CN102409379A - Method for preparing super-hydrophobic surface of magnesium alloy matrix by using primary battery method - Google Patents

Abstract

The invention discloses a super-hydrophobic surface of a magnesium alloy substrate prepared by a galvanic battery method, which is characterized in that the oxide layer on the surface of the magnesium alloy plate and other metal plates is removed first, and then the magnesium alloy plate and other metal plates are sequentially used absolute ethanol and Ultrasonic cleaning with deionized water and drying; place the magnesium alloy plate and other metal plates in parallel and symmetrically, and connect them through wires, and then put them into a container filled with electrolyte to form a magnesium alloy-other metal primary battery, After soaking, the magnesium alloy plate is rinsed with deionized water and dried to obtain a binary micro-nano rough structure on the surface of the magnesium alloy plate; finally, the above-mentioned magnesium alloy plate is modified with a low surface energy material to obtain a superhydrophobic surface of the magnesium alloy substrate . The invention is energy-saving and environment-friendly, safe and efficient, simple in equipment, convenient in operation, not only does not need to consume electric energy, but also generates electric energy when processing the super-hydrophobic surface, and serves multiple purposes.

Description

A superhydrophobic surface of magnesium alloy substrate prepared by galvanic cell method

technical field

The invention relates to metal surface treatment, and relates to a process method for constructing a super-hydrophobic surface on a magnesium alloy substrate by using a galvanic battery method at room temperature.

background

Due to the characteristics of self-cleaning, anti-fouling, drag and friction reduction, and surface corrosion inhibition, super-hydrophobic surfaces have extremely broad application prospects in the fields of military, communications, aviation, energy, and biomedicine: using super-hydrophobic surfaces for high Satellite antennas, solar panels, and photoelectric converters in snowy areas can prevent major accidents such as signal interruptions caused by snow and freezing rain. Used on metal materials, it can play the role of self-cleaning, inhibiting surface corrosion and surface oxidation. The frictional resistance of the underwater vehicle during travel accounts for more than 80% of the total resistance. Using the super-hydrophobic surface on the shell of the submarine can reduce the resistance of the water, increase the speed of navigation, and save energy; On the surface, it can reduce the frictional resistance between the liquid flow and prevent adhesion and clogging; when used in microfluidic devices, it can achieve low resistance to fluid transmission without leakage; when used on micro water vehicles, it can make it It has super carrying capacity. Used in biomedical materials such as vascular stents in contact with blood, it can inhibit the adhesion and activation of platelets and improve the blood compatibility of materials. Used on the front inner wall of the aircraft engine compartment and the blades of the low-pressure compressor, it can reduce serious accidents such as air parking caused by engine icing; used on air conditioners and other related products, it can solve cold surface condensation, air source heat pumps and air coolers problems such as frosting. At present, super-hydrophobic surfaces can generally be prepared by two technical routes: one is to construct micro-nano-scale rough structures directly on the surface of low-surface-energy hydrophobic materials; the other is to use low-surface-energy materials on micro-nano-rough structures. Perform retouching. According to these two technical routes, researchers have prepared superhydrophobic surfaces on a variety of metal and non-metal materials.

