A hydrophobic coating based on a core-shell structure of basalt nanosheet clusters and microspheres, its preparation method and application

Abstract

This invention discloses a hydrophobic coating based on a basalt nanosheet cluster microsphere core-shell structure, its preparation method, and its application. The coating comprises an adhesive / fluorinated basalt nanosheet cluster core-shell microsphere suspension composed of basalt nanosheets and an adhesive. The basalt nanosheets and the adhesive form a core-shell structure, with the adhesive core inside and the fluorinated basalt nanosheet clusters on the outside. The adhesive / fluorinated basalt nanosheet cluster core-shell microspheres possess a nearly isotropic layered micro / nano structure with a dense and rough nanoscale surface, containing low surface energy chemically inert components. The basalt nanosheets have a thickness of 1-10 nm and dimensions of 1-10 μm. It exhibits durable superhydrophobic properties, achieving long-lasting protection of the substrate.

Description

Technical Field

[0001] This invention belongs to the field of superhydrophobic coating technology, specifically relating to a hydrophobic coating based on a basalt nanosheet cluster microsphere core-shell structure, its preparation method, and its application. Background Technology

[0002] Superhydrophobic coatings are special surfaces that exhibit high contact angles (CA>150°) and low roll-off angles to liquids such as water and oil. Due to their unique wettability, superhydrophobic coatings have broad application prospects in fields such as corrosion prevention, anti-icing, and self-cleaning.

[0003] To date, researchers have developed various methods for preparing superhydrophobic coatings, such as sol-gel methods, etching methods, self-assembly methods, and vapor deposition methods. Although superhydrophobic coatings have broad application prospects in various fields, their poor durability severely limits their practical application. Researchers have developed several methods to improve the durability of superhydrophobic coatings, such as constructing micron-sized "armor" to protect nanostructures, constructing self-similar structures, and introducing binders. Among these methods, introducing binders to prepare durable superhydrophobic coatings is favored by researchers due to its advantages such as simple operation and large-area preparation.

[0004] Although significant progress has been made in improving the durability of superhydrophobic coatings by introducing binders, the introduction of binders usually embeds low surface energy nanoparticles, resulting in a high surface energy of the superhydrophobic coating. This causes microdroplets to be in a Wenzel state on the coating surface, causing the superhydrophobic coating to lose its functionality and severely limiting its practical application. Summary of the Invention

[0005] In order to overcome the problems existing in the prior art, the purpose of this invention is to provide a hydrophobic coating based on the core-shell structure of basalt nanosheet cluster microspheres, its preparation method and application, which has the characteristics of long-lasting superhydrophobicity and can achieve the purpose of long-lasting protection of the substrate.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A hydrophobic coating based on the core-shell structure of basalt nanosheet cluster microspheres includes an adhesive / fluorinated basalt nanosheet cluster core-shell microsphere suspension composed of basalt nanosheets and an adhesive.

[0008] The basalt nanosheets and the adhesive form a core-shell structure, with the adhesive core inside and fluorinated basalt nanosheet clusters on the outside.

[0009] The adhesive / fluorinated basalt nanosheet cluster core-shell microspheres possess a nearly isotropic, layered micro / nano structure with a dense yet rough nanoscale surface containing low-surface-energy chemically inert components (surface-modified fluorine bonds). The basalt nanosheets have a thickness of 1-10 nm and dimensions of 1-10 μm. The hydrophobic coating material with this basalt nanosheet cluster microsphere core-shell structure exhibits excellent pressure resistance, mechanical stability, and weather resistance.

[0010] A method for preparing a hydrophobic coating based on a basalt nanosheet cluster microsphere core-shell structure includes the following steps;

[0011] a. Preparation of basalt nanosheets: Basalt powder was placed in a hydrofluoric acid solution and stirred at a set temperature to carry out an etching reaction. After the reaction, the powder was filtered and washed to obtain basalt flakes with preliminary surface etching. The basalt flakes with preliminary surface etching were placed in a potassium hydroxide solution and stirred at a set temperature to carry out an etching reaction. After the reaction, the powder was filtered and washed to obtain basalt flakes with deep etching. The basalt flakes with deep etching were placed in a hydrofluoric acid solution and stirred at a set temperature to carry out an etching reaction. After the reaction, the powder was filtered and washed to obtain basalt nanosheets.

[0012] b. Fluorination treatment of basalt nanosheets: The basalt nanosheets are dissolved in an ethanol / water mixture to obtain a basalt nanosheet suspension. A set volume of perfluorododecyl polysiloxane solution is added to the suspension. The mixture is stirred at a set temperature to carry out the reaction. After the reaction is completed, a fluorinated basalt nanosheet suspension is obtained. After centrifugation, fluorinated basalt nanosheet powder is obtained.

