CN108273398A - Antibacterial hollow fiber membrane and its preparation method and application - Google Patents

Abstract

The invention relates to the field of hollow fiber membrane preparation, in particular to an antibacterial hollow fiber membrane and a preparation method and application thereof. The method comprises the following steps: (1) in alkaline solution, activating the fiber mixed with the silver wires to obtain activated fiber; (2) mixing the activated fiber filaments with a membrane making solution, and weaving the obtained mixture to obtain a hollow fiber woven tube; (3) and forming the hollow fiber braided tube into an antibacterial hollow fiber membrane. The antibacterial hollow fiber membrane prepared by the method can keep high antibacterial performance for a long time, and the rupture pressure of the reinforced backwashing membrane of the antibacterial hollow fiber membrane is high in the preferred embodiment, so that the combination capacity of the support layer and the separation layer is high.

Description

Antibacterial hollow fiber membrane and its preparation method and application

technical field

The invention relates to the field of preparation of hollow fiber membranes, in particular to an antibacterial hollow fiber membrane and its preparation method and application.

Background technique

Membrane separation technology is widely used in the field of water treatment. Among them, polyvinylidene fluoride is a membrane material with excellent comprehensive properties. It has high tensile strength, excellent chemical stability, corrosion resistance and heat resistance, so it is often used in microfiltration, ultrafiltration and Materials for separation membranes such as nanofiltration. With the development of membrane technology, polyvinylidene fluoride has received more and more attention in the fields of wastewater treatment, biomedicine and food manufacturing.

However, due to the hydrophobicity of polyvinylidene fluoride, bacteria and other microorganisms are easy to adsorb and proliferate on the surface of the membrane during use, causing biological pollution, which will lead to a significant decrease in membrane flux, resulting in deterioration of membrane separation performance and production. Reduced water quality and shortened membrane life. Therefore, in the field of membrane separation, the prevention and control of biological pollution is particularly important. The current main methods include: continuously injecting chlorine gas into the water to be treated for sterilization, but it will pollute the quality of the influent water; or filter the water to be treated to remove Microorganisms, which makes the process more cumbersome; or during operation, oxidants such as sodium hypochlorite are added regularly and frequently to sterilize the membrane modules to kill microorganisms, but frequent chemical cleaning will damage the membrane structure and reduce the membrane. service life. Therefore, it is very important to prepare a separation membrane with its own antibacterial properties.

CN103933867A discloses a method for preparing a bacteriostatic PVC hollow fiber membrane. The method uses an ultrasonic method to disperse nano-silver particles in a membrane-forming liquid, and embeds the silver particles in the hollow fiber membrane during phase transformation to form a membrane. In addition, CN103285740A discloses a method for preparing an antibacterial double-layer hollow fiber membrane. In this method, silver ions are loaded into molecular sieves, and then doped into a membrane-making solution to prepare a hollow fiber membrane with silver-loaded molecular sieves enriched on the membrane surface. However, during the long-term operation of the film obtained by the above method, the fixation of silver as an antibacterial substance is not stable, so that the antibacterial substance will be continuously lost during the operation, resulting in the decline or even disappearance of the antibacterial performance of the film.

Contents of the invention

The object of the present invention is to provide an antibacterial hollow fiber membrane with long-lasting antibacterial performance and its preparation method and application.

As the first category invention of the present invention, as follows:

In order to achieve the above object, the present invention provides a method for preparing an antibacterial hollow fiber membrane on the one hand, the method comprising:

(1) In an alkaline solution, activate the fibers mixed with silver filaments to obtain activated fibers;

(2) mixing the activated fiber filaments with the membrane-making solution, and braiding the resulting mixture to obtain a hollow fiber braided tube;

(3) forming the hollow fiber braided tube into an antibacterial hollow fiber membrane;

Wherein, the film-forming solution contains a film-forming polymer, a porogen and additive A; the additive A is one or more of polyols and polypolyols with a number average molecular weight less than 1,000.

The second aspect of the present invention provides the antibacterial hollow fiber membrane prepared by the above method.

The third aspect of the present invention provides a membrane bioreactor comprising the above-mentioned antibacterial hollow fiber membrane.

The fourth aspect of the present invention provides the application of the above-mentioned antibacterial hollow fiber membrane in membrane separation.

By adopting the antibacterial hollow fiber membrane prepared by the method of the present invention, it can maintain high antibacterial performance for a long time, and in a preferred embodiment, the antibacterial hollow fiber membrane of the gained backwashing membrane rupture pressure is enhanced, It can be seen that the support layer and the separation layer have a strong binding ability; moreover, it can also have high water flux and high breaking strength, and is suitable for membrane bioreactors.

As the second type of invention of the present invention, it is as follows:

The first aspect of the second type of invention provides a method for modifying a hollow braided tube, comprising modifying the hollow braided tube with a modifying solution containing a polyphenol compound and a cross-linked polymer.

Preferably, the modified solution is prepared from a buffer solution, a polyphenol compound and a cross-linked polymer, more preferably, the buffer solution is selected from Tris buffer solution, PBS buffer solution or acetic acid/sodium acetate buffer solution.

Preferably, the polyphenolic compound is selected from at least one of catechol, tannic acid, dopamine, catechin, gallic acid and green tea extract, preferably catechol, tannic acid and dopamine At least one; the cross-linked polymer is selected from polyvinylamide, polyethylene glycol, polyvinylpyrrolidone, chitosan, polyethyleneimine, polyethylene polyamine, tetraethylenepentamine, diethylenetriamine, ethyl At least one of diamine and hexamethylenediamine, preferably at least one of polyethyleneimine, polyethylene glycol and diethylenetriamine; the hollow fiber tube is made of polyester fiber, polyamide fiber, polyolefin fiber, poly It is braided by at least one of amine fiber, polyurethane fiber, polysulfone fiber or glass fiber, preferably polyester fiber and/or polyamide fiber.

Preferably, in the modified solution, the concentration of the polyphenolic compound is 0.5wt%-15wt%, preferably 3wt%-15wt%; the concentration of the cross-linked polymer is 5wt%-20wt%, preferably 8wt%- 18 wt%.

Preferably, the temperature of the modification treatment is 40°C-80°C, preferably 50°C-70°C, and the time is 10 minutes-60 minutes.

The second aspect of the second type of invention provides a method for preparing a hollow fiber membrane, comprising:

Step A, using the above method to modify the hollow braided tube as the supporting material;

Step B, mineralizing the hollow braided tube treated in step A with a salt solution;

In step C, the surface of the hollow braided tube treated in step B is coated with a membrane-forming liquid.

Preferably, before step A, the hollow braided pipe is pretreated with lye, the lye is preferably selected from aqueous solutions of alkali metal hydroxides and alkaline earth metal hydroxides, and the concentration of the lye is preferably 5wt% -20 wt%.

Preferably, the salt solution is selected from at least one of CaCl solution, _FeCl solution, _CuCl solution and _{AgNO solution} , and the mass concentration of the salt solution is preferably 0.5%-5%, more preferably 1.5% -5%.

Preferably, the film-making liquid contains polyphenolic compounds, and the polyphenolic compounds are preferably selected from at least one of catechol, tannic acid, dopamine, catechin, gallic acid and green tea extract, and more It is preferably at least one selected from catechol, tannic acid and dopamine.

Preferably, the film-forming liquid also contains polyvinylidene fluoride, additives and solvents; preferably, in the film-forming liquid, the concentration of polyvinylidene fluoride is 8wt%-26wt%, more preferably 10wt%- 20wt%; the concentration of additives is 3wt%-17.5wt%, more preferably 3.5wt%-10wt%; the concentration of polyphenolic compounds is 3wt%-13wt%, more preferably 3.5wt%-10wt%.

Preferably, the additive is selected from at least one of polyvinylpyrrolidone with a molecular weight of 3000-50000, polyethylene glycol with a molecular weight of 1000-10000, polyethylene oxide with a molecular weight of 10000-60000 and polyvinyl alcohol with a molecular weight of 8000-50000 The solvent is at least one selected from N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone.

Preferably, in step B, the soaking temperature is 10-40°C, preferably 25-35°C; the soaking time is 1 hour-8 hours, preferably 3 hours-5 hours.

As the third category invention of the present invention, as follows:

The first aspect of the third type of invention of the present invention provides a method for preparing a hollow fiber membrane, comprising:

1) braiding silver-containing fiber bundles and polymer fiber bundles to obtain silver-containing fiber braided tubes;

2) Co-extrude the silver-containing fiber braided tube obtained in step 1) with the casting liquid and the core liquid, and then perform phase separation to obtain the hollow fiber membrane.

Preferably, the polymer fiber bundle is composed of 100-1000 fiber filaments; the silver-containing fiber bundle is composed of 1-10 silver-containing fiber filaments.

Preferably, the fiber filament is selected from at least one of polyester fiber, polyamide fiber, polyolefin fiber, polyamide fiber, polyurethane fiber, polysulfone fiber or glass fiber, preferably polyester fiber and/or polyamide fiber.

Preferably, the casting solution used in step 2) includes polyvinylidene fluoride, solvent, non-solvent and additives.

Preferably, the number average molecular weight of the polyvinylidene fluoride is 100,000-500,000; preferably, in the casting solution, the mass content of the polyvinylidene fluoride is 10%-30%, more preferably 15% %-25%.

Preferably, the additive is selected from at least one of polyvinylpyrrolidone with a molecular weight of 3000-50000, polyethylene glycol with a molecular weight of 1000-10000, polyethylene oxide with a molecular weight of 10000-60000 and polyvinyl alcohol with a molecular weight of 8000-50000 species; preferably, in the casting solution, the mass content of the additive is 2%-20%, more preferably 5%-15%.

Preferably, the solvent is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone; preferably, in the casting solution, The mass content of the solvent is 50%-80%, more preferably 60%-75%.

Preferably, the non-solvent is at least one of propylene glycol, glycerin, triethylene glycol and polyethylene glycol, and the polyethylene glycol is preferably selected from polyethylene glycol 200, polyethylene glycol 400 and polyethylene glycol At least one of diol 600; preferably, in the casting solution, the mass content of the non-solvent is 5%-20%, more preferably 8%-12%.

Preferably, the temperature of the coagulation bath is controlled at 30°C-80°C, preferably 50°C-70°C; the temperature of the core liquid is controlled at 20°C-80°C, preferably 20°C-60°C.

Preferably, after step 2), the hollow fiber membrane is subjected to post-hydrophilization treatment, the post-hydrophilization treatment is as follows: soak the hollow fiber membrane obtained in step 2) in water at 40°C-90°C for 2 hours -24 hours, carry out post-treatment of hydrophilization and membrane pore shaping; dry the hollow fiber membrane after hydrophilization at 20°C-60°C for 2 hours-48 hours, after drying, a high mechanical strength and antibacterial performance hollow fiber ultrafiltration membranes.

Description of drawings

Fig. 1 is a SEM image of the antibacterial hollow fiber membrane obtained in Example 1-1 of the first invention of the present invention.

Fig. 2 is a schematic diagram of a PVDF reinforced hollow fiber membrane with strong interfacial tension according to a preferred embodiment of the second invention of the present invention.

Fig. 3 is a structural view of the cross section of a hollow fiber membrane according to an embodiment of the second type of invention of the present invention.

Fig. 4 is a diagram showing the surface topography of a hollow fiber membrane according to an embodiment of the second type of invention of the present invention.

Fig. 5 is a schematic diagram of a hollow fiber membrane obtained according to a preparation method of an embodiment of the third invention of the present invention.

