阅读说明：本技术 一种超浸润涂层的制备方法 (Preparation method of super-wetting coating ) 是由 刘帅 李岫锦 张悦 刘德启 马玲 徐梦佳 徐佳雯 杨肖静 彭雪 于 2021-07-08 设计创作，主要内容包括：本发明提供了一种超浸润涂层的制备方法,包括以下步骤：将预涂有疏水试剂的基材置于等离子体聚合反应器的放电区内,然后将放电区密封,接通电源进行等离子处理,得到超浸润涂层。本发明中的方法具有无需特别前处理、聚合反应器小巧且调整方便、无需特殊工作气体、常温常压、反应迅速、试剂消耗极小、能耗低、无“三废”排放的技术特点；制备的疏水涂层具有疏水性好、涂层均匀、结合力牢、耐侯性好等良好品质；这是一种具有极大市场应用潜力的疏水涂层及含疏水区域超浸润涂层的制备技术。(The invention provides a preparation method of a super-wetting coating, which comprises the following steps: and placing the base material precoated with the hydrophobic reagent in a discharge area of a plasma polymerization reactor, sealing the discharge area, and switching on a power supply to perform plasma treatment to obtain the super-wetting coating. The method has the technical characteristics of no need of special pretreatment, small and exquisite polymerization reactor, convenient adjustment, no need of special working gas, normal temperature and pressure, rapid reaction, little reagent consumption, low energy consumption and no three-waste discharge; the prepared hydrophobic coating has good quality such as good hydrophobicity, uniform coating, firm binding force, good weather resistance and the like; the preparation method is a preparation technology of the hydrophobic coating with great market application potential and the super-wetting coating containing the hydrophobic area.)

1. A preparation method of a super-wetting coating comprises the following steps:

placing the base material precoated with the hydrophobic reagent in a discharge area of a dielectric barrier discharge plasma reactor, sealing the discharge area, switching on a power supply, and carrying out low-temperature plasma-induced in-situ polymerization treatment at normal pressure to obtain the super-wetting coating.

2. The method of claim 1, wherein the working gas for the low temperature plasma-induced in situ polymerization process is air in a confined discharge region of limited volume.

3. The method of claim 1, wherein the discharge region is sealed from the outside air using a rubber packing.

4. The method of claim 1, wherein the substrate pre-coated with the hydrophobic agent is prepared by the steps of:

and (3) uniformly coating the hydrophobic reagent on the surface of the base material to obtain the base material precoated with the hydrophobic reagent.

5. The method according to claim 1, wherein the hydrophobic agent is a compound containing a long-chain hydrocarbon or a perfluoro-chain hydrocarbon.

6. The method of claim 1, wherein the height of the arrester region is 1 to 2 times the thickness of the substrate, and the arrester region has an area 1.1 to 1.5 times the area of the substrate.

7. The production method according to claim 1, wherein the base material is a flat material having a thickness of 4mm or less;

the flat material is natural polymer, synthetic polymer, inorganic nonmetal or metal film, sheet, textile material or non-woven material.

8. The preparation method according to any one of claims 1 to 7, wherein the hydrophobic reagent further comprises 1 to 3g/L of inorganic nanoparticles.

9. The method of claim 8, wherein the inorganic nanoparticles are nano-silicon particles;

the particle size of the inorganic nanoparticles is 30-50 nm.

Technical Field

The invention belongs to the technical field of functional materials, and particularly relates to a preparation method of a super-wetting coating.

