Modified treatment liquid for preparing steel-based super-hydrophobic surface by chemical etching method as well as preparation and application methods of modified treatment liquid

Abstract

The invention belongs to the technical field of steel surface modification, and particularly relates to modification treatment liquid for preparing a steel-based super-hydrophobic surface through a chemical etching method and preparation and application methods of the modification treatment liquid. The etching agent is an inorganic salt, the modifier is an organic low-surface-energy substance, and the solvent is a mixture of water and an organic solvent; the molar concentration of the etching agent in the treating fluid is 0.3 mol / L to 1.2 mol / L, and the molar concentration of the modifying agent in the treating fluid is 0.01 mol / L to 0.1 mol / L. The method has the advantages that chemical etching and low surface energy modification are integrated in the same treating fluid, and one-step modification is realized. The complex process of cleaning, drying and re-modification after etching in a traditional two-step method is avoided, the operation steps are remarkably simplified, the production efficiency is improved, and the energy consumption is reduced.

Description

Technical Field

[0001] This invention belongs to the field of steel surface modification technology, and particularly relates to a modification treatment liquid for preparing superhydrophobic steel surfaces by chemical etching method, and its preparation and application methods. Background Technology

[0002] Low-alloy steel materials are widely used in the construction of ships, offshore platforms, bridges and other industries. Traditional low-alloy steel materials will encounter problems such as water condensation and icing and surface corrosion when exposed to humid environments during service. In particular, steel structures serving in extremely cold regions are prone to surface icing due to the characteristics of low temperature and high humidity service environment, which threatens service safety. At the same time, water and ice will also cause corrosion to steel materials.

[0003] In recent years, superhydrophobic materials have attracted widespread attention due to their unique superhydrophobic properties. Surfaces with a static contact angle with water greater than 150° are generally defined as superhydrophobic surfaces, which have application value in many areas such as self-cleaning, anti-fouling, anti-corrosion, and anti-icing. A micro / nano-layered structure and low surface energy are prerequisites for achieving superhydrophobic properties. Currently, superhydrophobic modification of steel surfaces is generally achieved by changing their surface roughness or by modifying them with low surface energy materials. Methods for superhydrophobic surface modification mainly include deposition methods, sol-gel methods, hydrothermal synthesis methods, chemical etching methods, template methods, and laser etching methods. Typically, a micro / nano-structure is first prepared on the surface, and then a superhydrophobic surface is obtained through modification with low surface energy materials. Among them, vapor deposition and laser etching require more sophisticated equipment, which is expensive and has low production efficiency, making them unsuitable for large-scale production; hydrothermal synthesis involves reactions in a sealed high-pressure autoclave, resulting in high energy consumption; template methods use soft or hard mold replication technology, which is not suitable for products with complex shapes and has certain limitations; chemical etching uses acidic or alkaline etching solutions for surface etching, resulting in lower production costs, simpler processes and equipment, and high feasibility for industrial applications.

[0004] Currently, the chemical etching method for superhydrophobic modification of steel surfaces typically employs a two-step process: first, chemical etching, followed by modification with a low surface energy material. This process involves additional steps such as cleaning and drying, making it complex. Developing a chemical etching method for preparing a modification solution for superhydrophobic steel surfaces, enabling one-step superhydrophobic modification, would improve production efficiency and reduce costs. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the purpose of this invention is to provide a modification treatment liquid for preparing superhydrophobic steel surfaces by chemical etching, and its preparation and application methods. This treatment liquid can achieve superhydrophobic modification of steel surfaces in one step, avoiding the complex operation of conventional chemical etching methods, saving costs and improving production efficiency and safety, and the obtained steel surface has superhydrophobic properties.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A chemical etching method is used to prepare a modification solution for superhydrophobic steel surfaces. The superhydrophobic steel modification solution is composed of an etchant, a modifier, and a solvent. The etchant is an inorganic salt, the modifier is an organic low surface energy substance, and the solvent is a mixture of water and an organic solvent. The molar concentration of the etchant in the treatment solution is 0.3~1.2 mol / L, and the molar concentration of the modifier in the treatment solution is 0.01~0.1 mol / L.

[0007] The modifier is a low surface energy substance of fatty acids.

[0008] The modifier is one of stearic acid, myristic acid, and palmitic acid.

