Cellulose acetate nanofiber membrane, method of making and use thereof

Abstract

The application discloses cellulose acetate nanofiber membrane and a preparation method and application thereof, and the preparation method comprises the following steps: mixing cellulose acetate and N,N-dimethylacetamide, heating to 50-60 DEG C under stirring and stirring at the temperature for 6-8 h to obtain a first mixed solution, adding urushiol into the first mixed solution to obtain a second mixed solution, heating to 70-80 DEG C under stirring and stirring at the temperature for 4-6 h to obtain a third mixed solution, cooling to room temperature, adding anhydrous copper sulfate into the third mixed solution under stirring, continuing to stir for 4-6 h to obtain a spinning solution, and performing electrostatic spinning on the spinning solution to obtain the cellulose acetate nanofiber membrane. The cellulose acetate nanofiber membrane has high acid resistance, prevents clothes covered with the cellulose acetate nanofiber membrane from being corroded and damaged by acidic agents during use, has good killing effect on escherichia coli and staphylococcus aureus, and also has good killing effect on influenza A virus.

Description

Technical Field

[0001] This invention belongs to the field of polymer nanofiber materials technology, specifically relating to a cellulose acetate nanofiber membrane, its preparation method, and its application. Background Technology

[0002] Cellulose acetate is a readily available man-made fiber with low cost and excellent weaving properties. Due to its strong thermal stability, high flow rate, and low adsorption, cellulose acetate membranes are widely used in many industries, including textiles, clinical medicine, and product packaging. However, its poor acid resistance is a major drawback in its application.

[0003] Urushiol is a component extracted from raw lacquer. It is a series of catechol derivatives with different saturated side chains. Urushiol coatings have excellent properties such as waterproofing, corrosion resistance, and antimicrobial activity. However, the nano-scale formation of urushiol is currently very difficult. Therefore, finding a method for nano-scale formation of urushiol is of great importance.

[0004] Meanwhile, with the pandemic and public health security becoming increasingly severe, the requirements for the antibacterial and antiviral effects of epidemic prevention materials such as masks and medical protective clothing are becoming increasingly stringent. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a method for preparing cellulose acetate nanofiber membranes. This method utilizes urushiol to modify cellulose acetate and dops it with copper ions to create an acid-resistant spinning solution with copper ion antibacterial and anti-H3N2 virus properties. The cellulose acetate nanofiber membrane is then prepared by electrospinning, which has broad application scenarios in the medical and epidemic prevention materials or clothing coating markets.

[0006] Another object of the present invention is to provide a cellulose acetate nanofiber membrane obtained by the above preparation method.

[0007] Another object of the present invention is to provide the application of the above-mentioned cellulose acetate nanofiber membrane in the preparation of antimicrobial clothing coatings.

[0008] The objective of this invention is achieved through the following technical solution.

[0009] A method for preparing a cellulose acetate nanofiber membrane includes the following steps:

[0010] 1) Cellulose acetate and N,N-dimethylacetamide are mixed and heated to 50-60°C under stirring, and stirred at this temperature for 6-8 hours to obtain a first mixture. Urushiol is added to the first mixture at a flow rate of 0.1-0.15 g / h. When the mass ratio of urushiol to cellulose acetate is 1:(4-5), the addition of urushiol is stopped to obtain a second mixture, wherein the cellulose acetate is 12-15 wt% of N,N-dimethylacetamide.

[0011] In step 1), the heating rate to 50-60°C is 10-12°C / hour.

[0012] In step 1), the method for preparing the urushiol is as follows: raw lacquer and anhydrous ethanol are mixed, ultrasonicated, impurities are filtered, and rotary evaporated at 180~182℃ until all the anhydrous ethanol is evaporated to obtain urushiol. The ratio of raw lacquer to anhydrous ethanol by volume is 1:(3~4).

[0013] In the above technical solution, the ultrasound duration is 1~1.5h.

