Fluorinated graphene-based surface treating agent with defect structure and application of fluorinated graphene-based surface treating agent

Abstract

The invention discloses a fluorinated graphene-based surface treating agent with a defect structure and application of the fluorinated graphene-based surface treating agent, and belongs to the technical field of surface treating agents. The surface treating agent comprises the following components in parts by mass: 5-10 parts of fluorinated graphene with a defect structure; 10 to 30 parts of dihydroxy perfluoropolyether; 10 to 30 parts of a silane coupling agent; and 60-100 parts of a fluorinated diluent. The fluorinated graphene with the defect structure adopted by the surface treating agent is high in fluorine grafting rate, and the defect structure of the fluorinated graphene and the dihydroxyl perfluoropolyether can be utilized to generate a synergistic effect to form a closely-packed uniform structure, so that the surface treating agent has excellent properties such as hydrophobicity, antifouling property, friction resistance and corrosion resistance.

Description

Technical Field

[0001] The invention relates to a fluorinated graphene-based surface treatment agent with a defect structure and application thereof, belonging to the technical field of surface treatment agents. Background Art

[0002] Fluorinated graphene (FG), a derivative of graphene, has attracted increasing attention. FG has a two-dimensional planar structure with carbon and fluorine atoms covalently bonded. FG possesses excellent physicochemical properties, such as good lubricity, low friction, superhydrophobicity, and low electrical conductivity, making it a promising material for the manufacture of protective coatings.

[0003] At present, researchers mostly use fluorine / nitrogen mixed gas as a fluorinating agent to prepare fluorinated graphene. Chinese patent CN116769344A discloses a method for preparing a fluorinated graphene / SiO2 / fluorosilane composite material and its application in the field of super-hydrophobic coatings. This method uses reduced graphene oxide as a raw material and fluorinates it with a fluorine / nitrogen mixed gas to prepare fluorinated graphene. Chinese patent CN112175477A discloses a fluorinated graphene / CeO2 nanocomposite modified anti-corrosion coating and a preparation method thereof. This method uses graphene oxide as a raw material and also uses a fluorine / nitrogen mixed gas to fluorinate graphene. In addition, there are also studies on the preparation of fluorinated graphene at room temperature and pressure using hydrofluoric acid as a fluorinating agent.

[0004] However, fluorination agents such as fluorine gas, xenon fluoride, and hydrofluoric acid are expensive and highly toxic reagents. There are great safety hazards in the process of reacting them with graphene oxide to prepare fluorinated graphene, which poses a great threat to humans and the environment. In addition, the existing methods cannot make fluorinated graphene have a defective structure, and the fluorine grafting rate is also low. During the application process, it is impossible to further improve the hydrophobic and antifouling properties and stability of the coating. Summary of the Invention

[0005] In response to the problems of poor hydrophobic and antifouling properties and low stability of surface treatment agents in the prior art due to the low fluorine grafting rate of the fluorinated graphene used and the inability to produce effective synergistic effects with other components in the formula through structure, the first object of the present invention is to provide a fluorinated graphene-based surface treatment agent with a defective structure. The fluorinated graphene with a defective structure used in the surface treatment agent has a high fluorine grafting rate, and its defective structure can be used to produce a synergistic effect with bishydroxy perfluoropolyether to form a tightly stacked uniform structure, thereby further improving the stability and hydrophobic and antifouling properties of the coating.

[0006] The second object of the present invention is to provide an application of a fluorinated graphene-based surface treatment agent with a defective structure. The method is simple in process and is conducive to industrial production, and the resulting coating can have excellent hydrophobic and anti-fouling properties, friction resistance and corrosion resistance.

[0007] In order to achieve the above technical objectives, the present invention provides a fluorinated graphene-based surface treatment agent with a defect structure, comprising the following components by weight: 5 to 10 parts of fluorinated graphene with a defect structure; 10 to 30 parts of bishydroxy perfluoropolyether; 10 to 30 parts of a silane coupling agent; and 60 to 100 parts of a fluorinated diluent.

