CN111218712A

CN111218712A - Preparation method of super-hydrophobic surface of electrolytic copper matrix

Info

Publication number: CN111218712A
Application number: CN202010020966.7A
Authority: CN
Inventors: 高林松; 吕继组; 白敏丽
Original assignee: Dalian University of Technology
Current assignee: Dalian University of Technology
Priority date: 2020-01-09
Filing date: 2020-01-09
Publication date: 2020-06-02
Anticipated expiration: 2040-01-09
Also published as: CN111218712B

Abstract

The invention belongs to the technical field of materials, and provides a preparation method of a super-hydrophobic surface of an electrolytic copper matrix, wherein a micro-nano composite structure is formed on the surface of the copper matrix by adopting an electrolyte in an electrochemical corrosion mode, the surface shows super-hydrophobicity, and the processing parameters are as follows: the current density is 20mA/cm²～150mA/cm²The electrolysis time is 3min to 7min, and the distance between the two copper substrates is 50 mm. The electrolyte used in the preparation process is low in cost, environment-friendly, simple in preparation process and short in time consumption, the prepared copper surface has high super-hydrophobicity, and the contact angle can reach 160 degrees. And the superhydrophobicity can be stable after one month of storage under conventional conditions.

Description

Preparation method of super-hydrophobic surface of electrolytic copper matrix

Technical Field

The invention belongs to the technical field of materials, and relates to an electrochemical method for preparing a super-hydrophobic surface on a copper matrix.

Background

When the contact angle of the surface with water exceeds 150 degrees, the surface is called super-hydrophobic surface, and the proposal of the super-hydrophobic surface is inspired by natural structures (such as lotus leaves, mosquito compound eyes, butterfly wings, etc.). The super-hydrophobic surface can be applied to a plurality of fields of life, such as self-cleaning, boiling, flow resistance reduction and the like. The super-hydrophobic surface is applied to the surface of an inorganic substance to play a self-cleaning role; the super-hydrophobic surface is applied to a metal material, so that the superheat degree of surface initial boiling can be reduced; the application of a superhydrophobic surface to the flow within the tube facilitates reducing the resistance to fluid flow. Therefore, the preparation of stable superhydrophobic surfaces is of great practical significance.

With the development of the technology, researchers put forward a micro-nano structure composite mode aiming at pure copper materials and copper alloy materials. For example, the document HANG T, HU A, LING H, et al super-hydrophobic films with micro-nano structural preparation by electrochemical deposition [ J ]. applied surface Science,2010,256(8):2400-4. the micro-nano composite structure is formed on the copper surface by means of electrochemical plating, but the preparation requires strict chemical reaction conditions and surfactants. Researchers also propose to prepare a super-hydrophobic surface by a two-step method, and in the first step, the surface is pretreated by electrochemical, chemical or mechanical processing to form a micro-structure or a nano-structure; and secondly, modifying the pretreated surface by using a low-surface-energy material so as to obtain the super-hydrophobic surface. Patent application numbers 201811261946.8 and 201110358253.2 use an electrochemical method to produce a nano structure on the surface of a copper matrix in an electrolytic way, and then use a low surface energy material to carry out surface modification, thereby obtaining a super-hydrophobic surface. However, this method uses many chemical reagents, and the low surface energy material is very unstable and is prone to failure in practical applications. Therefore, it is important to develop a simple, efficient and safe method for preparing a stable superhydrophobic surface on a pure copper substrate.

Disclosure of Invention

The invention aims to solve the problems of poor stability, complex flow and the like in the existing super-hydrophobic surface preparation, and provides a super-hydrophobic surface preparation method of an electrolytic copper matrix.

The technical scheme of the invention is as follows:

a method for preparing a super-hydrophobic surface of an electrolytic copper matrix comprises the following steps:

step one, polishing a copper matrix smoothly by using 800, 1500 and 3000-mesh water sand paper in sequence to remove an oxide layer on the surface of the copper matrix, then washing the polished copper matrix cleanly by using deionized water and absolute ethyl alcohol in sequence, and drying the copper matrix in a vacuum drying oven at the temperature of 50 ℃ for later use;

adding potassium chloride and nickel chloride into deionized water, and uniformly stirring to obtain electrolyte, wherein the concentration of potassium chloride in the electrolyte is 0.7-1.5 mol/L, and the concentration of nickel chloride is 0.7-1.5 mol/L;

step three, placing the electrolyte obtained in the step two in an electrolytic cell, connecting the copper substrates obtained in the two steps as an anode and a cathode respectively with the anode and the cathode of a direct current power supply, adjusting the two copper substrates to be placed in parallel with the opposite directions, adjusting the distance between the two copper substrates to be 50m, turning on the direct current power supply, and controlling the current density to be 20mA/cm²～150mA/cm²Electrolyzing for 3-7 min;

and step four, cleaning the electrolyzed anode copper matrix in the step three by using absolute ethyl alcohol and deionized water in sequence, then placing the washed anode copper matrix in the absolute ethyl alcohol to soak for more than 2 hours, and then placing the anode copper matrix in a vacuum drying oven at 50 ℃ to dry, wherein the dried anode copper matrix presents super-hydrophobicity. The contact angle of the super-hydrophobic copper surface prepared by adopting the electrolysis mode can reach 160 degrees.