Fig. 6 is a scanning electron micrograph of a hollow fiber membrane obtained according to a preparation method of an embodiment of the third invention of the present invention soaked in an E. coli solution for 12 hours.

Detailed ways

Neither the endpoints nor any values of the ranges disclosed herein are limited to such precise ranges or values, and these ranges or values are understood to include values approaching these ranges or values. For numerical ranges, between the endpoints of each range, between the endpoints of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, these values Ranges should be considered as specifically disclosed herein.

In the first class of inventions of the present invention:

One aspect of the present invention provides a method for preparing an antibacterial hollow fiber membrane, the method comprising:

(1) In an alkaline solution, activate the fibers mixed with silver filaments to obtain activated fibers;

(2) mixing the activated fiber filaments with the membrane-making solution, and braiding the resulting mixture to obtain a hollow fiber braided tube;

(3) forming the hollow fiber braided tube into an antibacterial hollow fiber membrane;

Wherein, the film-forming solution contains a film-forming polymer, a porogen and additive A; the additive A is one or more of polyols and polypolyols with a number average molecular weight less than 1,000.

According to the present invention, the present invention can make the silver thread stably exist in the antibacterial hollow fiber membrane by combining the silver thread with the film-forming fiber thread and adopting the additive A in the film-making solution, thereby continuously exerting the antibacterial performance for a long time, Moreover, the strength of the obtained antibacterial hollow fiber membrane can also be enhanced at the same time.

Although the silver content in the silver-mixed fiber can vary within a wide range, considering the most effective combination of silver, it is preferable to use 100 fibers (film-forming fibers) , the number of said silver wires is 2-50, preferably 5-20.

Preferably, the fineness of the silver wire is 10-500D, preferably 50-300D, more preferably 100-200D. The silver wire can be produced by a conventional method in the art, or can be a commercial product, which is not particularly limited in the present invention.

Wherein, the fiber silk mixed with silver thread is preferably composed of the silver thread and film-forming fiber thread, and the film-forming fiber thread can be a hollow braided tube used to form a supporting layer when preparing a hollow fiber membrane conventional in the art. Silk of any fiber, for example, said film-forming fiber silk is one or more of polyester fiber, polyamide fiber, polyolefin fiber, polyamide fiber, polyurethane fiber, polyvinylidene fluoride fiber, polysulfone fiber and glass fiber kind. Considering that the film-forming fiber has a better cooperation with the silver wire and the film-making liquid used in the method of the present invention, thereby obtaining a more excellent antibacterial hollow fiber membrane, preferably, the fiber is Polyester and/or polyamide. The fiber filaments can be commercially available, or can be prepared by conventional methods in the art, which is not particularly limited in the present invention.

Wherein, preferably, the fineness of the film-forming fibers is 10-500D, preferably 50-300D, more preferably 100-200D. It is preferably a solid filament.

According to the present invention, in step (1), by performing activation treatment on the fibers mixed with silver threads in an alkaline solution, oil stains or surfactants etc. on the fibers mixed with silver threads can be removed, and it is also convenient to Fibers mixed with silver filaments are better for subsequent processing.

The basic compound in the basic solution can be any basic compound that realizes the activation effect on the fiber, preferably, the basic compound in the basic solution is an alkali metal hydroxide, an alkaline earth metal hydroxide , one or more of alkali metal carbonate, alkali metal bicarbonate and ammonia, more preferably sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, One or more of sodium bicarbonate, potassium bicarbonate and ammonia.

Wherein, the content of the basic compound in the basic solution can vary within a wide range, in order to obtain a better activation effect, preferably, the content of the basic compound in the basic solution is 5-20 wt. %, preferably 5-15% by weight.

According to the present invention, in step (1), the fiber filaments mixed with silver filaments can be partially, substantially completely or completely immersed in the alkaline solution, in order to enable the fiber filaments mixed with silver filaments to More comprehensive activation, preferably total immersion in the alkaline solution. Wherein, the consumption of described alkaline solution can change in wide range, as long as can make described fiber thread mixed with silver thread partly, substantially completely or completely soak wherein, the present invention does not have this special restrictions.

According to the present invention, preferably, the conditions of the activation treatment include: the temperature is 30-80° C., and the time is 10-50 minutes. More preferably, the conditions of the activation treatment include: the temperature is 30-70° C., and the time is 15-30 minutes.

According to the present invention, the step (1) may also include cleaning (for example, washing with water) the activated fiber filaments, and then centrifuging and drying (for example, centrifuging and drying at a speed of 3,000-10,000 rpm for 10-30 minutes), Thus, activated fiber filaments are obtained.

According to the present invention, the film-forming liquid contains a film-forming polymer, a pore-forming agent and an additive A to infiltrate the fiber filaments, and to form a separation layer during the film-forming process, which can enhance the bonding of the silver filaments in the resulting film stability.

Wherein, the film-forming polymer can adopt various conventional polymers used to form the separation layer in the art, but in order to increase the bonding performance with the fiber filaments obtained in step (1) of the present invention, preferably, the The film-forming polymer is one or more of polyvinylidene fluoride (PVDF), polyethersulfone (PES) and polyacrylonitrile (PAN). Preferably, the number average molecular weight of the film-forming polymer is 100,000-500,000.

Wherein, the porogen can be a conventional porogen used in the film-making solution in the art, such as polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), polyethylene oxide, polyvinyl alcohol , polymethyl methacrylate and polyvinyl acetate, preferably polyvinylpyrrolidone with a number average molecular weight of 3,000-50,000, polyethylene glycol with a molecular weight of 1,000-10,000, and polyepoxide with a molecular weight of 10,000-60,000 One or more of ethane, polyvinyl alcohol with a molecular weight of 8,000-50,000, and polymethyl methacrylate with a molecular weight of 11,000-85,000. The above molecular weights generally refer to number average molecular weights.

Among them, the additive A is preferably propylene glycol, glycerol, triethylene glycol, polyethylene glycol with a number average molecular weight of 200-800, polypropylene glycol with a number average molecular weight of 200-800, polyvinylpyrrolidone, polyvinyl alcohol One or more of butyraldehyde and polyvinyl acetate.

According to the present invention, although the film-forming solution contains the film-forming polymer, porogen and additive A, the antibacterial hollow fiber can be enhanced through the cooperation between the film-forming polymer, porogen and additive A. The performance of the film, but in order to improve the synergistic effect between the film-forming polymer, the porogen and the additive A, in order to make the film-making liquid have a stronger binding ability with the fiber filaments obtained in step (1), Preferably, in the film-forming solution, the weight ratio of the film-forming polymer, porogen and additive A is 100:15-70:20-150, preferably 100:20-60:30-100, more preferably Preferably it is 100:25-40:40-70.

According to the present invention, the solvent in the film-forming liquid is preferably a good solvent for the film-forming polymer and the porogen, preferably N,N'-dimethylformamide, N,N'-dimethylacetamide One or more of amide, N-methylpyrrolidone, triethyl phosphate, sulfolane, dimethyl sulfone and benzophenone. Wherein, preferably, the weight ratio of the film-forming polymer to the solvent is 1:2-8, preferably 1:3-6.

According to the present invention, preferably, the film-forming liquid also contains polyphenolic compounds, the polyphenolic compounds are compounds represented by formula (1), tannic acid, compounds represented by formula (2) and green tea extract one or more of these, among which,

At least 2 of R ¹ -R ⁶ are OH, and the rest are independently H, halogen, -L-COOM, -L-SO ₃ M, -L-NH ₂ , -L-OH, C1-C6 Alkyl, C1-C6 alkoxy or C1-C6 alkylthio; at least two of R ⁷ -R ¹⁰ and R ¹³ -R ¹⁷ are OH, and the remaining R ⁷ -R ¹⁰ and R ¹³ -R ¹⁷ and R ¹¹ -R ¹² are each independently H, halogen, -L-COOM, -L-SO ₃ M, -L-NH ₂ , -L-OH, C1-C6 alkyl, C1-C6 alkane Oxygen or C1-C6 alkylthio; each L is independently selected from C0-C6 alkylene; each M is independently H and an alkali metal element.

Wherein, specific examples of C1-C6 alkyl groups may be, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl and the like.

Specific examples of C1-C6 alkoxy can be, for example: methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, n-pentoxy base, n-hexyloxy group, etc.

Specific examples of C1-C6 alkylthio can be, for example: methylthio, ethylthio, n-propylthio, isopropylthio, n-butylthio, isobutylthio, tert-butylthio, n-pentylthio base, n-hexylthio group, etc.

The halogen can be, for example, F, Cl, Br, I.

The alkali metal elements may be, for example, Li, Na, K.

Specific examples of C0-C6 alkylene groups can be, for example: C0 alkylene groups, -CH ₂ -, -CH ₂ CH ₂ -, -CH ₂ CH ₂ CH ₂ -, -CH(CH ₃ )CH ₂ - , -CH ₂ CH(CH ₃ )-, -CH ₂ CH ₂ CH ₂ CH ₂ -, -CH(CH ₃ )CH ₂ CH ₂ -, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₂ CH ₃ )CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -, -CH ₂ C(CH ₃ ) ₂ -, -CH ₂ CH(CH ₂ CH ₃ )-, -CH ₂ CH ₂ CH(CH ₃ )-, -CH(CH ₂ CH ₃ CH ₃ )-, -CH(CH(CH ₃ )CH ₃ )-, -CH ₂ CH 2 CH ₂ CH _{2 CH 2 -} , -CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ -etc. Wherein, the alkylene group of C0 indicates that the linking group does not exist or indicates a linking bond, whereby the groups at both ends of the linking group are directly connected.

Preferably, at least two of R ¹ -R ⁶ are OH, and the rest are independently H, halogen, -L-COOM, -L-SO ₃ M, -L-NH ₂ , -L-OH, C1 -C4 alkyl, C1-C4 alkoxy or C1-C4 alkylthio; at least two of R ⁷ -R ¹⁰ and R ¹³ -R ¹⁷ are OH, and the remaining R ⁷ -R ¹⁰ and R ¹³ -R ¹⁷ and R ¹¹ -R ¹² are each independently H, halogen, -L-COOM, -L-SO ₃ M, -L-NH ₂ , -L-OH, C1-C4 alkyl, C1- C4 alkoxy group or C1-C4 alkylthio group; each L is independently selected from C0-C4 alkylene; each M is independently H, Na and K.

More preferably, at least two of R ¹ -R ⁶ are OH, and the rest are independently H, F, Cl, Br, -COOM, -CH ₂ -COOM, -CH ₂ CH ₂ -COOM, -CH ₂ CH ₂ CH ₂ -COOM, -CH(CH ₃ )CH ₂ -COOM, -CH ₂ CH(CH ₃ )-COOM, -CH ₂ CH ₂ CH ₂ CH ₂ -COOM, -SO ₃ M, -CH ₂ -SO ₃ M, -CH ₂ CH ₂ -SO ₃ M, -CH ₂ CH ₂ CH ₂ -SO ₃ M, -CH(CH ₃ )CH ₂ -SO ₃ M, -CH ₂ CH(CH ₃ )-SO ₃ M, -CH ₂ CH ₂ CH ₂ CH ₂ -SO ₃ M, -NH ₂ , -CH ₂ -NH ₂ , -CH ₂ CH ₂ -NH ₂ , -CH ₂ CH ₂ CH ₂ -NH ₂ , -CH (CH ₃ )CH ₂ -NH ₂ , -CH ₂ CH(CH ₃ )-NH ₂ , -CH ₂ CH 2 CH ₂ CH ₂ -NH ₂ , -OH, -CH _{2 -OH} , -CH ₂ CH ₂ - OH, -CH ₂ CH ₂ CH ₂ -OH, -CH(CH ₃ )CH ₂ -OH, -CH ₂ CH(CH ₃ )-OH, -CH ₂ CH ₂ CH ₂ CH ₂ -OH, methyl, ethyl base, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, iso Butoxy, sec-butoxy, tert-butoxy, methylthio, ethylthio, n-propylthio, isopropylthio, n-butylthio, isobutylthio, sec-butylthio or tert-butylthio base.