[0008] The fluorinated graphene used in the formulation of the present invention can utilize its defect structure to produce a synergistic effect with bishydroxy perfluoropolyether. Specifically, the presence of chemical defects such as carboxyl and carbonyl groups in the fluorinated graphene will facilitate the chemical grafting of bishydroxy perfluoropolyether onto the fluorinated graphene, thereby promoting the uniform dispersion of the fluorinated graphene and further improving the hydrophobicity, antifouling, friction resistance, and corrosion resistance of the coating formed by the surface treatment agent. At the same time, due to the presence of physical pore defects with poor carbon chain connectivity, the bishydroxy perfluoropolyether can penetrate these pore defects and form a tightly packed, uniform structure, which is beneficial to the stability of the coating. The amounts of fluorinated graphene and bishydroxy perfluoropolyether also need to be controlled within the scope of the present invention. If the amount of fluorinated graphene is too small, the wear resistance and corrosion resistance of the surface treatment agent will be reduced. If the amount is too large, the fluorinated graphene will be unevenly dispersed, which may easily lead to increased surface roughness and cracking risk of the coating. If the amount of bishydroxy perfluoropolyether is too small, the stability and hydrophobicity of the surface treatment agent will be reduced.

[0009] As a preferred embodiment, the fluorinated graphene with defect structures has both physical and chemical defect structures, and a fluorine grafting rate greater than 20%. The defect structure and high fluorine grafting rate of the fluorinated graphene prepared by the present invention are conducive to significantly improving the performance of the surface treatment agent.

[0010] As a preferred solution, the preparation process of the fluorinated graphene with defect structures is as follows: graphene is mixed with an inorganic metal fluorinating agent and then modified by mechanical ball milling to obtain pre-fluorinated graphene; the pre-fluorinated graphene is then subjected to a hydrothermal fluorination reaction in a solution containing a mixed acid and water. In the technical solution of the present invention, the graphene is first pre-fluorinated using an inorganic metal fluoride as a fluorinating agent by mechanical ball milling activation modification to achieve a partial fluorination effect; then, a hydrothermal method is used to generate a large amount of steam under high temperature and high pressure, which cooperates with the mixed acid added during the hydrothermal process to generate various oxygen-containing functional groups such as hydroxyl, carboxyl, carbonyl, and epoxy groups during the fluorination process of the graphene, while also forming physical defect structures on the fluorinated graphene. More importantly, on the one hand, the various reactive oxygen-containing functional group chemical defects can serve as active sites to further effectively promote the fluorination of graphene (forming CF and C-F2 bonding modes), while on the other hand, the presence of physical hole defects can facilitate the fluorination intercalation reaction, thereby significantly improving the fluorine grafting rate. An increase in the fluorination grafting rate means a higher content of functional groups such as CF and / or -CF2, which effectively enhances the hydrophobicity and mechanical strength of the fluorinated graphene itself, thereby improving the hydrophobic, antifouling, and friction resistance of the surface treatment agent. Furthermore, the aforementioned method for preparing fluorinated graphene effectively avoids potential direct contact with highly toxic fluorinating agents such as fluorine gas or hydrogen fluoride, significantly reducing the risks of the production process.

[0011] As a preferred embodiment, the mechanical ball milling modification conditions are: a ball-to-material ratio of (5-10):1, a rotation speed of 200-300 r / min, and a ball milling time of 3-5 hours. Under the preferred mechanical ball milling modification conditions of the present invention, the fluorinated graphene can be fully activated and pre-fluorinated.

[0012] As a preferred embodiment, the inorganic metal fluorinating agent is at least one of sodium fluoride, potassium fluoride, calcium fluoride, lithium fluoride, silver fluoride, copper fluoride, and aluminum fluoride. The inorganic metal fluorinating agent used in the present invention can effectively avoid the use of fluorine gas and hydrogen fluoride while achieving efficient fluorination, greatly improving process safety. Sodium fluoride and / or potassium fluoride are further preferred.

[0013] As a preferred solution, the mass ratio of the graphene to the inorganic metal fluorinating agent is 1: (1~2); further preferably, the mass ratio of the graphene to the inorganic metal fluorinating agent is 1: (1.5~2); the mass ratio of the pre-fluorinated graphene to water is (3~5):100, and further preferably, the mass ratio of the pre-fluorinated graphene to water is (4~5):100.

