CN105435660B - A kind of antipollution composite multi-layer polymer separation film and preparation method thereof - Google Patents

Abstract

The present invention relates to a kind of antipollution composite multi-layer polymer separation film and preparation method thereof, which has excellent separation function, biocompatibility and contamination resistance.The composite multi-layer polymer separation film is by the multilayered structure with supporting layer and hydrophilic retention functions layer formed thereon, and the interface of hydrophilic retention functions layer and supporting layer is continuous structure.Wherein hydrophilic retention functions layer is the polysulfones based block copolymer composition containing hydrophilic block, and polysulfones family macromolecule is one kind in polysulfones, polyether sulfone, sulfonated polysulfone and polyphenylsulfone.In addition, the hydrophilic retention functions layer surface oxygen element content of composite membrane is more than 17%, there is permanent hydrophilic, do not change with seperation film usage time.The composite multi-layer polymer separation film can be used as supermicro filtration membrane, be also used as nanofiltration, reverse osmosis membrane, forward osmosis membrane basement membrane, be widely used in the separation concentration process in the fields such as biology, medical treatment, electronics and food.

Description

A kind of anti-pollution composite multilayer polymer separation membrane and its preparation method

technical field

The invention relates to an anti-pollution composite multilayer polymer separation membrane, which has excellent separation performance, biocompatibility and anti-pollution ability, and can be used in separation and concentration processes in the fields of biology, medical treatment, electronics and food.

Background technique

In recent years, polysulfone ultrafiltration membranes (including polysulfone, polyethersulfone, sulfonated polysulfone and polyphenylsulfone) have been widely used in various industries due to their excellent performance. For example, the treatment and recovery of industrial wastewater, the purification of urban and rural drinking water, the separation and purification of mixed gases, the separation and concentration process of the food industry, etc. In addition, the excellent biocompatibility of polysulfone membrane has made it have important applications and prospects in biomedicine, such as applied research and application in the fields of dialysis, pathogen isolation, and artificial organs. In addition to being used as an ultrafiltration membrane, polysulfone membrane can be used as a base membrane for nanofiltration, reverse osmosis membrane, and forward osmosis membrane.

However, due to the poor hydrophilicity of the polysulfone material itself, during the membrane separation process, biological suspensions, macromolecules and colloids are easily deposited on the membrane surface and inside the membrane pores, forming irreversible adsorption, resulting in serious membrane pollution, and the polysulfone material is resistant to organic solvents. Poor corrosion performance hinders its application in water medium treatment; in addition, as polysulfone materials are more and more widely used, more and higher requirements are put forward for them. In order to improve the ability of polysulfone materials to resist organic pollution, solve the problem that polysulfone materials are easily corroded by organic solvents, and meet the various needs of polysulfone materials in different industries, chemical workers at home and abroad mainly modify polysulfone materials by blending them. The performance of the membrane can be improved by modifying the properties of the film, the surface treatment of the finished membrane, and the modification of the membrane material body.

Patent US5468393 discloses a method for modifying the surface of the membrane pores with a hydrophilic vinyl monomer grafted polysulfone membrane. The method utilizes the method of ultraviolet radiation to realize the grafting of membrane pores and improve the hydrophilicity of the polysulfone membrane. The modification process of this method is complicated, and has a great influence on the membrane pores and the retention performance of the membrane. Patent 201510566352.8 (Nanjing University of Technology) prepared a modified polysulfone separation membrane by blending polysulfone and a hydrophilic polysulfone block copolymer followed by phase inversion. The hydrophilic segment of the block copolymer can be embedded in the polysulfone separation membrane , improve hydrophilicity. However, in this method of blending modification, the distribution of hydrophilic segments on the surface of the membrane is small, and the improvement of the hydrophilicity of the membrane material is limited.

The present invention aims to develop an anti-pollution composite multilayer polymer separation membrane, which has a multilayer structure with a support layer and a hydrophilic interception function layer formed thereon, and the hydrophilic interception function The interface between the layer and the support layer is a continuous structure. The hydrophilic intercepting functional layer is composed of polysulfone block copolymers containing hydrophilic blocks. In addition, the oxygen element content on the surface of the hydrophilic interception functional layer of the composite membrane is greater than 17%, which has permanent hydrophilicity and does not change with the use time of the separation membrane. The composite multilayer polymer separation membrane has excellent separation function, biocompatibility and anti-pollution ability, and can be widely used in separation and concentration processes in the fields of biology, medical treatment, electronics and food.

