CN110142190B

CN110142190B - Self-repairing composite coating and application thereof, anti-corrosion material and preparation method thereof

Info

Publication number: CN110142190B
Application number: CN201910472888.1A
Authority: CN
Inventors: 王彩旗; 崔含蕊
Original assignee: University of Chinese Academy of Sciences
Current assignee: University of Chinese Academy of Sciences
Priority date: 2019-05-31
Filing date: 2019-05-31
Publication date: 2020-09-11
Anticipated expiration: 2039-05-31
Also published as: CN110142190A

Abstract

The invention provides a self-repairing composite coating and application thereof, an anti-corrosion material and a preparation method thereof. The self-healing composite coating comprises: a hydrophobic layer and a hydrophilic layer in contact, wherein the hydrophobic layer comprises a hydrophobic substance; the hydrophilic layer comprises a self-healing layer comprising a hydrophilic species a comprising at least one of dynamic covalent bonds. Compared with the prior art, the invention has the beneficial effects that: the self-repairing composite coating can be applied to the field of corrosion prevention, cannot enable liquid to permeate, and can actively repair the defects of the coating in the preparation and use processes, so that the self-repairing composite coating has the function of corrosion prevention effectively. Furthermore, the liquid of the self-repairing composite coating in the anti-corrosion material can not enter the composite coating to contact with the substrate to corrode the substrate, and the self-repairing composite coating can actively repair the defects of the coating in the preparation and use processes and has excellent biocompatibility.

Description

Self-repairing composite coating and application thereof, anti-corrosion material and preparation method thereof

Technical Field

The invention relates to the technical field of chemical materials and application, in particular to a self-repairing composite coating and application thereof, an anti-corrosion material and a preparation method thereof.

Background

Many materials (such as metal, plastic and the like) in daily life are easy to corrode under the action of the external environment, so that huge loss is brought to national economy. Aiming at the corrosion prevention research of metal, various technologies such as chemical conversion layer, micro-arc oxidation, anodic oxidation, electroplating and the like are adopted to coat an organic, inorganic or polymer coating on the surface of the metal, so that the metal is isolated from a corrosive medium, thereby achieving the purpose of corrosion prevention.

Although the method plays a role in protecting the metal to a certain extent, a plurality of problems still exist in practical use, such as inevitable micropore defects exist in the preparation process of the coating, the coating can not completely prevent the invasion of corrosive liquid, further pitting corrosion occurs at the liquid penetration position to cause stress concentration, and the pitting corrosion pit position is broken, so that the service life of the metal is greatly shortened. The traditional method for compensating the micropore defect is to coat for multiple times, however, the strategy of simply blocking the micropore is not perfect, and multiple coating is easy to cause the coating to be too thick, the adhesive force to be poor and to be peeled off from the metal surface, so that the corrosion of the exposed part is aggravated.

In recent years, scientists find that the asymmetric wettability or asymmetric microstructure of the Janus film can realize the directional permeation of liquid, thereby achieving the purpose of draining or absorbing water. Namely, the hydrophobic layer is arranged on the upper part, and the hydrophilic layer is arranged on the lower part, so that the liquid drops spread on the surface of the Janus film and cannot penetrate, and the characteristic that the liquid cannot penetrate is applied to the corrosion prevention of the material, so that the method has a certain prospect. However, although the introduction of the Janus concept can significantly delay the direct contact between the substrate and the corrosive medium, the passive protection method cannot timely sense the change of the external environment, and if the damage and the crack which may be encountered in the using process of the coating are not timely and effectively repaired, the defects can significantly reduce the adhesion of the coating, so that the corrosion is accelerated, and the service life of the material is shortened.

In the prior art, the self-repairing material can actively repair defects generated by corrosion by means of film-forming substances or chemical bonds responding to the external environment so as to achieve the purpose of corrosion prevention, but the repairing efficiency of the self-repairing material is limited, so that the long-acting protection performance of the whole coating is influenced.

The cited document [1] provides a method for producing an anticorrosive iron-clad film. The method prepares the corrosion inhibitor by the reaction of ascorbic acid and phytic acid, utilizes the characteristics of low toxicity or non-toxicity and low price of the ascorbic acid, has stronger electron donating capability of oxygen atoms in molecules, can form a firm adsorption protective film on the surface of metal, can stably exist under alkaline conditions, and utilizes the mutual contact of phosphate molecules and the surface of a material after being combined with the phytic acid, hydrophobic chains in the molecules are adsorbed on the surface of the material to form a continuous adsorption layer, hydrophilic groups of the adsorption layer face air, and the molecules contain-OH and can form hydrogen bonds with water molecules, and the adsorbed water layer can form a conductive film, so that the conductivity of the surface of the material is enhanced, the static charge accumulation of the surface of the material is reduced, the permeation path of the oxygen molecules to the surface of a matrix is prolonged, the corrosion inhibitor has excellent barrier performance, and the corrosion resistance is improved. But the preparation method is complex, and although the paint has certain anti-corrosion performance, the paint still has micropore defects and can not completely prevent the invasion of corrosive liquid.

Citation [2] provides an anticorrosive coating capable of being automatically repaired in an acidic environment and a method for preparing the same. The self-repairing corrosion protection coating comprises the following parts: 0.5-5 parts of acid-responsive mesoporous silica loaded with corrosion inhibitor and 95-99.5 parts of resin condensate. However, the self-repairable anticorrosive coating can realize self-repairing in an acid environment, corresponding acid cannot be provided in other environments, the supported corrosion inhibitor cannot be released rapidly, a protective film cannot be formed, and corrosion cannot be inhibited.

Therefore, how to construct a protection system really suitable for materials becomes a technical problem to be solved urgently.

Cited document [1 ]: CN108997604A

Cited document [2 ]: CN109504242A

Disclosure of Invention

Problems to be solved by the invention

Aiming at the technical problems in the prior art, the invention firstly provides the application of the self-repairing composite coating in corrosion prevention.