[0014] As a preferred embodiment, the mixed acid comprises at least two of the following: sulfuric acid, nitric acid, hydrochloric acid, and phosphoric acid. Further preferred is a combination of at least one of sulfuric acid and nitric acid (3:2, v / v), hydrochloric acid and nitric acid (3:2, v / v), and phosphoric acid and nitric acid (3:2, v / v). Even more preferred is a mixture of sulfuric acid and nitric acid (3:2, v / v). Experiments have shown that the use of mixed acid solutions promotes the formation of physical and various chemical defects, effectively ensuring the fluorination of graphene and increasing the fluorination grafting rate. However, when using sulfuric acid, hydrochloric acid, phosphoric acid, or nitric acid alone, the graphene fluorination grafting rate is less than 15%, and the structural stability and hydrophobic and antifouling properties of the surface treatment agent cannot be effectively guaranteed.

[0015] As a preferred solution, the volume ratio of the mixed acid to water is (0.3-0.5):1.

[0016] As a preferred solution, the conditions for the hydrothermal fluorination reaction are: 160-200°C, reaction time of 18-24 hours, and reaction pressure of 1.0-5.0 MPa. The temperature and pressure of the hydrothermal fluorination reaction in the present invention have a direct impact on the defect structure of the fluorinated graphene. When the temperature or pressure of the hydrothermal fluorination reaction is too low, a large amount of steam cannot be effectively generated, thereby failing to form physical defect structures on the fluorinated graphene. At the same time, the chemical defect structures formed are also reduced, thereby reducing the stability and hydrophobic antifouling properties of the surface treatment agent.

[0017] As a preferred embodiment, the molecular weight of the bishydroxy perfluoropolyether is 1000-10000, and more preferably, the molecular weight of the bishydroxy perfluoropolyether is 3000-8000. Studies have found that when the molecular weight of the bishydroxy perfluoropolyether is small, due to its low viscosity, the fluorinated graphene is easier to disperse and more evenly dispersed, which will promote the physical and chemical bonding of the fluorinated graphene and the bishydroxy perfluoropolyether, and is beneficial to the stability of the surface coating. When the molecular weight exceeds 10000, the viscosity of the bishydroxy perfluoropolyether increases significantly and the fluidity decreases, making it difficult to disperse the fluorinated graphene, which is not conducive to the formation of a uniform structure.

[0018] As a preferred solution, the silane coupling agent includes at least one of aminopropyltriethoxysilane, aminopropyltrimethoxysilane, aminopropylmethyldiethoxysilane, aminoethylaminopropyltrimethoxysiloxane, aminoethylaminopropyltriethoxysilane and aminoethylaminopropylmethyldimethoxysilane.

[0019] As a preferred solution, the fluorinated diluent includes at least one of 3M7100, 3M7200 and 3M7300.

[0020] The present invention also provides an application of a fluorinated graphene-based surface treatment agent with a defect structure, which is applied to the surface of a substrate of a metal, alloy or plastic cover plate.

[0021] As a preferred solution, the application process is: applying the surface treatment agent to the surface of the substrate by spraying or spin coating, and then curing it.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The present invention uses inorganic metal fluorides as fluorinating agents, and replaces the traditional method of directly using fluorine gas or hydrogen fluoride to fluorinate graphene through a high-temperature and high-pressure hydrothermal reaction. This avoids the potential direct contact of technicians with highly toxic fluorinating agents such as fluorine gas or hydrogen fluoride, effectively reduces the danger of the production process, and is more suitable for large-scale production.

[0024] (2) The present invention generates a large amount of steam under high temperature and high pressure, which in conjunction with the mixed acid added during the hydrothermal process, enables graphene to generate a variety of oxygen-containing functional groups such as hydroxyl, carboxyl, carbonyl, and epoxy groups during the fluorination process, while also forming physical defect structures on the fluorinated graphene. More importantly, on the one hand, the chemical defects such as the above-mentioned various oxygen-containing functional groups can serve as active sites to further effectively promote the fluorination of graphene (forming CF and C-F2 bonding modes), while on the other hand, the presence of physical hole defects can facilitate the fluorination intercalation reaction, thereby significantly improving the fluorine grafting rate.

