Bismuth ion filtration membrane manufacturing method and its application

Abstract

In the manufacturing method of a bismuth ion filtration membrane and its application, the manufacturing method includes the steps of: putting a filtration membrane substrate into a washing machine, adding a non-ionic chelating agent solution and water, treating for 1 to 2 hours, and dehydrating after the treatment to obtain a filtration membrane substrate A; putting the filtration membrane substrate A and a chelating bismuth ion solution into a reactor, adding a non-ionic chelating agent solution to react, and obtaining a filtration membrane substrate embedded with bismuth ions after the reaction is complete; and dehydrating and drying the filtration membrane substrate embedded with bismuth ions to obtain a bismuth ion filtration membrane.

Description

[Technical Field]

[0001] The present invention relates to the technical field of membrane filtration production, and more particularly to a method for producing a bismuth ion membrane filtration and its application. [Background technology]

[0002] In recent years, due to the severity of epidemics, different ionic bactericidal materials have been used in masks and air filters, and in addition to the silver ions that have been used until now, there has been progress in materials such as platinum and gold. Empirical evidence shows that platinum ions have better and more stable sterilization properties than silver ions, and that they also generate more negative oxygen ions in the mask. Therefore, platinum ions are superior to silver ions. Unfortunately, platinum is relatively expensive and requires 10 times the amount of manufacturing materials as silver, making it less cost-effective. In addition, platinum is manufactured using gold ions, which makes it more expensive.

[0003] We have found that bismuth ions have a reinforcing effect on other metal ions in applications. In particular, bismuth plays a very important role in applications to disinfectants during the recent COVID-19 pandemic. Bismuth not only reinforces the bactericidal and virus-killing abilities of ions, but also reduces costs, improves efficacy, and provides additional benefits. For example, it is very clear that silver ions can sterilize and disinfect, but they are expensive and costly. Also, platinum ions have better sterilizing properties, but they are even more expensive than silver. Therefore, when bismuth ions were added to the silver and platinum materials, the performance of the materials improved significantly, further reducing the cost of using precious metals. Tests have also shown that the cost of precious metals can be reduced by 5 to 10 times with the same sterilization ability. Furthermore, bismuth ions possess a photocatalytic effect, which provides additional sterilization capabilities. Under photocatalytic conditions, bismuth can enhance the micro-EMC response, enabling sterilization within a distance of 1 to 3 feet. This is a significant added value and improves the functional utility of the material.

[0004] It is known that the most effective positive-negative electrode air purifiers on the market generate approximately 10,000 negative oxygen ions, but because these are generated using electrodes, there is a risk that the amount of ozone and hydroxyl radicals generated may exceed the standard. Naturally, the number of negative oxygen ions generated by typical commercially available air purifiers is around 2,000 to 6,000. However, bismuth ion filtration membranes can generate over 3 million negative oxygen ions without the need for electrodes, making them an extremely economical and environmentally friendly application material.

