阅读说明：本技术 一种用于金属表面的生物涂料及其制备方法和应用 (Biological coating for metal surface and preparation method and application thereof ) 是由 杨黎晖 王盈 徐玮辰 蒋全通 王秀通 李言涛 黄彦良 于 2021-05-25 设计创作，主要内容包括：本发明提出了一种用于金属表面的生物涂料及其制备方法和应用。本发明的生物涂料包括缓冲溶液、植酸溶液和贻贝粘蛋白原液；缓冲溶液的摩尔浓度为0.08-0.10mol/L,缓冲溶液的体积为60-110份；植酸溶液的摩尔浓度为6-12mmol/L,植酸溶液的体积为5-6份；贻贝粘蛋白原液在生物涂料中的质量浓度为0.42-0.63mg/mL。本发明还给出了上述生物涂料的制备方法及其在金属表面的应用。本发明是一种生物涂料,贻贝粘蛋白原液、植酸溶液和缓冲溶液相互作用,相互促进,在金属表面固化并形成生物涂层,这种生物涂层不含有毒性物质,绿色环保,使用方便,防腐性能好,提高了金属在带水环境下的使用寿命。(The invention provides a biological coating for a metal surface and a preparation method and application thereof. The biological coating comprises a buffer solution, a phytic acid solution and a mussel mucin stock solution; the molar concentration of the buffer solution is 0.08-0.10mol/L, and the volume of the buffer solution is 60-110 parts; the molar concentration of the phytic acid solution is 6-12mmol/L, and the volume of the phytic acid solution is 5-6 parts; the mass concentration of the mussel mucin stock solution in the biological paint is 0.42-0.63 mg/mL. The invention also provides a preparation method of the biological coating and application of the biological coating on a metal surface. The invention is a biological coating, mussel adhesive protein stock solution, phytic acid solution and buffer solution interact with each other to promote each other, and the biological coating is solidified on the surface of metal and formed.)

1. A biological coating for metal surfaces, which is characterized by comprising the following raw materials:

the molar concentration of the buffer solution is 0.08-0.10mol/L, and the volume of the buffer solution is 60-110 parts;

the phytic acid solution has the molar concentration of 6-12mmol/L and the volume of 5-6 parts;

the mass concentration of the mussel adhesive protein stock solution in the biological paint is 0.42-0.63 mg/mL.

2. The biological coating for metal surfaces according to claim 1, characterized in that:

the purity of the mussel adhesive protein stock solution is not lower than 95%, the mussel adhesive protein stock solution is stored in an acetic acid-sodium acetate buffer solution, and the mass concentration of the mussel adhesive protein stock solution in the acetic acid-sodium acetate buffer solution is 4.5-5.5 mg/mL.

3. The biological coating for metal surfaces according to claim 2, characterized in that:

the using amount of the mussel mucin stock solution stored in the acetic acid-sodium acetate buffer solution is 10-15 parts by volume.

4. The biological coating for metal surfaces according to claim 1, characterized in that:

the pH value of the biological coating is 7.8-8.3.

5. The biological coating for metal surfaces according to claim 1, characterized in that:

the pH value of the buffer solution is 8.0-8.3.

6. The biological paint for metal surfaces according to claim 5, characterized in that:

the buffer solution is sodium bicarbonate solution or potassium bicarbonate solution.

7. The method of any one of claims 1 to 6, comprising the steps of:

1) taking a buffer solution and a phytic acid solution, adding the phytic acid solution into the buffer solution, stirring and uniformly mixing to obtain a mixed solution;

2) adding the mussel mucin stock solution into the mixed solution obtained in the step 1), stirring and uniformly mixing to obtain the biological coating.

8. Use of a biological coating for metal surfaces according to any of claims 1 to 6, characterised in that it comprises the following steps:

taking metal, pretreating, depositing in biological paint, wherein the temperature of the biological paint is 30-35 ℃, the deposition time is 12-24h, and drying at 40-50 ℃ for 1-3h to form a biological coating on the metal surface.