According to the present invention, in a preferred embodiment of the present invention, the compound shown in formula (1) is selected from the compounds shown in the following formula:

In a preferred embodiment of the present invention, the compound shown in formula (2) is selected from the compounds shown in the following formula:

Wherein, the green tea extract may be a green tea extract extracted by conventional extraction methods in the art, or may be a green tea extract product purchased from Hunan Lvman Biotechnology Co., Ltd.

Particularly preferably, the polyphenolic compound is one or more of gallic acid, catechol, tannic acid and dopamine, preferably gallic acid.

In a preferred embodiment of the present invention, the polyphenolic compound is gallic acid, the film-forming polymer is polyvinylidene fluoride, the porogen is polyvinylpyrrolidone, and the additive A is acrylic acid. Triols. More preferably, the film-forming polymer is polyvinylidene fluoride with a molecular weight of 200,000-210,000, and the porogen is polyvinylpyrrolidone with a number-average molecular weight of 25,000-30,000.

According to the present invention, preferably, in the film-forming solution, the weight ratio of the film-forming polymer to the polyphenol compound is 100:10-50, preferably 100:15-40.

According to the present invention, the dosage of the membrane-forming liquid can be the usual amount in the field, preferably so that the above-mentioned cellulose can be fully soaked with the membrane-forming liquid, which is not particularly limited in the present invention.

The preparation of the film-forming liquid can be carried out by using a conventional method for preparing a film-forming liquid in the art, for example, in an inert atmosphere (nitrogen atmosphere, argon atmosphere, etc.), the above-mentioned components can be stirred and mixed, and defoamed, so that Prepare membrane solution.

According to the present invention, the braiding can be carried out using conventional methods in the art, for example, introducing the mixture of the activated fiber filament and the film-making liquid into the braiding head of the braiding tube braider, and performing spinneret braiding through the braiding tube spinneret to form The braided tube is sent to the braided tube scraper to scrape off the excess film-making liquid adhered by the fiber filaments. After the braided tube is obtained, it enters the extrusion nozzle for co-extrusion under the pulling force of the wire-receiving wheel, wherein the pulling speed of the wire-receiving wheel is preferably 0.5-6m/min.

The method may further include: after step (2), subjecting the obtained hollow fiber braided tube to coagulation and water washing, wherein the temperature of the coagulation and water washing is preferably 30-80°C. The resulting hollow fiber braided tube can be formed into a membrane by coagulation and water washing treatments. Among them, the coagulation liquid used in the coagulation treatment can be water, or can be a liquid containing N,N'-dimethylformamide (DMF), N,N'-dimethylacetamide (DMAc), N-methyl An aqueous solvent (the water content is preferably 60% by weight or more) of one or more of pyrrolidone, triethyl phosphate, sulfolane, dimethyl sulfone and benzophenone. The coagulation and water washing treatment can be carried out simultaneously, that is, water washing is also carried out while coagulating in the coagulation liquid, of course, it can also be carried out step by step, for example, the fiber filaments after coagulation in the coagulation liquid are washed in water. Usually, coagulation and water washing are simultaneously performed directly in the coagulation solution in the coagulation tank.

According to the present invention, the process of forming the hollow fiber braided tube into an antibacterial hollow fiber membrane in step (3) can be carried out using the conventional method of the present invention, for example, it can be obtained by phase separation from the coagulation and washing treatment system. Antibacterial hollow fiber membrane.

According to the present invention, preferably, the step (3) further includes hydrophilizing the obtained antibacterial hollow fiber membrane, and the conditions of the hydrophilizing treatment include: soaking in hot water at 40-90° C. for 2-24 hours.

According to the present invention, after the hydrophilization treatment, the obtained membrane may also be washed (eg, washed with water), and dried (eg, dried at 20-60° C. for 2-48 hours).

The second aspect of the present invention provides the antibacterial hollow fiber membrane prepared by the above method.

The antibacterial hollow fiber membrane obtained in the present invention can maintain high antibacterial performance for a long time, and in a preferred embodiment, the antibacterial hollow fiber membrane of the gained backwashing membrane rupture pressure can be seen that its support layer and separation layer It has strong binding ability; moreover, it can also have high water flux, high breaking strength, high water contact angle, flux recovery rate, retention rate, etc., and is suitable for membrane bioreactors. Wherein, the bactericidal rate of the antibacterial hollow fiber membrane to Escherichia coli can still maintain more than 80%, preferably more than 85% after 240h, and the bactericidal rate to Staphylococcus aureus can still maintain more than 80%, preferably 83% after 250h above; backwash membrane rupture pressure, for example, can be above 2.5MPa, preferably 3-6MPa, more preferably 4-6MPa; water flux, for example, can be 150-250L/m ² h, preferably 150-200L/m ² h; The breaking strength may be above 15 MPa, preferably 18-22 MPa, more preferably 20-22 MPa; the water contact angle may be, for example, 50-60 degrees; the rejection rate may be, for example, above 90%.

The third aspect of the present invention provides a membrane bioreactor comprising the above-mentioned antibacterial hollow fiber membrane.

The fourth aspect of the present invention provides the application of the above-mentioned antibacterial hollow fiber membrane in membrane separation.

According to the present invention, the antibacterial hollow fiber membrane can be applied in the membrane separation technology involved in the fields of food, medicine, biology, environmental protection, chemical industry, metallurgy, energy, petroleum, water treatment, electronics and bionics.

In the second category of inventions of the present invention:

The second type of invention of the present invention is aimed at the situation that the hollow fiber membrane in the prior art is broken or broken due to reasons such as poor mechanical strength during the application process of the membrane bioreactor, and the membrane separation layer existing in the current reinforced hollow fiber membrane The invention provides a method for modifying a hollow braided tube and a method for preparing a hollow fiber layer due to the disadvantages of poor adhesion with the support material and easy falling off. On the one hand, the present invention constructs a transition layer with stable cross-linking and rough surface on the surface of the braided tube; on the other hand, the hollow fiber membrane with excellent interfacial strength is prepared by adjusting the components of the membrane-forming liquid.

In a first aspect of the present invention, there is provided a method for modifying a hollow braided tube, which includes modifying the hollow braided tube with a modification solution containing a polyphenol compound and a cross-linked polymer.

In the present invention, after the above-mentioned modification treatment, a modified coating is formed on the surface of the hollow braided pipe. The catechol groups in the modified coating form a hydrophobic interaction with the hollow braided tube, and the cross-linked structure strengthens the bonding strength and stability of the modified coating and the braided tube, and the surface of the modified coating introduces amino groups and hydroxyl groups, etc. The polar group is beneficial to improve the compatibility between the transition layer and the membrane material.

According to a preferred embodiment of the present invention, before the modification treatment, the hollow braided pipe is pretreated with lye. Preferably, the lye is selected from aqueous solutions of alkali metal hydroxides and alkaline earth metal hydroxides, more preferably aqueous solutions of sodium hydroxide, eg sodium hydroxide solution. In one embodiment, the concentration of the lye is 5wt%-20wt%. The pretreatment may be performed at a temperature of 20° C. to 60° C., for example, for 5 minutes to 60 minutes.

In one embodiment, the pretreatment of the hollow braided pipe with lye specifically includes: immersing the hollow braided pipe in a 5wt%-20wt% sodium hydroxide solution, and treating the hollow braided pipe at a temperature of 20°C-60°C for 5 minutes- 30 minutes, then wash with deionized water, centrifuge and dry at a speed of 3000-10000 rpm, and the treatment time is 5 minutes to 20 minutes.

According to a preferred embodiment of the present invention, the modification solution is prepared from a buffer solution, a polyphenol compound and a cross-linked polymer. Preferably, the buffer solution is selected from Tris buffer solution, PBS buffer solution or acetic acid/sodium acetate buffer solution.

According to a preferred embodiment of the present invention, the polyphenolic compound is selected from at least one of catechol, tannic acid, dopamine, catechin, gallic acid and green tea extract, preferably catechol, tannin at least one of acid and dopamine. Preferably, the concentration of the polyphenol compound is 0.5wt%-15wt%, preferably 3wt%-15wt%.

In one embodiment, the polyphenolic compound is catechol, preferably at a concentration of 5wt%-15wt%. In another embodiment, the polyphenolic compound is tannic acid, preferably at a concentration of 1wt%-10wt%. In yet another embodiment, the polyphenolic compound is dopamine, preferably at a concentration of 0.5wt%-8wt%.

According to a preferred embodiment of the present invention, the cross-linked polymer is selected from polyvinylamide, polyethylene glycol, polyvinylpyrrolidone, chitosan, polyethyleneimine, polyethylene polyamine, tetraethylenepentamine, diethylene At least one of triamine, ethylenediamine and hexamethylenediamine, preferably at least one of polyethyleneimine, polyethylene glycol and diethylenetriamine. Preferably, the concentration of the cross-linked polymer is 5wt%-20wt%, preferably 8wt%-18wt%.

According to a preferred embodiment of the present invention, the hollow fiber tube is made of at least one of polyester fiber, polyamide fiber, polyolefin fiber, polyamide fiber, polyurethane fiber, polysulfone fiber or glass fiber, preferably made of Woven in polyester and/or polyamide fibers.

In some embodiments, the inner diameter of the hollow braided tube is 0.7mm-1.5mm, and the outer diameter is 1.0mm-2.3mm. In some embodiments, the weaving density of the hollow braided tube is 15.5mm-17.5mm, and the grammage is 1.0g/mm-1.6g/mm.

According to a preferred embodiment of the present invention, the temperature of the modification treatment is 40-80° C., preferably 50-70° C., and the time is 10-60 minutes. In one embodiment, the modification treatment includes: mixing and stirring the polyphenolic compound, the cross-linked polymer and the buffer solution at room temperature, soaking the hollow braided tube into the modification solution, Treat for 10-60 minutes, then wash with deionized water, and spin dry by centrifugation.

In a second aspect of the present invention, a method for preparing a hollow fiber membrane is provided, comprising:

Step A, using the modification method described above to modify the hollow braided tube;

Step B, using a salt solution to mineralize the hollow braided tube treated in step A; and

In step C, the surface of the hollow braided tube treated in step B is coated with a membrane-forming solution.

In the method of the present invention, since the catechol group is reducible, nanoparticles can be grown on the surface of the braided tube through the mineralization treatment of the salt solution. On the one hand, the formation of nanoparticles further increases the interaction with the membrane separation layer, and on the other hand, the increase in roughness also further improves the binding sites, which is beneficial to the stability of the transition layer and the separation layer.

According to a preferred embodiment of the present invention, the salt solution is at least one selected from CaCl ₂ solution, FeCl ₃ solution, CuCl ₂ solution and AgNO ₃ solution. The mass concentration of the salt solution is 0.5%-5%, preferably 1.5%-5%.

