Amphiphilic graphene and preparation method therefor

Abstract

Disclosed in the present invention are amphiphilic modified graphene and a preparation method therefor. The preparation method comprises: firstly, mixing an ether compound containing a hydroxyl group or an amino group with an epoxy raw material, and heating and stirring same to undergo reaction, so as to obtain a primary product with an end group being an epoxy group; mixing the primary product with diamine, heating and stirring same to undergo reaction, so as to obtain a graphene modifier with the end group being an amino group; and finally, mixing the graphene modifier with graphene, and subjecting same to a ring-opening reaction while heating and stirring, so as to obtain an amphiphilic modified graphene. In the present invention, the ring-opening reaction is used as the reaction principle, the amino group in the modifier reacts with the epoxy group and the carboxyl group on a graphene sheet, and thus the reaction is simple, the conditions are mild, and the obtained amphiphilic modified graphene can be stably dispersed in both an aqueous solvent and an oily solvent.

Description

[Corrected 08.02.2025 according to Rule 26] An amphiphilic graphene and its preparation method Technical Field

[0001] The present invention belongs to the technical field of graphene modification technology, and particularly relates to amphiphilic modified graphene and a preparation method thereof. Background Art

[0002] Graphene has many excellent properties, such as excellent electrical conductivity, heat resistance, mechanical properties, chemical stability and anti-penetration properties. 2 The large π bonds formed by the delocalization of hybrid carbon atoms inside graphene allow electrons to be efficiently transported inside, making the electrical conductivity of graphene as high as 10 6 Ω / m. Graphene has a high thermal conductivity at room temperature, reaching 5000W·m -1 ·K -1 Graphene's robust honeycomb structure also provides excellent mechanical properties, with a tensile strength of up to 130 GPa and a Young's modulus of 1.0 TPa. Graphene's two-dimensional flake form, stable chemical structure, and large specific surface area effectively inhibit the penetration of corrosive media, demonstrating promising application prospects in coatings and corrosion protection.

[0003] Defect-free graphene has excellent overall properties, but due to its extremely high specific surface area, it is prone to agglomeration. Furthermore, its chemical inertness makes it less compatible with polymers, which results in graphene easily agglomerating and even forming defects when mixed with polymers. This greatly limits its application. Therefore, current research focuses on preparing functionalized graphene by surface modification, thereby improving the compatibility of graphene with polymers and achieving a better dispersion effect.

[0004] Current research on graphene functionalization focuses on three main approaches: covalent modification, non-covalent modification, and inorganic nanoparticle modification. For example, patent CN116790138A discloses a method for preparing modified graphene and a modified graphene slurry. The method describes the use of chemical modification to graft organic molecular chains onto graphene, thereby improving its dispersibility in waterborne polyurethane. The modified graphene is then used as a raw material and in-situ emulsified with a waterborne polyurethane prepolymer to produce a modified graphene slurry. Patent CN108570072B discloses a method for phosphonic acid-modified graphene or phosphonate-modified graphene. This method first dissolves an aminophosphonate in a solvent, controls the temperature, adds sodium nitrite and an acid, and stirs evenly. Graphene is then added to react to obtain phosphonate-modified graphene. The acidity of the phosphonate-modified graphene is then adjusted to obtain phosphonic acid-modified graphene, thereby increasing the hydrophilicity of the graphene and enabling the industrial production of large-scale synthetic preparations of phosphonic acid-modified graphene or phosphonate-modified graphene. Patent CN117303357A discloses a method for preparing graphene suitable for oily systems. An imidazole ionic liquid, graphene, and a solvent are mixed and ball-milled to obtain imidazole ionic liquid-functionalized graphene. Patent CN115818629A discloses a super-amphiphilic graphene and its preparation method and application. Wood powder, ferric chloride, zinc chloride and an ionic liquid containing tetrafluoroborate anions are mixed and then pyrolyzed in an inert atmosphere to obtain the super-amphiphilic graphene. The super-amphiphilic graphene is used to prepare Pickering emulsions or in Pickering emulsion catalysis.

[0005] Currently, modified graphene is mostly dispersed in a single aqueous or oily solvent, and there is a lack of research on amphiphilic graphene, which limits the wide application of graphene. Summary of the Invention

[0006] The present invention is proposed to solve the problem in the prior art that modified graphene is mostly dispersed in a single solvent, either aqueous or oily, and its purpose is to provide an amphiphilic modified graphene and a preparation method thereof.

