Alkalized titanium carbide-based composite corrosion inhibitor, and preparation method and application thereof

Abstract

The application provides a kind of alkali carbonization titanium-based composite corrosion inhibitor and its preparation method and application, belong to the technical field of stimulus response self-repairing coating, the preparation method of composite corrosion inhibitor includes: first etching titanium carbide aluminum by chemical etching method to obtain titanium carbide two-dimensional material, then the alkali treatment is carried out to the titanium carbide two-dimensional material, then the alkali carbonization titanium carbide two-dimensional material is intercalated by corrosion inhibitor cation, and the alkali carbonization titanium-based composite corrosion inhibitor is obtained, the composite corrosion inhibitor can be used to prepare self-repairing coating, the physical shielding effect of Ti3C2 two-dimensional material in composite corrosion inhibitor and the synergistic corrosion prevention effect between Zn 2+ And Ce 3+ Improve the corrosion resistance and service life of self-repairing coating.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of stimuli-responsive self-healing coating, and particularly relates to a titanium carbide-based composite corrosion inhibitor as well as a preparation method and application thereof. BACKGROUND

[0002] Equipment and facilities serving in marine environment, especially ships and offshore platforms, suffer from serious corrosion problems. Organic coatings are widely used in the corrosion protection of metals due to their wide application conditions, simple construction and economic effectiveness. However, defects such as cracks, micropores and cracks may occur during film formation, transportation and use, which reduces the protective performance of the coating barrier and allows O2, H2O, Cl - and other corrosive media to penetrate and cause localized corrosion at the defects, affecting the service life of the metal substrate.

[0003] To improve the corrosion resistance of the coating and prolong the service life of the coating, some two-dimensional materials such as montmorillonite, hydrotalcite and graphene are usually used as coating fillers to improve the physical shielding performance of the coating, or corrosion inhibitors are introduced into the coating to endow the coating with certain self-healing performance. Kamalon Rajitha et al. added graphene oxide-based materials (GO-AT / EP and GO-ANT / EP) into an epoxy coating system, and the results showed that the coating with the composite material exhibited good corrosion resistance compared with the pure epoxy coating.

[0004] Ti3C2 is a new type of graphene-like two-dimensional layered material, and the formation of a labyrinth structure in the coating filled with Ti3C2 can enhance the shielding effect of the coating. Compared with graphene, Ti3C2 has good dispersibility and compatibility, and can be easily functionalized and modified. Ti3C2 is usually prepared by removing the Al layer of Ti3AlC2 by etching with HF, and the obtained Ti3C2 sheet surface is rich in -F, -OH and =O functional groups, and the whole shows negative electrification, so metal cations (Zn 2+ , Ce 3+ , etc.) with corrosion inhibition effect can be further modified on the surface of Ti3C2, thereby endowing the coating with certain self-healing performance. However, there are still problems such as low adsorption amount of metal cations, fast release rate and poor corrosion inhibition performance. SUMMARY

[0005] To solve the above technical problems, the application provides a titanium carbide-based composite corrosion inhibitor as well as a preparation method and application thereof. The titanium carbide-based composite corrosion inhibitor can be used to prepare a self-healing coating. In the self-healing coating, Ti3C2 two-dimensional material is used as a filler to improve the physical shielding performance, and Zn 2+ and Ce 3+The synergistic corrosion inhibition effect of the alkali-treated titanium carbide-based composite inhibitor improves the corrosion resistance thereof, and the alkalization treatment improves the loading amount and controlled release performance of Ti3C2 two-dimensional material for cationic corrosion inhibitor Zn 2+ and Ce 3+ , so that the long-term release of the corrosion inhibitor is achieved.

[0006] To achieve the above object, the application provides a preparation method of an alkali-treated titanium carbide-based composite inhibitor, which comprises the following steps: etching titanium aluminum carbide (Ti3AlC2) by using a chemical etching method to obtain titanium carbide (Ti3C2) two-dimensional material, performing alkalization treatment on the titanium carbide two-dimensional material, and then intercalating alkali-treated titanium carbide two-dimensional material with different corrosion inhibitor cations to obtain the alkali-treated titanium carbide-based composite inhibitor.

[0007] The application increases the adsorption sites on the surface of Ti3C2 two-dimensional material by alkalization treatment, so as to improve the adsorption amount of the corrosion inhibitor and the controlled release ability of metal cations, and different cationic corrosion inhibitors are adsorbed on the surface of the two-dimensional material, so that the corrosion resistance of the composite coating is improved by the synergistic effect of the corrosion inhibitors and the physical shielding effect of the two-dimensional Ti3C2, and the composite coating is endowed with certain self-repairing performance.