9. Use of a biological coating for metal surfaces according to claim 8, characterized in that:

the pretreatment comprises polishing, oil removal, cleaning and air drying, wherein the oil removal treatment is to remove oil by using acetone, and the cleaning treatment is to adopt absolute ethyl alcohol ultrasonic cleaning and deionized water washing.

10. Use of a biological coating for metal surfaces according to claim 8, characterized in that:

the metal is any one of copper, copper alloy, magnesium and magnesium alloy.

Technical Field

The invention relates to the technical field of coatings, in particular to a biological coating for a metal surface and a preparation method and application thereof.

Background

The metal materials such as copper alloy, magnesium alloy and the like are visible everywhere in daily life and work of people, and people have stepped into the era of using the metal materials all the time. However, the metal material is inevitably corroded under the action of the surrounding environment, which not only wastes resources and causes environmental pollution, but also may cause major accidents, and brings great economic loss and social harm to human production and life.

In order to protect metal materials from corrosion, the conventional protection methods mainly include corrosion inhibitor treatment, coating of antirust paint or coating, surface passivation treatment or cathodic protection technology, and the like. The corrosion inhibitor, the antirust paint and the coating are usually related to organic chemical raw materials, or a large amount of organic solvents are used in the construction process, so the use of the corrosion inhibitor, the antirust paint and the coating can cause environmental pollution, and the toxic action is large. In addition, the conventional coating applied on the surface of the metal material is also easy to induce crevice corrosion. In addition, the traditional surface passivation treatment needs to use strong acid or chromic acid and other substances with high toxicity and pollution, which is a potential hazard to the environment and human health. The one-time investment cost of the cathodic protection technology is high, and the technology can be used only under certain conditions; such cathodic protection techniques generally include a sacrificial anode method and an external power supply method, the current output of which cannot be controlled; the sacrificial anode process is difficult and expensive to replace with spent anodes and may be ineffective in high resistivity soil environments.

Disclosure of Invention

The invention aims to provide a biological coating for a metal surface, and a preparation method and application thereof, and aims to solve the problems that the metal surface anticorrosion method in the prior art is high in toxicity, pollutes the environment, is not beneficial to human health, is high in cost, and is inconvenient to use due to the limitation of use conditions.

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

in one aspect, the invention is a bio-paint for metal surfaces, comprising a buffer solution, a phytic acid solution and a mussel mucin stock solution; the molar concentration of the buffer solution is 0.08-0.10mol/L, and the volume of the buffer solution is 60-110 parts; the molar concentration of the phytic acid solution is 6-12mmol/L, and the volume of the phytic acid solution is 5-6 parts; the mass concentration of the mussel mucin stock solution in the biological paint is 0.42-0.63 mg/mL.

The biological coating comprises a buffer solution, a phytic acid solution and a mussel mucin stock solution, wherein the mussel mucin stock solution has excellent water resistance and adhesion performance, the phytic acid can be combined with copper ions and magnesium ions under the chelation effect, and the phytic acid is matched with the buffer solution to provide an alkaline environment with a proper pH value for the solidification of the mussel mucin; the oxygen atom in the phytic acid molecule has strong coordination capacity and is chelated with metal ions on the surfaces of copper, copper alloy, magnesium and magnesium alloy to form a protective phytic acid film layer; the dopa group in the mussel mucin is also chelated with metal ions on the metal surface to form a protective mussel mucin film layer; the phytic acid with low concentration and the mussel mucin have complementary action, and a biological coating is formed on the surfaces of copper and copper alloy, magnesium and magnesium alloy; the six-membered ring of the phytic acid molecule has certain rigidity and has larger steric hindrance, which influences the tight arrangement of the phytic acid molecules, so that a film layer formed by the phytic acid has certain cracks; however, the mussel mucin membrane layer is cross-linked to form a net membrane structure during the sedimentation process, and the phytic acid membrane layer and the mussel mucin membrane layer play a complementary role during the formation of the biological coating. In addition, the mussel mucin film layer has good binding force in a water environment, and is non-toxic, harmless and degradable. The biological coating is solidified on the metal surface and forms a biological coating, the biological coating does not contain substances with toxicity and large pollution, is green and environment-friendly, is convenient to use, is adsorbed on the metal surface, has good corrosion resistance, has good protection effect on the metal surface, prolongs the service life of the metal under a water environment, and is particularly suitable for being widely applied to wading instruments and equipment; in addition, to some metal surfaces that aesthetic property required height, when not needing this coating, only wipe through using mass concentration to be 5% hydrogen peroxide solution, can easily get rid of the coating, do not harm the metal surface, moreover, mussel mucin is a degradable biomaterial, and the coating after getting rid of can not cause environmental pollution, and is safe relieved.

