CN110484065A - A kind of preparation method of the super-amphiphobic coating suitable for various soft hard substrates based on fluorided silica silicon particle - Google Patents

Abstract

The invention relates to a method for preparing a super-amphiphobic coating suitable for various soft and hard substrates based on fluorinated silica particles. Organic coatings with superhydrophobic and superoleophobic properties. Due to the lack of substrate dependence, the coating can be coated on various soft and hard substrates by spraying or dipping and exhibits good superhydrophobic properties. Organic liquids with a surface energy as low as 28.7mN/m can also maintain a spherical shape on the surface coated with this layer and maintain a contact angle above 150°. When a dynamic droplet hits a flat surface at a certain speed, the droplet bounces on the surface in the form of a cake until the kinetic energy is exhausted. On an inclined surface, the droplet can also roll on the surface or leave in a bouncing manner with a rolling angle of less than 10° surface. Even after being treated under harsh conditions such as high temperature, acid and alkali, the coated surface still exhibits good self-cleaning and antifouling functions.

Description

A fluorinated silica particle-based ultra-dual coating for a variety of soft and hard substrates The preparation method of sparse coating

technical field

The invention belongs to the technical field of preparation of durable super-amphiphobic coatings, in particular to a preparation method of super-amphiphobic coatings suitable for various soft and hard substrates based on fluorinated silicon dioxide particles.

Background technique

The artificial surface in the natural environment is easily polluted by solid or liquid fluid due to its low wettability. The damage to the surface caused by various pollution is mostly irreversible and the repair cost is high. Therefore, in recent years, inspired by The high anti-wetting properties of various animal and plant surfaces in nature, the theory and application of biomimetic anti-wetting materials have received extensive attention from academia and industry, and a variety of artificial anti-wetting surfaces have been successfully prepared. Among them, the superamphiphobic surface is one of the most concerned objects and one of the most promising directions. A superamphiphobic surface refers to a surface that has a contact angle of greater than 150° and a rolling angle of less than 10° for both water droplets and low surface energy oil droplets. Compared with traditional superhydrophobic surfaces, superamphiphobic surfaces have more extensive applications in fluid control, self-cleaning and anti-fouling, liquid transportation, etc.

Reducing the surface energy of substrates and finely constructing rough structures by chemical modification with very low surface energy modifiers are general methods for preparing superamphiphobic surfaces. In the present invention, silicon dioxide particles with two particle sizes of micro and nanometers are used to construct a multi-level composite rough structure and supplemented with 3-aminopropyltriethoxysilane and perfluorooctanoic acid to reduce surface energy, and polyvinylidene fluoride-hexafluoropropylene Enhance the adhesion between the particles and the substrate and further reduce the surface energy, which not only ensures the stability of the surface structure but also makes the surface more resistant to wetting by low surface energy liquids. The coating is applied on the surface of the substrate by simple and easy methods of spraying and dipping, which is convenient for large-scale preparation and production of the super-amphiphobic surface. Based on this, the durable superamphiphobic coating prepared by the present invention can achieve high wetting resistance of water droplets and oil droplets, which is conducive to enriching the preparation methods of superamphiphobic surfaces and expanding the application of superamphiphobic surfaces in fluid control and antifouling. application.

Contents of the invention

The purpose of the present invention is to provide a method for preparing super-amphiphobic coatings suitable for various soft and hard substrates based on fluorinated silicon dioxide particles.

The technical solution for realizing the object of the present invention is: a method for preparing a super amphiphobic coating suitable for various soft and hard substrates based on fluorinated silicon dioxide particles, characterized in that it comprises the following steps:

A. Silica sol preparation: Mix nano-silica and micro-silica in a certain proportion, disperse them in a certain amount of ethanol solution and stir them magnetically for a period of time, then mix a certain amount of 3-aminopropyl triethyl Oxysilane is added to the mixed solution at room temperature and magnetically stirred for a period of time, and finally a certain amount of perfluorooctanoic acid and 1-ethyl-(3-dimethylaminopropyl) carbodiimide are respectively added to the mixed solution and heated at a certain temperature After reacting for a period of time, the particle sol can be obtained;

B. Preparation of solid fluorinated particles: cooling the obtained sol to room temperature and centrifuging to separate solid particles, washing with ethanol twice to remove excess solvent and unreacted modifier, and drying at a certain temperature;

C. Preparation of super-amphiphobic coating: Dissolve a certain amount of polyvinylidene fluoride-hexafluoropropylene in a certain amount of N,N-dimethylformamide with magnetic stirring, and add a certain amount of n-octylamine to the solution. Add a certain amount of fluorinated silicon dioxide particles, and stir magnetically for a period of time to obtain a light yellow mixed solution;

D. Preparation of super-amphiphobic surface: Soak the substrate material in a mixed solution of ethanol and acetone for a certain period of time and then dry it for later use. Add an appropriate amount of light yellow mixed solution into the spray gun and spray it on the hard substrate. Use dip coating The way to apply coatings on soft substrates.

