CN105315801A - A preparation method of SiO2/polymer composite superhydrophobic coating - Google Patents

Abstract

The invention discloses a preparation method of a SiO2/polymer combined superhydrophobic coating. The preparation method comprises the following steps: adding a polymer into an organic solvent, and stirring till the polymer is dissolved completely to obtain a transparent solution I; adding hydrophobic nano silicon dioxide and a coupling agent, continuing stirring or carrying out ultrasonic dispersion till hydrophobic nano silicon dioxide is dispersed uniformly, adopting a pulling film forming method to obtain a uniform superhydrophobic coating, and drying the superhydrophobic coating at room temperature to obtain the product, wherein the addition proportion of the polymer to the organic solvent, hydrophobic nano silicon dioxide and the coupling agent is 1.6g:(40 to 50ml):(2.0 to 2.4g):1.0g. The preparation method has the advantages that the operation is simple; the raw materials are cheap and highly available; the repeatability is high; the prepared product has the advantages of both the polymer and inorganic nano particles, and is excellent in performance; each contact angle between the prepared product and water is 160 degrees or above; the roll angle of a water droplet on the surface of the coating is equal to or smaller than 10 degrees; a film made of the coating is uniform and suitable for various substrates.

Description

A preparation method of SiO2/polymer composite superhydrophobic coating

technical field

The invention belongs to the technical field of application of inorganic nanometer materials, and in particular relates to a preparation method of SiO ₂ /polymer composite super-hydrophobic coating.

Background technique

In recent years, due to the broad application prospects of superhydrophobic surfaces in real life, the preparation of superhydrophobic materials has become a research hotspot. Superhydrophobic surfaces have attractive prospects in many fields such as waterproof clothing, self-cleaning glass, exterior wall coatings, pipe microflow, waterproofing, anti-corrosion, oil-water separation, and biomedical applications. There are many methods for preparing superhydrophobic surfaces reported so far: etching method, sol-gel method, electrochemical method, phase separation method, electrospinning method, etc., but most of them require special equipment and specific experiments. Conditions or expensive fluorosilicon compounds can only be processed in small areas and are not suitable for large areas. Therefore, it is one of the problems to be solved to develop a superhydrophobic surface preparation method that is simple, feasible and convenient for application.

Contents of the invention

The purpose of the present invention is to overcome the defects of the prior art, and provide a preparation method of SiO ₂ /polymer composite super-hydrophobic coating, which is simple to operate, easy to control, uniform in film formation, and applicable to various substrates.

To achieve the above object, the present invention adopts the following technical solutions:

A preparation method of _SiO2 /polymer composite super-hydrophobic coating, which adds the polymer into the organic solvent, stirs at room temperature or heat until the polymer is completely dissolved to obtain a transparent solution; then adds hydrophobic nano silicon dioxide and coupling agent, continue to stir or ultrasonically disperse until the hydrophobic nano-silica is uniformly dispersed, obtain a uniform super-hydrophobic coating by pulling and forming a film, and dry it at room temperature; among them, polymers, organic solvents, and hydrophobic nano-silica The addition ratio of silica and coupling agent is 1.6g: 40-50ml: 2.0-2.4g: 1.0g. The contact angle between the obtained coating and water is above 160°, the rolling angle of water droplets on the coating surface is less than 10°, and the film is uniform and suitable for various substrates. The substrate can be glass, filter paper or fabric etc.

Specifically, the polymer is any one of polystyrene (PS), polyvinyl chloride (PVC), polyethylene (PE) and polymethyl methacrylate (PMMA).

The organic solvent is preferably tetrahydrofuran or toluene.

The particle size of the hydrophobic nano silicon dioxide is preferably 10-40nm.

The coupling agent is preferably γ-mercaptopropyltrimethoxysilane.

When pulling to form a film, the pulling speed is preferably 300-350 mm/min. When pulling to form a film, the substrate is immersed in a uniformly mixed solution, soaked for about 1min, and the pulling speed of the vertical pulling machine is adjusted at 300-350mm/min to obtain a uniform composite coating, and dried at room temperature to obtain a superhydrophobic coating. coating.

