Self-repairing aminated graphene / MXene type curing cathode electrophoretic paint and preparation method thereof
By introducing amino and disulfide bonds between graphene oxide and MXene to form a dense covalent cross-linked network, an amino-graphene/MXene-type cured cathodic electrophoretic paint is developed, which solves the problems of insufficient protective performance and insufficient self-healing ability of existing electrophoretic paints and achieves high performance and self-healing coating effect.
Patent Information
- Application Number
- CN202511843926.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-09
- Publication Date
- 2026-01-23
AI Technical Summary
Existing cathodic electrophoretic paints have limited protective performance, making it difficult to meet increasingly demanding application requirements. Furthermore, they are prone to coating damage during use that cannot be self-repaired.
An amino-based graphene/MXene-type cured cathodic electrophoretic paint is used. By introducing amino groups and disulfide bonds between graphene oxide and MXene, crosslinking of graphene oxide and MXene is achieved, forming a dense covalent crosslinked network. The dynamic nature of the disulfide bonds is utilized to achieve self-healing.
It improves the mechanical properties and electrical conductivity of the coating, enhances the structural stability and electromagnetic shielding performance of the coating, and achieves self-repair through the rearrangement of chemical bonds when the coating is damaged, thereby improving the protective performance and service life.
Smart Images
Figure CN121379299A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the field of electrophoretic paint, and particularly relates to a self-repairing amino-graphene / MXene type cured cathodic electrophoretic paint and a preparation method thereof. BACKGROUND
[0002] Cathodic electrophoretic paint is an environmentally friendly coating with cationic water-soluble resin as the base material. Its coating process is essentially an electrochemical deposition: the workpiece acts as a cathode, and the cationic resin-pigment complex migrates to it in a direct current field and completes Faraday deposition to form a dense coating. Compared with traditional spraying, electrostatic spraying and dipping, it has the outstanding technical characteristics of high film density, excellent protection performance and good environmental compatibility, and has developed into a mainstream coating technology scheme for high protection demand scenarios in the industrial field. However, the cathodic electrophoretic paint on the market still has limited protection performance and other problems, which is difficult to meet the increasingly improved application requirements.
[0003] MXene is a kind of two-dimensional material with a graphite-like structure, which is composed of transition metal carbide, nitride or carbonitride. As a new type of material, MXene has ultra-high electrical conductivity and excellent mechanical properties, and its surface contains a large number of functional groups such as hydroxyl, oxygen and fluorine, so it has wide application prospects in the fields of energy storage, electromagnetic shielding and catalysis. SUMMARY
[0004] One of the purposes of the present application is to provide a self-repairing amino-graphene / MXene type cured cathodic electrophoretic paint, which comprises epoxy resin, cosolvent, water and amino-graphene / MXene containing disulfide bond, and the mass ratio of epoxy resin, cosolvent, water and amino-graphene / MXene containing disulfide bond is 90-110:2-5:100-150:5-10. The amino-graphene / MXene containing disulfide bond is prepared by the following steps: Step 1, mixing the DMF dispersion liquid of graphene oxide and the DMF dispersion liquid of MXene, ultrasonic, so that the graphene oxide and MXene are fully mixed in the DMF to obtain a graphene oxide / MXene mixed dispersion liquid; Step 2, adding 1,6-diisocyanate hexane disulfide and dibutyl tin dilaurate to the graphene oxide / MXene mixed dispersion liquid, and reacting under nitrogen atmosphere to obtain graphene oxide / MXene containing disulfide bond; Step 3, dissolving the graphene oxide / MXene containing disulfide bond in ethanol, and then adding a silane coupling agent to obtain amino-graphene / MXene containing disulfide bond.
[0005] Further, in step 1, the concentration of the DMF dispersion solution of graphene oxide is 0.5-10 g / L, the concentration of the DMF dispersion solution of MXene is 0.5-10 g / L, the mass ratio of the graphene oxide and MXene is 1-9:10, and the concentration of the graphene oxide / MXene mixed dispersion solution is 1-10 g / L.
[0006] Further, in step 1, the ultrasonic power is 700-2000 W, and the ultrasonic time is 0.5-2 h.