[0007] The present invention is achieved through the following technical solutions:

[0008] A method for preparing amphiphilic modified graphene comprises the following steps:

[0009] (i) Grafting epoxy group reaction

[0010] The ether compound containing hydroxyl or amino group is mixed with epoxy raw material, heated and stirred to react, and the primary product with epoxy end group is obtained;

[0011] (ii) Grafting amino group reaction

[0012] The primary product having an epoxy end group obtained in step (i) is mixed with a diamine, and the mixture is heated and stirred to react to obtain a graphene modifier having an amino end group;

[0013] (iii) Modified graphene reaction

[0014] The graphene modifier obtained in step (ii) is mixed with the graphene dispersion, and a ring-opening reaction occurs under heating and stirring conditions to obtain amphiphilic modified graphene.

[0015] In the above technical solution, the reaction raw materials of step (i) are vacuum heated and dried before the reaction; the vacuum heating and drying temperature is 50° C. and the duration is 1 hour.

[0016] In the above technical solution, the molar ratio of the ether compound containing hydroxyl or amino group to the epoxy raw material in step (i) is 1:2 to 3:4.

[0017] In the above technical solution, the ether compound containing hydroxyl or amino group is polyetheramine or polyethylene glycol; the epoxy raw material is any one or more of E51, E44, 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether or 1,6-hexanediol diglycidyl ether.

[0018] In the above technical solution, the reaction starting materials of step (i) also include a catalyst; the catalyst is boron trifluoride etherate.

[0019] In the above technical solution, the added mass of the catalyst is 0.1% to 0.5% of the total mass of the ether compound containing hydroxyl or amino group and the epoxy raw material.

[0020] In the above technical solution, the diamine is any one or more of ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine; the addition ratio of the diamine to the primary product having an epoxy end group is (2-2.5):1.

[0021] In the above technical solution, the graphene dispersion is a graphene ethanol solution with a concentration of 1 mg / mL, and the mass ratio of the graphene modifier to the graphene dispersion is (2-5):1.

[0022] In the above technical solution, the stirring rates of steps (i), (ii) and (iii) are all 200 r / min to 2000 r / min; the heating temperatures are all 60° C. to 90° C., and the reaction times are all 4 h to 6 h.

[0023] An amphiphilic modified graphene is prepared by the above method.

[0024] The beneficial effects of the present invention are:

[0025] The present invention provides an amphiphilic modified graphene dispersible in an aqueous and oily solvent system and a preparation method thereof. The invention adopts a ring-opening reaction as the reaction principle and utilizes the amino groups in the modifier to react with the epoxy groups and carboxyl groups on the graphene sheets. The reaction is simple and the conditions are mild. The dispersibility of the graphene powder in both aqueous and oily solvents can be improved simultaneously, avoiding the use of a dispersant. The modified graphene can be later applied to coatings, thereby providing a research basis for the application of graphene in the fields of aqueous and oily coatings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG1 is an infrared structure spectrum of the amphiphilic modified graphene powder and the unmodified graphene powder prepared in Example 1 of the present invention;

[0027] Figure 2 is a diagram of the dispersion effects of the amphiphilic modified graphene powder and unmodified graphene powder prepared in Example 1 of the present invention in water and n-hexane solvent, respectively (a is the dispersion of unmodified graphene powder in water; b is the dispersion of unmodified graphene powder in n-hexane solvent; c is the dispersion of amphiphilic modified graphene powder in water; d is the dispersion of amphiphilic modified graphene powder).

[0028] For ordinary technicians in this field, other relevant drawings can be obtained based on the above drawings without any creative work. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0030] Unless otherwise specified, all reagents used in the examples can be purchased from the market.

[0031] Example 1

[0032] (i) Drying of raw materials

[0033] Place polyethylene glycol and E51 in a vacuum at 50°C for 1 h and store in a sealed bottle for later use.

[0034] (ii) Grafting epoxy group reaction

[0035] 0.1 mol of polyethylene glycol, 0.2 mol of E51 and an appropriate amount of boron trifluoride ether obtained in step (i) were heated under stirring conditions and reacted for a period of time at a stirring speed of 200 r / min, a reaction temperature of 60°C and a reaction time of 4 h to obtain a primary product with an epoxy end group.

[0036] (iii) Grafting amino group reaction

[0037] 0.2 mol of ethylenediamine was added to the product obtained in step (ii), and the mixture was heated under stirring for a period of time at a stirring speed of 200 r / min, a reaction temperature of 60° C., and a reaction time of 4 h to obtain a modifier having an amino group as an external group;

[0038] (iv) Modified graphene reaction

[0039] Add an appropriate amount of graphene powder to the product obtained in step (iii), heat it under stirring, react for a period of time, the stirring speed is 200r / min, the reaction temperature is 60°C, the reaction time is 4h, and the amphiphilic modified graphene is obtained by filtering and washing.