In a preferred embodiment, the purity of the mussel mucin stock solution is not lower than 95%, the mussel mucin stock solution is preserved in acetic acid-sodium acetate buffer solution, and the mass concentration of the mussel mucin stock solution in the acetic acid-sodium acetate buffer solution is 4.5-5.5 mg/mL. The higher the purity of the mussel adhesive protein stock solution is, the better the water resistance is, and the easier the mussel adhesive protein stock solution is to adhere to the metal surface; in order to facilitate the preservation of the mussel mucin stock solution, the mussel mucin stock solution is usually preserved in an acetic acid-sodium acetate buffer solution, the pH value of the acetic acid-sodium acetate buffer solution is generally 4.0-5.0, the mussel mucin stock solution is an acidic buffer solution, the mussel mucin stock solution is stably preserved in the acidic buffer solution, and meanwhile, the performance of the biological coating is not influenced by the use of the acidic buffer solution.

As a preferred embodiment, the mussel mucin stock solution stored in acetic acid-sodium acetate buffer solution is used in an amount of 10 to 15 parts by volume. The invention can also control the concentration of the mussel adhesive protein stock solution in the biological paint by controlling the volume parts of the mussel adhesive protein stock solution stored in the acetic acid-sodium acetate buffer solution, so that the mussel adhesive protein stock solution is convenient to control and easy to master.

As a preferred embodiment, the pH of the biological paint is 7.8 to 8.3. In the invention, mussel mucin stock solution and phytic acid are fully dissolved in alkaline buffer solution, mussel mucin is solidified to form a film layer in an alkaline environment and is crosslinked with the film layer formed by the phytic acid, thus obtaining the alkaline biological coating.

As a preferred embodiment, the pH of the buffer solution is from 8.0 to 8.3. Because the mussel mucin stock solution is usually stored in an acidic buffer solution, the buffer solution adopted by the invention is an alkaline buffer solution, and the environment of the mussel mucin stock solution is adjusted from acidity to alkalinity through the alkaline buffer solution.

As a preferred embodiment, the buffer solution is a sodium bicarbonate solution or a potassium bicarbonate solution. The buffer solution of the invention is usually a weak alkaline buffer solution such as sodium bicarbonate solution or potassium bicarbonate solution, which is beneficial to the combination and solidification of mussel mucin and metal ions, thereby forming the mussel mucin film layer, and the sodium bicarbonate solution is cheap and easy to obtain and has no pollution.

In another aspect, the invention provides a method for preparing a biological coating for a metal surface, comprising the following steps: 1) taking a buffer solution and a phytic acid solution, adding the phytic acid solution into the buffer solution, stirring and uniformly mixing to obtain a mixed solution; 2) adding the mussel mucin stock solution into the mixed solution obtained in the step 1), stirring and uniformly mixing to obtain the biological coating.