According to a preferred embodiment of the present invention, the particle size of the nanoparticles is 15nm-32nm.

According to a preferred embodiment of the present invention, in step B, the soaking temperature is 10°C-40°C, preferably 25°C-35°C; the soaking time is 1 hour-8 hours, preferably 3 hours-5 hours.

Preferably, before performing step C, the hollow braided tube treated in step B is washed with deionized water and dried at a temperature of 60-80°C.

According to a preferred embodiment of the present invention, the number average molecular weight of the polyvinylidene fluoride in the casting solution is 100,000-500,000.

According to a preferred embodiment of the present invention, the film forming solution contains polyphenolic compounds. Preferably, the polyphenolic compound is selected from at least one of catechol, tannic acid, dopamine, catechin, gallic acid and green tea extract, more preferably catechol, tannic acid and dopamine at least one of .

According to a preferred embodiment of the present invention, the film forming solution further contains polyvinylidene fluoride, additives and solvents.

In the film forming solution, the concentration of polyvinylidene fluoride is preferably 8wt%-26wt%, more preferably 10wt%-20wt%.

In the film forming solution, the concentration of the additive is preferably 3wt%-17.5wt%, more preferably 3.5wt%-10wt%.

In the film forming solution, the concentration of polyphenolic compounds is preferably 3wt%-13wt%, more preferably 3.5wt%-10wt%.

According to a preferred embodiment of the present invention, the additive is polyvinylpyrrolidone with a molecular weight of 3000-50000, polyethylene glycol with a molecular weight of 1000-10000, polyethylene oxide with a molecular weight of 10000-60000 and polyvinyl alcohol with a molecular weight of 8000-50000 at least one of the

According to a preferred embodiment of the present invention, the solvent is at least one of N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone.

In the present invention, the polyphenol compound in the membrane-forming solution can effectively improve the adhesion of nanoparticles and polar groups on the separation layer and the transition layer.

In some embodiments, in step C, the hollow braided tube treated in step B is passed through the spinneret, and the film-making liquid is injected into the spinneret and kept at a constant pressure to pull the hollow braided tube at a fixed winding speed , so that the surface of the hollow braided tube is coated with the membrane-making liquid.

Preferably, the hollow braided tube coated with the membrane-making liquid is sequentially immersed in a gel tank and a water washing tank, so as to prepare the hollow fiber membrane. The hollow fiber membrane is a braided tube reinforced hollow fiber membrane with high adhesion strength.

Preferably, the spinneret hole diameter is 1.7mm-2.3mm. Preferably, the winding speed for pulling the hollow braided pipe is 2m/min-20m/min.

Preferably, the coagulation bath is a mixture of water and at least one of N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone, more preferably the quality of the water A score of 60% and above.

In the present invention, the operating temperature of the gel tank and the water washing tank is 30-80°C.

Preferably, the preparation method of the present invention further includes hydrophilizing the hollow fiber membrane prepared above, for example, soaking in hot water for 4 hours to 12 hours for hydrophilization treatment, and the temperature of the hot water is 60°C- 80°C.

Preferably, the hydrophilized hollow fiber membrane is washed with deionized water and dried at 20-60°C for 12-36 hours.

Compared with prior art, the beneficial effect of this second type invention of the present invention is:

1. The modification method of the polyphenol compound and the cross-linked polymer used in the present invention can realize the treatment on the surface of braided pipes of different materials, and the specific group and cross-linked structure in the coating ensure the stability of the modified coating . At the same time, the polar groups on the coating are modified to facilitate the adhesion of the polyvinylidene fluoride separation layer.

2. Realize the growth of various nanoparticles on the surface of the braided tube, the distribution of nanoparticles is uniform, and the size and density of nanoparticles can be adjusted by immersion time and solution temperature. The formation of nanoparticles effectively increases the interfacial contact area between the braided tube and the membrane separation layer, and enhances the interfacial bonding strength.

3. Silver nanoparticles can be introduced through the above method, and the braided tube reinforced hollow fiber membrane prepared by this method is endowed with excellent sterilization and sterilization properties, effectively prolonging the service time of the membrane.

4. Polyphenol compounds are added to the membrane-making solution to further enhance the combination of the separation layer and the transition layer, ensuring the long-term stable operation of the hollow membrane.

5. The preparation process of the present invention is simple, and the raw materials used are cheap, which is beneficial to industrial production.

In the third category of inventions of the present invention:

The third type of invention of the present invention, in order to solve the above technical problems, the present invention provides a new method for preparing hollow fiber membranes. Described preparation method comprises:

1) braiding silver-containing fiber bundles and polymer fiber bundles to obtain silver-containing fiber braided tubes;

2) Co-extrude the silver-containing fiber braided tube obtained in step 1) with the casting liquid and the core liquid, and then perform phase separation to obtain the hollow fiber membrane.

According to a preferred embodiment of the present invention, the preparation method further includes cleaning the silver-containing fibers and/or polymer fibers before step 1). According to one embodiment, the silver-containing fibers and/or polymer fibers are washed with lye and deionized water. Preferably, the lye is 5%-15% sodium hydroxide solution. Preferably, the temperature of washing with lye is 20 minutes to 60 minutes, and the time is 5 minutes to 30 minutes.

According to a preferred embodiment of the present invention, the preparation method further includes post-hydrophilizing the hollow fiber membrane after step 2). According to a preferred embodiment, the hydrophilization post-treatment is as follows: soak the hollow fiber membrane obtained in step 2) in water at 40°C-90°C for 2 hours-24 hours to perform post-treatment of hydrophilization and membrane pore shaping; The hollow fiber membrane after hydrophilic treatment is dried at 20°C-60°C for 2 hours-48 hours, and after drying, a hollow fiber ultrafiltration membrane with high mechanical strength and antibacterial performance is obtained.

According to a preferred embodiment of the present invention, the weaving is: the silver-containing fiber bundle and the polymer fiber bundle are cross-braided in a "herringbone" shape along the core liquid tube.

Preferably, the polymer fiber bundle is composed of 100-1000 fiber filaments. Preferably, the silver-containing fiber bundle is composed of 1-10 silver-containing fiber filaments.

According to the present invention, the silver-containing fiber bundles can be obtained commercially or by self-made.

According to a preferred embodiment of the present invention, the fiber filaments are selected from at least one of polyester fibers, polyamide fibers, polyolefin fibers, polyamide fibers, polyurethane fibers, polysulfone fibers or glass fibers, preferably polyester fibers and/or or polyamide fibers.

According to a preferred embodiment of the present invention, the casting solution used in step 2) includes polyvinylidene fluoride, solvent, non-solvent and additives.

According to a preferred embodiment of the present invention, the casting solution is prepared by the following steps: mixing polyvinylidene fluoride, solvent, non-solvent, and additives, stirring in a reaction kettle at 60°C-120°C for 12 hours-24 hours, Vacuum defoaming for 12-24 hours to obtain the casting solution.

Preferably, the number average molecular weight of the polyvinylidene fluoride is 100,000-500,000. In the casting solution, the mass content of the polyvinylidene fluoride is preferably 10%-30%, more preferably 15%-25%.

Preferably, the additive is selected from at least one of polyvinylpyrrolidone with a molecular weight of 3000-50000, polyethylene glycol with a molecular weight of 1000-10000, polyethylene oxide with a molecular weight of 10000-60000 and polyvinyl alcohol with a molecular weight of 8000-50000 kind. In the casting solution, the mass content of the additive is preferably 2%-20%, more preferably 5%-15%.

Preferably, the solvent is at least one selected from N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone. In the casting solution, the mass content of the solvent is preferably 50%-80%, more preferably 60%-75%.

Preferably, the non-solvent is at least one of propylene glycol, glycerol, triethylene glycol and polyethylene glycol. The polyethylene glycol is preferably selected from polyethylene glycol 200, polyethylene glycol 400 and polyethylene glycol 600. In the casting solution, the mass content of the non-solvent is preferably 5%-20%, more preferably 8%-12%.

According to a preferred embodiment of the present invention, the core liquid is a mixed solution of the solvent, or a mixed solvent of water and the non-solvent. Preferably, in the core liquid, the weight percent concentration of water is 50%-100%, preferably 70%-100%.

According to a preferred embodiment of the present invention, the temperature of the core fluid is controlled at 20°C-80°C, preferably 20°C-60°C

According to a preferred embodiment of the present invention, said phase separation is carried out by immersing the coextruded product in a coagulation bath and a water bath. The coagulation bath is an aqueous solution of at least one of N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone, and the mass concentration is preferably 0%-40%, more preferably 0%-20%.

According to a preferred embodiment of the present invention, the temperature of the coagulation bath is controlled at 30°C-80°C, preferably 50°C-70°C.

Compared with prior art, the beneficial effect of the present invention is:

1. Using the fiber weaving-coextrusion integrated process, the silver-containing fiber bundles and polymer fibers are woven into a fiber braided reinforcement layer, which is embedded in the body of the hollow fiber membrane. Compared with ordinary hollow fiber membranes, the membrane has a higher tensile strength of 12.5MPa-50MPa, an anti-burst strength of 0.25MPa-1.5MPa, and a pure water flux of 120L/m ² h-500L/m ² h .

2. The hollow fiber membrane obtained by the present invention has excellent antibacterial and bactericidal effects due to the introduction of the silver-containing braided tube. Experiments show that the hollow fiber membrane has an inhibitory rate of 82.5%-93.5% to Escherichia coli and a 75.1%-89.7% inhibitory rate to Staphylococcus aureus, and has excellent antibacterial effect. At the same time, the rejection rate of the hollow fiber membrane to bovine serum albumin is 95.3%-97.3%, and has excellent separation performance.

3. Since the silver-containing braided tube used in the present invention is wrapped in the polyvinylidene fluoride hollow membrane, the silver particles are not easy to elute during use and have a long antibacterial time.

4. The present invention provides a method for preparing the above-mentioned hollow fiber ultrafiltration membrane with antibacterial and high mechanical strength. The method is simple to operate and can be realized by using existing industrial equipment, which is beneficial to realize industrial production.

It should be understood that although the above three types of inventions of the present invention have similar content, the descriptions of these three types of inventions are independent of each other and do not limit each other.

The present invention will be described in detail below by way of examples.

The following examples are provided for the first category of inventions of the present invention:

In the following examples and comparative examples:

The water flux is measured by a dead-end external pressure filtration device, that is, the wet membrane after cleaning is pre-pressed at 0.15MPa for 30 minutes, and then the external pressure water flux is measured at 0.1MPa; then BSA solution is passed through to measure the retention rate.

The backwash membrane rupture pressure reflects the interfacial bonding strength between the braided pipe and the separation layer, which is measured by water backwash pressure.

The water contact angle was measured by a contact angle meter.

The model bacteria used in the antibacterial test were Escherichia coli and Staphylococcus aureus, which were purchased from Shanghai Enzyme Biotechnology Co., Ltd.

Antibacterial performance test method: the antibacterial performance of the film in each embodiment to the above two bacteria was measured by the zone of inhibition method. The operation is as follows: on an ultra-clean workbench, draw 100 μL of Escherichia coli or Staphylococcus aureus suspension and mix it with 15 mL of medium, pour it into a petri dish and cool it to form a flat plate containing bacteria, and then sterilize the membrane of the embodiment through moist heat Then spread on the surface of the culture medium and cultivate at 37°C. During the culture period, observe and calculate the bactericidal rate of Escherichia coli and Staphylococcus aureus at intervals of 24h, 72h, 144h and 240h respectively.