Because magnesium alloy has the advantages of low density, high specific strength, large elastic modulus, and good shock absorption, it is widely used. The research on surface preparation technology of superhydrophobic magnesium alloy has also been paid attention to. Because the surface of magnesium alloy is a hydrophilic surface, two steps are required to prepare a superhydrophobic surface on a magnesium alloy substrate: one is roughening treatment, that is, a special method is used to construct a micro-nano rough structure on the surface; the other is low surface energy. Chemical treatment, that is, use low surface energy silane, fluorosilane or stearic acid to modify the obtained rough structure. Since Liang et al. prepared the superhydrophobic surface of magnesium alloy substrate in 2007 (Liang, J.; Guo, Z.G.; Fang, J.; Hao, J.C. Chemistry Letters 2007, 36, 416-417), a variety of methods have been used For the preparation of superhydrophobic surface of magnesium alloy substrate, these methods can be divided into: micro-arc oxidation method (Chinese patent 200710078089.3. , 21, 283-289), chemical etching method (Chinese patent 201010520898. Chinese patent 201010165310.0. Liu, K.S.; Zhang, M.L.; Zhai, J.; Wang, J.; Jiang, L. Applied Physics Letters 2008, 92, 183103. Wang, Y.H.; Wang, W.; Zhong, L.; Wang, J.; Jiang, Q.L.; Guo, X.Y. Applied Surface Science 2010, 256, 3837-3840. Yin, B.; , J.; Tang, A.Q.; Wei, W.H.; He, J. Applied Surface Science 2010, 257, 1666-1671.), chemical deposition (Ishizaki, T.; Saito, N. Langmuir 2010, 26, 9749-9755. Wang, J.; Li, D.D.; Gao, R.; Liu, Q.; Jing, X.Y.; Wang, Y.L.; ; Masuda, Y.; Sakamoto, M. Langmuir 2011, 27, 4780-4788.) and high-temperature hot water immersion (Ishizaki, T.; Sakamoto, M. Langmuir 2011, 27, 2375-2381). Although the hydrophobicity of the superhydrophobic surface of the magnesium alloy substrate prepared by the above method is good, there are still different problems: (1) the technical conditions required by the micro-arc oxidation method are relatively strict, and the operation is more troublesome; in the preparation of large-area superhydrophobic surface, a high-capacity power supply and a large monolithic cathode are required. (2) The chemical etching method needs to use corrosive liquids such as hydrochloric acid, sulfuric acid or nitric acid, and the working conditions are poor, and an irritating unpleasant smell will be produced during the processing, which is very harmful to the operator and the environment; during the reaction, the solution Wear and tear will occur, requiring constant replenishment of the dangerously corrosive fluids mentioned above. (3) The chemical deposition method requires the use of urea or cerium nitrate. Cerium nitrate is combustion-supporting and irritating, and can accumulate in groundwater for a long time, polluting groundwater; when urea is used, the processing time is longer, 12 hours. (4) Compared with the above three methods, the high-temperature hot water immersion method is a relatively environmentally friendly method, but it has the problem of low processing efficiency, and each processing requires several hours of processing time. Therefore, it is necessary to develop new safe, environmentally friendly, simple and efficient processing methods to prepare superhydrophobic surfaces of magnesium alloy substrates.

Contents of the invention

The technical problem to be solved by the present invention is to provide a safe, environment-friendly, simple and high-efficiency processing method to prepare the super-hydrophobic surface of the magnesium alloy substrate.

In order to solve the above-mentioned technical problems, the process method for constructing a super-hydrophobic surface on a magnesium alloy substrate provided by the invention comprises the following steps:

(1) Remove the oxide layer on the surface of the magnesium alloy plate and other metal plates, then use absolute ethanol and deionized water to ultrasonically clean the treated magnesium alloy plate and other metal plates in sequence, and dry them; other metals used include all Metals with higher electrode potential than magnesium;

(2) Place the magnesium alloy plate and other metal plates in parallel and symmetrically and connect them through wires, and then put them into a container filled with electrolyte to form a magnesium alloy-other metal primary battery; the electrolyte used is NaCl aqueous solution, NaBr Aqueous solution, Na ₂ SO ₄ aqueous solution or NaClO ₃ aqueous solution; the immersion time shall not be less than 15min, after immersion, rinse the magnesium alloy plate with deionized water and dry it;

(3) Put the above-mentioned magnesium alloy plate into an ethanol solution containing low surface energy materials for modification, take it out, dry it, and obtain the superhydrophobic surface of the magnesium alloy substrate after cooling to room temperature; the low surface energy materials used include fluorosilane , stearic acid, palmitic acid, lauric acid or myristic acid, etc.

Compared with the existing superhydrophobic surface preparation technology of magnesium alloy substrate, the present invention has the following advantages:

(1) The present invention does not require complex processing devices and operating steps, and is extremely easy to prepare in large areas.

(2) The present invention can use a neutral electrolyte without strong acid or alkali, no irritating gas is generated during the reaction process, and there is little harm to operators and the environment.

