Preparation and application of graphene oxide-polyaspartic acid nanomaterial corrosion inhibitor

Abstract

The application belongs to the field of metal corrosion protection, and discloses a preparation method of graphene oxide-polyaspartic acid nanomaterial, which comprises the following steps: dispersing nano graphene oxide in a solvent to obtain a nano graphene oxide dispersion; dissolving polyaspartic acid, 4-dimethylaminopyridine and N,N-dicyclohexyl carbodiimide in an organic solvent to obtain a polyaspartic acid mixture; uniformly mixing the nano graphene oxide dispersion and the polyaspartic acid mixture according to a mass ratio of 1:1-1.5 of the nano graphene oxide and the polyaspartic acid, and performing a reaction under the protection of a certain temperature and an inert atmosphere; and after the reaction is completed, performing solid-liquid separation and collecting a solid product, namely, graphene oxide-polyaspartic acid nanomaterial. The corrosion inhibitor of the application can achieve efficient corrosion inhibition effect by adding a small amount of the corrosion inhibitor into water, and the operation is simple and the cost is low.

Description

Technical Field

[0001] This invention belongs to the field of metal corrosion protection, and specifically relates to the preparation and application of a graphene oxide-polyaspartic acid nanomaterial corrosion inhibitor. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Metallic materials, with their excellent mechanical properties and low cost, are widely used in industries such as petroleum, chemical, and metallurgy. However, metallic materials are often damaged during application due to the effects of the surrounding environment, a phenomenon known as metal corrosion. Metal corrosion leads to the waste of resources and energy, delays production development, causes significant economic losses to countries and individuals, and can even cause safety accidents. Therefore, it is necessary to explore corresponding anti-corrosion measures based on the mechanisms of metal corrosion. Metal corrosion prevention can be mainly divided into physical shielding, electrochemical protection, and corrosion inhibitors. Among these, corrosion inhibitors are widely used in various industries due to their relatively simple and convenient operation and low cost. Currently, phosphorus-based corrosion inhibitors are the most commonly used, but they have drawbacks such as excessive phosphorus content in discharged wastewater, leading to water pollution and eutrophication. Therefore, green water treatment agents that meet the requirements of green chemistry have attracted attention.

[0004] Polyaspartic acid (PASP) is a polymeric amino acid with carboxylic acid side chains. Its main characteristics are non-toxicity, biodegradability, and no secondary pollution, making it an internationally recognized green water treatment agent. The carboxyl anions of PASP can combine with iron or copper ions to form a protective film on the metal surface, effectively preventing corrosion. However, the corrosion inhibition effect of PASP is greatly affected by water quality conditions, and its effectiveness is poor when used alone. To improve the corrosion inhibition effect of PASP, it is usually compounded with other corrosion inhibitors or modified.

[0005] Graphene oxide (GO) is a novel carbonaceous nanomaterial with a unique molecular structure and size effect. Due to its excellent properties such as biocompatibility, chemical stability, high dispersibility, large specific surface area, and abundant oxygen-containing functional groups, GO is a hot research topic in the field of nanomaterials. As a two-dimensional material, GO can act as a filler to compensate for the micropore defects that occur during the curing process of water-based coatings, and has received widespread attention and application in the field of anti-corrosion coatings. However, anti-corrosion coatings suffer from high costs and complex operations during application. Therefore, it is necessary to explore the application of GO in the field of corrosion inhibitors, which are simpler to operate and less costly. A search revealed no reports on using GO to improve the corrosion inhibition performance of PASP (paraffinic acid). Summary of the Invention

[0006] This invention addresses the problem that polyaspartic acid (PAA) requires high water quality and is ineffective when used alone during corrosion inhibition. It provides a nanomaterial corrosion inhibitor and opens up new application directions for graphene oxide. The main principle of this invention is to use graphene oxide as a carrier to combine PAA, forming ester bonds between the carboxyl groups of PAA and the hydroxyl groups of graphene oxide, thus forming a multilayer three-dimensional structure. Figure 2 and Figure 3 This allows corrosion ions to penetrate into the structure, resulting in a better corrosion inhibition effect compared to polyaspartic acid.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a method for preparing graphene oxide-polyaspartic acid nanomaterials, comprising:

[0009] Nano-graphene oxide is dispersed in a solvent to obtain a nano-graphene oxide dispersion.

