CN105088538B - A kind of preparation method of hydrophobin coating - Google Patents

Abstract

The invention is applicable to the technical field of amphoteric polymer materials, and provides a method for preparing a hydrophobic/superhydrophobic protein coating. The method comprises the following steps: weighing zein and dissolving it in an alcohol-water solution to form zein After the solution is mixed, the solubility of the zein solution is 50-400mg/ml; the zein solution is placed in the syringe of the electrospinning equipment to prepare a hydrophobic/superhydrophobic protein coating . The method has simple preparation process and low preparation cost; and the preparation speed is improved, and can be applied to large-scale production.

Description

A kind of preparation method of hydrophobin coating

technical field

The invention belongs to the technical field of amphoteric polymer materials, and in particular relates to a method for preparing a hydrophobin coating.

Background technique

Hydrophobic materials refer to materials with surface water contact angles greater than 90°, while superhydrophobic materials refer to materials with surface water contact angles greater than 150°. Hydrophobic/superhydrophobic surfaces are generally prepared by two methods: increasing surface roughness and reducing surface energy. The enhancement of surface roughness at the nano- and micro-scale can be obtained by various methods such as photolithography, chemical etching, templating, sol-gel synthesis, controlled crystallization, phase separation, electrospinning, graft polymerization, layer- layer method, deposition and colloidal self-assembly, etc. The acquisition of low surface energy often requires surface chemical coating assistance or surface molecular modification. At present, hydrophobic/superhydrophobic materials use fluorine-containing coatings to reduce surface energy. This material is not only expensive and toxic, but also bioaccumulates in the environment and causes environmental pollution. Molecular modification involves multi-step chemical reactions, which is time-consuming and labor-intensive, and does not meet the requirements of low energy consumption and environmental protection. Superhydrophobic materials have been synthesized on various organic and inorganic material substrates, including polymer materials, silicon wafers, glass sheets, and metal sheets. However, the resulting substrates are not ideal, and they suffer from poor mechanical flexibility, transparency and tensile strength.

Electrospinning is a technology that uses a polymer solution or melt to form a jet flow under a strong electric field for spinning. In recent years, electrospinning has attracted more and more attention due to its ultra-fine fiber processing technology. At present, there are as many as 30 kinds of polymers that can be processed by electrospinning in the world, including natural polymers such as DNA, collagen, and silk protein, as well as polyoxyethylene, polyacrylonitrile, nylon, polyvinyl alcohol, polyurethane, and polycaprolactone. Synthetic polymers such as esters. This method saves a lot of money and energy compared to expensive, time-consuming and polluting methods. At present, due to the lack of guarantee of advanced electrospinning equipment, the efficiency of electrospinning industrial production is extremely low, and the use of electrospinning technology to achieve high-speed production of fiber coatings requires extremely high requirements for production equipment.

Contents of the invention

The purpose of the present invention is to provide a method for preparing a hydrophobic/superhydrophobic protein coating that is environmentally friendly, low in cost, and high in production efficiency, aiming to solve the problem of high equipment requirements and production problems in the production of hydrophobic/superhydrophobic protein coatings in the prior art. Low efficiency and poor mechanical properties of resulting hydrophobic/superhydrophobic protein coatings.

The present invention is achieved like this, a kind of preparation method of hydrophobic/superhydrophobic protein coating, comprises the following steps:

Weighing zein and dissolving it in an alcohol-water solution to form a zein solution and then performing mixing treatment, the solubility of the zein solution is 50-400 mg/ml;

The zein solution was placed in a syringe of an electrospinning device to prepare a hydrophobic/superhydrophobic protein coating.

The preparation method of the hydrophobic/superhydrophobic protein coating provided by the present invention uses the amphoteric protein zein as a raw material and adopts electrospinning technology to prepare the hydrophobic/superhydrophobic protein coating. First, the method does not require surface coating and molecular modification, so the preparation process is simple and the preparation cost is low; secondly, the zein used is non-toxic, biodegradable and biocompatible, has the prospect of sustainable development, and the obtained hydrophobic/superhydrophobic The protein coating has good mechanical flexibility; again, the electrospinning technology is used to prepare the hydrophobic/superhydrophobic protein coating, and the preparation speed is improved, which reduces the dependence on equipment and can be applied to large-scale production.