[0025] (3) After the surface treatment agent provided by the present invention acts on the surface of the substrate and solidifies into a film, the coating has excellent hydrophobic and antifouling properties, with a water contact angle greater than 123°. Moreover, after 12,000 friction cycles or 96 hours of alkali solution immersion, the water contact angle is greater than 102°. In a further preferred embodiment, the water contact angle is greater than 110°, indicating that it has excellent friction and corrosion resistance.

[0026] (4) The fluorinated graphene used in the surface treatment agent of the present invention can utilize its defect structure to produce a synergistic effect with the bishydroxy perfluoropolyether. The presence of chemical defects such as carboxyl and carbonyl groups in the fluorinated graphene will facilitate the grafting of the bishydroxy perfluoropolyether onto the fluorinated graphene in a chemically bonded manner, thereby facilitating the uniform dispersion of the fluorinated graphene and further improving the performance of the coating formed by the surface treatment agent in terms of hydrophobicity, antifouling, friction resistance, and corrosion resistance. At the same time, due to the presence of physical pore defects with poor carbon chain connection, the bishydroxy perfluoropolyether can penetrate these pore defects and form a tightly packed uniform structure, which is beneficial to the stability of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1This is the XPS fine spectrum of the fluorinated graphene C 1S with defective structure prepared in Example 1.

[0028] Figure 2 This is a TEM image of the fluorinated graphene with defective structure prepared in Example 1 of the present invention.

[0029] Figure 3 These are comparative pictures of the graphene dispersion in the surface treatment agents prepared in Example 1, Comparative Example 2, and Comparative Example 6. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be further described below in conjunction with specific embodiments of the present invention. It should be noted that the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments; these embodiments are only for a better understanding of the present invention, and do not limit the scope of protection of the present invention.

[0031] Unless otherwise specified, all reagents and raw materials used in the present invention are commercially available products or products that can be prepared by known methods.

[0032] The room temperature of the present invention is 25°C.

[0033] Example 1

[0034] This embodiment provides a fluorinated graphene-based surface treatment agent with a defect structure, which is obtained by mixing 8 parts of fluorinated graphene with a defect structure, 20 parts of bishydroxy perfluoropolyether (Mn=3000, purchased from Fuzhou Taipuda New Materials Co., Ltd.), 20 parts of aminopropyltrimethoxysilane, and 70 parts of a fluorinated diluent 3M7100, stirring uniformly, and then ultrasonicating for 20 minutes.

[0035] The preparation process of fluorinated graphene with defective structure is as follows:

[0036] Step S1: 4 g of graphene powder and 6 g of sodium fluoride were weighed, mixed evenly, and then subjected to mechanical ball milling modification (ball-to-material ratio 10:1, speed 200 r / min, ball milling time 3 h) to obtain pre-fluorinated graphene;

[0037] Step S2: Disperse 4g of pre-fluorinated graphene in 100ml of deionized water. After uniform dispersion, transfer the mixture to a sealed hydrothermal reactor lined with tetrafluoroethylene. Add 40ml of a 3:2 sulfuric acid-nitric acid mixed solution via a self-contained line. The reaction was heated to 180°C and the reaction pressure was 3.1 MPa. Fluorination was initiated for 20 hours. After the reaction, the product was filtered, washed three times with deionized water and anhydrous ethanol, and then freeze-dried. The resulting fluorinated graphene had a fluorine grafting yield of 28.14%.

[0038] Example 2

[0039] This embodiment provides a fluorinated graphene-based surface treatment agent with a defect structure, which is obtained by mixing 5 parts of fluorinated graphene with a defect structure, 10 parts of bishydroxy perfluoropolyether (Mn=1000, purchased from Hunan Weisbangya Trading Co., Ltd. DIA-10), 10 parts of aminopropyltrimethoxysilane, and 60 parts of a fluorinated diluent 3M 7200, stirring uniformly, and then ultrasonicating for 20 minutes.