[0008] Further, in the preparation method of the alkali-treated titanium carbide-based composite inhibitor, the method for etching Ti3AlC2 to obtain Ti3C2 two-dimensional material by using a chemical etching method is as follows: Ti3AlC2 is added into hydrofluoric acid (HF), and etching reaction is carried out at 20-40 ℃ for 12-48 h; the lower layer precipitate is taken out after washing with water until pH>6, and freeze-drying is performed to obtain the Ti3C2 two-dimensional material; preferably, 1 g of Ti3AlC2 is added into 10-30 mL of HF with a mass fraction of 20-50%, etching reaction is carried out at 20-40 ℃ for 12-48 h, and then the lower layer precipitate is taken out after centrifugal washing with deionized water until pH>6, and freeze-drying is performed to obtain the Ti3C2 two-dimensional material.

[0009] Further, in the preparation method of the alkali-treated titanium carbide-based composite inhibitor, the alkalization treatment method is as follows: the titanium carbide two-dimensional material is added into an alkali solution, alkalization treatment is performed for 8-48 h, magnetic stirring is performed, centrifugal washing is performed, the lower layer precipitate is taken out and washed with water until neutral, and freeze-drying is performed to obtain the alkali-treated Ti3C2 two-dimensional material; preferably, the Ti3C2 two-dimensional material is added into 50-100 mL of 1-3 M KOH solution for alkalization treatment for 8-48 h, magnetic stirring is performed, then the lower layer precipitate is taken out and washed with deionized water until neutral, and freeze-drying is performed to obtain the alkali-treated Ti3C2 two-dimensional material, which is denoted as Alk-Ti3C2.

[0010] Further, in the preparation method of the alkali-treated titanium carbide-based composite inhibitor, the different corrosion inhibitor cations are Zn 2+ and Ce 3+ . Through the synergistic effect of Zn2+ and Ce 3+ The synergistic effect of two different corrosion inhibitors and the physical shielding effect of two-dimensional Ti3C2 together improve the corrosion resistance of the composite coating and endow the composite coating with certain self-repairing performance.

[0011] Further, the molar mass ratio of Zn 2+ and Ce 3+ is (1-2):(1-2), preferably Zn 2+ :Ce 3+ = 2:1, 1:1 or 1:2.

[0012] Further, in the preparation method of the alkali titanocarbide-based composite corrosion inhibitor, the method for intercalating the alkali titanocarbide two-dimensional material with corrosion inhibitor cations is as follows: adding the alkali titanocarbide two-dimensional material into a salt solution containing different corrosion inhibitor cations, magnetic stirring, centrifugation, water washing of the precipitate, freeze-drying; preferably dispersing Alk-Ti3C2 into a salt solution containing different proportions of corrosion inhibitor cations with a concentration of 1-3 M, adsorbing and loading Zn 2+ and Ce 3+ by magnetic stirring, centrifugation, deionized water washing of the lower precipitate, freeze-drying, and grinding into powder to obtain the alkali titanocarbide-based composite corrosion inhibitor, denoted as Alk-Ti3C2-Zn 2+ / Ce 3+ .

[0013] An alkali titanocarbide-based composite corrosion inhibitor prepared by the above method.

[0014] Use of the alkali titanocarbide-based composite corrosion inhibitor in the preparation of an alkali titanocarbide-based self-repairing coating.

[0015] A method for preparing an alkali titanocarbide-based self-repairing coating using the above alkali titanocarbide-based composite corrosion inhibitor, comprising the following steps:

[0016] Adding the alkali titanocarbide-based composite corrosion inhibitor into an epoxy resin, stirring and ultrasonicating, adding an epoxy curing agent, stirring uniformly, standing, obtaining a composite coating, and coating the composite coating on the surface of a substrate to obtain an alkali titanocarbide-based self-repairing coating.

[0017] Further, in the method for preparing the alkali titanocarbide-based self-repairing coating, the mass ratio of the epoxy resin to the epoxy curing agent is 2:1.

[0018] Further, in the method for preparing the alkali titanocarbide-based self-repairing coating, the epoxy curing agent is a polyamide curing agent.

[0019] Further, in the method for preparing the alkali titanocarbide-based self-repairing coating, the epoxy resin is an E-44 epoxy resin.

[0020] Further, a method for preparing an alkali titan carbide-based self-repairing coating using the above alkali titan carbide-based composite corrosion inhibitor, comprising the following steps:

[0021] adding Alk-Ti3C2-Zn 2+ / Ce 3+ into the E-44 epoxy resin (the amount of Alk-Ti3C2-Zn 2+ / Ce 3+ added is 0.2-2wt% of the E-44 epoxy resin), stirring for 3-5min and ultrasonicating for 5-10min, adding a polyamide curing agent, stirring uniformly, standing for defoaming, to obtain a composite coating, coating the composite coating on the surface of a metal substrate (such as a steel plate), to obtain an alkali titan carbide-based self-repairing coating.