[0010] Polyaspartic acid, 4-dimethylaminopyridine and N,N-dicyclohexylcarbodiimide were dissolved in an organic solvent to obtain a polyaspartic acid mixture.

[0011] The nano-graphene oxide dispersion and the polyaspartic acid mixture were mixed evenly at a mass ratio of 1:1-1.5. The mixture was then reacted under a certain temperature and an inert atmosphere. After the reaction was completed, the solid and liquid were separated, and the solid product was collected, namely: graphene oxide-polyaspartic acid nanomaterial.

[0012] In some embodiments, the mass concentration of the nano-graphene oxide dispersion is:

[0013] 0.01~0.015g / mL.

[0014] In some embodiments, the method for preparing the nano-graphene oxide includes:

[0015] Graphite powder is added to concentrated sulfuric acid to obtain a graphite solution;

[0016] Add KNO3 to the graphite solution and mix well; then add KMnO4 and mix well, then stir at 35℃-40℃ for 30min-40min; then add water, heat to 98℃-99℃, and stir for 30min-40min to obtain a mixed solution.

[0017] Water at 60℃-65℃ was added to the mixed solution to cool it down, and then H2O2 was added. The reaction was carried out under sealed conditions. After the reaction was completed, the solid and liquid were separated, the solid product was collected, washed, freeze-dried, and ground to obtain nanoparticles.

[0018] In some embodiments, the preparation method of the nano-graphene oxide dispersion is as follows: mix nano-graphene oxide with dimethyl sulfoxide and sonicate for 30 min-40 min to obtain the dispersion.

[0019] In some embodiments, the mass ratio of the polyaspartic acid to 4-dimethylaminopyridine is 0.1:0.006-0.008.

[0020] In some embodiments, the mass ratio of the polyaspartic acid to N,N-dicyclohexylcarbodiimide is 0.1:0.05-0.08.

[0021] In some embodiments, the mass concentration of polyaspartic acid in the polyaspartic acid mixture is 0.006–0.01 g / mL.

[0022] In some embodiments, the reaction is carried out at 65°C-70°C under nitrogen atmosphere with stirring for 24-32 hours.

[0023] In a second aspect, the present invention provides a graphene oxide-polyaspartic acid nanomaterial corrosion inhibitor prepared by the above method.

[0024] A third aspect of the present invention provides the application of the above-mentioned graphene oxide-polyaspartic acid nanomaterial corrosion inhibitor in mitigating metal corrosion, wherein the metal includes, but is not limited to, Q235 carbon steel.

[0025] The corrosion inhibitor described in this invention requires only a small amount to be added to water to achieve a highly efficient corrosion inhibition effect, making the operation simpler and the cost lower. The key feature of this invention lies in utilizing the advantages of graphene oxide and polyaspartic acid, as well as the three-dimensional structure of the new nanomaterial formed by their polymerization. This allows it to both form a protective film on the metal surface and enhance the removal of corrosion ions.

[0026] Beneficial effects of the present invention

[0027] (1) Good corrosion inhibition effect. The corrosion inhibitor provided by the present invention can form a protective film on the metal surface. The multi-layer three-dimensional structure formed allows corrosion ions to enter the structure, thereby combining more corrosion ions and achieving a highly efficient corrosion inhibition effect.

[0028] (2) Environmentally friendly. The corrosion inhibitor used in this invention meets the requirements of green chemistry and will not cause secondary pollution when released into the environment.

[0029] (3) High operability. The corrosion inhibitor provided in this invention only needs to be added to the water body, which is simpler to operate than other corrosion inhibition methods.