[0014] 2) Under stirring conditions, the second mixture is heated to 70~80℃ and stirred at this temperature for 4~6h to obtain the third mixture. After cooling to room temperature, anhydrous copper sulfate is added to the third mixture at a flow rate of 0.05~0.08 g / h under stirring conditions. When the mass ratio of the anhydrous copper sulfate to the urushiol is 1:(4~5), the addition of anhydrous copper sulfate is stopped, and stirring is continued for 4~6h to obtain the spinning solution.

[0015] In step 2), the heating rate to 70-80°C is 10-12°C / hour.

[0016] 3) Electrospin the spinning solution to obtain a cellulose acetate nanofiber membrane.

[0017] In step 3), the electrospinning voltage is 26~28kV.

[0018] In step 3), the electrospinning syringe has an 18G needle, the injection speed of the syringe is 1~1.2ml / hr, and the distance between the receiving device and the syringe is 15~20cm.

[0019] In the above technical solution, the stirring speed is 600~700 rpm.

[0020] The cellulose acetate nanofiber membrane obtained by the above preparation method.

[0021] The above-mentioned cellulose acetate nanofiber membrane is used in the preparation of antimicrobial clothing coatings.

[0022] The beneficial effects of this invention are as follows:

[0023] (1) The cellulose acetate nanofiber membrane of the present invention has high acid resistance, preventing clothing covered with it from being corroded and damaged by acidic agents during use.

[0024] (2) Based on the traditional applications of cellulose acetate membranes, the addition of urushiol, a natural material, in this invention enables cellulose acetate nanofilms to exhibit high acid resistance. The urushiol in this invention is currently the only natural material capable of making cellulose acetate nanofiber membranes resistant to 98% sulfuric acid corrosion, rather than a synthetic additive improving cellulose acetate. Compared to synthetic additives, urushiol significantly enhances the acid resistance of cellulose acetate membranes, and the process is environmentally friendly and simple.

[0025] (3) The cellulose acetate nanofiber membrane of the present invention has a good elimination effect on Escherichia coli and Staphylococcus aureus, and also has a good inactivation effect on influenza A virus (H3N2). Attached Figure Description

[0026] Figure 1 (a) SEM and (b) wire diameter of cellulose acetate nanofiber membrane;

[0027] Figure 2 These are images showing the antibacterial effects after 24 hours of cultivation in Examples 3-6.

[0028] Figure 3 The image shows the cellulose acetate nanofiber membrane obtained in Example 1 after being immersed in a sulfuric acid aqueous solution for 1 hour, wherein the concentration of the sulfuric acid aqueous solution is (a) 60 wt%, (b) 80 wt%, and (c) 98 wt%.

[0029] Figure 4 Photograph of concentrated sulfuric acid dropped onto the surface of the cellulose acetate nanofiber membrane obtained in Example 1 after 30 minutes;

[0030] Figure 5 Photographs of the blank cellulose acetate nanofiber membrane (a) prepared in Comparative Example 1 and the cellulose acetate nanofiber membrane (b) prepared in Example 1 after 24 hours of contact with H3N2 virus suspension.

[0031] Figure 6 The image shows the cellulose acetate nanofiber membrane obtained in Example 4 after being immersed in a sulfuric acid aqueous solution for 1 hour, wherein the concentration of the sulfuric acid aqueous solution is (a) 60 wt%, (b) 80 wt%, and (c) 98 wt%.

[0032] Figure 7 Photograph of concentrated sulfuric acid dropped onto the surface of the cellulose acetate nanofiber membrane obtained in Example 4 after 30 minutes;

[0033] Figure 8 The image shows the cellulose acetate nanofiber membrane obtained in Example 5 after being immersed in a sulfuric acid aqueous solution for 1 hour, wherein the concentration of the sulfuric acid aqueous solution is (a) 60 wt%, (b) 80 wt%, and (c) 98 wt%.