[0013] c. Preparation of basalt nanosheet cluster microsphere core-shell structure: Polyolefin is dissolved in a set volume of n-butyl acetate and stirred evenly to obtain solution A; the fluorinated modified basalt nanosheet powder is slowly added to solution A and stirred to react. After the reaction is completed, a coating based on basalt nanosheet cluster microsphere core-shell structure can be obtained.

[0014] In step a, the concentration of hydrofluoric acid is above 40%; the concentration of potassium hydroxide solution is 0.1-1M; the ratio of the original basalt flakes to the hydrofluoric acid solution is (0.1-1g):30mL; the ratio of the basalt flakes with preliminary surface etching to the potassium hydroxide solution is (0.1-1g):20mL; the reaction temperature is 60-80℃; and the reaction time is 12-48h.

[0015] The purpose of this step is to etch and peel basalt flakes into basalt nanosheets.

[0016] In step b, the concentration of basalt nanosheets in the ethanol / water mixture is 10-100g per 1L of solvent, the volume ratio of ethanol to water is (0.5-1):1, the amount of perfluorododecyl polysiloxane added is 10-50mL per 1L of suspension, the reaction temperature is 40-80℃, and the reaction time is 12-48h.

[0017] The purpose of this step is to modify the surface of basalt nanosheets with fluorides, passivate the surface of the basalt nanosheets, and give them better hydrophobic properties.

[0018] In step c, the mass ratio of polyolefin to n-butyl acetate is (0.1-0.5):1, the mass ratio of fluorinated modified basalt nanosheet powder to solution A is (0.2-0.7):1, and the stirring time is 3-24h.

[0019] The purpose of this step is to create a hydrophobic coating on the core-shell structure of basalt nanosheet clusters microspheres.

[0020] The hydrophobic coating with the core-shell structure of the basalt nanosheet cluster microsphere can be used as a high-efficiency rain-proof coating for 5G / all-weather radomes and a waterproof coating for ancient brick and stone artifacts.

[0021] The beneficial effects of this invention are:

[0022] The preparation process of this invention is simple, and the prepared coating material has excellent pressure resistance, mechanical stability and weather resistance, and can be prepared on a large scale.

[0023] The adhesive / fluorinated modified basalt nanosheet cluster microsphere core-shell structure in this invention has an approximately isotropic layered micro / nano structure, a dense and rough nanoscale surface that contains chemically inert components with low surface energy, and exhibits excellent hydrophobic properties. Attached Figure Description

[0024] Figure 1 This is a schematic diagram illustrating the preparation process of the hydrophobic coating material with a core-shell structure of basalt nanosheet clusters and microspheres according to the present invention. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the embodiments.

[0026] Example 1

[0027] a. Preparation of basalt nanosheets: 1g of basalt powder was placed in 30mL of 40% hydrofluoric acid solution and etched at 60℃ for 12h with stirring. After the reaction, the nanosheets were filtered and washed to obtain pre-etched basalt flakes. 1g of the pre-etched basalt flakes was placed in 20mL of 1M potassium hydroxide solution and etched at 60℃ for 12h with stirring. After the reaction, the nanosheets were filtered and washed to obtain deeply etched basalt flakes. 0.5g of deeply etched basalt flakes was placed in 20mL of 40% hydrofluoric acid solution and etched at 60℃ for 12h with stirring. After the reaction, the nanosheets were filtered and washed to obtain basalt nanosheets.

[0028] b. Fluorination treatment of basalt nanosheets: 0.5g of basalt nanosheets were dissolved in 50mL of ethanol / water mixture to obtain a basalt nanosheet suspension. 0.5mL of perfluorododecyl polysiloxane solution was added to the suspension and the mixture was stirred at 40℃ for 12h. After the reaction was completed, a fluorinated basalt nanosheet suspension was obtained.

[0029] c. Preparation of basalt nanosheet cluster microsphere core-shell structure: 0.1 g of polyolefin was dissolved in 1 g of n-butyl acetate and stirred until homogeneous to obtain solution A. 0.2 g of fluorinated modified basalt nanosheet powder was slowly added to solution A and stirred for reaction. After 3 hours of reaction, a coating material suspension based on the basalt nanosheet cluster microsphere core-shell structure was obtained. Example 2

[0030] a. Preparation of basalt nanosheets: 0.1 g of basalt powder was placed in 30 mL of 40% hydrofluoric acid solution and etched at 60 °C for 12 h with stirring. After the reaction, the nanosheets were filtered and washed to obtain pre-etched basalt flakes. 0.1 g of the pre-etched basalt flakes were placed in 20 mL of 1 M potassium hydroxide solution and etched at 60 °C for 12 h with stirring. After the reaction, the nanosheets were filtered and washed to obtain deeply etched basalt flakes. 0.5 g of deeply etched basalt flakes were placed in 20 mL of 40% hydrofluoric acid solution and etched at 60 °C for 12 h with stirring. After the reaction, the nanosheets were filtered and washed to obtain basalt nanosheets.