[0030] (4) Low cost. The materials used in this invention are relatively inexpensive and the reaction conditions are relatively mild, resulting in relatively low cost for practical applications.

[0031] (5) The preparation method of the present invention is simple, practical and easy to promote. Attached Figure Description

[0032] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. Exemplary embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0033] Figure 1 The synthesis route of the corrosion inhibitor graphene oxide-polyaspartic acid nanomaterial described in this invention;

[0034] Figure 2 The three-dimensional structure of the corrosion inhibitor graphene oxide-polyaspartic acid nanomaterial described in this invention;

[0035] Figure 3 SEM comparison image of the corrosion inhibitor graphene oxide-polyaspartic acid nanomaterial and graphene oxide described in this invention;

[0036] Figure 4 Fourier transform infrared spectrum comparison of the corrosion inhibitor graphene oxide-polyaspartic acid nanomaterial, graphene oxide nanomaterial and polyaspartic acid described in this invention.

[0037] Figure 5 Raman comparison diagram of the corrosion inhibitor graphene oxide-polyaspartic acid nanomaterial and graphene oxide nanomaterial described in this invention;

[0038] Figure 6 Comparison of the proton nuclear magnetic resonance spectra of the corrosion inhibitor graphene oxide-polyaspartic acid nanomaterial, graphene oxide nanomaterial, and polyaspartic acid described in this invention.

[0039] Figure 7The corrosion inhibitor graph described in this invention compares the corrosion inhibition effects of graphene oxide-polyaspartic acid nanomaterials and graphene oxide nanomaterials and polyaspartic acid under different concentration conditions. Detailed Implementation

[0040] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0041] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention and not limitations thereof.

[0042] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0043] Example 1: Preparation and characterization of a corrosion inhibitor graphene oxide-polyaspartic acid nanomaterial, the specific steps of which are as follows:

[0044] (1) 1g of graphite powder is slowly added to concentrated sulfuric acid (in an ice-water bath with constant stirring), and cooled for 5 minutes after the addition is complete; then 0.5g of KNO3 is added to the solution over 30 minutes, and stirred for 2 hours in an ice-water bath; then 4.5g of KMnO4 is added to the solution at a rate of 0.25g every 10 minutes over 3 hours, and stirred for 2 hours after the addition is complete; then stirred for 30 minutes at a constant temperature of 35℃; then 63mL of deionized water is slowly added along the wall of the beaker, and the speed should not be too fast, and stirred for 5 minutes after the addition is complete; then the temperature is raised to 98℃ and stirred for 30 minutes; then 73mL of deionized water at 60℃ is slowly added, and the temperature is continuously lowered by stirring during the water addition process; finally, 1.4mL of 30% H2O2 is added, a thin film is placed over the mouth of the beaker, and the mixture is stirred and left to stand overnight.

[0045] (2) After standing, discard the supernatant, add deionized water and mix well. Dispense into centrifuge tubes and centrifuge at 8000 rpm for 10 min. Discard the supernatant, add more deionized water to half the volume, mix well, and repeat centrifugation until the pH of the supernatant is between 6 and 7, at which point washing can be stopped. After the precipitate is dried, sheet-like graphene oxide is obtained. The sheet-like graphene oxide is ground in a grinder at 500 rpm for 6 h at a material ratio of 30:1 to obtain graphene oxide nanoparticles, which are stored for later use.

[0046] (3) Take 0.1g of nano-graphene oxide and mix it with 10mL of dimethyl sulfoxide (DMSO) and sonicate for 30min; separately take 0.1g of PASP, 0.006g of 4-dimethylaminopyridine (DMAP) and 0.05g of N,N-dicyclohexylcarbodiimide (DCC) and dissolve them in 15mL of DMSO; mix the two solutions and stir at 65℃ under nitrogen atmosphere for 24h, then centrifuge the mixture at 8000rpm for 30min, discard the supernatant, wash the precipitate with deionized water 3 times and vacuum dry to obtain sheet-like graphene oxide-polyaspartic acid material, and then grind it in a grinder at 500rpm for 6h to obtain graphene oxide-polyaspartic acid nanomaterial;

[0047] (4) The prepared graphene oxide and graphene oxide-polyaspartic acid nanomaterials were scanned by scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and nuclear magnetic resonance hydrogen spectroscopy to compare the similarities and differences between the two.