[0034] Figure 9 Photograph of concentrated sulfuric acid dropped onto the surface of the cellulose acetate nanofiber membrane obtained in Example 5 after 30 minutes;

[0035] Figure 10 The image shows the cellulose acetate nanofiber membrane obtained in Example 6 after being immersed in a sulfuric acid aqueous solution for 1 hour, wherein the concentration of the sulfuric acid aqueous solution is (a) 60 wt%, (b) 80 wt%, and (c) 98 wt%.

[0036] Figure 11 This is a photograph taken 30 minutes after concentrated sulfuric acid was dropped onto the surface of the cellulose acetate nanofiber membrane obtained in Example 6. Detailed Implementation

[0037] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0038] The raw materials used in the following examples were purchased from the following sources: anhydrous ethanol (≥99.5%), purchased from Sinopharm Chemical Reagent Co., Ltd.; N,N-dimethylacetamide (AR), purchased from Sinopharm Chemical Reagent Co., Ltd.; cellulose acetate (acetyl 39.8 wt%, hydroxyl 3.5 wt%, M=40,000), purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; anhydrous copper sulfate (≥99.99%), purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; raw lacquer, purchased from Fuzhou Dongchang Raw Lacquer Co., Ltd.; and Escherichia coli and Staphylococcus aureus strains, purchased from the China Microbial Culture Collection Center.

[0039] Example 1

[0040] A method for preparing a cellulose acetate nanofiber membrane includes the following steps:

[0041] 1) Cellulose acetate and N,N-dimethylacetamide were mixed and heated to 60°C at a rate of 10°C / hour under magnetic stirring at 700 rpm, and stirred at this temperature for 6 hours (heated in a water bath) to obtain a first mixture. Urushiol was added to the first mixture at a flow rate of 0.1 g / h. When the mass ratio of urushiol to cellulose acetate was 1:5, the addition of urushiol was stopped to obtain a second mixture, wherein the cellulose acetate was 15 wt% of N,N-dimethylacetamide. The method for preparing urushiol was as follows: raw lacquer and anhydrous ethanol were mixed, sonicated for 1 hour, impurities were filtered, and rotary evaporated at 180°C until all the anhydrous ethanol was evaporated to obtain urushiol. The volume ratio of raw lacquer to anhydrous ethanol was 1:3.

[0042] 2) Under magnetic stirring at 700 rpm, the second mixture is heated to 80°C at a rate of 10°C / hour and stirred at this temperature for 4 hours to obtain the third mixture. The mixture is then cooled to room temperature (20~25°C). Anhydrous copper sulfate is added to the third mixture at a flow rate of 0.05 g / h under stirring at 700 rpm. When the mass ratio of anhydrous copper sulfate to urushiol is 1:4, the addition of anhydrous copper sulfate is stopped, and stirring is continued for 4 hours to obtain the spinning solution.

[0043] 3) The spinning solution was electrospun to obtain cellulose acetate nanofiber membrane. The electrospinning voltage was 27kV, the electrospinning syringe was an 18G needle, the injection speed of the syringe was 1.2mL / hr, and the distance between the receiving device and the syringe was 15cm.

[0044] Cellulose acetate nanofiber membranes are multi-component materials. The preparation method of this invention obtains a spinning solution by adding urushiol and anhydrous copper sulfate in two stages of heating and stirring time, and by quantitative and rate-controlled addition. Electrospinning is performed at a high voltage of 27kV and using an 18G needle with the needle 15cm away from the collecting roller.

[0045] like Figure 1 As shown, the cellulose acetate nanofiber membrane is composed of fibers of different sizes ranging from 50 nm to 800 nm in diameter, with the main peak size of the fibers being between 100 nm and 300 nm.