Further, the invention also provides a self-repairing composite coating and an anti-corrosion material comprising the same, wherein the self-repairing composite coating does not allow liquid to permeate and can actively repair damaged positions, so that the self-repairing composite coating effectively plays a role in corrosion prevention.

Further, the invention also provides a preparation method of the anti-corrosion material.

Means for solving the problems

The invention provides an application of a self-repairing composite coating in corrosion prevention, wherein the self-repairing composite coating comprises the following components: hydrophobic and hydrophilic layers in contact, wherein

The hydrophobic layer comprises a hydrophobic substance;

the hydrophilic layer comprises a self-healing layer comprising a hydrophilic species a comprising at least one of dynamic covalent bonds.

The self-repairing composite coating is applied to corrosion prevention, wherein the hydrophilic layer further comprises a transition layer which is in contact with the self-repairing layer; wherein

The transition layer is present between the self-repairing layer and the hydrophobic layer, or the transition layer is present on the side of the self-repairing layer opposite to the hydrophobic layer;

the transition layer includes a hydrophilic substance.

The application of the self-repairing composite coating in corrosion prevention is characterized in that the hydrophobic layer is doped with a corrosion inhibitor, and preferably, the corrosion inhibitor comprises one or a combination of more than two of paeonol, honey, citrus peel and bamboo leaves.

The self-repairing composite coating is applied to corrosion prevention, wherein the surface of the self-repairing composite coating has an irregular structure, and preferably, the irregular structure comprises at least one of a concave structure, a convex structure and a reticular structure.

The self-repairing composite coating is applied to corrosion prevention, wherein the dynamic covalent bond comprises at least one of an amide bond, a disulfide bond, an imine bond and an acylhydrazone bond.

The invention also provides a self-repairing composite coating, wherein the self-repairing composite coating is the self-repairing composite coating as set forth in any one of claims 1-5.

The invention also provides an anti-corrosion material, wherein the anti-corrosion material comprises a substrate and a self-repairing composite coating formed on the surface of the substrate; the self-healing composite coating of claim 6.

The anti-corrosion material is characterized in that the self-repairing composite coating is formed on the surface of the substrate, the hydrophobic layer is in contact with the surface of the substrate, and the hydrophilic layer is arranged on the side, opposite to the substrate, of the hydrophobic layer; or

The hydrophilic layer is in contact with the surface of the substrate, and the hydrophobic layer is arranged on one side, opposite to the substrate, of the hydrophilic layer.

The corrosion-resistant material according to the present invention, wherein the substrate is a surface-treated substrate; preferably, the surface of the substrate has a net structure after the substrate is subjected to surface treatment.

The invention also provides a preparation method of the anti-corrosion material, which comprises the following steps:

preparing a self-repairing layer material by using a hydrophilic substance A;

preparing a hydrophobic material from a hydrophobic substance;

and enabling the self-repairing layer material and the hydrophobic material to alternately form a hydrophilic layer and a hydrophobic layer on the surface of the substrate, wherein the hydrophilic layer comprises the self-repairing layer.

The preparation method of the anti-corrosion material further comprises the steps of preparing a transition layer material by taking a hydrophilic substance;

forming a transition layer between the self-repairing layer and the hydrophobic layer by using the transition layer material; or forming a transition layer on the side, opposite to the hydrophobic layer, of the self-repairing layer by using the transition layer material.

The preparation method according to the present invention, wherein the preparation method further comprises subjecting the substrate to surface treatment; preferably, modifying the surface of the substrate by using a modifier; the modifying agent comprises an acidic solution;

more preferably, the modifier further comprises an alcohol and/or an inorganic salt.

ADVANTAGEOUS EFFECTS OF INVENTION

Compared with the prior art, the invention has the beneficial effects that: the self-repairing composite coating can be applied to the field of corrosion prevention, cannot enable liquid to permeate, and can actively repair the defects of the coating in the preparation and use processes, so that the self-repairing composite coating has the function of corrosion prevention effectively.

Furthermore, the liquid of the self-repairing composite coating in the anti-corrosion material can not enter the composite coating to contact with the substrate to corrode the substrate, and the self-repairing composite coating can actively repair the defects of the coating in the preparation and use processes and has excellent biocompatibility.

Furthermore, the preparation method of the anticorrosive material has the advantages of easily available raw materials, higher safety, easier molding, shorter processing time and higher production efficiency, and is suitable for industrial large-scale production.

Drawings

FIG. 1 is a perspective view of a corrosion-resistant material according to an embodiment of the present invention;

FIG. 2 is a perspective view of the corrosion-resistant material according to the embodiment of the present invention;

FIG. 3 is an electron micrograph of a magnesium ingot of example 2 of the present invention and a corrosion preventing material VIII (Mg-P @ PCL-PGD) of example 3;

FIG. 4 is a schematic illustration of contact angle sizes of different materials of example 1 of the present invention;

FIG. 5 is a graph showing the magnitude of the contact angle of different materials in example 2 and example 3 of the present invention;

FIG. 6 is a schematic diagram of the self-repairing condition of the magnesium ingot and the corrosion protection material VIII (Mg-P @ PCL-PGD) of example 3 in 0 h;

FIG. 7 is a schematic diagram of the self-repairing condition of the magnesium ingot and the corrosion protection material VIII (Mg-P @ PCL-PGD) of example 3 in 72 h;

FIG. 8 is a schematic diagram of the self-repairing condition of the magnesium ingot of the invention and the corrosion protection material VIII (Mg-P @ PCL-PGD) of example 3 at 216 h;

FIG. 9 is a schematic representation of the corrosion self-healing condition at 372h for a magnesium ingot of the present invention and the corrosion protection material VIII of example 3 (Mg-P @ PCL-PGD);

FIG. 10 is a schematic representation of the self-repair of a magnesium ingot of the present invention and the corrosion protection material VIII of example 3 (Mg-P @ PCL-PGD) at 468 h;

fig. 11 is a graph showing the change tendency of the resistance values of different materials at different times in example 2 and example 3 of the present invention.

