CN115181337B

CN115181337B - Antibacterial hydrophobic membrane and preparation method thereof

Info

Publication number: CN115181337B
Application number: CN202210851256.8A
Authority: CN
Inventors: 王泽锋; 梁家铭; 展雪; 倪佳杰; 郭冬琴
Original assignee: Lishui University
Current assignee: Lishui University
Priority date: 2022-08-19
Filing date: 2022-08-19
Publication date: 2023-06-09
Anticipated expiration: 2042-08-19
Also published as: CN115181337A

Abstract

The invention discloses an antibacterial hydrophobic membrane and a preparation method thereof. The invention firstly prepares the eugenol derivative with mercapto and the pullulan derivative with double bonds, then grafts the eugenol derivative on the pullulan derivative through click reaction, and finally obtains the product. The reaction can be carried out under relatively mild conditions, the reaction speed is high, and the product has high selectivity. The prepared film material has remarkable antibacterial, hydrophobic, ultraviolet-resistant and corrosion-resistant properties. The prepared raw materials can be extracted from plants, are green and nontoxic, have high application value, and can be widely applied to the life fields of food packaging, medical facilities and the like.

Description

Antibacterial hydrophobic membrane and preparation method thereof

Technical Field

The invention relates to the technical field of functional films, in particular to an antibacterial hydrophobic film and a preparation method thereof.

Background

Bacteria still present a great threat to the physical health of humans, and the resulting impact is not insignificant. Mainly because bacteria are causative agents of many diseases, the diseases can be transmitted among normal human bodies through various modes, such as contact, alimentary canal, respiratory tract and the like, and the bacteria have strong infectivity. Meanwhile, with the development of technology, the application of novel materials such as semiconductors and sensors is more and more widespread, and the environment has great influence on the service performance of the materials, especially in a humid environment, carbonic acid generated by combining carbon dioxide in air with water has a corrosion effect on silicon wafers in the materials such as semiconductors and sensors. The film material with the antibacterial and hydrophobic functions can be widely applied, and is embodied in various fields of medical equipment coating, food packaging and the like. Therefore, the preparation of a coating having both antibacterial hydrophobicity and corrosion resistance is expected to be very promising in medical equipment and food packaging. Although the current synthetic materials have a certain antibacterial effect, most antibacterial films are prepared by taking toxic organic micromolecules, quaternary ammonium salts or nano silver as antibacterial materials, wherein the toxic organic micromolecules, the quaternary ammonium salts or the nano silver are extracted from fossil energy sources, the heat resistance is poor, the influence on the environment is caused in the production process, the latter is heavy metal, harsh reaction conditions are required, and the process is complicated. In addition, certain harm to human bodies can be caused in practical application, and the method is contrary to the concept of the development of the green environment-friendly industry advocated by the state of China, so that more superior raw materials need to be found, and the development of the green high-efficiency antibacterial coating is imperative.

The preparation of antimicrobial coating materials using natural raw materials is an effective strategy to solve the above problems. Some researchers report on the research of the relevant properties of synthetic antibacterial coatings using natural products as raw materials, including polysaccharides, cellulose derivatives, natural resins, and the like. Although all the coatings have antibacterial performance, the antibacterial performance cannot be exerted to the maximum, and the synthesis of the coatings is generally high in reaction temperature, adopts ultrasonic and ultraviolet means, is complicated in steps and has a certain potential safety hazard. Thus, a synthetic method of an antibacterial coating with mild reaction conditions is needed.

Among the raw materials, pullulan is the first choice, and its high gas resistance can show the inhibition of food surface bacteria breeding, effectively restrain and alleviate bacterial growth rate, and then the suppression food spoilage, extension food shelf life, simultaneously pullulan has good characteristics such as film-forming ability, cohesiveness and oxidation resistance, has been reported to carry out functional modification to pullulan, but the raw materials that use are poisonous organic micromolecule, will remain in the reaction process, and the polymer of preparation has certain adsorptivity, therefore the material of final preparation can have certain cytotoxicity.