Further, in step A, the ratio of raw material parts by mass is: silicon dioxide: 3-aminopropyltriethoxysilane: perfluorooctanoic acid: 1-ethyl-(3-dimethylaminopropyl) carbodiimide The ratio of the amount of ethanol solution to silicon dioxide is 20:5:5:1, the ratio of the amount of ethanol solution to silicon dioxide is 20ml:1g, and the silicon dioxide is a combination of nanometer silicon dioxide and micron silicon dioxide in different proportions.

Further, in step A, the mass ratios of nano-silica and micro-silica selected are 4:0, 3:1, 2:2, and 1:3, respectively.

Further, in step A, the particle sizes of nano-silica and micro-silica are 15-25nm and 0.5-1 μm respectively, the magnetic stirring time of 3-aminopropyltriethoxysilane is 2-4h, and perfluorooctanoic acid and 1 -Ethyl-(3-dimethylaminopropyl)carbodiimide is added to the mixed solution for a reaction time of 6-10 hours, and a reaction temperature of 75-90°C.

Further, the drying temperature in step B and step D is 65°C.

Further, in step C, the ratio of polyvinylidene fluoride-hexafluoropropylene, N,N-dimethylformamide to n-octylamine in parts by mass is: 1:30:1.

Further, the superamphiphobic coating is applicable to various soft substrates and hard substrate materials, including cloth, filter paper, PET flakes, sponge and glass.

The beneficial effect of the present invention is: compared with prior art, the present invention has the advantage that:

1. The adhesion between the coating and the substrate is good, and the structure and chemical composition are stable.

2. Excellent coating resistance and thermal stability.

3. The coating has no substrate dependence and is suitable for various soft and hard substrates.

4. The coating can be applied to the surface of the substrate by a simple method of spin coating or dip coating and endows the substrate with good super-hydrophobic properties.

Description of drawings

Figure 1 shows the wettability (a-b) of water droplets, ethylene glycol, and o-xylene on the surface controlled by changing the weight ratio of micro-nano particles in Example 1 of the present invention, and water droplets (c) and o-xylene (d) are coated on the surface. V-bounce, water droplet and o-xylene adhesion tests on coated glass surfaces (e–f).

Fig. 2 is the wettability (a) and the corresponding contact angle test (b) of liquid droplets with different surface tensions on the glass surface in Example 2 of the present invention.

Fig. 3 is that in embodiment 2 of the present invention, coating is coated on various substrates respectively and the wettability of the droplet of measuring various surface tensions on the surface: (a) PET, (b) stainless steel, (c) paper sheet, (d) sponge, (e) cloth; (f) o-xylene rolled on a curled cloth.

Fig. 4 is the pie-shaped bouncing of water drop and o-xylene on the surface of cloth (a), paper (b) and glass (c) placed flat in Example 3 of the present invention, (d) water drop on the inclined glass surface Inelastic bounce.

Figure 5 shows the changes in surface wettability of water droplets and crude oil under different treatment conditions in Example 4 of the present invention (a) leave the surface at room temperature for 3-18 days, (b) place the surface in water for 3-48 hours , (c) put the surface in the solution of pH 2-14 for 30 minutes, (d) put the surface in the environment of 60-140 ℃ for 2 hours, (e) the thermogravimetric curve of the coating, (f-g) respectively The rolling situation of water droplets and crude oil on the surface after the surface is placed in an environment of 140°C for 2 hours.

Detailed ways

In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with the examples, but the content of the present invention is not limited to the following examples. Those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms are also within the scope of the claims listed in this application.