Description of the reference numerals

1: a substrate; 2: a hydrophobic layer; 3: a hydrophilic layer; 4: self-repairing the composite coating;

31: a self-healing layer; 32: and a transition layer.

Detailed Description

Various exemplary embodiments, features and aspects of the invention will be described in detail below. The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a better understanding of the present invention. It will be understood by those skilled in the art that the present invention may be practiced without some of these specific details. In other instances, methods, means, devices and steps which are well known to those skilled in the art have not been described in detail so as not to obscure the invention.

All units used in the present invention are international standard units unless otherwise stated, and numerical values and numerical ranges appearing in the present invention should be understood to include systematic errors inevitable in industrial production.

As used herein, the terms "substantially", "substantially" and the like shall mean an error of no more than 5% unless otherwise specified.

First embodiment

A first embodiment of the present invention provides a self-healing composite coating 4 and the use of the self-healing composite coating 4 for corrosion protection. As shown in FIG. 1, the self-healing composite coating 4 of the present invention comprises: hydrophobic layer 2 and hydrophilic layer 3 in contact, wherein

The hydrophobic layer 2 comprises a hydrophobic substance;

the hydrophilic layer 3 comprises a self-repairing layer 31, the self-repairing layer 31 comprises a hydrophilic substance A, and the hydrophilic substance A comprises one or a combination of more than two of dynamic covalent bonds.

In a specific embodiment, as shown in fig. 2, the hydrophilic layer 3 further comprises a transition layer 32 in contact with the self-repairing layer 31, wherein the transition layer 32 is present between the self-repairing layer 31 and the hydrophobic layer 2, or the transition layer 32 is present on the side of the self-repairing layer 31 opposite to the hydrophobic layer 2; the transition layer 32 includes a hydrophilic substance.

In the invention, the self-repairing composite coating 4 is formed on the surface of the substrate 1, the hydrophobic layer 2 is in contact with the surface of the substrate 1, and the hydrophilic layer 3 is arranged on the side of the hydrophobic layer 2 opposite to the substrate 1; or

The hydrophilic layer 3 is in contact with the surface of the substrate 1, and the hydrophobic layer 2 is arranged on one side, opposite to the substrate 1, of the hydrophilic layer 3.

The hydrophilic layer 3 and the hydrophobic layer 2 both have good biocompatibility, and the obtained self-repairing composite coating 4 also has excellent biocompatibility and can obtain an excellent anti-corrosion effect.

The self-repairing composite coating 4 prevents liquid from permeating under the combined action of hydrophobic acting force, static pressure and capillary force, thereby achieving the purpose of corrosion resistance. The self-repairing composite coating 4 of the invention can also actively repair the damaged position, thereby realizing double repair of the damaged position. The self-repairing composite coating 4 combines the characteristic that water cannot permeate the coating with the advantage of actively repairing the damaged position, thereby effectively playing a role in corrosion resistance.

The self-repairing composite coating 4 can respond to and complex with ions generated by corrosion and can respond to alkaline conditions generated by corrosion so as to realize self-repairing.

< self-healing composite coating >

The self-healing composite coating 4 of the present invention may be a Janus film with self-healing functionality. The Janus membrane generally refers to a membrane with asymmetric structure or property, the key to distinguish the Janus membrane from the asymmetric membrane is whether the properties of the two sides of the membrane are "opposite", such as hydrophilicity/hydrophobicity or electropositivity/electronegativity, etc., while the asymmetry of the simple structure or composition cannot be called as the Janus membrane. The self-repairing composite coating 4 has two surfaces with different properties, namely has a Janus structure and self-repairing capability, and can play the functions of the Janus structure and the self-repairing capability. The self-repairing composite coating 4 can prevent liquid from permeating under the combined action of hydrophobic acting force, static pressure and capillary force, and further achieves the purpose of corrosion resistance. The hydrophilic layer 3 and the hydrophobic layer 2 in the self-repairing composite coating 4 can have self-repairing capability so as to realize self-repairing, and can be combined with the Janus structure to achieve the purpose of double corrosion resistance.

In the present invention, the self-healing composite coating 4 can be prepared by two methods: asymmetric fabrication, where the Janus structure is formed during film formation, and asymmetric decoration, where the asymmetric decoration is post-modified to obtain the Janus structure.

Asymmetric fabrication is the separate fabrication of two asymmetric structures, which are then bonded together to obtain a Janus structure. For example: the hydrophobic layer 2 and the hydrophilic layer 3 can be prepared by an electrostatic spinning method to obtain a Janus structure; the hydrophobic layer 2 and the hydrophilic layer 3 may also be prepared by depositing the hydrophilic component and the hydrophobic component onto the substrate by means of direct coating to obtain a Janus structure.

In addition, asymmetric modification can also be achieved by a single-sided modification method to obtain Janus structure. For example: the self-repairing composite coating 4 with Janus structure can be obtained by ultraviolet irradiation, chemical vapor deposition, co-deposition and the like. The preparation method of the hydrophilic layer 3 and the hydrophobic layer 2 of the self-repairing composite coating 4 is not particularly limited, as long as the corresponding Janus structure with the hydrophilic layer 3 and the hydrophobic layer 2 can be obtained.

Further, the surface and/or the interior of the self-repairing composite coating 4 of the invention is provided with a plurality of pore structures, and the pore diameter of the pore structures is 0.1-1000 nm; in the self-repairing composite coating 4, the hydrophobic layer 2 and the hydrophilic layer 3 can be tightly combined together, so that the purposes of self-repairing and corrosion prevention are achieved. In the present invention, the surface of the self-healing composite coating 4 may also have a plurality of irregular structures. The irregular structure may be, for example: at least one of a concave structure, a convex structure, a mesh structure, and the like.