[0005] In the prior art, Patent Document 1 discloses a method for producing a bismuth ion filtration membrane and its applications. However, in Patent Document 1, bismuth ions are merely supported on a filtration membrane substrate, and the bonding strength between the bismuth ions and the filtration membrane substrate is not strong. Therefore, the bismuth ions may fall off during subsequent washing with water, potentially reducing the antibacterial performance of the filtration membrane. Therefore, in the present application, bismuth ions are introduced into flake graphite through a chemical reaction, and then the flake graphite is introduced into the filtration membrane substrate. This increases the bonding strength between the bismuth ions and the filtration membrane substrate, thereby improving the washing resistance of the bismuth ion filtration membrane. Furthermore, Patent Document 2 discloses preparing a sol by mixing bismuth tungsten oxide with an organic agent containing chitosan. Patent Document 2 combines metal ion technology, organic material technology, and photocatalytic technology, while supplementing it with the adsorption and dust-proofing properties of graphene and / or activated carbon. This provides the mask with long-term, effective anti-smog, anti-epidemic, and anti-coronavirus capabilities without affecting breathability, and also provides catalytic decomposition of harmful gases such as formaldehyde and benzene in the air. Patent Document 2 combines silver ions, inorganic agents, and organic agents. However, the nano-bismuth tungsten oxide in the inorganic agent acts as a photocatalyst, which differs from the bismuth ions in the present application. Patent Document 2 also fails to suggest that adding flake graphite and chitosan can improve the bonding strength between bismuth ions and the filtration membrane substrate. Furthermore, the bismuth tungsten oxide added in Patent Document 2 is an inorganic agent. It is an inorganic particle that is insoluble in water and cannot be adsorbed by chitosan, making it impossible to form the chelating bismuth ions described in the present application. On the other hand, the bismuth ion solution used in the present application is a water-soluble bismuth ion-containing solution that can form chelating bismuth ions by adsorption by flake graphite and chitosan. Therefore, although Patent Document 2 and the present application use the same added substance, they have completely different effects. Furthermore, Patent Document 3 discloses a highly conductive graphene film and a method for producing the same. In Patent Document 3, sheet-like graphite is formed by reacting flake graphite with sulfuric acid and hydrogen peroxide.However, the specification of Patent Document 3 clearly indicates that ultrasonic dispersion is not used to prevent damage to the crystalline structure of graphene oxide caused by ultrasonic waves, resulting in a decrease in the diameter of the graphene oxide. In contrast, the sheet-like flake graphite prepared in the present application requires ultrasonic treatment for 8 to 12 hours. Therefore, although the preparation method for the sheet graphite presented in Patent Document 3 is similar to that of the present application, the actual preparation process is completely different from that of the present application. This is because Patent Document 3 primarily aims to improve the conductivity of the graphene film being prepared, while the present application aims to improve the adsorption properties of the flake graphite. Therefore, if the preparation methods, functions, and effects achieved are completely different, the sheet graphite in Patent Document 3 and the present application cannot be said to be the same flake graphite. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Chinese Patent Application Publication No. 116059836 [Patent Document 2] Chinese Patent Application Publication No. 114855448 [Patent Document 3] Chinese Patent Application Publication No. 115448299 Summary of the Invention [Problem to be solved by the invention]

[0007] In view of the deficiencies of the prior art, the present invention provides a method for producing a bismuth ion filtration membrane and its application. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides the following technical means.

[0009] The method for producing a bismuth ion filtration membrane includes the following steps:

[0010] (1) Pretreatment of the filtration membrane substrate: The filtration membrane substrate is placed in a washer, and a nonionic chelating agent solution and water are added, followed by immersion and agitation. After completion of the treatment, the substrate is dehydrated to obtain the filtration membrane substrate A.

[0011] (2) Embedding bismuth ions: The filtration membrane substrate A obtained in step (1) and the chelating bismuth ion solution are placed in a reactor, and then a non-ionic chelating agent solution is added to react. After the reaction is complete, a filtration membrane substrate embedded with bismuth ions is obtained.

[0012] (3) Post-treatment: The bismuth ion-embedded filtration membrane substrate obtained in step (2) is subjected to dehydration and drying treatment to obtain a bismuth ion filtration membrane.

[0013] Preferably, the filtration membrane substrate in step (1) is a nonwoven fabric, the nonionic chelating agent is ammonium EDTA, and the concentration of the nonionic chelating agent solution is 1 mol / L.

[0014] Preferably, the time for the immersion and stirring treatment in step (1) is 1 to 2 hours.

[0015] Preferably, the mass ratio of the filtration membrane substrate to water in step (1) is 4 to 8:50, and the mass ratio of the nonionic chelating agent solution to water is 1:100 to 1000.