Description of drawings

Fig. 1 is the water contact angle and the SEM image of the hydrophobic coating prepared by the 50mg/ml zein solution when the spinning voltage provided by the embodiment of the present invention is 18kV;

Fig. 2 is the water contact angle and the SEM image of the superhydrophobic coating prepared by the 100mg/ml zein solution when the spinning voltage provided by the embodiment of the present invention is 18kV;

Fig. 3 is the water contact angle and the SEM image of the superhydrophobic coating prepared by the 150mg/ml zein solution when the spinning voltage provided by the embodiment of the present invention is 18kV;

Fig. 4 is the water contact angle and the SEM image of the hydrophobic coating prepared by the 200mg/ml zein solution when the spinning voltage provided by the embodiment of the present invention is 18kV;

Fig. 5 is the water contact angle and SEM image of the hydrophobic coating prepared by the 250mg/ml zein solution when the spinning voltage provided by the embodiment of the present invention is 18kV;

Fig. 6 is the water contact angle and SEM image of the hydrophobic coating prepared from the 300mg/ml zein solution when the spinning voltage provided by the embodiment of the present invention is 18kV;

Fig. 7 is the water contact angle and SEM image of the hydrophobic coating prepared from the 100mg/ml zein solution when the spinning voltage provided by the embodiment of the present invention is 10kV;

Fig. 8 is the water contact angle and SEM image of the hydrophobic coating prepared from the 100mg/ml zein solution when the spinning voltage provided by the embodiment of the present invention is 12kV;

Fig. 9 is the water contact angle and SEM image of the hydrophobic coating prepared from the 100mg/ml zein solution when the spinning voltage provided by the embodiment of the present invention is 21kV;

Fig. 10 is the SEM image of the hydrophobic coating prepared from the 300 mg/ml zein solution provided by the embodiment of the present invention when the spinning voltage is 18 kV;

Fig. 11 is the hydrophobic coating and the SEM image prepared by the zein solution provided in Comparative Example 1;

Fig. 12 is the hydrophobic coating and SEM image prepared from the zein solution provided in Comparative Example 2.

detailed description

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Whether in fundamental research or in industry, superhydrophobic surfaces (SHS) have attracted increasing attention due to their potential applications as self-cleaning surfaces, such as solar cells, automobile windshields, and traffic lights. The SHS surface is also capable of anti-fouling, anti-biofouling, anti-stick and water-repellent properties. Despite numerous successful biomimetic studies to achieve superhydrophobic surfaces, only a few have addressed their potential biomaterial applications. In view of this, the embodiment of the present invention provides a method for preparing a hydrophobic/superhydrophobic protein coating, comprising the following steps:

S01. Weighing zein and dissolving it in an alcohol-water solution to form a zein solution and then performing mixing treatment, the solubility of the zein solution is 50-400 mg/ml;

S02. The zein solution is placed in a syringe of an electrospinning device to prepare a hydrophobic/superhydrophobic protein coating.

Specifically, in the above step S01, the zein is a main protein in corn, and is a biomacromolecule with good mechanical properties. It is abundant, inexpensive, biocompatible, and a renewable resource. Meanwhile, the zein is a natural amphoteric protein having both hydrophilic and hydrophobic groups. The inventors found that due to the special self-assembled structural characteristics of zein, the hydrophobic/superhydrophobic protein coating formed by using it has good hydrophobic properties. There is currently no technology for making hydrophobic or superhydrophobic films from zein. In the embodiment of the present invention, a hydrophobic or superhydrophobic protein film is produced for the first time using zein as a material through a simple processing method, which will be a promising alternative to the traditional method for preparing superhydrophobic.

In the embodiment of the present invention, ethanol-water solution is selected as the alcohol-water solution. Ethanol is a non-toxic solvent with good volatility and has no harm to the environment. Using ethanol as a solubilizer component is beneficial to the following electrospinning technology and helps hydrophobic/superhydrophobic proteins to produce silk. Therefore, for electrospinning Low equipment requirements result in uniform hydrophobic/superhydrophobic coatings. As a preferred embodiment, the alcohol-water solution is an ethanol-water solution with a volume percentage of 30-95% ethanol. As a further preferred embodiment, the alcohol-water solution is an ethanol-water solution with a volume percentage of 80-90% ethanol. Especially when the volume percentage of ethanol-ethanol in water is 80% to dissolve zein, it is more helpful for silk production.

