Preparation method of CeO2-GO hybrid material / epoxy resin composite anticorrosive coating

Abstract

The invention discloses a preparation method of a CeO2-GO hybrid material / epoxy resin composite anticorrosive coating, and the method comprises the following steps: carrying out covalent chemical modification on the surface of GO by using 3-aminopropyltriethoxysilane ((3-aminopropyltriethoxysilane, APTS) to obtain amino functionalized GO; the preparation method comprises the following steps: under the catalysis of acetic acid, carrying out surface modification on cerium dioxide nano particles by using 3-glycidyl ether oxypropyl trimethoxy silane (3-Glycidyloxyphenyltrimethoxysilane, GPTS), so as to obtain the epoxy group functionalized CeO2. And anchoring CeO2 nanoparticles on the surface of GO through a ring-opening reaction between the amino group and the epoxy group to obtain the CeO2-GO hybrid material. The prepared CeO2-GO hybrid material is added into an epoxy resin matrix, and the corrosion resistance of an obtained epoxy resin coating is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of polymer composite materials, and relates to a CeO 2 - Preparation method of GO hybrid material / epoxy resin composite anti-corrosion coating. Background Art

[0002] Cerium dioxide (Ceric dioxide, CeO 2 ) nanoparticles have attracted wide attention due to their unique catalytic, electrical and optical properties, and can be used as polishing materials, catalysts, UV absorbers, fuel cell electrolytes, automobile exhaust absorbers, electronic ceramics and lubricant additives. In addition, CeO 2 It can also be used as a cathode inhibitor, using its free Ce 3+ and Ce 4+ Ion auto-capture -OH to form Ce(OH) 3 and Ce(OH) 4 Passivation film protects the metal substrate material. Studies have shown that:

[0003] (1) A polyimine functionalized modified graphene oxide hybrid epoxy resin composite coating was prepared by electrophoretic deposition technology, and parallel-arranged GO was constructed in the coating, which has high-performance friction and wear performance. Experimental and molecular dynamics results show that the addition of parallel-aligned GO to the epoxy coating can significantly reduce the wear rate of the coating, up to 71%. Compared with pure EP coating, its Young's modulus, shear modulus and bulk modulus increased by 70%, 36% and 65%, respectively. The improvement of the mechanical and tribological properties of the composite coating is mainly attributed to the strong interaction between the functionalized GO and the epoxy resin matrix, and the effective barrier effect produced by the parallel-arranged functionalized GO. The parallel-arranged GO can effectively prevent the cracking and peeling of the coating, forming a friction protection film with high load-bearing capacity and wear resistance. (He Y, Fan X, Huang Y, et al. Experimental and theoretical evaluations on the parallel-aligned grapheneoxide hybrid epoxy composite coating toward wear resistance[J]. Carbon, 2024, 217: 118629.)

[0004] (2) Nano-Ti was functionalized with 3-aminopropyltriethoxysilane (APTS) to obtain f-Ti, and then the -NH 2Graphene oxide-titanium (GO-Ti) composites were prepared by anchoring nano-Ti particles on GO flakes through the ring-opening reaction between nano-Ti and -COC on the surface of GO. 1wt% GO, nano-Ti and GO-Ti were dispersed in epoxy resin to prepare the corresponding coating samples. The results showed that nano-Ti particles were successfully loaded on the surface of GO through chemical bonding, making the dispersion of GO-Ti composites in epoxy resin better than GO. Compared with nano-Ti and GO, at the same addition amount, GO-Ti composites showed significant advantages in improving the corrosion resistance of epoxy coatings, which was due to their excellent dispersibility, inherent corrosion resistance and flaky structure. Among the composites with different ratios, GO-Ti (2:1) material had the best dispersibility and corrosion resistance. In addition, GO-Ti composites also greatly improved the wear resistance of the coating. (Yuan H, Qi F, Zhao N, et al. Graphene Oxide Decorated with TitaniumNanoparticles to Reinforce the Anti-Corrosion Performance of Epoxy Coating[J]. Coatings, 2020,10(2):129.)

