CN105289339B - A kind of antibacterial ultrafiltration membrane and preparation method thereof and film renovation process - Google Patents

Abstract

The invention provides a kind of antibacterial ultrafiltration membrane and its preparation method and membrane regeneration method, and this antibacterial ultrafiltration membrane is prepared from the ultrafiltration membrane material with the repeating unit shown in formula I or formula II, and described formula I or The repeating unit shown in formula II contains N-Cl bond, so that the antibacterial ultrafiltration membrane prepared from the ultrafiltration membrane material having the repeating unit shown in formula I or formula II has higher bactericidal properties. In addition, the antibacterial ultrafiltration membrane has good filtration and separation performance; it can exist stably in air and water; it can be recycled; it is environmentally friendly and non-corrosive. Experimental result shows: antibacterial ultrafiltration membrane provided by the present invention has a bactericidal rate of 90% to 100% to Escherichia coli or Bacillus subtilis; 100%; the rejection rate of bovine serum albumin is above 99.2%.

Description

A kind of antibacterial ultrafiltration membrane and its preparation method and membrane regeneration method

technical field

The invention relates to the technical field of membrane separation materials, in particular to an antibacterial ultrafiltration membrane, a preparation method thereof and a membrane regeneration method.

Background technique

Membrane separation technology is a new contemporary separation technology with outstanding advantages such as high efficiency, convenient operation, no pollution to the environment, and low energy consumption. It has been widely used in the fields of water resources, environment, food, and biomedicine. Membranes can be divided into microfiltration membranes, ultrafiltration membranes, nanofiltration membranes and reverse osmosis membranes according to their pore sizes (or molecular weight cut-offs).

Ultrafiltration is a membrane separation technology that has emerged in the past 30 years and is widely used in the separation of macromolecular components and low molecular weight substances. During the use of ultrafiltration membranes, with the extension of use time, it is inevitable to encounter the problem of membrane fouling. The pollution of the ultrafiltration membrane can be roughly divided into: the adsorption pollution caused by the adsorption of organic matter and colloid on the surface of the membrane, and the microbial pollution produced by microorganisms (such as bacteria). Among them, microbial contamination is the main factor limiting the wide application of ultrafiltration membranes. Microorganisms will multiply after being adsorbed on the surface of the ultrafiltration membrane, resulting in a significant decrease in membrane flux and separation performance, and increasing the cost of use. Therefore, there is an urgent need to develop antibacterial separation membranes to prevent biofouling of ultrafiltration membranes.

The current reported literature mainly uses polysulfone and polyvinylidene fluoride as ultrafiltration membrane materials, which are realized by adding antibacterial agents. Common antibacterial agents include metal and oxidized metal nano-ions (such as nano-Ag, TiO ₂ , copper, etc.), ammonium salt. Antibacterial agents containing metals and oxidized metals are easy to lose during use, and the antibacterial performance decreases and is easy to cause harm to the environment. Antibacterial films containing quaternary ammonium salts tend to develop drug resistance after long-term use, reducing their antibacterial properties.

Contents of the invention

In view of this, the object of the present invention is to provide an antibacterial ultrafiltration membrane, a preparation method thereof and a membrane regeneration method. The antibacterial ultrafiltration membrane provided by the present invention has excellent antibacterial properties.

The invention provides an antibacterial ultrafiltration membrane, which is prepared from an ultrafiltration membrane material having a repeating unit shown in formula I or formula II:

Preferably, the number average molecular weight of the ultrafiltration membrane material is 100,000 g/mol to 250,000 g/mol.

Preferably, the thickness of the antibacterial ultrafiltration membrane is 50-500 μm.

The present invention provides a kind of preparation method of antibacterial ultrafiltration membrane described in above-mentioned technical scheme, comprises the following steps:

The ultrafiltration membrane is prepared by a phase inversion method, and the materials used for the preparation of the ultrafiltration membrane include polyaryletherketone or polyarylethersulfone, and the polyaryletherketone has a repeating unit shown in formula III:

The polyarylethersulfone has a repeating unit represented by formula IV:

The ultrafiltration membrane is contacted with a chlorine solution to react to obtain an antibacterial ultrafiltration membrane.

Preferably, the chlorine-containing solution is selected from sodium hypochlorite solution and/or calcium hypochlorite-containing solution.