[0022] In the present application:

[0023] (1) The unique sheet structure of Ti3C2 two-dimensional material can form a “labyrinth effect” in the epoxy resin coating to effectively isolate the corrosion medium, prolong the diffusion path of the corrosion medium, and significantly improve the number and size of micropores in the coating, enhancing the denseness of the coating;

[0024] (2) When water, oxygen and Cl - - etc. corrosion medium penetrates into the coating / filler interface, the hydrotalcite nanosheet can capture the invading Cl - in the coating by ion exchange, reducing the concentration of free migrating Cl - in the coating.

[0025] (3) When the coating is accidentally damaged, local acidification causes the ZnAlCe hydrotalcite dispersed in the damaged area to dissolve, accelerating the release of the internally loaded MoO4 2- corrosion inhibitor, which can be adsorbed on the local micro-corrosion defect by iron ion chelation to prevent further corrosion reaction, thereby achieving an active protection function; on the other hand, the dissolution of the hydrotalcite layer also releases more corrosion-inhibiting Zn 2+ and Ce 3+ , generating a hydroxide precipitate film in the cathode area, promoting the formation of a more stable and dense protective film on the metal surface, protecting the metal substrate from corrosion.

[0026] Compared with the prior art, the present application has the following advantages and technical effects:

[0027] The present application adjusts the interlayer spacing and functional group type and quantity of Ti3C2 two-dimensional material by alkali reaction to improve the dispersibility and compatibility of Ti3C2 two-dimensional material as a filler in the coating, and improve its physical shielding performance as a corrosion-resistant filler; on the other hand, the cationic corrosion inhibitors Zn 2+ and Ce3+ Loading the coating onto the surface of Ti3C2 lamellars, the synergistic effect of two different corrosion inhibitors enhances its corrosion resistance and imparts a certain degree of self-healing properties. Through the alkalization treatment of Ti3C2, not only are more -OH groups introduced onto the Ti3C2 surface, expanding its interlayer spacing and thus improving the dispersibility of the two-dimensional Ti3C2 material in the coating, but the introduction of more active sites also improves the Zn... 2+ and Ce 3+ The increased loading capacity of the alkali-modified titanium carbide-based composite corrosion inhibitor enhances the interaction between Ti3C2 and the cationic corrosion inhibitor, resulting in excellent controlled-release performance. In summary, this invention utilizes the physical shielding effect of the two-dimensional Ti3C2 material in the composite corrosion inhibitor and the Zn... 2+ and Ce 3+ The synergistic anti-corrosion effect between the components jointly improves the corrosion resistance and service life of the self-healing coating. Attached Figure Description

[0028] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0029] Figure 1 It is Ti3C2, Alk-Ti3C2 and Alk-Ti3C2-Zn in Example 3 2+ / Ce 3+ The dispersion results in E-44 epoxy resin after 2 hours, from left to right, are Ti3C2, Alk-Ti3C2, and Alk-Ti3C2-Zn. 2+ / Ce 3+ ;

[0030] Figure 2 It is Ti3C2, Alk-Ti3C2 and Alk-Ti3C2-Zn in Example 3 2+ / Ce 3+ The dispersion results in E-44 epoxy resin after 240 hours, from left to right, are Ti3C2, Alk-Ti3C2, and Alk-Ti3C2-Zn. 2+ / Ce 3+ ;

[0031] Figure 3 It is Ti3C2-Zn 2+ / Ce 3+ Zn at different release times in water 2+ and Ce 3+ The release curve;

[0032] Figure 4 It is Alk-Ti3C2-Zn in Example 3 2+ / Ce3+ Zn release profile in water at different release times 2+ and Ce 3+ release profile;

[0033] Figure 5 is an electrochemical impedance spectrogram of Q235 steel coated with epoxy varnish coating in 3.5 wt% NaCl solution;

[0034] Figure 6 is an electrochemical impedance spectrogram of Q235 steel with composite coating of Alk-Ti3C2-Zn 2+ / Ce 3+ in Example 3 in 3.5 wt% NaCl solution;

[0035] Figure 7 is an electrochemical impedance spectrogram and corrosion morphology of scribe coating of epoxy varnish coating and composite coating containing Alk-Ti3C2-Zn 2+ / Ce 3+ in Example 3 in 3.5 wt% NaCl solution, where (a) is an electrochemical impedance spectrogram of scribe coating of epoxy varnish coating in 3.5 wt% NaCl solution, (b) is an electrochemical impedance spectrogram of scribe coating of composite coating containing Alk-Ti3C2-Zn 2+ / Ce 3+ in Example 3 in 3.5 wt% NaCl solution, (c) is a corrosion morphology of scribe coating of epoxy varnish coating in 3.5 wt% NaCl solution, (d) is a corrosion morphology of scribe coating of composite coating containing Alk-Ti3C2-Zn 2+ / Ce 3+ in Example 3 in 3.5 wt% NaCl solution. DETAILED DESCRIPTION

[0036] Various exemplary embodiments of the present application will now be described in detail, without intent to limit the application, which is only limited by the claims. Understanding that these embodiments are given as examples only, the present application is intended to encompass any and all implementation forms of various aspects, features, and combinations of features and aspects disclosed herein.