The present invention provides following technical scheme:

An anti-pollution composite multilayer polymer separation membrane, characterized in that,

(a) A multilayer structure having a support layer and a hydrophilic intercepting functional layer formed thereon, and the interface between the hydrophilic intercepting functional layer and the supporting layer is a continuous structure.

(b) Both the hydrophilic intercepting functional layer and the supporting layer are porous structures, wherein the diameter of the surface membrane pores of the hydrophilic intercepting functional layer is 1 to 500 nanometers, and the surface membrane at the bonding place of the supporting layer and the hydrophilic intercepting functional layer is The pore diameter is 50~1000 nanometers. The diameter of the membrane pores on the surface of the hydrophilic intercepting functional layer is smaller than the diameter of the membrane pores on the surface of the support layer.

(c) The hydrophilic intercepting functional layer has a strong water wettability, and the water droplet is completely absorbed within 1 second to 10 minutes (preferably 1 second to 1 minute) on the hydrophilic intercepting functional layer. The hydrophilicity of the hydrophilic intercepting functional layer is permanent and does not change with the use time of the separation membrane.

(d) The main component of the hydrophilic intercepting functional layer is a polysulfone block copolymer, which is a block copolymer formed by chemical bonding of the hydrophilic block A and the polysulfone polymer block B, and has a hydrophilic But insoluble in water. Among them, the hydrophilic block A is an oxygen-rich polymer, including polyethylene glycol, polypropylene glycol, polyethylene glycol monomethyl ether, polypropylene glycol monomethyl ether, polyethylene glycol methacrylate (PEGMA) , polyoxypropylene, polyglycerol, branched polyglycerol, polyvinyl alcohol, polypropylene alcohol, dextran, chitosan, hydroxylated polyacrylate, etc. Polysulfone polymer block B is polysulfone, poly One of ethersulfone, polyphenylsulfone and sulfonated polysulfone.

(e) The support layer can be formed by coating on the base material, or without the base material, wherein the base material is a polyester fiber non-woven fabric for reinforcement.

(f) The thickness of the composite multilayer polymer separation membrane is 50 to 300 microns, preferably 80 to 300 microns; wherein the thickness of the hydrophilic interception functional layer is 100 nanometers to 100 microns, accounting for 0.1 to 50% of the separation membrane thickness, preferably 10~20%; the thickness of the support layer is 50~300 microns, accounting for 50~99% of the thickness of the separation membrane, preferably 80~90%.

(g) The composite multilayer polymer separation membrane can be a flat membrane or a hollow fiber separation membrane, and the pure water permeability at 0.1MPa and 25°C is greater than 100 LMH.

Wherein, the surface of the hydrophilic intercepting functional layer is analyzed by X-ray photoelectron spectroscopy (XPS) and its oxygen content is 17-40%, preferably 20-25%; and the oxygen content does not change with the use time of the separation membrane. The oxygen element mainly comes from the hydrophilic block A in the polysulfone block copolymer.

Wherein, the preparation steps of the flat composite multilayer polymer separation membrane include:

(a) the polymer solution is coated on the polyester fiber non-woven fabric,

(b) The polymer solution is impregnated in the polyester fiber nonwoven fabric, and then the polymer solution is contacted with a coagulation bath, thereby forming a liquid impregnated in the polyester fiber nonwoven fabric by phase separation. support layer,

(c) forming a retaining functional layer on said support layer,

(d) Soak the nascent composite multilayer separation membrane formed in (a)(b)(c) in an aqueous solution or alcohol solution or a mixed solution of alcohol and water at 40-95 °C for 5 minutes to 24 hours. The alcohol solution is one or more of methanol, ethanol, propanol, isopropanol, etc., and the alcohol-water mixed solution is a mixture of one or more of methanol, ethanol, propanol, isopropanol, etc. and water Liquid, wherein the volume ratio of water is 1 ~ 99%, preferably 60 ~ 90%.