Preferably, the mass fraction of the sodium hypochlorite solution is 0.01-10%; the mass fraction of calcium hypochlorite in the calcium hypochlorite-containing solution is 0.1-30%.

Preferably, the solvent in the casting solution is selected from one or more of dimethylformamide, dimethylacetamide, methylpyrrolidone and dimethylsulfoxide.

Preferably, the reaction temperature is from 5°C to 35°C;

The reaction time is 5min-24h.

The invention provides a kind of regeneration method of antibacterial ultrafiltration membrane, comprises the following steps:

The antibacterial ultrafiltration membrane whose antibacterial performance has been reduced by 70% to 100% is contacted with a chlorine-containing solution to react to obtain a reproducible antibacterial ultrafiltration membrane;

The antibacterial ultrafiltration membrane is the antibacterial ultrafiltration membrane described in the above technical solution or the antibacterial ultrafiltration membrane prepared by the preparation method described in the above technical solution.

The invention provides an antibacterial ultrafiltration membrane prepared from an ultrafiltration membrane material having a repeating unit shown in formula I or formula II, wherein the repeating unit shown in formula I or formula II contains an N-Cl bond, The antibacterial ultrafiltration membrane prepared from the ultrafiltration membrane material having the repeating unit represented by the above formula I or formula II has higher bactericidal properties. In addition, the antibacterial ultrafiltration membrane has good filtration and separation performance; it can exist stably in air and water; it can be recycled; it is environmentally friendly and non-corrosive. Experimental result shows: antibacterial ultrafiltration membrane provided by the present invention has a bactericidal rate of 90% to 100% to Escherichia coli or Bacillus subtilis; 100%; the rejection rate of bovine serum albumin is above 99.2%.

Description of drawings

Fig. 1 is the antibacterial test figure of the antibacterial ultrafiltration membrane prepared by blank group 1, embodiment 1, 3 and 5;

Fig. 2 is the antibacterial property test diagram of the antibacterial ultrafiltration membrane prepared by blank group 2, embodiment 2, 4 and 6.

detailed description

The invention provides an antibacterial ultrafiltration membrane, which is prepared from an ultrafiltration membrane material having a repeating unit shown in formula I or formula II:

In the present invention, the number average molecular weight of the ultrafiltration membrane material is preferably 100,000 g/mol to 250,000 g/mol.

In the present invention, the thickness of the antibacterial ultrafiltration membrane is preferably 50-500 μm. In the present invention, the pure water flux of the antibacterial ultrafiltration membrane is 60-1000 L/m ² h; the rejection rate of the antibacterial ultrafiltration membrane to bovine serum albumin is above 99%.

The present invention provides a kind of preparation method of antibacterial ultrafiltration membrane described in above-mentioned technical scheme, comprises the following steps:

The ultrafiltration membrane is obtained by a phase inversion method, and the materials used to prepare the ultrafiltration membrane include polyarylether ketone or polyaryl ether sulfone, and the polyarylether ketone has a repeating unit shown in formula III:

The polyarylethersulfone has a repeating unit represented by formula IV:

The ultrafiltration membrane is contacted with a chlorine solution to react to obtain an antibacterial ultrafiltration membrane.

The preparation method provided by the invention has simple process, mild reaction conditions and low cost.

The present invention adopts a phase inversion method to obtain an ultrafiltration membrane, and the materials used to prepare the ultrafiltration membrane include polyarylether ketone or polyarylether sulfone, and the polyarylether ketone has a repeating unit represented by formula III:

The polyarylethersulfone has a repeating unit represented by formula IV:

In the present invention, the process of adopting the phase inversion method to obtain the ultrafiltration membrane preferably includes:

The casting solution is aged and film-formed in sequence to obtain an ultrafiltration membrane.

In a specific embodiment of the present invention, the preparation process of the casting solution is preferably prepared by the following method:

The polyarylether ketone having the repeating unit represented by formula III or the polyarylether sulfone having the repeating unit represented by formula IV is dissolved in a solvent, and then defoaming and aging are performed in sequence to obtain a casting solution.

In the present invention, the polyaryletherketone having the repeating unit represented by formula III is preferably according to the literature ZhonggangWang, Tianlu Chen, and Jiping Xu, Hydrogen-Bonding in Cardo Copoly(aryl etherketone)s and Its Effects on the Permeation Behavior, The preparation method described in Macromolecules 2007, 40, 3238-3245 was prepared. In the present invention, the number average molecular weight of the polyaryletherketone having the repeating unit represented by formula III is preferably 100,000 g/mol-250,000 g/mol.

