A method for superhydrophobizing the surface of aluminum bronze and the aluminum bronze obtained thereby

Abstract

The application discloses a method for super-hydrophobic treatment of an aluminum bronze surface and aluminum bronze obtained by the method. The method comprises the following steps: using a ferric chloride hexahydrate hydrochloric acid solution as an etching solution, pretreating the aluminum bronze to remove oil stains and grease on the surface, then using the etching solution to chemically etch the pretreated aluminum bronze, and then blowing dry with cold air to obtain an aluminum bronze surface with a rough structure, and finally using heptadecafluorodecyltriethoxysilane to modify the aluminum bronze rough surface to self-assemble a super-hydrophobic film, thereby obtaining the super-hydrophobic surface of the aluminum bronze. Compared with the prior art, the method adopts a chemical etching method to construct a rough structure on the aluminum bronze surface, which is beneficial to the adsorption of heptadecafluorodecyltriethoxysilane, and the preparation process is simple, the conditions are mild, the stability is high, the method is green and environmentally friendly, and the prepared aluminum bronze super-hydrophobic surface has a contact angle of more than 160 degrees and good corrosion resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for super-hydrophobizing the surface of aluminum bronze and the aluminum bronze obtained. BACKGROUND

[0002] Aluminum bronze is an alloy formed by adding aluminum element in bronze, and is widely used in seawater pipes, valve systems, sonar devices, seawater external hatches, bearings and periscope assemblies. The marine environment is harsh, and seawater contains a large amount of salts and corrosion ions, which can easily cause corrosion of the equipment. In addition, in addition to the electrochemical corrosion of seawater, due to factors such as wind and wave current, biological adhesion, the equipment serving in the sea is also prone to cavitation corrosion, alternating stress corrosion and microbial corrosion. It is urgent to effectively improve the corrosion resistance of marine equipment. Although some surface modification methods have achieved remarkable protection effect, there are still some problems, such as: pollution, a large amount of wastewater is discharged during processing, causing secondary pollution, some are toxic and harmful, and have potential threat to marine organisms. High power consumption, excessive energy consumption, some equipment is precise and expensive, and it is difficult to mass-produce.

[0003] In recent years, super-hydrophobic surface has attracted widespread attention in the field of material corrosion and protection due to its special surface wetting effect, low pollution, environmental friendliness and multi-functionality. Through the preparation of super-hydrophobic surface, many excellent properties can be obtained, such as self-cleaning, anti-fogging, corrosion resistance, drag reduction, effective prevention of microbial adhesion and good anti-icing performance. In nature, many special surfaces such as lotus leaves, rice leaves, shark skin, moth eyes, crustaceans, rose petals and geckos exhibit excellent hydrophobicity and or super-hydrophobicity.

[0004] However, there are few methods for constructing super-hydrophobic surface of aluminum bronze at present, and these methods usually have the disadvantages of complex processing procedure, high cost and poor stability. SUMMARY

[0005] The present application is to solve the problems existing in the prior art and provide a method for super-hydrophobizing the surface of aluminum bronze and the aluminum bronze obtained.

[0006] The technical scheme adopted by the present application is:

[0007] A method for super-hydrophobizing the surface of aluminum bronze, comprising the following steps:

[0008] 1) using a mixed solution of ferric chloride hexahydrate and hydrochloric acid as etching solution;

[0009] 2) removing oil and grease on the surface of aluminum bronze;

[0010] 3) using the etching solution to chemically etch the aluminum bronze treated in step 2), and then rinsing and drying;

[0011] 4) placing the dried aluminum bronze in a solution of perfluorodecyl triethoxysilane, then taking out and modifying in an oven to obtain the aluminum bronze with a super-hydrophobic film surface, and completing the super-hydrophobic treatment of the aluminum bronze surface.

[0012] Further, the mass fraction of the ferric chloride hexahydrate is 3%-20%, and the concentration of the hydrochloric acid is 0.2 mol / L.

[0013] Further, in step 2), the oil dirt and grease removal method of the aluminum bronze surface is that the aluminum bronze is placed in anhydrous ethanol after polishing treatment, and then ultrasonic cleaning and deionized water rinsing are performed to remove the oil dirt and grease on the surface of the aluminum bronze.

[0014] Further, in the polishing treatment, the aluminum bronze is sequentially polished by 600-mesh and 1200-mesh metallographic sandpaper.

[0015] Further, in step 3), the chemical etching condition is that the etching is performed at 20-40℃ constant temperature water bath for 10-60 min.

[0016] Further, in step 4), the modification condition is that the modification is performed at 100-120℃ constant temperature for 120 min.

[0017] Further, in step 4), the molar concentration of the perfluorodecyl triethoxysilane is 1-3 mol / L.

[0018] Further, the contact angle of the super-hydrophobic film surface to water is 154°-168°, and the super-hydrophobic film surface has good corrosion resistance.

