CN111286222A

CN111286222A - Solid solution anticorrosive pigment with multistage self-assembly magic cube structure

Info

Publication number: CN111286222A
Application number: CN202010079492.3A
Authority: CN
Inventors: 刘金库; 张婧玉; 盛潇潇; 卢怡; 袁晓宇; 周丹; 张敏; 孙慧萍; 郭小娇; 范逸玮
Original assignee: East China University of Science and Technology
Current assignee: East China University of Science and Technology
Priority date: 2020-02-04
Filing date: 2020-02-04
Publication date: 2020-06-16

Abstract

The invention belongs to the technical field of material chemistry, and particularly relates to a preparation method of a solid solution anticorrosive pigment with a multistage self-assembly magic cube structure. The metal-doped zinc oxide solid solution shows a multi-stage self-assembly phenomenon, forms a multi-stage ordered magic cube square structure, and realizes the synergistic effect of factors such as multi-layer shielding, electron transfer delay, electrolyte deflection and the like, so that the anti-corrosion performance is remarkably improved, and a novel high-efficiency anti-corrosion pigment is provided for the field of metal corrosion prevention.

Description

Solid solution anticorrosive pigment with multistage self-assembly magic cube structure

Technical Field

The invention belongs to the technical field of material chemistry, and particularly relates to a preparation method of a solid solution anticorrosive pigment with a multistage self-assembly magic cube structure.

Background

With the development of semiconductor technology and magnetic theory, people have increasingly concentrated interest in spintronics, and open up new fields on the basis of volume reduction and good comprehensive performance. Diluted Magnetic Semiconductors (DMS) exhibit magnetic and semiconductor properties. With the exploitation of electron spin and electron orbital degrees of freedom, semiconductor materials exhibit several physical phenomena such as faraday effect, extraordinary hall effect, and proposed magnetic insulator-metal conversion. Therefore, DMS materials play an important role in the fields of magnetism, electricity and light, especially in the information and automation industries.

Theorists believe that zinc oxide is an ideal host semiconductor material that supports high curie temperature (high TC) ferromagnetic and potential spintronic device applications. Room temperature ferromagnetism of zinc oxide doped with a non-magnetic element or a three-dimensional transition metal has been widely reported. Doped ZnO exhibits magnetism due to magnetic exchange of its sp-d electrons. Early studies reported the stable formation conditions of films and oxygen vacancies of doped ZnO nanocrystals such as Ni-ZnO, Co-ZnO, Cr-ZnO and Mn-ZnO and their magnetic properties. It is noteworthy that zinc oxide materials have good magnetic properties in many practical applications, such as enhancing the antibacterial material, solar cells and photocatalytic fields at the same time. While DMS materials have met with initial good success in corrosion protection, their practical application is unclear. The experimenter confirms that ZnO has corrosion protection capabilities in some cases. Some of the most important properties of the corrosion protection material are hydrophobicity, surface energy, roughness, indentation hardness and degree of crosslinking. However, we have found that a key factor in measuring the lifetime and performance of coatings is the environmental compatibility of the barrier. In this regard, the use of a protective coating with barrier properties to protect against corrosion is beneficial to maintaining the life cycle of the metal. The corrosion inhibitor can further improve the corrosion resistance. When doped zinc oxide is added as a magnetic inhibitor to the anti-corrosion pigment, its anti-corrosion properties will be improved. In addition, the ferromagnetic mechanism of zinc oxide corrosion protection systems remains controversial. The development of a practical, functional ZnO DMS is fundamental to its use in spintronics, but remains a central challenge in this field. When this challenge is addressed, an understanding of the fundamental origin of this interesting magnetic behavior in the field of corrosion protection will be improved. Magnetism and electricity are fundamental natural phenomena, and a connection of thousands of threads exists between the magnetism and the electricity, so that the connection between the electricity and the corrosion resistance exists objectively. Exploring the relationship between magnetic properties and corrosion prevention is of great significance but also a challenge.

The invention has reference significance for the development and design of anticorrosive materials by doping the zinc oxide solid solution anticorrosive pigment with the magnetic metal. Firstly, the magnetic metal doped zinc oxide solid solution shows a multi-stage self-assembly phenomenon, and an ordered magic cube structure is formed. Secondly, the experimental result shows that the corrosion resistance is obviously improved by the synergistic effect of the factors such as multilayer shielding, electron transfer delay, electrolyte deflection and the like. The Cu-ZnO coating has the highest impedance, and after soaking in 3.50 wt% sodium chloride solution for 168 hours, the impedance of the Cu-ZnO coating is improved by 15 times compared with that of undoped ZnO. In particular, a quantitative relationship between magnetic properties and corrosion protection properties is established.