[0009] The etching agent is an iron salt.

[0010] The organic solvent is at least one of ethanol, n-propanol, isopropanol, and acetone.

[0011] The volume ratio of water to organic solvent in the solvent is (0.1~1):1.

[0012] The steel in question is low-alloy steel.

[0013] A method for preparing a modification treatment liquid for preparing a steel-based superhydrophobic surface using chemical etching includes the following steps: 1) First, mix the depositing agent and the modifier evenly to obtain a solid mixture, then mix water and organic solvent to obtain a solvent, and finally mix the solid mixture and the solvent; 2) Dissolve solid substances using ultrasound at room temperature for 10-30 minutes to form a homogeneous solution; 3) Let the solution stand for 5-10 minutes to obtain the modified treatment solution for preparing the superhydrophobic surface of steel by chemical etching.

[0014] A method for applying a modification solution for preparing a superhydrophobic steel surface using a chemical etching method, wherein the modification solution achieves superhydrophobic modification of the steel surface through a one-step treatment, specifically including the following steps: 1) Steel surface pretreatment: Use 240~1200# wet sandpaper to sand the surface of the steel sample until the surface scratches are uniform, and then degrease, degrease and clean the surface of the steel sample with deionized water; 2) Treatment solution modification: The steel sample is placed in the modification treatment solution for modification treatment for 6 to 12 hours; 3) Cleaning: The modified steel sample was cleaned with water and then with ethanol in sequence; 4) Drying: After cleaning, the steel sample is dried at a temperature of 10~80℃ to obtain a superhydrophobic surface.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. The treatment solution prepared by this invention can impart superhydrophobic properties to ordinary steel materials. Moreover, the modified treatment solution components are inexpensive and readily available, do not use strong acids or alkalis, and have simple processing technology and low energy consumption, thus possessing economic and safety advantages.

[0016] 2. This invention integrates chemical etching and low surface energy modification into the same processing solution, achieving "one-step" modification. It avoids the complex process of post-etching cleaning, drying, and re-modification in the traditional two-step method, significantly simplifying the operation, improving production efficiency, and reducing energy consumption.

[0017] 3. The main components of the treatment solution are inorganic salts, low surface energy substances such as fatty acids, and common organic solvents. The raw materials are inexpensive and readily available. The process does not use hazardous chemicals such as strong acids or strong alkalis, and the process conditions are mild (normal temperature and pressure), possessing good economic efficiency and production safety.

[0018] 4. This invention utilizes the synergistic effect of chemical etching and organic modifiers to simultaneously construct the desired micro-nano rough structure on the steel surface and reduce its surface energy during the treatment process. Implementation examples show that the water contact angle of various treated low-alloy steel surfaces exceeds 150.0°, reaching a maximum of 160.0°, demonstrating excellent superhydrophobic properties.

[0019] 5. The steel surface obtained by using the modified treatment liquid of the present invention has a water contact angle of >150°, which has superhydrophobic properties and can significantly reduce the water contact angle. It meets the requirements of long-term waterproofing, anti-icing, anti-fouling and anti-corrosion in extremely cold and marine environments, and provides multiple protective effects on the steel surface. It is particularly suitable for low alloy steel structures such as ships, bridges and offshore platforms that are exposed to humid and cold environments, and can improve their service safety and durability. Attached Figure Description

[0020] Figure 1 This is a diagram of the water contact angle of the superhydrophobic surface in Example 1.

[0021] Figure 2 This is a surface icing diagram of the superhydrophobic surface in Example 1.

[0022] Figure 3 This is a diagram showing the self-cleaning and anti-fouling properties of the superhydrophobic surface in Example 1.

[0023] Figure 4 This is the corrosion electrochemical impedance spectroscopy of the superhydrophobic surface of Example 1.