Here, "impregnated" in (b) refers to a state in which the porous support layer penetrates into the fiber gaps of the substrate.

The manufacturing method of the flat composite multi-layer polymer separation membrane comprises coating the polymer solution α forming the support layer and the polymer solution β forming the intercepting functional layer simultaneously on the base material, and then mixing them with the coagulation bath contact and phase separation occurs. Simultaneous coating includes a state where the polymer solution α is in contact with the polymer solution β before reaching the substrate, that is, when the polymer solution α is coated on the substrate, the polymer solution β is coated on the polymer solution α. At the same time, the coating also includes the state that the polymer solution α is first coated on the substrate, and the polymer solution β is coated on the polymer solution α layer before entering the coagulation bath.

Wherein, the hollow fiber composite multilayer polymer separation membrane is characterized in that the preparation steps include:

(a) The polymer solution α and the polymer solution β are respectively filtered and supplied to the middle layer annular channel and the outer annular channel of the three-channel spinneret: wherein the polymer solution α is supplied to the middle layer annular channel of the three-channel spinneret channel, the polymer solution β is supplied to the outer annular channel of the three-channel spinneret; or, the polymer solution α is supplied to the outer annular channel of the three-channel spinneret, and the polymer solution β is supplied to the three-channel spinneret The middle layer annular channel of the wire head;

(b) The core liquid is supplied into the three-channel spinneret central pipeline;

(c) immerse the nascent hollow fiber composite membrane produced in steps a and b into a gel bath to solidify into a film through an air bath drying process of 5 to 50 centimeters;

(d) Soak the nascent hollow fiber composite multilayer separation membrane formed in steps (a)(b)(c) in an aqueous solution or alcohol solution or a mixed solution of alcohol and water at 40-95°C for 5 minutes to 24 hours. The alcohol solution is one or more of methanol, ethanol, propanol, isopropanol, etc., and the alcohol-water mixed solution is a mixture of one or more of methanol, ethanol, propanol, isopropanol, etc. and water Liquid, wherein the volume ratio of water is 1 ~ 99%, preferably 60 ~ 90%.

(e) The interception functional layer prepared by (a) (b) (c) (d) can be formed on the outer surface of the hollow fiber composite membrane, and can also be formed on the inner surface of the hollow fiber composite membrane. By regulating the polymer solution After β is filtered, it is supplied to the middle layer annular channel or the outer annular channel of the three-channel spinneret to realize.

Wherein, the polymer solution α and the polymer solution β have different compositions. It is characterized by:

(a) The polymer solution α is composed of 8~20 wt.% polysulfone polymer material a or polysulfone block copolymer b, 0~5wt.% co-solvent, 0~15wt.% Pore agent, 0~5wt.% non-solvent, 0~10wt.% surfactant and 45~92wt.% good solvent.

(b) The polymer solution β is composed of 15~25 wt.% polysulfone block copolymer b, 0~5 wt.% co-solvent, 0~15 wt.% porogen, 0~5 wt.% .% non-solvent, 0~10 wt.% surfactant and 40~85 wt.% good solvent.

(c) The solid content concentration a (weight %) of the polymer solution α and the solid content concentration b (weight %) of the polymer solution β satisfy the relational expression of a/b≦1.0.

(d) The polysulfone polymer material a in (a) and (b) is one of polysulfone, polyethersulfone, polyphenylsulfone and sulfonated polysulfone. Wherein the polysulfone block copolymer b is a block copolymer formed by bonding a hydrophilic block A and a polysulfone polymer block B, which is hydrophilic but insoluble in water, wherein the hydrophilic block A The content is 10~40%, preferably 15~30%. The hydrophilic block A is an oxygen-rich polymer, including polyethylene glycol, polypropylene glycol, polyethylene glycol monomethyl ether, polypropylene glycol monomethyl ether, polyethylene glycol methacrylate (PEGMA), Polyoxypropylene, polyvinyl alcohol, polyacryl alcohol, dextran, chitosan, hydroxylated polyacrylate, etc. The polysulfone polymer block B is one of polysulfone, polyethersulfone, polyphenylsulfone and sulfonated polysulfone.