The buffer solution of the invention can be ready-made or prepared in situ; and adding the buffer salt into deionized water, fully stirring and dissolving to obtain a buffer solution. The phytic acid solution can be ready-made, and can also be prepared in situ; adding the phytic acid ointment into deionized water, fully stirring and dissolving to obtain the phytic acid solution. The mussel mucin stock solution used in the invention can be a product sold in the market, and can also be extracted from natural mussels according to the existing method. According to the method, the phytic acid solution and the buffer solution are mixed, and then the mussel adhesive protein stock solution is added, so that the mussel adhesive protein stock solution can directly interact with the phytic acid solution under the action of the buffer solution, and the interaction of the mussel adhesive protein stock solution and the phytic acid solution is promoted; the preparation method of the biological coating is simple, convenient to operate and good in stability.

In yet another aspect, the present invention is directed to the use of a biological coating for a metal surface, comprising the steps of: taking metal, pretreating, depositing in a coating solution, wherein the temperature of the coating solution is 30-35 ℃, the deposition time is 12-24h, and drying at 40-50 ℃ for 1-3h to form a biological coating on the metal surface.

When the biological coating is used for performing anti-corrosion treatment on the metal surface, the application method is simple, the metal material is directly deposited in the biological coating, and a biological coating can be formed on the metal surface without other professional auxiliary equipment, so that the biological coating is convenient to use, low in temperature and low in energy consumption. The biological coating formed by the coating has good corrosion resistance, improves the service life of metal in a water environment, and is particularly suitable for being widely applied to wading instruments and equipment; in addition, for some metal surfaces with high aesthetic requirements, when the coating is not needed, the coating can be easily removed by only using 5% hydrogen peroxide for wiping, and the metal surface is not damaged.

As a preferred embodiment, the pretreatment comprises grinding, oil removal, cleaning and air drying, wherein the oil removal treatment is to remove oil by using acetone, and the cleaning treatment is to adopt absolute ethyl alcohol ultrasonic cleaning and deionized water washing. In general, polishing and flattening a processed metal test piece, then removing oil by using acetone, ultrasonically cleaning by using absolute ethyl alcohol, finally washing by using deionized water, and air-drying; the pretreated metal has good surface performance, and the biological coating is convenient to adsorb on the surface.

In a preferred embodiment, the metal is any one of copper, copper alloy, magnesium and magnesium alloy. The metal of the invention can be alloy or pure metal, in particular metal used in wading instruments and equipment.

Compared with the prior art, the invention has the beneficial effects that: the biological coating consists of a buffer solution, a phytic acid solution and a mussel adhesive protein stock solution, the buffer solution, the phytic acid solution and the mussel adhesive protein stock solution are interacted and mutually promoted, and the preparation method is simple, convenient to operate and good in stability; the biological coating is solidified on the metal surface and forms a biological coating, the application method is simple, the metal material is directly deposited in the biological coating, the biological coating can be formed on the metal surface, other professional auxiliary equipment is not needed, the use is convenient, and the energy consumption is low; the biological coating does not contain substances with toxicity and large pollution, is green and environment-friendly, is strongly adsorbed on the metal surface, has good corrosion resistance, has good protection effect on the metal surface, prolongs the service life of the metal under the water environment, and is particularly suitable for being widely applied to wading instruments and equipment; in addition, to some metal surfaces that aesthetic property required height, when not needing this coating, only wipe through using mass concentration to be 5% hydrogen peroxide solution, can easily get rid of the coating, do not harm the metal surface, moreover, mussel mucin is a degradable biomaterial, and the coating after getting rid of can not cause environmental pollution, and is safe relieved.