[0016] Preferably, the method for preparing the chelating bismuth ion solution in step (2) comprises the following steps:

[0017] S1: The flake graphite is added to an H2O2 / H2SO4 solution and stirred at room temperature for 10 minutes, then filtered and washed, and calcined in a nitrogen gas atmosphere at 500-600°C for 10-20 minutes to obtain pretreated flake graphite. The pretreated flake graphite is then added to an ethanol aqueous solution in a volume ratio of 1:1, and ultrasonically treated under stirring for 8-12 hours. After vacuum drying, sheet graphite is obtained.

[0018] S2: The sheet graphite from step S1 is placed in an aqueous ethanol solution, and then 3-glycidyloxypropyltrimethoxysilane is added and stirred to cause a reaction. After the reaction is complete, the mixture is filtered, washed, and dried to obtain pretreated sheet graphite. Next, the pretreated sheet graphite is placed in dimethyl sulfoxide, and then 2-guanidinobenzimidazole is added to adjust the pH to 10-12. The mixture is then reacted at a constant temperature in a nitrogen gas atmosphere to obtain modified sheet graphite after the reaction is complete.

[0019] S3: 50 parts by weight of the sheet graphite in step S2 is added to 920 parts by weight of deionized water, and then 10 parts by weight of chitosan is added to adjust the pH to 2-3. Then, the mixture is stirred at 40-50°C for 4-6 hours, and after the reaction is completed, 20 parts by weight of Bismuth ion solution This is reacted at 60 to 70°C for 3 to 4 hours, and after the reaction is completed, the chelating bismuth ion solution is obtained.

[0020] Preferably, in step S2, the volume ratio of ethanol to water in the ethanol aqueous solution is 7-8:2-3, the mass ratio of the sheet graphite to 3-glycidyloxypropyltrimethoxysilane is 50:5-8, the stirring reaction temperature is 60-70°C, and the reaction time is 2-4 hours. Alternatively, the mass ratio of the pretreated sheet graphite to 2-guanidinobenzimidazole is 50:4-6, the stirring reaction temperature is 80-90°C, and the reaction time is 3-5 hours.

[0021] Preferably, the nonionic chelating agent in step (2) is ammonium EDTA, the concentration of the nonionic chelating agent solution is 1 mol / L, the mass ratio of the filtration membrane substrate A to the chelating bismuth ion solution is 4 to 8:50, and the mass ratio of the nonionic chelating agent solution to the chelating bismuth ion solution is 1:100 to 1000.

[0022] Preferably, the reaction temperature in step (2) is 30-40° C., the reaction time is 10-30 minutes, the reaction gas pressure is 0.1-0.15 MPa, and the pH is 6-7.

[0023] Preferably, the drying temperature in step (3) is 60 to 90° C., and the drying time is 4 to 8 hours.

[0024] The present invention further protects the bismuth ion filtration membrane produced by the above-described production method.

[0025] The present invention further covers the application of said bismuth ion filtration membrane in masks and air filters. [Effects of the Invention]

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) This invention is the first to propose the application of bismuth ions to masks and air filters. Test results showed that masks and filters made with bismuth ions were able to generate over 3 million negative oxygen ions, the exact number depending on the concentration of bismuth ions used during manufacturing.

[0028] (2) The bismuth ion filtration membrane produced by the present invention is obtained by subjecting flake graphite to oxidation, acidification, and ultrasonic treatment to obtain graphite with a good layered crystal structure. In addition, by increasing the number of oxygen-containing functional groups on the graphite surface, this is advantageous for the progress of subsequent reactions. Then, the sheet graphite is reacted with 3-glycidyloxypropyltrimethoxysilane. This, first, improves the dispersibility of the sheet graphite. Second, it introduces reactive epoxy groups into the sheet graphite, making it favorable for subsequent reactions. Next, the epoxy-containing sheet graphite is reacted with 2-guanidinobenzimidazole to graft the 2-guanidinobenzimidazole onto the graphite. 2-guanidinobenzimidazole contains a benzimidazole ring and a guanidine group. This, first, significantly improves the antibacterial properties of the graphite because the guanidine group has good antibacterial properties. Second, the heterocyclic benzimidazole group acts as a chelating bismuth ion, allowing the graphite to carry more bismuth ions in subsequent reactions. The bismuth ions and guanidine groups work together to improve the antibacterial properties and long-term antibacterial properties of the graphite. The sheet graphite is then reacted with chitosan to support the chitosan on the graphite surface. Chitosan contains a large number of active groups, such as amino and carboxyl groups, which react with the oxidized graphite, improving the bond strength between the chitosan and graphite. Furthermore, chitosan has good adsorption properties, which can increase the amount of bismuth ions carried in the graphite, and can also improve the bonding strength between the graphite and the filtration membrane substrate, making the bismuth-ion-containing graphite less likely to peel off, thereby ensuring that the resulting filtration membrane has long-term antibacterial properties.