[0005] (3) CeO was prepared by a one-pot hydrothermal method using cerium nitrate hexahydrate as a precursor. 2 -GO hybrid materials. The cerium oxide nanoparticles can eliminate the agglomeration of GO to a certain extent, and can prepare CeO with good anti-corrosion performance. 2 The CeO-GO / EP coating was characterized by optical microscopy (OM), open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), Mott-Schottky curve and Tafel curve. 2 -State evolution of GO / EP coating in simulated seawater solution with different concentrations (20%, 40%, 60%), and CeO 2 -GO / EP and corrosion inhibitors. The results show that CeO 2 -GO / EP coating has good corrosion resistance in simulated seawater environment. (Liu X, Liu R, Li T, et al. Research on the Anticorrosion Properties of CeO2-GO / EP Nanocomposite Coating in Simulated Sea Water[J]. Polymers (Basel), 2021, 13(13): 2072.)

[0006] (4) Ultrafine cerium oxide quantum dots were in situ grown on the GO surface by a one-pot hydrothermal method to obtain cerium oxide quantum dot-modified graphene oxide (CeO 2 -QDs-GO) composites. CeO on the surface of GO 2 The quantum dots effectively increased the interlayer spacing of GO nanosheets, thereby reducing the number of layers. The prepared CeO 2 The corrosion inhibition performance of the -QDs-GO / EP coating was explored. The results showed that in the scratched sample, the maximum R ct 45080Ω·cm 2 The overall results show that CeO 2 -QDs-modified GO nanosheets exhibit excellent anticorrosion properties in epoxy coatings, CeO 2 -QDs enhance the corrosion resistance of the coating. (Shahini MH, Mousavi M, Masoud Arabi A, et al. Ce-oxide quantum dots decorated graphene oxide (CeO-QDs-GO) nano-platforms synthesis and application in epoxy matrix for efficient anti-corrosion ability [J]. Journal of Industrial and Engineering Chemistry, 2021, 101: 51-65.) According to previous research results, the addition of CeO 2 It has many benefits to the anti-corrosion performance of the coating, which lays a good research foundation for this invention.

[0007] Epoxy resin has good chemical corrosion resistance, wear resistance and high adhesion. Using epoxy resin coating as a physical barrier to isolate metal coating from the external environment is one of the most commonly used surface coating protection technologies. As a matter of course, the durability of the coating in actual production applications is very important. During the curing process of epoxy resin coating, due to the volatilization of the solvent in the system, a large number of micropores and microcracks remain inside the epoxy resin coating after film formation, which seriously limits the further application of epoxy resin coating. (Li H, Zhang QH, Meng XZ, et al. A novel cerium organic network modified graphene oxide prepared multifunctional waterborne epoxy-based coating with excellent mechanical and passive / active anti-corrosion properties [J]. Chemical Engineering Journal, 2023, 465: 142997.); Based on the above content, the present invention proposes a CeO 2 Preparation method of GO hybrid material / epoxy resin composite anti-corrosion coating Summary of the invention

[0008] The present invention aims to provide a CeO 2 -The preparation method of GO hybrid material / epoxy resin composite anti-corrosion coating solves the problems raised in the background technology. Due to the strong van der Waals force of GO, it is difficult to disperse it evenly in the epoxy resin matrix. At the same time, due to its high surface energy, its interface compatibility is poor and it is easy to agglomerate, which seriously limits its application in actual production and also limits its future development. The present invention overcomes the shortcomings of poor durability of traditional graphene coatings by introducing cerium dioxide, and the anti-corrosion performance of the coating is significantly improved.

[0009] To achieve the above purpose, the present invention adopts the following technical solution:

[0010] A CeO 2 - A method for preparing a GO hybrid material / epoxy resin composite anti-corrosion coating, comprising the following steps:

[0011] (1) Preparation of graphene oxide (GO) dispersion: Graphene oxide (GO) was prepared according to the improved Hummer method. Flake graphite (C), sodium nitrate (NaNO) were added to a three-necked beaker. 3 ) and concentrated sulfuric acid (H 2 SO 4 ) was stirred in an ice-water bath to react; then potassium permanganate (KMnO4 ) continue to stir the reaction; then raise the water bath temperature and continue to stir the reaction; add deionized water, continue to raise the water bath temperature, and continue to stir the reaction magnetically; add hydrogen peroxide (H 2 O 2 ) solution, and continue stirring until no obvious bubbles are generated. The reaction mixture is centrifuged to obtain a lower layer of graphene oxide (GO) colloid; the lower layer of graphene oxide (GO) colloid is repeatedly washed with dilute hydrochloric acid (HCl) solution and deionized water and centrifuged until the pH value of the upper clear liquid is neutral; the washed graphene oxide (GO) colloid is evenly dispersed in deionized water to obtain a graphene oxide (GO) dispersion.