Membrane solution preparation example 1-9

Under the protection of nitrogen, according to the composition in Table 1 (the type of each compound and the concentration in the membrane-forming solution are as listed, wherein, the concentration refers to the percentage of the net mass of each compound accounting for the total weight of the membrane-forming solution), each group Stir and mix under specified conditions (conditions are shown in Table 1) to dissolve, then vacuum degassing to obtain the corresponding film-making solution; in Table 1:

PVDF is polyvinylidene fluoride purchased from Arkema MG15 brand, and its number average molecular weight is 210,000;

PVP is polyvinylpyrrolidone purchased from Sinopharm Reagent Co., Ltd. K30 brand, and its number average molecular weight is 30,000;

PEG20,000 is polyethylene glycol purchased from Sinopharm Reagent Co., Ltd., and its number average molecular weight is 20,000;

PEG400 is polyethylene glycol purchased from Sinopharm Reagent Co., Ltd., and its number average molecular weight is 400;

PEG600 is polyethylene glycol purchased from Sinopharm Reagent Co., Ltd., with a number average molecular weight of 600;

Polyethylene oxide was purchased from Sinopharm Reagent Co., Ltd., and its number average molecular weight was 40,000.

PES is polyethersulfone purchased from Sinopharm Reagent Co., Ltd., and its number average molecular weight is 100 000;

PAN is polyacrylonitrile purchased from Sinopharm Reagent Co., Ltd., with a number average molecular weight of 80,000.

Membrane solution preparation comparative example 1

According to the preparation process of membrane-forming solution B2, the difference is that dopamine and glycerol are not used, and the amount of PVDF is increased to 22% by weight, and the amount of PVP is increased to 12% by weight, thereby producing membrane-forming solution DB1.

Membrane solution preparation comparative example 2

According to the preparation process of membrane-forming solution B2, the difference is that dopamine and PVP are not used, and the amount of PVDF is increased to 22% by weight, and the amount of glycerol is increased to 12% by weight, thereby producing membrane-forming solution DB2.

Table 1

Example 1-1

This example is used to illustrate the antibacterial hollow fiber membrane of the present invention and its preparation method.

(1) immerse 200 long filament polyester filaments (solid filaments with a fineness of 50D) and 5 silver threads (with a fineness of 50D) in 5% by weight of sodium hydroxide solution, and heat at 60°C After activation for 30 min, the separated fibers were washed with deionized water, and centrifuged at 3000 rpm for 30 min to spin dry.

(2) Soak the activated fiber filaments obtained in step (1) in the film-making solution B1 for 1 min, and send the resulting mixture into the braiding head of the braiding tube braider for braiding. The tube enters the braided tube scraper to scrape off the excess film-making liquid adhering to the fiber filaments. Under the traction of the friction wheel, it enters the extrusion nozzle at a forward speed of 4m/min for co-extrusion. Then enter into a coagulation bath (namely water) at 60°C to obtain an antibacterial hollow fiber membrane.

(3) Soak the antibacterial hollow fiber membrane obtained in step (2) in water at 60° C. for 12 hours to perform hydrophilic treatment; wash the treated fiber membrane with deionized water, and dry at 30° C. for 24 hours. The antibacterial hollow fiber membrane M1 was thus obtained, and its SEM image is shown in FIG. 1 .

The properties of the film are shown in Tables 2 and 3.

Example 1-2

This example is used to illustrate the antibacterial hollow fiber membrane of the present invention and its preparation method.

According to the method described in embodiment 1-1, the difference is:

Step (1): what adopt is 100 filament nylon fibers (the fineness is the solid filament of 150D) and 10 silver threads (the fineness is 150D); Alkaline solution is the potassium hydroxide solution of 7.5% by weight, activation condition: The temperature is 50°C, and the time is 25 minutes; the centrifugation conditions are: the speed is 5000 rpm, and the time is 25 minutes;

Step (2): Soak the activated fiber filaments obtained in step (1) in film-making solution B2 for 2 minutes; the pulling speed is 3m/min;

Step (3): hydrophilization treatment conditions: the temperature is 70° C., and the time is 12 hours. Thus, the antimicrobial hollow fiber membrane M2 was obtained.

The properties of the film are shown in Tables 2 and 3.

Example 1-3

This example is used to illustrate the antibacterial hollow fiber membrane of the present invention and its preparation method.

According to the method described in embodiment 1-1, the difference is:

Step (1): 150 filament nylon fibers (solid filaments with a fineness of 100D) and 8 silver threads (a fineness of 100D) are used for the fiber filaments; the alkaline solution is 10% by weight of sodium hydroxide solution, and the activation conditions are: The temperature is 50°C, and the time is 30 minutes; the centrifugation conditions are: the speed is 5000 rpm, and the time is 25 minutes;

Step (2): Soak the activated fiber filaments obtained in step (1) in the film-making solution B3 for 3 minutes; the pulling speed is 3m/min; the coagulation bath is a mixture of DMAc and H ₂ O with a weight ratio of 1:4 ( temperature is 60°C);

Step (3): Hydrophilic treatment conditions: the temperature is 60° C., and the time is 6 hours; the drying condition is 25° C. for 24 hours. Thus, an antimicrobial hollow fiber membrane M3 was obtained.

The properties of the film are shown in Tables 2 and 3.

Example 1-4

This example is used to illustrate the antibacterial hollow fiber membrane of the present invention and its preparation method.

According to the method described in embodiment 1-1, the difference is:

Step (2): Using membrane-making solution B4 instead of membrane-making solution B1;

Thus, an antimicrobial hollow fiber membrane M4 was obtained.

The properties of the film are shown in Tables 2 and 3.

Example 1-5

This example is used to illustrate the antibacterial hollow fiber membrane of the present invention and its preparation method.

According to the method described in embodiment 1-1, the difference is:

Step (1): fiber thread adopts 100 filament nylon fibers (solid filaments of 250D in fineness) and 10 silver threads (250D in fineness); alkaline solution is 8% by weight of sodium carbonate solution, activation condition: temperature The temperature is 60°C, and the time is 15 minutes; the centrifugation conditions are: the speed is 10,000 rpm, and the time is 15 minutes;

Step (2): Soak the activated fiber filaments obtained in step (1) in film-making solution B5 for 5 minutes; the pulling speed is 1.5m/min;

Step (3): Hydrophilic treatment conditions: the temperature is 60° C., and the time is 6 hours; the drying condition is 25° C. for 24 hours. Thus, an antimicrobial hollow fiber membrane M5 was obtained.

The properties of the film are shown in Tables 2 and 3.

Examples 1-6

This example is used to illustrate the antibacterial hollow fiber membrane of the present invention and its preparation method.

According to the method described in embodiment 1-1, the difference is:

Step (1): fiber thread adopts 80 filament nylon fibers (solid filaments with a fineness of 300D) and 8 silver threads (with a fineness of 300D); the alkaline solution is 10% by weight of potassium carbonate solution, and the activation condition: temperature The temperature is 60°C, and the time is 15 minutes; the centrifugation conditions are: the speed is 10,000 rpm, and the time is 15 minutes;

Step (2): Soak the activated fiber filaments obtained in step (1) in film-making solution B1 for 3 minutes; the pulling speed is 3 m/min; the temperature of the water used as the coagulation bath is 65° C.;

Step (3): The drying condition is 25° C. for 24 hours. Thus, an antimicrobial hollow fiber membrane M6 was obtained.

The properties of the film are shown in Tables 2 and 3.

Example 1-7

This example is used to illustrate the antibacterial hollow fiber membrane of the present invention and its preparation method.

According to the method described in embodiment 1-1, the difference is that in step (1), 200 glass fiber filaments (solid filaments with a fineness of 300D) are used to replace filament polyester filaments;

After passing through the various steps, the antibacterial hollow fiber membrane M7 is thus obtained.

The properties of the film are shown in Tables 2 and 3.

Examples 1-8

This example is used to illustrate the antibacterial hollow fiber membrane of the present invention and its preparation method.

According to the method described in embodiment 1-1, the difference is:

Step (4): The film-making solution used is film-making solution B6;

After passing through the various steps, the antibacterial hollow fiber membrane M8 is thus obtained.

The properties of the film are shown in Tables 2 and 3.

Examples 1-9

This example is used to illustrate the antibacterial hollow fiber membrane of the present invention and its preparation method.

According to the method described in embodiment 1-1, the difference is:

Step (4): The film-making solution used is film-making solution B7;

After passing through the various steps, the antibacterial hollow fiber membrane M9 is thus obtained.

The properties of the film are shown in Tables 2 and 3.

Examples 1-10

This example is used to illustrate the antibacterial hollow fiber membrane of the present invention and its preparation method.

According to the method described in embodiment 1-1, the difference is:

Step (4): The film-making solution used is film-making solution B8;

After passing through each step, the antimicrobial hollow fiber membrane M10 is thus obtained.

The properties of the film are shown in Tables 2 and 3.

Examples 1-11

This example is used to illustrate the antibacterial hollow fiber membrane of the present invention and its preparation method.

According to the method described in embodiment 1-1, the difference is:

Step (4): The film-making solution used is film-making solution B9;

After passing through each step, the antibacterial hollow fiber membrane M11 is thus obtained.

The properties of the film are shown in Tables 2 and 3.

Comparative example 1-1

According to the method described in embodiment 1-1, the difference is:

Step (2): The film-making solution used is film-making solution DB1;

After passing through each step, the antibacterial type hollow fiber membrane DM1 is thus obtained.

The properties of the film are shown in Tables 2 and 3.

Comparative example 1-2

According to the method described in embodiment 1-1, the difference is:

Step (2): the film-making liquid used is film-making liquid DB2;

After passing through each step, the antibacterial hollow fiber membrane DM2 is thus obtained.

The properties of the film are shown in Tables 2 and 3.

Comparative example 1-3

According to the method described in embodiment 1-1, the difference is that step (1) does not use silver wire, but directly activates the filament polyester fiber;

After passing through the respective steps, the hollow fiber membrane DM3 is thus obtained.

The properties of the film are shown in Tables 2 and 3.

Table 2

table 3

From the results in Tables 2 and 3, it can be seen that the antibacterial hollow fiber membrane of the present invention has large water flux, high retention rate, and better bactericidal effect on Escherichia coli and Staphylococcus aureus.

The following examples are provided for the second category of inventions of the present invention:

Example 2-1

1) Immerse a polyester fiber hollow braided tube with an inner diameter of 1.0mm and an outer diameter of 1.7mm in a 5wt% sodium hydroxide solution, treat it at 50°C for 30min, and then wash it with deionized water at a speed of 3000 rpm Centrifuge for 5 minutes and dry at 80°C.

2) configure a Tris buffer solution with pH 8.5, mix it uniformly with dopamine and polyethyleneimine, and prepare a modified solution whose dopamine concentration is 4.0wt% and polyethyleneimine concentration is 10wt%; The tube was dipped into the modification solution for one coating, treated at 60° C. for 30 minutes, washed with deionized water, and dried by centrifugation.

3) Soak the braided tube after the above treatment in 2% CaCl ₂ solution for mineralization, and treat it at room temperature (25°C) for 8h to grow nanoparticles (25.6±3.6nm) on the surface of the braided tube; wash with deionized water Afterwards, dry at a temperature of 60°C.