[0037] It should be understood that the terms used herein are merely descriptive, but that the application should not be limited thereto. In addition, for numerical ranges recited in the application, it is intended that every

[0038] Unless otherwise indicated, all technical and scientific terms have the same meaning as those one of ordinary skill in the art of the disclosure would understand. Although preferred methods and materials are described, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure. All documents mentioned herein are incorporated by reference to disclose and describe in further detail the methods and / or materials associated with the documents. In the case of conflict between the present specification and any incorporated document, the present specification controls.

[0039] Many modifications and variations of the present disclosure described in the detailed description of the disclosure can be made by those of ordinary skill in the art without departing from the scope or spirit of the disclosure. Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure. The specification and examples of the disclosure are illustrative only.

[0040] As used herein, the terms "comprises", "comprising", "includes", "including", "has", "having", and the like are open-ended terms that are intended to permit but not limit the inclusion of elements or the number of elements, as well as the possibility that one or more other elements can be added or otherwise included.

[0041] The raw materials of the present disclosure are all purchased, and typically but not limited to Ti3AlC2 in each embodiment is purchased from Shanghai Bumi Applied Material Technology Co., Ltd., HF is purchased from Tianjin Damao Chemical Reagent Factory, KOH solution is purchased from Tianjin Damao Chemical Reagent Factory, E-44 epoxy resin is purchased from Anhui Linghu Paint Co., Ltd., and polyamide 651 curing agent is purchased from Anhui Linghu Paint Co., Ltd.

[0042] Example 1

[0043] (1) 1 g of Ti3AlC2 was added to 10 mL of 20% mass fraction HF, and etching reaction was carried out at 25°C for 12 h, and then centrifugal washing was carried out several times with deionized water until pH > 6, and the lower layer precipitate was taken out and freeze-dried to obtain Ti3C2 two-dimensional material;

[0044] (2) The Ti3C2 two-dimensional material obtained above was added to 50 mL of 1M KOH solution for alkalization treatment for 8 h, and magnetic stirring was carried out, and then centrifugal washing was carried out with deionized water until neutral, and freeze-drying was carried out to obtain alkalized Ti3C2 two-dimensional material, which was recorded as Alk-Ti3C2;

[0045] (3) Alk-Ti3C2 was dispersed into a mixed salt solution of zinc nitrate and cerium nitrate (Zn 2+ ∶Ce 3+ = 2:1, molar mass ratio, the same below) with a concentration of 1M, and magnetic stirring was carried out on Zn 2+ and Ce 3+adsorption, centrifugation, deionized water washing of the lower precipitate, freeze-drying, and grinding into powder to obtain the alkali-carbide titanium-based composite corrosion inhibitor Alk-Ti3C2-Zn 2+ / Ce 3+ .

[0046] The interlayer-loaded Zn 2+ , Ce 3+ of Alk-Ti3C2-Zn 2+ / Ce 3+ composite corrosion inhibitor obtained above is added to E-44 epoxy resin (the addition amount of Alk-Ti3C2-Zn 2+ / Ce 3+ is 0.2wt% of E-44 epoxy resin), stirred for 3min and ultrasonicated for 5min to ensure uniform dispersion of the composite corrosion inhibitor; and polyamide 651 curing agent is added thereto, the mass ratio of E-44 epoxy resin to epoxy curing agent is 2:1, stirred uniformly, and left to stand for 30min to eliminate air bubbles, to obtain a composite coating, which is coated on a Q235 steel plate.

[0047] Example 2

[0048] (1) 1g of Ti3AlC2 is added to 30mL of 25wt% HF, and etching reaction is carried out at 25℃ for 24h. Then, the lower precipitate is obtained by centrifugal washing with deionized water until pH>6, and freeze-drying to obtain Ti3C2 two-dimensional material;

[0049] (2) The Ti3C2 two-dimensional material obtained above is added to 100mL of 2M NaOH solution for alkali treatment for 16h, and magnetic stirring is carried out, then the lower precipitate is obtained by centrifugal washing with deionized water until neutral, and freeze-drying to obtain alkali Ti3C2 two-dimensional material, which is denoted as Alk-Ti3C2.