Disclosure of Invention

The invention aims to provide a solid solution anticorrosive pigment with a multistage self-assembly magic cube structure, and provides a novel efficient anticorrosive pigment for the field of metal corrosion prevention.

The solid solution anticorrosive pigment with the multistage self-assembly magic cube structure is a solid solution with a regular ordered three-dimensional self-assembly structure, the overall appearance is similar to a magic cube, the chemical components are a zinc oxide solid solution doped with magnetic metal, and the molar ratio of zinc atoms to magnetic metal atoms is 25: 1, the corrosion resistance of the paint is far better than that of zinc oxide, and the preparation steps are as follows: adding a certain amount of oxalic acid into a mixed solution containing a zinc source and a magnetic metal source, adjusting the pH value of the solution to 3 by using ammonia water, fully stirring, washing a precipitation precursor, drying in an oven, and calcining an intermediate in a muffle furnace to obtain the solid solution anticorrosive pigment with the excellent anticorrosive performance and the multistage self-assembly magic cube structure.

The specific preparation conditions are as follows:

drying a precursor: the drying temperature is 75-100 ℃, and the drying time is 2-8 h;

calcining a precursor: the calcining temperature is 500-800 ℃, and the calcining time is 1-5 h.

In the invention, the zinc source is zinc nitrate, and the magnetic metal source is ferric nitrate, cobalt nitrate, nickel nitrate and cupric nitrate.

The products obtained by the invention all have a multi-stage self-assembly magic cube structure. Undoped zinc oxide is composed of dense spherical particles with a size of 150-190 nm. The iron-doped zinc oxide solid solution anticorrosive pigment shows a multilayer parallelogram structure consisting of small spherical strips, and the cobalt-doped zinc oxide solid solution anticorrosive pigment, the nickel-doped zinc oxide solid solution anticorrosive pigment and the copper-doped zinc oxide solid solution anticorrosive pigment maintain the irregular strips stacked in layers (see the attached figure 1 in the specification). Taking copper doped zinc oxide solid solution anticorrosive pigments as an example, the morphology tends to be a relatively regular cubic structure. The various forms of gaps, channels, pores are formed by diffusion of the evolved gases in the crystal, all of which are generated during the calcination process. The overall size of the iron, cobalt and nickel doping is reduced compared to undoped zinc oxide, while the copper doping results in a further reduction in size, which is beneficial to enhance the viscosity and dispersion stability of the system. More limited in size may be substitution, compensation and interstitial incorporation of cationic copper dopants.

0.8 g of solid solution anticorrosive pigment with a multilevel self-assembly magic cube structure is dispersed in 10 g of epoxy resin (E20) and is subjected to intensive stirring for 3 hours to obtain the anticorrosive paint. Then 2g of curing agent (polyamide) was added to the mixture and reacted for 10 min. The coating is applied to iron with the thickness of 40 multiplied by 10 multiplied by 5 mm, and the steel needs to be ground by a friction method by using silicon carbide paper with the mesh size of 600. The sample was allowed to dry naturally at room temperature for 7 days. The corrosion behavior was investigated by testing Electrochemical Impedance Spectroscopy (EIS) at an IM6e electrochemical workstation (Zahner-electric, Germany). The three-electrode cell is placed in 3.50 wt% sodium chloride solution, an iron block is used as a working electrode, a saturated calomel electrode is used as a reference electrode, and a platinum sheet is used as an auxiliary electrode to work. The frequency ranged from 100 kHz to 100 MHz, and the perturbation of the measurement was 10 mV. To quantitatively analyze the corrosion resistance of the X-ZnO coating, potentiodynamic polarization tests of the coating were carried out at 298k with AUTOLAB G1 in a 3.5 wt% sodium chloride solution at a scan rate of 1 mV/s at-0.30 to-1.20V.

The weak magnetic field around the multi-stage self-assembly magic cube structure solid solution anticorrosive pigment not only influences the structure and performance of the coating, but also influences the electrolyte penetrating to the iron surface. The corrosion products on the zinc oxide coating are in a 'flower shape', which is caused by iron oxide, and the corrosion products on the multi-stage self-assembly magic cube structure solid solution anticorrosive pigment coating are in a 'tree shape'. The main constituents of the corrosion products are not changed, but their distribution is quite different. The reason why the latter coating layer exhibits more durable corrosion prevention is that it is affected by a weak magnetic field when the electrolyte penetrates the iron surface. The electrolyte then deflects along the magnetic field lines, forming dendritic paths. The product forms along the sides of the "leg" rather than spreading completely across the iron surface, thereby retarding further corrosion.

The invention has the advantages that:

1. the hole and gap structures in the three-dimensional cubic multilayer structure of the multi-stage self-assembly magic cube type cubic structure solid solution anticorrosive pigment can intercept a large amount of air, so that the hydrophobicity is increased, and the anticorrosive performance is facilitated.