[0046] Example 2

[0047] A method for preparing a cellulose acetate nanofiber membrane includes the following steps:

[0048] 1) Cellulose acetate and N,N-dimethylacetamide were mixed and heated to 60°C at a rate of 10°C / hour under magnetic stirring at 600 rpm, and stirred at this temperature for 6 hours (heated in a water bath) to obtain a first mixture. Urushiol was added to the first mixture at a flow rate of 0.1 g / h. When the mass ratio of urushiol to cellulose acetate was 1:5, the addition of urushiol was stopped to obtain a second mixture, wherein the cellulose acetate was 15 wt% of N,N-dimethylacetamide. The method for preparing urushiol was as follows: raw lacquer and anhydrous ethanol were mixed, sonicated for 1 hour, impurities were filtered, and rotary evaporated at 182°C until all the anhydrous ethanol was evaporated to obtain urushiol. The volume ratio of raw lacquer to anhydrous ethanol was 1:4.

[0049] 2) Under magnetic stirring at 600 rpm, the second mixture is heated to 80°C at a rate of 10°C / hour and stirred at this temperature for 4 hours to obtain the third mixture. The mixture is then cooled to room temperature (20-25°C). Anhydrous copper sulfate is added to the third mixture at a flow rate of 0.05 g / h under stirring at 700 rpm. When the mass ratio of anhydrous copper sulfate to urushiol is 1:4, the addition of anhydrous copper sulfate is stopped, and stirring is continued for 4 hours to obtain the spinning solution.

[0050] 3) The spinning solution was electrospun to obtain cellulose acetate nanofiber membrane. The electrospinning voltage was 27kV, the electrospinning syringe was an 18G needle, the injection speed of the syringe was 1.2mL / hr, and the distance between the receiving device and the syringe was 15cm.

[0051] Example 3

[0052] A method for preparing a cellulose acetate nanofiber membrane includes the following steps:

[0053] 1) Cellulose acetate and N,N-dimethylacetamide were mixed and heated to 60°C at a rate of 12°C / hour under magnetic stirring at 600 rpm, and stirred at this temperature for 8 hours (heated in a water bath) to obtain a first mixture. Urushiol was added to the first mixture at a flow rate of 0.15 g / h. When the mass ratio of urushiol to cellulose acetate was 1:5, the addition of urushiol was stopped to obtain a second mixture, wherein the cellulose acetate was 12 wt% of N,N-dimethylacetamide. The method for preparing urushiol was as follows: raw lacquer and anhydrous ethanol were mixed, sonicated for 1 hour, impurities were filtered, and rotary evaporated at 180°C until all the anhydrous ethanol was evaporated to obtain urushiol. The volume ratio of raw lacquer to anhydrous ethanol was 1:4.

[0054] 2) Under magnetic stirring at 600 rpm, the second mixture is heated to 80°C at a rate of 10°C / hour and stirred at this temperature for 4 hours to obtain the third mixture. The mixture is then cooled to room temperature (20-25°C). Anhydrous copper sulfate is added to the third mixture at a flow rate of 0.05 g / h under stirring at 700 rpm. When the mass ratio of anhydrous copper sulfate to urushiol is 1:4, the addition of anhydrous copper sulfate is stopped, and stirring is continued for 4 hours to obtain the spinning solution.

[0055] 3) The spinning solution was electrospun to obtain cellulose acetate nanofiber membrane. The electrospinning voltage was 27kV, the electrospinning syringe was an 18G needle, the injection speed of the syringe was 1.2mL / hr, and the distance between the receiving device and the syringe was 15cm.

[0056] Example 4

[0057] A method for preparing a cellulose acetate nanofiber membrane includes the following steps:

[0058] 1) Cellulose acetate and N,N-dimethylacetamide were mixed and heated to 60°C at a rate of 10°C / hour under magnetic stirring at 700 rpm, and stirred at this temperature for 6 hours (heated in a water bath) to obtain a first mixture. Urushiol was added to the first mixture at a flow rate of 0.1 g / h. When the mass ratio of urushiol to cellulose acetate was 1:5, the addition of urushiol was stopped to obtain a second mixture, wherein the cellulose acetate was 15 wt% of N,N-dimethylacetamide. The method for preparing urushiol was as follows: raw lacquer and anhydrous ethanol were mixed, sonicated for 1 hour, impurities were filtered, and rotary evaporated at 180°C until all the anhydrous ethanol was evaporated to obtain urushiol. The volume ratio of raw lacquer to anhydrous ethanol was 1:3.