Drawings

FIG. 1 is a scanning electron microscope image of a brass test piece with a coating obtained in accordance with one embodiment of the present invention;

FIG. 2 is a scanning electron microscope image of a brass coupon without a coating of the present invention deposited thereon;

FIG. 3 is a photograph of a brass coupon having a coating layer obtained in accordance with an embodiment of the present invention after etching;

FIG. 4 is a photographic image of a brass coupon without a coating of the present invention deposited thereon, after etching;

FIG. 5 is a photograph of a cross-cut experimental coating of a brass coupon having a coating obtained in accordance with an embodiment of the present invention;

FIG. 6 is a scanning electron microscope image of a brass test piece with a coating obtained in the first embodiment of the present invention after being wiped with hydrogen peroxide solution with a mass concentration of 5%;

FIG. 7 is a scanning electron microscope photograph of a brass test piece with a coating obtained in example two of the present invention;

FIG. 8 is a scanning electron microscope photograph of a brass test piece with a coating obtained in example III of the present invention.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to specific embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In one aspect, the invention is a bio-paint for metal surfaces, comprising a buffer solution, a phytic acid solution and a mussel mucin stock solution; the molar concentration of the buffer solution is 0.08-0.10mol/L, and the volume of the buffer solution is 60-110 parts; the molar concentration of the phytic acid solution is 6-12mmol/L, and the volume of the phytic acid solution is 5-6 parts; the mass concentration of the mussel mucin stock solution in the biological paint is 0.42-0.63 mg/mL.

Preferably, the purity of the mussel mucin stock solution is not lower than 95%, the mussel mucin stock solution is stored in an acetic acid-sodium acetate buffer solution, and the mass concentration of the mussel mucin stock solution in the acetic acid-sodium acetate buffer solution is 4.5-5.5 mg/mL.

Further, the mussel mucin stock solution stored in the acetic acid-sodium acetate buffer solution is used in an amount of 10-15 parts by volume.

Preferably, the pH of the biological paint is 7.8-8.3.

Preferably, the pH value of the buffer solution is 8.0-8.3.

Further, the buffer solution is sodium bicarbonate solution or potassium bicarbonate solution.

The invention relates to a preparation method of a biological coating for a metal surface, which comprises the following steps:

1) taking a buffer solution and a phytic acid solution, adding the phytic acid solution into the buffer solution, stirring and uniformly mixing to obtain a mixed solution;

2) adding the mussel mucin stock solution into the mixed solution obtained in the step 1), stirring and uniformly mixing to obtain the biological coating.

The invention relates to application of a biological coating for a metal surface, which comprises the following steps: taking metal, pretreating, depositing in a coating solution, wherein the temperature of the coating solution is 30-35 ℃, the deposition time is 12-24h, and drying at 40-50 ℃ for 1-3h to form a biological coating on the metal surface.

Preferably, the pretreatment comprises polishing, oil removal, cleaning and air drying, wherein the oil removal treatment is to remove oil by using acetone, and the cleaning treatment is to adopt absolute ethyl alcohol ultrasonic cleaning and deionized water washing.

Preferably, the metal is any one of copper, copper alloy, magnesium and magnesium alloy.

Example one

The invention relates to a preparation method of a biological coating for a metal surface, which comprises the following steps:

1) adding deionized water into sodium bicarbonate to prepare sodium bicarbonate buffer solution with the molar concentration of 0.10 mol/L;

2) adding phytic acid into deionized water to prepare a phytic acid solution with the concentration of 6 mmol/L;

3) taking 65mL of the sodium bicarbonate buffer solution obtained in the step 1) and 5mL of the phytic acid solution obtained in the step 2), adding the phytic acid solution into the sodium bicarbonate buffer solution, fully stirring, and uniformly mixing to obtain a sodium bicarbonate-phytic acid mixed solution;

4) and (3) adding 10mL of mussel adhesive protein stock solution stored in acetic acid-sodium acetate buffer solution with the pH value of 4.5, wherein the mass concentration of the mussel adhesive protein stock solution is 5.0mg/mL, into the sodium bicarbonate-phytic acid mixed solution obtained in the step 2), fully stirring, and uniformly mixing to obtain the biological coating.

The mussel mucin stock solution in the embodiment is purchased from river-yin Berkson Biochemical technology, Inc., and of course, the mussel mucin stock solution can also be other products; the biological coating obtained in this example was measured to have a pH of 8.1.