Background

The super-wetting material comprises super-hydrophilic and super-hydrophobic materials, wherein the super-hydrophilic material is a material which has a contact angle of a liquid drop with the surface of the super-hydrophilic and super-hydrophobic materials close to 0 degree, water can be rapidly dispersed on the surface to form a completely wetted surface, and the super-hydrophobic material has a contact angle of more than 150 degrees, and the water drop cannot slide and spread on the surface to keep a spherical rolling shape. With the rise of bionics, people find that water drops have different adhesion behaviors on different natural hydrophobic surfaces from nature. For example, the contact angle between water and the lotus leaf surface is very large and the adhesion force is very low, so that water drops are easy to adhere and dirt is easy to fall off from the lotus leaf surface, and the self-cleaning effect is achieved. The lotus leaf surface is covered with 10 μm high papilla which is randomly distributed, each papilla is provided with a hydrophobic waxy crystal with the height of about 100nm, and the surface micro-nano coarse structure has stronger capability of holding semi-stable state air retention, thereby forming an air layer for lifting water drops, enabling the water drops not to enter a nano gap, and enabling the lotus leaf surface to show super-hydrophobic low water adhesion. As another example, the Nanbrazzeria includes a back rest that collects water vapor from the surrounding atmosphere from the projections on the back to sustain survival. It has been found that the rugged surface of the beetle comprises alternating wax-coated hydrophobic and non-waxy hydrophilic areas, water vapour condenses on the beetle, and the raised surface contains a number of hydrophilic areas of about 100 μm in size as nucleation sites for the condensation of water vapour. When the condensed droplets reach a critical size, the droplets are transported in a waxy hydrophobic region and storage occurs as the critical droplets are transported along the waxy hydrophobic region to its mouth.

Inspired by biological super-wetting surfaces in nature, people adopt methods such as etching, electrochemistry, thermal cracking, chemical deposition, phase separation, a template method, sol-gel, chemical modification, self-assembly, electrostatic spinning and the like to bionically construct the super-wetting surfaces, and functional materials applied to the fields of anti-fouling, self-cleaning, flow resistance reduction, ice coating prevention, mist collection and the like are developed, and the materials can be used for automobile windshields, cable snow-proof and anti-freezing protective layers, airplane wing laminar flow air flow resisting protective layers, anti-fouling self-cleaning textiles, water vapor collecting materials and the like. However, the method has the problems of complex pretreatment, long reaction time, high reagent consumption, generation of a large amount of wastewater, high energy consumption and the like.

The low-temperature plasma induced polymerization technology is widely applied to the preparation of the wetting surface due to the advantages of low energy consumption, controllability, clean and pollution-free reaction process and the like, and the wetting coating is prepared by in-situ polymerization on the surface of a base material through induced polymerization monomer molecules such as high-energy electrons generated in the discharge process, active groups with strong oxidizing property and the like to generate polymerization grafting on the surface of the base material. For the preparation of hydrophobic coatings by plasma treatment, the conventional method is to initiate the polymerization grafting of hydrophobic molecules (long chain hydrocarbons, fluorinated alkanes, etc.) on the surface of the substrate by Plasma Enhanced Chemical Vapor Deposition (PECVD), or to pre-decorate hydrophobic reagents on the surface of the sample and place the sample in a vacuum chamber to receive plasma treatment. During the process of preparing hydrophobic coating by plasma, fluorine-containing gas (CF)₄Etc.) or inert gas (argon, etc.) is generally used as the working gas of the reaction, and the treatment process needs to be finished in a vacuum chamber, the preparation process is more complicated, and the continuous production is difficult to realize; if the preparation is carried out under normal pressure, protective gas is introduced to isolate air, so as to prevent nitrogen and oxygen in the air from being ionized in a high-voltage electric field to form active groups containing nitrogen and oxygen, so that the surface of a substrate is hydrophilized or the hydrophobicity of a coating is greatly reduced. In addition, the production cost of the method is high.

Disclosure of Invention

The invention aims to provide a preparation method of a super-wetting coating.

The invention provides a preparation method of a super-wetting coating, which comprises the following steps:

placing the base material precoated with the hydrophobic reagent in a discharge area of a dielectric barrier discharge plasma reactor, sealing the discharge area, switching on a power supply, and carrying out low-temperature plasma-induced in-situ polymerization treatment at normal pressure to obtain the super-wetting coating.

Preferably, the working gas for the low-temperature plasma-induced in-situ polymerization treatment is air in a limited-volume closed discharge area.

Preferably, the discharge area is sealed from the outside air by using a rubber sealing ring.

Preferably, the substrate precoated with the hydrophobic agent is prepared according to the following steps:

and (3) uniformly coating the hydrophobic reagent on the surface of the base material to obtain the base material precoated with the hydrophobic reagent.

Preferably, the hydrophobic agent is a long chain hydrocarbon siloxane and/or a fluorinated siloxane.