[0007] Further, in step 2, the mass ratio of 1,6-diisocyanate hexane disulfide and graphene oxide / MXene is 1-5:1, and the reaction conditions are 70-75℃ and 20-36 h.
[0008] Further, in step 3, the mass ratio of the silane coupling agent and the graphene oxide / MXene containing disulfide bond is 2-5:1, and the reaction conditions are 800-1000 rpm, 70-75℃, and 5-7 h.
[0009] Further, the silane coupling agent is one or a mixture of two or more of 3-aminopropyl trimethoxysilane (APTMS), 3-aminopropyl triethoxysilane (APTES), 3-aminopropyl(diethoxy)methylsilane, and N-(2-aminoethyl)-3-aminopropyl trimethoxysilane.
[0010] Further, the cosolvent is one or a mixture of two or more of propylene glycol methyl ether, ethylene glycol butyl ether, and dipropylene glycol butyl ether.
[0011] The second object of the present application is to provide a preparation method of the self-repairing amino-functionalized graphene / MXene type cured cathodic electrophoretic paint, which uniformly mixes epoxy resin, cosolvent, water, and amino-functionalized graphene / MXene containing disulfide bond to obtain the self-repairing amino-functionalized graphene / MXene type cured cathodic electrophoretic paint.
[0012] In one specific embodiment of the present application, the amino-functionalized modified graphene / MXene containing disulfide bond is dispersed in water by stirring and ultrasonic dispersion for 0.5-1 h, then the epoxy resin and the cosolvent are added respectively, and the electrophoretic film is obtained by electrophoresis and baking in an oven.
[0013] The present application has the following advantages: 1. The present application greatly improves the interfacial compatibility between the two-dimensional nanomaterial and the resin by introducing amino groups and disulfide bonds, so that the two-dimensional sheet structure of GO and MXene can be uniformly dispersed in the epoxy resin, and the amino groups and the epoxy resin can be crosslinked by ring-opening reaction, which improves the crosslinking density of the coating, makes the entire three-dimensional network structure more compact, and enhances the mechanical properties of the coating.
[0014] 2. The mutual interpenetration between graphene oxide and Mxene layers effectively prevents their respective aggregation. The present application can achieve cross-linking between graphene oxide and MXene through the introduction of amino groups and disulfide bonds, effectively "locking" GO and MXene nanosheets, inhibiting their swelling in water environment, and maintaining stable interlayer spacing, thereby significantly improving the structural stability and mechanical strength of the composite material.
[0015] 3. Covalent cross-linking generally does not sacrifice the excellent high conductivity of MXene itself while enhancing mechanical properties. The dense covalent cross-linking network instead provides a more efficient electron transport path, thereby maintaining or even improving the electrical conductivity of the composite material, making it have excellent electromagnetic shielding performance.
[0016] 4. The disulfide bond belongs to a dynamic covalent bond. With its introduction, when the coating produces microcracks due to scratching, the stress at the crack will cause the disulfide bond to break, but through temperature conditions, the adjacent disulfide bond can undergo an exchange reaction, allowing the chemical bond to rearrange in the network, thereby "healing" the crack and achieving self-repair. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 TEM image of MXene (Ti3C2T x ) of Example 1.
[0018] Figure 2 Photo of the self-repairing amino-functionalized graphene / MXene type cured cathodic electro-deposition paint film prepared in Example 1 after neutral salt spray test for 720h. DETAILED DESCRIPTION
[0019] The preferred embodiments of the present application will be described in detail below with reference to the examples. It should be understood that the following examples are given only to illustrate the present application and are not intended to limit the scope of the present application. Those skilled in the art can make various modifications and substitutions to the present application without departing from the spirit and principles of the present application.
[0020] The experimental methods used in the following examples are conventional methods unless otherwise specified.
[0021] The materials used in the following examples are all commercially available. The graphene oxide is from Jiangsu Xianfeng Nanometer Material Technology Co., Ltd., with the item number XFSG01; the MXene is from Jiangsu Xianfeng Nanometer Material Technology Co., Ltd., with the item number XFK01, purity 65-75wt%; the epoxy resin is purchased from Zhenxin Resin, model BECKOPOX EP 384w / 53w amp.