4) Under the condition of nitrogen protection, blend polyvinylidene fluoride, additives, dopamine and solvent, stir at 80°C for 24 hours, and vacuum defoam to obtain the casting solution. The components and concentrations of the casting solution are as follows:

The number average molecular weight of polyvinylidene fluoride is 2.1×10 ⁵ , and the weight percent concentration is 10%;

The additive is polyvinylpyrrolidone, the number average molecular weight is 30000, and the weight percent concentration is 8.0%;

The weight percent concentration of dopamine is 6%;

The solvent is N,N-dimethylacetamide, and the weight percent concentration is 76%.

5) Coat the mineralized braided pipe twice with the casting solution, and enter it into a coagulation bath at 40°C to obtain a polyvinylidene fluoride hollow fiber composite microporous membrane. The air temperature is 30°C and the relative humidity is 75%. The distance of the air section is 10cm.

The coagulation bath is water.

6) Soak the polyvinylidene fluoride hollow fiber composite microporous membrane in hot water for 6 hours for hydrophilization treatment. The temperature of the hot water is 80° C.; then wash with deionized water and dry at 30° C. for 24 hours. A braided tube-reinforced polyvinylidene fluoride hollow fiber membrane with high bonding strength was obtained.

Example 2-2

1) Immerse a nylon fiber braided tube with an inner diameter of 1.0mm and an outer diameter of 1.7mm in 7.5wt% sodium hydroxide solution, treat it at 45°C for 20min, then wash it with deionized water, and centrifuge at a speed of 5000 rpm 10min, dry at 80°C.

2) Configure a Tris buffer solution with a pH of 8.5, uniformly mix it with dopamine and diethylenetriamine to prepare a modified solution with a dopamine concentration of 8.0wt% and a diethylenetriamine concentration of 15wt%; Immerse in the modification solution for one coating, treat at 70° C. for 20 minutes, wash with deionized water, and spin dry by centrifugation.

3) Soak the braided tube after the above treatment in 3wt% _AgNO solution for mineralization, and treat it at room temperature (25°C) for 7h to grow nanoparticles (16.4±2.6nm) on the surface of the braided tube; wash with deionized water Finally, dry at a temperature of 70°C.

4) Under the condition of nitrogen protection, blend polyvinylidene fluoride, additives, dopamine and solvent, stir at 80°C for 24 hours, and vacuum defoam to obtain the casting solution. The components and concentrations of the casting solution are as follows:

The number average molecular weight of polyvinylidene fluoride is 2.1×10 ⁵ , and the weight percent concentration is 15%;

The additive is polyvinylpyrrolidone (PVP), with a number average molecular weight of 30,000 and a concentration of 5.5% by weight;

The weight percentage concentration of dopamine is 3.5%;

The solvent is N,N-dimethylacetamide, and the weight percent concentration is 86%.

5) Coat the mineralized braided pipe twice with the casting solution, and enter it into a coagulation bath at 40°C to obtain a polyvinylidene fluoride hollow fiber composite microporous membrane. The air temperature is 30°C and the relative humidity is 75%. The distance of the air section is 10cm.

The coagulation bath is water.

6) Soak the polyvinylidene fluoride hollow fiber composite microporous membrane in hot water for 12 hours for hydrophilization treatment. The temperature of the hot water is 80° C.; then wash with deionized water and dry at 30° C. for 24 hours. A braided tube-reinforced polyvinylidene fluoride hollow fiber membrane with high bonding strength was obtained.

Example 2-3

1) Immerse a nylon fiber hollow braided tube with an inner diameter of 1.0mm and an outer diameter of 1.7mm in a 10wt% sodium hydroxide solution, treat it at a temperature of 50°C for 15min, then wash it with deionized water, and centrifuge at a speed of 8000 rpm 10min, dry at 80°C.

2) configure the Tris buffer solution with pH 8.5, uniformly mix it with tannic acid and diethylenetriamine to obtain a modified solution whose concentration of tannic acid is 5wt% and diethylenetriamine concentration is 10wt%; The finished braided tube was dipped into the modification solution for one coating, treated at 60° C. for 40 minutes, washed with deionized water, and dried by centrifugation.

3) Soak the braided tube after the above treatment in 5wt% _FeCl solution for mineralization, and treat it at room temperature (25°C) for 6h to grow nanoparticles (13.8±2.2nm) on the surface of the braided tube; wash with deionized water Afterwards, dry at a temperature of 60°C.

4) Under the condition of nitrogen protection, blend polyvinylidene fluoride, PEG, tannic acid and N,N-dimethylacetamide, stir at 80°C for 18 hours, and vacuum defoam to obtain casting solution. The components and their concentrations are as follows:

The number average molecular weight of polyvinylidene fluoride is 2.1×10 ⁵ , and the weight percent concentration is 10%;

The number average molecular weight of PEG is 20,000, and the weight percent concentration is 4.5%;

The weight percent concentration of tannic acid is 4%;

The weight percent concentration of N,N-dimethylacetamide is 81.5%.

5) Coat the mineralized braided pipe twice with the casting solution, and enter it into a coagulation bath at 40°C to obtain a polyvinylidene fluoride hollow fiber composite microporous membrane. The air temperature is 30°C and the relative humidity is 75%. The distance of the air section is 10cm.

The coagulation bath is water.

6) Soak the polyvinylidene fluoride hollow fiber composite microporous membrane in hot water for 10 hours for hydrophilization treatment. The temperature of the hot water is 70° C.; then wash with deionized water and dry at 40° C. for 18 hours. A braided tube-reinforced polyvinylidene fluoride hollow fiber membrane with high bonding strength was obtained.

Example 2-4

1) Immerse a polyester fiber hollow braided tube with an inner diameter of 1.0mm and an outer diameter of 1.7mm in 8wt% sodium hydroxide solution, treat it at 60°C for 15min, then wash it with deionized water, and centrifuge at a speed of 8000 rpm 10min, dry at 80°C.

2) Configure PBS buffer solution, mix it uniformly with tannic acid and polyethyleneimine, and prepare a modified solution whose concentration of tannic acid is 5wt% and polyethyleneimine concentration is 12wt%; The tube was dipped into the modification solution for one coating, treated at 60° C. for 50 minutes, washed with deionized water, and dried by centrifugation.

3) Soak the braided tube after the above treatment in 3.5wt% _CaCl solution for mineralization, and treat it at room temperature (25°C) for 6h to grow nanoparticles (18.6±2.6nm) on the surface of the braided tube; deionized water After washing, dry at 80°C.

4) Under the condition of nitrogen protection, blend polyvinylidene fluoride, PVP, tannic acid and N,N-dimethylacetamide, stir at 80°C for 18 hours, and vacuum defoam to obtain casting solution. The components and their concentrations are as follows:

The number average molecular weight of polyvinylidene fluoride is 2.1×10 ⁵ , and the weight percent concentration is 12%;

The number average molecular weight of PVP is 40,000, and the weight percent concentration is 4%;

The weight percent concentration of tannic acid is 4%;

The weight percent concentration of N,N-dimethylacetamide is 80%.

5) Coat the mineralized braided pipe twice with the casting solution, and enter it into a coagulation bath at 40°C to obtain a polyvinylidene fluoride hollow fiber composite microporous membrane. The air temperature is 30°C and the relative humidity is 75%. The distance of the air section is 10cm.

The coagulation bath is water.

6) Soak the polyvinylidene fluoride hollow fiber composite microporous membrane in hot water for 8 hours for hydrophilization treatment. The temperature of the hot water is 70° C.; then wash with deionized water and dry at 40° C. for 24 hours. A braided tube-reinforced polyvinylidene fluoride hollow fiber membrane with high bonding strength was obtained.

Example 2-5

1) Immerse a polyester fiber hollow braided tube with an inner diameter of 1.0mm and an outer diameter of 1.7mm in 8wt% sodium hydroxide solution, treat it at 60°C for 25min, and then wash it with deionized water at a speed of 5000 rpm Centrifuge for 15 minutes and dry at 80°C.

2) configure PBS buffer solution, mix it with catechol and PEG evenly, and prepare a modified solution with a catechol concentration of 10wt% and a PEG concentration of 15wt%; immerse the braided tube after the above treatment into the The above-mentioned modification solution was applied once, treated at 70°C for 50 minutes, washed with deionized water, and dried by centrifugation.

3) Soak the braided tube after the above treatment in 3.5wt% _CaCl solution for mineralization, and treat it at room temperature (25°C) for 6h to grow nanoparticles (18.6±2.6nm) on the surface of the braided tube; deionized water After washing, dry at 80°C.

4) Under the condition of nitrogen protection, blend polyvinylidene fluoride, PEG, catechol and N,N-dimethylacetamide, stir at 80°C for 20 hours, and vacuum defoam to obtain casting solution, casting solution The components and their concentrations are as follows:

The number average molecular weight of polyvinylidene fluoride is 2.1×10 ⁵ , and the weight percent concentration is 10%;

The number average molecular weight of PEG is 20,000, and the weight percent concentration is 5%;

The weight percent concentration of pyrocatechol is 5%;

The weight percent concentration of N,N-dimethylacetamide is 80%.

5) Coat the mineralized braided pipe twice with the casting solution, and enter it into a coagulation bath at 40°C to obtain a polyvinylidene fluoride hollow fiber composite microporous membrane. The air temperature is 30°C and the relative humidity is 75%. The distance of the air section is 10cm.

The coagulation bath is water.

6) Soak the polyvinylidene fluoride hollow fiber composite microporous membrane in hot water for 10 hours for hydrophilization treatment. The temperature of the hot water is 70° C.; then wash with deionized water and dry at 40° C. for 24 hours. A braided tube-reinforced polyvinylidene fluoride hollow fiber membrane with high bonding strength was obtained.

Example 2-6

1) Immerse a glass fiber hollow braided tube with an inner diameter of 1.0mm and an outer diameter of 1.7mm in a 10wt% sodium hydroxide solution, treat it at a temperature of 70°C for 15min, then wash it with deionized water, and centrifuge at a speed of 5000 rpm 15min, dry at 80°C.

2) PBS buffer solution is configured, and it is uniformly mixed with catechol and chitosan to obtain a modified solution whose catechol concentration is 12wt% and chitosan concentration is 12wt%; The tube was dipped into the modification solution for one coating, treated at 70° C. for 40 minutes, washed with deionized water, and dried by centrifugation.

3) Soak the braided tube after the above treatment in 4.5wt% _CuCl solution for mineralization, and treat it at room temperature (25°C) for 8h to grow nanoparticles (17.2±3.7nm) on the surface of the braided tube; deionized water After washing, dry at 80°C.

4) Under the condition of nitrogen protection, blend polyvinylidene fluoride, PVP, catechol and N,N-dimethylacetamide, stir at 80°C for 18 hours, and vacuum defoam to obtain casting solution, casting solution The components and their concentrations are as follows:

The number average molecular weight of polyvinylidene fluoride is 2.1×10 ⁵ , and the weight percent concentration is 10%;

The number average molecular weight of PVP is 30,000, and the weight percent concentration is 6%;

The weight percent concentration of pyrocatechol is 5.5%;

The weight percent concentration of N,N-dimethylacetamide is 78.5%.

5) Coat the mineralized braided pipe twice with the casting solution, and enter it into a coagulation bath at 40°C to obtain a polyvinylidene fluoride hollow fiber composite microporous membrane. The air temperature is 30°C and the relative humidity is 75%. The distance of the air section is 10cm.

The coagulation bath is water.