[0029] (3) The bismuth ion filtration membrane produced by this invention incorporates bismuth ions into flake graphite through a chemical reaction, and then incorporates the flake graphite into the filtration membrane substrate. This allows the photocatalytic effect of the bismuth ions to exert a bactericidal effect within a distance of 1 to 3 feet. Furthermore, the structure of the bismuth ions makes it possible to increase the amount of negative oxygen ions generated during air filtration. Using bismuth ions to produce filtration membranes and masks provides the most cost-effective material, 10 times cheaper than silver ions, making them both economical and practical. DETAILED DESCRIPTION OF THE INVENTION

[0030] The following provides a clear and concise description of the technical solutions of the present invention by combining specific embodiments of the present invention. It goes without saying that the described embodiments are only a part of the present invention, not all of the embodiments. Furthermore, all other embodiments that can be obtained by those skilled in the art based on the embodiments of the present invention without any creative work are also within the scope of protection of the present invention.

[0031] All raw materials in the examples of the present invention are commercially available, including a non-ionic chelating agent (ammonium EDTA), Bismuth ion solution is available for purchase from the Aten Group. Bismuth ion solution The concentration of bismuth ions in the solution was set to 5%. [Example]

[0032] The manufacturing method of the bismuth ion filtration membrane included the following steps.

[0033] (1) Pretreatment of filtration membrane substrate: 4 kg of nonwoven fabric was placed in a washer, and 50 kg of water and 500 mL of 1 mol / L diammonium EDTA were added. The nonwoven fabric was immersed and stirred for 1 hour. After the treatment was completed, the nonwoven fabric was dehydrated to obtain filtration membrane substrate A.

[0034] (2) Embedding of bismuth ions: 4 kg of the filtration membrane substrate A obtained in step (1) and 50 kg of the chelating bismuth ion solution were placed in a reactor, and 500 g of 1 mol / L EDTA ammonium was added to adjust the pH to 6 and the reaction gas pressure to 0.1 MPa. The reaction was then carried out at 30°C for 10 minutes, and after the reaction was completed, a filtration membrane substrate embedded with bismuth ions was obtained.

[0035] (3) Post-treatment: The bismuth ion-embedded filtration membrane substrate obtained in step (2) was dehydrated and then dried at 70°C for 6 hours to obtain a bismuth ion filtration membrane.

[0036] The preparation method of the chelating bismuth ion solution included the following steps:

[0037] S1: Scaly graphite was added to an H2O2 / H2SO4 solution (the volume ratio of H2O2 / H2SO4 was 1:3. The mass concentration of H2O2 was 30%, and the mass concentration of H2SO4 was 98%) and stirred at room temperature for 10 minutes. It was then filtered and washed, and calcined in a nitrogen gas atmosphere at 500°C for 20 minutes to obtain pretreated scaly graphite. The pretreated scaly graphite was then added to an aqueous ethanol solution at a volume ratio of 1:1, and ultrasonically treated for 10 hours under stirring. After vacuum drying, sheet graphite was obtained.