[0048] The above results indicate that, through scanning electron microscopy (SEM) images ( Figure 3 It can be seen that the corrosion inhibitor graphene oxide-polyaspartic acid has a multilayer sheet structure and is smaller in size than graphene oxide; Fourier transform infrared spectroscopy (FTIR) shows that... Figure 4 The comparison shows that graphene oxide-polyaspartic acid exhibits no hydroxyl stretching vibration at 3318 cm⁻¹. -1 The stretching vibration peak of NH appears at 1038 cm⁻¹. -1 A CN peak appears at this location; through Raman spectroscopy ( Figure 5 It can be seen that the intensity of the D / G peak decreases, the graphitized carbon content decreases, and the AD / AG and ID / IG values ​​increase, indicating an increase in hybrids in the material, proving the synthesis of graphene oxide-polyaspartic acid; the comparison of the 1H NMR spectra shows that δ = 4.7 ppm is the chemical shift of D2O, and δ = 4.408 ppm... Figure 6 A(a)) and δ = 2.690 ppm ( Figure 6 The signals at A(b)) correspond to -CH- and -CH2- groups, respectively. δ = 1.56 ppm represents the chemical shift of CDCl3, and a value of δ = 4.12 ppm appears. Figure 6 C(a)) and δ = 2.630 ppm ( Figure 6 C(b)). Therefore, it can be concluded that the synthesis of graphene oxide-polyaspartic acid was successful.

[0049] Example 2: Application of a corrosion inhibitor graphene oxide-polyaspartic acid nanomaterial, the specific steps are as follows:

[0050] (1) Select 1×1×0.2cm 3The Q235 carbon steel was cleaned of surface grease and sanded with 400, 600 and 800 grit sandpaper until there were no obvious pits or scratches on the surface. It was then dried in a drying oven for 4 hours and weighed.

[0051] (2) Prepare simulated circulating cooling water. Dissolve 5.55g of anhydrous calcium chloride, 4.93g of magnesium sulfate heptahydrate and 6.58g of sodium chloride in about 7L of water. Mix them thoroughly after they are completely dissolved. Weigh out 1.68g of sodium bicarbonate and dissolve it in about 1L of water. Mix them thoroughly after they are completely dissolved. Mix the two solutions and bring the volume up to 10L.

[0052] (3) Add polyaspartic acid, graphene oxide and graphene oxide-polyaspartic acid with a concentration of 10 mg / L to the simulated circulating cooling water, and then put the dried carbon steel in sequence and soak it at 25°C and 100 rpm for 7 days.

[0053] (4) After the immersion experiment, the steel sheet was taken out and the corrosion products on the surface were cleaned with deionized water. The steel sheet was then cleaned with pickling solution and anhydrous ethanol respectively. After drying in a drying oven for 4 hours, it was weighed. The corrosion inhibition rate was calculated by calculating the weight loss of the steel sheet before and after the experiment.

[0054] The above results show that the novel nanomaterial corrosion inhibitor, graphene oxide-polyaspartic acid, described in this invention has a significantly higher corrosion inhibition effect than polyaspartic acid. The corrosion inhibition rate of polyaspartic acid alone was 8.54±2.29%, the corrosion inhibition rate of graphene oxide alone was 21.37±0.70%, while the corrosion inhibition rate of graphene oxide-polyaspartic acid was 27.35±1.85%. Figure 7 As can be seen, when the concentration used is 10 mg / L, the corrosion inhibition effect of polyaspartic acid alone is very poor, but graphene oxide has a certain corrosion inhibition effect, which is slightly lower than that of graphene oxide-polyaspartic acid at 10 mg / L.