6) Soak the polyvinylidene fluoride hollow fiber composite microporous membrane in hot water for 8 hours for hydrophilization treatment. The temperature of the hot water is 70° C.; then wash with deionized water and dry at 40° C. for 24 hours. A braided tube-reinforced polyvinylidene fluoride hollow fiber membrane with high bonding strength was obtained.

Comparative example 2-1

1) Immerse a polyester fiber hollow braided tube with an inner diameter of 1.0mm and an outer diameter of 1.7mm in a 5wt% sodium hydroxide solution, treat it at 50°C for 30min, and then wash it with deionized water at a speed of 3000 rpm Centrifuge for 5 minutes and dry at 80°C.

2) Under the condition of nitrogen protection, blend polyvinylidene fluoride, additives, dopamine and solvent, stir at 80°C for 24 hours, and vacuum defoam to obtain the casting solution. The components and concentrations of the casting solution are as follows:

The number average molecular weight of polyvinylidene fluoride is 2.1×10 ⁵ , and the weight percent concentration is 10%;

The additive is polyvinylpyrrolidone, the number average molecular weight is 30000, and the weight percent concentration is 8.0%;

The weight percent concentration of dopamine is 6%;

The solvent is N,N-dimethylacetamide, and the weight percent concentration is 76%.

3) Coat the braided pipe twice with the casting solution, and put it into a coagulation bath at 40°C to obtain a polyvinylidene fluoride hollow fiber composite microporous membrane. The air temperature is 30°C, the relative humidity is 75%, and the air section distance is 10cm .

The coagulation bath is water.

4) Soak the polyvinylidene fluoride hollow fiber composite microporous membrane in hot water for 6 hours for hydrophilization treatment. The temperature of the hot water is 80° C.; then wash with deionized water and dry at 30° C. for 24 hours. A braided tube-reinforced polyvinylidene fluoride hollow fiber membrane with high bonding strength was obtained.

The hollow fiber membranes prepared in Examples 2-1 to 2-6 and Comparative Example 2-1 were subjected to the following performance tests: the water flux was measured using a dead-end external pressure filter device, that is, the wet membrane after cleaning was now 0.15MPa Pre-compress for 30 minutes, then measure the water flux under external pressure at 0.1MPa; then pass BSA solution to measure the interception rate, and measure the flux recovery rate after washing with water; the interface bonding strength between the braided tube and the separation layer is measured by water recoil pressure Determination; the water contact angle of the dry film was measured by a contact angle meter; the surface and cross-sectional morphology of the dry film were observed by a field emission scanning electron microscope.

The test results are shown in Table 4.

Table 4: Structure and performance parameters of PVDF hollow fiber membranes:

The following examples are provided for the third category of inventions of the present invention:

Example 3-1

1. Treat the fiber bundles composed of 200 0.5 denier polyester filaments and the fiber bundles replacing 4 silver nanowires at 60°C for 30 minutes in a 5wt% sodium hydroxide solution, then wash with deionized water and wash with 3000 Centrifuge at a speed of rpm for 30 min.

2. Stir polyvinylidene fluoride (molecular weight: 210,000), N,N-dimethylacetamide, polyethylene glycol 400, and polyvinylpyrrolidone at a weight ratio of 15:70:10:5 at 80°C for 12 hour, filtered and vacuum degassed for 24 hours to obtain the casting solution.

3. The casting solution is extruded into the mold under the pressure of 0.2MPa, and H ₂ O at 25°C is used as the core fluid to enter the mold through the core fluid tube under the pressure of 0.01MPa; Carry out "herringbone" cross braiding, so that the core liquid tube is fixed in the middle of the braided fiber braided tube, and the fiber braided tube containing silver thread enters the extrusion nozzle at a forward speed of 4m/min under the traction of the friction wheel. Co-extrude the casting solution, core solution and fiber braided tube through an extrusion die, immerse in a 60°C H ₂ O coagulation bath for phase separation, and obtain a silver-containing hollow fiber membrane.

4. Soak the obtained hollow fiber membrane in hot water at 60°C for 12 hours to carry out post-treatment of hydrophilization and membrane pore shaping; dry the hollow fiber membrane after hydrophilization treatment at 30°C for 24 hours, and dry it after drying. A hollow fiber ultrafiltration membrane with high mechanical strength and antibacterial performance was obtained.

Example 3-2

1. Treat the fiber bundles consisting of 150 0.7 denier glass fiber filaments and the fiber bundles replacing 6 silver nanowires at a temperature of 50° C. for 25 minutes in 10 wt % sodium hydroxide solution, and then wash with deionized water to remove Centrifuge at a speed of 5000 rpm for 25 minutes.

2. Stir polyvinylidene fluoride (molecular weight 210,000), N,N-dimethylacetamide, glycerol, and polyvinyl alcohol 30,000 at a weight ratio of 15:70:10:5 at 80°C for 18 hours , filtered, and vacuum defoamed for 18 hours to obtain a casting solution.

3. The casting solution is extruded into the mold under the pressure of 0.2MPa, and H ₂ O at 25°C is used as the core fluid to enter the mold through the core fluid tube under the pressure of 0.01MPa; Carry out "herringbone" cross braiding, so that the core liquid tube is fixed in the middle of the braided fiber braided tube, and the fiber braided tube containing silver thread enters the extrusion nozzle at a forward speed of 3m/min under the traction of the friction wheel. Co-extrude the casting solution, core solution and fiber braided tube through an extrusion die, immerse in a 60°C H ₂ O coagulation bath for phase separation, and obtain a silver-containing hollow fiber membrane.

4. Soak the obtained hollow fiber membrane in hot water at 70°C for 12 hours to carry out post-treatment of hydrophilization and membrane pore shaping; dry the hollow fiber membrane after hydrophilization at 30°C for 24 hours, and dry it A hollow fiber ultrafiltration membrane with high mechanical strength and antibacterial performance was obtained.

Example 3-3

1. Treat the fiber bundle consisting of 200 0.5 denier nylon filaments and the fiber bundle replacing 8 silver nanowires at a temperature of 50° C. for 30 minutes in a 10 wt % sodium hydroxide solution, and then wash with deionized water to Centrifuge at a speed of 5000 rpm for 25 minutes.

2. Stir polyvinylidene fluoride (molecular weight: 210,000), N,N-dimethylacetamide, polyethylene glycol 600, and polyvinyl alcohol 30,000 at a weight ratio of 18:68:9:5 at 80°C After 24 hours, filter and vacuum defoam for 18 hours to obtain the casting solution.

3. The casting solution is extruded into the mold under the pressure of 0.2MPa, and H ₂ O at 25°C is used as the core fluid to enter the mold through the core fluid tube under the pressure of 0.01MPa; Carry out "herringbone" cross braiding, so that the core liquid tube is fixed in the middle of the braided fiber braided tube, and the fiber braided tube containing silver thread enters the extrusion nozzle at a forward speed of 3m/min under the traction of the friction wheel. The casting liquid, core liquid, and fiber braided tube are coextruded through an extrusion die, and immersed in a 60°C N,N-dimethylacetamide/H ₂ O (weight ratio 1:4) coagulation bath for phase separation , to obtain a silver-containing hollow fiber membrane.

4. Soak the obtained hollow fiber membrane in hot water at 60°C for 6 hours to perform post-treatment of hydrophilization and membrane pore shaping; dry the hollow fiber membrane after hydrophilization at 25°C for 24 hours, and dry it A hollow fiber ultrafiltration membrane with high mechanical strength and antibacterial performance was obtained.

Example 3-4

1. Treat a fiber bundle consisting of 300 0.5 denier nylon filaments and a fiber bundle replacing 10 silver nanowires at a temperature of 60° C. for 30 minutes in a 15 wt % sodium hydroxide solution, and then wash with deionized water to Centrifuge at 10,000 rpm for 15 minutes.

2. Stir polyvinylidene fluoride (molecular weight 430,000), N,N-dimethylacetamide, glycerol, and polyethylene glycol 20,000 at a weight ratio of 20:64:10:6 at 90°C for 18 hour, filtered and vacuum degassed for 18 hours to obtain the casting solution.

3. The casting solution is extruded into the mold under the pressure of 0.2MPa, and H ₂ O at 25°C is used as the core fluid to enter the mold through the core fluid tube under the pressure of 0.01MPa; Carry out "herringbone" cross braiding, so that the core liquid tube is fixed in the middle of the braided fiber braided tube, and the fiber braided tube containing silver thread enters the extrusion nozzle at a forward speed of 1.5m/min under the traction of the friction wheel . The casting liquid, core liquid, and fiber braided tube are coextruded through an extrusion die, and immersed in a 60°C N,N-dimethylacetamide/H ₂ O (weight ratio 1:6) coagulation bath to undergo phase separation , to obtain a silver-containing hollow fiber membrane.

4. Soak the obtained hollow fiber membrane in hot water at 60°C for 6 hours to perform post-treatment of hydrophilization and membrane pore shaping; dry the hollow fiber membrane after hydrophilization at 2°C for 24 hours, and dry it A hollow fiber ultrafiltration membrane with high mechanical strength and antibacterial performance was obtained.

Example 3-5

1. Treat the fiber bundle composed of 300 0.5 denier polyester fiber filaments and the fiber bundle replacing 8 silver nanowires in a 15wt% sodium hydroxide solution at a temperature of 60°C for 15min, and then wash it with deionized water, Centrifuge at 10,000 rpm for 15 min.

2. Stir polyvinylidene fluoride (molecular weight: 210,000), N,N-dimethylacetamide, glycerol, and polyethylene glycol 20,000 at a weight ratio of 20:64:10:6 at 90°C for 18 hour, filtered and vacuum degassed for 18 hours to obtain the casting solution.

3. The casting solution is extruded into the mold under the pressure of 0.2MPa, and H ₂ O at 25°C is used as the core fluid to enter the mold through the core fluid tube under the pressure of 0.01MPa; Carry out "herringbone" cross braiding, so that the core liquid tube is fixed in the middle of the braided fiber braided tube, and the fiber braided tube containing silver thread enters the extrusion nozzle at a forward speed of 1.5m/min under the traction of the friction wheel . Co-extrude the casting solution, core solution and fiber braided tube through an extrusion die, and immerse in a water coagulation bath at 60°C for phase separation to obtain a silver-containing hollow fiber membrane.

4. Soak the obtained hollow fiber membrane in hot water at 60°C for 6 hours to perform post-treatment of hydrophilization and membrane pore shaping; dry the hollow fiber membrane after hydrophilization at 25°C for 24 hours, and dry it A hollow fiber ultrafiltration membrane with high mechanical strength and antibacterial performance was obtained.

Example 3-6

1. Treat the fiber bundle consisting of 150 0.5 denier polyester fiber filaments and the fiber bundle replacing 6 silver nanowires in a 15wt% sodium hydroxide solution at a temperature of 60° C. for 15 minutes, and then wash it with deionized water, Centrifuge at 10,000 rpm for 15 min.

2. Stir polyvinylidene fluoride (molecular weight: 210,000), N,N-dimethylacetamide, glycerol, and polyethylene glycol 20,000 at a weight ratio of 15:71:8.5:5.5 at 80°C for 24 hour, filtered and vacuum degassed for 12 hours to obtain the casting solution.

3. The casting solution is extruded into the mold under the pressure of 0.2MPa, and H ₂ O at 25°C is used as the core fluid to enter the mold through the core fluid tube under the pressure of 0.01MPa; Carry out "herringbone" cross braiding, so that the core liquid tube is fixed in the middle of the braided fiber braided tube, and the fiber braided tube containing silver thread enters the extrusion nozzle at a forward speed of 3m/min under the traction of the friction wheel. Co-extrude the casting solution, core solution and fiber braided tube through an extrusion die, and immerse in a water coagulation bath at 60°C for phase separation to obtain a silver-containing hollow fiber membrane.