[0038] S2: 50g of the sheet graphite from step S1 was added to 920g of deionized water, and then 10g of chitosan was added and the pH was adjusted to 2.5. Then, the mixture was stirred at 45°C for 5 hours, and after the reaction was completed, 20g of Bismuth ion solution The mixture was reacted at 65°C for 3.5 hours, and after the reaction was completed, the chelating bismuth ion solution was obtained. [Example]

[0039] The manufacturing method of the bismuth ion filtration membrane included the following steps.

[0040] (1) Pretreatment of filtration membrane substrate: 5 kg of nonwoven fabric was placed in a washer, and 50 kg of water and 500 mL of 1 mol / L diammonium EDTA were added. The nonwoven fabric was immersed and stirred for 1.5 hours. After the treatment was completed, the nonwoven fabric was dehydrated to obtain filtration membrane substrate A.

[0041] (2) Embedding of bismuth ions: 5 kg of the filtration membrane substrate A obtained in step (1) and 50 kg of the chelating bismuth ion solution were placed in a reactor, and 500 g of 1 mol / L EDTA ammonium was added to adjust the pH to 6.5 and the reaction gas pressure to 0.1 MPa. The reaction was then carried out at 40°C for 10 minutes, and after the reaction was completed, a filtration membrane substrate embedded with bismuth ions was obtained.

[0042] (3) Post-treatment: The bismuth ion-embedded filtration membrane substrate obtained in step (2) was dehydrated and then dried at 80°C for 6 hours to obtain a bismuth ion filtration membrane.

[0043] The preparation method of the chelating bismuth ion solution included the following steps:

[0044] S1: Scaly graphite was added to an H2O2 / H2SO4 solution (the volume ratio of H2O2 / H2SO4 was 1:3. The mass concentration of H2O2 was 30%, and the mass concentration of H2SO4 was 98%) and stirred at room temperature for 10 minutes. It was then filtered and washed, and calcined in a nitrogen gas atmosphere at 550°C for 15 minutes to obtain pretreated scaly graphite. The pretreated scaly graphite was then added to an aqueous ethanol solution in a volume ratio of 1:1, and ultrasonically treated under stirring for 10 hours. After vacuum drying, sheet graphite was obtained.

[0045] S2: 50g of the sheet graphite from step S1 was added to 920g of deionized water, and then 10g of chitosan was added and the pH was adjusted to 2.5. Then, the mixture was stirred at 45°C for 5 hours, and after the reaction was completed, 20g of Bismuth ion solution The mixture was reacted at 65°C for 3.5 hours, and after the reaction was completed, the chelating bismuth ion solution was obtained. [Example]

[0046] The manufacturing method of the bismuth ion filtration membrane included the following steps.

[0047] (1) Pretreatment of filtration membrane substrate: 6 kg of nonwoven fabric was placed in a washer, and 50 kg of water and 500 mL of 1 mol / L diammonium EDTA were added. The nonwoven fabric was immersed and stirred for 1 hour. After the treatment was completed, the nonwoven fabric was dehydrated to obtain filtration membrane substrate A.

[0048] (2) Embedding of bismuth ions: 6 kg of the filtration membrane substrate A obtained in step (1) and 50 kg of the chelating bismuth ion solution were placed in a reactor, and 500 g of 1 mol / L ammonium EDTA was added to adjust the pH to 7 and the reaction gas pressure to 0.15 MPa. The reaction was then carried out at 40°C for 20 minutes, and after the reaction was completed, a filtration membrane substrate embedded with bismuth ions was obtained.

[0049] (3) Post-treatment: The bismuth ion-embedded filtration membrane substrate obtained in step (2) was dehydrated and then dried at 60°C for 7 hours to obtain a bismuth ion filtration membrane.