[0012] (2) Cerium dioxide-graphene oxide (CeO 2 Preparation of hybrid materials:

[0013] 1. Take nano cerium dioxide (CeO 2 ), acetic acid (CH 3 COOH), anhydrous ethanol (C 2 H 6 O) and deionized water were added to a three-necked flask and ultrasonically dispersed to prepare liquid A; γ-glycidyloxypropyltrimethoxysilane (GPTS), anhydrous ethanol (C 2 H 6 O) and deionized water were added to a beaker and ultrasonically dispersed to prepare liquid B; liquid B was dropped into liquid A and refluxed under magnetic stirring in an oil bath to obtain a uniform turbid milky white liquid; the mixture was filtered through a microporous filter membrane and filtered with ethanol (C 2 H 6 O) and deionized water for multiple washings to obtain functionalized nano-cerium dioxide (f-CeO 2 ), and dried in a vacuum dryer.

[0014] 2. Take the graphene oxide (GO) dispersion and add it to a three-necked flask for later use; take anhydrous ethanol (C 2 H 6 The invention discloses a method for preparing a functionalized graphene oxide (f-GO) by adding 2-nitropropene oxide (PTO) and γ-aminopropyltriethoxysilane (APTS) into a three-necked flask, and ultrasonically dispersing the mixture to prepare liquid C; slowly dropping the liquid C into a graphene oxide (GO) dispersion, and reflux reacting by magnetic stirring in an oil bath, and cooling the mixture to room temperature to obtain a mixture liquid with a precipitate; filtering the mixture with a microporous filter membrane, and washing the mixture with ethanol and deionized water for multiple times to obtain functionalized graphene oxide (f-GO), and drying the mixture in a vacuum drying oven.

[0015] 3. Take functionalized nano-cerium dioxide (f-CeO 2), functionalized graphene oxide (f-GO) and N,N-dimethylformamide (DMF) were added to a three-necked flask, ultrasonically dispersed to make them uniformly mixed, and magnetically stirred under an oil bath to reflux the reaction to obtain a uniform turbid mixture liquid; filtered with a microporous filter membrane and washed with ethanol (C 2 H 6 O) and deionized water for multiple washings to obtain cerium dioxide-graphene oxide (CeO 2 -GO) hybrid material was placed in a vacuum dryer at 60 °C for 12 h.

[0016] (3) Cerium dioxide-graphene oxide hybrid material / epoxy resin (CeO 2 Preparation of GO / EP composite coating: Q235 steel plate was selected as the substrate of epoxy resin (EP) composite coating. First, the surface of Q235 steel plate was polished with sandpaper and acetone (C 3 H 6 O) and anhydrous ethanol (C 2 H 6 O) to remove excess grease from the steel plate surface. 2 -GO) (0.50wt%) was ultrasonically dispersed in anhydrous ethanol (C 2 H 6 O), then add epoxy resin (EP), after magnetic stirring, add curing agent and continue stirring, and remove anhydrous ethanol (C 2 H 6 O) and then evenly sprayed on a Q235 steel plate, cured at room temperature, and then cured at a specific temperature to obtain a uniform 0.50wt% cerium dioxide-graphene oxide hybrid material / epoxy resin (CeO 2 -GO / EP) composite coating. In order to explore the 2 The effect of the amount of cerium dioxide-graphene oxide (CeO-GO) hybrid material in epoxy resin (EP) coating on its anti-corrosion performance was studied. 1.00wt%, 1.50wt% and 2.00wt% cerium dioxide-graphene oxide hybrid material / epoxy resin (CeO 2 For comparison, 0.50 wt% functionalized graphene oxide / epoxy resin (f-GO / EP) composite coating and pure epoxy resin (EP) coating were prepared according to the same preparation process.

[0017] Preferably, the step (1) of adding flake graphite (C), sodium nitrate (NaNO 3 ) is the mass ratio of flake graphite (C): sodium nitrate (NaNO 3 )=2~4:1~2, concentrated sulfuric acid (H 2SO 4 ) is required to be in excess. At the same time, the reaction needs to be stirred in an ice-water bath at 0-5°C for 2 hours; then, potassium permanganate (KMnO 4 ) is added in an amount of 6 to 9 g, and the reaction is stirred for 5 h; potassium permanganate (KMnO 4 ), the water bath temperature was raised to 45°C, and the reaction was continued with stirring for 30 min; at the same time, 100 ml of deionized water was added, the water bath temperature was raised to 95°C, and the reaction was continued with magnetic stirring for 30 min; then, 10 ml of hydrogen peroxide (H 2 O 2 ) solution and continue stirring until no obvious bubbles are generated.