In the present invention, the polyaryl ether sulfone having repeating units represented by formula IV is preferably according to the literature Qiang Zhang, Suobo Zhang, Weihui Bi, Synthesis and properties of amphiphilic poly(ethyleneoxide)-grafted cardo poly(aryl ether sulfone)copolymers , Polymer52 (2011), the preparation method described in 5471-5478 was prepared. In the present invention, the number average molecular weight of the polyarylethersulfone having repeating units represented by IV is preferably 100,000 g/mol to 250,000 g/mol.

In the present invention, the solvent is preferably selected from one or more of dimethylformamide, dimethylacetamide, methylpyrrolidone and dimethylsulfoxide.

The present invention has no special limitation on the method of defoaming and aging, and the technical solution of defoaming and aging well-known to those skilled in the art can be adopted. In the present invention, it is preferably aged in a constant temperature room at 28-32°C for 6-14 hours, more preferably at 30°C for 12 hours.

In the present invention, the mass fraction of the casting solution is preferably 12-30%, more preferably 15%-21%.

In the present invention, the casting solution is preferably formed into a film on a glass plate. In the present invention, a doctor blade well known to those skilled in the art is preferably used for film formation. In the present invention, the slit of the scraper is preferably 50-500 μm.

After the scraping membrane is completed in the present invention, it is preferably put into water immediately for phase inversion to obtain an ultrafiltration membrane. In the present invention, the phase inversion temperature is preferably 10°C to 50°C. In the present invention, the residual solvent in the obtained ultrafiltration membrane is preferably removed after the phase inversion is completed. In the present invention, deionized water is preferably used to remove the residual solvent. In a specific embodiment of the present invention, the present invention soaks the prepared ultrafiltration membrane in deionized water to remove residual solvent.

After the ultrafiltration membrane is obtained, the present invention contacts the ultrafiltration membrane with a chlorine-containing solution for a reaction to obtain an antibacterial ultrafiltration membrane.

In the present invention, the chlorine-containing solution is preferably selected from sodium hypochlorite solution and/or calcium hypochlorite-containing solution; the mass fraction of the sodium hypochlorite solution is preferably 0.01 to 10%, more preferably 1% to 8%; In a specific embodiment of the present invention, the mass fraction of the sodium hypochlorite solution is specifically 1%, 5% or 10%. In the present invention, the mass fraction of calcium hypochlorite in the solution containing calcium hypochlorite is preferably 0.1-30%, more preferably 1-25%; The calcium chlorate solution is specifically a bleaching powder solution; the mass fraction of calcium hypochlorite in the bleaching powder solution is 10%.

In the present invention, the reaction temperature is preferably 5°C-35°C, more preferably 15°C-25°C; the reaction time is preferably 5min-24h, more preferably 1h-2h.

The preparation method provided by the invention has simple process, mild reaction conditions and low cost.

The invention provides a kind of regeneration method of antibacterial ultrafiltration membrane, comprises the following steps:

The antibacterial ultrafiltration membrane whose antibacterial performance has been reduced by 70% to 100% is contacted with a chlorine-containing solution to react to obtain a reproducible antibacterial ultrafiltration membrane;

The antibacterial ultrafiltration membrane prepared by using the antibacterial ultrafiltration membrane described in the above technical solution or the preparation method described in the above technical solution.

In the present invention, the antibacterial ultrafiltration membrane with reduced antibacterial performance is based on the antibacterial ultrafiltration membrane before use. In the present invention, after the antibacterial ultrafiltration membrane is sterilized, the N-Cl bond in it is partially reduced to an N-H bond, the antibacterial performance is weakened, and the antibacterial ultrafiltration membrane is regenerated to obtain a regenerated antibacterial ultrafiltration membrane. The present invention adopts the chlorine-containing solution described in the above-mentioned technical scheme to contact with the sterilized antibacterial ultrafiltration membrane to react and obtain regeneration. The present invention has no special limitation on the bacteria in the use environment of the antibacterial ultrafiltration membrane. In the present invention, the bacteria are preferably Escherichia coli and/or Bacillus subtilis.