In the present invention, hydrophobic nano-silica is used as filler particles, which are uniformly dispersed and filled in the polymer under the condition of coupling agent, and a super-hydrophobic coating with different contact angles of more than 160° is obtained by using the method of pulling and forming a film. Coatings combine the advantages of polymers and nanoparticles. When the coating is dried at room temperature, during the phase separation process due to the volatilization of the organic solvent, the coupling agent connects the polymer and the hydrophobic nanoparticles and forms a higher chemical bond at the bonding interface, which greatly improves the adhesion between the nanoparticles and the polymerization. The bonding strength of the material improves the quality of the film.

Compared with prior art, the beneficial effect of the inventive method:

The invention uses hydrophobic nano silicon dioxide particles as a filler and adds them to polymers to form a functionalized nanocomposite material, which is a simple and effective method for preparing superhydrophobic coatings. The prepared polymer-based composite superhydrophobic material has both the advantages of polymer and inorganic nanoparticles, and has excellent performance. The contact angle with water is above 160°, and the rolling angle of water droplets on the coating surface is less than 10°. The film is uniform and suitable for on a variety of substrates. In addition, the preparation method of the present invention is simple in operation, cheap and easy to obtain raw materials, easy to control, good in repeatability and uniform in film formation, does not require modification of low surface energy substances and use of expensive equipment, and is easy for industrial production.

Description of drawings

Fig. 1 is the SEM photograph and the contact angle photograph of embodiment 1 SiO ₂ /PS composite superhydrophobic coating (substrate is glass slide);

Fig. 2 is the SEM photo and the contact angle photo of embodiment 2 SiO ₂ /PVC composite superhydrophobic coating (substrate is glass slide);

Fig. 3 is the SEM photo and the contact angle photo of embodiment 3 SiO ₂ /PMMA composite superhydrophobic coating (substrate is filter paper);

Fig. 4 is the contact angle photograph of embodiment 4 SiO ₂ /PE composite superhydrophobic coating (substrate is glass slide);

Fig. 5 is a photograph of the contact angle of the SiO ₂ /PS composite superhydrophobic coating (the substrate is fabric) in Example 5.

detailed description

The technical solutions of the present invention will be further described in detail below in conjunction with the examples, but the protection scope of the present invention is not limited thereto.

In the following examples, the hydrophobic nano-silica is DNS series nano-silica, which is organic-modified nano-silica, which has excellent hydrophobicity and lipophilicity, and ordinary commercially available products can be purchased. The DNS-2 nano-silica used in the examples was purchased from Henan Nanomaterials Engineering Technology Research Center.

Example 1

A preparation method of SiO ₂ /PS composite super-hydrophobic coating, specifically: adding 1.6g of polystyrene into 40ml of tetrahydrofuran, stirring magnetically until the polystyrene is completely dissolved to obtain a transparent solution. Then add 2.0 g of DNS-2 nano-silica, ultrasonicate for 0.5 h, then add 1.0 g of γ-mercaptopropyltrimethoxysilane, and continue stirring for 3 h until the nano-silica is uniformly dispersed. Take the glass slide as the substrate, adjust the pulling speed of the vertical pulling machine to 318mm/min, pull to form a film, and let it air at room temperature for 1 hour.

See Figure 1 for the SEM and contact angle photos of the obtained SiO ₂ /PS composite superhydrophobic coating, and the measured contact angle is 168.9±2°.

Example 2

A preparation method of SiO ₂ /PVC composite super-hydrophobic coating, specifically: adding 1.6g of polyvinyl chloride into 50ml of tetrahydrofuran, and magnetically stirring until the polyvinyl chloride is completely dissolved to obtain a transparent solution. Then add 2.4g of DNS-2 nano-silica, sonicate for 0.5h, then add 1.0g of γ-mercaptopropyltrimethoxysilane, and continue stirring for 3h until the nano-silica is evenly dispersed. Take the glass slide as the substrate, adjust the pulling speed of the vertical pulling machine to 318mm/min, pull to form a film, and let it air for 1 hour at room temperature.