[0018] Preferably, the addition of nano-cerium dioxide (CeO 2 The molar ratio of nano-cerium dioxide (CeO 2 ):γ-glycidyloxypropyltrimethoxysilane (GPTS) = 1:1~2, where acetic acid in liquid A and anhydrous ethanol (C 2 H 6 Liquid B needs to be slowly dripped into liquid A, and refluxed under magnetic stirring in an oil bath at 65°C for 6 hours; after obtaining the final product, it is placed in a vacuum dryer and dried at 60°C for 12 hours.

[0019] Preferably, the molar ratio of the added graphene oxide (GO) dispersion and γ-aminopropyltriethoxysilane (APTS) in step (2) is graphene oxide (GO) dispersion: γ-aminopropyltriethoxysilane (APTS) = 1:6-8, anhydrous ethanol (C 2 H 6 O) is in excess and ultrasonically dispersed for 10 minutes; the successfully prepared C solution is slowly dripped into the graphene oxide (GO) dispersion, and refluxed under magnetic stirring in a 65°C oil bath for 4 hours, and then cooled to room temperature to obtain a mixture liquid with a precipitate; after obtaining the final product, it is placed in a vacuum dryer and dried at 60°C for 12 hours.

[0020] Preferably, the functionalized nano-cerium dioxide (f-CeO 2 ) to functionalized graphene oxide (f-GO) is f-CeO 2 :f-GO=1:1~2, N,N-dimethylformamide (DMF) needs to be in excess, ultrasonic dispersion needs 1 hour, after mixing evenly, magnetic stirring reflux reaction is carried out in a 110°C oil bath for 12 hours to obtain a uniform turbid mixture liquid; after obtaining the final product, it is placed in a vacuum dryer at 60°C for 12 hours.

[0021] Preferably, the size of the Q235 steel plate in step (3) is 40 mm × 20 mm × 1 mm, and the Q235 steel plate is polished using 500-mesh and 1000-mesh sandpapers respectively; in the subsequent operation, cerium dioxide-graphene oxide (CeO 2 -GO) (0.50wt%) has a mass of 45-55mg, anhydrous ethanol (C 2 H 6 O) needs to be in excess; at the same time, after adding the epoxy resin (EP), magnetic stirring is required for 30 minutes, and after adding the curing agent, stirring is continued for 15 minutes; the curing process is cured at room temperature for 24 hours, and then it needs to be cured at a specific temperature of 60°C for 12 hours.

[0022] A cerium dioxide-graphene oxide hybrid material / epoxy resin composite anti-corrosion coating prepared according to the method.

[0023] Compared with the prior art, the present invention provides a CeO 2 -The preparation method of GO hybrid material / epoxy resin composite anti-corrosion coating has the following beneficial effects:

[0024] The present invention innovatively designs a cerium dioxide-graphene oxide hybrid material / epoxy resin composite anti-corrosion coating, uses APTS to covalently chemically modify the GO surface to obtain amino-functionalized GO; under the catalysis of acetic acid, GPTS is used to modify CeO 2 Nanoparticles were surface modified to obtain epoxy functionalized CeO 2 (f-CeO 2 ). Through the ring-opening reaction between amino and epoxy groups, CeO 2 Nanoparticles are anchored on the surface of GO to obtain CeO 2 -GO hybrid material. The composite anti-corrosion coating has certain application potential in actual production work. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The cerium dioxide-graphene oxide (CeO 2 Schematic diagram of the preparation of hybrid materials of GO-GO;

[0026] Figure 2 f-GO and f-CeO are proposed in Example 1 of the present invention. 2 and CeO 2 -Infrared spectrum of GO;

[0027] Figure 3 Tafel polarization curves of different coating samples proposed in Example 1 of the present invention after being immersed in 3.5 wt % NaCl solution for 3 days. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with embodiments. The following embodiments are only used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0029] Example 1

[0030] (1) Preparation of graphene oxide dispersion: Graphene oxide was prepared according to the improved Hummer method. 2 g of flake graphite, 1 g of sodium nitrate and 60 ml of concentrated sulfuric acid were added to a three-necked beaker and stirred in an ice water bath at 0-5 °C for 2 h; then 6 g of potassium permanganate was added and the stirring reaction continued for 5 h; then the water bath temperature was raised to 45 °C and the stirring reaction continued for 30 min; 100 ml of deionized water was added and the water bath temperature was raised to 95 °C, and the magnetic stirring reaction continued for 30 min; 10 ml of hydrogen peroxide solution was added and the stirring continued until no obvious bubbles were generated. The mixture after the reaction was completed was centrifuged to obtain the lower layer of GO colloid; the lower layer of GO colloid was repeatedly washed with dilute hydrochloric acid solution and deionized water and centrifuged until the pH value of the upper clear liquid was neutral; the washed GO colloid was evenly dispersed in deionized water to obtain 500 ml of GO dispersion.

