2.16W / (m·K).

[0130] Example 9

[0131] This embodiment provides a fluorine-modified graphene material and a preparation method thereof, as follows:

[0132] (1) A method for preparing a fluorine-modified graphene material, comprising the following steps:

[0133] S1, first dissolve 0.2g of sodium lauryl sulfate in 180g of water, then add 16g of glucose and stir to dissolve, finally add 4g of graphene with an average particle size of 15μm and stir to disperse evenly;

[0134] S2, transfer the solution from step S1 into a sealed container and heat to 120°C for 12 hours;

[0135] S3, after the solution in step S2 is cooled to room temperature, it is filtered again and the filter cake is placed in an oven at 80°C to dry. When the water content of the filter cake powder is 5%, the drying is stopped and the powder A is obtained by crushing it with a grinder;

[0136] S4, using Figure 1In this way, 50g of perfluorooctyltrimethoxysilane and 10g of 10wt% ammonia water were placed in two beakers respectively, and 50g of powder A was placed on top of the perfluorooctyltrimethoxysilane. The ultrasonic atomizer (1.7MHz) was set to a nebulization time of 10s, an interval time of 10min, and a volume of nebulized liquid per minute of the ultrasonic atomizer of 1.5mL. The atomization was turned on for a total of 120s, and then vacuumed for 3h. The treated powder A was then placed in a 120℃ oven and dried for 6h to obtain fluorine-modified graphene.

[0137] (2) Application of fluorine-modified graphene materials in polyimide films, specifically as follows:

[0138] 20 parts of modified graphene were dispersed in 80 parts of NMP, and then all the dispersed slurry was added to 80 parts of BL-S220L. After stirring and ultrasonic dispersion, it was dropped onto a clean glass plate and scraped with a 1000 μm scraper. Then, it was placed in an 80 ° C oven to dry for 1 hour to remove the solvent. After drying in a muffle furnace at 200 ° C for 2 hours, the temperature was raised to 320 ° C and dried for 1 hour. After cooling, the film was removed in deionized water and dried in an oven at 100 ° C for 30 minutes. The obtained composite polyimide film was recorded as PI-9 with a surface resistivity of 3.69×10 13 Ω·cm, thermal conductivity is 2.15W / (m·K).

[0139] Example 10

[0140] This embodiment provides a fluorine-modified graphene material and a preparation method thereof, as follows:

[0141] (1) A method for preparing a fluorine-modified graphene material, comprising the following steps:

[0142] S1, first dissolve 0.2g of sodium lauryl sulfate in 180g of water, then add 16g of glucose and stir to dissolve, finally add 4g of graphene with an average particle size of 15μm and stir to disperse evenly;

[0143] S2, transfer the solution from step S1 into a sealed container and heat to 180°C for 12 hours;

[0144] S3, after the solution in step S2 is cooled to room temperature, it is filtered again and the filter cake is placed in an oven at 80°C to dry. When the water content of the filter cake powder is 5%, the drying is stopped and the powder A is obtained by crushing it with a grinder;

[0145] S4, using Figure 1In this way, 50g of perfluorooctyltrimethoxysilane and 10g of 10wt% ammonia water were placed in two beakers respectively, and 50g of powder A was placed on top of the perfluorooctyltrimethoxysilane. The ultrasonic atomizer (1.7MHz) was set to a nebulization time of 10s, an interval time of 10min, and a volume of nebulized liquid per minute of the ultrasonic atomizer of 1.5mL. The atomization was turned on for a total of 60s, and then vacuumed for 3h. The treated powder A was then placed in a 120℃ oven and dried for 6h to obtain fluorine-modified graphene.

[0146] (2) Application of fluorine-modified graphene materials in polyimide films, specifically as follows:

[0147] 20 parts of fluorine-modified graphene were dispersed in 80 parts of NMP, and then all the dispersed slurry was added to 80 parts of BL-S220L. After stirring and ultrasonic dispersion, it was dropped onto a clean glass plate and scraped with a 1000 μm scraper. Then, it was placed in an 80 ° C oven to dry for 1 hour to remove the solvent. After drying in a muffle furnace at 200 ° C for 2 hours, the temperature was raised to 320 ° C and dried for 1 hour. After cooling, the film was removed in deionized water and dried in an oven at 100 ° C for 30 minutes to obtain a composite polyimide film, which was recorded as PI-10 and had a surface resistivity of 1.12×10 12 Ω·cm, thermal conductivity is 2.20W / (m·K).