Disclosure of Invention

The invention aims to provide an antibacterial hydrophobic membrane and a preparation method thereof. The problems of certain toxicity and poor film forming property in the existing synthetic antibacterial coating material are solved, meanwhile, the corrosion of carbon dioxide in the air to silicon wafers in materials such as semiconductors, sensors and the like can be effectively reduced, an antibacterial and corrosion-resistant film material is developed aiming at the series of problems, pullulan with good film forming property and natural antibacterial agent eugenol are selected as raw materials, and the two raw materials react with other raw materials to obtain the multifunctional film material. In order to solve the above-mentioned problems,

in order to solve the technical problems, the invention adopts the following technical scheme:

an antibacterial hydrophobic membrane, characterized in that the preparation method of the antibacterial hydrophobic membrane comprises the following steps:

(1) Preparation of pullulan derivatives: mixing pullulan and acryloyl chloride, dissolving in N, N-dimethylformamide, stirring at room temperature for 22-25h, and drying at 100-130 ℃ to obtain a pullulan derivative;

(2) Preparation of propyl 2-methoxy-4-thioacetate phenol (TAE): after eugenol is added into a three-neck flask filled with a magnet, the mixture is dropwise added under stirring of the magnetThioacetic acidIntroducing nitrogen when 1/2 of the total thioacetic acid is added, and adding Azobisisobutyronitrile (AIBN) under the condition of nitrogen; adding the rest 1/2 thioacetic acid, stirring at room temperature for 22-25h, stirring at 70-80 ℃ for 70-72 h, and performing rotary evaporation at 70-80 ℃ under vacuum degree of less than or equal to-98 KPa to obtain 2-methoxy-4-thioacetic acid propyl phenol (TAE);

(3) Preparation of 4- (3-mercaptopropyl) -2-methoxyphenol (TE): under the condition of nitrogen, adding the TAE prepared in the step (2) into the anaerobic methanol containing potassium hydroxide, heating the reaction mixture under reflux for 1-4h, and stirring at room temperature for 45-50h; acidifying the mixture with glacial acetic acid, extracting the organic phase with dichloromethane, adding water solution, performing rotary evaporation at 70-80 ℃ and vacuum degree of less than or equal to-98 KPa to obtain TE, and cooling to obtain brownish red viscous liquid, namely TE;

(4) Preparation of pullulan modification: taking the pullulan derivative obtained in the step (1), dropwise adding 1/2 of TE prepared in the step (3) under the stirring of a magnet, introducing nitrogen, adding AIBN under the nitrogen condition, dropwise adding the rest of TE prepared in the step (3), stirring at room temperature for 12-15 h, and stirring at 70-80 ℃ for 70-72 h to obtain a pullulan polysaccharide modified substance;

(5) Pouring the pullulan modified substance prepared in the step (4) on a substrate to obtain the antibacterial hydrophobic film.

Preferably, the mass ratio of the pullulan to the acryloyl chloride in the step (1) is 1:1.6 to 1:2.6, the ratio of the mass (g) of pullulan to the volume (mL) of N, N-dimethylformamide in step (1) is 1: 16-1: 24.

preferably, the eugenol of step (2): thioacetic acid: the mass ratio of the azodiisobutyronitrile is as follows: 24-28: 22-25: 0.001 to 0.005.

Preferably, the mass fraction of potassium hydroxide in the anaerobic methanol in the step (3) is 0.10-0.14 g/mL, and the mass ratio of the potassium hydroxide to the TAE is 13: 23-13:26, wherein the volume ratio of the anaerobic methanol to the glacial acetic acid is 10:3-4:1.

Preferably, the mass ratio of the pullulan derivative to TE to AIBN in the step (4) is 1:3.0 to 3.8:0.001 to 0.004.

Preferably, the substrate in step (5) may be a glass substrate, a polymer substrate, or a metal substrate.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the invention, the antibacterial hydrophobic membrane is synthesized by designing the chemical bonding of the modified pullulan polysaccharide and the modified eugenol, so that the problem that the antibacterial effect is not long-acting due to precipitation of the antibacterial agent caused by simple blending is avoided. The synthetic method is environment-friendly, the synthetic route does not damage the phenolic hydroxyl group of the bactericidal active group in eugenol, and a high-energy such as an ultraviolet lamp is not adopted in the preparation process, so that the damage of natural substances is avoided.