[0031] b. Fluorination treatment of basalt nanosheets: 0.1 g of basalt nanosheets were dissolved in 50 mL of ethanol / water mixture to obtain a basalt nanosheet suspension. 0.5 mL of perfluorododecyl polysiloxane solution was added to the suspension and the mixture was stirred at 40 °C for 12 h. After the reaction was completed, a fluorinated basalt nanosheet suspension was obtained.

[0032] c. Preparation of basalt nanosheet cluster microsphere core-shell structure: 0.1 g of polyolefin was dissolved in 1 g of n-butyl acetate and stirred until homogeneous to obtain solution A. 0.1 g of fluorinated modified basalt nanosheet powder was slowly added to solution A and stirred for reaction. After 3 h of reaction, a coating material suspension based on the basalt nanosheet cluster microsphere core-shell structure was obtained.

[0033] Example 3

[0034] a. Preparation of basalt nanosheets: 0.1 g of basalt powder was placed in 30 mL of 40% hydrofluoric acid solution and etched at 80 °C for 24 h with stirring. After the reaction, the nanosheets were filtered and washed to obtain pre-etched basalt flakes. 0.1 g of the pre-etched basalt flakes were placed in 20 mL of 1 M potassium hydroxide solution and etched at 80 °C for 24 h with stirring. After the reaction, the nanosheets were filtered and washed to obtain deeply etched basalt flakes. 0.5 g of deeply etched basalt flakes were placed in 20 mL of 40% hydrofluoric acid solution and etched at 80 °C for 24 h with stirring. After the reaction, the nanosheets were filtered and washed to obtain basalt nanosheets.

[0035] b. Fluorination treatment of basalt nanosheets: 0.1 g of basalt nanosheets were dissolved in 50 mL of ethanol / water mixture to obtain a basalt nanosheet suspension. 0.5 mL of perfluorododecyl polysiloxane solution was added to the suspension and the mixture was stirred at 80 °C for 24 h. After the reaction was completed, a fluorinated basalt nanosheet suspension was obtained.

[0036] c. Preparation of basalt nanosheet cluster microsphere core-shell structure: 0.1 g of polyolefin was dissolved in 1 g of n-butyl acetate and stirred until homogeneous to obtain solution A. 0.1 g of fluorinated modified basalt nanosheet powder was slowly added to solution A and stirred for reaction. After 12 h of reaction, a coating material suspension based on the basalt nanosheet cluster microsphere core-shell structure was obtained.

[0037] Example 4

[0038] a. Preparation of basalt nanosheets: 0.5 g of basalt powder was placed in 30 mL of 40% hydrofluoric acid solution and etched at 60 °C for 12 h with stirring. After the reaction, the mixture was filtered and washed to obtain basalt flakes with preliminary surface etching. 0.5 g of the preliminarily etched basalt flakes were placed in 20 mL of 1 M potassium hydroxide solution and etched at 60 °C for 12 h with stirring. After the reaction, the mixture was filtered and washed to obtain deeply etched basalt flakes. 0.4 g of deeply etched basalt flakes were placed in 20 mL of 40% hydrofluoric acid solution and etched at 60 °C for 12 h with stirring. After the reaction, the mixture was filtered and washed to obtain basalt nanosheets.

[0039] b. Fluorination treatment of basalt nanosheets: 0.2g of basalt nanosheets were dissolved in 50mL of ethanol / water mixture to obtain a basalt nanosheet suspension. 0.5mL of perfluorododecyl polysiloxane solution was added to the suspension and the mixture was stirred at 40℃ for 12h. After the reaction was completed, a fluorinated basalt nanosheet suspension was obtained.

[0040] c. Preparation of basalt nanosheet cluster microsphere core-shell structure: 0.1 g of polyolefin was dissolved in 1 g of n-butyl acetate and stirred until homogeneous to obtain solution A. 0.1 g of fluorinated modified basalt nanosheet powder was slowly added to solution A and stirred for reaction. After 3 h of reaction, a coating material suspension based on the basalt nanosheet cluster microsphere core-shell structure was obtained.

[0041] Example 5

[0042] a. Preparation of basalt nanosheets: 0.5 g of basalt powder was placed in 30 mL of 40% hydrofluoric acid solution and etched at 80 °C for 24 h with stirring. After the reaction, the nanosheets were filtered and washed to obtain pre-etched basalt flakes. 0.5 g of the pre-etched basalt flakes were placed in 20 mL of 1 M potassium hydroxide solution and etched at 80 °C for 24 h with stirring. After the reaction, the nanosheets were filtered and washed to obtain deeply etched basalt flakes. 0.4 g of deeply etched basalt flakes were placed in 20 mL of 40% hydrofluoric acid solution and etched at 80 °C for 24 h with stirring. After the reaction, the nanosheets were filtered and washed to obtain basalt nanosheets.

