CN-122010096-A - Carbon dot corrosion inhibitor with excellent corrosion inhibition and tracing performance, preparation method and application

CN122010096ACN 122010096 ACN122010096 ACN 122010096ACN-122010096-A

Abstract

The invention discloses a carbon dot corrosion inhibitor with excellent corrosion inhibition and tracing performances, a preparation method and application thereof, and relates to the technical field of corrosion inhibition of metal materials. The method solves the technical problems that the carbon dot corrosion inhibitor in the prior art is easy to aggregate and unstably and single in application under a high-temperature strong acid environment. The method comprises the steps of firstly taking citric acid and propargyl-PEG 2-amine as raw materials, dissolving the raw materials in deionized water to obtain a mixed solution, placing the mixed solution in a high-pressure reaction kettle for hydrothermal reaction to prepare propargyl-PEG 2-amine modified citric acid carbon dots, and sequentially centrifuging, dialyzing and freeze-drying the propargyl-PEG 2-amine modified citric acid carbon dots to obtain the finished product. The carbon dot corrosion inhibitor prepared by the method can be used as a corrosion inhibition material in a high-temperature resistant strong acid environment, and can be used for in-situ monitoring of dichromate ions in industrial wastewater and in-situ monitoring of iron ions and ferrous ions in underground water, surface water and drinking water so as to judge whether the content of the carbon dot corrosion inhibitor exceeds the standard.

Inventors

WANG QI
LIU SIYU
WANG ZHIKUN
WANG JINGYUE
FU YU
WANG XIUMIN
HU SONGQING

Assignees

中国石油大学(华东)

Dates

Publication Date: 20260512
Application Date: 20260309

Claims (9)

1. The preparation method of the carbon dot corrosion inhibitor with excellent corrosion inhibition and tracing performance is characterized by sequentially comprising the following steps of: a. citric acid and propargyl-PEG 2-amine are taken as raw materials, and are placed in deionized water to be dissolved, so that a mixed solution is obtained, wherein the molar ratio of the citric acid to the propargyl-PEG 2-amine is 1:2; b. placing the mixed solution into a high-pressure reaction kettle for hydrothermal reaction, wherein the hydrothermal reaction temperature is 150 ℃, the reaction time is 7-9 hours, and in the hydrothermal reaction process, carboxyl on citric acid and amino in propargyl-PEG 2-amine are subjected to amidation reaction to prepare propargyl-PEG 2-amine modified citric acid carbon dots; c. And (3) sequentially centrifuging, dialyzing and freeze-drying the propargyl-PEG 2-amine modified citric acid carbon dots to obtain the product.
2. The method for preparing the carbon dot corrosion inhibitor with excellent corrosion inhibition and tracing performance according to claim 1, wherein in the step a, citric acid and propargyl-PEG 2-amine are dissolved in 15-25 mL of deionized water.
3. The method for preparing the carbon dot corrosion inhibitor with excellent corrosion inhibition and tracing performance according to claim 1, wherein in the step c, the centrifugation treatment step is to centrifugally treat the propargyl-PEG 2-amine modified citric acid carbon dot at the rotation speed of 10000 rpm, remove particles and collect a clarified solution.
4. The method for preparing the carbon dot corrosion inhibitor with excellent corrosion inhibition and tracing performance according to claim 3, wherein the dialysis step is characterized in that the collected clarified solution is placed in a dialysis bag with a molecular weight cut-off of 500 Da, dialysis is carried out in 500 mL deionized water, and dialysis water is replaced every 2-3 hours until the dialysis external liquid becomes transparent and colorless.
5. The method for preparing the carbon dot corrosion inhibitor with excellent corrosion inhibition and tracing performance according to claim 4, wherein the freeze drying treatment step is that the solution obtained by dialysis is freeze dried for 70-75 hours to obtain a brown solid product, namely the carbon dot corrosion inhibitor.
6. The carbon dot corrosion inhibitor with excellent corrosion inhibition and tracing performance is characterized in that the carbon dot corrosion inhibitor is prepared by the preparation method of any one of claims 1-5, the particle size of the carbon dot corrosion inhibitor is 1.881-2.595 nm, the carbon dot corrosion inhibitor comprises a carbon core and a surface layer, the carbon core is graphitized carbon core, and the surface layer is carbon dots modified by propargyl-PEG 2-amine through amidation reaction.
7. The method of claim 6, wherein the carbon dot corrosion inhibitor is used in corrosion environment of 1mol/L HCl at 30 deg.C or 90 deg.C, and as fluorescent probe for monitoring iron ions and ferrous ions in groundwater, surface water and drinking water and for monitoring dichromate ions in industrial wastewater.
8. The method for preparing the carbon dot corrosion inhibitor with excellent corrosion inhibition and tracing performance, as set forth in claim 7, wherein when the carbon dot corrosion inhibitor is applied to a 1mol/L HCl corrosion environment with a temperature of 30 ℃ or 90 ℃, nitrogen elements on the surface of the carbon dot corrosion inhibitor are protonated to form coordination action with iron ions, and are adsorbed on the surface of iron by virtue of electrostatic attraction action with Cl - adsorbed on the surface of the iron to form a protective layer, meanwhile, PEG2 chain segments form a hydrophilic hydration layer on the surface of the carbon dot, van der Waals attraction among particles is weakened through a steric hindrance effect, dispersion stability of the carbon dot corrosion inhibitor in the corrosion environment is enhanced, and a compact and uniform protective layer is formed to reduce corrosion of metals.
9. The application of the carbon dot corrosion inhibitor with excellent corrosion inhibition and tracing performance as claimed in claim 7, wherein the carbon dot corrosion inhibitor is used as a fluorescent probe, and when monitoring heavy chromate ions in industrial wastewater and monitoring iron ions and ferrous ions in surface water, underground water and drinking water, active groups of the carbon dot corrosion inhibitor coordinate with the iron ions and the ferrous ions, and oxidation reduction or electrostatic interaction with the heavy chromate ions causes photoelectric induction transfer or internal filtration effect, so that fluorescent quenching occurs to the carbon dot, and the monitoring of the iron ions, the ferrous ions and the heavy chromate ions is realized.