In order to further illustrate the present invention, a kind of antibacterial ultrafiltration membrane provided by the present invention and its preparation method and membrane regeneration method are described in detail below in conjunction with the examples, but they cannot be interpreted as limiting the protection scope of the present invention.

Example 1

1) Preparation of antibacterial ultrafiltration membrane:

Dissolve polyaryletherketone with a molecular weight of 200,000 g/mol in dimethylacetamide to form a polyaryletherketone solution with a mass fraction of 18%, fully dissolve it, filter to remove insoluble matter and defoam at 30°C Mature in a constant temperature room for 12 hours to obtain the casting solution; use a scraper to scrape the film on a clean glass plate with a slit of 150 μm, then immediately put the glass plate in deionized water for phase inversion, after the phase inversion is complete, soak in deionized water Remove residual solvent to obtain ultrafiltration membrane;

Soak the prepared ultrafiltration membrane in sodium hypochlorite solution (mass concentration 1%) for 5 min. Wash the residual sodium hypochlorite with water at 30°C, and constantly replace the water to remove a small amount of sodium hypochlorite remaining in the membrane to obtain an antibacterial ultrafiltration membrane.

2) Antibacterial performance experiment of antibacterial ultrafiltration membrane

In this experiment, Escherichia coli E.coli K12 (MG1655) was used to test the antibacterial performance of the antibacterial ultrafiltration membrane.

The medium formula used in the experiment is as follows:

LB liquid medium: 1% tryptone, 0.5% yeast extract, 1% sodium chloride, pH 7.0;

LB solid medium: 1% tryptone, 0.5% yeast extract, 1% sodium chloride, pH 7.0, 1.6% agar powder.

E.coli was inoculated in 5 mL of LB liquid medium, centrifuged at 37°C and 200 rpm for 12 hours, washed with phosphate buffered solution (PBS) and centrifuged three times to prepare a bacterial solution containing 10 ⁶ cells/mL. Take 20 μL and add it to the above-mentioned antibacterial ultrafiltration membrane of 2cm×2cm, then cover a piece of the same membrane above the membrane, press a sterile weight on it to make it fully contact for 30min; then soak the two pieces of membrane until the mass fraction of 5mL is Fully shake in 3% sodium thiosulfate solution for 20 minutes, take 100 μL after dilution and spread on LB solid medium. Take 20 μL of bacterial liquid (10 ⁶ cells/mL) and add it to 5 mL of sodium thiosulfate solution. After dilution, take 100 μL and spread it on LB solid medium as blank group 1. Incubate at 37°C for 24 hours, and the calculated bactericidal rate is 90%. The antibacterial test chart is shown in Figure 1. Fig. 1 is the antibacterial property test chart of the antibacterial ultrafiltration membrane prepared by blank group 1, embodiment 1, 3 and 5.

Soak the antibacterial ultrafiltration membrane in 10% sodium hypochlorite solution for 4 hours, take it out and wash it, the pure water flux before and after soaking in sodium hypochlorite solution is 244L/m ² h, 239L/m ² h, and the interception of 1g/L bovine serum albumin The rate remained basically unchanged at more than 99.8%.

Place the antibacterial ultrafiltration membrane in a laboratory under normal light conditions for 6 months, and use E.coli K12 (MG1655) to test the antibacterial performance of the membrane. Using the above antibacterial detection method, the calculated bactericidal rate is 90%.

Example 2

1) Preparation of antibacterial ultrafiltration membrane:

Dissolve polyaryletherketone with a molecular weight of 120,000 g/mol in dimethylacetamide to form a polyaryletherketone solution with a mass fraction of 15%, fully dissolve it, filter to remove insoluble matter and defoam at 30°C Mature in a constant temperature room for 12 hours to obtain a casting solution; use a scraper to scrape the film on a clean glass plate with a slit of 200 μm, and immediately put the glass plate in deionized water for phase inversion. After the phase inversion is complete, soak in deionized water Remove residual solvent to obtain ultrafiltration membrane;

Soak the prepared ultrafiltration membrane in sodium hypochlorite solution (mass concentration 5%) for 30min, wash the residual sodium hypochlorite with water at 30°C and soak in water for one day, and constantly replace the water to remove a small amount of sodium hypochlorite remaining in the membrane to obtain antibacterial ultrafiltration membrane.

2) Antibacterial performance experiment of antibacterial ultrafiltration membrane

In this experiment, Bacillus subtilis (CGMCC 1.1390) was used to test the antibacterial performance of the membrane.