Example 1

1. Preparation of silica sol: Different content of micro-nano particles will affect surface roughness and surface wettability. In this invention, surfaces with different oleophobic properties are prepared by adjusting the mass ratio of micro-nano silica. 2g of silicon dioxide was mixed with 40ml of ethanol and then magnetically stirred at room temperature for 30 minutes, wherein 2g of silicon dioxide was selected from a combination of nanometer silicon dioxide and micrometer silicon dioxide in different proportions. The selected nano-silica and micro-silica are respectively 4:0, 3:1, 2:2, and 1:3 in mass ratio, that is, the amounts of nano-silica and micro-silica are: 2g and 0g, 1.5g and 0.5g, 1g and 1g, 0.5g and 1.5g; then 0.5g of 3-aminopropyltriethoxysilane was added to the mixed solution at room temperature and magnetically stirred for 2 hours. Finally, 0.5 g of perfluorooctanoic acid and 0.1 g of 1-ethyl-(3-dimethylaminopropyl) carbodiimide were respectively added into the mixed solution and reacted at 75° C. for 6 hours to obtain the particle sol.

2. Preparation of solid fluorinated particles: Cool the obtained sol to room temperature and centrifuge to separate solid particles, wash with ethanol twice to remove excess solvent and unreacted modifier, and dry at 65°C.

3. Preparation of super-amphiphobic coating: Dissolve 1g of polyvinylidene fluoride-hexafluoropropylene in 30g of N,N-dimethylformamide with magnetic stirring, add 1g of n-octylamine to it, and add 2g of fluorine to the solution SiO2 particles were synthesized and magnetically stirred for 2 hours to obtain a light yellow mixed solution.

4. Superamphiphobic surface preparation: Soak all substrates (cloth, filter paper, PET flakes, sponge, glass) in a mixed solution of ethanol and acetone for 20 minutes and then dry them for later use. Add an appropriate amount of light yellow mixed solution to the spray gun In, spray on hard substrates, and apply coatings on soft substrates by dipping.

5. Regulate surface wettability through micro-nano mass ratio, that is, droplet adhesion test: water droplets, ethylene glycol, and o-xylene have the largest contact angle on the surface with a mass ratio of nano-SiO ₂ : micron-SiO ₂ = 3:1 And the lowest rolling angle, the surface of 3:1 shows the best wetting resistance, when both water droplets and o-xylene are injected onto the surface at a rapid angle, the droplets can be sputtered from the surface without Adheres to surfaces.

Example 2

1. Preparation of silica sol: Different content of micro-nano particles will affect surface roughness and surface wettability. In this invention, surfaces with different oleophobic properties are prepared by adjusting the mass ratio of micro-nano silica. Mix 4g of silicon dioxide with 80ml of ethanol and stir magnetically at room temperature for 30 minutes, wherein the proportions of nanometer silicon dioxide and micrometer silicon dioxide are 4g and 0g, 3g and 1g, 2g and 2g, 1g and 3g respectively, and then 1g of 3 -Aminopropyltriethoxysilane was added to the mixed solution and stirred magnetically at room temperature for 3 hours. Finally, 1 g of perfluorooctanoic acid and 0.2 g of 1-ethyl-(3-dimethylaminopropyl) carbodiimide were respectively added into the mixed solution and reacted at 75° C. for 6 hours to obtain the particle sol.

2. Preparation of solid fluorinated particles: Cool the obtained sol to room temperature and centrifuge to separate solid particles, wash with ethanol twice to remove excess solvent and unreacted modifier, and dry at 65°C.

3. Preparation of super-amphiphobic coating: Dissolve 1 g of polyvinylidene fluoride-hexafluoropropylene in 30 g of N,N-dimethylformamide with magnetic stirring, add 1 g of n-octylamine to it, and add 2 g of it to the solution Silica particles were fluorinated and magnetically stirred for 2 hours to obtain a light yellow mixed solution.

4. Superamphiphobic surface preparation: Soak all substrates (cloth, filter paper, PET flakes, sponge, glass) in a mixed solution of ethanol and acetone for 20 minutes and then dry them for later use. Add an appropriate amount of light yellow mixed solution to the spray gun In, spray on hard substrates, and apply coatings on soft substrates by dipping.

5. The wettability of droplets with various surface tensions on superamphiphobic surfaces and the substrate-free dependence of coatings: water droplets, glycerol, ethylene glycol, crude oil, ortho-xylene on coated glass The surface has a contact angle greater than 150°, and compared with the substrate without the coating, the surface of the coated PET plate, stainless steel, paper, cloth, and sponge has good water and oil resistance of wetting.