[0050] The preparation method of the chelating bismuth ion solution included the following steps:

[0051] S1: Scaly graphite was added to an H2O2 / H2SO4 solution (the volume ratio of H2O2 / H2SO4 was 1:3. The mass concentration of H2O2 was 30%, and the mass concentration of H2SO4 was 98%) and stirred at room temperature for 10 minutes. It was then filtered and washed, and calcined in a nitrogen gas atmosphere at 550°C for 20 minutes to obtain pretreated scaly graphite. The pretreated scaly graphite was then added to an aqueous ethanol solution in a volume ratio of 1:1, and ultrasonically treated under stirring for 8 hours. After vacuum drying, sheet graphite was obtained.

[0052] S2: 50 g of the sheet graphite from step S1 was added to 920 g of deionized water, and then 10 g of chitosan was added and the pH was adjusted to 2. Then, the mixture was stirred at 40°C for 6 hours, and after the reaction was completed, 20 g of Bismuth ion solutionThe mixture was allowed to react at 60° C. for 4 hours, and after the reaction was completed, the chelating bismuth ion solution was obtained. [Example]

[0053] The manufacturing method of the bismuth ion filtration membrane included the following steps.

[0054] (1) Pretreatment of filtration membrane substrate: 8 kg of nonwoven fabric was placed in a washer, and 50 kg of water and 500 mL of 1 mol / L diammonium EDTA were added. The nonwoven fabric was then immersed and stirred for 2 hours. After completion of the treatment, the nonwoven fabric was dehydrated to obtain filtration membrane substrate A.

[0055] (2) Embedding of bismuth ions: 8 kg of the filtration membrane substrate A obtained in step (1) and 50 kg of the chelating bismuth ion solution were placed in a reactor, and 500 g of 1 mol / L EDTA diammonium salt was added to adjust the pH to 7 and the reaction gas pressure to 0.15 MPa. The reaction was then carried out at 40°C for 30 minutes, and after the reaction was completed, a filtration membrane substrate with bismuth ions embedded was obtained.

[0056] (3) Post-treatment: The bismuth ion-embedded filtration membrane substrate obtained in step (2) was dehydrated and then dried at 90°C for 6 hours to obtain a bismuth ion filtration membrane.

[0057] The preparation method of the chelating bismuth ion solution included the following steps:

[0058] S1: Scaly graphite was added to an H2O2 / H2SO4 solution (the volume ratio of H2O2 / H2SO4 was 1:3. The mass concentration of H2O2 was 30%, and the mass concentration of H2SO4 was 98%) and stirred at room temperature for 10 minutes. It was then filtered and washed, and calcined in a nitrogen gas atmosphere at 600°C for 10 minutes to obtain pretreated scaly graphite. The pretreated scaly graphite was then added to an aqueous ethanol solution in a volume ratio of 1:1, and ultrasonically treated under stirring for 12 hours. After vacuum drying, sheet graphite was obtained.

[0059] S2: 50 parts by weight of the sheet graphite in step S1 was added to 920 parts by weight of deionized water, and then 10 parts by weight of chitosan was added to adjust the pH to 3. Then, the mixture was stirred at 50°C for 4 hours, and after the reaction was completed, 20 g of Bismuth ion solution The mixture was reacted at 70°C for 3 hours, and after the reaction was completed, the chelating bismuth ion solution was obtained. [Example]