[0040] The infrared structure spectrum of the prepared amphiphilic modified graphene is shown in FIG1 . As can be seen from FIG1 , the infrared structure spectrum of the amphiphilic modified graphene has a wavelength of 2931 cm -1 and 2852cm -1 Characteristic peaks are the methylene structures in the modifier. The infrared structure spectrum of unmodified graphene powder does not have such characteristic peaks, which indicates that the graphene has been successfully modified.

[0041] The amphiphilic modified graphene powder prepared in this example and the unmodified graphene powder were dispersed in water and n-hexane solvent, respectively. The results are shown in FIG2 . It can be seen that the amphiphilic modified graphene powder prepared in this example is stably dispersed in both water and n-hexane solvent.

[0042] Example 2

[0043] (i) Drying of raw materials

[0044] Polyethylene glycol and 1,4-butanediol diglycidyl ether were vacuum-treated at 50°C for 1 h and stored in a sealed bottle for later use.

[0045] (ii) Grafting epoxy group reaction

[0046] 0.1 mol of polyethylene glycol, 0.2 mol of 1,4-butanediol diglycidyl ether and an appropriate amount of boron trifluoride ether obtained in step (i) were heated under stirring conditions and reacted for a period of time at a stirring speed of 200 r / min, a reaction temperature of 60°C, and a reaction time of 4 h to obtain a primary product with an epoxy end group.

[0047] (iii) Grafting amino group reaction

[0048] 0.2 mol of ethylenediamine was added to the product obtained in step (ii), and the mixture was heated under stirring for a period of time at a stirring speed of 200 r / min, a reaction temperature of 60° C., and a reaction time of 4 h to obtain a modifier having an amino group as an external group;

[0049] (iv) Modified graphene reaction

[0050] Add an appropriate amount of graphene powder to the product obtained in step (iii), heat it under stirring, react for a period of time, the stirring speed is 200r / min, the reaction temperature is 60°C, the reaction time is 4h, and the amphiphilic modified graphene is obtained by filtering and washing.

[0051] Example 3

[0052] (i) Drying of raw materials

[0053] Polyethylene glycol and 1,4-butanediol diglycidyl ether were vacuum-treated at 50°C for 1 h and stored in a sealed bottle for later use.

[0054] (ii) Grafting epoxy group reaction

[0055] 0.1 mol of polyethylene glycol, 0.2 mol of 1,4-butanediol diglycidyl ether and an appropriate amount of boron trifluoride ether obtained in step (i) were heated under stirring conditions and reacted for a period of time at a stirring speed of 200 r / min, a reaction temperature of 60°C, and a reaction time of 4 h to obtain a primary product with an epoxy end group.

[0056] (iii) Grafting amino group reaction

[0057] 0.2 mol of triethylenetetramine was added to the product obtained in step (ii), and the mixture was heated under stirring for a period of time at a stirring speed of 200 r / min, a reaction temperature of 60° C., and a reaction time of 4 h to obtain a modifier having an amino group as an external group;

[0058] (iv) Modified graphene reaction

[0059] Add an appropriate amount of graphene powder to the product obtained in step (iii), heat it under stirring, react for a period of time, the stirring speed is 200r / min, the reaction temperature is 60°C, the reaction time is 4h, and the amphiphilic modified graphene is obtained by filtering and washing.

[0060] Example 4

[0061] (i) Drying of raw materials

[0062] Vacuum the polyetheramine and E51 at 50°C for 1 h and store them in a sealed bottle for later use.

[0063] (ii) Grafting epoxy group reaction

[0064] 0.1 mol of polyetheramine and 0.2 mol of E51 obtained in step (i) were heated under stirring conditions and reacted for a period of time at a stirring speed of 200 r / min, a reaction temperature of 60°C, and a reaction time of 4 h to obtain a primary product with an epoxy end group.

[0065] (iii) Grafting amino group reaction

[0066] 0.2 mol of ethylenediamine was added to the product obtained in step (ii), and the mixture was heated under stirring for a period of time at a stirring speed of 200 r / min, a reaction temperature of 60° C., and a reaction time of 4 h to obtain a modifier having an amino group as an external group;

[0067] (iv) Modified graphene reaction

[0068] Add an appropriate amount of graphene powder to the product obtained in step (iii), heat it under stirring, react for a period of time, the stirring speed is 200r / min, the reaction temperature is 60°C, the reaction time is 4h, and the amphiphilic modified graphene is obtained by filtering and washing.

[0069] Example 5

[0070] (i) Drying of raw materials

[0071] The polyetheramine and 1,4-butanediol diglycidyl ether were vacuumed at 50°C for 1 h and stored in a sealed bottle for later use.

