A method for preparing zinc molybdate and its application in preventing metal corrosion.

Abstract

This invention provides a method for preparing zinc molybdate and its application in preventing metal corrosion, relating to the field of chemical technology. For the first time, this invention utilizes sodium dodecylbenzenesulfonate (SDBS), polyoxyethylene-polyoxypropylene block copolymer (F-68), and polyacrylamide (PAM) to prepare novel zinc molybdates with different morphologies via a hydrothermal method. In this invention, the aforementioned novel zinc molybdate is introduced as a functional filler into epoxy resin to prepare a composite anti-corrosion coating. It was found that the prepared anti-corrosion coating exhibits superior long-term anti-corrosion performance, providing a theoretical basis and experimental foundation for developing efficient and controllable zinc molybdate-based anti-corrosion fillers.

Description

Technical Field

[0001] This application relates to the field of chemical technology, and in particular to a method for preparing zinc molybdate and its application in preventing metal corrosion. Background Technology

[0002] Metal corrosion causes enormous losses to the national economy and industrial production every year, making the development of efficient and environmentally friendly anti-corrosion coatings a research hotspot in materials science and surface engineering. Epoxy resin (EP) is widely used as a substrate for metal anti-corrosion coatings due to its excellent adhesion, chemical resistance, and mechanical properties. However, pure epoxy coatings are prone to defects such as curing shrinkage and internal microcracks, leading to the absorption of corrosive media (Cl). - Oxygen ions (such as oxygen, oxygen, and hydrogen) gradually penetrate into the metal substrate, causing localized corrosion and even coating peeling. Therefore, introducing functional fillers into epoxy resin and utilizing the physical barrier effect and electrochemical passivation effect of the fillers to improve the anti-corrosion performance of the coating is the simplest, most convenient, and effective strategy.

[0003] Zinc molybdate (ZnMoO4), as an environmentally friendly inorganic corrosion inhibitor, has attracted widespread attention due to its unique layered or chain-like crystal structure and excellent ion exchange capacity. Studies have shown that when corrosive media penetrate the coating and reach the metal interface, the MoO4 in ZnMoO4... 2- Able to interact with Cl - Exchange or being replaced by OH - Released through displacement, and subsequently reacting with Fe produced by corrosion of the metal substrate. 2+ / Fe 3+ The reaction forms a dense, insoluble ferric molybdate (Fe2(MoO4)3) or Fe-Mo-O composite passivation film on the metal surface, effectively inhibiting the anodic dissolution process. This "ion trapping-passivation film formation" mechanism endows zinc molybdate with unique active protective functions, distinguishing it from traditional inert sheet-like fillers (such as mica, glass flakes, etc.). The anti-corrosion efficacy of zinc molybdate depends not only on its chemical composition but also on its microstructure, particle size distribution, and dispersion state in the coating. In recent years, researchers have attempted to synthesize ZnMoO4 with different morphologies, such as nanorods, nanosheets, microspheres, and hierarchical structures, through hydrothermal / solvothermal methods, precipitation methods, and template methods. Among these, the surfactant-assisted hydrothermal method is favored due to its simple operation, mild conditions, and ability to effectively control the anisotropic growth of crystals. Surfactants can selectively adsorb onto specific crystal faces, changing the surface energy and growth rate of the crystal faces, thereby guiding diverse microstructures such as nanosheets, nanoflowers, and spherical aggregates. However, the regulatory mechanisms of different surfactants on the morphology evolution of ZnMoO4 are still unclear, especially the structure-property relationship between morphology and coating corrosion resistance lacks systematic research. Summary of the Invention

[0004] Based on the above problems, this application uses zinc nitrate hexahydrate and sodium molybdate as raw materials to controllably prepare ZnMoO4 materials with different morphologies through a surfactant-assisted hydrothermal method. These materials are then introduced into epoxy resin as functional fillers to prepare composite anti-corrosion coatings, providing a theoretical basis and experimental foundation for the development of efficient and controllable zinc molybdate-based anti-corrosion fillers.

[0005] On one hand, this application provides a method for preparing zinc molybdate, the method comprising: mixing zinc nitrate, sodium molybdate, and a surfactant, and preparing zinc molybdate by hydrothermal method; wherein the surfactant is selected from one or more of sodium dodecylbenzenesulfonate (SDBS), polyoxyethylene polyoxypropylene block copolymer (F-68), and polyacrylamide (PAM).