[0022] In the following examples, DMF is N,N-dimethylformamide. Example 1
[0023] Preparation of self-repairing aminated graphene / MXene type cured cathodic electrophoretic paint (1) Preparation of DMF mixed dispersion of graphene oxide / MXene: 1 g of graphene oxide powder was added to 500 mL of DMF, and ultrasonicated at 1000 W below 30°C for 1 h to obtain a 2 g / L graphene oxide DMF dispersion; 2 g of titanium carbide (Ti3C2T x ) MXene nanosheets were added to 1000 mL of DMF, and ultrasonicated at 1000 W below 30°C for 1 h to obtain a 2 g / L titanium carbide (Ti3C2T x ) MXene DMF dispersion; the two DMF dispersions were mixed and ultrasonicated at 1000 W below 30°C for another 0.5 h to obtain a 2 g / L graphene oxide / MXene mixed DMF dispersion.
[0024] (2) SS modified graphene oxide / MXene: 1000 mL of the graphene oxide / MXene mixed DMF solution was added with 2 g of 1,6-diisocyanate hexane dithioether and 0.01 g of dibutyltin dilaurate under the condition of 800 r / min, and heated to 70°C under nitrogen protection, and reacted for 30 h, and then cooled to room temperature, and centrifuged at 10000 rpm / min for 10 min, and the lower product was washed with DMF and water for 3 times respectively, and freeze-dried to obtain graphene oxide / MXene containing disulfide bonds (SS modified graphene oxide / MXene).
[0025] (3) Preparation of aminated graphene / MXene containing disulfide bonds: 0.75 g of SS modified graphene oxide / MXene was added to 500 mL of ethanol, and ultrasonicated at 1000 W for 1 h, and 1.5 g of 3-aminopropyltrimethoxysilane was added under the condition of 800 r / min at 30°C, and heated to 70°C, and reacted for 6 h, and then cooled to room temperature, and centrifuged at 10000 rpm / min for 10 min, and the lower product was washed with ethanol and water for 3 times respectively, and freeze-dried to obtain aminated graphene / MXene containing disulfide bonds.
[0026] (4) Preparation of self-repairing aminated graphene / MXene type cured cathodic electrophoretic paint and electrophoretic paint film: 0.75 g of aminated graphene / MXene containing disulfide bonds was added to 15 g of water and stirred and ultrasonicated for 0.5 h, and then 15 g of epoxy resin and 0.75 g of propylene glycol methyl ether were added and stirred, and an electrophoretic film was formed, and then baked in a 120°C oven for 1 h to obtain an electrophoretic paint film. Example 2
[0027] Preparation of self-repairing aminated graphene / MXene type cured cathodic electrophoretic paint Preparation of DMF mixed dispersion of graphene oxide / MXene: 2 g of graphene oxide powder was added to 500 mL of DMF, and ultrasonicated at 1000 W below 30°C for 1 h to obtain a 4 g / L graphene oxide DMF dispersion; 4 g of titanium carbide (Ti3C2T x ) MXene nanosheets was added to 1000 mL of DMF, and ultrasonicated at 1000 W below 30°C for 1 h to obtain a 4 g / L titanium carbide (Ti3C2T x ) MXene DMF dispersion; the two DMF dispersions were mixed and ultrasonicated at 1000 W below 30°C for another 0.5 h to obtain a 4 g / L graphene oxide / MXene mixed DMF dispersion.
[0028] (2) SS modified graphene oxide / MXene: 1000 mL of graphene oxide / MXene mixed DMF solution was taken, 6 g of 1,6-diisocyanate hexane dithioether and 0.02 g of dibutyltin dilaurate were added under the condition of 800 r / min, and nitrogen protection, heated to 75°C, reacted for 30 h, cooled to room temperature, centrifuged at 10000 rpm / min for 10 min, and the lower product was washed with DMF and water for 3 times respectively, and freeze-dried to prepare graphene oxide / MXene containing disulfide bond (SS modified graphene oxide / MXene).