See Figure 2 for the SEM and contact angle photos of the obtained SiO ₂ /PVC composite superhydrophobic coating, and the measured contact angle is 169.0±2°.

Example 3

A method for preparing a SiO ₂ /PMMA composite super-hydrophobic coating, specifically: adding 1.6 g of polymethyl methacrylate into 40 ml of tetrahydrofuran, and magnetically stirring until the polymethyl methacrylate is completely dissolved to obtain a transparent solution. Then add 2.0 g of DNS-2 nano-silica, sonicate for 0.5 h, then add 1.0 g of γ-mercaptopropyltrimethoxysilane, and continue stirring for 3 h until the silica is evenly dispersed. Use filter paper as the base, adjust the pulling speed of the vertical pulling machine to 318mm/min, pull to form a film, and let it air for 1 hour at room temperature.

See Figure 3 for the SEM and contact angle photos of the obtained SiO ₂ /PMMA composite superhydrophobic coating, and the measured contact angle is 167.6±2°.

Example 4

A preparation method of SiO ₂ /PE composite super-hydrophobic coating, specifically: adding 1.6g of polyethylene into 40ml of toluene, stirring magnetically at 90°C in a water bath until the polyethylene is completely dissolved, and obtaining a transparent solution. Then add 2.0 g of DNS-2 nano-silica, ultrasonicate for 0.5 h, then add 1.0 g of γ-mercaptopropyltrimethoxysilane, and continue stirring for 3 h until the silica is uniformly dispersed. Take the glass slide as the substrate, adjust the pulling speed of the vertical pulling machine to 318mm/min, pull to form a film, and let it air for 1 hour at room temperature.

The photo of the contact angle of the obtained SiO ₂ /PE composite superhydrophobic coating is shown in Fig. 4, and the measured contact angle is 162.3±2°.

Example 5

A preparation method of SiO ₂ /PS composite super-hydrophobic coating, specifically: adding 1.6g of polystyrene into 40ml of tetrahydrofuran, stirring magnetically until the polystyrene is completely dissolved to obtain a transparent solution. Then add 2.0 g of DNS-2 nano-silica, ultrasonicate for 0.5 h, then add 1.0 g of γ-mercaptopropyltrimethoxysilane, and continue stirring for 3 h until the nano-silica is uniformly dispersed. Take the fabric as the base, adjust the pulling speed of the vertical pulling machine to 318mm/min, pull to form a film, and let it air for 1 hour at room temperature.

See Figure 5 for the SEM and contact angle photos of the obtained SiO ₂ /PS composite superhydrophobic coating, and the measured contact angle is 168.9±2°.

Claims (6)

1. a kind of _SiO2 /polymer composite superhydrophobic coating preparation method, it is characterized in that, polymer is added in the organic solvent, is stirred until polymer dissolves completely and obtains transparent solution; Then add hydrophobic nano silicon dioxide and Coupling agent, continue to stir until the hydrophobic nano-silica is uniformly dispersed, obtain a uniform super-hydrophobic coating by pulling and forming a film, and dry it at room temperature; among them, the polymer, organic solvent, hydrophobic nano-silica The addition ratio of silicon oxide and coupling agent is 1.6g: 40-50ml: 2.0-2.4g: 1.0g. _2. SiO as claimed in claim 1 The preparation method of/polymer composite superhydrophobic coating is characterized in that, described polymer is polystyrene, polyvinyl chloride, polyethylene and polymethyl methacrylate any kind. 3. The preparation method of SiO ₂ /polymer composite superhydrophobic coating as claimed in claim 1, characterized in that, the organic solvent is tetrahydrofuran or toluene. 4 . The preparation method of SiO ₂ /polymer composite super-hydrophobic coating according to claim 1, characterized in that the particle size of the hydrophobic nano silicon dioxide is 10-40 nm. 5. The preparation method of SiO ₂ /polymer composite superhydrophobic coating as claimed in claim 1, characterized in that, the coupling agent is γ-mercaptopropyltrimethoxysilane. 6. The preparation method of SiO ₂ /polymer composite super-hydrophobic coating according to claim 1, characterized in that, when pulling to form a film, the pulling speed is 300-350mm/min.