The invention has the beneficial effects that:

(1) the used electrolyte has low cost, is environment-friendly, and has simple preparation process and short time consumption.

(2) The super-hydrophobicity is caused by the micro-nano composite structure formed on the copper substrate in the mode of the invention, the contact angle can reach 160 degrees, and the super-hydrophobicity can be kept stable after the copper substrate is placed for one month under the conventional condition.

(3) The method for preparing the copper matrix super-hydrophobic surface by adopting the electro-corrosion mode belongs to a one-step preparation mode, and does not need low surface energy coating modification.

Drawings

Fig. 1 is a scanning electron microscope image of a superhydrophobic surface prepared in example 1 of the present invention.

FIG. 2 is a scanning electron micrograph of the superhydrophobic surface prepared in example 3 of the present invention.

Detailed Description

The following further describes a specific embodiment of the present invention with reference to the drawings and technical solutions.

Example 1

Step one, two copper substrates with the size of 50mm multiplied by 10mm multiplied by 1mm are sequentially polished by 800, 1500 and 3000-mesh water sand paper until the surfaces are smooth, so as to remove an oxide layer on the surfaces of the copper substrates. Then, washing the polished copper substrate with deionized water and absolute ethyl alcohol in sequence, and drying the copper substrate in a vacuum drying oven at the temperature of 50 ℃ for later use;

step two, dissolving 47.54g of nickel chloride hexahydrate and 14.9g of potassium chloride powder in deionized water, fixing the volume to 200mL, and uniformly stirring to obtain electrolyte with the nickel chloride concentration of 1mol/L and the potassium chloride concentration of 1 mol/L;

step three, placing the electrolyte in the step two in an electrolytic cell, connecting the two copper substrates dried in the step one as an anode and a cathode respectively with the anode and the cathode of a programmable direct current power supply, adjusting the two copper substrates to be placed in parallel with the opposite sides of the two copper substrates at a distance of 50mm, turning on the programmable direct current power supply, and controlling the current density to be 50mA/cm²Electrolyzing for 5min under the condition of (1);

and step four, cleaning the electrolyzed anode copper matrix in the step three by using absolute ethyl alcohol and deionized water in sequence, then placing the washed anode copper matrix in the absolute ethyl alcohol to soak for more than 2 hours, and then placing the anode copper matrix in a vacuum drying oven at 50 ℃ to dry, wherein the surface of the dried anode copper matrix presents super-hydrophobicity.

Fig. 1 is an electron microscope scanning image of the superhydrophobic surface prepared in this embodiment, and it can be seen from the image that the sheet structures are uniformly distributed on the surface of the substrate, and the sheet structures form a complex micro-nano composite structure, which greatly increases the capacity of storing air, thereby realizing the superhydrophobicity of the surface of the copper matrix.

Example 2

dissolving 33.28g of nickel chloride hexahydrate and 10.43g of potassium chloride powder in deionized water, fixing the volume to 200mL, and uniformly stirring to obtain electrolyte with the nickel chloride concentration of 0.7mol/L and the potassium chloride concentration of 0.7 mol/L;

step three, placing the electrolyte in the step two in an electrolytic cell, connecting the two copper substrates dried in the step one as an anode and a cathode respectively with the anode and the cathode of a programmable direct current power supply, adjusting the two copper substrates to be placed in parallel with the opposite sides of the two copper substrates at a distance of 50mm, turning on the programmable direct current power supply, and controlling the current density to be 100mA/cm²Electrolyzing for 7min under the condition of (1);

Example 3

step two, dissolving 71.31g of nickel chloride hexahydrate and 22.35g of potassium chloride powder in deionized water, fixing the volume to 200mL, and uniformly stirring to obtain electrolyte with the nickel chloride concentration of 1.5mol/L and the potassium chloride concentration of 1.5 mol/L;

step three, placing the electrolyte in the step two in an electrolytic cell, connecting the two copper substrates dried in the step one as an anode and a cathode respectively with the anode and the cathode of a programmable direct current power supply, adjusting the two copper substrates to be placed in parallel with the opposite directions, adjusting the distance between the two copper substrates to be 50mm, and opening the programmable direct current power supplyPower supply at a current density of 35mA/cm²Electrolyzing for 5min under the condition of (1);

Fig. 2 is a scanning electron microscope image of the superhydrophobic surface prepared in this embodiment, and it can be seen from the image that peak-like and sheet-like staggered structures are formed on the surface of the substrate, and these structures are also complex micro-nano composite structures, so that the superhydrophobicity of the surface of the copper substrate is realized.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and any simple modifications to the above embodiment are possible in accordance with the technical spirit of the present invention. Modifications and equivalent structural changes are also within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a super-hydrophobic surface of an electrolytic copper matrix is characterized by comprising the following steps:

step one, polishing a copper substrate by using water sand paper to remove an oxide layer on the surface of the copper substrate, then sequentially washing the polished copper substrate by using deionized water and absolute ethyl alcohol, and drying the copper substrate in a vacuum drying oven at the temperature of 50 ℃ for later use;

and step four, cleaning the electrolyzed anode copper matrix in the step three by using absolute ethyl alcohol and deionized water in sequence, then placing the washed anode copper matrix in the absolute ethyl alcohol to soak for more than 2 hours, and then placing the anode copper matrix in a vacuum drying oven at 50 ℃ to dry, wherein the dried anode copper matrix presents super-hydrophobicity.