[0029] (3) Preparation of graphene oxide / MXene containing disulfide bond: 0.6 g of SS modified graphene oxide / MXene was taken and added to 200 mL of ethanol, ultrasonicated at 1000 W for 2 h, 1.5 g of 3-aminopropyltrimethoxysilane was added under the condition of 30°C and 800 r / min, heated to 70°C, reacted for 6 h, cooled to room temperature, centrifuged at 10000 rpm / min for 10 min, and the lower product was washed with ethanol and water for 3 times respectively, and freeze-dried to obtain graphene oxide / MXene powder containing disulfide bond.
[0030] (4) Preparation of self-repairing amino-functionalized graphene oxide / MXene type cured cathodic electrophoretic paint and electrophoretic paint film: 0.5 g of graphene oxide / MXene powder containing disulfide bond was taken, stirred and ultrasonicated in 15 g of water for 0.5 h, then 10 g of epoxy resin and 0.2 g of propylene glycol methyl ether were added and continued to be stirred, and an electrophoretic film was formed, which was baked in an oven at 120°C for 1 h to obtain an electrophoretic paint film. Example 3
[0031] Preparation of self-repairing amino-functionalized graphene oxide / MXene type cured cathodic electrophoretic paint (1) Preparation of DMF mixed dispersion of graphene oxide / MXene: 1 g of graphene oxide powder was added to 2000 mL of DMF, and ultrasonicated at 1000 W below 30°C for 1 h to obtain a 0.5 g / L graphene oxide DMF dispersion; 1 g of titanium carbide (Ti3C2T x ) MXene nanosheets was added to 500 mL of DMF, and ultrasonicated at 1000 W below 30°C for 1 h to obtain a 2 g / L titanium carbide (Ti3C2T x ) MXene DMF dispersion; the two DMF dispersions were mixed and ultrasonicated at 1000 W below 30°C for 0.5 h to obtain a 0.8 g / L graphene oxide / MXene mixed DMF dispersion.
[0032] (2) SS modified graphene oxide / MXene: 2500 mL of the graphene oxide / MXene mixed DMF solution was added with 4 g of 1,6-diisocyanate hexane dithioether and 0.01 g of dibutyltin dilaurate under the condition of 800 r / min, and heated to 72°C under nitrogen protection, and reacted for 36 h, and cooled to room temperature, and centrifuged at 10000 rpm / min for 10 min, and the lower product was washed with DMF and water for 3 times respectively, and freeze-dried to obtain the graphene oxide / MXene containing disulfide bonds (SS modified graphene oxide / MXene).
[0033] (3) Preparation of graphene oxide / MXene containing disulfide bonds: 1.1 g of the SS modified graphene oxide / MXene was added to 700 mL of ethanol, and ultrasonicated at 1000 W for 2 h, and 2.2 g of 3-aminopropyltrimethoxysilane was added under the condition of 800 r / min at 30°C, and heated to 75°C, and reacted for 5 h, and cooled to room temperature, and centrifuged at 10000 rpm / min for 10 min, and the lower product was washed with ethanol and water for 3 times respectively, and freeze-dried to obtain the graphene oxide / MXene containing disulfide bonds powder.
[0034] (4) Preparation of self-repairing amino-functionalized graphene oxide / MXene type cured cathodic electrophoretic paint and electrophoretic paint film: 1 g of the graphene oxide / MXene containing disulfide bonds powder was stirred and ultrasonicated in 20 g of water for 0.5 h, and then 20 g of epoxy resin and 0.1 g of propylene glycol methyl ether were added for continuous stirring, and an electrophoretic film was formed, and the film was baked in an oven at 150°C for 0.5 h to obtain an electrophoretic paint film. Example 4
[0035] Preparation of self-repairing amino-functionalized graphene oxide / MXene type cured cathodic electrophoretic paint Preparation of DMF mixed dispersion of graphene oxide / MXene: 3 g of graphene oxide powder was added to 1000 mL of DMF, and ultrasonicated at 1000 W below 30°C for 1 h to obtain a 3 g / L graphene oxide DMF dispersion; 4 g of titanium carbide (Ti3C2T x ) MXene nanosheets were added to 1000 mL of DMF, and ultrasonicated at 1000 W below 30°C for 1 h to obtain a 4 g / L titanium carbide (Ti3C2T x ) MXene DMF dispersion; the two DMF dispersions were mixed and ultrasonicated at 1000 W below 30°C for another 0.5 h to obtain a graphene oxide / MXene mixed DMF dispersion with a concentration of 3.5 g / L.