(e) The co-solvents, porogens, non-solvents, surfactants and good solvents of the polymer solutions α and β of (a) and (b) may be the same or different.

Wherein, the porogen is selected from but not limited to macromolecular porogens and small molecular inorganic salt porogens: macromolecular porogens include one or more of polyethylene glycol, polyvinylpyrrolidone, polyvinyl alcohol, etc. . Small molecule inorganic salt porogens include one or more of inorganic salts such as lithium chloride, sodium chloride, calcium chloride, and lithium nitrate, formaldehyde, and formamide.

Non-solvents are selected from but not limited to water, hexane, pentane, benzene, toluene, methanol, ethanol, trichloroethylene, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butylene glycol, pentylene glycol , hexanediol, low molecular weight polyethylene glycol and other aliphatic hydrocarbons, aromatic hydrocarbons, aliphatic alcohols, or their mixed solvents.

The surfactant is selected from but not limited to one or more of Tween 80, Tween 20, sodium dodecylsulfonate, sodium dodecylsulfonate and the like.

The co-solvent is selected from but not limited to one or more of dioxane, tributyl phosphate and the like.

The good solvent is selected from but not limited to N-methyl-2-pyrrolidone (NMP), tetrahydrofuran, dimethylsulfoxide, tetramethylsulfoxide, sulfolane, diphenylsulfone tetramethylurea, dimethylacetamide, One or more mixtures of amides such as dimethylformamide, lower alkyl ketones such as acetone and methyl ethyl ketone, trimethyl phosphate, esters such as γ-butyrolactone, and lactones.

Wherein, in the coagulation bath, the temperature of the coagulation bath is 10-90°C, preferably 20-60°C. The coagulation bath consists of water or a mixed solvent of water and an organic solvent, wherein the organic solvent includes dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethylsulfoxide, tetramethylsulfoxide One of sulfone, sulfolane, diphenyl sulfone or a mixture thereof. The proportion of water in the mixed solvent is not less than 10%.

Wherein, for the core fluid, the temperature of the core fluid is 10-90°C. The coagulation bath consists of water or an organic solvent or a mixed solvent of water and an organic solvent, wherein the organic solvent includes dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, tetra One of methyl sulfoxide, sulfolane, diphenyl sulfone or a mixture thereof.

Wherein, the composite multi-layer polymer separation membrane can be used as an ultra-microfiltration membrane, and can also be used as a base membrane for nanofiltration, reverse osmosis membrane, and forward osmosis membrane.

Wherein, the composite multilayer polymer separation membrane is widely used in the separation and concentration process in the fields of biology, medical treatment, electronics and food, and has good hydrophilicity, biocompatibility and antifouling performance.

In addition, the applicant invented a method for preparing polysulfone block copolymers in patent 201510922936.4 (Yantai Institute of Coastal Zone, Chinese Academy of Sciences), that is, the polysulfone block copolymers involved in the patent to form the interception functional layer, Briefly introduce the following preparation process.

The method relates to a preparation method of a block copolymer, and the tri-block ABA type is used as an example, but not limited to the ABA type block. A method for preparing a three-block block copolymer, all blocks are of the ABA type, wherein block A belongs to the hydrophilic polymer block, and block B belongs to the polysulfone family, and the two can be chemically reacted form block polymers. Wherein the polysulfone block has a molecular weight of at least 1000 and accounts for at least 50% of the total amount of the block copolymer; block B has a molecular weight of at least 100 and accounts for at least 1% of the total amount of the block copolymer, the method comprising the following steps :

(I) in the presence of at least one base, optionally in at least one solvent and further optionally in the presence of an entrainer, by combining at least one aromatic diol or aromatic dialkoxide compound with at least one aromatic diol Halogenated compounds, one of which contains at least one sulfone group, are used to prepare the above-mentioned block copolymer B.

(II) Reacting the above blocks A together, optionally in at least one solvent, optionally capping the block copolymer B.

(III) Washing to recover the block copolymer.