< hydrophobic layer >

In the present invention, the water-repellent layer 2 contains a hydrophobic substance, and the hydrophobic substance may be a substance containing a hydrophobic group and having hydrophobicity, for example: the chemical compound may be a chemical compound containing a C10-C20 hydrocarbon group, a chemical compound containing a hydrocarbon group such as an aryl group, an ester group, an ether group, an amine group, and an amide group, or a chemical compound containing a hydrocarbon group having a double bond; chemical substances containing ester groups, etc.; preferably, the hydrophobic substance may comprise an aliphatic polyester, such as: polycaprolactone, polyglycolide, polylactide, polyglycolide-lactide, and the like.

Preferably, a corrosion inhibitor may be doped in the hydrophobic layer 2 of the present invention to further improve the corrosion protection. In particular, the doped corrosion inhibitor may comprise an inorganic corrosion inhibitor and/or an organic corrosion inhibitor. The inorganic corrosion inhibitor mainly comprises chromate, nitrite, silicate, molybdate, tungstate, polyphosphate, zinc salt and the like; the organic corrosion inhibitor mainly comprises some heterocyclic compounds containing nitrogen oxide compounds, such as phosphonic acid (salt), phosphonic carboxylic acid, sulfenyl benzothiazole, benzotriazole, sulfonated lignin and the like. In addition, the organic corrosion inhibitor can also be a polymer-based corrosion inhibitor. For example: may be a polymer chemical including some oligomers of polyethylene, phosphonocarboxylic acid copolymer (POCA), and polyaspartic acid.

In the invention, the corrosion inhibitor can comprise one or more of paeonol, honey, orange peel and bamboo leaves.

In the invention, the hydrophobic layer 2 can be contacted with the surface of the substrate 1, and the hydrophilic layer 3 is arranged on the side of the hydrophobic layer 2 opposite to the substrate 1; the hydrophilic layer 3 can also be contacted with the surface of the substrate 1, and the hydrophobic layer 2 is arranged on the side of the hydrophilic layer 3 opposite to the substrate 1; preferably, the hydrophobic layer 2 is in contact with the surface of the substrate 1, and the hydrophilic layer 3 is arranged on the side of the hydrophobic layer 2 opposite to the substrate 1, so that the purposes of self-repairing and corrosion resistance can be effectively achieved.

< hydrophilic layer >

The hydrophilic layer 3 of the present invention contains a self-repairing layer 31. The self-repairing layer 31 contains a hydrophilic substance a having a hydrophilic group and at least one of dynamic covalent bonds. The hydrophilic substance a may be a hydrophilic substance directly containing at least one of the dynamic covalent bonds, or may be a hydrophilic substance that is generated to contain at least one of the dynamic covalent bonds to form the self-repairing layer 31 when the self-repairing layer 31 is prepared.

Preferably, the dynamic covalent bond includes at least one of an amide bond, a disulfide bond, an imine bond, and an acylhydrazone bond.

For example, an amide bond is formed by reacting a hydrophilic substance containing a carboxyl group with a hydrophilic substance containing an amino group to form the self-repairing layer 31. For example: the self-repairing layer 31 containing amido bond can be formed by soaking in hydrophilic substance containing carboxyl and then in hydrophilic substance containing amino; at this time, the self-repair layer may actually be a two-layer structure.

Further, as shown in fig. 2, the hydrophilic layer 3 of the present invention further includes a transition layer 32 in contact with the self-repairing layer, where the transition layer 32 is present between the self-repairing layer 31 and the hydrophobic layer 2, or the transition layer 32 is present on a side of the self-repairing layer 31 opposite to the hydrophobic layer 2, and preferably, the transition layer 32 is present between the self-repairing layer 31 and the hydrophobic layer 2.

The transition layer 32 contains hydrophilic substances; the hydrophilic substance may be a substance having a hydrophilic group and having hydrophilicity, such as: can be chemical substances containing carboxyl, sulfonic acid group, sulfuric acid group, phosphoric acid group, amino group, quaternary ammonium group, ether group, hydroxyl group and the like; specifically, in the present invention, the hydrophilic substance may include one or a combination of two or more of polyacrylic acid, polyurethane, polydopamine, polyvinyl alcohol, and the like.

The hydrophilic layer of the present invention may also be doped with a suitable amount of corrosion inhibitor. The corrosion inhibitor is the corrosion inhibitor disclosed by the invention. The hydrophilic substance a of the present invention may be obtained by modifying with a hydrophilic substance.

Second embodiment

A second embodiment of the present invention provides an anticorrosive material. The anti-corrosion material comprises a substrate 1 and a self-repairing composite coating 4 formed on the surface of the substrate 1; the self-healing composite coating 4 is the self-healing composite coating 4 of the first embodiment.

Generally speaking, in the invention, the self-repairing composite coating 4 can be directly formed on the surface of the substrate 1, thereby playing the roles of corrosion prevention and self-repairing; the self-repairing composite coating 4 can also be prepared in advance and then arranged on the surface of the substrate 1, so that the anti-corrosion effect is achieved.

< substrate >

In the present invention, the self-repairing composite coating 4 may be formed on the surface of the substrate 1, wherein the substrate 1 includes one or a combination of two or more of metal, ceramic, plastic and glass, wherein the metal may be any one of gold, silver, copper, magnesium, iron, aluminum, etc., and the plastic may be polyethylene, polypropylene, etc.

In the present invention, the surface of the substrate 1 may be modified by physical or chemical methods, for example, a modifying agent may be used to perform surface treatment on the substrate, and after the surface treatment, the surface of the substrate 1 may have a network structure, so as to be better integrated with the self-repairing composite coating 4.