[0031] (2) Preparation of Cerium Oxide-Graphene Oxide Hybrid Materials:

[0032] 1. Take 2g of nano cerium dioxide (CeO 2 ), 1ml acetic acid, 90ml anhydrous ethanol and 10ml deionized water were added to a three-necked flask, and ultrasonic dispersion was performed for 30min to prepare liquid A; 2ml γ-glycidyloxypropyltrimethoxysilane (GPTS), 90ml anhydrous ethanol and 10ml were added to a beaker, and ultrasonic dispersion was performed for 30min to prepare liquid B; liquid B was slowly dripped into liquid A, and magnetic stirring was refluxed in an oil bath at 65°C for 6h to obtain a uniform turbid milky white liquid; it was filtered with a microporous filter membrane, and washed with ethanol and deionized water for multiple times to obtain functionalized nano-cerium dioxide (f-CeO 2 ), and dried in a vacuum dryer at 60°C for 12 h.

[0033] 2. Take 100 ml of graphene oxide (GO) dispersion and add it to a three-necked flask for later use; take 100 ml of anhydrous ethanol and 2 ml of γ-aminopropyltriethoxysilane (APTS) and add them to the three-necked flask, and ultrasonically disperse for 10 minutes to prepare liquid C; slowly drip liquid C into the GO dispersion, and reflux with magnetic stirring in a 65°C oil bath for 4 hours, and then cool to room temperature to obtain a mixture liquid with a precipitate; filter with a microporous filter membrane, and wash with ethanol and deionized water several times to obtain functionalized graphene oxide (f-GO), and place it in a vacuum dryer and dry it at 60°C for 12 hours.

[0034] 3. Take 2g f-CeO 2 , 1 g f-GO and 200 ml N,N-dimethylformamide (DMF) were added into a three-necked flask, ultrasonically dispersed for 1 h to make them uniformly mixed, and magnetically stirred and refluxed for 12 h in an oil bath at 110 °C to obtain a uniform turbid mixture liquid; filtered with a microporous filter membrane, and washed with ethanol and deionized water for several times to obtain cerium dioxide-graphene oxide (CeO 2 -GO) hybrid material was placed in a vacuum dryer at 60 °C for 12 h.

[0035] (3) Preparation of cerium dioxide-graphene oxide hybrid material / epoxy resin composite coating: A 40 mm × 20 mm × 1 mm Q235 steel plate was selected as the substrate of the epoxy resin composite coating. First, the surface of the Q235 steel plate was polished with 500 mesh and 1000 mesh sandpaper, and the excess grease on the surface of the steel plate was removed with acetone and anhydrous ethanol. 50 mg GO-CeO 2 (0.50wt%) was ultrasonically dispersed in 15ml of anhydrous ethanol, and then epoxy resin was added. After magnetic stirring for 30min, curing agent was added and stirred for 15min. The epoxy resin mixture after stirring was removed by rotary evaporation and then evenly sprayed on a Q235 steel plate. It was cured at room temperature for 24h and then cured at 60℃ for 12h to obtain a uniform 0.50wt% GO-CeO 2 / EP composite coating. In order to explore the GO-CeO 2 The effect of the amount of hybrid materials in epoxy resin coating on its anti-corrosion performance was studied. 1.00wt%, 1.50wt% and 2.00wt% GO-CeO 2 For comparison, 0.50wt% f-GO / EP composite coating and pure EP coating were prepared according to the same preparation process.