The biological paint obtained in the embodiment is applied to the surface of brass for effect verification. Taking a brass sample, polishing and flattening, removing oil by using acetone, ultrasonically cleaning by using absolute ethyl alcohol, fully washing by using deionized water, drying by using cold air, immersing into a biological coating for deposition, wherein the temperature of the biological coating is controlled to be 30 ℃ by using a water bath, and depositing for 12 hours; after the deposition was completed, the brass coupon was dried in an oven at 40 ℃ for 2h to obtain a brass coupon having a mussel mucin-phytic acid-sodium bicarbonate coating on the surface.

The brass test pieces having the mussel mucin-phytic acid-sodium bicarbonate coating layer on the surface and the brass matrix having no mussel mucin-phytic acid-sodium bicarbonate coating layer deposited obtained in this example were observed by placing them on a scanning electron microscope of model Regulus8100 manufactured by Hitachi corporation. As can be seen from the attached figure 1, the mussel mucin-phytic acid-sodium bicarbonate coating is of a compact net structure, is uniformly distributed on the surface of the brass matrix, and has good coating performance on the brass matrix. As can be seen from fig. 2, the surface of the brass substrate on which no mussel mucin-phytic acid-sodium bicarbonate coating is deposited is smooth.

The brass test pieces with the mussel mucin-phytic acid-sodium bicarbonate coating on the surface obtained in the example and the brass matrix without the mussel mucin-phytic acid-sodium bicarbonate coating deposited were subjected to a corrosion performance control experiment. And (3) simultaneously placing the brass test piece with the mussel mucin-phytic acid-sodium bicarbonate coating on the surface and the brass matrix without the mussel mucin-phytic acid-sodium bicarbonate coating in a NaCl solution with the mass concentration of 3.5% for soaking for 24 hours, taking out, and observing the surfaces of the brass test piece and the brass matrix taken out. As can be seen from fig. 3 and fig. 4, the surface of the brass test piece with the mussel mucin-phytic acid-sodium bicarbonate coating is still smooth after being soaked in a 3.5% by mass NaCl solution for 24 hours; however, after the brass matrix without the mussel mucin-phytic acid-sodium bicarbonate coating is soaked in a 3.5% NaCl solution for 24 hours, the surface is rusted, which shows that the mussel mucin-sodium bicarbonate-phytic acid coating has a protective effect on the brass matrix.

The brass test piece with the mussel mucin-phytic acid-sodium bicarbonate coating on the surface obtained in the embodiment is subjected to a coating cross-hatch test according to the national standard GB/T9286-1998 cross-hatch test for paint films of colored paint and varnish, and as can be seen from the attached drawing 5, the coating falling area of the mussel mucin-phytic acid-sodium bicarbonate coating obtained in the invention after the cross-hatch test is less than 5%, and the result is classified into 1 grade, which shows that the mussel mucin-phytic acid-sodium bicarbonate coating obtained in the invention has good adhesion performance on the brass surface.

The brass test piece with the mussel mucin-phytic acid-sodium bicarbonate coating on the surface obtained in the example is wiped by hydrogen peroxide with the mass concentration of 5%, as can be seen from the attached figure 6, the mussel mucin-phytic acid-sodium bicarbonate coating on the surface of the brass test piece is completely removed, the metal surface is not damaged, and the brass test piece after wiping is not different from that before the coating is deposited.