[0050] (3) The Alk-Ti3C2 is dispersed into a mixed salt solution of zinc nitrate and cerium nitrate with a concentration of 2M (Zn 2+ :Ce 3+ =1:1), and magnetic stirring is carried out to adsorb and load Zn 2+ and Ce 3+ , centrifugation, deionized water washing of the lower precipitate, freeze-drying, and grinding into powder to obtain the alkali-carbide titanium-based composite corrosion inhibitor Alk-Ti3C2-Zn 2+ / Ce 3+ .

[0051] The interlayer-loaded Zn 2+ , Ce 3+ of Alk-Ti3C2-Zn 2+ / Ce 3+A composite corrosion inhibitor was added to E-44 epoxy resin (Alk-Ti3C2-Zn). 2+ / Ce 3+ The amount of added material is 1.0 wt% of E-44 epoxy resin. Stir for 3 minutes and sonicate for 5 minutes to ensure uniform dispersion of the composite corrosion inhibitor. Add polyamide 651 curing agent to it. The mass ratio of E-44 epoxy resin to epoxy curing agent is 2:1. Stir evenly and let stand for 30 minutes to eliminate air bubbles. The composite coating is then applied to Q235 steel plate.

[0052] Example 3

[0053] (1) 1 g of Ti3AlC2 was added to 30 mL of 30% HF and etched at 20 °C for 36 h. Afterwards, the mixture was washed several times with deionized water until the pH was > 6. The lower precipitate was then taken and freeze-dried to obtain the two-dimensional Ti3C2 material.

[0054] (2) The Ti3C2 two-dimensional material obtained above was added to 50 mL of 1 M KOH solution for alkalization treatment for 24 h. After magnetic stirring, the precipitate was removed by centrifugation and washed with deionized water until neutral. The alkalized Ti3C2 two-dimensional material was obtained by freeze drying and denoted as Alk-Ti3C2.

[0055] (3) Disperse Alk-Ti3C2 in a 2M solution of a mixed salt of zinc nitrate and cerium nitrate (Zn 2+ ∶Ce 3+ In a ratio of 1:2, magnetic stirring is used for Zn 2+ and Ce 3+ Adsorption loading, centrifugation, washing of the lower precipitate with deionized water, freeze-drying, and grinding into powder yields the alkalized titanium carbide-based composite corrosion inhibitor Alk-Ti3C2-Zn. 2+ / Ce 3+ .

[0056] The obtained interlayer load Zn 2+ Ce 3+ Alk-Ti3C2-Zn 2+ / Ce 3+ A composite corrosion inhibitor was added to E-44 epoxy resin (Alk-Ti3C2-Zn). 2+ / Ce 3+ The amount of added material is 0.5 wt% of E-44 epoxy resin. Stir for 5 min and sonicate for 10 min to ensure uniform dispersion of the composite corrosion inhibitor. Add polyamide 651 curing agent to it. The mass ratio of E-44 epoxy resin to epoxy curing agent is 2:1. Stir evenly and let stand for 30 min to eliminate air bubbles to obtain the composite coating. Apply it to Q235 steel plate.

[0057] Example 4

[0058] (1) 1 g of Ti3AlC2 was added to 25 mL of 40% mass fraction HF, and etching reaction was carried out at 40°C for 48 h, and then centrifugal washing was carried out several times with deionized water until pH > 6, the lower layer precipitate was taken out and freeze-dried to obtain Ti3C2 two-dimensional material;

[0059] (2) The Ti3C2 two-dimensional material obtained above was added to 80 mL of 1.5 M NaOH solution for alkalization treatment for 48 h, and magnetic stirring was carried out, and then centrifugal separation was carried out to take out the lower layer precipitate and wash with deionized water until neutral, and freeze-drying was carried out to obtain alkalized Ti3C2 two-dimensional material, which was recorded as Alk-Ti3C2;

[0060] (3) Alk-Ti3C2 was dispersed into a mixed salt solution of 1 M zinc nitrate and cerium nitrate (Zn 2+ ∶ Ce 3+ = 1:1), and magnetic stirring was carried out for adsorption and loading of Zn 2+ and Ce 3+ , centrifugal separation was carried out, the lower layer precipitate was washed with deionized water, freeze-drying was carried out, and grinding into powder was carried out to obtain alkalized titanium carbide-based composite corrosion inhibitor Alk-Ti3C2-Zn 2+ / Ce 3+ .