The self-repairing composite coating 4 is formed on the surface of the substrate 1, the hydrophobic layer 2 is in contact with the surface of the substrate 1, and the hydrophilic layer 3 is arranged on one side of the hydrophobic layer 2 opposite to the substrate 1; or the hydrophilic layer 3 is in contact with the surface of the substrate 1, and the hydrophobic layer 2 is arranged on the side, opposite to the substrate 1, of the hydrophilic layer 3.

Preferably, as shown in fig. 1, in the present invention, the water-repellent layer 2 is brought into contact with the surface of the substrate, and the hydrophilic layer 3 is provided on the side of the water-repellent layer 2 opposite to the substrate 1, whereby the corrosion prevention performance can be further improved.

In addition, the self-repairing composite coating 4 in the anticorrosive material provided by the invention combines the characteristic that water cannot permeate the self-repairing composite coating 4 with the advantage of actively repairing a damaged position, and has excellent anticorrosive performance and self-repairing performance. In addition, the self-healing composite coating 4 is excellent in biodegradability and adhesion, and can proliferate cells when implanted into a living body.

Third embodiment

A third embodiment of the present invention provides a method for producing an anticorrosive material, comprising the steps of:

preparing a self-repairing layer material by using a hydrophilic substance A;

preparing a hydrophobic material from a hydrophobic substance;

enabling the self-repairing layer material and the hydrophobic material to alternately form a hydrophilic layer 1 and a hydrophobic layer 2 on the surface of a substrate 1, wherein the hydrophilic layer comprises a self-repairing layer 31;

in the present invention, the hydrophobic layer 2 may be brought into contact with the surface of the substrate 1, and the hydrophilic layer 3 may be formed on the side of the hydrophobic layer 2 opposite to the substrate 1; or the hydrophilic layer 3 is contacted with the surface of the substrate 1, and the hydrophobic layer 2 is formed on the side of the hydrophilic layer 3 opposite to the substrate 1. Preferably, the hydrophobic layer 2 is brought into contact with the surface of the substrate 1. According to the invention, the hydrophobic material is contacted with the substrate 1, so that the corrosion resistance of the self-repairing composite coating 4 can be effectively improved.

Further, the method further comprises:

preparing a transition layer material from hydrophilic substances;

forming a transition layer 32 between the self-repairing layer 31 and the hydrophobic layer 2 using the transition layer material; or forming a transition layer 32 on the side of the self-repairing layer 31 opposite to the hydrophobic layer 2 by using the transition layer material, and preferably forming the transition layer 32 between the self-repairing layer 31 and the hydrophobic layer 2 by using the transition layer material.

In the present invention, the anticorrosive material may be formed by superimposing the self-repairing layer 31 on the surface of the hydrophobic layer 2 opposite to the substrate 1, or superimposing the self-repairing layer 31 and the transition layer 32 on the surface of the hydrophobic layer 2 opposite to the substrate 1. Preferably, in order to exert the self-repairing effect of the self-repairing composite coating 4 of the present invention, the transition layer 32 is formed between the self-repairing layer 31 and the water-repellent layer 2.

Specifically, the method comprises the following steps:

bringing a hydrophobic material into contact with the surface of the substrate 1 to form a hydrophobic layer 2;

taking a transition layer material, and placing the substrate 1 containing the hydrophobic layer 2 in the solution of the hydrophilic substance to form a transition layer 32;

a solution containing a hydrophilic substance A (namely: a self-repairing layer material) is taken, and the substrate 1 containing the transition layer 32 is placed in the solution containing the hydrophilic substance A to form the self-repairing layer 31.

In general, the solution containing the hydrophilic substance a may be an aqueous solution containing the hydrophilic substance a.

Further, the method comprises the steps of:

taking a solution containing a hydrophilic substance a and a solution containing a hydrophilic substance a '(namely: a self-repairing layer material), putting the substrate 1 containing the transition layer 32 into the solution containing the hydrophilic substance a for soaking, taking out the substrate, and then putting the substrate into the solution containing the hydrophilic substance a' for soaking to form a self-repairing layer 31; wherein the hydrophilic substance a reacts with the hydrophilic substance a' to form the hydrophilic substance A containing at least one of the dynamic covalent bonds.

The preparation method of the hydrophobic material comprises the following steps: and (3) dissolving the hydrophobic substance in the first solvent to obtain the hydrophobic material. In the hydrophobic material, the content of the hydrophobic substance is 0.1-10 wt%. Preferably, the hydrophobic material is doped with a corrosion inhibitor, and the concentration of the corrosion inhibitor can be 0.001-0.01 g/mL.

The preparation method of the transition layer material comprises the following steps: and dissolving a hydrophilic substance in a second solvent to obtain the transition layer material, wherein the concentration of the hydrophilic substance is 0.1-10 mg/mL. In the hydrophilic substance-containing solution, the pH value may be adjusted to be alkaline by using a pH adjuster, which may be NaOH or the like.

The preparation method of the self-repairing layer material can comprise the step of dissolving a material containing the hydrophilic substance A in a third solvent to obtain a solution of the hydrophilic substance A, wherein the concentration of the hydrophilic substance A is 1-10 mg/mL.

The preparation method of the self-repairing layer material can also comprise the steps of dissolving a hydrophilic substance a in a third solvent to obtain a solution of the hydrophilic substance a, wherein the concentration of the hydrophilic substance a is 1-10 mg/mL; dissolving a hydrophilic substance a ' in a third solvent to obtain a solution of the hydrophilic substance a ', wherein the concentration of the hydrophilic substance a ' is 1-10 mg/mL.

In the present invention, the hydrophilic substance a may be ethylene glycol chitosan and derivatives thereof, for example: methyl glycol chitosan, trimethyl ammonium glycol chitosan, and the like; the hydrophilic substance a' may be p-aldehyde benzoic acid-polyethylene glycol and derivatives thereof, etc., such as: methoxy-p-aldehyde benzoic acid-polyethylene glycol, p-aldehyde benzoic acid-polyethylene glycol-p-aldehyde benzoic acid.