2. The calcination preparation of the pigment provides high energy, and the particle size and arrangement are difficult to control due to the high energy of the particles. However, in this case, the magnetic metal doped zinc oxide solid solution anticorrosive pigment can also ensure the ordered arrangement, which indicates that certain force exists between molecules, and can maintain a stable self-assembled magic cube structure.

3. The ordered arrangement structure of the magnetic metal doped zinc oxide solid solution anticorrosive pigment inhibits the transfer of water and chloride ions, and plays a certain role in hindering.

4. After the paint prepared by the magnetic metal doped zinc oxide solid solution anti-corrosion pigment is soaked in a 3.50 wt% sodium chloride solution for 168 hours, the impedance of the paint is improved by 15 times compared with that of undoped ZnO, and the paint shows extremely excellent anti-corrosion performance.

Description of the drawings:

FIG. 1 (a) undoped zinc oxide, (b) iron metal doped zinc oxide solid solution anticorrosion pigment, (c) cobalt metal doped zinc oxide solid solution anticorrosion pigment, (d) nickel metal doped zinc oxide solid solution anticorrosion pigment, (e) copper metal doped zinc oxide solid solution anticorrosion pigment

Detailed Description

The present invention will be further illustrated by the following specific examples.

Example 1

Oxalic acid (0.05 mol) was added to 500 mL of the mixed solution containing 14.85 g of zinc nitrate hexahydrate (0.05 mol) and 0.808 g of iron (III) nitrate nonahydrate (0.002 mol). Then, the pH of the solution was adjusted to 3 with ammonia. After stirring well for 2 h, the precipitated precursor was washed and dried in an oven at 75 ℃ for 8 h. And then calcining the intermediate in a muffle furnace at 800 ℃ for 1 h to obtain the iron metal doped zinc oxide solid solution anticorrosive pigment with excellent anticorrosive performance.

Example 2

Oxalic acid (0.05 mol) was added to 500 mL of the mixed solution containing 14.85 g of zinc nitrate hexahydrate (0.05 mol) and 0.582g of cobalt nitrate hexahydrate (0.002 mol). Then, the pH of the solution was adjusted to 3 with ammonia. After stirring well for 2 h, the precipitated precursor was washed and dried in an oven at 100 ℃ for 2 h. And then calcining the intermediate in a muffle furnace at 500 ℃ for 2 h to obtain the cobalt metal doped zinc oxide solid solution anticorrosive pigment with excellent anticorrosive performance.

Example 3

Oxalic acid (0.05 mol) was added to 600 mL of a mixed solution containing 14.85 g of zinc nitrate hexahydrate (0.05 mol) and 0.359 g of copper (II) nitrate trihydrate (0.002 mol). Then, the pH of the solution was adjusted to 3 with ammonia. After stirring well for 2 h, the precipitated precursor was washed and dried in an oven at 80 ℃ for 2 h. And then calcining the intermediate in a muffle furnace at 500 ℃ for 4 h to obtain the copper metal doped zinc oxide solid solution anticorrosive pigment product with excellent anticorrosive performance.

Example 4

Oxalic acid (0.05 mol) was added to 500 mL of the mixed solution containing 14.85 g of zinc nitrate hexahydrate (0.05 mol) and 0.582g of nickel nitrate hexahydrate (0.002 mol). Then, the pH of the solution was adjusted to 3 with ammonia. After stirring well for 2 h, the precipitated precursor was washed and dried in an oven at 80 ℃ for 2 h. And then calcining the intermediate in a muffle furnace at 500 ℃ for 2 h to obtain a nickel metal doped zinc oxide solid solution anticorrosive pigment product with excellent anticorrosive performance.

Claims

1. The solid solution anticorrosive pigment with the multistage self-assembly magic cube structure is a solid solution with a regular ordered three-dimensional self-assembly structure, the overall appearance is similar to a magic cube, the chemical components are a zinc oxide solid solution doped with magnetic metal, and the molar ratio of zinc atoms to magnetic metal atoms is 25: 1, the corrosion resistance of the paint is far better than that of zinc oxide, and the preparation steps are as follows: adding a certain amount of oxalic acid into a mixed solution containing a zinc source and a magnetic metal source, adjusting the pH value of the solution to 3 by using ammonia water, fully stirring, washing and drying a precipitate precursor in an oven, and calcining an intermediate in a muffle furnace to obtain the multi-stage self-assembly magic cube type cubic structure solid solution anticorrosive pigment with excellent anticorrosive performance, wherein the drying temperature is 75-100 ℃, the drying time is 2-8 hours, the calcination temperature of the precursor is 500-800 ℃, the calcination time is 1-5 hours, the zinc source is zinc nitrate, and the magnetic metal source is ferric nitrate, cobalt nitrate, nickel nitrate or copper nitrate.