A zein solution is obtained by dissolving the above zein, and the concentration of the zein solution is 50-400 mg/ml. This reasonable concentration range effectively guarantees the hydrophobicity and fibrillation characteristics of the hydrophobic/superhydrophobic protein film. As a preferred embodiment, the concentration of the zein solution is 100-300 mg/ml.

Thoroughly mix the prepared above-mentioned zein solution until the solution is uniform and transparent. As a preferred embodiment, the mixing treatment method of the zein solution is to subject the zein solution to ultrasonic treatment, and the ultrasonic time is 8-15 minutes, and the ultrasonic time is more preferably 10 minutes. Of course, it should be understood that other methods in the art that can fully mix the zein solution are also within the protection scope of the embodiments of the present invention.

In order to ensure that zein does not denature, the treatment of the above step S01 is preferably carried out at normal temperature and pressure.

In the above step S02, electrospinning is used to prepare the hydrophobic/superhydrophobic protein coating. In order to achieve industrial production and at the same time ensure the fiber-forming properties of the final product, the requirements for classical and unrestrained machinery and equipment are extremely high. The inventors of the present application have repeatedly studied and innovated the method for preparing hydrophobic/superhydrophobic protein coatings by electrospinning, and found that using zein as a raw material, and as long as the relevant parameters of the electrospinning equipment are well controlled, only need to use General electrospinning equipment can achieve the purpose of high-speed production of hydrophobic/superhydrophobic protein coating, the speed can be increased to 20ml/h, and the hydrophobic/superhydrophobic protein has a good silk-out effect during the preparation process, and the obtained hydrophobic/superhydrophobic protein The hydrophobin coating is uniformly fibrous under the electron microscope SEM, and the fiber diameter is 0.7-1.2 microns.

In order to achieve the above effects, it is a preferred embodiment. In the step of preparing a hydrophobic/superhydrophobic protein coating by electrospinning, the electrospinning voltage is 10-30kV, the electrospinning speed is 0.5-20ml/h, and the spinning needle of the electrospinning equipment reaches The distance between the receiving plates is 10-30cm. As a further preferred embodiment, the voltage of the electrospinning is 10-21kV, the propulsion speed of the spinning liquid is 0.5-10ml/h, and the distance from the spinning needle to the receiving plate is 25cm. By setting the above parameters, the zein was solidified into a film on the receiving electrospinning device.

In the embodiment of the present invention, natural polymers are used to replace synthetic compounds. First, the by-product zein of corn wet processing is used to quickly and efficiently prepare hydrophobic/superhydrophobic coatings. On the one hand, zein is low in cost and non-toxic , biodegradable, good biocompatibility, green and environmental protection, effectively protect the environment and improve sustainable development; on the other hand, using amphiphilic zein as raw material avoids molecular modification and low surface energy coating On the premise of ensuring quality, the production process is saved. At the same time, due to the special amphiphilic molecular structure and self-assembly characteristics of zein, it can be grown rapidly and mass-produced by using general electrospinning machines. Fiber coating, thus greatly saving industrial production costs. Secondly, electrospinning is used to replace the existing method of preparing superhydrophobic materials, making the production method from complex to simple, with simple steps, low equipment requirements, and high controllability, which can be applied to large-scale industrial production. And the preparation speed can reach 20ml/h, which effectively improves the production efficiency. In addition, the hydrophobic/superhydrophobic coating prepared by the method of the embodiment of the present invention has good hydrophobic performance, its water contact angle can reach up to 153°, and it has a self-cleaning function.

The following will be described in conjunction with specific embodiments.

Example 1

Under normal temperature and pressure (15-35°C, 1 standard atmospheric pressure), weigh 0.5g of zein, dissolve it in 10ml of 80% (v/v) ethanol-water, make a 50mg/ml solution, and ultrasonicate for 10min until the solution is homogeneous and transparent. The configured solution was injected into the syringe of the electrospinning equipment, the spinning voltage was set to 18kV, the propulsion speed of the spinning solution was 0.2ml/h, and the distance from the spinning needle to the receiving plate was 25cm. Films were prepared by electrospinning equipment. The prepared zein hydrophobic coating has a water contact angle of 138.2°, and its water contact angle and SEM electron micrograph are shown in Fig. 1 .