[0148] Example 11

[0149] This embodiment provides a fluorine-modified graphene material and a preparation method thereof, as follows:

[0150] (1) A method for preparing a fluorine-modified graphene material, comprising the following steps:

[0151] S1, first dissolve 0.2g of sodium lauryl sulfate in 180g of water, then add 16g of glucose and stir to dissolve, finally add 4g of graphene with an average particle size of 15μm and stir to disperse evenly;

[0152] S2, transfer the solution from step S1 into a sealed container and heat to 180°C for 12 hours;

[0153] S3, after the solution in step S2 is cooled to room temperature, it is filtered again and the filter cake is placed in an oven at 80°C to dry. When the water content of the filter cake powder is 5%, the drying is stopped and the powder A is obtained by crushing it with a grinder;

[0154] S4, using Figure 150g of perfluorooctyltrimethoxysilane and 10g of 10wt% ammonia water were placed in two beakers, and 50g of powder A was placed on top of the perfluorooctyltrimethoxysilane. The ultrasonic atomizer (1.7MHz) was set to a nebulization time of 10s, an interval of 10min, and a volume of 1.5mL of atomized liquid per minute. The atomization was turned on for a total of 360s, and then vacuum was applied for 3h. The treated powder A was then placed in a 120°C oven and dried for 6h to obtain fluorine-modified graphene.

[0155] (2) Application of fluorine-modified graphene materials in polyimide films, specifically as follows:

[0156] 20 parts of fluorine-modified graphene were dispersed in 80 parts of NMP, and then all the dispersed slurry was added to 80 parts of BL-S220L. After stirring and ultrasonic dispersion, it was dropped onto a clean glass plate and scraped with a 1000 μm scraper. Then, it was placed in an 80 ° C oven to dry for 1 hour to remove the solvent. After drying in a muffle furnace at 200 ° C for 2 hours, the temperature was raised to 320 ° C and dried for 1 hour. After cooling, the film was removed in deionized water and dried in an oven at 100 ° C for 30 minutes to obtain a composite polyimide film named PI-11 with a surface resistivity of 3.12×10 13 Ω·cm, thermal conductivity is 1.98W / (m·K).

[0157] Example 12

[0158] This embodiment provides a fluorine-modified graphene material and a preparation method thereof, as follows:

[0159] (1) A method for preparing a fluorine-modified graphene material, comprising the following steps:

[0160] S1, first dissolve 0.2g of sodium lauryl sulfate in 180g of water, then add 16g of sucrose and stir to dissolve, finally add 4g of graphene with an average particle size of 15μm and stir to disperse evenly;

[0161] S2, transfer the solution from step S1 into a sealed container and heat to 180°C for 12 hours;

[0162] S3, after the solution in step S2 is cooled to room temperature, it is filtered again and the filter cake is placed in an oven at 80°C to dry. When the water content of the filter cake powder is 5%, the drying is stopped and the powder A is obtained by crushing it with a grinder;

[0163] S4, using Figure 1In this way, 50g of perfluorooctyltrimethoxysilane and 10g of 10wt% ammonia water were placed in two beakers respectively, and 50g of powder A was placed on top of the perfluorooctyltrimethoxysilane. The ultrasonic atomizer (1.7MHz) was set to a nebulization time of 10s, an interval time of 10min, and a volume of nebulized liquid per minute of the ultrasonic atomizer of 1.5mL. The atomization was turned on for a total of 120s, and then vacuumed for 3h. The treated powder A was then placed in a 120℃ oven and dried for 6h to obtain fluorine-modified graphene.

[0164] (2) Application of fluorine-modified graphene materials in polyimide films, specifically as follows:

[0165] 20 parts of fluorine-modified graphene were dispersed in 80 parts of NMP, and then all the dispersed slurry was added to 80 parts of BL-S220L. After stirring and ultrasonic dispersion, it was dropped onto a clean glass plate and scraped with a 1000um scraper. Then it was placed in an 80°C oven and dried for 1 hour to remove the solvent. After drying in a muffle furnace at 200°C for 2 hours, the temperature was raised to 320°C and dried for 1 hour. After cooling, the film was removed in deionized water and dried in an oven at 100°C for 30 minutes to obtain a composite polyimide film named PI-12 with a surface resistivity of 1.92×1013Ω·cm and a thermal conductivity of 2.21w / (m·K).

[0166] Example 13

[0167] This embodiment provides a fluorine-modified graphene material and a preparation method thereof, as follows:

[0168] (1) A method for preparing a fluorine-modified graphene material, comprising the following steps:

[0169] S1, first dissolve 0.2g of sodium lauryl sulfate in 180g of water, then add 16g of glucose and stir to dissolve, finally add 4g of graphene with an average particle size of 15μm and stir to disperse evenly;

[0170] S2, transfer the solution from step S1 into a sealed container and heat to 180°C for 12 hours;

[0171] S3, after the solution in step S2 is cooled to room temperature, it is filtered again and the filter cake is dried in an oven at 80°C. When the water content of the powder is 5%, the drying is stopped and the powder is broken up with a grinder to obtain powder A;

[0172] S4, using Figure 1In this way, 50g of heptafluorodecyltrimethoxysilane and 10g of 10wt% ammonia water were placed in two beakers respectively, and 50g of powder A was placed on top of the heptafluorodecyltrimethoxysilane. The ultrasonic atomizer (1.7MHz) was set to a nebulization time of 10s, an interval time of 10min, and a volume of nebulized liquid per minute of the ultrasonic atomizer of 1.5mL. The atomization was turned on for a total of 120s, and then vacuumed for 3h. The treated powder A was then placed in a 120℃ oven and dried for 6h to obtain fluorine-modified graphene.