[0061] The obtained Alk-Ti3C2-Zn 2+ / Ce 3+ composite corrosion inhibitor loaded with Zn 2+ and Ce 3+ between layers was added to E-44 epoxy resin (the addition amount of Alk-Ti3C2-Zn 2+ / Ce 3+ was 2.0 wt% of E-44 epoxy resin), stirring was carried out for 3 min and ultrasonic treatment was carried out for 10 min to ensure uniform dispersion of the composite corrosion inhibitor; and polyamide 651 curing agent was added thereto, the mass ratio of E-44 epoxy resin to epoxy curing agent was 2:1, stirring was carried out uniformly, and standing was carried out for 30 min to eliminate bubbles, and a composite coating was obtained, which was coated on a Q235 steel plate.

[0062] Example 5

[0063] (1) 1 g of Ti3AlC2 was added to 25 mL of 40% mass fraction HF, and etching reaction was carried out at 40°C for 48 h, and then centrifugal washing was carried out several times with deionized water until pH > 6, the lower layer precipitate was taken out and freeze-dried to obtain Ti3C2 two-dimensional material;

[0064] (2) The Ti3C2 two-dimensional material obtained above is added to 60 mL of 2.0 M NaOH solution for alkalization treatment for 30 h, magnetic stirring, and then centrifugation is performed to take the lower precipitate and wash with deionized water until neutral, and freeze-drying to obtain the alkalized Ti3C2 two-dimensional material, denoted as Alk-Ti3C2;

[0065] (3) The Alk-Ti3C2 is dispersed into a mixed salt solution of zinc nitrate and cerium nitrate with a concentration of 1 M (Zn 2+ : Ce 3+ = 1:1), magnetic stirring is performed for adsorption and loading of Zn 2+ and Ce 3+ , centrifugation, deionized water washing of the lower precipitate, freeze-drying, and grinding into powder to obtain the alkalized titanium carbide-based composite corrosion inhibitor Alk-Ti3C2-Zn 2+ / Ce 3+ .

[0066] The obtained Alk-Ti3C2-Zn 2+ / Ce 3+ composite corrosion inhibitor loaded with Zn 2+ and Ce 3+ between layers is added to E-44 epoxy resin (the addition amount of Alk-Ti3C2-Zn 2+ / Ce 3+ is 1.0 wt% of the E-44 epoxy resin), stirring for 3 min and ultrasonic treatment for 10 min to ensure uniform dispersion of the composite corrosion inhibitor; and a polyamide 651 curing agent is added thereto, the mass ratio of the E-44 epoxy resin to the epoxy curing agent being 2:1, stirring is uniformly performed, and standing for 30 min to eliminate air bubbles, to obtain a composite coating, which is coated on a Q235 steel plate.

[0067] As a comparison, a titanium carbide-based composite corrosion inhibitor Ti3C2-Zn 2+ / Ce 3+ without alkalization treatment is prepared and its performance is investigated, and the preparation method of the Ti3C2-Zn 2+ / Ce 3+ is as follows:

[0068] (1) 1 g of Ti3AlC2 is added to 30 mL of 30% HF by mass fraction for etching reaction at 20℃ for 36 h. Then, deionized water is used for centrifugal washing several times until pH > 6, the lower precipitate is taken out and freeze-dried to obtain the Ti3C2 two-dimensional material;

[0069] (2) The Ti3C2 two-dimensional material is dispersed into a mixed salt solution of zinc nitrate and cerium nitrate with a concentration of 2 M (Zn 2+ : Ce 3+ = 1:2), magnetic stirring is performed for adsorption and loading of Zn 2+ and Ce 3+The adsorption loading, centrifugation, deionized water washing of the lower precipitate, freeze-drying, and grinding into powder were performed to obtain the unalkalized titanium carbide-based composite corrosion inhibitor Ti3C2-Zn 2+ / Ce 3+ .

[0070] Ti3C2, Alk-Ti3C2, Ti3C2-Zn 2+ / Ce 3+ and Alk-Ti3C2-Zn 2+ / Ce 3+ Performance test of Ti3C2, Alk-Ti3C2, and Alk-Ti3C2-Zn (for example, prepared in Example 3):

[0071] (1) Dispersion performance

[0072] A certain amount of Ti3C2, Alk-Ti3C2, and Alk-Ti3C2-Zn 2+ / Ce 3+ was weighed, respectively, and added to E-44 epoxy resin, wherein the addition amount of each sample was 0.5wt% of the E-44 epoxy resin. The three samples were dispersed in the E-44 epoxy resin by ultrasonic treatment, and the dispersion of the three in the epoxy resin slurry at different times was investigated, and the results are shown in Figure 1 and Figure 2 It can be seen from Figure 1 and Figure 2 that ultrasonic treatment can make the three samples uniformly dispersed in the epoxy resin slurry within a short time (2h). However, when the standing time reaches 240h, precipitation can be observed at the bottom in the epoxy slurry added with Ti3C2, while no obvious precipitates are observed in the epoxy resin slurries added with Alk-Ti3C2 and Alk-Ti3C2-Zn 2+ / Ce 3+ , which indicates that the dispersion of Ti3C2 is poor among the three. This is because the alkalization treatment of Ti3C2 can introduce more -OH on its surface, improving the dispersion of the material in the epoxy resin slurry.