[0036] (2) SS modified graphene oxide / MXene: 1000 mL of graphene oxide / MXene mixed DMF solution was taken, 8 g of 1,6-diisocyanate hexane disulfide and 0.02 g of dibutyltin dilaurate were added under the condition of 800 r / min, and heated to 75°C under nitrogen protection, and reacted for 20 h. After cooling to room temperature, centrifugation was performed at 10000 rpm / min for 10 min, and the lower product was washed with DMF and water for 3 times respectively, and freeze-dried to obtain graphene oxide / MXene containing disulfide bond (SS modified graphene oxide / MXene).
[0037] (3) Preparation of graphene oxide / MXene containing disulfide bond: 1.5 g of SS modified graphene oxide / MXene was taken and added to 600 mL of ethanol, and ultrasonicated at 2000 W for 1 h. 6 g of 3-aminopropyltrimethoxysilane was added under the condition of 800 r / min at 30°C, and heated to 72°C and reacted for 5 h. After cooling to room temperature, centrifugation was performed at 10000 rpm / min for 10 min, and the lower product was washed with ethanol and water for 3 times respectively, and freeze-dried to obtain graphene oxide / MXene containing disulfide bond powder.
[0038] (4) Preparation of self-repairing amino-functionalized graphene oxide / MXene type cured cathodic electrophoretic paint and electrophoretic paint film: 1 g of graphene oxide / MXene containing disulfide bond powder was taken, and ultrasonicated in 15 g of water for 1 h, then 10 g of epoxy resin and 0.5 g of propylene glycol methyl ether were added and stirred, and an electrophoretic film was formed. The electrophoretic paint film was obtained by baking in an oven at 140°C for 0.5 h. Example 5
[0039] Preparation of self-repairing amino-functionalized graphene oxide / MXene type cured cathodic electrophoretic paint (1) Preparation of DMF mixed dispersion of graphene oxide / MXene: 1.35 g of graphene oxide powder was added to 500 mL of DMF, and ultrasonic treatment was performed at 1000 W below 30°C for 1 h to obtain a 2.7 g / L graphene oxide DMF dispersion. 1.5 g of titanium carbide (Ti3C2T x ) MXene nanosheet was added to 200 mL of DMF, and ultrasonic treatment was performed at 1000 W below 30°C for 1 h to obtain a 7.5 g / L titanium carbide (Ti3C2T x ) MXene DMF dispersion. The two DMF dispersions were mixed and ultrasonic treatment was continued at 1000 W below 30°C for 0.5 h to obtain a graphene oxide / MXene mixed DMF dispersion with a concentration of 4.07 g / L.
[0040] (2) SS modified graphene oxide / MXene: 700 mL of graphene oxide / MXene mixed ethanol solution was taken, 8 g of 1,6-diisocyanate hexane dithioether and 0.01 g of dibutyltin dilaurate were added under the condition of 800 r / min, and the mixture was heated to 70°C under nitrogen protection and reacted for 36 h. After cooling to room temperature, centrifugation was performed at 10000 rpm / min for 10 min, and the lower layer product was washed with DMF and water for 3 times respectively, and then freeze-dried to obtain graphene oxide / MXene containing disulfide bond (SS modified graphene oxide / MXene).
[0041] (3) Preparation of graphene oxide / MXene containing disulfide bond: 2.8 g of SS modified graphene oxide / MXene was taken and added to 700 mL of ethanol, and ultrasonic treatment was performed at 2000 W for 2 h. 11.4 g of 3-aminopropyltrimethoxysilane was added under the condition of 1000 r / min at 30°C, and the mixture was heated to 72°C and reacted for 6 h. After cooling to room temperature, centrifugation was performed at 10000 rpm / min for 10 min, and the lower layer product was washed with ethanol and water for 3 times respectively, and then freeze-dried to obtain graphene oxide / MXene containing disulfide bond powder.