[0173] (2) Application of fluorine-modified graphene materials in polyimide films, specifically as follows:

[0174] 20 parts of fluorine-modified graphene were dispersed in 80 parts of NMP, and then all the dispersed slurry was added to 80 parts of BL-S220L. After stirring and ultrasonic dispersion, it was dropped onto a clean glass plate and scraped with a 1000 μm scraper. Then, it was placed in an 80 ° C oven to dry for 1 hour to remove the solvent. After drying in a muffle furnace at 200 ° C for 2 hours, the temperature was raised to 320 ° C and dried for 1 hour. After cooling, the film was removed in deionized water and dried in an oven at 100 ° C for 30 minutes to obtain a composite polyimide film named PI-13 with a surface resistivity of 2.48×10 13 Ω·cm, thermal conductivity is 2.19W / (m·K).

[0175] Table 1 Performance test results of polyimide films obtained from examples and control group samples

[0176]

[0177]

[0178] As can be seen from Table 1, the control sample PI-0 does not add fluorine-modified graphene. Compared with PI-0, the surface resistivity of PI-1 is very high and has not decreased significantly, and is still in the non-conductor region. The thermal conductivity is also greatly improved. This shows that the present invention can greatly improve the thermal conductivity of the polyimide film by adding fluorine-modified graphene while maintaining the electrical insulation of the polyimide film.

[0179] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for preparing a fluorine-modified graphene material, characterized in that: The following steps are involved: Mixing graphene, a carbon source, a surfactant, and water in a certain mass ratio and stirring to obtain a mixed solution; Transfer the mixed solution into a sealed reaction chamber and heat it for a period of time; Cooling, solid-liquid separation to obtain a solid phase, drying the obtained solid phase, and then crushing it to obtain powder A; A fluorine treatment agent is deposited on the surface of powder A by chemical vapor deposition to obtain fluorine-modified graphene; Place the fluorine treatment agent and ammonia water in two beakers respectively, place powder A on top of the fluorine treatment agent, place the ultrasonic atomizer in the beaker of the fluorine treatment agent, set the atomization time and interval time, then start atomization, and then vacuum, continue vacuuming for a period of time, and then place the treated powder A in an oven to dry for a period of time to obtain fluorine-modified graphene.

2. The method for preparing the fluorine-modified graphene material according to claim 1, wherein The graphene is liquid The phase-exfoliated graphene powder has a surface functional group content of less than 0.1wt%, a thickness of 0.35-2nm, and a particle size of 1-20um.

3. The method for preparing the fluorine-modified graphene material according to claim 1, wherein The carbon source is selected from one or more of citric acid, sodium citrate, cyclodextrin, lactose, fructose, glucose, sucrose, maltose, and starch.

4. The method for preparing the fluorine-modified graphene material according to claim 1, wherein The surfactant is selected from one or more of sodium dodecylbenzenesulfonate, sodium lauryl sulfate, and sodium lauryl polyoxyethylene ether sulfate.

5. The method for preparing the fluorine-modified graphene material according to claim 1, wherein The mass ratio of the graphene, carbon source, surfactant and water is 1-4:(8-32):0.1:

80.

6. The method for preparing the fluorine-modified graphene material according to claim 1, wherein: The reaction temperature in the sealed reaction chamber is 60-180° C., and the insulation time is 1-24 hours.

7. The method for preparing the fluorine-modified graphene material according to claim 1, wherein: The drying temperature is 60-100° C., and the water content of the powder A is 1-8 wt %.

8. The method for preparing the fluorine-modified graphene material according to claim 1, wherein The fluorine treatment agent is one or more of terminal hydroxyl fluorinated polysiloxane, terminal hydroxypropyl fluorinated polysiloxane, perfluorooctyltrimethoxysilane, perfluorooctyltriethoxysilane, 3,3,3,-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3,3,3-trifluoropropylmethyldimethoxysilane, heptadecafluorodecyltrimethoxysilane, and heptadecafluorodecyltriethoxysilane.

9. A fluorine-modified graphene material obtained by the preparation method according to any one of claims 1 to 8.

10. Use of the fluorine-modified graphene material according to claim 9 in the preparation of a polyimide film.

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