阅读说明：本技术 一种有机无机复合插层水滑石基阻锈剂及制备方法及应用 (Organic-inorganic composite intercalated hydrotalcite-based rust inhibitor and preparation method and application thereof ) 是由 熊传胜 金祖权 于泳 张小影 王鹏刚 李宁 李哲 徐翔波 于 2020-08-05 设计创作，主要内容包括：本发明涉及一种有机无机复合插层水滑石基阻锈剂及制备方法及应用。包括水滑石类化合物、维生素C阴离子、亚硝酸根,维生素C阴离子和亚硝酸根分别替换水滑石类化合物的层间阴离子,维生素阴离子为失去氢离子的维生素。制备过程为先将水滑石进行焙烧,然后分别与亚硝酸根、维生素C进行离子交换反应。得到有机无机复合插层水滑石基阻锈剂。本发明的阻锈剂具有较好的抗氯离子侵蚀的作用,同时具有抗锈时间长的优点。(The invention relates to an organic-inorganic composite intercalated hydrotalcite-based rust inhibitor and a preparation method and application thereof. Comprises hydrotalcite compounds, vitamin C anions and nitrite, wherein the vitamin C anions and the nitrite are respectively used for replacing interlayer anions of the hydrotalcite compounds, and the vitamin anions are vitamins without hydrogen ions. The preparation process includes roasting hydrotalcite and ion exchange reaction with nitrite and vitamin C separately. Obtaining the organic-inorganic composite intercalated hydrotalcite base rust inhibitor. The rust inhibitor has the advantages of good effect of resisting chloride ion corrosion and long rust resisting time.)

1. An organic-inorganic composite intercalation hydrotalcite base rust inhibitor is characterized in that: comprises hydrotalcite compounds, vitamin C anions and nitrite, wherein the vitamin C anions and the nitrite are respectively used for replacing interlayer anions of the hydrotalcite compounds, and the vitamin C anions are vitamin C without hydrogen ions.

2. The organic-inorganic composite intercalated hydrotalcite-based rust inhibitor according to claim 1, characterized in that: the hydrotalcite is Mg-Al, Zn-Al, Ni-Al, Co-Al, Mn-Al, Co-Cr, and the anion is CO₃ ^2-(ii) a Mg-Al hydrotalcite is preferred.

3. The method for preparing the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor as claimed in any one of claims 1 to 2, wherein: the method comprises the steps of roasting hydrotalcite to obtain roasted hydrotalcite, carrying out ion exchange reaction on the roasted hydrotalcite and nitrite to obtain hydrotalcite grafted with nitrite, and carrying out ion exchange reaction on the hydrotalcite grafted with nitrite and vitamin C to obtain the composite intercalated hydrotalcite rust inhibitor.

4. The method for preparing the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor according to claim 3, wherein the method comprises the following steps: the roasting temperature is 450-550 ℃, and the roasting time is 2-5 h; preferably 500 ℃;

or, the nitrite is NaNO₂、KNO₂、Ca(NO₂)₂。

5. The method for preparing the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor according to claim 3, wherein the method comprises the following steps: the process of roasting hydrotalcite and nitrite to carry out ion exchange reaction is as follows: mixing the roasted hydrotalcite, nitrite and water in an inert atmosphere at room temperature, carrying out suction filtration, washing a filter cake, and drying to obtain the hydrotalcite grafted with nitrite;

preferably, the mixing reaction time of the calcined hydrotalcite and the nitrite with water is 10-15 h; preferably 12-13 h;

preferably, the washing utilizes deionized water and absolute ethyl alcohol;

preferably, the drying temperature is 60-70 ℃, and the drying time is 10-15 h;

preferably, calcined hydrotalcite and NaNO₂The mass ratio of (A) to (B) is 3: 0.5-1.5.

6. The method for preparing the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor according to claim 3, wherein the method comprises the following steps: the process of carrying out the ion exchange reaction of the nitrite-grafted hydrotalcite and the vitamin C is as follows: inert atmosphereUnder the condition of enclosing, mixing the vitamin alkali solution and the hydrotalcite grafted with nitrite for ionization reaction, wherein the vitamin alkali solution is the mixed solution of vitamin C and alkali, carrying out solid-liquid separation after the reaction, and drying to obtain the composite intercalated hydrotalcite rust inhibitor Mg-Al-NO₂ ^--VC；

Preferably, the mass ratio of the nitrite grafted hydrotalcite to the vitamin C is 1-5: 1;

preferably, the vitamin alkali solution is prepared by the following steps: mixing vitamin C, alkali and water to react under inert atmosphere to obtain the vitamin alkali solution.