Bacillus subtilis was inoculated in 5 mL of LB liquid medium, centrifuged at 37°C and 200 rpm for 12 hours, washed with phosphate buffered solution (PBS) and centrifuged three times to prepare a bacterial solution containing 10 ⁶ cells/mL. Take 20 μL and add it to the above-mentioned antibacterial ultrafiltration membrane of 2cm×2cm, then cover a piece of the same membrane above the membrane, press a sterile weight on it to make it fully contact for 30min; then soak the two pieces of membrane until the mass fraction of 5mL is Fully shake in 3% sodium thiosulfate solution for 20 minutes, take 100 μL after dilution and smear on LB solid medium, take 20 μL of bacterial solution (10 ⁶ cells/mL) and add it to 5 mL sodium thiosulfate solution, take 100 μL after dilution Smeared on the LB solid medium as blank group 2, cultured at 37°C for 24h, the calculated bactericidal rate was 90%, the antibacterial test chart is shown in Figure 2, and Figure 2 is the antibacterial ultrafiltration prepared by blank group 2, Examples 2, 4 and 6 The antimicrobial property test chart of the film. The prepared antibacterial ultrafiltration membrane was tested according to the above method, and the bactericidal rate was 95.2%. The antibacterial test chart is shown in Figure 2.

Soak the antibacterial ultrafiltration membrane in 10% sodium hypochlorite solution for 4 hours, take it out and wash it, the pure water flux before and after soaking in sodium hypochlorite solution is 625L/m ² h and 630L/m ² h respectively, and the interception of 1g/L bovine serum albumin The rate remained basically unchanged at more than 99.5%.

The antibacterial ultrafiltration membrane was placed in the laboratory under normal light conditions for 6 months, and the antibacterial performance of the antibacterial ultrafiltration membrane was tested by Bacillus subtilis (CGMCC 1.1390), and the calculated bactericidal rate was 94.9%.

Example 3

1) Preparation of antibacterial ultrafiltration membrane:

Dissolve polyaryletherketone with a molecular weight of 150,000 g/mol in dimethylacetamide to form a polyaryletherketone solution with a mass fraction of 15%, fully dissolve it, filter to remove insoluble matter and defoam at 30°C Mature in a constant temperature room for 12 hours to obtain a casting solution; use a scraper to scrape the film on a clean glass plate with a slit of 100 μm. Place the glass plate in deionized water immediately afterwards. After the phase inversion is complete, soak in deionized water to remove the residual solvent to obtain an ultrafiltration membrane;

Soak the prepared ultrafiltration membrane in bleaching powder solution (10% concentration) for 30min. Wash the residual sodium hypochlorite with water at 30°C and soak in water for one day, and change the water continuously to remove a small amount of sodium hypochlorite remaining in the membrane to obtain an antibacterial ultrafiltration membrane.

2) Antibacterial performance experiment of antibacterial ultrafiltration membrane

In this experiment, Escherichia coli E.coli K12 (MG1655) was used to test the antibacterial performance of the antibacterial ultrafiltration membrane. The prepared antibacterial ultrafiltration membrane was detected by the detection method of Example 1, and the bactericidal rate was 94.2%. The antibacterial test chart is shown in Figure 1.

Soak the antibacterial ultrafiltration membrane in 10% sodium hypochlorite solution for 4 hours, take it out and wash it, the pure water flux before and after soaking in sodium hypochlorite solution is 885L/m ² h, 876L/m ² h, and the interception of 1g/L bovine serum albumin The rate remained basically unchanged at above 99.2%.

The antibacterial ultrafiltration membrane was placed in the laboratory under normal light conditions for 6 months, and the antibacterial performance of the membrane was tested by E.coli K12 (MG1655). Using the above antibacterial detection method, the calculated bactericidal rate was 93.8%.

Example 4

1) Preparation of antibacterial ultrafiltration membrane:

Dissolve polyaryletherketone with a molecular weight of 200,000 g/mol in dimethylacetamide to form a polyaryletherketone solution with a mass fraction of 18%, fully dissolve it, filter to remove insoluble matter and defoam at 30°C Mature in a constant temperature room for 12 hours to obtain a casting solution. Use a scraper to scrape the film on a clean glass plate with a slit of 200 μm. Immediately put the glass plate in deionized water for phase inversion. After the phase inversion is complete, soak it in deionized water. Remove residual solvent to obtain ultrafiltration membrane;

Soak the prepared ultrafiltration membrane in bleaching powder solution (mass concentration: 10%) for 5 hours, wash the residual sodium hypochlorite with water at 30°C and soak in water for one day, and constantly replace the water to remove a small amount of sodium hypochlorite remaining in the membrane to obtain antibacterial ultrafiltration membrane.