[0040] The preparation process of fluorinated graphene with defective structure is as follows:

[0041] Step S1: 3 g of graphene powder and 3 g of potassium fluoride were weighed, mixed evenly, and then subjected to mechanical ball milling modification (ball-to-material ratio 10:1, speed 200 r / min, ball milling time 3 h) to obtain pre-fluorinated graphene;

[0042] Step S2: Disperse 3g of pre-fluorinated graphene in 100ml of deionized water. After uniform dispersion, transfer the mixture to a sealed hydrothermal reactor lined with tetrafluoroethylene. Add 30ml of a mixed sulfuric acid-nitric acid solution (3:2, v / v) via a self-contained line. The reaction was heated to 160°C and the reaction pressure was 2.8 MPa. Fluorination was initiated for 18 hours. After the reaction, the product was filtered, washed three times with deionized water and anhydrous ethanol, and then freeze-dried to obtain fluorinated graphene. The resulting fluorinated graphene had a fluorine grafting yield of 26.53%.

[0043] Example 3

[0044] This embodiment provides a fluorinated graphene-based surface treatment agent with a defect structure, which is obtained by mixing 10 parts of fluorinated graphene with a defect structure, 30 parts of bishydroxy perfluoropolyether (Mn=5000, purchased from Fuzhou Taipuda New Materials Co., Ltd.), 30 parts of aminopropyltriethoxysilane, and 80 parts of a fluorinated diluent 3M 7100, stirring uniformly, and then ultrasonicating for 20 minutes.

[0045] The preparation process of fluorinated graphene with defective structure is as follows:

[0046] Step S1: 5 g of graphene powder and 10 g of lithium fluoride were weighed, mixed evenly, and then subjected to mechanical ball milling modification (ball-to-material ratio 10:1, speed 200 r / min, ball milling time 5 h) to obtain pre-fluorinated graphene;

[0047] Step S2: Disperse 5g of pre-fluorinated graphene in 100ml of deionized water. After uniform dispersion, transfer the mixture to a sealed hydrothermal reactor lined with tetrafluoroethylene. Add 50ml of a 3:2 (v / v) phosphoric acid-nitric acid mixed solution via a self-contained line. The reaction was heated to 200°C and the reaction pressure was 3.2 MPa. Fluorination was initiated for 24 hours. After the reaction, the product was filtered, washed three times with deionized water and anhydrous ethanol, and then freeze-dried to obtain fluorinated graphene. The resulting fluorinated graphene had a fluorine grafting yield of 23.81%.

[0048] Example 4

[0049] This embodiment provides a fluorinated graphene-based surface treatment agent with a defect structure, which is obtained by mixing 7 parts of fluorinated graphene with a defect structure, 20 parts of bishydroxy perfluoropolyether (Mn=10000, purchased from Fuzhou Taipuda New Materials Co., Ltd.), 20 parts of aminoethylaminopropyltrimethoxysiloxane, and 100 parts of a fluorinated diluent 3M 7300, stirring uniformly, and then ultrasonicating for 20 minutes.

[0050] The preparation process of fluorinated graphene with defective structure is as follows:

[0051] Step S1: 4.5 g of graphene powder and 6 g of potassium fluoride were weighed, mixed evenly, and then subjected to mechanical ball milling modification (ball-to-material ratio 10:1, speed 200 r / min, ball milling time 4 h) to obtain pre-fluorinated graphene;

[0052] Step S2: Disperse 4g of pre-fluorinated graphene in 100ml of deionized water. After uniform dispersion, transfer the mixture to a sealed hydrothermal reactor lined with tetrafluoroethylene. Add 40ml of a 3:2, v / v hydrochloric acid-nitric acid mixture via a self-contained line. The reaction was heated to 180°C and the reaction pressure was 3.5MPa. Fluorination was initiated for 20 hours. After the reaction, the product was filtered, washed three times with deionized water and anhydrous ethanol, and then freeze-dried to obtain fluorinated graphene. The fluorine grafting rate of the resulting fluorinated graphene was 26.25%.