[0042] (5) Preparation of self-repairing amino-functionalized graphene oxide / MXene type cured cathodic electrophoretic paint and electrophoretic paint film: 2 g of graphene oxide / MXene containing disulfide bond powder was taken, and ultrasonic treatment was performed in 40 g of water for 1 h, then 50 g of epoxy resin and 1 g of propylene glycol methyl ether were added and continued to be stirred, and an electrophoretic film was formed. The electrophoretic film was obtained by baking in an oven at 130°C for 0.5 h. Comparative Example 1
[0043] Preparation of graphene oxide / MXene modified cathodic electrophoretic paint (1) Preparation of graphene oxide / MXene ethanol mixed dispersion: 0.5 g of graphene oxide powder was added to 500 mL of ethanol, and ultrasonic treatment was performed at 1000 W below 30°C for 1 h to obtain a 1 g / L graphene oxide ethanol dispersion; 1 g of titanium carbide (Ti3C2T x ) MXene nanosheet was added to 500 mL of ethanol, and ultrasonic treatment was performed at 1000 W below 30°C for 1 h to obtain a 2 g / L titanium carbide (Ti3C2T x ) MXene ethanol dispersion; the two ethanol dispersions were mixed and ultrasonic treatment was continued at 1000 W below 30°C for 0.5 h to obtain a graphene oxide / MXene mixed ethanol dispersion with a concentration of 1.5 g / L.
[0044] (2) Preparation of graphene oxide / MXene mixed powder: 500 mL of graphene oxide / MXene mixed ethanol dispersion was centrifuged at 10000 rpm / min for 10 min, and the lower layer product was washed with ethanol and water for 3 times respectively, and freeze-dried to obtain graphene oxide / MXene mixed powder.
[0045] (3) Preparation of graphene oxide / MXene modified cathode electrophoretic paint and electrophoretic paint film: 0.75 g of graphene oxide / MXene mixed powder was stirred and ultrasonic treated in 15 g of water for 0.5 h, then 15 g of epoxy resin and 0.75 g of propylene glycol methyl ether were added and continued to be stirred, and an electrophoretic film was formed, which was baked in a 120°C oven for 1 h to obtain an electrophoretic paint film. Comparative Example 2
[0046] Preparation of MXene type solidified cathode electrophoretic paint (1) Preparation of MXene ethanol dispersion: 1 g of titanium carbide (Ti3C2T x ) MXene nanosheet was added to 500 mL of ethanol, and ultrasonic treatment was performed at 1000 W below 30°C for 1 h to obtain a 2 g / L titanium carbide (Ti3C2T x ) MXene ethanol dispersion.
[0047] (2) Preparation of aminated modified MXene: 500 mL of MXene ethanol dispersion was added to 6 g of 3-aminopropyltrimethoxysilane at 30°C and 800 r / min, heated to 72°C, and reacted for 6 h, cooled to room temperature, centrifuged at 10000 rpm / min for 10 min, and the lower layer product was washed with ethanol and water for 3 times respectively, and freeze-dried to obtain aminated modified MXene powder.
[0048] (3) Preparation of MXene type solidified cathode electrophoretic paint and electrophoretic paint film: take 0.75 g of amino-modified MXene powder, stir and ultrasonic in 15 g of water for 0.5 h, then add 15 g of epoxy resin and 0.75 g of propylene glycol methyl ether and continue to stir, electrophoretic film forming, baking in 120℃ oven for 1 h, to get electrophoretic paint film. Comparative Example 3
[0049] Preparation of graphene oxide / MXene type solidified cathode electrophoretic paint (1) Preparation of ethanol mixed dispersion of graphene oxide / MXene: add 1.35 g of graphene oxide powder into 500 mL of ethanol, ultrasonic at 2000 W below 30℃ for 2 h, to get 2.7 g / L of graphene oxide ethanol dispersion; add 1.5 g of titanium carbide (Ti3C2T x ) MXene nanosheet into 200 mL of ethanol, ultrasonic at 2000 W below 30℃ for 2 h, to get 7.5 g / L of titanium carbide (Ti3C2T x ) MXene ethanol dispersion; mix the two ethanol dispersions and continue to ultrasonic at 2000 W below 30℃ for 1 h, to get about 4.07 g / L of graphene oxide / MXene mixed ethanol dispersion.