2) Antibacterial performance experiment of antibacterial ultrafiltration membrane

In this experiment, Bacillus subtilis (CGMCC 1.1390) was used to test the antibacterial performance of antibacterial ultrafiltration membrane.

The prepared antibacterial ultrafiltration membrane was detected by the detection method of Example 2, and the bactericidal rate was 100%. The antibacterial test chart is shown in Figure 2.

Soak the antibacterial ultrafiltration membrane in 10% sodium hypochlorite solution for 4 hours, take it out and wash it, the pure water flux before and after soaking in sodium hypochlorite solution is 123L/m ² h, 125L/m ² h, and the interception of 1g/L bovine serum albumin The rate remained basically unchanged at more than 99.9%.

Place the antibacterial ultrafiltration membrane in a laboratory under normal light conditions for 6 months, and use Bacillus subtilis (CGMCC 1.1390) to test the antibacterial performance of the membrane. Using the above antibacterial detection method, the calculated bactericidal rate is 100%.

Example 5

1) Preparation of antibacterial ultrafiltration membrane:

Dissolve polyaryl ether sulfone with a molecular weight of 180,000 g/mol in dimethylacetamide to form a polyaryl ether sulfone solution with a mass fraction of 18%, fully dissolve it, filter to remove insoluble matter and defoam at 30°C Mature in a constant temperature room for 12 hours to obtain a casting solution. Use a scraper to scrape the film on a clean glass plate with a slit of 100 μm. Immediately put the glass plate in deionized water for phase inversion. After the phase inversion is complete, soak in deionized water Remove residual solvent to obtain ultrafiltration membrane;

Soak the prepared ultrafiltration membrane in a sodium hypochlorite solution (concentration 10%) for 2 hours, wash the residual sodium hypochlorite with water at 30° C., soak in water for one day, and constantly replace the water to remove a small amount of sodium hypochlorite remaining in the membrane to obtain an antibacterial ultrafiltration membrane.

2) Antibacterial performance experiment of antibacterial ultrafiltration membrane

In this experiment, Escherichia coli E.coli K12 (MG1655) was used to test the antibacterial performance of the antibacterial ultrafiltration membrane.

The prepared antibacterial ultrafiltration membrane was detected by the detection method of Example 1, and the bactericidal rate was 100%. The antibacterial test chart is shown in Figure 1.

Soak the antibacterial ultrafiltration membrane in 10% sodium hypochlorite solution for 4 hours, take it out and wash it, the pure water flux before and after soaking in sodium hypochlorite solution is 462L/m ² h, 460L/m ² h, and the interception of 1g/L bovine serum albumin The rate remained basically unchanged at more than 99.8%.

Place the antibacterial ultrafiltration membrane in a laboratory under normal light conditions for 6 months, and use E.coli K12 (MG1655) to test the antibacterial performance of the membrane. Using the above antibacterial detection method, the calculated bactericidal rate is 100%.

Example 6

1) Preparation of antibacterial ultrafiltration membrane:

Dissolve polyaryl ether sulfone with a molecular weight of 200,000 g/mol in dimethylacetamide to form a polyaryl ether sulfone solution with a mass fraction of 20%, fully dissolve it, filter to remove insoluble matter and defoam at 30°C Mature in a constant temperature room for 12 hours to obtain a casting solution. Use a scraper to scrape the film on a clean glass plate with a slit of 200 μm. Immediately put the glass plate in deionized water for phase inversion. After the phase inversion is complete, soak it in deionized water. Remove residual solvent to obtain ultrafiltration membrane;

Soak the prepared ultrafiltration membrane in bleaching powder solution (mass concentration 10%) for 2 hours, wash the residual bleaching powder with water at 30°C and soak in water for one day, and constantly replace the water to remove a small amount of sodium hypochlorite remaining in the membrane to obtain an antibacterial ultrafiltration membrane .