Preferably, the height of the discharge area is 1-2 times of the thickness of the base material, and the area of the discharge area is 1.1-1.5 times of the area of the base material.

Preferably, the base material is a flat material having a thickness of 4mm or less;

the flat material is natural polymer, synthetic polymer, inorganic nonmetal or metal film, sheet, textile material or non-woven material.

Preferably, the hydrophobic reagent further comprises 1-3 g/L of inorganic nanoparticles.

Preferably, the inorganic nanoparticles are nano-silicon particles;

the particle size of the inorganic nanoparticles is 30-50 nm.

The invention provides a preparation method of a super-wetting coating, which comprises the following steps: and placing the base material precoated with the hydrophobic reagent in a discharge area of a dielectric barrier discharge plasma polymerization reactor, sealing the discharge area, and switching on a power supply to perform low-temperature plasma-induced in-situ polymerization treatment to obtain the super-wetting coating. The method has the technical characteristics of no need of special pretreatment, small and exquisite polymerization reactor, convenient adjustment, no need of special working gas, normal temperature and pressure, rapid reaction, little reagent consumption, low energy consumption and no three-waste discharge; the prepared hydrophobic coating has good quality such as good hydrophobicity, uniform coating, firm binding force, good weather resistance and the like; the preparation method is a preparation technology of the hydrophobic coating with great market application potential and the super-wetting coating containing the hydrophobic area.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic diagram of a plasma polymerization reactor used in preparing a super-wetting coating in accordance with an embodiment of the present invention;

wherein, 1 is a plasma power supply, 2 is a rubber sealing ring, 3 is a dielectric flat plate, 4 is a positive plate, and 5 is a negative plate.

Detailed Description

The invention provides a preparation method of a super-wetting coating, which comprises the following steps:

and placing the base material precoated with the hydrophobic reagent in a discharge area of the dielectric barrier discharge plasma reactor, sealing the discharge area, and switching on a power supply to perform low-temperature plasma-induced in-situ polymerization treatment to obtain the super-wetting coating.

Referring to fig. 1, the positive and negative plates and the sealing rubber ring form a sealed discharge region in which a limited amount of air is present, and it is this limited amount of air that is used as a working gas in the present invention that generates plasma at a suitable operating voltage to induce the polymerization grafting of monomer molecules containing hydrophobic groups onto the substrate surface.

Preferably, the hydrophobic reagent is prepared into a hydrophobic solution, and then the hydrophobic solution is coated on the surface of the substrate and dried to obtain the substrate pre-coated with the hydrophobic reagent.

In the present invention, the hydrophobic agent is preferably a long-chain hydrocarbon-or perfluoro-chain hydrocarbon-containing compound such as a long-chain hydrocarbon siloxane and/or a fluorinated siloxane, specifically, hexadecyltrimethoxysilane, perfluorooctyltrimethoxysilane; the solvent in the hydrophobic reagent solution is preferably an organic solvent, such as ethanol, acetone, and the like; the concentration of the hydrophobic reagent solution is preferably 0.01-1 mol/L, more preferably 0.03-0.8 mol/L, and most preferably 0.1-0.5 mol/L.

In the invention, in order to further improve the hydrophobic performance, inorganic nanoparticles are added into the hydrophobic reagent, and the inorganic nanoparticles are preferably nano silicon particles; Si-O-Si can be formed between the silicon particles and silane to complete the hydrophobic modification of the silicon particles; the mass concentration of the inorganic nanoparticles in the hydrophobic reagent solution is preferably 1-3 g/L, more preferably 1.2-2.5 g/L, and most preferably 1.2-2 g/L; the particle size of the inorganic nanoparticles is preferably 30-50 nm.

The method of coating is not particularly limited in the present invention, and an appropriate coating method such as spray coating, dip coating, spin coating, etc. may be employed depending on the type of the substrate.

In the present invention, the drying is preferably natural airing/drying.

And placing the base material precoated with the hydrophobic reagent into a discharge area, sealing by using a sealing rubber ring, then switching on a power supply, and carrying out plasma treatment under normal pressure to obtain the super-wetting coating.

In the invention, the area of the discharge area can enable the sample to be horizontally spread, the area is slightly larger than the volume of the sample, and preferably, the area of the discharge area is 1.1-1.5 times of the area of the base material. The height of the discharge area is preferably 1-2 times of the thickness of the base material.