[0073] (2) Release performance

[0074] 0.1g of Ti3C2-Zn 2+ / Ce 3+ and Alk-Ti3C2-Zn 2+ / Ce 3+The samples were added to 100 mL distilled water, respectively, and 5 mL of the release medium was taken at appropriate time (determined by experience combined with test data to determine the subsequent sampling interval. Generally, the release is faster in the early stage (within 60 min), and the test is performed once every 10 min or so. Subsequently, as the release progresses, the sampling interval is extended, and the test is performed once every 30 min or 1 h or 3 h until the release is complete or no longer released (the curve appears flat)). 5 mL of distilled water was added to the release medium. The release medium at different times was determined by ultraviolet-visible spectrophotometer and ICP, respectively, to determine the concentrations of Zn 2+ and Ce 3+ , and the results are shown in Figure 3 and Figure 4 . It can be seen from Figure 3 that for Ti3C2-Zn 2+ / Ce 3+ without alkalization treatment, the sustained release of Zn 2+ and Ce 3+ can be maintained for about 400 min, but there is a significant burst release phenomenon in the early stage of release (about 50% for Zn 2+ and about 38% for Ce 3+ ). The total loading amount of the cationic corrosion inhibitor Zn 2+ and Ce 3+ is about 0.25%.

[0075] It can be seen from Figure 4 that for the Alk-Ti3C2-Zn 2+ / Ce 3+ sample after alkalization treatment, the release amount of Zn 2+ and Ce 3+ is zero in the early stage of immersion, and no burst release phenomenon occurs. With the increase of immersion time, the released Zn 2+ and Ce 3+ contents also increase, and the release rate slows down at about 1600 min, basically reaching the release equilibrium. In addition, after alkalization treatment, the loading amount of Zn 2+ and Ce 3+ is about 0.73%, which is about 3 times that before treatment.

[0076] It can be seen that the Alk-Ti3C2-Zn 2+ / Ce 3+ sample obtained by alkalization treatment not only can increase the loading amount of the corrosion inhibitor cation, but also has good controlled release performance to ensure the controllable release and long-term effectiveness of the composite corrosion inhibitor in the use process.

[0077] (3) Corrosion resistance

[0078] In order to investigate the corrosion resistance of the Alk-Ti3C2-Zn2+ / Ce 3+ The corrosion prevention and enhancement effect of the epoxy resin coating was prepared by coating epoxy varnish coating (referring to directly mixing E-44 epoxy resin and polyamide 651 curing agent according to a mass ratio of 2:1, uniformly stirring, and standing for 30 min to eliminate bubbles, thereby obtaining the epoxy varnish coating, which was coated on the Q235 steel plate) and the composite coating sample of Example 3 adding 0.5 wt% Alk-Ti3C2-Zn 2+ / Ce 3+ , and the results are shown in Figure 5 and Figure 6 . For the epoxy varnish coating, the impedance value in the low frequency region is about 10 9 Ω·cm 2 at the initial stage of immersion (5 days), and the Bode plot presents one time constant, indicating that the epoxy varnish coating plays an effective shielding protection role for the Q235 carbon steel substrate at the initial stage of immersion Figure 5 . As the immersion time continues to extend, the coating impedance value continuously decreases, and when the epoxy varnish coating is immersed for 20 days, a second time constant appears, and the coating impedance value decreases to about 10 7 Ω·cm 2 , which indicates that the 3.5% NaCl solution has gradually penetrated the coating and contacted the metal substrate, and the carbon steel begins to corrode. As the coating immersion time extends to 30 days, the impedance value decreases to 1.6 x 10 6 Ω·cm 2 . The above results show that the corrosion prevention effect of the coating for the Q235 carbon steel substrate continuously decreases as the immersion time extends.

[0079] As can be seen from Figure 6 , for the composite coating added with Alk-Ti3C2-Zn 2+ / Ce 3+ , the impedance value in the low frequency region is about 10 10 Ω·cm 2 at the initial stage of immersion, which is significantly higher than that of the epoxy varnish coating, indicating that the introduction of Alk-Ti3C2-Zn 2+ / Ce 3+ improves the physical shielding performance of the coating. As the immersion time extends, the impedance film value at the low frequency does not obviously decrease, and the impedance film value is maintained at about 10 9 Ω·cm 2 above throughout the immersion stage, and a second time constant is not observed, indicating that the metal does not corrode.