[0024] Figure 5 This is the corrosion electrochemical potentiodynamic polarization curve of the superhydrophobic surface in Example 1. Detailed Implementation

[0025] The present invention will now be described in detail with reference to the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0026] Example 1: A chemical etching method is used to prepare a modification solution for a steel-based superhydrophobic surface. The solution comprises ferric chloride, stearic acid, water, and ethanol, with a ferric chloride concentration of 0.75 mol / L, a stearic acid concentration of 0.05 mol / L, and a water-to-ethanol volume ratio of 0.6:1. This modified solution was used to modify the surface of a ship plate A. The surface of plate A was degreased, cleaned with deionized water, and then polished with 240# wet sandpaper until the surface scratches were uniform. Plate A was then immersed in the modification solution for 8 hours, followed by sequential cleaning with deionized water and ethanol, and dried at room temperature to obtain a superhydrophobic steel surface for the ship plate A. The protective performance of the superhydrophobic surface in this embodiment was further tested and verified.

[0027] The test methods and results are as follows: Test methods: The water contact angle of an 8 μL deionized water droplet at ambient temperature was measured using a contact angle meter (OCA20LHT, Dataphysics Instruments, Germany). The anti-icing performance of the superhydrophobic surface at -20℃ was measured using a high and low temperature alternating damp heat test chamber (PL-3J, ESPEC, Japan). Liquid and solid contaminants were simulated using ink and silica powder, respectively. The simulated contaminants were evenly sprinkled on the superhydrophobic surface, and then water was dripped onto the surface using a dropper to examine the self-cleaning behavior and antifouling performance of the superhydrophobic surface. The corrosion electrochemical performance of the superhydrophobic surface in simulated seawater solution (3.5 wt% sodium chloride solution) was measured using a multi-channel electrochemical workstation (VeraStudio, Princeton, USA).

[0028] Test results: The water contact angle of the superhydrophobic surface of steel plate A is 153.7°, indicating superhydrophobic properties. Figure 1 Compared to the steel substrate of plate A, the superhydrophobic surface of plate A exhibits no significant surface icing, with an ice layer weight gain of only 19.68 g / m² per unit area. 2 The weight gain of ice layer per unit area of ​​the A-plate steel substrate is such that it has good anti-icing performance. Figure 2 The superhydrophobic surface of plate A carries away simulated contaminants during water droplet rolling, demonstrating excellent self-cleaning and anti-fouling properties. Figure 3 The superhydrophobic surface of plate A has a larger AC impedance spectrum radius, a higher self-corrosion potential, and a lower corrosion current density, exhibiting excellent corrosion resistance. (See...) Figure 4 , Figure 5 .

[0029] Example 2: A chemical etching method is used to prepare a modification solution for a superhydrophobic steel surface. The solution comprises ferric sulfate, ferrous chloride, palmitic acid, water, ethanol, and acetone. The concentrations of ferric sulfate, ferrous chloride, and palmitic acid are 0.3 mol / L and 0.01 mol / L, respectively. The volume ratio of ethanol to acetone in the ethanol-acetone mixture is 1:1, and the volume ratio of water to ethanol-acetone is also 1:1. This modification solution was used to modify the surface of bridge steel Q420qD to be superhydrophobic. The Q420qD surface was degreased, cleaned with deionized water, and then progressively polished with 240# to 600# sandpaper until the surface scratches were uniform. The Q420qD was then immersed in the modification solution for 12 hours, followed by sequential cleaning with deionized water and ethanol, and dried at 10°C to obtain a superhydrophobic steel surface with a water contact angle of 156.4°.

[0030] Example 3: A chemical etching method is used to prepare a modification solution for superhydrophobic steel surfaces. The solution comprises ferric nitrate, ferric chloride, myristic acid, water, and isopropanol, with ferric nitrate concentration of 0.6 mol / L, ferric chloride concentration of 0.4 mol / L, myristic acid concentration of 0.1 mol / L, and a water-to-isopropanol volume ratio of 0.3:1. This modification solution was used to modify marine engineering steel VL4-4 (FH32-FH690 / VL4-4 series) to produce a superhydrophobic surface. The VL4-4 surface was degreased, cleaned with deionized water, and progressively polished with 240# to 1200# sandpaper until the surface scratches were uniform. The VL4-4 was then immersed in the modification solution for 6 hours, followed by cleaning with deionized water and ethanol, and dried at 80°C to obtain a superhydrophobic VL4-4 steel surface with a water contact angle of 160.0°.