In the present embodiment, the first solvent is a solvent capable of dissolving the hydrophobic substance, and examples thereof include: dichloromethane, chloroform, benzene, tetrahydrofuran, and the like; the second solvent is a solvent that can dissolve the hydrophilic substance, for example: alcohols, water, etc., and the third solvent may be alcohols, water, etc.

In general, in the present invention, the process of alternating formation may be one or a combination of two or more of tiling, coating, dipping, casting, and spraying.

Further, the method of the present invention further comprises: a step of surface-treating the substrate 1; the self-repairing composite coating 4 can be more firmly adhered to the surface of the substrate 1 by performing surface treatment on the substrate 1.

Preferably, the surface of the substrate 1 is subjected to modification treatment with a modifier; the modifier comprises an acidic solution, preferably, the acidic solution comprises one or a combination of more than two of sulfuric acid, hydrochloric acid, nitric acid and phosphoric acid. In the present embodiment, the modifier may be a mixed solution containing an acidic solution, for example: alcohols (e.g., at least one of ethanol, propanol, butanol, and glycerol), and inorganic salts.

In general, the inorganic salts used may be chosen in accordance with the corrosion protection materials, in order not to introduce other impurities, such as: when Mg metal is used as the substrate 1 and the modification is carried out with nitric acid, Mg (NO) may be selected₃)₂As an inorganic salt component.

Examples

Embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will appreciate that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

Example 1

In the present example, the following copper mesh was used as a substrate.

(1) Cutting the copper mesh into a sample with the length of 3cm and the width of 3cm to obtain a matrix Cu which is recorded as Cu;

(2) preparing 2.5 wt% of dichloromethane solution of polycaprolactone (doped with 0.001g/ml of corrosion inhibitor paeonol) to obtain the hydrophobic material.

(3) 2mg/ml polydopamine in ethanol solution is prepared, and the pH is adjusted to 10 by sodium hydroxide.

(4) Taking glycol chitosan powder to prepare 4mg/ml glycol chitosan aqueous solution.

(5) Taking the p-aldehyde benzoic acid-polyethylene glycol powder to prepare 4mg/ml p-aldehyde benzoic acid-polyethylene glycol aqueous solution.

(6) Soaking the substrate Cu in a hydrophobic material for 45s, and drying to form a hydrophobic layer; the anticorrosive material I provided with only the hydrophobic layer was obtained and is designated Cu-P @ PCL.

(7) Soaking the substrate Cu in an ethanol solution of polydopamine for 12h, and drying to form a transition layer; soaking in water solution of glycol chitosan for 15min, drying, soaking in water solution of p-aldehyde benzoic acid-polyethylene glycol for 15min, and drying to form self-repairing layer; an anticorrosive material II provided with only a hydrophilic layer was obtained and referred to as Cu-PGD.

(8) And bonding the hydrophobic layer of the anti-corrosion material (Cu-P @ PCL) only provided with the hydrophobic layer above the hydrophilic layer of the anti-corrosion material (Cu-PGD) only provided with the hydrophilic layer to obtain the anti-corrosion material III, namely Cu-PGD-P @ PCL.

(9) And (3) bonding the hydrophilic layer of the anti-corrosion material (Cu-PGD) only provided with the hydrophilic layer above the hydrophobic layer of the anti-corrosion material (Cu-P @ PCL) only provided with the hydrophobic layer to obtain the anti-corrosion material IV, which is named as Cu-P @ PCL-PGD.

Example 2

(1) High purity magnesium was cut into sheet-like substrates having dimensions of 10mm x 2mm, followed by grinding of the high purity magnesium sequentially with abrasive paper having a grit of 80/240/1000/3000/5000, and the ground samples were washed with ethanol and deionized water and noted as Mg. The scanning picture of the electron microscope is shown on the left of FIG. 3.

(2) Preparing an aqueous solution of a modifier, wherein HNO is contained in the aqueous solution of the modifier₃Has a concentration of 22g/L, Mg (NO)₃)₂The concentration of (2) is 150g/L, and the concentration of ethanol is 300 g/L. Soaking Mg in a modifier solution for 60s, then cleaning a sample by using distilled water, and finally drying at room temperature to obtain a modified matrix Mg, which is recorded as Mg-H;

(3) 2mg/mL polydopamine in ethanol solution was prepared and adjusted to pH 10 with sodium hydroxide.

(4) Taking glycol chitosan powder to prepare a 4mg/ml glycol chitosan aqueous solution.

(6) Preparing 2.5 wt% of dichloromethane solution of polycaprolactone (doped with 0.001g/ml of corrosion inhibitor paeonol) to obtain the hydrophobic material.

(7) Soaking the modified matrix Mg in an ethanol solution of polydopamine for 12h, and drying to form a transition layer; soaking in water solution of glycol chitosan for 15min, drying, soaking in water solution of p-aldehyde benzoic acid-polyethylene glycol for 15min, and drying to form self-repairing layer; an anticorrosive material V provided with only a hydrophilic layer was obtained and referred to as Mg-PGD.

(8) Soaking an anti-corrosion material (Mg-PGD) only provided with a hydrophilic layer in a hydrophobic material to form a hydrophobic layer; obtaining the anticorrosive material VI which is marked as Mg-PGD-P @ PCL.

Example 3

Step (1) to step (6) of example 3 are the same as those of example 2, and example 3 differs from example 2 only in that: the sequence of the step (7) and the step (8) is interchanged, and the method specifically comprises the following steps:

(7) soaking the modified matrix Mg in a hydrophobic material to form a hydrophobic layer; an anti-corrosion material VII provided with only a hydrophobic layer is obtained, denoted Mg-P @ PCL.