(3) The processing efficiency of the present invention is high, and the binary micro-nano rough structure required by the super-hydrophobic surface can be obtained in only a few tens of minutes.

(4) The superhydrophobic surface of the magnesium alloy substrate obtained in the present invention has good superhydrophobic performance, the contact angle to water is greater than 155°, and the rolling angle is less than 5°.

(5) The present invention does not need to consume electric energy in the preparation of the superhydrophobic surface, and at the same time forms a primary battery, and the electric energy generated can be used for power, lighting, communication, etc.

Description of drawings

Fig. 1 is the schematic diagram of the processing device of embodiment 1.

2 is a scanning electron micrograph of the superhydrophobic surface of the magnesium alloy substrate obtained in Example 1.

3 is a scanning electron micrograph of the superhydrophobic surface of the magnesium alloy substrate obtained in Example 1.

4 is a scanning electron micrograph of the superhydrophobic surface of the magnesium alloy substrate obtained in Example 1.

5 is a schematic diagram of the hydrophobicity of the superhydrophobic surface of the magnesium alloy substrate obtained in Example 1.

Detailed ways

Specific embodiments of the present invention will be described in detail below in conjunction with technical solutions and accompanying drawings.

Example 1

(1) Cut the magnesium alloy plate and copper plate into 20mm×30mm, the actual processing area is 20mm×20mm, and the rest is used for clamping and conducting. Before processing, first polish the magnesium alloy plate and copper plate with 1500# sandpaper to remove the oxide layer on the surface, and then use anhydrous ethanol and deionized water to ultrasonically clean the polished magnesium alloy plate and copper plate in sequence, the cleaning time is 2 minutes respectively, and blow dry.

(2) The magnesium alloy plate and the copper plate are fixed parallel and symmetrically, the distance between the two plates is 5 mm, and the two plates are connected by wires at the same time. Put the two plates into the 2mol/L NaCl aqueous solution, at this time the whole system forms a closed circuit, and the primary battery starts to work. During processing, the solution temperature is room temperature (about 25° C.), and the processing time is 60 minutes. Since the electrode potential of magnesium is lower than that of copper, the magnesium alloy will become the negative electrode and the oxidation reaction will occur.

(3) After the processing is completed, rinse the magnesium alloy plate with deionized water and dry it, and finally put it into the prepared fluorosilane ethanol solution with a mass fraction of 1%, soak it at room temperature for 2 hours, take it out, put it in In an oven, bake at 80°C for 15 minutes, take it out and cool it to room temperature in the air to obtain a super-hydrophobic surface. The contact angle of water droplets on the superhydrophobic surface of the magnesium alloy substrate is 162.8°, and the rolling angle is 2°. If stearic acid, palmitic acid, lauric acid or myristic acid are used to reduce the surface energy, the contact angle will exceed 150°.

Claims (1)

1. one kind prepares the magnesium alloy substrate super hydrophobic surface with galvanic cell method, it is characterized in that may further comprise the steps:

(1) zone of oxidation of removal magnesium alloy plate and other metal sheet surfaces is used absolute ethyl alcohol and deionized water ultrasonic cleaning to handling the back magnesium alloy plate successively with other metal sheets then, and is dried up; Described other metals comprise the metal that all electropotentials are higher than magnesium;

(2) the parallel symmetry with other metal sheets of magnesium alloy plate is placed, and it is continuous to pass through lead, puts it into then to constitute magnesiumalloy-other metal galvanic cells in the container that fills electrolytic solution; The electrolytic solution that is adopted is the NaCl aqueous solution, the NaBr aqueous solution, Na ₂SO ₄The aqueous solution or NaClO ₃The aqueous solution; Soak time is no less than 15min; After soaking completion magnesium alloy plate is used deionized water rinsing, and dry up;

(3) magnesium alloy plate that step (2) is obtained is put into the ethanolic soln that contains low-surface-energy material and is modified, and takes out the back oven dry, promptly obtains the magnesium alloy substrate super hydrophobic surface behind the cool to room temperature; The low-surface-energy material that is adopted comprises silicon fluoride, Triple Pressed Stearic Acid, palmitinic acid, LAURIC ACID 99 MIN or tetradecanoic acid.

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