[0053] Example 5

[0054] The only difference between this embodiment and embodiment 1 is that room temperature curing is used instead of heat curing, and the remaining preparation steps are the same. The fluorine grafting rate of the obtained fluorinated graphene is 28.09%.

[0055] Comparative Example 1

[0056] The difference between this comparative example and Example 1 is that no mechanical ball milling modification is performed, but the graphene powder and sodium fluoride are directly dispersed in deionized water, immersed for 4 hours and then filtered, and the other preparation steps are the same.

[0057] Comparative Example 2

[0058] Compared with Example 1, this comparative example differs in that the fluorinated graphene with defective structure is replaced by unmodified graphene powder raw material, and the remaining preparation steps are the same.

[0059] Comparative Example 3

[0060] Compared with Example 1, this comparative example differs in that the sulfuric acid-nitric acid solution in step S1 is replaced with an equal volume of sulfuric acid, and the remaining preparation steps are the same.

[0061] Comparative Example 4

[0062] The difference between this comparative example and Example 1 is that the reaction temperature in step S2 is adjusted to 100° C., and the other preparation steps are the same.

[0063] Comparative Example 5

[0064] The only difference between this comparative example and Example 1 is that no fluorinated graphene with a defective structure is added to the surface treatment agent, and the remaining preparation steps are the same.

[0065] Comparative Example 6

[0066] The difference between this comparative example and Example 1 is that no bishydroxy perfluoropolyether is added to the surface treatment agent, and the other preparation steps are the same.

[0067] The surface treatment agents prepared in Examples 1 to 5 and Comparative Examples 1 to 6 were uniformly and precisely applied to the surface of the substrate by spraying, and then cured at 80° C. for 4 hours.

[0068] The initial water contact angle of the substrate surface and the water contact angle after steel wool friction and alkali solution immersion were tested to verify the hydrophobicity, antifouling, friction resistance, and corrosion resistance of the surface treatment agents obtained in each embodiment or comparative example. The test results are shown in Table 1 below.

[0069]

[0070] Initial water contact angle test method: The static contact angle of the coating was measured using a JGW-360a contact angle meter. The test liquid volume was 2 μL, the test environment was 24 ± 1°C, and the relative humidity was 45 ± 1%. The water contact angle was measured at five points and the average value was taken.

[0071] Steel wool abrasion resistance test method: The steel wool abrasion resistance test is measured by a ZJ-339-GSR abrasion tester. The coated substrate is fixed on the tester, the pressure is set to 1000g, the stroke is set to 40mm, the speed is 40 cycles / min, and the test results are recorded after the test.

[0072] Alkali resistance test method: Under room temperature, soak the surface-treated substrate sample in a 2wt% sodium hydroxide solution (pH = 9.7~10). Take it out and test the water contact angle of the surface after cleaning every 2 hours. The test is terminated when the contact angle is lower than 110°.

[0073] As shown in Table 1, the surface treatment agents prepared by Examples 1 to 5 all showed excellent hydrophobic properties after acting on the surface of the substrate, with initial water contact angles greater than 123°, and after rubbing steel wool 12,000 times and soaking in alkali solution for 96 hours, the water contact angles were still greater than 102°, indicating that they had excellent properties such as friction resistance and corrosion resistance. After heat curing treatment, FG underwent slight surface migration, forming a rough micron / nanostructure, thereby showing excellent hydrophobic and friction resistance. In Example 5, since heat curing treatment was not performed, its friction resistance and corrosion resistance decreased to a certain extent. Comparative Examples 1, 3, and 4 had insufficient degree of graphene fluorination, Comparative Example 2 had no fluorination of graphene, and Comparative Example 5 had no addition of fluorinated graphene with a defective structure, resulting in a significant decrease in its hydrophobicity, friction resistance, and corrosion resistance. In addition, by comparing the results of Comparative Examples 5 and 6 with those of Example 1, it can be seen that the presence of fluorinated graphene and bishydroxy perfluoropolyether can greatly enhance the friction resistance and corrosion resistance of the coating.