[0059] 2) Under magnetic stirring at 600 rpm, the second mixture is heated to 80°C at a rate of 12°C / h and stirred at this temperature for 6h to obtain the third mixture. The mixture is then cooled to room temperature (20~25°C). Anhydrous copper sulfate is added to the third mixture at a flow rate of 0.08 g / h under stirring at 600 rpm. When the mass ratio of anhydrous copper sulfate to urushiol is 1:5, the addition of anhydrous copper sulfate is stopped, and stirring is continued for 6h to obtain the spinning solution.

[0060] 3) The spinning solution was electrospun to obtain cellulose acetate nanofiber membrane. The electrospinning voltage was 27kV, the electrospinning syringe was an 18G needle, the injection speed of the syringe was 1.2mL / hr, and the distance between the receiving device and the syringe was 15cm.

[0061] Example 5

[0062] A method for preparing a cellulose acetate nanofiber membrane includes the following steps:

[0063] 1) Cellulose acetate and N,N-dimethylacetamide were mixed and heated to 60°C at a rate of 10°C / hour under magnetic stirring at 700 rpm, and stirred at this temperature for 6 hours (heated in a water bath) to obtain a first mixture. Urushiol was added to the first mixture at a flow rate of 0.1 g / h. When the mass ratio of urushiol to cellulose acetate was 1:5, the addition of urushiol was stopped to obtain a second mixture, wherein the cellulose acetate was 15 wt% of N,N-dimethylacetamide. The method for preparing urushiol was as follows: raw lacquer and anhydrous ethanol were mixed, sonicated for 1 hour, impurities were filtered, and rotary evaporated at 180°C until all the anhydrous ethanol was evaporated to obtain urushiol. The volume ratio of raw lacquer to anhydrous ethanol was 1:3.

[0064] 2) Under magnetic stirring at 700 rpm, the second mixture is heated to 80°C at a rate of 10°C / hour and stirred at this temperature for 4 hours to obtain the third mixture. The mixture is then cooled to room temperature (20~25°C). Anhydrous copper sulfate is added to the third mixture at a flow rate of 0.05 g / h under stirring at 700 rpm. When the mass ratio of anhydrous copper sulfate to urushiol is 1:4, the addition of anhydrous copper sulfate is stopped, and stirring is continued for 4 hours to obtain the spinning solution.

[0065] 3) The spinning solution was electrospun to obtain cellulose acetate nanofiber membrane. The electrospinning voltage was 27.5kV, the electrospinning syringe was an 18G needle, the injection speed of the syringe was 1mL / hr, and the distance between the receiving device and the syringe was 20 cm.

[0066] Example 6

[0067] A method for preparing a cellulose acetate nanofiber membrane includes the following steps:

[0068] 1) Cellulose acetate and N,N-dimethylacetamide were mixed and heated to 60°C at a rate of 10°C / hour under magnetic stirring at 700 rpm, and stirred at this temperature for 6 hours (heated in a water bath) to obtain a first mixture. Urushiol was added to the first mixture at a flow rate of 0.1 g / h. When the mass ratio of urushiol to cellulose acetate was 1:5, the addition of urushiol was stopped to obtain a second mixture, wherein the cellulose acetate was 15 wt% of N,N-dimethylacetamide. The method for preparing urushiol was as follows: raw lacquer and anhydrous ethanol were mixed, sonicated for 1 hour, impurities were filtered, and rotary evaporated at 180°C until all the anhydrous ethanol was evaporated to obtain urushiol. The volume ratio of raw lacquer to anhydrous ethanol was 1:3.