4. Soak the obtained hollow fiber membrane in hot water at 60°C for 12 hours to perform post-treatment of hydrophilization and membrane pore shaping; dry the hollow fiber membrane after hydrophilization at 25°C for 24 hours, and dry it after drying. A hollow fiber ultrafiltration membrane with high mechanical strength and antibacterial performance was obtained.

Comparative example 3-1

1. Immerse a fiber bundle composed of 200 0.5 denier polyester filaments in a 5wt% sodium hydroxide solution, treat it at 60°C for 30 minutes, then wash it with deionized water, and dry it by centrifugation at a speed of 3000 rpm for 30 minutes.

2. Stir polyvinylidene fluoride (molecular weight: 210,000), N,N-dimethylacetamide, polyethylene glycol 400, and polyvinylpyrrolidone at a weight ratio of 15:70:10:5 at 80°C for 12 hour, filtered and vacuum degassed for 24 hours to obtain the casting solution.

3. The casting solution is extruded into the mold under the pressure of 0.2MPa, and H ₂ O at 25°C is used as the core fluid to enter the mold through the core fluid tube under the pressure of 0.01MPa; Carry out "herringbone" cross braiding, so that the core liquid tube is fixed in the middle of the braided fiber braided tube, and the fiber braided tube containing silver thread enters the extrusion nozzle at a forward speed of 4m/min under the traction of the friction wheel. The casting solution, the core solution, and the fiber braided tube are co-extruded through an extrusion die, immersed in a H ₂ O coagulation bath at 60° C. to undergo phase separation, and a hollow fiber membrane is obtained.

4. Soak the obtained hollow fiber membrane in hot water at 60°C for 12 hours to carry out post-treatment of hydrophilization and membrane pore shaping; dry the hollow fiber membrane after hydrophilization treatment at 30°C for 24 hours, and dry it after drying. A hollow fiber ultrafiltration membrane is obtained.

The hollow fiber ultrafiltration membranes prepared in Examples 3-1 to 3-6 and Comparative Example 3-1 were tested for performance.

The test conditions are as follows: the water flux is measured by the dead-end external pressure filtration device made in the laboratory, that is, the wet membrane after cleaning is now pre-pressed at 0.15MPa for 30min, and then the water flux under the external pressure is measured at 0.1MPa; then BSA is passed through (molecular weight 6700) solution, measure rejection rate, measure flux recovery rate after washing with water; The interfacial bonding strength of braided pipe and separation layer adopts water recoil pressure to measure; The water contact angle of dry film is passed OCA20 (Dataphysics, Germany) The contact angle was measured by a contact angle measuring instrument; the surface and cross-sectional morphology of the dry film were observed by a field emission scanning electron microscope SIRION-100 (FEI, Finland). The model bacteria used in the antibacterial test were Escherichia coli and Staphylococcus aureus.

The water flux, rejection rate, backwash membrane rupture pressure, contact angle, breaking strength, bactericidal rate of Escherichia coli and bactericidal rate of Staphylococcus aureus of the prepared fiber braided reinforced hollow fiber ultrafiltration membrane are shown in Table 5.

table 5

The preferred embodiments of the present invention have been described in detail above, however, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the disclosed content of the present invention. All belong to the protection scope of the present invention.

Claims (12)

1. a kind of preparation method of antimicrobial form hollow-fibre membrane, which is characterized in that this method includes：

(1) in alkaline solution, the filament for being mixed with filamentary silver is subjected to activation process, the filament activated；

(2) filament by the activation is mixed with preparation liquid, and gained mixture is woven, woven hollow fiber is obtained Pipe；

(3) the woven hollow fiber pipe is shaped to antimicrobial form hollow-fibre membrane；

Wherein, the preparation liquid contains film forming polymer, pore-foaming agent and additive A；The additive A is that polyalcohol sum number is divided equally Son amount is less than one or more in 1,000 polyvalent alcohol.

2. it is described to be mixed in the filament of filamentary silver according to the method described in claim 1, wherein, relative to 100 fibers The quantity of silk, the filamentary silver is 2-50 roots；

Preferably, the fiber number of the filamentary silver is 10-500D, preferably 50-300D, more preferably 100-200D；

Preferably, the filament for being mixed with filamentary silver is made of the filamentary silver and film forming filament, and the film forming filament is poly- Ester fiber, Fypro, polyolefine fiber, polyester fiber, polyurethane fiber, polyvinylidene fluoride, polysulfone fibre and glass It is one or more in glass fiber, preferably polyester fiber and/or Fypro；

Preferably, the filametntary fiber number of film forming is 5-10D；

Preferably, the filametntary fiber number of film forming is 10-500D, preferably 50-300D, more preferably 100-200D.

3. method according to claim 1 or 2, wherein in step (1), the alkali compounds in the alkaline solution is One kind or more in alkali metal hydroxide, alkaline earth metal hydroxide, alkali carbonate, alkali metal hydrogencarbonate and ammonia Kind, preferably sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, sodium bicarbonate, carbon It is one or more in potassium hydrogen phthalate and ammonia；

Preferably, the content of the alkali compounds in the alkaline solution is 5-15 weight %.

4. method according to claim 1 or 2, wherein in step (2), in the preparation liquid, the film forming polymer, The weight ratio of pore-foaming agent and additive A is 100：15-70：20-150, preferably 100：20-60：30-100；

Preferably, the film forming polymer is one or more in Kynoar, polyether sulfone and polyacrylonitrile；

Preferably, the pore-foaming agent is polyvinylpyrrolidone, the polyethylene glycol of number-average molecular weight 1,000 or more, polycyclic oxygen It is one or more in ethane, polyvinyl alcohol, polymethyl methacrylate and polyvinyl acetate, more preferably number-average molecular weight For 3,000-50,000 polyvinylpyrrolidones, the polyethylene glycol of number-average molecular weight 1,000-10,000, number-average molecular weight 10, The polyethylene oxide of 000-60,000, the polyvinyl alcohol of number-average molecular weight 8,000-50,000 and molecular weight 11,000-85,000 Polymethyl methacrylate in it is one or more；

Preferably, the additive A is propylene glycol, glycerine, triethylene glycol, number-average molecular weight are 200-800 polyethylene glycol, number One in polypropylene glycol, polyvinylpyrrolidone, polyvinyl butyral and polyvinyl acetate that average molecular weight is 200-800 Kind is a variety of；

Preferably, the solvent in the preparation liquid is N, N '-dimethyl formamide, N, N '-dimethyl acetamide, N- methylpyrroles One or more in alkanone, triethyl phosphate, sulfolane, dimethyl sulfone and benzophenone, the film forming polymer is molten with this The weight ratio of agent is 1：2-8.

5. method according to claim 1 or 4, wherein the preparation liquid also contains polyphenol compound, the Polyphenols Compound is one or more in formula (1) compound represented, tannic acid, formula (2) compound represented and green-tea extract；

Wherein, formula (1)Formula (2)

R¹-R⁶In at least 2 be OH, it is remaining to be each independently H, halogen ,-L-COOM ,-L-SO₃M、-L-NH₂、-L-OH、 The alkylthio group of the alkyl of C1-C6, the alkoxy of C1-C6 or C1-C6；R⁷-R¹⁰And R¹³-R¹⁷In at least 2 be OH, it is remaining R⁷-R¹⁰And R¹³-R¹⁷And R¹¹-R¹²It is each independently H, halogen ,-L-COOM ,-L-SO₃M、-L-NH₂,-L-OH, C1-C6 The alkylthio group of alkyl, the alkoxy of C1-C6 or C1-C6；Each L is each independently selected from the alkylidene of C0-C6；Each M is respectively It independently is H and alkali metal element；

Preferably, R¹-R⁶In at least 2 be OH, it is remaining to be each independently H, halogen ,-L-COOM ,-L-SO₃M、-L- NH₂,-L-OH, the alkyl of C1-C4, the alkoxy of C1-C4 or C1-C4 alkylthio group；R⁷-R¹⁰And R¹³-R¹⁷In at least 2 be OH, remaining R⁷-R¹⁰And R¹³-R¹⁷And R¹¹-R¹²It is each independently H, halogen ,-L-COOM ,-L-SO₃M、-L-NH₂、-L- The alkylthio group of the alkyl of OH, C1-C4, the alkoxy of C1-C4 or C1-C4；Each L is each independently selected from the alkylidene of C0-C4； Each M is each independently H, Na and K；

It is highly preferred that R¹-R⁶In at least 2 be OH, it is remaining to be each independently H, F, Cl, Br ,-COOM ,-CH₂- COOM、-CH₂CH₂-COOM、-CH₂CH₂CH₂-COOM、-CH(CH₃)CH₂-COOM、-CH₂CH(CH₃)-COOM、- CH₂CH₂CH₂CH₂-COOM、-SO₃M、-CH₂-SO₃M、-CH₂CH₂-SO₃M、-CH₂CH₂CH₂-SO₃M、-CH(CH₃)CH₂-SO₃M、- CH₂CH(CH₃)-SO₃M、-CH₂CH₂CH₂CH₂-SO₃M、-NH₂、-CH₂-NH₂、-CH₂CH₂-NH₂、-CH₂CH₂CH₂-NH₂、-CH (CH₃)CH₂-NH₂、-CH₂CH(CH₃)-NH₂、-CH₂CH₂CH₂CH₂-NH₂、-OH、-CH₂-OH、-CH₂CH₂-OH、-CH₂CH₂CH₂- OH、-CH(CH₃)CH₂-OH、-CH₂CH(CH₃)-OH、-CH₂CH₂CH₂CH₂- OH, methyl, ethyl, n-propyl, isopropyl, positive fourth It is base, isobutyl group, sec-butyl, tertiary butyl, methoxyl group, ethyoxyl, positive propoxy, isopropoxy, n-butoxy, isobutoxy, secondary Butoxy, tert-butoxy, methyl mercapto, ethylmercapto group, positive rosickyite base, isopropyisulfanyl, positive butylthio, isobutylthio, secondary butylthio or Tertiary butylthio；

Preferably, in the preparation liquid, the weight ratio of the film forming polymer and polyphenol compound is 100：10-50, preferably It is 100：15-40.

6. according to the method described in claim 5, wherein,

Formula (1) compound represented is selected from following formula compound represented：

Formula (2) compound represented is selected from following formula compound represented：

7. according to the method described in any one of claim 1-6, wherein in step (1), the condition packet of the activation process It includes：Temperature is 30-80 DEG C, time 10-50min.

8. method according to any one of claims 1-7, wherein this method further includes：After step (2), by institute It obtains woven hollow fiber pipe and carries out solidification and washing process, wherein the temperature of the solidification and washing process is 30-80 DEG C.

9. according to the method described in any one of claim 1-8, wherein step (3) further includes in the antimicrobial form by gained Empty fiber membrane carries out hydrophilicity-imparting treatment, and the condition of the hydrophilic treated includes：Using 40-90 DEG C of hot water, 2-24h is impregnated.

10. the antimicrobial form hollow-fibre membrane made from the method described in any one of claim 1-9.

11. including the membrane bioreactor of antimicrobial form hollow-fibre membrane according to any one of claims 10.

12. application of the antimicrobial form hollow-fibre membrane according to any one of claims 10 in UF membrane.