Example 2

Under normal temperature and pressure (15-35°C, 1 standard atmospheric pressure), weigh 1.0g of zein, dissolve it in 10ml of 80% (v/v) ethanol-water, make a 100mg/ml solution, and ultrasonicate for 10min until the solution is homogeneous and transparent. The configured solution was injected into the syringe of the electrospinning equipment, the spinning voltage was set to 18kV, the propulsion speed of the spinning solution was 0.2ml/h, and the distance from the spinning needle to the receiving plate was 25cm. Films were prepared by electrospinning equipment. The prepared zein superhydrophobic coating has a water contact angle of 153.6°, and its water contact angle and SEM electron micrograph are shown in Figure 2.

Example 3

Under normal temperature and pressure (15-35°C, 1 standard atmospheric pressure), weigh 1.5g of zein, dissolve it in 10ml of 80% (v/v) ethanol-water, make a 150mg/ml solution, and ultrasonicate for 10min until the solution is homogeneous and transparent. The configured solution was injected into the syringe of the electrospinning equipment, the spinning voltage was set to 18kV, the propulsion speed of the spinning solution was 0.2ml/h, and the distance from the spinning needle to the receiving plate was 25cm. Films were prepared by electrospinning equipment. The prepared zein superhydrophobic coating has a water contact angle of 150.4°, and its water contact angle and SEM electron micrograph are shown in Figure 3.

Example 4

Under normal temperature and pressure (15-35°C, 1 standard atmospheric pressure), weigh 2.0g of zein, dissolve it in 10ml of 80% (v/v) ethanol-water, make a 200mg/ml solution, and sonicate for 10min until the solution is homogeneous and transparent. The configured solution was injected into the syringe of the electrospinning equipment, the spinning voltage was set to 18kV, the propulsion speed of the spinning solution was 0.2ml/h, and the distance from the spinning needle to the receiving plate was 25cm. Films were prepared by electrospinning equipment. The prepared zein hydrophobic coating has a water contact angle of 143.8°, and its water contact angle and SEM electron micrograph are shown in Figure 4.

Example 5

Under normal temperature and pressure (15-35°C, 1 standard atmospheric pressure), weigh 2.5g of zein, dissolve it in 10ml of 80% (v/v) ethanol-water, make a 250mg/ml solution, and sonicate for 10min until the solution is homogeneous and transparent. The configured solution was injected into the syringe of the electrospinning equipment, the spinning voltage was set to 18kV, the propulsion speed of the spinning solution was 0.2ml/h, and the distance from the spinning needle to the receiving plate was 25cm. Films were prepared by electrospinning equipment. The prepared zein hydrophobic coating has a water contact angle of 141.0°, and its water contact angle and SEM electron micrograph are shown in Fig. 5 .

Example 6

Under normal temperature and pressure (15-35°C, 1 standard atmospheric pressure), weigh 3.0g of zein, dissolve it in 10ml of 80% (v/v) ethanol-water, make a 300mg/ml solution, and sonicate for 10min until the solution is homogeneous and transparent. The configured solution was injected into the syringe of the electrospinning equipment, the spinning voltage was set to 18kV, the propulsion speed of the spinning solution was 0.2ml/h, and the distance from the spinning needle to the receiving plate was 25cm. Films were prepared by electrospinning equipment. The prepared zein hydrophobic coating has a water contact angle of 136.4°, and its water contact angle and SEM electron micrograph are shown in Fig. 6 .

Example 7

Under normal temperature and pressure (15-35°C, 1 standard atmospheric pressure), weigh 1.0g of zein, dissolve it in 10ml of 80% (v/v) ethanol-water, make a 100mg/ml solution, and ultrasonicate for 10min until the solution is homogeneous and transparent. The configured solution was injected into the syringe of the electrospinning equipment, the spinning voltage was set to 10kV, the propulsion speed of the spinning solution was 0.2ml/h, and the distance from the spinning needle to the receiving plate was 25cm. Films were prepared by electrospinning equipment. The prepared zein hydrophobic coating has a water contact angle of 130.5°, and its water contact angle and SEM electron micrograph are shown in Fig. 7 .