[0069] 2) Under magnetic stirring at 700 rpm, the second mixture is heated to 80°C at a rate of 10°C / hour and stirred at this temperature for 4 hours to obtain the third mixture. The mixture is then cooled to room temperature (20~25°C). Anhydrous copper sulfate is added to the third mixture at a flow rate of 0.05 g / h under stirring at 700 rpm. When the mass ratio of anhydrous copper sulfate to urushiol is 1:4, the addition of anhydrous copper sulfate is stopped, and stirring is continued for 4 hours to obtain the spinning solution.

[0070] 3) The spinning solution was electrospun to obtain cellulose acetate nanofiber membrane. The electrospinning voltage was 26kV, the electrospinning syringe was an 18G needle, the injection speed of the syringe was 1.2mL / hr, and the distance between the receiving device and the syringe was 20cm.

[0071] Comparative Example 1

[0072] A method for preparing a blank cellulose acetate nanofiber membrane includes the following steps:

[0073] 1) Mix cellulose acetate and N,N-dimethylacetamide, heat to 60°C at a rate of 10°C / hour under magnetic stirring at 700 rpm, and stir at this temperature for 6 hours (heating in a water bath) to obtain a blank cellulose acetate spinning solution;

[0074] 2) Electrospinning the blank cellulose acetate spinning solution to obtain a blank cellulose acetate nanofiber membrane. The electrospinning voltage was 18kV, the electrospinning syringe was an 18G needle, the injection speed of the syringe was 1.2mL / hr, and the distance between the receiving device and the syringe was 15cm.

[0075] Examples 7-9

[0076] The antibacterial test was performed using the cellulose acetate nanofiber membrane prepared in Example 1 or the blank cellulose acetate nanofiber membrane prepared in Comparative Example 1. The steps are as follows:

[0077] (1) Preparation of culture medium: Prepare 200 mL of LB liquid medium (the composition of LB liquid medium is: 200 mL water, 1 g yeast extract, 2 g NaCl, 2 g peptone) and 100 mL of LB solid medium (the composition of LB solid medium is: 100 mL water, 0.5 g yeast extract, 1 g NaCl, 1 g peptone, 1.6 g agar powder). Seal the LB liquid medium and LB solid medium separately and sterilize them at high temperature for 30 min. After sterilization, pour the LB solid medium into petri dishes to make culture plates, 12 mL of LB solid medium per plate, and let them cool and solidify.

[0078] (2) Activation of bacterial strains: Add 5 mL of LB liquid medium to each test tube, and take 20 μL of bacterial suspension. The concentration of bacteria in the bacterial suspension is 10. 8 -10 9 The CFU / mL solution was placed in different test tubes for shake flask activation and cultured at 37℃ in a constant temperature air shaker at 220 rpm for 18 hours to obtain the first bacterial culture.

[0079] (3) Inoculation: Add 5 mL of LB liquid culture medium to a test tube, take 50 μL of the first bacterial solution, add a 5*5 cm cellulose acetate nanofiber membrane prepared in Example 1 or a blank cellulose acetate nanofiber membrane prepared in Comparative Example 1 (the membrane in Table 1 below), and culture in a shaker at 37°C for 24 h at a speed of 220 rpm to obtain the second bacterial solution.

[0080] (4) Spreading: Take 100 μL of the second bacterial solution, add 900 μL of high-temperature sterilized deionized water for dilution, and repeat six times to obtain bacterial solution diluted 6 times (take 100 μL and add 900 μL of high-temperature sterilized deionized water each time). Spread 100 μL of the bacterial solution diluted 6 times on the culture plate and place it in a 37℃ constant temperature incubator for 24 hours.

[0081] The bacteria used were Staphylococcus aureus or Escherichia coli (purchased from Nanjing Bianzhen Biotechnology Co., Ltd.).