[0043] b. Fluorination treatment of basalt nanosheets: 0.2g of basalt nanosheets were dissolved in 50mL of ethanol / water mixture to obtain a basalt nanosheet suspension. 0.5mL of perfluorododecyl polysiloxane solution was added to the suspension and the mixture was stirred at 80℃ for 24h. After the reaction was completed, a fluorinated basalt nanosheet suspension was obtained.

[0044] c. Preparation of basalt nanosheet cluster microsphere core-shell structure: 0.1 g of polyolefin was dissolved in 1 g of n-butyl acetate and stirred until homogeneous to obtain solution A. 0.1 g of fluorinated modified basalt nanosheet powder was slowly added to solution A and stirred for reaction. After 12 h of reaction, a coating material suspension based on the basalt nanosheet cluster microsphere core-shell structure was obtained.

[0045] From the appendix Figure 1 It can be seen that the core-shell structure of the basalt nanosheet cluster microsphere is composed of basalt nanosheet clusters, which has a rough surface structure. Fluorination modification of the nanosheet surface can further improve the hydrophobic properties of the coating material.

[0046] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a hydrophobic coating material based on basalt nanosheet cluster microsphere core-shell structure, characterized in that, Comprise the following steps: a. Preparation of basalt nanosheet: Put basalt powder in hydrofluoric acid solution, stir at a set temperature to carry out etching reaction, after the reaction is completed, perform suction filtration and washing to obtain preliminarily surface-etched basalt flake; Put the preliminarily surface-etched basalt flake in potassium hydroxide solution, stir at a set temperature to carry out etching reaction, after the reaction is completed, perform suction filtration and washing to obtain deeply etched basalt flake; Put the deeply etched basalt flake in hydrofluoric acid solution, stir at a set temperature to carry out etching reaction, after the reaction is completed, perform suction filtration and washing to obtain basalt nanosheet; b. Fluorination treatment of basalt nanosheet surface: Disperse the basalt nanosheet in ethanol / water mixed solution to obtain basalt nanosheet suspension, add a set volume of perfluorododecyl polysiloxane solution in the suspension, stir at a set temperature to carry out reaction, after the reaction is completed, obtain fluorinated modified basalt nanosheet suspension, and after centrifugal separation, obtain fluorinated modified basalt nanosheet powder; c. Preparation of basalt nanosheet cluster microsphere core-shell structure: Dissolve polyolefin in a set volume of n-butyl acetate, after uniform stirring, obtain solution A; Slowly add the fluorinated modified basalt nanosheet powder to solution A to stir and react, after the reaction is completed, obtain coating material based on basalt nanosheet cluster microsphere core-shell structure; The hydrophobic coating material based on basalt nanosheet cluster microsphere core-shell structure is an adhesive / fluorinated modified basalt nanosheet cluster core-shell microsphere suspension composed of basalt nanosheet and adhesive; The basalt nanosheet and adhesive form a core-shell structure, the inside is adhesive core, and the outside is fluorinated modified basalt nanosheet cluster; The adhesive / fluorinated modified basalt nanosheet cluster core-shell microsphere has approximately isotropic layered micro / nanoscale structure, nanoscale surface is dense and rough, and contains low-surface-energy chemical inert component; The basalt nanosheet has a size of 1-10 nm in thickness and 1-10 μm in length and width; In step a, the concentration of hydrofluoric acid is above 40%; the concentration of potassium hydroxide solution is 0.1-1 M; the dosage ratio of basalt powder to hydrofluoric acid solution is (0.1-1 g):30 mL; the dosage ratio of preliminarily surface-etched basalt flake to potassium hydroxide solution is (0.1-1 g):20 mL; the reaction temperature is 60-80℃; and the reaction time is 12-48 h.

2. The method of claim 1, wherein the method is characterized by: In step b, the concentration of basalt nanosheet in ethanol / water mixed solution is 10-100 g per 1 L of solvent; the volume ratio of ethanol to water is (0.5-1):1; the dosage of perfluorododecyl polysiloxane is 10-50 mL per 1 L of suspension; the reaction temperature is 40-80℃; and the reaction time is 12-48 h.

3. The method of claim 1, wherein the method is characterized by: In step c, the mass ratio of polyolefin to n-butyl acetate is (0.1-0.5):1; the mass ratio of fluorinated modified basalt nanosheet powder to solution A is (0.2-0.7):1; and the stirring time is 3-24 h.

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