2. According to the invention, eugenol is introduced into the pullulan polysaccharide matrix, and the pullulan polysaccharide matrix molecules undergo an acylation reaction to generate covalent bonds so as to reduce hydrophilic hydroxyl groups, and the eugenol has hydrophobic groups so as to improve the hydrophobicity of the pullulan polysaccharide, improve the hydrophobicity and perform antibacterial action in cooperation with the antibacterial function of the eugenol. In addition, the improvement of hydrophobicity can effectively reduce corrosion of moisture to silicon chips, optical glass sodium silicate and the like in medical equipment, and eugenol can ionize H+ and inhibit dissolution of carbon dioxide, so that when the coating prepared by the invention is applied to the medical equipment, the corrosion of moisture and carbon dioxide in air to the equipment can be effectively reduced while the coating is antibacterial, and the service life of the equipment can be effectively prolonged. Meanwhile, the eugenol has aromatic rings, so that the thermal stability is improved, the application range of the antibacterial coating material is widened, the annular structure of the lulan polysaccharide is not damaged by a designed synthetic route, and the mechanical property is excellent.

3. The hydrophobic film prepared by the invention has good ultraviolet resistance and ultraviolet resistance, and the problem of physical property reduction caused by molecular weight reduction due to polymer chain segment breakage of pullulan polysaccharide caused by ultraviolet aging is avoided.

4. The hydrophobic membrane prepared by the application can be applied to the field of biology, and has the advantages of plant sources, no biotoxicity, enzyme degradation, weight reduction and environmental protection.

5. By adopting click chemistry, the reaction can be carried out under relatively mild conditions, the reaction speed is high, and the product has high selectivity. Most click chemistry reactions currently require ultraviolet radiation, which can lead to polymer breakage, affecting product efficiency. The method of the invention is different from other conditions required by click chemistry, and AIBN is used as a catalyst to react at a proper temperature to obtain a product.

Drawings

FIG. 1 is an infrared spectrum of example 1 and comparative example 1, wherein a dotted line is an infrared spectrum of comparative example 1, and a solid line is an infrared spectrum of example 1;

FIG. 2 is a graph of ultraviolet transmittance of example 1 and comparative example 1, wherein the dotted line is the infrared spectrum of comparative example 1, and the solid line is the infrared spectrum of example 1;

FIG. 3 is a graph showing the antibacterial effect of example 1 and comparative example 1;

FIG. 4 is a graph showing the hydrophilicity and hydrophobicity test of the pure pullulan film containing blue dye of example 1, wherein A, B, C is a graph showing 3 stages before immersing in water, immersing in water for 10min and taking out, and D, E, F is a graph showing 3 stages before immersing in water, immersing in water for 10min and taking out, respectively, of example 1;

FIG. 5 is a graph of the enzymatic degradation of example 1 and comparative example 1, wherein the broken line is the enzymatic degradation curve of comparative example 1, and the solid line is the enzymatic degradation curve of example 1;

fig. 6 is a graph of thermal weight loss of example 1 and comparative example 1, wherein the broken line is a thermal weight loss curve of comparative example 1, and the solid line is a thermal weight loss curve of example 1.

Detailed Description

The present invention is described in detail by the following examples, which are only for further explanation of the present invention and are not to be construed as limiting the scope of the present invention. It is to be understood that various changes and modifications may be made by one skilled in the art after reading the disclosure herein, and that such equivalents are intended to fall within the scope of the claims appended hereto.

Example 1:

the preparation method of the antibacterial hydrophobic membrane comprises the following steps:

(1) Preparation of pullulan derivatives: mixing 0.5g of pullulan with 0.8112g of acryloyl chloride, dissolving in 10mLN, N-dimethylformamide, stirring at room temperature for 24 hours, and drying at 120 ℃ to obtain a pullulan derivative;

(2) Preparation of propyl 2-methoxy-4-thioacetate phenol: after 26.7g of eugenol is added into a three-neck flask filled with a magnet, 12.15g of thioacetic acid is firstly added dropwise under the stirring of the magnet, nitrogen is introduced, and 3mg of azobisisobutyronitrile is added under the condition of nitrogen; then 12.15g of thioacetic acid is added dropwise, stirred for 24 hours at room temperature, then stirred for 72 hours at 75 ℃, and then subjected to rotary evaporation at 75 ℃ and vacuum degree of less than or equal to-98 KPa to obtain 2-methoxy-4-propyl thioacetate phenol;