(8) Soaking the anti-corrosion material (Mg-P @ PCL) only provided with the hydrophobic layer in an ethanol solution of polydopamine for 12h, and drying to form a transition layer; soaking in water solution of glycol chitosan for 15min, drying, soaking in water solution of p-aldehyde benzoic acid-polyethylene glycol for 15min, and drying to form self-repairing layer; obtaining the anticorrosive material VIII which is marked as Mg-P @ PCL-PGD, and the scanning electron microscope picture is shown on the right of figure 3.

Performance testing

1. Water Capacity test and contact Angle test of the base Cu and the Corrosion protection materials I-VI of example 1

Taking a substrate Cu, an anti-corrosion material I (Cu-P @ PCL) only provided with a hydrophobic layer, an anti-corrosion material II (Cu-PGD) only provided with a hydrophilic layer, an anti-corrosion material III (Cu-PGD-P @ PCL) and an anti-corrosion material IV (Cu-P @ PCL-PGD) for carrying out water storage capacity test; the method comprises the following specific steps:

taking a substrate Cu, an anti-corrosion material I (Cu-P @ PCL) only provided with a hydrophobic layer, an anti-corrosion material II (Cu-PGD) only provided with a hydrophilic layer, an anti-corrosion material III (Cu-PGD-P @ PCL) and an anti-corrosion material IV (Cu-P @ PCL-PGD) of the invention as samples to be detected, fixing the samples between two syringes by using a clamp, dripping liquid drops from top to bottom, and observing the height of water in the syringes. The specific test results are shown in table 1 below.

Water droplets were dropped on the surfaces of a substrate Cu, an anticorrosive material I (Cu-P @ PCL) provided with only a hydrophobic layer, an anticorrosive material II (Cu-PGD) provided with only a hydrophilic layer, an anticorrosive material III (Cu-PGD-P @ PCL) and an anticorrosive material IV (Cu-P @ PCL-PGD) of the present invention, and the contact angles of water were measured, and the results are shown in table 1 and fig. 4.

TABLE 1

Test items	Height of water storage/cm	Contact Angle/°
			Cu
	0	84.2
			Cu-PGD	0	0
Cu-P@PCL	1.9	115.3
			Cu-PGD-P@PCL	2.6	109.6
Cu-P@PCL-PGD	5.1	65.1

As can be seen from the water storage capacity test results in table 1, the substrate Cu (Cu) and the corrosion-resistant material II (Cu-PGD) provided with only the hydrophilic layer do not have water storage capacity, and water easily permeates therethrough; the anti-corrosion material I (Cu-P @ PCL) only provided with the hydrophobic layer has certain water storage capacity, and water is not easy to permeate; compared with the anticorrosion material I (Cu-P @ PCL) only provided with the hydrophobic layer, the anticorrosion material III (Cu-PGD-P @ PCL) provided by the invention has better water storage capacity, but still has water permeation. Compared with the corrosion-resistant material III (Cu-PGD-P @ PCL), the corrosion-resistant material IV (Cu-P @ PCL-PGD) has better water storage capacity and almost no water penetrates through the corrosion-resistant material IV. It is thus clear that the anticorrosive material of the present invention has excellent permeation preventive properties and further excellent anticorrosive properties.

As can be seen from the contact angle test results of table 1 and fig. 4, the hydrophobic layer is hydrophobic, and the hydrophilic layer is hydrophilic, and both can be coated on the surface of the base copper.

2. Contact Angle measurement of magnesium ingot surface

And respectively dripping water drops on the surfaces of samples to be detected of a matrix Mg (Mg), a modified matrix Mg (Mg-H), an anti-corrosion material V (Mg-PGD), an anti-corrosion material VI (Mg-PGD-P @ PCL), an anti-corrosion material VII (Mg-P @ PCL) and an anti-corrosion material VIII (Mg-P @ PCL-PGD), and measuring the sizes of contact angles of the samples to be detected, wherein the sizes of the contact angles are specifically shown in the following table 2 and fig. 5.

TABLE 2

Test items	Contact Angle/°
		Mg	56.9
Mg-H	53.6
		Mg-P@PCL	104.09
Mg-PGD	28.5
		Mg-PGD-P@PCL	112.49
Mg-P@PCL-PGD	55.9

As can be seen from the contact angle test results of table 2 and fig. 5, the hydrophobic layer is hydrophobic, and the hydrophilic layer is hydrophilic, and both can be coated on the surface of the substrate magnesium.

3. Surface corrosion Performance test

A substrate Mg (Mg), a modified substrate Mg (Mg-H), the anticorrosive material V (Mg-PGD) of example 2, the anticorrosive material VI (Mg-PGD-P @ PCL) and the anticorrosive material VII (Mg-P @ PCL) of example 3 and the anticorrosive material VIII (Mg-P @ PCL-PGD) were taken as samples to be tested, and the samples were immersed in SBF simulated body fluid at 37 +/-0.5 ℃ for 3 days, 8 days, 12 days and 21 days, and then the samples were taken out and the change of the weight loss rate with time was tested, and the results are shown in Table 3.

TABLE 3

Weight loss ratio (%)	Mg	Mg-H	Mg-P@PCL	Mg-PGD	Mg-PGD-P@PCL	Mg-P@PCL-PGD
							3d	7.73	7.55	3.55	6.35	2.73	1.14
8d	9.56	8.48	7.74	7.24	2.8	1.16
							12d	9.92	10.9	7.48	8.64	6.79	1.19
21d	12.97	11.92	10.19	11.55	9.48	5.20

As can be seen from Table 3, the weight loss ratio of Mg at 3d was 7.73%, the weight loss ratio of Mg-PGD-P @ PCL at 3d was only 2.73, and the weight loss ratio at 12d was smaller than the initial value of bare magnesium. The weight loss ratio of Mg-P @ PCL-PGD is only 1.14% at 3d and keeps a small value all the time, and the weight loss ratio of Mg-P @ PCL-PGD at 21d is smaller than the initial value of naked magnesium. The above results show that water spread on the surface of the corrosion-resistant material of the present invention does not permeate, increasing the corrosion resistance of the metal.