Description

Carbon dot corrosion inhibitor with excellent corrosion inhibition and tracing performance, preparation method and application Technical Field The invention relates to the technical field of corrosion inhibition of metal materials, in particular to a carbon dot corrosion inhibitor with excellent corrosion inhibition and tracing performances, a preparation method and application. Background N80 steel is widely applied to the fields of petroleum drilling and production, oil gas transportation and the like by virtue of excellent mechanical properties, weldability, toughness and impact resistance, but is extremely easy to corrode in the acidification treatment of an oil well and the industrial pickling process. In order to reduce the corrosion of metals in industrial processes, the addition of corrosion inhibitors to the corrosive medium is an economically effective means of protection. The traditional corrosion inhibitor contains nitrogen, sulfur, phosphorus and other electronegative heteroatoms or unsaturated bonds, can play a role in inhibiting corrosion by forming an adsorption layer on the surface of metal, but has the problems of high toxicity, great environmental hazard and the like, and is contrary to the green development concept. Therefore, development of green, low-cost, high-efficiency corrosion inhibitors and iron ion stabilizers is the current focus of research. The continuing development of industry and manufacturing has led to increasingly serious wastewater discharge problems with heavy metal ions (e.g., excess ferric ions) and highly oxidizing oxyacid radical ions (e.g., dichromate ions), which are diffused through the water environment and enter the food chain, posing a serious threat to human health. Among them, dichromate ions have strong carcinogenicity, while excessive ferric ions can induce organ function injury and cause damage to heart, lung, liver and kidney, etc. Therefore, the method for identifying the specific ions in the water body with high selectivity and high sensitivity is developed, which not only has important significance for environmental pollution prevention and control, but also provides reference for early corrosion visual monitoring. Carbon dots have received great attention in various fields such as corrosion protection, biological imaging, energy storage, photocatalysis, biochemical sensing and the like due to their excellent water solubility, good biocompatibility, low toxicity and unique fluorescence characteristics. In the field of corrosion protection, CDs-based materials have demonstrated excellent corrosion inhibition performance as novel green corrosion inhibitors. The remarkable quantum confinement effect and edge effect enable the electron-rich heteroatom doped carbon dots to change the electron properties remarkably. By introducing various functional groups (such as-NH 2, -COOH, -SH, -OH), doping provides rich active sites, and pi electron interaction, metal-ligand coordination and synergistic effect are remarkably enhanced, so that firm adsorption of carbon points on the metal surface is promoted, and uniform protective films are formed. Carbon dots have therefore found widespread use in the area of corrosion protection. Meanwhile, CDs are also widely used as fluorescence sensors for various analytes, such as detection of iron ions, dichromate ions, chromium ions, copper ions, etc., by virtue of tunable optical properties and high quantum yields. The surface functional group of the fluorescent dye forms a complex with target ions to cause fluorescence quenching effect, so that the selective identification of the object to be detected is realized. The preparation method of the CDs-based material in the prior art mainly comprises a hydrothermal/solvent method, a microwave-assisted method, a pyrolysis method and an electrochemical synthesis method, wherein in the hydrothermal/solvent method, a carbon source such as citric acid, biomass and a doping agent such as urea and thiourea are dissolved in a water/organic solvent, then the water/organic solvent is placed in a high-pressure reaction kettle to react for 4-12 hours at 160-220 ℃, and pure carbon points are obtained after cooling, centrifugation, dialysis and drying. However, the method has the technical problems that the first reaction is carried out in a closed high-pressure heterogeneous system, carbonization, nucleation and growth rate of a carbon source are not synchronous in the reaction process, agglomerates or amorphous carbon black impurities are easy to appear and directly influence water solubility, and the carbon dots prepared by the second prior art cannot be used as carbon dot corrosion inhibitors in a high-temperature strong acid environment because of the defect that the traditional corrosion inhibitors are easy to aggregate and unstably in the environment. Under the high-temperature environment, the surface functional groups (such as carboxyl and hydroxyl) of the citric acid carbon point c