2) Antibacterial performance experiment of antibacterial ultrafiltration membrane

In this experiment, Bacillus subtilis (CGMCC 1.1390) was used to test the antibacterial performance of antibacterial ultrafiltration membrane.

The prepared antibacterial ultrafiltration membrane was detected by the detection method of Example 2, and the bactericidal rate was 100%. The antibacterial test chart is shown in Figure 2.

Soak the antibacterial ultrafiltration membrane in 10% sodium hypochlorite solution for 4 hours, take it out and wash it, the pure water flux before and after soaking in sodium hypochlorite solution is 88L/m ² h, 87L/m ² h, and the interception of 1g/L bovine serum albumin The rate remained largely unchanged at 100%.

Place the antibacterial ultrafiltration membrane in a laboratory under normal light conditions for 6 months, and use Bacillus subtilis (CGMCC 1.1390) to test the antibacterial performance of the membrane. Using the above antibacterial detection method, the calculated bactericidal rate is 100%.

Examples 7-12

The film after the sterilization of Examples 1 to 6, that is, the film treated with sodium thiosulfate, was washed and re-immersed in a sodium hypochlorite solution (5% mass concentration) for 2 hours, and soaked in water for one day after washing the residual sodium hypochlorite at 30° C., and constantly replaced the water. , to remove a small amount of sodium hypochlorite remaining in the membrane. Escherichia coli E.coli K12 (MG1655) was used to test the antibacterial performance of the film, and the prepared film was tested according to the detection method of Example 1, and the bactericidal rate was 100%.

As can be seen from the above examples, the present invention provides an antibacterial ultrafiltration membrane, which is prepared from an ultrafiltration membrane material having a repeating unit shown in formula I or formula II, and the repeating unit shown in formula I or formula II Including N-Cl bond, the antibacterial ultrafiltration membrane prepared by the ultrafiltration membrane material having the repeating unit shown in the above formula I or formula II has higher bactericidal properties. In addition, the antibacterial ultrafiltration membrane has good filtration and separation performance; it can exist stably in air and water; it can be recycled; it is environmentally friendly and non-corrosive. Experimental result shows: antibacterial ultrafiltration membrane provided by the present invention has a bactericidal rate of 90% to 100% to Escherichia coli or Bacillus subtilis; 100%; the rejection rate of bovine serum albumin is above 99.2%.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (6)

1. A kind of antibacterial ultrafiltration membrane, is prepared from by the ultrafiltration membrane material with the repeating unit shown in formula I or formula II: The number average molecular weight of the ultrafiltration membrane material is 100,000 g/mol to 250,000 g/mol; The thickness of the antibacterial ultrafiltration membrane is 50-500 μm. 2. a preparation method of the described antibacterial ultrafiltration membrane of claim 1, comprises the following steps: The ultrafiltration membrane is obtained by a phase inversion method, and the materials used to prepare the ultrafiltration membrane include polyarylether ketone or polyaryl ether sulfone, and the polyarylether ketone has a repeating unit shown in formula III: The polyarylethersulfone has a repeating unit represented by formula IV: The solvent in the casting solution used in preparing the ultrafiltration membrane is selected from one or more of dimethylformamide, dimethylacetamide, methylpyrrolidone and dimethyl sulfoxide; The ultrafiltration membrane is contacted with a chlorine solution to react to obtain an antibacterial ultrafiltration membrane. 3. The preparation method according to claim 2, characterized in that, the chlorine-containing solution is selected from sodium hypochlorite solution and/or a solution containing calcium hypochlorite. 4. preparation method according to claim 3 is characterized in that, the massfraction of described sodium hypochlorite solution is 0.01～10%; The massfraction of calcium hypochlorite in the described solution containing calcium hypochlorite is 0.1～30% %. 5. The preparation method according to claim 2, characterized in that, the reaction temperature is 5°C to 35°C; The reaction time is 5min-24h. 6. A regeneration method for an antibacterial ultrafiltration membrane, comprising the following steps: The antibacterial ultrafiltration membrane whose antibacterial performance has been reduced by 70% to 100% is contacted with a chlorine-containing solution to react to obtain a reproducible antibacterial ultrafiltration membrane; The antibacterial ultrafiltration membrane is the antibacterial ultrafiltration membrane according to claim 1 or the antibacterial ultrafiltration membrane prepared by the preparation method described in any one of claims 2-5.