[0050] (3) Preparation of amino-modified graphene / MXene: take 700 mL of graphene oxide / MXene mixed ethanol dispersion, add 11.4 g of 3-aminopropyltrimethoxysilane at 30℃ and 1000 r / min, heat to 72℃, react for 6 h, cool to room temperature, centrifuge at 10000 rpm / min for 10 min, wash the lower product with ethanol and water respectively for 3 times, freeze-dry, to get amino-modified graphene / MXene powder.
[0051] (4) Preparation of amino-modified graphene / MXene type solidified cathode electrophoretic paint and electrophoretic paint film: take 2 g of amino-modified graphene / MXene powder, stir and ultrasonic in 40 g of water for 1 h, then add 50 g of epoxy resin and 1 g of propylene glycol methyl ether and continue to stir, electrophoretic film forming, baking in 130℃ oven for 0.5 h, to get electrophoretic paint film.
[0052] The self-repairing aminated graphene / MXene type cured cathodic electrophoretic paint prepared in Examples 1-5 and the electrophoretic paint prepared in Comparative Examples 1-3 were tested. The hardness and adhesion of the paint film were tested according to GB / T 6739-2022 and GB / T 1720-2020, respectively. It can be seen that the hardness of the paint film of the self-repairing aminated graphene / MXene type cured cathodic electrophoretic paint prepared in Examples 1-5 reaches 5H, and the adhesion reaches level 1. In Comparative Example 1, the modified electrophoretic paint is simply added with graphene oxide / MXene, and the resin does not reach a certain crosslinking degree, so the hardness and adhesion of the coating are low. In Comparative Example 2, the MXene type cured cathodic electrophoretic paint film is prepared, and although the aminated MXene realizes the curing of the epoxy resin, there is a certain degree of agglomeration between the MXene layers, which cannot realize the mutual interpenetration between the graphene oxide and the MXene layers as in the examples, and prevent their own agglomeration, so the hardness and adhesion of the paint film are slightly worse. In Comparative Example 3, the hardness and adhesion reach the level of Examples 1-5.
[0053] The neutral salt spray test (720h) of the electrophoretic paint film was carried out according to GB / T 10125-2021, Figure 2 The photo of Example 1 after 720h of neutral salt spray test. As can be seen from Table 1, the electrophoretic paint film prepared in Examples 1-5 has excellent corrosion resistance after 720h of neutral salt spray test. In Comparative Example 1, the graphene oxide / MXene powder is not modified, which leads to poor crosslinking degree of the paint film, and the neutral salt spray test is unqualified. In Comparative Example 2, the MXene is modified by amination, and the paint film passes the neutral salt spray test. In Comparative Example 3, the paint film passes the neutral salt spray test.
[0054] Table 1 Performance comparison of electrophoretic paint films prepared in Examples 1-5 and Comparative Examples 1-3
[0055] The shielding effectiveness of the electrophoretic paint film prepared in Examples 1-5 and Comparative Examples 1-3 was tested according to GB / T 25471-2010. It can be seen that the electromagnetic shielding effectiveness of the electrophoretic paint film prepared in Examples 1-5 is above 40 dB at different frequencies, and the shielding effectiveness is excellent. On the one hand, the amino-oxidized graphene / MXene itself has excellent conductivity, and the covalent crosslinking enhances the mechanical properties without sacrificing the excellent high conductivity of MXene itself. The dense covalent crosslinking network provides a more efficient electron transport path, thereby maintaining or even improving the electrical conductivity of the composite material, so that it has excellent electromagnetic shielding performance. On the other hand, the interpenetration between the graphene oxide and the MXene layers makes them well dispersed in the resin, ensuring the realization of high conductivity. The electromagnetic shielding effectiveness of the electrophoretic paint film prepared in Comparative Examples 1-2 is below 40 dB at different frequencies; the electromagnetic shielding effectiveness of the electrophoretic paint film prepared in Comparative Example 3 is also above 40 dB at different frequencies.
[0056] Table 2 Comparison of electromagnetic shielding effectiveness of electrophoretic paint films prepared in Examples 1-5 and Comparative Examples 1-3
[0057] Self-repairing performance evaluation: The electromagnetic shielding effectiveness at 600 MHz and 1 GHz before and after damage and repair was tested, and the repair efficiency was calculated. The damage was simulated by scratch damage in actual use by using a knife or scratch tester to make one or more scratches on the surface of the coating. The repair was carried out at 60°C for 6 h.