[0060] The manufacturing method of the bismuth ion filtration membrane included the following steps. (1) Pretreatment of filtration membrane substrate: 4 kg of nonwoven fabric was placed in a washer, and 50 kg of water and 500 mL of 1 mol / L diammonium EDTA were added. The nonwoven fabric was immersed and stirred for 1 hour. After the treatment was completed, the nonwoven fabric was dehydrated to obtain filtration membrane substrate A. (2) Embedding of bismuth ions: 4 kg of the filtration membrane substrate A obtained in step (1) and 50 kg of the chelating bismuth ion solution were placed in a reactor, and 500 g of 1 mol / L EDTA ammonium was added to adjust the pH to 6 and the reaction gas pressure to 0.1 MPa. The reaction was then carried out at 30°C for 10 minutes, and after the reaction was completed, a filtration membrane substrate embedded with bismuth ions was obtained. (3) Post-treatment: The bismuth ion-embedded filtration membrane substrate obtained in step (2) was dehydrated and then dried at 70°C for 6 hours to obtain a bismuth ion filtration membrane. The preparation method of the chelating bismuth ion solution included the following steps: S1: Scaly graphite 2 O 2 / H 2 SO 4 Solution (H 2 O 2 / H 2 SO 4 The volume ratio of H 2 O 2 The mass concentration of is 30%, H 2 SO 4 The mixture was poured into a solution of 1000 kJ / kg of ethanol (the concentration of which was 98%) and stirred at room temperature for 10 minutes. It was then filtered and washed, and calcined in a nitrogen gas atmosphere at 500°C for 20 minutes to obtain pretreated flake graphite. The pretreated flake graphite was then added to an aqueous ethanol solution at a volume ratio of 1:1, and subjected to ultrasonic treatment for 10 hours under stirring conditions. After vacuum drying, sheet graphite was obtained. S2: 50 g of the sheet graphite from step S1 was added to 800 g of an aqueous ethanol solution (volume ratio of ethanol to water: 7.5:2.5), and then 7 g of 3-glycidyloxypropyltrimethoxysilane was added. The mixture was stirred at 65°C and reacted for 3 hours. After the reaction was completed, the mixture was filtered, washed, and dried to obtain pretreated sheet graphite. Next, 50 g of the pretreated sheet graphite was added to 800 g of dimethyl sulfoxide, and then 5 g of 2-guanidinobenzimidazole was added to adjust the pH to 11. The mixture was then reacted at a constant temperature of 85°C for 4 hours in a nitrogen gas atmosphere, and after the reaction was completed, modified sheet graphite was obtained. S3: 50 g of the modified sheet graphite from step S2 was added to 920 g of deionized water, and 10 g of chitosan was added to adjust the pH to 2.5. The mixture was stirred at 45°C for 5 hours, and after the reaction was complete, 20 g of bismuth ion solution was added. The mixture was then reacted at 65°C for 3.5 hours, and after the reaction was complete, the chelating bismuth ion solution was obtained.

[0061] Comparative Example 1

[0062] The manufacturing method of the bismuth ion filtration membrane included the following steps.

[0063] (1) Pretreatment of filtration membrane substrate: 4 kg of nonwoven fabric was placed in a washer, and 50 kg of water and 500 mL of 1 mol / L diammonium EDTA were added. The nonwoven fabric was immersed and stirred for 1 hour. After the treatment was completed, the nonwoven fabric was dehydrated to obtain filtration membrane substrate A.

[0064] (2) Embedding of bismuth ions: 4 kg of the filtration membrane substrate A obtained in step (1) and 50 kg of the chelating bismuth ion solution were placed in a reactor, and 500 g of 1 mol / L EDTA ammonium was added to adjust the pH to 6 and the reaction gas pressure to 0.1 MPa. The reaction was then carried out at 30°C for 10 minutes, and after the reaction was completed, a filtration membrane substrate embedded with bismuth ions was obtained.

[0065] (3) Post-treatment: The bismuth ion-embedded filtration membrane substrate obtained in step (2) was dehydrated and then dried at 70°C for 6 hours to obtain a bismuth ion filtration membrane.

[0066] The preparation method of the chelating bismuth ion solution included the following steps:

[0067] Put 50g of flake graphite into 930g of deionized water, then add 20g of Bismuth ion solution The mixture was reacted at 65°C for 3.5 hours, and after the reaction was completed, the chelating bismuth ion solution was obtained.

[0068] Antibacterial tests were carried out on the bismuth ion filtration membranes produced in Examples 1 to 5 and Comparative Example 1. The test standard was GB / T 23763-2009. The test results are shown in Table 1 below.