(3) Synthesis of 4- (3-mercaptopropyl) -2-methoxyphenol (TE): 5.2g of potassium hydroxide was dissolved in 45mL of oxygen-free methanol, 10g of TAE prepared in step (2) was added under nitrogen, heated under reflux for 2 hours, and stirred at room temperature for 48 hours. Acidifying the mixture with 12mL glacial acetic acid, extracting the organic phase with dichloromethane, adding water solution, steaming at 75deg.C under vacuum degree of less than or equal to-98 KPa, and cooling to obtain brownish red viscous liquid TE;

(4) Preparation of pullulan modification: taking 1.1145g of the pullulan derivative prepared in the step (1), dropwise adding 1.7745gTE g of nitrogen under the stirring of a magnet, adding 3mg of AIBN under the nitrogen condition, dropwise adding 1.7745g of TE into the system, stirring at room temperature for 12h, and stirring at 75 ℃ for 72h to obtain a pullulan polysaccharide modified substance;

(5) Pouring the pullulan modified substance prepared in the step (4) on a substrate to obtain an antibacterial hydrophobic film; cytotoxicity test was performed on the obtained antibacterial hydrophobic membrane, and the result shows that the prepared antibacterial hydrophobic membrane is the same as pullulan (absorbance (1)).

Example 2:

(1) Preparation of pullulan derivatives: mixing 0.5g of pullulan with 1.2168g of acryloyl chloride, dissolving in 8mL of N, N-dimethylformamide, stirring at room temperature for 22h, and drying at 100 ℃ to obtain a pullulan derivative;

(2) Preparation of propyl 2-methoxy-4-thioacetate phenol (TAE): after 24.5g of eugenol is added into a three-neck flask filled with a magnet, 11.05g of thioacetic acid is firstly added dropwise under the stirring of the magnet, nitrogen is introduced, and 5mg of azobisisobutyronitrile is added under the condition of nitrogen; then 11.05g of thioacetic acid is added dropwise, stirred for 24 hours at room temperature, then stirred for 72 hours at 80 ℃, and then subjected to rotary evaporation at 70 ℃ and vacuum degree of less than or equal to-98 KPa to obtain 2-methoxy-4-propyl thioacetate phenol;

(3) Synthesis of 4- (3-mercaptopropyl) -2-methoxyphenol (TE): 5.2g of potassium hydroxide was dissolved in 50mL of oxygen-free methanol, 9.5g of TAE prepared in step (2) was added under nitrogen, heated under reflux for 1h, and stirred at room temperature for 45h. Acidifying the mixture with 12.5mL glacial acetic acid, extracting the organic phase with dichloromethane, adding water solution, performing rotary evaporation at 70 ℃ under vacuum degree of less than or equal to-98 KPa, and cooling to obtain brownish red viscous liquid TE;

(4) Preparation of pullulan modification: taking 1.4593g of the pullulan derivative prepared in the step (1), dropwise adding 2.662gTE g of nitrogen under the stirring of a magnet, adding 2mg of AIBN under the nitrogen condition, dropwise adding 2.662gTE into the system, stirring at room temperature for 13h, and stirring at 80 ℃ for 72h to obtain a pullulan polysaccharide modified substance;

(5) Pouring the pullulan modified substance prepared in the step (4) onto a substrate to obtain an antibacterial hydrophobic film; cytotoxicity test was performed on the obtained antibacterial hydrophobic membrane, and the result shows that the prepared antibacterial hydrophobic membrane is the same as pullulan (absorbance (1)).