[0080] Therefore, the addition of Alk-Ti3C2-Zn 2+ / Ce 3+The composite coating can significantly improve the corrosion resistance and extend the service life of the coating. This is mainly attributed to the Al-Ti3C2-Zn composite coating. 2+ / Ce 3+ The small size effect of Ti3C2 two-dimensional material in composite materials can fill internal defects in the coating, improving its density. Simultaneously, its two-dimensional structure can create a labyrinth effect within the coating, extending the diffusion path of corrosive media. Furthermore, the cationic corrosion inhibitor Zn in the composite material... 2+ and Ce 3+ It can be gradually released into the coating, working synergistically to improve the coating's anti-corrosion performance.

[0081] (4) Self-healing performance

[0082] To investigate the self-healing performance of the composite coating, scratches were artificially created on the composite corrosion inhibitor prepared in step (3) of Example 3, and a scratch test was conducted. The results are as follows: Figure 7 As shown. From Figure 7 It can be observed that the epoxy varnish coating has a low impedance value, at 10. 3 Ω·cm 2 about( Figure 7 (a) and Alk-Ti3C2-Zn added 2+ / Ce 3+ The impedance value of the composite coating is in the range of 10. 4 Ω·cm 2 The area around the blank coating is significantly higher than that of the uncoated coating. Figure 7 (b) may contain the corrosion inhibitor cationic Zn. 2+ and Ce 3+ It is gradually released into the damaged area of ​​the coating, forming an inhibitory film on the carbon steel surface and playing a protective role.

[0083] Furthermore, after soaking in a 3.5 wt% NaCl solution for 72 hours, the epoxy varnish coating was scratched. Figure 7 The presence of significant yellow rust in the scratched area (c) indicates severe corrosion of the exposed Q235 carbon steel. The addition of Alk-Ti3C2-Zn further supports this finding. 2+ / Ce 3+ Composite coating ( Figure 7 The cross-cut immersion area in (d) showed almost no corrosion products, further proving that Zn... 2 + and Ce 3+ The coating adsorbs and forms a corrosion-inhibiting film on the carbon steel surface, effectively suppressing the corrosion reaction and giving the coating a certain degree of self-healing properties.

[0084] The above merely describes preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for preparing an alkalized titanium carbide-based composite corrosion inhibitor, characterized in that, First, titanium aluminum carbide is etched using chemical etching to obtain two-dimensional titanium carbide material. Then, the two-dimensional titanium carbide material is alkalized. Then, different cation inhibitors are used to intercalate the alkalized two-dimensional titanium carbide material to obtain an alkalized titanium carbide-based composite corrosion inhibitor. The method for obtaining two-dimensional titanium carbide materials by etching titanium aluminum carbide using chemical etching is as follows: titanium aluminum carbide is added to hydrofluoric acid and etched at 20-40℃ for 12-48h. After washing with water until pH>6, the lower precipitate is removed and freeze-dried to obtain the two-dimensional titanium carbide materials. The alkalization treatment method is as follows: the two-dimensional titanium carbide material is added to an alkaline solution, alkalized for 8-48 hours, magnetically stirred, centrifuged, the lower precipitate is removed and washed with water until neutral, and freeze-dried to obtain the alkalized two-dimensional titanium carbide material. The different corrosion inhibitors have Zn as their cation. 2+ and Ce 3+ Zn 2+ and Ce 3+ The molar mass ratio is (1-2):(1-2); The method for intercalating alkalized titanium carbide two-dimensional material using different corrosion inhibitor cations is as follows: the alkalized titanium carbide two-dimensional material is added to a salt solution containing different corrosion inhibitor cations, magnetically stirred, centrifuged, the precipitate is washed with water, and freeze-dried.

2. An alkalized titanium carbide-based composite corrosion inhibitor, characterized in that, It is prepared by the method described in claim 1.

3. The application of the alkalized titanium carbide-based composite corrosion inhibitor according to claim 1 in the preparation of alkalized titanium carbide-based self-healing coatings.

4. A method for preparing an alkali-based titanium carbide-based self-healing coating using the alkali-based titanium carbide composite corrosion inhibitor according to claim 2, characterized in that, Includes the following steps: An alkalized titanium carbide-based composite corrosion inhibitor is added to an epoxy resin, stirred and sonicated, an epoxy curing agent is added, stirred evenly, and allowed to stand to obtain a composite coating. The composite coating is then applied to the surface of a substrate to obtain an alkalized titanium carbide-based self-healing coating.

5. The method for preparing an alkali-modified titanium carbide-based self-healing coating according to claim 4, characterized in that, The mass ratio of the epoxy resin to the epoxy curing agent is 2:

1.

6. The method for preparing an alkali-modified titanium carbide-based self-healing coating according to claim 5, characterized in that, The epoxy curing agent is a polyamide curing agent.

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