In the present invention, the voltage and the processing time of the plasma processing may be specifically selected according to the material, the size, the discharge distance, and the physicochemical properties of the substrate, and specifically, in the embodiment of the present invention, may be 30 to 40V; the treatment time is preferably 5-10 min.

In the present invention, the temperature of the plasma treatment is preferably normal temperature.

The invention provides a preparation method of a super-wetting coating, which comprises the following steps: and placing the base material precoated with the hydrophobic reagent in a discharge area of a dielectric barrier discharge plasma polymerization reactor, sealing the discharge area, and switching on a power supply to perform low-temperature plasma-induced in-situ polymerization treatment to obtain the super-wetting coating. The method has the technical characteristics of no need of special pretreatment, small and exquisite polymerization reactor, convenient adjustment, no need of special working gas, normal temperature and pressure, rapid reaction, little reagent consumption, low energy consumption and no three-waste discharge; the prepared hydrophobic coating has good quality such as good hydrophobicity, uniform coating, firm binding force, good weather resistance and the like; the preparation method is a preparation technology of the hydrophobic coating with great market application potential and the super-wetting coating containing the hydrophobic area.

In order to further illustrate the present invention, the following examples are provided to describe the preparation method of a super-wetting coating of the present invention in detail, but should not be construed as limiting the scope of the present invention.

Example 1

The modified sample is a cotton fabric, and is cut into a shape of 3cm × 3 cm. The hydrophobic agent is hexadecyl trimethoxy silane. In the treatment process, in order to ensure good siloxane polymerization and simultaneously not to cause strong etching of the fabric by plasma caused by too strong discharge, the working voltage of the plasma treatment is set to be 30V, and the treatment time is 5 minutes. The fabric sample is firstly put into 0.1M siloxane ethanol solution for dip-coating for 1 minute and then naturally dried, and then the pre-coated sample is put into a discharge area of a plasma reactor for plasma treatment.

Table 1 shows the contact and roll angles of the fabric samples at different plasma treatment doses. As can be seen from the data in the table, the untreated cotton fabric is hydrophilic; the hydrophobicity of the sample is gradually increased along with the increase of the treatment dosage; however, when the treatment voltage exceeds 30V, the hydrophobicity of the sample is reduced. Obviously, the optimum operating voltage is 30V. In addition, when the sealing ring is removed and other processing conditions are not changed, the sample is treated to be super-hydrophilic, which is mainly caused by that a large amount of polar groups are grafted in the sample during the processing process.

In addition, in the pre-coating decoration link, all experimental conditions are the same (including the types of hydrophobic reagents, the concentration of solution and the like), the pre-coated decoration cotton fabric is subjected to plasma treatment by using sub-atmospheric pressure glow discharge plasma, the working gas is argon, the discharge power is 150W, the treatment time is 3 minutes, and the chamber pressure is maintained at 60pa during discharge. It can be seen from the data in the table that under the same pre-decoration condition, the hydrophobicity of the sample after being replaced by the argon plasma treatment is not much different from that after being treated by the plasma mentioned in the application, but the sub-atmospheric pressure glow discharge plasma treatment has higher requirements on the vacuum degree and the working gas, and the treatment energy consumption is higher.

TABLE 1 hydrophobicity of cotton fabric samples at different treatment voltages (treatment duration 5min)

Example 2

The cotton fabric was pre-coated, but 1.2g/L of nano-silicon particles (particle size 30 to 50nm) were mixed into the original pre-coating agent, and then plasma treatment was performed at the same dose as in example 1 (Table 2). It can be seen from the table that the hydrophobicity of the sample is further improved after the nanoparticles are added. Therefore, the preparation method provided by the invention is convenient and feasible, and the coating is firmer.

After ultrasonic treatment in water for 10min, the hydrophobicity of the sample is not changed obviously, which shows that the coating prepared by the method of the invention has excellent adhesive force even without pretreatment (Table 3).

TABLE 2 hydrophobicity of cotton fabric samples after addition of Nano-silicon particles (treatment duration 5min)

TABLE 3 Cotton Fabric sample hydrophobicity before and after sonication (treatment duration 5min)

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.