Example two

The invention relates to a preparation method of a biological coating for a metal surface, which comprises the following steps:

1) adding deionized water into sodium bicarbonate to prepare a sodium bicarbonate buffer solution of a sodium bicarbonate buffer solution with a molar concentration of 0.08 mol/L;

2) adding phytic acid into deionized water to prepare a phytic acid solution with the concentration of 8 mmol/L;

3) taking 85mL of the sodium bicarbonate buffer solution obtained in the step 1) and 5mL of the phytic acid solution obtained in the step 2), adding the phytic acid solution into the sodium bicarbonate buffer solution, fully stirring, and uniformly mixing to obtain a sodium bicarbonate-phytic acid mixed solution;

4) and (3) adding 10mL of mussel adhesive protein stock solution stored in acetic acid-sodium acetate buffer solution with the pH value of 4.5, wherein the mass concentration of the mussel adhesive protein stock solution is 5.0mg/mL, into the sodium bicarbonate-phytic acid mixed solution obtained in the step 2), fully stirring, and uniformly mixing to obtain the biological coating.

The mussel mucin stock solution in the embodiment is purchased from river-yin Berkson Biochemical technology, Inc., and of course, the mussel mucin stock solution can also be other products; the biological coating obtained in this example was measured to have a pH of 8.2.

The biological paint obtained in the embodiment is applied to the surface of brass for effect verification. Taking a brass sample, polishing and flattening, removing oil by using acetone, ultrasonically cleaning by using absolute ethyl alcohol, fully washing by using deionized water, drying by using cold air, immersing into a biological coating for deposition, wherein the temperature of the biological coating is controlled to be 35 ℃ by using a water bath, and depositing for 16 hours; after the deposition was completed, the brass coupon was dried in an oven at 50 ℃ for 1h to obtain a brass coupon having a mussel mucin-phytic acid-sodium bicarbonate coating on the surface.

The brass test piece with the mussel mucin-phytic acid-sodium bicarbonate coating on the surface obtained in the example is placed on a scanning electron microscope of Regulus8100 model manufactured by Hitachi company for observation, and as can be seen from the attached figure 7, the mussel mucin-phytic acid-sodium bicarbonate coating is a dense net-shaped structure and is uniformly distributed on the surface of the brass matrix, and the coating performance of the brass matrix is good.

The brass test pieces having a mussel mucin-phytic acid-sodium bicarbonate coating on the surface obtained in this example were subjected to a corrosion performance test experiment in the same manner as in example one. Test results show that after the brass test piece with the mussel mucin-phytic acid-sodium bicarbonate coating on the surface is soaked in a NaCl solution with the mass concentration of 3.5% for 24 hours, the surface is still smooth and free of corrosion.

The coating cross-hatch test is carried out on the brass test piece with the mussel mucin-phytic acid-sodium bicarbonate coating on the surface, which is obtained in the embodiment, according to the method in the embodiment, the test result shows that the coating falling area is less than 5% after the cross-hatch test of the mussel mucin-phytic acid-sodium bicarbonate coating, and the result is graded to be grade 1, which shows that the mussel mucin-phytic acid-sodium bicarbonate coating obtained in the invention has good adhesion performance on the brass surface.

The brass test piece with the mussel mucin-phytic acid-sodium bicarbonate coating on the surface obtained in the example is wiped by hydrogen peroxide with the mass concentration of 5%, and the test result shows that the mussel mucin-phytic acid-sodium bicarbonate coating on the surface of the brass test piece is completely removed, the metal surface is not damaged, and the brass test piece after wiping is not different from the brass test piece before the coating is deposited.

EXAMPLE III

The invention relates to a preparation method of a biological coating for a metal surface, which comprises the following steps:

1) adding deionized water into sodium bicarbonate to prepare a sodium bicarbonate buffer solution of a sodium bicarbonate buffer solution with a molar concentration of 0.10 mol/L;

2) adding phytic acid into deionized water to prepare a phytic acid solution with the concentration of 12 mmol/L;

3) taking 105mL of the sodium bicarbonate buffer solution obtained in the step 1) and 5mL of the phytic acid solution obtained in the step 2), adding the phytic acid solution into the sodium bicarbonate buffer solution, fully stirring, and uniformly mixing to obtain a sodium bicarbonate-phytic acid mixed solution;

4) adding 15mL of mussel adhesive protein stock solution stored in acetic acid-sodium acetate buffer solution with the pH value of 4.5, wherein the mass concentration of the mussel adhesive protein stock solution is 5.0mg/mL, into the sodium bicarbonate-phytic acid mixed solution obtained in the step 2), fully stirring, and uniformly mixing to obtain the biological coating.