[0058] Table 3 Comparison of electromagnetic shielding effectiveness of electrophoretic paint films prepared in Examples 1-5 and Comparative Examples 1-3 before and after repair at 600 MHz
[0059] Table 4 Comparison of electromagnetic shielding effectiveness of electrophoretic paint films prepared in Examples 1-5 and Comparative Examples 1-3 before and after repair at 1 GHz
[0060] From the above results, it can be seen that the self-repairing efficiency (η) of the coating in Examples 1-5 is above 85%, while the self-repairing efficiency (η) of the coating in Comparative Examples 1-3 is less than 40%. This is because the disulfide bond in the coating can undergo exchange reaction at 60°C, so that the chemical bond is rearranged in the network, thereby "healing" the crack and realizing self-repairing.
Claims
1. A self-healing aminated graphene / MXene-type curable cathodic electrophoretic paint, characterized in that, The product includes epoxy resin, cosolvent, water, and disulfide-bonded aminated graphene / MXene, with a mass ratio of epoxy resin, cosolvent, water, and disulfide-bonded aminated modified graphene / MXene of 90-110:2-5:100-150:5-10. The disulfide-bonded amino-graphene / MXene was prepared using the following steps: Step 1: Mix the DMF dispersion of graphene oxide and the DMF dispersion of MXene, and sonicate to ensure that the graphene oxide and MXene are fully mixed in the DMF to obtain a graphene oxide / MXene mixed dispersion. Step 2: Add 1,6-diisocyanate hexane disulfide and dibutyltin dilaurate to the graphene oxide / MXene mixed dispersion, and react under a nitrogen atmosphere to obtain graphene oxide / MXene containing disulfide bonds. Step 3: Dissolve graphene oxide / MXene containing disulfide bonds in ethanol, and then add a silane coupling agent to react and obtain amino graphene / MXene containing disulfide bonds.
2. The self-healing aminated graphene / MXene-type cured cathodic electrophoretic paint according to claim 1, characterized in that, In step 1, the concentration of the DMF dispersion of graphene oxide is 0.5-10 g / L, the concentration of the DMF dispersion of MXene is 0.5-10 g / L, the mass ratio of graphene oxide to MXene is 1-9:10, and the concentration of the graphene oxide / MXene mixed dispersion is 1-10 g / L.
3. The self-healing aminated graphene / MXene-type cured cathodic electrophoretic paint according to claim 1, characterized in that, In step 1, the ultrasonic power is 700-2000 W and the ultrasonic time is 0.5-2 h.
4. The self-healing aminated graphene / MXene-type cured cathodic electrophoretic paint according to claim 1, characterized in that, In step 2, the mass ratio of 1,6-diisocyanate hexane disulfide to graphene oxide / MXene is 1-5:1, and the reaction conditions are 70-75℃ for 20-36 h.
5. The self-healing aminated graphene / MXene-type cured cathodic electrophoretic paint according to claim 1, characterized in that, In step 3, the mass ratio of silane coupling agent to disulfide-bonded graphene oxide / MXene is 2-5:1; the reaction conditions are 800-1000 rpm, 70-75℃, and 5-7h.
6. The self-healing aminated graphene / MXene-type cured cathodic electrophoretic paint according to claim 1, characterized in that, The silane coupling agent is one or a mixture of two or more of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyl(diethoxy)methylsilane, and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.
7. The self-healing aminated graphene / MXene-type cured cathodic electrophoretic paint according to claim 1, characterized in that, The co-solvent is one or a mixture of two or more of propylene glycol methyl ether, ethylene glycol butyl ether, and dipropylene glycol butyl ether.
8. The method for preparing the self-healing aminated graphene / MXene-type cured cathodic electrophoretic paint according to any one of claims 1-7, characterized in that, A self-healing aminated graphene / MXene-type cured cathodic electrophoretic paint was prepared by mixing epoxy resin, co-solvent, water and disulfide-bonded amino-graphene / MXene evenly.