[0036] Example 2

[0037] (1) Preparation of graphene oxide dispersion: Graphene oxide was prepared according to the improved Hummer method. 2 g of flake graphite, 1 g of sodium nitrate and 60 ml of concentrated sulfuric acid were added to a three-necked beaker and stirred in an ice water bath at 0-5 °C for 2 h; then 6 g of potassium permanganate was added and the stirring reaction continued for 5 h; then the water bath temperature was raised to 45 °C and the stirring reaction continued for 30 min; 100 ml of deionized water was added and the water bath temperature was raised to 95 °C, and the magnetic stirring reaction continued for 30 min; 10 ml of hydrogen peroxide solution was added and the stirring continued until no obvious bubbles were generated. The mixture after the reaction was completed was centrifuged to obtain the lower layer of GO colloid; the lower layer of GO colloid was repeatedly washed with dilute hydrochloric acid solution and deionized water and centrifuged until the pH value of the upper clear liquid was neutral; the washed GO colloid was evenly dispersed in deionized water to obtain 500 ml of GO dispersion.

[0038] (2) Preparation of Cerium Oxide-Graphene Oxide Hybrid Materials:

[0039] 1. Take 2g of nano cerium dioxide (CeO 2 ), 1ml acetic acid, 90ml anhydrous ethanol and 10ml deionized water were added to a three-necked flask, and ultrasonic dispersion was performed for 30min to prepare liquid A; 2ml γ-glycidyloxypropyltrimethoxysilane (GPTS), 90ml anhydrous ethanol and 10ml were added to a beaker, and ultrasonic dispersion was performed for 30min to prepare liquid B; liquid B was slowly dripped into liquid A, and magnetic stirring was refluxed in an oil bath at 65°C for 6h to obtain a uniform turbid milky white liquid; it was filtered with a microporous filter membrane, and washed with ethanol and deionized water for multiple times to obtain functionalized nano-cerium dioxide (f-CeO 2 ), and dried in a vacuum dryer at 60°C for 12 h.

[0040] 2. Take 100 ml of graphene oxide (GO) dispersion and add it to a three-necked flask for later use; take 100 ml of anhydrous ethanol and 2 ml of γ-aminopropyltriethoxysilane (APTS) and add them to the three-necked flask, and ultrasonically disperse for 10 minutes to prepare liquid C; slowly drip liquid C into the GO dispersion, and reflux with magnetic stirring in a 65°C oil bath for 4 hours, and then cool to room temperature to obtain a mixture liquid with a precipitate; filter with a microporous filter membrane, and wash with ethanol and deionized water several times to obtain functionalized graphene oxide (f-GO), and place it in a vacuum dryer and dry it at 60°C for 12 hours.

[0041] 3. Take 2g f-CeO 2, 1 g f-GO and 200 ml N,N-dimethylformamide (DMF) were added into a three-necked flask, ultrasonically dispersed for 1 h to make them uniformly mixed, and magnetically stirred and refluxed for 12 h in an oil bath at 110 °C to obtain a uniform turbid mixture liquid; filtered with a microporous filter membrane, and washed with ethanol and deionized water for several times to obtain cerium dioxide-graphene oxide (CeO 2 -GO) hybrid material was placed in a vacuum dryer at 60 °C for 12 h. Figure 2 f-GO, f-CeO 2 and CeO 2 -GO infrared spectrum. It can be seen from the figure that at 3440cm -1 A strong and broad absorption peak appeared near the -OH stretching vibration, and its absorption peak intensity is closely related to the physically adsorbed water, the residual hydroxyl groups of the silane coupling agent after hydrolysis and condensation, and the hydroxyl groups on the carbon skeleton of graphene oxide. The infrared absorption curve of f-GO is at 3327cm -1 The absorption peak at 1136 cm is caused by the stretching vibration of NH. -1 The Si-O stretching vibration absorption peak appeared at 1136 cm -1 The Si-O stretching vibration absorption peak also appeared at 1040 cm -1 and 682cm -1 The characteristic absorption peaks of COC and Ce-O appeared at 2 Successfully synthesized. 2 -GO infrared absorption curve 1650cm -1 The absorption peaks near 3327 cm are caused by C=C / CC on the GO carbon skeleton and CC on the carbon chain of the original silane coupling agent. -1 、1136cm -1 and 682cm -1 The characteristic absorption peaks of NH, Si-O and Ce-O appeared at the 2 -GO hybrid materials.