[0072] (ii) Grafting epoxy group reaction

[0073] 0.1 mol of polyetheramine and 0.2 mol of 1,4-butanediol diglycidyl ether obtained in step (i) are heated under stirring conditions and reacted for a period of time at a stirring speed of 200-2000 r / min, a reaction temperature of 60°C, and a reaction time of 4 hours to obtain a primary product with an epoxy end group.

[0074] (iii) Grafting amino group reaction

[0075] 0.2 mol of ethylenediamine was added to the product obtained in step (ii), and the mixture was heated under stirring for a period of time at a stirring speed of 200 r / min, a reaction temperature of 60° C., and a reaction time of 4 h to obtain a modifier having an amino group as an external group;

[0076] (iv) Modified graphene reaction

[0077] Add an appropriate amount of graphene powder to the product obtained in step (iii), heat it under stirring, react for a period of time, the stirring speed is 200r / min, the reaction temperature is 60°C, the reaction time is 4h, and the amphiphilic modified graphene is obtained by filtering and washing.

[0078] Example 6

[0079] (i) Drying of raw materials

[0080] The polyetheramine and 1,4-butanediol diglycidyl ether were vacuumed at 50°C for 1 h and stored in a sealed bottle for later use.

[0081] (ii) Grafting epoxy group reaction

[0082] 0.1 mol of polyetheramine and 0.2 mol of 1,4-butanediol diglycidyl ether obtained in step (i) were heated under stirring conditions and reacted for a period of time at a stirring speed of 200 r / min, a reaction temperature of 60°C, and a reaction time of 4 h to obtain a primary product with an epoxy end group.

[0083] (iii) Grafting amino group reaction

[0084] 0.2 mol of triethylenetetramine was added to the product obtained in step (ii), and the mixture was heated under stirring for a period of time at a stirring speed of 200 r / min, a reaction temperature of 60° C., and a reaction time of 4 h to obtain a modifier having an amino group as an external group;

[0085] (iv) Modified graphene reaction

[0086] Add an appropriate amount of graphene powder to the product obtained in step (iii), heat it under stirring, react for a period of time, the stirring speed is 200r / min, the reaction temperature is 60°C, the reaction time is 4h, and the amphiphilic modified graphene is obtained by filtering and washing.

[0087] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A method for preparing amphiphilic modified graphene, characterized in that: The following steps are involved: (i) Grafting epoxy group reaction The ether compound containing hydroxyl or amino group is mixed with epoxy raw material, heated and stirred to react, and the primary product with epoxy end group is obtained; (ii) Grafting amino group reaction The primary product having an epoxy end group obtained in step (i) is mixed with a diamine, and the mixture is heated and stirred to react to obtain a graphene modifier having an amino end group; (iii) Modified graphene reaction The graphene modifier obtained in step (ii) is mixed with the graphene dispersion, and a ring-opening reaction occurs under heating and stirring conditions to obtain amphiphilic modified graphene.

2. The method for preparing amphiphilic modified graphene according to claim 1, wherein: The reaction materials of step (i) are vacuum-heated and dried before the reaction; the vacuum-heated drying temperature is 50° C. and the drying time is 1 h.

3. The method for preparing amphiphilic modified graphene according to claim 1, wherein: In the step (i), the molar ratio of the ether compound containing hydroxyl or amino group to the epoxy raw material is 1:2 to 3:

4.

4. The method for preparing amphiphilic modified graphene according to claim 1, wherein: The ether compound containing hydroxyl or amino group is polyetheramine or polyethylene glycol; the epoxy raw material is any one or more of E51, E44, 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether or 1,6-hexanediol diglycidyl ether.

5. The method for preparing amphiphilic modified graphene according to claim 1, wherein: The reaction starting materials of step (i) also include a catalyst; the catalyst is boron trifluoride etherate.

6. The method for preparing the amphiphilic modified graphene according to claim 5, wherein: The added mass of the catalyst is 0.1% to 0.5% of the total mass of the ether compound containing hydroxyl or amino group and the epoxy raw material.

7. The method for preparing amphiphilic modified graphene according to claim 1, wherein: The diamine is any one or more of ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine; the addition ratio of the diamine to the primary product having an epoxy end group is (2-2.5):

1.

8. The method for preparing amphiphilic modified graphene according to claim 1, wherein: The graphene dispersion is a graphene ethanol solution with a concentration of 1 mg / mL, and the mass ratio of the graphene modifier to the graphene dispersion is (2-5):

1.

9. The method for preparing amphiphilic modified graphene according to claim 1, wherein: The stirring rates of steps (i), (ii) and (iii) are all 200 r / min to 2000 r / min; the heating temperatures are all 60° C. to 90° C.; and the reaction times are all 4 h to 6 h.

10. An amphiphilic modified graphene, characterized in that: Prepared by the method according to any one of claims 1 to 9.

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