Example 3:

(1) Preparation of pullulan derivatives: mixing 0.5g of pullulan with 1.014g of acryloyl chloride, dissolving in 12mL of N, N-dimethylformamide, stirring at room temperature for 25h, and drying at 130 ℃ to obtain a pullulan derivative;

(2) Preparation of propyl 2-methoxy-4-thioacetate phenol: after 27.8g of eugenol is added into a three-neck flask filled with a magnet, 12.45g of thioacetic acid is firstly added dropwise under the stirring of the magnet, nitrogen is introduced, and 1mg of azobisisobutyronitrile is added under the condition of nitrogen; then 12.45g of thioacetic acid is added dropwise, stirred for 24 hours at room temperature, then stirred for 72 hours at 70 ℃, and then subjected to rotary evaporation at 80 ℃ and vacuum degree of less than or equal to-98 KPa to obtain 2-methoxy-4-propyl thioacetate phenol;

(3) Synthesis of 4- (3-mercaptopropyl) -2-methoxyphenol (TE): 5.2g of potassium hydroxide was dissolved in 40mL of oxygen-free methanol, 10g of TAE prepared in step (2) was added under nitrogen, heated under reflux for 4 hours, and stirred at room temperature for 50 hours. Acidifying the mixture with 12mL glacial acetic acid, extracting the organic phase with dichloromethane, adding water solution, steaming at 80deg.C under vacuum degree of less than or equal to-98 KPa, and cooling to obtain brownish red viscous liquid TE;

(4) Preparation of pullulan modification: taking 1.2869g of the pullulan derivative prepared in the step (1), dropwise adding 2.2188gTE g of nitrogen under the stirring of a magnet, adding 4mg of AIBN under the nitrogen condition, dropwise adding 2.2188g of TE into the system, stirring at room temperature for 15h, and stirring at 70 ℃ for 72h to obtain a pullulan polysaccharide modified substance;

Comparative example 1:

and pouring the pullulan on a substrate to obtain the membrane.

Experimental method

Examples 1 to 3 and comparative examples were tested, wherein the infrared and ultraviolet light transmittance, antibacterial, hydrophilic and hydrophobic properties, enzymatic degradation, cytotoxicity and thermogravimetric analysis test methods were as follows:

fourier transform infrared spectroscopy studies were performed on example 1 using FTIR-1500 fourier transform infrared spectrometer. The spectrum is 400-4000cm ^-1 In the wave number range of 4cm ^-1 Is scanned 4 times.

The ultraviolet transmittance is measured by using an ultraviolet spectrophotometer UV-2600 (Shimadzu corporation) and scanning the transmission spectrum of the coating in the wavelength range of 200-800 nm, and the ultraviolet blocking performance and the transparency are evaluated by measuring the transmittance.

The antibacterial test procedure is the reference: international Journal of Polymer Science Volume 2018,Article ID 5659137,9pages https:// doi.org/10.1155/2018/5659137.

Test of hydrophilic and hydrophobic Properties: the pullulan and the popular acrylic pigment (429 sky blue) produced by the company of the American bang prayer, guangzhou, are uniformly mixed and dissolved in deionized water (blue can better observe whether the pullulan is dissolved), the obtained blue pullulan aqueous solution and the antibacterial hydrophobic film prepared in the example 1 are respectively and uniformly coated on a glass slide, the glass slide is dried, and then the glass slide and the glass slide are placed in water for a period of time, and then the dissolution degree of the film on the glass slide is observed.

Enzymatic degradation: 2 dialysis bags were prepared, one filled with the modified pullulan prepared in example 1, one filled with pullulan, each having a mass of about 0.1g, and about 4mg of alpha-amylase was added to each dialysis bag. The 4 dialysis bags were placed in PBS solution at pH 7.4, the PBS solution outside the bags was changed every three days, oven dried (60 ℃ C.) before each PBS solution change, and weighed. Degradation mass = dialysis bag mass + sample mass + enzyme mass-total weight after drying.

The cytotoxicity test procedure is described in the reference https:// doi.org/10.1016/S1875-5372 (11) 60017-9, antibacterial Adhesion of Borneol-Based Polymer via Surface Chiral Stereochemistry, https:// pubs.acs.org/journ/aaick.

The thermal stability of example 1 was tested using a TA instrument Q50 in the united states. About 10mg of each film was taken in a standard aluminum pan and heated from room temperature to 700℃at a heating rate of 20℃per minute under a nitrogen flow of 50cm 3/min.