[0042] (3) Preparation of cerium dioxide-graphene oxide hybrid material / epoxy resin composite coating: A 40 mm × 20 mm × 1 mm Q235 steel plate was selected as the substrate of the epoxy resin composite coating. First, the surface of the Q235 steel plate was polished with 500 mesh and 1000 mesh sandpaper, and the excess grease on the surface of the steel plate was removed with acetone and anhydrous ethanol. 50 mg GO-CeO 2(0.50wt%) was ultrasonically dispersed in 15ml of anhydrous ethanol, and then epoxy resin was added. After magnetic stirring for 30min, curing agent was added and stirred for 15min. The epoxy resin mixture after stirring was removed by rotary evaporation and then evenly sprayed on a Q235 steel plate. It was cured at room temperature for 24h and then cured at 60℃ for 12h to obtain a uniform 0.50wt% GO-CeO 2 / EP composite coating. In order to explore the GO-CeO 2 The effect of the amount of hybrid materials in epoxy resin coating on its anti-corrosion performance was studied. 1.00wt%, 1.50wt% and 2.00wt% GO-CeO 2 For comparison, 0.50wt% f-GO / EP composite coating and pure EP coating were prepared according to the same preparation process.

[0043] Depend on Figure 3 It can be concluded that among all samples, Q235 bare steel sample has the lowest E corr value (-710mV) and the maximum i corr Value (7.83×10 -4 A.cm -2 ), indicating that the bare Q235 steel sample is quite sensitive to corrosion. When the bare Q235 steel is covered with pure EP coating, its E corr The value moves positively, and the corresponding i corr The value was significantly reduced by 7 orders of magnitude, indicating that the epoxy resin coating has a certain barrier effect on external corrosive substances and improves its corrosion resistance to a certain extent. 2 -GO hybrid materials, the anti-corrosion performance of the prepared composite coating is even better; compared with the anti-corrosion performance of epoxy resin, a series of CeO 2 -GO / EP coated E corr The values ​​are all moving in the positive direction, and the corresponding i corr The value is reduced by 1 to 2 orders of magnitude. 2 -GO / EP has the lowest i corr Value (8.42×10 -13 A.cm -2 ) and higher E corr value (-65mV), indicating that its anti-corrosion performance is the best among all coating samples.

[0044] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a CeO2-GO hybrid material / epoxy resin composite anti-corrosion coating, characterized in that: The following steps are involved: S1. Preparation of graphene oxide dispersion: Graphene oxide is prepared according to the improved Hummer method, which specifically includes the following contents: S1.

1. Add flake graphite, sodium nitrate and concentrated sulfuric acid into a three-necked beaker and stir in an ice-water bath to react; S1.2, add potassium permanganate and continue stirring the reaction; S1.3, increase the water bath temperature and continue stirring the reaction; S1.

4. Add deionized water, continue to increase the water bath temperature, and continue the magnetic stirring reaction; S1.

5. Add hydrogen peroxide solution and continue stirring until no obvious bubbles are generated; S1.6, centrifuging the mixture after the reaction to obtain a lower layer of graphene oxide colloid; S1.7, repeatedly washing the lower layer of graphene oxide colloid with dilute hydrochloric acid solution and deionized water and centrifuging until the pH value of the upper clear liquid is neutral; S1.8, uniformly dispersing the washed graphene oxide colloid in deionized water to obtain a graphene oxide dispersion; S2. Preparation of Ceria-Graphene Oxide Hybrid Material: S2.

1. Add nano-cerium dioxide, acetic acid, anhydrous ethanol and deionized water into a three-necked flask, and ultrasonically disperse to obtain liquid A; add γ-glycidyloxypropyltrimethoxysilane, anhydrous ethanol and deionized water into a beaker, and ultrasonically disperse to obtain liquid B; slowly drip liquid B into liquid A, and reflux under magnetic stirring in an oil bath to obtain a uniform turbid milky white liquid; filter with a microporous filter membrane, and wash with ethanol and deionized water several times to obtain functionalized nano-cerium dioxide, and dry in a vacuum environment; S2.2, add the graphene oxide dispersion into a three-necked flask for later use; add anhydrous ethanol and γ-aminopropyltriethoxysilane into a three-necked flask, and ultrasonically disperse to prepare liquid C; slowly drip liquid C into the graphene oxide dispersion, and reflux under magnetic stirring in an oil bath for reaction, and cool to room temperature to obtain a mixture liquid with precipitate generated; filter with a microporous filter membrane, and wash with ethanol and deionized water for multiple times to obtain functionalized graphene oxide, and place in a vacuum environment for further processing; S2.3, add functionalized nano-cerium dioxide, functionalized graphene oxide and N,N-dimethylformamide into a three-necked flask, disperse by ultrasonication to mix them evenly, stir them under magnetic reflux reaction in an oil bath to obtain a uniform turbid mixture liquid; filter with a microporous filter membrane, wash with ethanol and deionized water several times to obtain a cerium dioxide-graphene oxide hybrid material, and dry it in a vacuum environment; S3. Preparation of Cerium Dioxide-Graphene Oxide Hybrid Material / Epoxy Resin Composite Coating: S3.