[0055] Example 3: Application of a corrosion inhibitor graphene oxide-polyaspartic acid nanomaterial, the specific steps are as follows:

[0056] (1) Select 1×1×0.2cm 3 The Q235 carbon steel was cleaned of surface grease and sanded with 400, 600 and 800 grit sandpaper until there were no obvious pits or scratches on the surface. It was then dried in a drying oven for 4 hours and weighed.

[0057] (2) Prepare simulated circulating cooling water. Dissolve 5.55g of anhydrous calcium chloride, 4.93g of magnesium sulfate heptahydrate and 6.58g of sodium chloride in about 7L of water. Mix them thoroughly after they are completely dissolved. Weigh out 1.68g of sodium bicarbonate and dissolve it in about 1L of water. Mix them thoroughly after they are completely dissolved. Mix the two solutions and bring the volume up to 10L.

[0058] (3) Add polyaspartic acid, graphene oxide and graphene oxide-polyaspartic acid with a concentration of 40 mg / L to the simulated circulating cooling water, and then put the dried carbon steel in sequence and soak it at 25°C and 100 rpm for 7 days.

[0059] (4) After the immersion experiment, the steel sheet was taken out and the corrosion products on the surface were cleaned with deionized water. The steel sheet was then cleaned with pickling solution and anhydrous ethanol respectively. After drying in a drying oven for 4 hours, it was weighed. The corrosion inhibition rate was calculated by calculating the weight loss of the steel sheet before and after the experiment.

[0060] The above results show that the novel nanomaterial corrosion inhibitor, graphene oxide-polyaspartic acid, described in this invention has a significantly higher corrosion inhibition effect than polyaspartic acid. The corrosion inhibition rate of polyaspartic acid alone was 19.23±7.35%, the corrosion inhibition rate of graphene oxide alone was 8.12±2.12%, while the corrosion inhibition rate of graphene oxide-polyaspartic acid was 34.19±1.84%. Figure 7 Increasing the concentration of the corrosion inhibitor used increased the corrosion inhibition rate of polyaspartic acid, but it remained at a low level. The effect of graphene oxide also decreased, but the corrosion inhibition rate of graphene oxide-polyaspartic acid increased.

[0061] Example 4: Application of a corrosion inhibitor graphene oxide-polyaspartic acid nanomaterial, the specific steps are as follows:

[0062] (1) Select 1×1×0.2cm 3 The Q235 carbon steel was cleaned of surface grease and sanded with 400, 600 and 800 grit sandpaper until there were no obvious pits or scratches on the surface. It was then dried in a drying oven for 4 hours and weighed.

[0063] (2) Prepare simulated circulating cooling water. Dissolve 5.55g of anhydrous calcium chloride, 4.93g of magnesium sulfate heptahydrate and 6.58g of sodium chloride in about 7L of water. Mix them thoroughly after they are completely dissolved. Weigh out 1.68g of sodium bicarbonate and dissolve it in about 1L of water. Mix them thoroughly after they are completely dissolved. Mix the two solutions and bring the volume up to 10L.

[0064] (3) Add polyaspartic acid, graphene oxide and graphene oxide-polyaspartic acid with a concentration of 100 mg / L to the simulated circulating cooling water, and then put the dried carbon steel in sequence and soak it at 25°C and 100 rpm for 7 days.

[0065] (4) After the immersion experiment, the steel sheet was taken out and the corrosion products on the surface were cleaned with deionized water. The steel sheet was then cleaned with pickling solution and anhydrous ethanol respectively. After drying in a drying oven for 4 hours, it was weighed. The corrosion inhibition rate was calculated by calculating the weight loss of the steel sheet before and after the experiment.