Example 8

Under normal temperature and pressure (15-35°C, 1 standard atmospheric pressure), weigh 1.0g of zein, dissolve it in 10ml of 80% (v/v) ethanol-water, make a 100mg/ml solution, and ultrasonicate for 10min , until the solution is homogeneous and transparent. The configured solution was injected into the syringe of the electrospinning equipment, the spinning voltage was set to 12kV, the propulsion speed of the spinning solution was 0.2ml/h, and the distance from the spinning needle to the receiving plate was 25cm. Films were prepared by electrospinning equipment. The prepared zein hydrophobic coating has a water contact angle of 131.2°, and its water contact angle and SEM electron micrograph are shown in Fig. 8 .

Example 9

Under normal temperature and pressure (15-35°C, 1 standard atmospheric pressure), weigh 1.0g of zein, dissolve it in 10ml of 80% (v/v) ethanol-water, make a 100mg/ml solution, and ultrasonicate for 10min until the solution is homogeneous and transparent. The configured solution was injected into the syringe of the electrospinning equipment, the spinning voltage was set to 21kV, the propulsion speed of the spinning solution was 0.2ml/h, and the distance from the spinning needle to the receiving plate was 25cm. Films were prepared by electrospinning equipment. The prepared zein hydrophobic coating has a water contact angle of 139.4°, and its water contact angle and SEM electron micrograph are shown in Fig. 9 .

Example 10

Under normal temperature and pressure (15-35°C, 1 standard atmospheric pressure), weigh 3.0g of zein, dissolve it in 10ml of 80% (v/v) ethanol-water, make a 300mg/ml solution, and sonicate for 10min until the solution is homogeneous and transparent. The configured solution was injected into the syringe of the electrospinning equipment, the spinning voltage was set to 18kV, the propulsion speed of the spinning solution was 10ml/h, and the distance from the spinning needle to the receiving plate was 25cm. Films were prepared by electrospinning equipment. The prepared zein hydrophobic coating fiber was well formed, and the water contact angle was 124.2°, and its SEM electron micrograph was shown in Figure 10 .

Comparative example 1

Zein has film-forming properties. When the concentration of zein is 300mg/ml, the water contact angle of the film obtained under natural drying is 73°, and the surface of the film is smooth. The SEM electron micrograph of the film is shown in Figure 11. picture.

Comparative example 2

With the help of self-aligned monolayer (SAM), through the process of evaporation-induced self-assembly (EISA), zein can be made into a hydrophobic film with a water contact angle of 115°, and its SEM electron micrograph is shown in Figure 12 As shown in the picture.

Through the comparison of the water contact angle, it can be seen that the electrospinning technology greatly improves the hydrophobicity of the zein film. Scanning electron microscope images of different membranes show that the fibers obtained by electrospinning have good uniformity, small pore size and high porosity. Using the method described in Comparative Example 2 to prepare a hydrophobic membrane requires cumbersome operations, and only a low-concentration zein solution can be used, resulting in poor mechanical properties of the membrane.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (4)

1. a kind of preparation method of hydrophobin coating, it is characterised in that comprise the steps of：

Under 15-35 DEG C, 1 standard atmosphere condition, weigh zeins and be dissolved in alcohol-water solution, it is molten to form corn alcohol Mixing processing is carried out after protein solution, the solubility of the zein solution is 50~400mg/ml, and the corn alcohol is molten Zein solution is is ultrasonically treated by the mixing processing method of protein solution, ultrasonic time 10min；

The zein solution is placed in the syringe of electrospinning device hydrophobin coating is prepared, in institute State in the step of electrostatic spinning prepares hydrophobin coating, the voltage of the electrostatic spinning is 21kV, and electrostatic spinning speed is 0.2ml/h, the distance of spinning syringe needle to the receiver board of electrospinning device are 25cm, the fibre diameter of the hydrophobin coating For 0.7-1.2 microns, the contact angle of the hydrophobin coating is 139.4 °.

2. the preparation method of hydrophobin coating as claimed in claim 1, it is characterised in that the alcohol-water solution be ethanol- The aqueous solution.

3. the preparation method of hydrophobin coating as claimed in claim 1, it is characterised in that the alcohol-water solution is ethanol Percent by volume be 30~95% ethanol-water solution.

4. the preparation method of the hydrophobin coating as described in claims 1 to 3 is any, it is characterised in that the alcohol-water solution The ethanol-water solution that percent by volume for ethanol is 80~90%.