1. Select Q235 steel plate as the substrate of epoxy resin composite coating, polish the surface of Q235 steel plate with sandpaper, and remove excess grease on the surface of steel plate with acetone and anhydrous ethanol; S3.

2. Take 0.50wt% cerium dioxide-graphene oxide hybrid material and ultrasonically disperse it in anhydrous ethanol, then add epoxy resin, and after magnetic stirring, add curing agent and continue stirring. After the stirring, remove the anhydrous ethanol from the epoxy resin mixture by rotary evaporation and evenly spray it on a Q235 steel plate. Curing it at room temperature for a certain time, and then continue curing at a specific temperature to obtain a uniform 0.50wt% cerium dioxide-graphene oxide hybrid material / epoxy resin composite coating.

2. The method for preparing a CeO2-GO hybrid material / epoxy resin composite anti-corrosion coating according to claim 1, characterized in that: The mass ratio of flake graphite and sodium nitrate in S1.1 is flake graphite: sodium nitrate = 2-4: 1-2, and the concentrated sulfuric acid needs to be excessive; the temperature of the ice water bath is 0-5°C, and the stirring reaction time is 2h; The mass of potassium permanganate added in S1.2 is 6-9 g, and the stirring reaction time is 5 h; The water bath temperature in S1.3 is 45°C, and the stirring reaction time is 30 min; The volume of deionized water in S1.4 is 100 ml, the water bath temperature is 95°C, and the magnetic stirring reaction time is 30 min; The volume of the hydrogen peroxide solution described in S1.5 is 10 ml.

3. The method for preparing a CeO2-GO hybrid material / epoxy resin composite anti-corrosion coating according to claim 1, characterized in that: The molar ratio of nano-cerium dioxide and γ-glycidyloxypropyltrimethoxysilane in S2.1 is nano-cerium dioxide:γ-glycidyloxypropyltrimethoxysilane=1:1-2; wherein, acetic acid in liquid A and anhydrous ethanol and deionized water in liquids A and B are in excess, and the ultrasonic dispersion time is 30 minutes; In S2.1, the oil bath temperature is 65°C, and the magnetic stirring reflux reaction time is 6h; The temperature of the drying operation in S2.1 is 80°C and the drying time is 12h.

4. The method for preparing a CeO2-GO hybrid material / epoxy resin composite anti-corrosion coating according to claim 3, characterized in that: The molar ratio of the graphene oxide dispersion to γ-aminopropyltriethoxysilane in S2.2 is graphene oxide dispersion: γ-aminopropyltriethoxysilane = 1: 6-8, anhydrous ethanol is in excess, and the ultrasonic dispersion time is 10 min; In S2.2, the oil bath temperature is 65°C, and the magnetic stirring reflux reaction time is 4 h; The temperature of the drying operation in S2.2 is 60°C and the drying time is 12h.

5. The method for preparing a CeO2-GO hybrid material / epoxy resin composite anti-corrosion coating according to claim 4, characterized in that: The molar ratio of functionalized nano-cerium dioxide to functionalized graphene oxide in S2.3 is functionalized nano-cerium dioxide: functionalized graphene oxide = 1:1-2, N,N-dimethylformamide is excessive, and the ultrasonic dispersion time is 1h; In S2.3, the oil bath temperature is 110°C, and the magnetic stirring reflux reaction time is 12 h; The temperature of the drying operation in S2.3 is 60°C and the drying time is 12h.

6. The method for preparing a CeO2-GO hybrid material / epoxy resin composite anti-corrosion coating according to claim 1, characterized in that: The size of the Q235 steel plate in S3.1 is 40 mm × 20 mm × 1 mm, and the grinding of the Q235 steel plate is completed using 500-mesh and 1000-mesh sandpaper respectively; The mass of the 0.50wt% cerium dioxide-graphene oxide hybrid material described in S3.2 is 45-55mg, and anhydrous ethanol is in excess; the magnetic stirring time is 30min; after adding the curing agent, the stirring time is continued for 15min; the room temperature curing time is 24h, and then cured at a specific temperature of 60°C for 12h.

7. A CeO2-GO hybrid material / epoxy resin composite anti-corrosion coating prepared according to any one of claims 1-6.

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