Example 3

1. Preparation of silica sol: Different content of micro-nano particles will affect surface roughness and surface wettability. In this invention, surfaces with different oleophobic properties are prepared by adjusting the mass ratio of micro-nano silica. Mix 2g of silicon dioxide with 40ml of ethanol and stir magnetically at room temperature for 30 minutes, wherein the proportions of nanometer silicon dioxide and micrometer silicon dioxide are 2g and 0g, 1.5g and 0.5g, 1g and 1g, 0.5g and 1.5g respectively , and then 0.5 g of 3-aminopropyltriethoxysilane was added to the mixed solution at room temperature and magnetically stirred for 3 hours. Finally, 0.5 g of perfluorooctanoic acid and 0.1 g of 1-ethyl-(3-dimethylaminopropyl) carbodiimide were respectively added into the mixed solution and reacted at 85° C. for 8 hours to obtain the particle sol.

2. Preparation of solid fluorinated particles: Cool the obtained sol to room temperature and centrifuge to separate solid particles, wash with ethanol twice to remove excess solvent and unreacted modifier, and dry at 65°C.

3. Preparation of super-amphiphobic coating: Dissolve 1 g of polyvinylidene fluoride-hexafluoropropylene in 30 g of N,N-dimethylformamide with magnetic stirring, add 1 g of n-octylamine to it, and add 2 g of it to the solution Silica particles were fluorinated and magnetically stirred for 2 hours to obtain a light yellow mixed solution.

4. Superamphiphobic surface preparation: Soak all substrates (cloth, filter paper, PET flakes, sponge, glass) in a mixed solution of ethanol and acetone for 20 minutes and then dry them for later use. Add an appropriate amount of light yellow mixed solution to the spray gun In, spray on hard substrates, and apply coatings on soft substrates by dipping.

5. Droplet bouncing on a superamphiphobic surface in a cake-like manner: After a water droplet and o-xylene fall at a height of 5 cm and collide with coated glass, paper and cloth substrates, the droplet undergoes multiple inelastic collisions on the surface After resting, it bounces off the surface in a pie-like bounce.

Example 4

1. Preparation of silica sol: Different content of micro-nano particles will affect surface roughness and surface wettability. In this invention, surfaces with different oleophobic properties are prepared by adjusting the mass ratio of micro-nano silica. Mix 4g of silicon dioxide with 80ml of ethanol and stir magnetically at room temperature for 30 minutes, wherein the proportions of nanometer silicon dioxide and micrometer silicon dioxide are 4g and 0g, 3g and 1g, 2g and 2g, 1g and 3g respectively, and then 1g of 3 -Aminopropyltriethoxysilane was added to the mixed solution at room temperature and magnetically stirred for 4 hours. Finally, 1 g of perfluorooctanoic acid and 0.2 g of 1-ethyl-(3-dimethylaminopropyl) carbodiimide were respectively added into the mixed solution and reacted at 95° C. for 10 hours to obtain the particle sol.

2. Preparation of solid fluorinated particles: Cool the obtained sol to room temperature and centrifuge to separate solid particles, wash with ethanol twice to remove excess solvent and unreacted modifier, and dry at 65°C.

3. Preparation of super-amphiphobic coating: Dissolve 1 g of polyvinylidene fluoride-hexafluoropropylene in 30 g of N,N-dimethylformamide with magnetic stirring, add 1 g of n-octylamine to it, and add 2 g of it to the solution Silica particles were fluorinated and magnetically stirred for 2 hours to obtain a light yellow mixed solution.

4. Superamphiphobic surface preparation: Soak all substrates (cloth, filter paper, PET flakes, sponge, glass) in a mixed solution of ethanol and acetone for 20 minutes and then dry them for later use. Add an appropriate amount of light yellow mixed solution to the spray gun In, spray on hard substrates, and apply coatings on soft substrates by dipping.

5. Test the durability of the super-amphiphobic surface: the coated glass was left at room temperature for 18 days, immersed in water for 48 hours, immersed in different pH solutions for 30 minutes, and left at different temperatures for 2 hours The contact angle between water droplets and crude oil measured later remains above 150°, which proves that the surface has a stable structure, chemical composition and durability.

The invention successfully prepares an organic coating with superhydrophobic and superoleophobic properties by constructing a three-dimensional composite multilevel structure with fluorinated micro-nano silicon dioxide based on a sol-gel method and spraying or dipping. Due to the lack of substrate dependence, the coating can be coated on various soft and hard substrates by spraying or dipping and exhibits good superhydrophobic properties. Organic liquids with a surface energy as low as 28.7mN/m can also maintain a spherical shape on the surface coated with this layer and maintain a contact angle above 150°. When a dynamic droplet hits a flat surface at a certain speed, the droplet bounces on the surface in the form of a cake until the kinetic energy is exhausted. On an inclined surface, the droplet can also roll on the surface or leave in a bouncing manner with a rolling angle of less than 10° surface. In view of the excellent lyophobic properties and structural stability, the coated surface still exhibits good self-cleaning and anti-fouling functions even after being treated under harsh conditions such as high temperature, acid and alkali.

Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent replacements to the technical solution of the present invention by those skilled in the art will not depart from the present invention. The essence and scope of the technical solution of the invention.

Claims (7)

1. a kind of preparation method that is applicable to the super amphiphobic coating of various soft and hard substrates based on fluorinated silicon dioxide particle, is characterized in that, comprises the steps: A. Silica sol preparation: Mix nano-silica and micro-silica in a certain proportion, disperse them in a certain amount of ethanol solution and stir them magnetically for a period of time, then mix a certain amount of 3-aminopropyl triethyl Oxysilane is added to the mixed solution at room temperature and magnetically stirred for a period of time, and finally a certain amount of perfluorooctanoic acid and 1-ethyl-(3-dimethylaminopropyl) carbodiimide are respectively added to the mixed solution and heated at a certain temperature After reacting for a period of time, the particle sol can be obtained; B. Preparation of solid fluorinated particles: cooling the obtained sol to room temperature and centrifuging to separate solid particles, washing with ethanol twice to remove excess solvent and unreacted modifier, and drying at a certain temperature; C. Preparation of super amphiphobic coating: Dissolve a certain amount of polyvinylidene fluoride-hexafluoropropylene in a certain amount of N,N-dimethylformamide with magnetic stirring, and add a certain amount of n-octylamine to it, and add it to the solution Add a certain amount of fluorinated silicon dioxide particles, and stir magnetically for a period of time to obtain a light yellow mixed solution; D. Super-amphiphobic surface preparation: Soak the base material in a mixed solution of ethanol and acetone for a certain period of time and then dry it for later use. Add an appropriate amount of light yellow mixed solution into the spray gun and spray it on the hard substrate. Use dip coating The way to apply coatings on soft substrates. 2. a kind of preparation method that is applicable to the superamphiphobic coating of various soft and hard substrates based on fluorinated silicon dioxide particles as claimed in claim 1, it is characterized in that, in step A, raw material mass fraction ratio For: silicon dioxide: 3-aminopropyltriethoxysilane: perfluorooctanoic acid: 1-ethyl-(3-dimethylaminopropyl) carbodiimide 20:5:5:1, ethanol solution The ratio of the dosage to the silicon dioxide is 20ml:1g, and the silicon dioxide is selected from a combination of nanometer silicon dioxide and micrometer silicon dioxide in different proportions. 3. A kind of preparation method based on fluorinated silicon dioxide particles as claimed in claim 1 and 2 is applicable to the super amphiphobic coating of various soft and hard substrates, it is characterized in that, in step A, the selected nano The mass ratios of silicon dioxide and micron silicon dioxide are 4:0, 3:1, 2:2, and 1:3, respectively. 4. a kind of preparation method that is applicable to the super amphiphobic coating of various soft and hard substrates based on fluorinated silicon dioxide particles as claimed in claim 1 or 2, it is characterized in that, in step A, nanometer dioxide The particle sizes of silicon and micron silicon dioxide are 15-25nm and 0.5-1μm, respectively, and the magnetic stirring time of 3-aminopropyltriethoxysilane is 2-4h. Perfluorooctanoic acid and 1-ethyl-(3-dimethyl After aminopropyl) carbodiimide is added to the mixed solution, the reaction time is 6-10 hours, and the reaction temperature is 75-90°C. 5. a kind of preparation method that is applicable to the super amphiphobic coating of various soft and hard substrates based on fluorinated silicon dioxide particle as claimed in claim 1 or 2, is characterized in that, in step B and step D The drying temperature is 65°C. 6. a kind of preparation method based on fluorinated silicon dioxide particles as claimed in claim 1 or 2 is applicable to the super amphiphobic coating of various soft and hard substrates, it is characterized in that, in step C, polyvinylidene fluoride The mass fraction ratio of ethylene-hexafluoropropylene, N,N-dimethylformamide and n-octylamine is: 1:30:1. 7. a kind of preparation method of the super-amphiphobic coating that is applicable to various soft and hard substrates based on fluorinated silicon dioxide particles as claimed in claim 1 or 2, is characterized in that, described super-amphiphobic coating Suitable for a variety of soft and rigid substrate materials, including cloth, filter paper, PET flakes, sponges and glass.