[0006] Further, the concentration of the surfactant is 5-15 g / L; preferably, the concentration of the surfactant is 7.5 g / L.

[0007] The concentration of the surfactant and its upper or lower limit can be any value among 5 g / L, 6 g / L, 7 g / L, 7.1 g / L, 7.2 g / L, 7.3 g / L, 7.4 g / L, 7.5 g / L, 7.6 g / L, 7.7 g / L, 7.8 g / L, 7.9 g / L, 8 g / L, 9 g / L, 10 g / L, 11 g / L, 12 g / L, 13 g / L, 14 g / L, and 15 g / L.

[0008] Further, the molar ratio of zinc nitrate to sodium molybdate is (0.5-3):1; preferably, the molar ratio of zinc nitrate to sodium molybdate is 1:1.

[0009] The molar ratio of zinc nitrate to sodium molybdate and its upper or lower limit range can be any value among 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 2:1, and 3:1.

[0010] Further, the molar concentration of zinc nitrate is 0.1-0.5 mol / L; preferably, the molar concentration of zinc nitrate is 0.1 mol / L.

[0011] The molar concentration of zinc nitrate and its upper or lower limit can be any value among 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, and 0.5 mol / L.

[0012] Further, the molar concentration of sodium molybdate is 0.1-0.5 mol / L; preferably, the molar concentration of sodium molybdate is 0.1 mol / L.

[0013] The molar concentration of sodium molybdate and its upper or lower limit can be any value among 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, and 0.5 mol / L.

[0014] Furthermore, the reaction conditions for the hydrothermal method are a pH value of 6-8 and a reaction temperature of 180℃-200℃ for 12-36 h; preferably, a pH value of 7 and a reaction temperature of 190℃ for 24 h.

[0015] pH can be controlled using pH adjusters.

[0016] In a preferred embodiment, the pH adjuster is ethylenediamine, and the concentration of ethylenediamine, calculated as a volume percentage, can be 50%. Those skilled in the art can also use other pH adjusters for pH control, as long as pH control can be achieved without affecting the synthesis of zinc molybdate.

[0017] Furthermore, the preparation method includes the following steps: Step 1: Add the surfactant to the zinc nitrate solution, stir to dissolve, and obtain a zinc nitrate solution containing the surfactant; Step 2: While stirring continuously, add sodium molybdate solution dropwise to zinc nitrate solution containing surfactant to obtain a suspension; Step 3: Prepare zinc molybdate from the suspension using a hydrothermal method.

[0018] In a preferred embodiment, the preparation method includes the following steps: Step 1: Add the surfactant to a 0.1-0.5 mol / L zinc nitrate solution at a dosage of 5-15 g / L, stir to dissolve, and obtain a zinc nitrate solution containing the surfactant; the surfactant is selected from one or more of sodium dodecylbenzenesulfonate, polyoxyethylene polyoxypropylene block copolymer, and polyacrylamide; Step 2: Under continuous stirring, add 0.1-0.5 mol / L sodium molybdate solution dropwise to zinc nitrate solution containing surfactant, wherein the molar ratio of zinc nitrate to sodium molybdate is (1-5):1, to obtain a suspension; Step 3: Prepare zinc molybdate from the suspension using a hydrothermal method. The hydrothermal reaction conditions are pH 6-8 and reaction at 180℃-200℃ for 12-36 h.

[0019] In a preferred embodiment, the preparation method includes the following steps: Step 1: Add the surfactant at a rate of 15 g / L to a 0.2 mol / L zinc nitrate solution, stir to dissolve, and obtain a zinc nitrate solution containing the surfactant; the surfactant is selected from one or more of sodium dodecylbenzenesulfonate, polyoxyethylene-polyoxypropylene block copolymer, and polyacrylamide; Step 2: Under continuous stirring, add 0.2 mol / L sodium molybdate solution dropwise to zinc nitrate solution containing surfactant, wherein the molar ratio of zinc nitrate to sodium molybdate is 1:1, to obtain a suspension. The final concentration of surfactant in the suspension is 7.5 g / L, the final concentration of zinc nitrate is 0.1 mol / L, and the final concentration of sodium molybdate is mol / L. Step 3: Adjust the pH of the suspension to 7 using ethylenediamine and stir for 2 hours; Step 4: Prepare zinc molybdate from the suspension using a hydrothermal method. The hydrothermal reaction conditions are 190℃ for 24 hours.