[0019] The application further discloses the aluminum bronze treated by the super-hydrophobic treatment method.

[0020] The application uses the ferric chloride solution as the etching solution, first performs pretreatment on the aluminum bronze to remove the oil dirt and grease on the surface, then performs chemical etching on the pretreated aluminum bronze by using the etching solution, and then performs cold air drying to obtain the aluminum bronze with a rough structure (which is beneficial to the adsorption of heptadecafluorodecyl triethoxysilane), and finally uses the heptadecafluorodecyl triethoxysilane to modify and self-assemble a super-hydrophobic film on the rough surface of the aluminum bronze, so that the super-hydrophobic surface of the aluminum bronze is obtained. On one hand, the process of the ferric chloride chemical etching is very mild, and the morphology change of the aluminum bronze surface can be effectively controlled; on the other hand, the cost of the ferric chloride is relatively low. The treatment process of the application is simple, and the cost is low, so that the technical problems of the prior art, such as the complex treatment process, the high cost and the poor stability of the super-hydrophobic surface of the aluminum bronze, are solved. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 Surface topography (5000 times) of the polished aluminum bronze.

[0022] Figure 2 Surface topography (5000 times) of the 6% mass fraction of ferric chloride hexahydrate etching for 40 min.

[0023] Figure 3 Surface topography (5000 times) of the 9% mass fraction of ferric chloride hexahydrate etching for 40 min.

[0024] Figure 4 Surface topography (5000 times) of the 12% mass fraction of ferric chloride hexahydrate etching for 40 min.

[0025] Figure 5 Surface topography (5000 times) of the 15% mass fraction of ferric chloride hexahydrate etching for 40 min.

[0026] Figure 6 The contact angle of the aluminum bronze without surface super-hydrophobic treatment.

[0027] Figure 7 , Figure 8 The contact angle of the aluminum bronze etched by the 12% and 15% mass fraction of ferric chloride hexahydrate for 40 min and modified.

[0028] Figure 9 The polarization curve of the aluminum bronze etched by the ferric chloride hexahydrate with different etching concentrations for 40 min and modified. DETAILED DESCRIPTION

[0029] The application will be further described below with reference to the accompanying drawings.

[0030] Example 1:

[0031] A method for super-hydrophobic treatment of an aluminum bronze surface, comprising the following steps:

[0032] 1) Preparation of etching solution: a mixed solution of ferric chloride hexahydrate and hydrochloric acid is prepared as the etching solution, the mass fraction of the ferric chloride hexahydrate is controlled to be 3%, and the concentration of the hydrochloric acid is controlled to be 0.2 mol / L;

[0033] 2) Pretreatment of the aluminum bronze: one piece of aluminum bronze is polished by 600-mesh and 1200-mesh metallographic sandpaper in sequence, and then is ultrasonically cleaned by anhydrous ethanol and deionized water in sequence to remove surface oil stains and grease; Figure 1 Surface topography (5000 times) of the polished aluminum bronze.

[0034] 3) Chemical etching: the pretreated aluminum bronze was immersed in the etching solution obtained in step 1) and etched in a water bath at 30℃ for 40 min, and then cleaned with a large amount of deionized water;

[0035] 4) The aluminum bronze obtained after etching in step 3) was hung in a reagent bottle, and perfluorodecyltriethoxysilane was dropped into the reagent bottle, and then placed in an oven at 120℃ for 120 min, and then taken out, thereby obtaining the super-hydrophobic surface of the aluminum bronze, and completing the super-hydrophobic treatment of the surface of the aluminum bronze.

[0036] Example 2:

[0037] Different from example 1, the mass fraction of the ferric chloride hexahydrate in this example was controlled to be 6%, and the concentration of the hydrochloric acid was controlled to be 0.2 mol / L. Figure 2 The surface morphology diagram (5000 times) of the 6% mass fraction ferric chloride hexahydrate etched for 40 min.

[0038] Example 3:

[0039] Different from example 1, the mass fraction of the ferric chloride hexahydrate in this example was controlled to be 9%, and the concentration of the hydrochloric acid was controlled to be 0.2 mol / L. Figure 3 The surface morphology diagram (5000 times) of the 9% mass fraction ferric chloride hexahydrate etched for 40 min.

[0040] Example 4:

[0041] Different from example 1, the mass fraction of the ferric chloride hexahydrate in this example was controlled to be 12%, and the concentration of the hydrochloric acid was controlled to be 0.2 mol / L. Figure 4 The surface morphology diagram (5000 times) of the 12% mass fraction ferric chloride hexahydrate etched for 40 min.

[0042] Example 5:

[0043] Different from example 1, the mass fraction of the ferric chloride hexahydrate in this example was controlled to be 15%, and the concentration of the hydrochloric acid was controlled to be 0.2 mol / L. Figure 5 The surface morphology diagram (5000 times) of the 15% mass fraction ferric chloride hexahydrate etched for 40 min.