[0069] [Table 1]

[0070] Masks were made using the filter membranes produced in Examples 1 to 5 and Comparative Example 1, and then antibacterial performance tests were conducted on the masks. According to GB / T 20944.3-2008 "Antibacterial Performance Test" and standards, the masks were washed 50 times with water and then tested for antibacterial performance. The test results are shown in Table 2.

[0071] [Table 2]

[0072] Although embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. Accordingly, the scope of the present invention is limited by the appended claims and their equivalents.

Claims

1. A method for producing a bismuth ion filtration membrane, comprising: (1) Pretreatment of the filtration membrane substrate: Put the filtration membrane substrate into a washer, add a nonionic chelating agent solution and water, and perform immersion and stirring treatment. After the treatment is completed, dehydrate the filtration membrane substrate A to obtain it; (2) Embedding bismuth ions: Putting the filtration membrane substrate A obtained in step (1) and the chelating bismuth ion solution into a reactor, and then adding a non-ionic chelating agent solution to react with each other. After the reaction is completed, a filtration membrane substrate embedded with bismuth ions is obtained. (3) Post-treatment: performing dehydration and drying treatment on the bismuth ion-embedded filtration membrane substrate obtained in step (2) to obtain a bismuth ion filtration membrane; Including, The method for preparing the chelating bismuth ion solution in step (2) includes: S1: Scaly graphite ２ O ２ / H ２ SO ４ Add the resulting powder to the solution, stir at room temperature for 10 minutes, filter and wash the resulting powder, and calcinate it in a nitrogen gas atmosphere at 500-600°C for 10-20 minutes to obtain pretreated flake graphite. Then, add the pretreated flake graphite to an aqueous ethanol solution in a volume ratio of 1:1, and ultrasonically treat it under stirring for 8-12 hours. After vacuum drying, obtain sheet graphite. S2: Add 50 parts by weight of the sheet graphite in step S1 to 920 parts by weight of deionized water, add 10 parts by weight of chitosan, adjust the pH to 2-3, and react at 40-50°C with stirring for 4-6 hours. After the reaction is complete, add 20 parts by weight of chelating bismuth, and react at 60-70°C for 3-4 hours. After the reaction is complete, obtain the chelating bismuth ion solution. A method comprising:

2. 2. The method for producing a bismuth ion filtration membrane according to claim 1, wherein the filtration membrane substrate in step (1) is a nonwoven fabric, the nonionic chelating agent is ammonium EDTA, and the concentration of the nonionic chelating agent solution is 1 mol / L.

3. 2. The method for producing a bismuth ion filtration membrane according to claim 1, wherein the immersion and stirring time in step (1) is 1 to 2 hours.

4. 2. The method for producing a bismuth ion filtration membrane according to claim 1, wherein the mass ratio of the filtration membrane substrate to water in step (1) is 4 to 8:50, and the mass ratio of the nonionic chelating agent solution to water is 1:100 to 1000.

5. 2. The method for producing a bismuth ion filtration membrane according to claim 1, wherein the nonionic chelating agent in step (2) is ammonium EDTA, and the concentration of the nonionic chelating agent solution is 1 mol / L.

6. 2. The method for producing a bismuth ion filtration membrane according to claim 1, wherein in step (2), the mass ratio of the filtration membrane substrate A to the chelating bismuth ion solution is 4 to 8:50, and the mass ratio of the nonionic chelating agent solution to the chelating bismuth ion solution is 1:100 to 1000.

7. 2. The method for producing a bismuth ion filtration membrane according to claim 1, wherein the reaction temperature in step (2) is 30 to 40°C, the reaction time is 10 to 30 minutes, the reaction gas pressure is 0.1 to 0.15 MPa, and the pH is 6 to 7.

8. 2. The method for producing a bismuth ion filtration membrane according to claim 1, wherein the drying temperature in step (3) is 60 to 90°C, and the drying time is 4 to 8 hours.

9. A bismuth ion filtration membrane obtained by the production method according to any one of claims 1 to 8.

10. 10. The application of the bismuth ion filtration membrane according to claim 9 in masks and air filters.

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