[0020] Preferably, the method may further include washing and drying steps to obtain solid ZnMoO4.

[0021] Those skilled in the art will understand that, unless otherwise specified, the stirring can be carried out at room temperature, and the stirring speed can be adjusted according to the actual situation, as long as the solute can be dissolved.

[0022] In a preferred embodiment, the solvent of the reaction solution (zinc nitrate solution, sodium molybdate solution) is water.

[0023] On the other hand, this application also provides zinc molybdate prepared by the preparation method described above.

[0024] On the other hand, this application also provides the preparation method described herein or the application of the zinc molybdate described herein in preventing metal corrosion.

[0025] Preferably, the metal includes steel, iron, aluminum, magnesium, copper, zinc, and their alloys.

[0026] Preferably, the corrosion includes salt corrosion.

[0027] More preferably, the salt is sodium chloride.

[0028] In a preferred embodiment, a 3.5 wt% NaCl solution is used. Those skilled in the art will recognize that this coating can prevent corrosion from other types of salts.

[0029] In a preferred embodiment, the metal refers to steel, and the chemical composition of the steel includes iron, carbon, silicon, manganese, phosphorus, sulfur, and copper.

[0030] On the other hand, this application also provides a coating for preventing metal corrosion, the coating containing the zinc molybdate described above.

[0031] Preferably, the coating further includes epoxy resin E20 (EP).

[0032] Those skilled in the art can also use other commonly used substrates to prepare the above coatings, such as polyurethane resins (PU), acrylic resins, and alkyd resins.

[0033] Preferably, the metal includes steel, iron, aluminum, magnesium, copper, zinc, and their alloys.

[0034] In a preferred embodiment, the metal refers to steel, and the chemical composition of the steel includes iron, carbon, silicon, manganese, phosphorus, sulfur, and copper; preferably, the chemical composition of the steel includes 98% iron, 0.2% carbon, 0.3% silicon, 0.5% manganese, 0.06% phosphorus, 0.04% sulfur, 0.3% copper, and 0.6% other components.

[0035] On the other hand, this application also provides a method for preparing the coating, comprising: mixing the zinc molybdate with a substrate evenly, adding a curing agent and stirring to obtain a composite coating.

[0036] Preferably, the matrix is ​​epoxy resin E20 (EP).

[0037] Preferably, the curing agent is a polyamide curing agent.

[0038] Preferably, the mass ratio of zinc molybdate, matrix, and curing agent is 0.1-1:6:1; more preferably, 0.56:6:1.

[0039] Preferably, the stirring time is 10-30 min; more preferably, 15 min.

[0040] Preferably, the method includes: mixing the zinc molybdate with the matrix evenly, adding a curing agent and stirring for 10-30 minutes to obtain a composite coating.

[0041] Preferably, the coating thickness is 20-70 μm. The present invention has the following beneficial effects: 1. In this application, for the first time, sodium dodecylbenzenesulfonate (SDBS), polyoxyethylene polyoxypropylene block copolymer (F-68), and polyacrylamide (PAM) were used to prepare novel zinc molybdates with different morphologies based on a hydrothermal method.

[0042] 2. In this application, the above-mentioned novel zinc molybdate was introduced into epoxy resin as a functional filler to prepare a composite anti-corrosion coating. It was found that the prepared anti-corrosion coating has better long-term anti-corrosion performance, which provides a theoretical basis and experimental foundation for the development of efficient and controllable zinc molybdate-based anti-corrosion fillers. Attached Figure Description

[0043] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of zinc molybdate sample preparation. Detailed Implementation

[0044] To more clearly illustrate the overall concept of this application, a detailed description is provided below with reference to the accompanying drawings and embodiments. Numerous specific details are set forth in the following description to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described to avoid confusion with the invention.

[0045] Before further describing specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terminology used in the embodiments of the present invention is for describing specific embodiments and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the respective manufacturers.

[0046] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0047] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description of this invention, any prior art methods, apparatus, and materials similar to or equivalent to those described, apparatus, and materials in the embodiments of this invention may be used to implement the present invention.