7. The method for preparing the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor according to claim 6, wherein the method comprises the following steps: the molar ratio of the vitamin C to the NaOH is 1: 1-2; preferably 1: 1;

or mixing vitamin C and alkali with water for reaction for 20-40 min; more preferably 25 to 35 min.

8. The method for preparing the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor according to claim 1, wherein the method comprises the following steps: the conditions for the reaction of the vitamin alkali solution and the hydrotalcite grafted with the nitrite are as follows: the pH value is 8-12, the room temperature and the reaction time is 45-55 h; preferably, the reaction time is 48-52 h.

9. Use of the organic-inorganic composite intercalated hydrotalcite based corrosion inhibitor according to any of claims 1-2 in the field of corrosion protection of concrete reinforcements.

10. The application method of the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor in corrosion prevention of concrete reinforcements, which is characterized by comprising the following steps: the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor is doped into concrete according to 0.5-5% of the mass of the cementing material.

Technical Field

The invention belongs to the technical field of concrete rust inhibitors, and particularly relates to an organic-inorganic composite intercalated hydrotalcite-based rust inhibitor, and a preparation method and application thereof.

Background

The information in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.

The reinforced concrete structure has the advantages of economy, high strength, easy acquisition and the like, and is widely applied to various global projects. However, the problems of durability have been a major factor hindering the further development and application of reinforced concrete technology, due to the invasion of various factors in the environment. Among them, the corrosion of steel bars caused by the corrosion of chloride ions is the primary cause of the failure of concrete structures. Especially, in coastal areas or western saline soil areas, early damage and failure of engineering structures caused by corrosion of reinforced concrete frequently occur, and huge damage is caused to national economy and lives and properties of people. Therefore, the development of efficient and environmentally friendly corrosion protection systems is critical to ensure long-term operation of concrete structure infrastructures in harsh corrosive environments.

The addition of a steel bar rust inhibitor into concrete has proved to be a measure for effectively delaying the corrosion of steel bars, and has been applied to a certain extent in engineering at present. The currently widely used rust inhibitor can be divided into inorganic rust inhibitors and organic rust inhibitors, wherein the inorganic rust inhibitors comprise nitrite, phosphate and molybdate, the nitrite is most widely used, the rust inhibitor has excellent rust inhibiting effect, but the rust inhibitor can exert the rust inhibiting effect only when the concentration is high enough, otherwise, the corrosion of reinforcing steel bars is accelerated, and in addition, the nitrite has stronger carcinogenicity, so the rust inhibitor has great harm to the environment and human health, and does not meet the environmental protection requirement of the modern society. The organic rust inhibitor is usually an organic compound containing heteroatoms such as N, O, S, and is mainly diffused into concrete in liquid and gaseous forms by utilizing capillary action, and is adsorbed on the surface of a reinforcing steel bar to form a film so as to achieve the rust inhibition effect. However, in practical use, the diffusion and migration of the organic rust inhibitor are greatly influenced by the compactness of concrete, and it is difficult for a relatively dense concrete structure to reach the surface of the steel bar through diffusion and form a sufficient protection concentration. In addition, the traditional organic rust inhibitor only acts on the steel bars, the diffusion of chloride ions is not effectively inhibited, the chloride ions can still diffuse to the surfaces of the steel bars through concrete to cause pitting corrosion, and the protection efficiency of the rust inhibitor is greatly reduced.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide an organic-inorganic composite intercalated hydrotalcite-based rust inhibitor, and a preparation method and application thereof.

In order to solve the technical problems, the technical scheme of the invention is as follows:

in a first aspect, the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor comprises a hydrotalcite compound, vitamin C anions, nitrite, vitamin C anions and Nitrite (NO)^2-) Respectively replacing interlayer anion of hydrotalcite compound, and vitamin C anion is hydrogen ion (H)⁺) Vitamin C of (2).

Vitamin C and nitrite exist between interlayer structures of hydrotalcite, and the coating effect and controllable release of the ion cavities of LDHs on the rust inhibitor are utilized, so that the compactness of the rust inhibitor adsorbed into a film in a steel bar corrosion area can be effectively improved, the adsorption speed of the rust inhibitor on the surface of a steel bar is accelerated along with the increase of the concentration of the rust inhibitor, and the defects in the adsorption film are easily increased and the compactness is easily reduced due to relatively quick adsorption. Through the coating effect and the controllable release of the LDHs cavity on the rust inhibitor, the concentration of the rust inhibitor in the solution can be effectively regulated, the adsorption rate of the rust inhibitor on the surface of the reinforcing steel bar is regulated, and the film forming compactness is improved. Greatly improving the rust resistance efficiency and the protection aging. Vitamin C is an organic rust inhibitor, and nitrite is an inorganic rust inhibitor. The two rust inhibitors act together to improve the function of resisting the corrosion of chloride ions of the reinforcing steel bar.