[0082] Table 1

[0083]

[0084] The antibacterial effect after 24 hours of incubation is as follows Figure 2 As shown, by Figure 2 It can be seen that, compared with the blank cellulose acetate nanofiber membrane group, the cellulose acetate nanofiber membrane exhibits excellent antibacterial activity against Staphylococcus aureus and Escherichia coli.

[0085] The cellulose acetate nanofiber membrane obtained in Example 1 was immersed in 60 wt%, 80 wt%, and 98 wt% sulfuric acid aqueous solutions for 1 hour. The resulting photographs are shown below. Figure 3 As shown, by Figure 3 It can be seen that cellulose acetate nanofiber membranes have strong acid resistance and can maintain their intact morphology in sulfuric acid aqueous solutions of different mass fractions.

[0086] 2 mL of 98 wt% concentrated sulfuric acid was dropped onto the surface of the cellulose acetate nanofiber membrane obtained in Example 1. The photograph taken after 30 minutes is shown below. Figure 4 As shown, by Figure 4 It can be seen that a 98 wt% sulfuric acid aqueous solution will not penetrate the cellulose acetate nanofiber membrane.

[0087] The cellulose acetate nanofiber membrane prepared in Example 1 and the blank cellulose acetate nanofiber membrane prepared in Comparative Example 1 were used as films, and the Osaka Microbiology Laboratory was commissioned to test the inactivation effect of the films on influenza A virus H3N2 in accordance with the ISO 21702 test standard.

[0088] [Test Method] ISO 21702:2019

[0089] [Test virus] Influenza A virus (H3N2): ATCC VR-1679

[0090] [Test Results]

[0091] Virus solution concentration used for testing: 2.2 × 10⁻⁶ 7 PFU / mL

[0092] Table 2

[0093]

[0094] * Test solution contact volume: 0.4 mL (covering film surface area: 16 cm²) 2 )

[0095] The cellulose acetate nanofiber membrane prepared in Example 1 and the blank cellulose acetate nanofiber membrane prepared in Comparative Example 1 were compared at a contact depth of 2.2 × 10⁻⁶. 7 PFU / mL H3N2 virus suspension, photo taken 24 hours after inoculation. Figure 5 As shown, by Figure 5 It can be seen that the infection value of the cellulose acetate nanofiber membrane prepared in Example 1 is lower than that of the blank cellulose acetate nanofiber membrane prepared in Comparative Example 1, indicating that the cellulose acetate nanofiber membrane has a strong inactivation effect on H3N2 virus.

[0096] The morphology, antibacterial properties, acid resistance, and antiviral properties of the cellulose acetate nanofiber membrane obtained in Example 2 were basically the same as those in Example 1.

[0097] Example 3 is basically the same as Example 1, and the morphology, antibacterial properties, acid resistance and antiviral properties of the cellulose acetate nanofiber membrane obtained are basically the same as those in Example 1.

[0098] The cellulose acetate nanofiber membranes obtained in Example 4 were immersed in 60 wt%, 80 wt%, and 98 wt% sulfuric acid aqueous solutions for 1 hour. The resulting photographs are shown below. Figure 6 As shown, by Figure 6 It can be seen that cellulose acetate nanofiber membranes have strong acid resistance and can maintain their intact morphology in sulfuric acid aqueous solutions of different mass fractions.

[0099] 2 mL of 98 wt% concentrated sulfuric acid was dropped onto the surface of the cellulose acetate nanofiber membrane obtained in Example 4. The photograph taken after 30 minutes is shown below. Figure 7 As shown, by Figure 7 It can be seen that a 98 wt% sulfuric acid aqueous solution will not penetrate the cellulose acetate nanofiber membrane.

[0100] The cellulose acetate nanofiber membrane obtained in Example 5 was immersed in 60 wt%, 80 wt%, and 98 wt% sulfuric acid aqueous solutions for 1 hour. The resulting photographs are shown below. Figure 8 As shown, by Figure 8 It can be seen that cellulose acetate nanofiber membranes have strong acid resistance and can maintain their intact morphology in sulfuric acid aqueous solutions of different mass fractions.