The test results are shown in the accompanying drawings 1-6, table 1 and table 2. As can be seen from FIG. 1, the modified pullulan prepared in example 1 was found to be 1233cm in length ^-1 The peak of (C) corresponds to the C-S bond, indicating that thioacetic acid is chemically incorporated into the product by clicking and 1705cm ^-1 The peak at this point represents the formation of carbonyl groups, which are introduced by the acryloyl chloride, 3296cm ^-1 Hydroxyl stretching vibration representing intra-molecular/inter-molecular hydrogen bond of pullulan and 2930cm ^-1 Is the characteristic peak of methoxy group of pullulan, 1608,1509cm ^-1 The stretching vibration of the eugenol benzene ring can be obtained, so that the antibacterial hydrophobic film is generated between the reactants through bonding. The antibacterial hydrophobic membrane is successfully synthesized. As can be seen from fig. 2, the pullulan film prepared in comparative example 1 has good light transmittance, almost 100% of light transmittance in the ultraviolet wavelength range of 280-400nm, i.e. no blocking property to ultraviolet, while the modified pullulan film, i.e. example 1, has almost 0 of light transmittance in the ultraviolet wavelength range of 280-300nm, and less than 10% of light transmittance in the 300-400nm, thus having good ultraviolet blocking property, because the aromatic ring in eugenol improves ultraviolet absorption capacity, thereby enhancing n→pi x conversion in the ultraviolet range. As can be seen from FIG. 3, the unmodified pullulan in comparative example 1 has more flora, the agar plate of the antibacterial hydrophobic membrane prepared after modification has basically no or few flora, and the coating has better inhibition effect on staphylococcus aureus; as can be seen from fig. 4, the blue dye-containing pullulan coating had a complete film on the glass slide before being placed in water, and the glass slide was taken out after being placed in water for ten minutes, indicating that the blue dye-containing pullulan coating had almost disappeared, indicating that the pullulan was extremely hydrophilic and had good solubility in water, whereas the complete film remained on the glass slide after being placed in water for ten minutes in example 1, and therefore, the hydrophobicity of the pullulan was greatly improved after the pullulan was modified in the present invention. As can be seen from fig. 5, pullulan has excellent enzymatic degradability, and has been completely enzymatically degraded around the third day; the greatest problem is that the modified substance loses degradability and is difficult to be degraded by enzyme after the pullulan is modified, but the modified pullulan prepared in example 1The blue polysaccharide still has good enzymatic degradability, and the enzymatic degradation rate reaches about 50% in the sixth day. As can be seen from fig. 6, the initial 5% mass loss temperature and 50% mass loss temperature of pullulan are 150 ℃ and 350 ℃, respectively, the initial 5% mass loss temperature and 50% mass loss temperature of example 1 are 100 ℃ and 350 ℃, respectively, the weight of pullulan and example 1 is reduced in the temperature range of 300-360 ℃, and the thermal stability of example 1 is better than that of pullulan, at 700 ℃, pullulan is almost completely lost, and the weight residue of example 1 is almost 50%, and the thermal stability is improved.

The Zeta potential of the pullulan and eugenol modified pullulan aqueous solution is tested by using a Zeta potentiometer, the concentration of the aqueous solution is 1mg/mL, and the operation conditions are as follows: 11.4V/cm,13.0MA,25 ℃. As a result, the aqueous pullulan solution had a zeta potential value of 1.9.+ -. 0.2mV, and after the aqueous pullulan solution was modified with eugenol, the zeta potential value was reduced to 1.3.+ -. 0.2mV. This is due to ionization of eugenol to H in aqueous solution ⁺ At the same time H ⁺ The ionization of the modified substance enhances the acidity, thereby being unfavorable for the entry of carbon dioxide and effectively reducing the corrosion of carbon dioxide in the air to silicon chips and the like.

TABLE 1 Zeta potential values for comparative example 1 and example 1

	Comparative example 1 aqueous pullulan solution	Aqueous solution of pullulan modification prepared in example 1
			Zeta potential value (mV)	1.9±0.2	1.3±0.2