[0044] Figure 6 The contact angle of the aluminum bronze without surface super-hydrophobic treatment.

[0045] Figure 7 、 Figure 8 The contact angles of the aluminum bronze etched for 40 min and modified by the 12% and 15% mass fraction ferric chloride hexahydrate, respectively.

[0046] According to Figure 4 、Figure 5 It can be seen that after etching by ferric chloride hexahydrate, a large number of needle-like and columnar structures appear on the surface of aluminum bronze, and after modification treatment by heptadecafluoro-1, 1, 2, 2-tetradecyltrichlorosilane, the super-hydrophobic surface can be formed, and a large number of needle-like and columnar structures can capture air and increase the hydrophobic angle of the surface.

[0047] Comparison Figure 6-8 It can be seen that the surface energy of the polished aluminum bronze is high due to oxidation, and the contact angle is low; and the surface energy of the aluminum bronze etched by 12% and 15% mass fraction ferric chloride hexahydrate for 40 min and modified is greatly reduced, so the contact angle is greatly improved to reach the super-hydrophobic state.

[0048] Figure 9 The polarization curves of different etching concentrations are shown in the figure, and it can be seen that after etching by 12% mass fraction ferric chloride hexahydrate for 40 min and 15% mass fraction ferric chloride hexahydrate for 40 min, the self-corrosion current density is obviously reduced.

[0049] In combination with Table 1, the corrosion resistance efficiency is improved and can reach 90.3% and 90.5% respectively. The super-hydrophobic surface usually has a special micro-nano structure, and the microstructure makes the surface have a large surface area, and the water droplets on the surface are highly spherical, reducing the contact area with the medium. The smaller contact area reduces the occurrence of electrochemical reaction, thereby reducing the self-corrosion current density. A dense protective layer is formed by modification of heptadecafluoro-1, 1, 2, 2-tetradecyltrichlorosilane, which blocks further corrosion reaction, and heptadecafluoro-1, 1, 2, 2-tetradecyltrichlorosilane has a lower conductivity, resists chemical reaction in the corrosion medium, thereby delaying the corrosion speed of the material, thereby reducing the self-corrosion current density.

[0050] Table 1 Electrochemical parameters of aluminum bronze hydrophobic surfaces prepared by different etching concentrations in 3.5% NaCl aqueous solution

[0051]

[0052] The scanning electron microscope is used for observing the surface morphology of the sample, and then the contact angle measuring instrument is used for measuring the contact angle of the water droplets on the super-hydrophobic surface.

[0053] Electrochemical analysis: The measurement of the polarization curve is completed in a three-electrode system, the working electrode is the aluminum bronze electrode with a constructed hydrophobic film, the auxiliary electrode and the reference electrode are respectively a Pt electrode and a saturated calomel electrode (SCE). The electrochemical test instrument is a Gamry electrochemical workstation. The polarization curve scanning range is-0.5-0.5V (vs. OCP), and the scanning speed is 1mV / s. The corrosion inhibition efficiency (η%) is calculated according to the following formula: η%=(I0-I) / I×100%.

[0054] where I0and I are the corrosion current densities of the untreated and hydrophobically treated aluminum bronze electrodes, respectively.

[0055] The above merely describes the preferred embodiments of the present application, and it should be pointed out that those skilled in the art can make several improvements without departing from the principles of the present application, and these improvements should also be considered as the protection scope of the present application.

Claims

1. A method of superhydrophobizing a surface of an aluminum bronze, characterized by: The method comprises the following steps: 1) using a mixed solution of ferric chloride hexahydrate and hydrochloric acid as etching solution; 2) removing oil dirt and grease on the surface of the aluminum bronze; 3) chemically etching the aluminum bronze treated in step 2) with the etching solution, then rinsing and drying; 4) placing the dried aluminum bronze in a solution of perfluorodecyltriethoxysilane, then taking out and modifying in an oven to obtain the aluminum bronze with super-hydrophobic film surface, and complete the super-hydrophobic treatment of the surface of the aluminum bronze; The mass fraction of the ferric chloride hexahydrate is 12% or 15%; The concentration of the hydrochloric acid is 0.2 mol / L; In step 2), the oil dirt and grease on the surface of the aluminum bronze is removed by placing the aluminum bronze treated by polishing in anhydrous ethanol and ultrasonic cleaning, then rinsing with deionized water; In the polishing treatment, the aluminum bronze is polished with 600-mesh and 1200-mesh metallographic sandpaper in sequence; In step 3), the chemical etching is performed under the condition of 30℃ constant temperature water bath for 40 min; In step 4), the modification is performed under the condition of 120℃ constant temperature for 120 min; In step 4), the molar concentration of the perfluorodecyltriethoxysilane is 1-3 mol / L; The contact angle of the super-hydrophobic film surface to water is 154°-168°.

2. The aluminum bronze treated by the method according to claim 1.

Images