[0048] Unless otherwise specified, in the following embodiments, reagents or instruments whose manufacturers are not indicated are all conventional products that can be purchased commercially.

[0049] Unless otherwise stated, the experimental methods, detection methods, and preparation methods disclosed in this invention all employ conventional techniques in analytical chemistry and related fields.

[0050] In addition, the "water" mentioned in this invention includes any feasible water that can be used in the art, such as deionized water, distilled water, ion-exchanged water, double-distilled water, high-purity water, and purified water.

[0051] In the following embodiments, unless otherwise specified, % means wt%, i.e., weight percentage.

[0052] The reagents required in the following examples are shown in Table 1. All reagents can be used directly for product preparation without secondary purification or refining.

[0053] Table 1 Main reagents used in the experiment reagents Chemical formula Manufacturer Zinc nitrate hexahydrate <![CDATA[Zn(NO3)2·6H2O]]> Shanghai Titan Technology Co., Ltd. Sodium molybdate <![CDATA[Na2MoO4]]> Shanghai McLean Biochemical Technology Co., Ltd. ethylenediamine <![CDATA[C2H8N2]]> Sinopharm Chemical Reagent Co., Ltd. Sodium dodecylbenzenesulfonate (SDBS) <![CDATA[CHNaO3S]]> Sinopharm Chemical Reagent Co., Ltd. Polyoxyethylene-polyoxypropylene block copolymer F-68 <![CDATA[HO(C2H4O) x ·(C3H6O) y ·(C2H4O) z H]]> Sinopharm Chemical Reagent Co., Ltd. Polyacrylamide (PAM) <![CDATA[(C3H5NO) n ]]> Sinopharm Chemical Reagent Co., Ltd. Urea <![CDATA[CH4N2O]]> Shanghai Lingfeng Chemical Reagent Company ethanol <![CDATA[C2H5OH]]> Sinopharm Chemical Reagent Co., Ltd. Epoxy Resin E20 <![CDATA[(C 11 H 12 O3)N]]> Guodu Chemical (Kunshan) Co., Ltd. Polyamide curing agent <![CDATA[C5H 11 N3OR]]> Guodu Chemical (Kunshan) Co., Ltd. The instruments required in the following embodiments are shown in Table 2.

[0054] Table 2. Instruments required for the experiment name Specification Manufacturer Electronic analytical balance PL4001 Mettler Toledo (Shanghai) Co., Ltd. Magnetic stirrer 85-1 Shanghai Yuejin Medical Devices Co., Ltd. Electric constant temperature drying oven GZX-GF-MBS Shanghai Yuejin Medical Devices Co., Ltd. Medical centrifuge H1850 Hunan Xiangyi Laboratory Instrument Development Co., Ltd. Dual-control grinding and polishing machine Fpol Suzhou Fermat Automation Technology Co., Ltd. Field emission scanning electron microscope (SEM) Hitachi-S-4800 Hitachi Manufacturing Co., Ltd. X-ray diffractometer (XRD) Shimadzu XD-3A Shimadzu Corporation Fourier Transmission Infrared Spectrometer (FT-IR) Shimadzu, IR Prestige-21 Shimadzu Corporation Ultraviolet-Vis spectrophotometer (UV-vis) Shimadzu, UV-2600 Shimadzu Corporation Zeta Potential Analyzer FZT500A1 type Beckman Coulter, Germany Electrochemical workstation Zahner-Elektrik IM6e Zahner Electrochemicals, Germany X-ray electron spectroscopy (XPS) K-Alpha Thermo Fisher Scientific China Specific surface area and pore size analyzer JW-BK100C Beijing Jingwei Gaobo Instrument Co., Ltd. Contact angle measuring instrument FCA2000A Shanghai Aifeisi Precision Instruments Co., Ltd. Example 1: Preparation of Zinc Molybdate In this embodiment, zinc molybdate (ZnMoO4) was synthesized via an activator-assisted hydrothermal method. Details are as follows: Preparation of zinc nitrate solution: Weigh 59.502 g of zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and dissolve it in 900 mL of ultrapure water. Stir thoroughly on a magnetic stirrer until completely dissolved. Transfer the dissolved solution to a 1000 mL volumetric flask. Wash the beaker and stir bar several times with a small amount of ultrapure water, transferring the washings to the volumetric flask as well. Finally, dilute to the mark and mix well to obtain a zinc nitrate solution (concentration: 0.2000 mol / L).