And (3) cutting n-type Czochralski (CZ) by using a Varian-Cary5000 ultraviolet-visible light-near infrared spectrophotometer with an integrating sphere, and testing the reflectivity of the monocrystalline silicon wafer with the resistivity of 1-3 omega cm by using the crystal orientation (100). And respectively comparing the reflectivities of the silicon wafers in three different environments: the silicon wafer of the control group is placed in a vacuum environment (the silicon wafer is not corroded by moisture and carbon dioxide in air); experimental group 1 silicon wafer coated with the antibacterial hydrophobic film of example 1; experiment group 2 is a pure silicon wafer. The reflectivity of the test groups 1 and 2 was tested after being placed in the natural indoor environment of the Liwater institute for 90 days, and the change degree of the reflectivity was compared with that of the silicon wafer placed in the vacuum environment. Wherein the step of washing off the coated antibacterial hydrophobic film of experimental group 1 is: sequentially soaking the antibacterial hydrophobic membrane in four different solvents of ethanol, acetone, tetrahydrofuran and deionized water for 30min, and washing the antibacterial hydrophobic membrane clean, wherein the washing step is repeated for more than three times respectively to completely remove the antibacterial hydrophobic membrane. The following tables show the degree of reduction of the reflectivity of the experimental groups 1 and 2 compared with the control group, and it can be seen from the following tables that after the silicon wafer is placed in the natural environment, the reflectivity of the silicon wafer is reduced due to corrosion by carbon dioxide in the air, and the degree of reduction of the reflectivity of the silicon wafer coated with the antibacterial hydrophobic film prepared by the invention is lower than that of the silicon wafer not coated with the antibacterial hydrophobic film because the film can effectively reduce corrosion of carbon dioxide.

Table 2 reflectance values for comparative example 1 and example 1

	Silicon wafer coated with film of example 1 (film washed off at the time of test)	Pure silicon wafer without coating the film of example 1
			Reflectance drop value	3％	12％

The above is only a specific embodiment of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions or modifications made on the basis of the present invention to solve the substantially same technical problems and achieve the substantially same technical effects are encompassed within the scope of the present invention.

Claims

1. An antibacterial hydrophobic membrane, characterized in that the preparation method of the antibacterial hydrophobic membrane comprises the following steps:

(2) Preparation of propyl 2-methoxy-4-thioacetate phenol (TAE): adding eugenol into a three-neck flask with a magnet, dropwise adding thioacetic acid under the stirring of the magnet, introducing nitrogen when 1/2 of the total thioacetic acid is added, and adding Azobisisobutyronitrile (AIBN) under the condition of nitrogen; adding the rest 1/2 thioacetic acid, stirring at room temperature for 22-25h, stirring at 70-80 ℃ for 70-72 h, and performing rotary evaporation at 70-80 ℃ under vacuum degree of less than or equal to-98 KPa to obtain 2-methoxy-4-thioacetic acid propyl phenol (TAE);

(3) Preparation of 4- (3-mercaptopropyl) -2-methoxyphenol (TE): under the condition of nitrogen, adding the TAE prepared in the step (2) into the anaerobic methanol containing potassium hydroxide, heating the reaction mixture in a reflux way for 1-4h, and stirring at room temperature for 45-50h; acidifying the mixture with glacial acetic acid, extracting the organic phase with dichloromethane, adding water solution, performing rotary evaporation at 70-80 ℃ and vacuum degree of less than or equal to-98 KPa to obtain TE, and cooling to obtain brownish red viscous liquid, namely TE;

2. An antimicrobial hydrophobic film according to claim 1, wherein the mass ratio of pullulan to acryloyl chloride in step (1) is 1:1.6 to 1:2.6, the ratio of the mass (g) of the pullulan to the volume (mL) of the N, N-dimethylformamide in the step (1) is 1:16-1:24.

3. An antimicrobial hydrophobic film according to claim 1, wherein the eugenol of step (2): thioacetic acid: the mass ratio of the azodiisobutyronitrile is 24-28: 22-25: 0.001 to 0.005.

4. An antimicrobial hydrophobic film according to claim 1, wherein the mass fraction of potassium hydroxide in the anaerobic methanol in step (3) is 0.10-0.14 g/mL, and the mass ratio of potassium hydroxide to TAE is 13:23 to 13:26, wherein the volume ratio of the anaerobic methanol to the glacial acetic acid is 10: 3-4: 1.

5. an antimicrobial hydrophobic film according to claim 1, wherein the mass ratio of pullulan derivative to TE to AIBN of step (4) is 1:3.0 to 3.8:0.001 to 0.004.

6. An antimicrobial hydrophobic film according to claim 1, wherein the substrate of step (5) is selected from the group consisting of a glass substrate, a polymeric substrate, and a metal substrate.