[0066] The above results indicate that the novel nanomaterial corrosion inhibitor, graphene oxide-polyaspartic acid, described in this invention exhibits significantly higher corrosion inhibition performance than polyaspartic acid. The corrosion inhibition rate of polyaspartic acid alone was 8.55±4.37%, that of graphene oxide alone was 17.09±5.48%, while the corrosion inhibition rate of graphene oxide-polyaspartic acid was 34.62±5.23%. Figure 7 As can be seen, when the concentration is 100 mg / L, the corrosion inhibition rate of polyaspartic acid decreases, possibly because polyaspartic acid itself corrodes the steel sheet; graphene oxide is insoluble in water, resulting in unstable corrosion inhibition effect, while the corrosion inhibition effect of graphene oxide-polyaspartic acid is better and more stable than that of polyaspartic acid and graphene oxide alone.

[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing graphene oxide-polyaspartic acid nanomaterials, characterized in that, The method comprises the following steps: dispersing nano-oxidized graphene in a solvent to obtain a nano-oxidized graphene dispersion liquid; the mass concentration of the nano-oxidized graphene dispersion liquid is 0.01-0.015 g / mL; polyaspartic acid, 4-dimethylaminopyridine and N,N-dicyclohexyl carbodiimide are dissolved in an organic solvent to obtain a polyaspartic acid mixture; the nano-oxidized graphene dispersion liquid and the polyaspartic acid mixture are mixed uniformly at a mass ratio of nano-oxidized graphene to polyaspartic acid of 1:1-1.5, and then, under the protection of an inert atmosphere, the mixture is reacted at 65-70 DEG C; after the reaction is completed, solid-liquid separation is performed, and the solid product, i.e., an oxidized graphene-polyaspartic acid nanomaterial, is collected; the mass ratio of the polyaspartic acid to 4-dimethylaminopyridine is 0.1:0.006-0.008; the mass ratio of the polyaspartic acid to N,N-dicyclohexyl carbodiimide is 0.1:0.05-0.08; in the polyaspartic acid mixture, the mass concentration of the polyaspartic acid is 0.006-0.01 g / mL.

2. The method of claim 1, wherein the graphene oxide-polyaspartic acid nanomaterial is prepared by the steps of: (a) mixing graphene oxide and polyaspartic acid in a solvent to form a mixture; (b) adding a reducing agent to the mixture; and (c) drying the mixture. The preparation method of the nano-oxidized graphene comprises the following steps: adding graphite powder into concentrated sulfuric acid to obtain a graphite solution; adding KNO3 into the graphite solution and mixing uniformly; then, KMnO4 is added, and after mixing uniformly, the mixture is stirred at 35-40 DEG C for 30-40 min; then, water is added, and the temperature is increased to 98-99 DEG C; the mixture is stirred for 30-40 min to obtain a mixed solution; adding water at 60-65 DEG C into the mixed solution to reduce the temperature; then, H2O2 is added, and the mixture is reacted under a sealed condition; after the reaction is completed, solid-liquid separation is performed; the solid product is washed, freeze-dried and ground to obtain nano-particles.

3. The method of claim 1, wherein the graphene oxide-polyaspartic acid nanomaterial is prepared by the steps of: (a) mixing graphene oxide and polyaspartic acid in a solvent to form a mixture; (b) adding a reducing agent to the mixture; and (c) drying the mixture. The preparation method of the nano-oxidized graphene dispersion liquid is that nano-oxidized graphene is mixed with dimethyl sulfoxide and ultrasonically treated for 30-40 min.

4. The method of claim 1, wherein the graphene oxide-polyaspartic acid nanomaterial is prepared by the steps of: (a) mixing graphene oxide and polyaspartic acid in a solvent to form a mixture; (b) adding a reducing agent to the mixture; and (c) drying the mixture. The reaction condition is that the mixture is stirred for 24-32 h at 65-70 DEG C under a nitrogen atmosphere.

5. The graphene oxide-polyaspartic acid nanomaterial corrosion inhibitor prepared by the method of any one of claims 1-4.

6. The use of the graphene oxide-polyaspartic acid nanomaterial corrosion inhibitor of claim 5 in mitigating metal corrosion, characterized in that, The metal includes but is not limited to Q235 carbon steel.

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