4. Self-repair performance test

A scratch is scratched on the changed surfaces of a matrix Mg (Mg) and an anti-corrosion material VIII (Mg-P @ PCL-PGD), and then the matrix Mg (Mg) and the anti-corrosion material VIII (Mg-P @ PCL-PGD) are soaked in SBF simulated body fluid at 37 +/-0.5 ℃ for 0h, 72h, 216h and 468h, and then samples are taken out to observe the self-repairing capability of the matrix, and the results are shown in FIGS. 6-10.

As can be seen from fig. 6, at 0h, all materials were not corroded.

As can be seen from fig. 7, at 72h, the Mg surface of the sample began to be piled up by corrosion products; the anticorrosive material VIII (Mg-P @ PCL-PGD) is relatively complete.

As can be seen from FIG. 8, at 216h, the Mg surface of the sample is almost accumulated by corrosion products, which shows that the sample has no self-repairing capability at all; the anticorrosive material VIII (Mg-P @ PCL-PGD) is still relatively intact.

As can be seen from FIGS. 9 and 10, the scratches on the surface of the anticorrosion material VIII (Mg-P @ PCL-PGD) become smaller from 72h, and no scratches are observed from 468h, which indicates that the coating has self-repairing function and the surface has strong corrosion resistance.

5. Impedance detection

In order to explore the self-repairing capability of the self-repairing composite coating, the invention also tests the change trend of the impedance value of the sample at different time, specifically, the sample is soaked in the SBF simulated body fluid and taken out at different days or hours to test the impedance spectrum of the sample, the larger the radius of the impedance spectrum is, the better the corrosion resistance is, and the result is shown in FIG. 11.

As can be seen from FIG. 11, the resistance value of the bare magnesium gradually increases from 0h to 60h, and decreases after 84h, which indicates that the passivation layer generated by the magnesium corrosion can slow down the corrosion, but when the passivation layer disappears, the corrosion continues to occur.

And when the time is 0H to 36H, the resistance value of Mg-H is increased and then reduced, which indicates that the corrosion continues to occur after the passivation layer disappears.

The resistance value of Mg-PGD is gradually reduced after 0h to 36h, and the resistance value begins to rise after 108h, which indicates that a passivation layer is formed in the corrosion reaction, and the corrosion speed is reduced;

and when the resistance value of Mg-P @ PCL is reduced within 0h-84h, the resistance value is gradually increased within 84-180h, and the resistance value is reduced after 180h, which indicates that the scratch position is corroded, and magnesium ions generated by corrosion and paeonol in the hydrophobic layer material perform a complex reaction to form a new coating to repair the damaged position, so that the corrosion is weakened.

The result of Mg-PGD-P @ PCL is similar to that of Mg-P @ PCL, which shows that the self-repairing of the coating weakens the corrosion of metal.

And (3) the resistance value of Mg-P @ PCL-PGD tends to be stable in 0-180h, which indicates that the scratch has small influence on the coating, and the resistance value is increased to the maximum after 180h, so that the self-repairing is carried out on the coating at the moment, and the corrosion resistance is enhanced.

The above examples of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. Use of a self-healing composite coating for corrosion protection, the self-healing composite coating comprising: hydrophobic and hydrophilic layers in contact, wherein

The hydrophobic layer comprises a hydrophobic substance;

the hydrophilic layer comprises a self-healing layer comprising a hydrophilic species a comprising at least one of dynamic covalent bonds;

the self-repairing composite coating is formed on the surface of a substrate, the hydrophobic layer is in contact with the surface of the substrate, and the hydrophilic layer is arranged on one side of the hydrophobic layer opposite to the substrate; or

The hydrophilic layer is in contact with the surface of the substrate, and the hydrophobic layer is arranged on the side, opposite to the substrate, of the hydrophilic layer;

the hydrophobic layer is doped with a corrosion inhibitor;

the corrosion inhibitor comprises one or more of paeonol, honey, orange peel and bamboo leaves.

2. The use of the self-healing composite coating of claim 1 for corrosion protection, wherein the hydrophilic layer further comprises a transition layer in contact with the self-healing layer; wherein

the transition layer includes a hydrophilic substance.

3. The use of claim 1 or 2 wherein the surface of the self-healing composite coating has an irregular structure.

4. The use of claim 3, wherein the irregular structure comprises at least one of a concave structure, a convex structure, and a mesh structure.

5. The use of claim 1 or 2, wherein the dynamic covalent bond comprises at least one of an amide bond, a disulfide bond, an imine bond, and an acylhydrazone bond.

6. An anti-corrosion material, which is characterized by comprising a substrate and a self-repairing composite coating formed on the surface of the substrate; the self-healing composite coating is as set forth in any one of claims 1-5.

7. The corrosion-resistant material according to claim 6, wherein the substrate is a surface-treated substrate.

8. The anticorrosive material according to claim 7, wherein the surface of the substrate has a network structure after the surface treatment.

9. A method for producing an anti-corrosion material according to any one of claims 6 to 8, characterized by comprising:

preparing a self-repairing layer material by using a hydrophilic substance A;

preparing a hydrophobic material from a hydrophobic substance;

10. The method of producing an anticorrosive material according to claim 9, further comprising preparing a transition layer material from a hydrophilic substance;

11. The production method according to claim 9 or 10, characterized by further comprising: and carrying out surface treatment on the substrate.

12. The production method according to claim 11, characterized in that the surface of the base body is subjected to modification treatment with a modifier; the modifying agent comprises an acidic solution.

13. The method of claim 12, wherein the modifier further comprises an alcohol and/or an inorganic salt.