[0074] The fluorinated graphene prepared in Example 1 was analyzed by XPS. The XPS fine spectrum of C 1S is as follows: Figure 1 As shown. The peaks at 284.2eV, 284.7eV, 286.2eV, 287.4eV, 289.1eV and 291.1eV correspond to the characteristic peaks of six chemical bonds, namely C=C, CC, CO, C=O, CF and C-F2, respectively. This result shows that the fluorinated graphene was successfully prepared. From the TEM results, we can see that ( Figure 2 ), fluorinated graphene obviously has certain physical defect structures, which will be conducive to the effective combination of fluorinated graphene and bishydroxy perfluoropolyether and promote their dispersion, effectively improving the stability of the surface treatment agent. Figure 3 This shows the excellent stability of the surface treatment agent prepared in the example, while in Comparative Example 2, only the unmodified graphene powder raw material solution was added, and there was obvious silver stratification. In Comparative Example 6, no bishydroxy perfluoropolyether was added, and there was also obvious stratification.

[0075] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features thereof can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fluorinated graphene-based surface treatment agent having a defective structure, characterized in that: The invention comprises the following components by weight: 5 to 10 parts of fluorinated graphene with defective structure; 10 to 30 parts of bishydroxy perfluoropolyether; and 10 to 30 parts of silane coupling agent. 60~100 parts of fluorinated diluent 2. The fluorinated graphene-based surface treatment agent having a defective structure according to claim 1, characterized in that: The fluorinated graphene with defective structure has both physical defective structure and chemical defective structure, and the grafting rate of fluorine is greater than 20%.

3. The fluorinated graphene-based surface treatment agent having a defective structure according to claim 1 or 2, characterized in that: The preparation process of the fluorinated graphene with defective structure is as follows: graphene is mixed with an inorganic metal fluorinating agent and then modified by mechanical ball milling to obtain pre-fluorinated graphene; the pre-fluorinated graphene is obtained by hydrothermal fluorination reaction in a solution containing mixed acid and water.

4. The fluorinated graphene-based surface treatment agent having a defect structure according to claim 3, characterized in that: The conditions for the mechanical ball milling modification are: a ball-to-material ratio of (5-10):1, a rotation speed of 200-300 r / min, and a ball milling time of 3-5 h.

5. The fluorinated graphene-based surface treatment agent having a defective structure according to claim 4, characterized in that: The inorganic metal fluoriding agent is at least one of sodium fluoride, potassium fluoride, calcium fluoride, lithium fluoride, silver fluoride, copper fluoride and aluminum fluoride.

6. The fluorinated graphene-based surface treatment agent having a defective structure according to claim 3, characterized in that: The mass ratio of the graphene to the inorganic metal fluorinating agent is 1:(1-2); the mass ratio of the pre-fluorinated graphene to water is (3-5):

100.

7. The fluorinated graphene-based surface treatment agent having a defect structure according to claim 4, characterized in that: The mixed acid includes at least two of sulfuric acid, nitric acid, hydrochloric acid and phosphoric acid; The volume ratio of the mixed acid to water is (0.3-0.5):

1.

8. The fluorinated graphene-based surface treatment agent having a defective structure according to claim 3, characterized in that: The conditions of the hydrothermal fluorination reaction are: 160-200° C., reaction time 18-24 h, and reaction pressure 1.0-5.0 MPa.

9. The fluorinated graphene-based surface treatment agent having a defective structure according to claim 8, characterized in that: The molecular weight of the bishydroxy perfluoropolyether is 1000 to 10000; The silane coupling agent includes at least one of aminopropyltriethoxysilane, aminopropyltrimethoxysilane, aminopropylmethyldiethoxysilane, aminoethylaminopropyltrimethoxysiloxane, aminoethylaminopropyltriethoxysilane and aminoethylaminopropylmethyldimethoxysilane; The fluorinated diluent includes at least one of 3M7100, 3M7200 and 3M7300.

10. Use of a fluorinated graphene-based surface treatment agent having a defective structure according to any one of claims 1 to 9, characterized in that: Applied to the substrate surface of metal, alloy or plastic cover.

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