In a second aspect, the method for preparing the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor comprises the steps of roasting hydrotalcite to obtain roasted hydrotalcite, then carrying out ion exchange reaction on the roasted hydrotalcite and nitrite to obtain hydrotalcite grafted with nitrite, and carrying out ion exchange reaction on the hydrotalcite grafted with nitrite and vitamin C to obtain the composite intercalated hydrotalcite rust inhibitor.

In the invention, hydrotalcite (LDHs) is grafted with organic and inorganic rust-resisting components to realize the functional modification of the LDHs super molecular sub-body, wherein the organic rust-resisting component is vitamin C, and the inorganic rust-resisting component is nitrite. The recognition and exchange of the chloride ions and the rust-resisting groups on the LDHs supermolecular layer is the anion exchange effect between the LDHs supermolecular layers. The dual functions of chloride ion solidification and reinforcing steel bar targeted rust resistance are realized.

In a third aspect, the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor is applied to the field of corrosion prevention of concrete reinforcements.

In a fourth aspect, the application method of the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor in the corrosion prevention of the concrete reinforcement comprises the following steps: the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor is doped into concrete according to 0.5-5% of the mass of the cementing material.

The invention has the beneficial effects that:

compared with the prior art, the organic-inorganic composite intercalated hydrotalcite rust inhibitor provided by the invention fully exerts the synergistic effect of the composite intercalated components, has the advantages of fast effect taking of nitrite, good long-term corrosion protection of vitamin C and environmental protection while exerting the targeted rust inhibition characteristic of the hydrotalcite rust inhibitor, and can reduce the dosage of the nitrite and reduce the environmental pollution. Specifically, the method comprises the following steps:

(1) the performance is excellent: the rust inhibitor prepared by the invention can effectively solidify chloride ions in a concrete environment, fully exerts the advantages of excellent early performance of nitrite and long-acting corrosion prevention and environmental protection of vitamin C, and can provide high-efficiency corrosion inhibition effect in the early stage and in a long term.

(2) The cost is low: the hydrotalcite and sodium nitrite are selected to synthesize raw materials with wide sources and low cost, large-scale commercial use is realized, and the vitamin C is widely existed in various plants and is easy to extract.

(3) The environmental pollution is small: the hydrotalcite has a targeted controlled release effect on the rust inhibitor, so that the loss of the rust inhibitor can be effectively reduced; through the compound intercalation of nitrite and green biological rust inhibitor vitamin C, the mixing amount of nitrite is reduced and the environmental pollution is reduced while the ideal corrosion inhibition effect is maintained.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the invention and not to limit the invention.

FIG. 1 is a synthetic route for a rust inhibitor;

fig. 2 is a scanning electron microscope picture and an energy spectrum surface scanning analysis picture of example 1, wherein a, d are pictures of a magnesium aluminum carbonate type hydrotalcite scanning electrode, b, e are pictures of a calcined hydrotalcite scanning electron microscope, C, f are pictures of a hydrotalcite scanning electron microscope after intercalation of vitamin C, and g is a pictures of an energy spectrum surface scanning analysis of a hydrotalcite after intercalation of vitamin C;

FIG. 3 is a transmission electron micrograph of example 1, wherein a, b, and C are hydrotalcite, calcined hydrotalcite, and hydrotalcite with intercalated vitamin C, respectively;

FIG. 4 is a thermal analysis curve of example 1, wherein a and b are hydrotalcite and hydrotalcite with intercalated vitamin C, respectively.

Detailed Description

It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

In a first aspect, the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor comprises a hydrotalcite compound, vitamin C anions, nitrite, vitamin C anions and Nitrite (NO)^2-) Respectively replacing interlayer anion of hydrotalcite compound, and vitamin C anion is hydrogen ion (H)⁺) Vitamin C of (2).

For example, the traditional rust inhibitor mentioned in the background art is easy to chemically degrade when applied and cannot inhibit the diffusion of chloride ions, so that the technical bottleneck problem of short protection time effect is caused.

In some embodiments of the invention, the hydrotalcite is Mg-Al, Zn-Al, Ni-Al, Co-Al, Mn-Al, Co-Cr and the anion is CO₃ ^2-(ii) a Mg-Al hydrotalcite is preferred. The hydrotalcite compounds (LDHs) introduce the assembly of functional molecules into the three-dimensional dimension of point-surface combination by linear butt joint, and are a new generation flagship material in a supermolecular receptor series. The hydrotalcite in the invention has a stable interlayer structure, grafting of the hydrotalcite, vitamin C and nitrite is realized through ion combination, and the interlayer structure coats the rust-inhibiting group, so that the release of the rust-inhibiting group achieves the slow release effect.