[0031] Example 4: A chemical etching method is used to prepare a modification solution for a steel-based superhydrophobic surface. The solution comprises ferric nitrate, stearic acid, water, and n-propanol, with ferric nitrate at a concentration of 0.3 mol / L, stearic acid at a concentration of 0.03 mol / L, and a water-to-propanol volume ratio of 0.1:1. This modification solution was used to modify the surface of ship plate steel AH36 to be superhydrophobic. The AH36 surface was degreased, cleaned with deionized water, and then progressively polished with 240# to 800# sandpaper until the surface scratches were uniform. The AH36 was then immersed in the modification solution for 6 hours, followed by sequential cleaning with deionized water and ethanol, and dried at room temperature to obtain a superhydrophobic steel surface with a water contact angle of 158.1°.

[0032] Example 5: A chemical etching method is used to prepare a modification solution for superhydrophobic steel surfaces. The solution comprises ferric sulfate, stearic acid, water, and acetone, with a ferric sulfate concentration of 1.2 mol / L, a stearic acid concentration of 0.1 mol / L, and a water-to-acetone volume ratio of 0.8:1. This modification solution was used to modify the surface of ship plate steel FH36 to be superhydrophobic. The FH36 surface was degreased, cleaned with deionized water, and then progressively polished with 240# to 1200# sandpaper until the surface scratches were uniform. The FH36 was then immersed in the modification solution for 9 hours, followed by cleaning with deionized water and ethanol, and dried at 50°C to obtain a superhydrophobic steel surface with a water contact angle of 157.7°.

[0033] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A modification solution for preparing a steel-based superhydrophobic surface using a chemical etching method, characterized in that, The superhydrophobic steel modification solution is composed of an etchant, a modifier, and a solvent; the etchant is an inorganic salt, the modifier is an organic low surface energy substance, and the solvent is a mixture of water and organic solvent; the molar concentration of the etchant in the solution is 0.3~1.2 mol / L, and the molar concentration of the modifier in the solution is 0.01~0.1 mol / L.

2. The modification solution for preparing a steel-based superhydrophobic surface using a chemical etching method according to claim 1, characterized in that, The modifier is a low surface energy substance of fatty acids.

3. The modification solution for preparing a steel-based superhydrophobic surface using a chemical etching method according to claim 1 or 2, characterized in that, The modifier is one of stearic acid, myristic acid, and palmitic acid.

4. The modification solution for preparing a steel-based superhydrophobic surface using a chemical etching method according to claim 1, characterized in that, The etching agent is an iron salt.

5. The modification solution for preparing a steel-based superhydrophobic surface using a chemical etching method according to claim 1, characterized in that, The organic solvent is at least one of ethanol, n-propanol, isopropanol, and acetone.

6. The modification solution for preparing a steel-based superhydrophobic surface using a chemical etching method according to claim 1, characterized in that, The volume ratio of water to organic solvent in the solvent is (0.1~1):

1.

7. The modification solution for preparing a steel-based superhydrophobic surface using a chemical etching method according to claim 1, characterized in that, The steel in question is low-alloy steel.

8. A method for preparing a modified treatment liquid for preparing a steel-based superhydrophobic surface using chemical etching as described in any one of claims 1-7, characterized in that, Includes the following steps: 1) First, mix the depositing agent and the modifier evenly to obtain a solid mixture, then mix water and organic solvent to obtain a solvent, and finally mix the solid mixture and the solvent; 2) Dissolve solid substances using ultrasound at room temperature for 10-30 minutes to form a homogeneous solution; 3) Let the solution stand for 5-10 minutes to obtain the modified treatment solution for preparing the superhydrophobic surface of steel by chemical etching.

9. A method for applying the modified treatment liquid for preparing a steel-based superhydrophobic surface using the chemical etching method as described in any one of claims 1-7, characterized in that, The modified treatment solution achieves superhydrophobic modification of steel surfaces through a one-step process, specifically including the following steps: 1) Steel surface pretreatment: Grind the surface of the steel sample with 240~1200# wet sandpaper, and then clean the surface of the steel sample with degreasing, grease removal and deionized water; 2) Treatment solution modification: The steel sample is placed in the modification treatment solution for modification treatment for 6 to 12 hours; 3) Cleaning: The modified steel sample was cleaned with water and then with ethanol in sequence; 4) Drying: After cleaning, the steel sample is dried at 10~80℃ to obtain a superhydrophobic surface.

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