[0101] 2 mL of 98 wt% concentrated sulfuric acid was dropped onto the surface of the cellulose acetate nanofiber membrane obtained in Example 5. The photograph taken after 30 minutes is shown below. Figure 9 As shown, by Figure 9 It can be seen that a 98 wt% sulfuric acid aqueous solution will not penetrate the cellulose acetate nanofiber membrane.

[0102] The cellulose acetate nanofiber membrane obtained in Example 6 was immersed in 60 wt%, 80 wt%, and 98 wt% sulfuric acid aqueous solutions for 1 hour. The resulting photographs are shown below. Figure 10 As shown, by Figure 10 It can be seen that cellulose acetate nanofiber membranes have strong acid resistance and can maintain their intact morphology in sulfuric acid aqueous solutions of different mass fractions.

[0103] 2 mL of 98 wt% concentrated sulfuric acid was dropped onto the surface of the cellulose acetate nanofiber membrane obtained in Example 6. The photograph taken after 30 minutes is shown below. Figure 11 As shown, by Figure 11 It can be seen that a 98 wt% sulfuric acid aqueous solution will not penetrate the cellulose acetate nanofiber membrane.

[0104] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.

Claims

1. Use of an acid-resistant agent for improving acid resistance of cellulose acetate, characterized in that, The application discloses a preparation method of an acetyl cellulose nanofiber membrane, and belongs to the technical field of nanofiber membranes. 1) mixing acetyl cellulose and N,N-dimethylacetamide, and stirring under the condition of temperature rising to 50-60 DEG C and temperature keeping for 6-8 hours to obtain a first mixed solution; adding urushiol into the first mixed solution at a flow rate of 0.1-0.15 g / h, and stopping adding the urushiol when the mass ratio of the urushiol to the acetyl cellulose is 1: (4-5), so as to obtain a second mixed solution, wherein the acetyl cellulose is 12-15 wt% of N,N-dimethylacetamide; 2) stirring the second mixed solution under the condition of temperature rising to 70-80 DEG C and temperature keeping for 4-6 hours to obtain a third mixed solution, cooling to room temperature, and adding anhydrous copper sulfate into the third mixed solution at a flow rate of 0.05-0.08 g / h under the condition of stirring, and stopping adding the anhydrous copper sulfate when the mass ratio of the anhydrous copper sulfate to the urushiol is 1: (4-5), and continuing stirring for 4-6 hours to obtain a spinning solution; 3) electrospinning the spinning solution to obtain the acetyl cellulose nanofiber membrane.

2. Use according to claim 1, characterized in that, In the step 1), the rate of temperature rising to 50-60 DEG C is 10-12 DEG C / hour.

3. Use according to claim 1, characterized in that, In the step 1), the method for preparing the urushiol is mixing raw lacquer and anhydrous ethanol, ultrasonicating, filtering impurities, and rotary evaporating at 180-182 DEG C until the anhydrous ethanol is completely evaporated to obtain the urushiol, wherein the ratio of the raw lacquer to the anhydrous ethanol is 1: (3-4) by volume fraction.

4. Use according to claim 3, characterized in that, The ultrasonicating time is 1-1.5 hours.

5. The use according to claim 1, characterized in that, In the step 2), the rate of temperature rising to 70-80 DEG C is 10-12 DEG C / hour.

6. Use according to claim 1, characterized in that, In the step 3), the spinning voltage of the electrospinning is 26-28 kV.

7. Use according to claim 1, characterized in that, In the step 3), the needle of the syringe for the electrospinning is 18G, the injection speed of the syringe is 1-1.2 ml / hour, and the distance between the receiving device and the syringe is 15-20 cm.

8. The use according to claim 1, characterized in that, The stirring speed is 600-700 rpm.

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