[0055] Preparation of sodium molybdate solution: Weigh 41.184 g of sodium molybdate (Na₂MoO₄) and dissolve it in 900 mL of ultrapure water. Stir thoroughly on a magnetic stirrer until completely dissolved. Transfer the dissolved solution to a 1000 mL volumetric flask. Wash the beaker and stir bar several times with a small amount of ultrapure water, transferring the washings to the volumetric flask as well. Finally, dilute to the mark and mix well to obtain a sodium molybdate solution (concentration: 0.2000 mol / L).

[0056] Preparation of zinc molybdate (ZnMoO4): 20 mL of zinc nitrate solution and 20 mL of sodium molybdate solution were placed in two beakers respectively. While stirring continuously, the sodium molybdate solution was added dropwise to the zinc nitrate solution to obtain a suspension. This suspension was then passed through ethylenediamine solution (V... EDA :V 水 The pH of the suspension was adjusted to 7 using a 1:1 ratio, and the suspension was continuously stirred for 2 h. The suspension was then transferred to a polytetrafluoroethylene hydrothermal reactor and maintained at 190 °C for 24 h. Finally, the resulting precipitate was washed and dried to obtain solid ZnMoO4, named ZM.

[0057] Preparation of surfactant-induced zinc molybdate (ZnMoO4): 20 mL of zinc nitrate solution and 20 mL of sodium molybdate solution were placed in two beakers respectively. 0.3 g of surfactant (F-68, SDBS, or PAM) was added to each beaker, and the mixture was stirred until the surfactant was fully dissolved. While continuing to stir, the sodium molybdate solution was added dropwise to the zinc nitrate solution containing the surfactant to obtain a suspension. This suspension was then passed through an ethylenediamine solution (V... EDA :V 水 The pH of the suspension was adjusted to 7 using a 1:1 ratio, and the suspension was continuously stirred for 2 h. This suspension was then transferred to a polytetrafluoroethylene hydrothermal reactor and maintained at 190 °C for 24 h. Finally, the resulting precipitate was washed and dried to obtain solid ZnMoO4, which were named FZM (zinc molybdate induced by surfactant F-68), SZM (zinc molybdate induced by surfactant SDBS), and PZM (zinc molybdate induced by surfactant PAM), respectively. The preparation mechanism diagrams for all samples are shown below. Figure 1 As shown.

[0058] Material characterization: X-ray powder diffraction (XRD, Shimadzu XD-3A) was used to analyze the crystal structure, and scanning electron microscopy (SEM, Hitachi-S-4800) was used to observe the microstructure. The results are as follows: Figure 1 As shown, Figure 1 The top image shows the microstructure of ZM, and the bottom image, from left to right, shows the microstructures of FZM, SZM, and PZM, respectively. Example 2 Preparation of anti-corrosion coating Steel with dimensions of 40 mm × 10 mm × 5 mm was selected as the base material. The chemical composition of the base material is shown in Table 3. The surface of the steel was successively polished using 180 grit, 360 grit, and 600 grit silicon carbide sandpaper until the surface was smooth and flat, free of defects such as oxide scale, rust, and scratches. After polishing, the surface was cleaned with anhydrous ethanol and dried for later use.

[0059] 0.56 g of the zinc molybdate sample (ZM, FZM, SZM, or PZM) prepared in Example 1 and 6.00 g of epoxy resin E20 (EP) were weighed and placed in a glass beaker. The mixture was stirred with a magnetic stirrer for 3 h until the zinc molybdate sample was uniformly dispersed in the epoxy resin matrix without significant agglomeration. Then, 1.00 g of polyamide curing agent was added to the system, and stirring was continued for 15 min to ensure thorough mixing of the curing agent and epoxy resin, resulting in a uniform and stable composite coating. Using a dip-coating technique, the composite coating was uniformly applied to the pretreated steel surface, forming a film in one step (approximately 50 μm thick). The steel was then transferred to a horizontal platform and cured at room temperature for 7 days. After complete curing, the composite coating sample was obtained for corrosion resistance and electrochemical testing.