The mussel mucin stock solution in the embodiment is purchased from river-yin Berkson Biochemical technology, Inc., and of course, the mussel mucin stock solution can also be other products; the biological coating obtained in this example was measured to have a pH of 8.2.

The biological paint obtained in the embodiment is applied to the surface of brass for effect verification. Taking a brass sample, polishing and flattening, removing oil by using acetone, ultrasonically cleaning by using absolute ethyl alcohol, fully washing by using deionized water, drying by using cold air, immersing into a biological coating for deposition, wherein the temperature of the biological coating is controlled to be 35 ℃ by using a water bath, and depositing for 24 hours; after the deposition was completed, the brass coupon was dried in an oven at 40 ℃ for 3 hours to obtain a brass coupon having a mussel mucin-phytic acid coating on the surface.

The brass test piece with the mussel mucin-phytic acid-sodium bicarbonate coating on the surface obtained in the example is placed on a scanning electron microscope of Regulus8100 model manufactured by Hitachi company for observation, and as can be seen from the attached figure 8, the mussel mucin-phytic acid-sodium bicarbonate coating is a dense net-shaped structure and is uniformly distributed on the surface of the brass matrix, and the coating performance of the brass matrix is good.

The brass test pieces having a mussel mucin-phytic acid-sodium bicarbonate coating on the surface obtained in this example were subjected to a corrosion performance test experiment in the same manner as in example one. Test results show that after the brass test piece with the mussel mucin-phytic acid-sodium bicarbonate coating on the surface is soaked in a NaCl solution with the mass concentration of 3.5% for 24 hours, the surface is still smooth and free of corrosion.

The coating cross-hatch test is carried out on the brass test piece with the mussel mucin-phytic acid-sodium bicarbonate coating on the surface, which is obtained in the embodiment, according to the method in the embodiment, the test result shows that the coating falling area is less than 5% after the cross-hatch test of the mussel mucin-phytic acid-sodium bicarbonate coating, and the result is graded to be grade 1, which shows that the mussel mucin-phytic acid-sodium bicarbonate coating obtained in the invention has good adhesion performance on the brass surface.

The brass test piece with the mussel mucin-phytic acid-sodium bicarbonate coating on the surface obtained in the example is wiped by hydrogen peroxide with the mass concentration of 5%, and the test result shows that the mussel mucin-phytic acid-sodium bicarbonate coating on the surface of the brass test piece is completely removed, the metal surface is not damaged, and the brass test piece after wiping is not different from the brass test piece before the coating is deposited.

Compared with the prior art, the invention has the beneficial effects that: the biological coating consists of a buffer solution, a phytic acid solution and a mussel adhesive protein stock solution, the buffer solution, the phytic acid solution and the mussel adhesive protein stock solution are interacted and mutually promoted, and the preparation method is simple, convenient to operate and good in stability; the biological coating is solidified on the metal surface and forms a biological coating, the application method is simple, the metal material is directly deposited in the biological coating, the biological coating can be formed on the metal surface, other professional auxiliary equipment is not needed, the use is convenient, and the energy consumption is low; the biological coating does not contain substances with toxicity and large pollution, is green and environment-friendly, is strongly adsorbed on the metal surface, has good corrosion resistance, has good protection effect on the metal surface, prolongs the service life of the metal under the water environment, and is particularly suitable for being widely applied to wading instruments and equipment; in addition, to some metal surfaces that aesthetic property required height, when not needing this coating, only wipe through using mass concentration to be 5% hydrogen peroxide solution, can easily get rid of the coating, do not harm the metal surface, moreover, mussel mucin is a degradable biomaterial, and the coating after getting rid of can not cause environmental pollution, and is safe relieved.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.