In a second aspect, the method for preparing the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor comprises the steps of roasting hydrotalcite to obtain roasted hydrotalcite, then carrying out ion exchange reaction on the roasted hydrotalcite and nitrite to obtain hydrotalcite grafted with nitrite, and carrying out ion exchange reaction on the hydrotalcite grafted with nitrite and vitamin C to obtain the composite intercalated hydrotalcite rust inhibitor (Mg-Al-NO)₂ ^--VC)。

In some embodiments of the invention, the roasting temperature is 450-; preferably 500 deg.c. In the above temperature range, crystal water between the layered structures of the hydrotalcite is lost by calcination, and hydroxyl groups between the layered structures are shrunk and carbonate groups are decomposed into carbon dioxide. Forming more stable roasted hydrotalcite.

In some embodiments of the invention, the nitrite salt is NaNO₂、KNO₂、Ca(NO₂)₂And the like.

In some embodiments of the present invention, the process of calcining hydrotalcite and nitrite to perform ion exchange reaction is: and (3) mixing the calcined hydrotalcite, nitrite and water in an inert atmosphere at room temperature, carrying out suction filtration, washing a filter cake, and drying to obtain the hydrotalcite grafted with nitrite.

The principle of the process is that nitrite ions are intercalated between the layers of calcined hydrotalcite through self-assembly reaction between nitrite and hydrotalcite layers.

Preferably, the mixing reaction time of the calcined hydrotalcite and the nitrite with water is 10-15 h; preferably 12-13 h. And roasting hydrotalcite and nitrite at room temperature to react in the mixing process. Preferably, the washing utilizes deionized water and absolute ethanol. Preferably, the drying temperature is 60-70 ℃, and the drying time is 10-15 h. And (4) washing to remove the residual unreacted nitrite.

In some embodiments of the invention, the hydrotalcite and NaNO are calcined₂The mass ratio of (A) to (B) is 3: 0.5-1.5. Conditioning calcined hydrotalcite and NaNO₂The mass ratio of (A) to (B) is to control the-NO intercalated in the hydrotalcite₂Content, which is convenient for flexibly carrying out secondary intercalation of organic anions.

In some embodiments of the present invention, the process of ion exchange reaction of the nitrite-grafted hydrotalcite with vitamin C is: mixing a vitamin alkali solution and the hydrotalcite grafted with nitrite to carry out ionization reaction in an inert atmosphere, carrying out solid-liquid separation after the reaction, and drying to obtain the composite intercalated hydrotalcite rust inhibitor Mg-Al-NO₂ ^--VC。

And (3) carrying out self-assembly reaction on the vitamin C anions and the hydrotalcite plate layer grafted with the nitrite. Obtaining the hydrotalcite grafted by nitrite and vitamin together. I.e., a rust inhibitor containing both organic and inorganic rust inhibiting components.

In the present inventionIn some embodiments, the mass ratio of the hydrotalcite grafted with nitrite to the vitamin C is 1-5: 1. By adjusting Mg-Al-NO₂ ^-Adjusting the mass ratio of-NO inserted between hydrotalcite laminate and vitamin C₂And vitamin C anion in proportion to achieve the best initial and long-acting corrosion inhibition effect.

In some embodiments of the invention, the vitamin base solution is prepared by: and mixing vitamin C, NaOH and water to react under an inert atmosphere to obtain the vitamin alkali solution. Vitamin C and alkali are in the solution to ensure that the vitamin C is fully ionized, and vitamin C anions are obtained in the solution.

Preferably, the molar ratio of the vitamin C to the NaOH is 1: 1-2; preferably 1: 1. Since vitamin C molecules contain a plurality of hydroxyl groups, the concentration of NaOH needs to be adjusted to achieve an ideal ionization effect.

Preferably, the mixing reaction time of the vitamin C and the alkali with the water is 20-40 min; more preferably 25 to 35 min.

In some embodiments of the invention, the conditions under which the solution of the vitamin alkali is reacted with the nitrite grafted hydrotalcite are: the pH value is 8-12, the room temperature and the reaction time is 45-55 h; preferably, the reaction time is 48-52 h.

The water used above is water subjected to carbon dioxide removal treatment.

In a third aspect, the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor is applied to the field of corrosion prevention of concrete reinforcements.

In a fourth aspect, the application method of the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor in the corrosion prevention of the concrete reinforcement comprises the following steps: the organic-inorganic composite intercalated hydrotalcite-based rust inhibitor is doped into concrete according to 0.5-5% of the mass of the cementing material.

The invention will be further illustrated by the following examples