[0060] Table 3 Chemical composition of steel Fe C Si Mn P S Cu other Quality Score % 98.00 0.20 0.30 0.50 0.06 0.04 0.30 0.60 The corrosion protection performance of the composite coating was evaluated using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PVP) testing. EIS is considered one of the most effective methods for assessing the corrosion resistance of protective coatings, allowing for multi-cycle study of coating corrosion behavior and is a non-destructive testing method. All tests were performed using an IM6e electrochemical workstation in a standard three-electrode system. A saturated calomel electrode (SCE) was used as the reference electrode, carbon steel substrates coated with different composite coatings (ZM, FZM, SZM, or PZM) were used as the working electrode, and a platinum electrode was used as the auxiliary electrode. Before testing, the carbon steel substrates coated with the anti-corrosion coating were immersed in a 3.5 wt% NaCl solution to a depth of approximately 10 mm, with test time points set at 6 h, 24 h, 48 h, and 72 h. The EIS test frequency range was 0.1 Hz to 100 kHz, and a sinusoidal perturbation signal with an amplitude of 10 mV was applied. The potential range for the electrodynamic polarization curve scan was -1.20 V to 0 V (vs. SCE), and the scan rate was 10 mV·s. -1To reduce random errors in electrochemical testing and ensure the reliability and accuracy of experimental data, each sample underwent three parallel tests. The control group consisted of a pure epoxy resin coating without fillers, with all other operating procedures remaining the same. The diameter of the capacitor arc represents the magnitude of the impedance and is directly proportional to the corrosion resistance of the pigment. A larger diameter indicates higher resistance and better corrosion resistance; therefore, the corrosion resistance of the coating can be determined by fitting the Nyquist plot of the coating using an equivalent circuit. The results are shown in Table 4.

[0061] Table 4 shows the impedance modulus obtained by fitting the Nyquist plot of the coating using the equivalent circuit. Group <![CDATA[6 h | Z | 0.1 (kohm cm 2 )]]> <![CDATA[24 h | Z |0.1 (kohm cm 2 )]]> <![CDATA[48 h | Z | 0.1 (kohm cm 2 )]]> <![CDATA[72 h | Z | 0.1 (kohm cm 2 )]]> ZM 35.83 15.68 11.47 8.62 FZM 42.38 21.56 14.65 11.15 SZM 47.46 29.50 19.54 17.43 PZM 29.07 15.08 10.02 7.98 control group 23.52 9.78 5.54 4.28 In summary, all different composite coatings (ZM, FZM, SZM or PZM) have corrosion resistance. The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for producing zinc molybdate, characterized by, The preparation method includes: mixing zinc nitrate, sodium molybdate, and a surfactant, and preparing zinc molybdate by hydrothermal method; the surfactant is selected from one or more of sodium dodecylbenzenesulfonate, polyoxyethylene-polyoxypropylene block copolymer, and polyacrylamide.

2. The production method according to claim 1, characterized by, The concentration of the surfactant is 5-15 g / L.

3. The preparation method according to claim 1, characterized in that, The molar ratio of zinc nitrate to sodium molybdate is (0.5-3):1; preferably, the molar ratio of zinc nitrate to sodium molybdate is 1:

1.

4. The production method according to claim 1, characterized by, The molar concentration of zinc nitrate is 0.1-0.5 mol / L.

5. The preparation method according to claim 1, characterized in that, The molar concentration of sodium molybdate is 0.1-0.5 mol / L.

6. The preparation method according to claim 1, characterized in that, The hydrothermal reaction conditions are pH 6-8, reaction at 180℃-200℃ for 12-36 h; preferably, pH 7, reaction at 190℃ for 24 h.

7. The preparation method according to claim 1, characterized in that, The preparation method includes the following steps: Step 1: Add the surfactant to the zinc nitrate solution, stir to dissolve, and obtain a zinc nitrate solution containing the surfactant; Step 2: While stirring continuously, add sodium molybdate solution dropwise to zinc nitrate solution containing surfactant to obtain a suspension; Step 3: Prepare zinc molybdate from the suspension using a hydrothermal method.

8. Zinc molybdate prepared by any one of the preparation methods described in claims 1-7.

9. The preparation method as described in any one of claims 1-7 or the application of zinc molybdate as described in claim 8 in preventing metal corrosion.

10. A coating for preventing metal corrosion, characterized in that, The coating contains zinc molybdate as described in claim 8.

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