The beneficial effects of the present invention are:

The invention provides an anti-pollution composite multilayer polymer separation membrane and a preparation method thereof. The preparation process of the method is simple, and the preparation of a hydrophilic polysulfone block copolymer is realized by polycondensation. The block copolymer and polysulfone The polymer-like polymer solution is configured to realize the preparation of a hydrophilic separation membrane. Compared with other methods, the preparation process is simple, the cost is low, the effect is obvious, and the production and preparation are easy. The preparation idea is clear and the effect is obvious, which is the first case at home and abroad.

The preparation idea is clear and the effect is obvious, which is the first case at home and abroad.

Detailed ways

The polymer separation membrane of the present invention includes a multilayer structure, which is divided into a hydrophilic layer and a support layer. The hydrophilic layer is prepared by coating the surface of the support layer by a phase inversion method.

In the present invention, the preparation of the hydrophilic separation membrane is realized by disposing the block copolymer and the polysulfone polymer into a polymer solution.

In a preferred embodiment of the present invention, described block copolymer is made by following method:

Preparation of flat film:

Add polysulfone and block copolymer to the solvent, respectively configure polymer solution α and polymer solution β, and use double slot die (Double Slot Die) to simultaneously coat the polymer solution that forms the support layer on the substrate After α and the polymer solution β forming the intercepting functional layer, they are brought into contact with a coagulation bath to cause phase separation. Simultaneous coating includes a state in which the polymer solution α is in contact with the polymer solution β before reaching the substrate, that is, when the polymer solution α is coated on the substrate, the polymer solution β is coated on the polymer solution A. At the same time, the coating also includes the state that the polymer solution α is first coated on the substrate, and the polymer solution β is coated on the polymer solution α layer before entering the coagulation bath.

Preparation of hollow fiber membranes:

(a) The polymer solution α and the polymer solution β are respectively filtered and supplied to the middle layer annular channel and the outer annular channel of the three-channel spinneret: the polymer solution α is supplied to the middle layer annular channel of the three-channel spinneret channel, the polymer solution β is supplied to the outer annular channel of the three-channel spinneret; or, the polymer solution α is supplied to the outer annular channel of the three-channel spinneret, and the polymer solution β is supplied to the three-channel spinneret The middle layer annular channel of the wire head;

(b) Supply the core liquid into the central pipe of the three-channel spinneret;

(c) Immerse the nascent hollow fiber composite membrane produced in steps a and b into a gel bath to solidify into a membrane through an air bath drying process;

(d) Soak the nascent hollow fiber composite multilayer separation membrane formed in steps (a), (b) and (c) in an aqueous solution or alcohol solution or a mixed solution of alcohol and water at a certain temperature for 5 minutes to 24 hours.

Scanning electron microscopy was used to observe the thickness of the hydrophilic layer; XPS was used to analyze the composition of the membrane surface, the contact angle was used to test the wettability of the membrane, the flux and retention of the separation membrane were tested, and the long-term hydrophilicity of the separation membrane was investigated.

The present invention will be further described in detail through specific examples below, but it should not be understood that the scope of the present invention is limited to the following examples. Without departing from the above-mentioned method idea of the present invention, various replacements or changes made according to common technical knowledge and customary means in this field shall be included in the scope of the present invention. The methods are conventional methods unless otherwise specified. The materials can be obtained from open commercial channels unless otherwise specified.

Example 1

20wt.% polysulfone, 5wt.% dioxane, 5wt.% lithium chloride, 0.5wt.% water, 10wt.% Tween 80, 59.5wt.% N-methyl-2-pyrrolidone Configure polymer solution α; 25wt.% polysulfone block polyethylene glycol copolymer, 0.5wt.% tributyl phosphate, 5wt.% propylene glycol, 5wt.% Tween 20, 64.5wt.% di Methylformamide is used to configure polymer solution β, and the two polymer solutions are stirred at room temperature and left to defoam. After coating the polymer solution α forming the support layer and the polymer solution β forming the intercepting functional layer simultaneously on the PET non-woven fabric with a double die head (DoubleSlot Die), immerse in a coagulation bath (the temperature of the coagulation bath is 80°C , the composition of the coagulation bath is an aqueous solution containing 10% dimethylacetamide.) and phase separation occurs. The composite multilayer separation membrane was soaked in pure aqueous solution at 60° C. for 24 hours.

Using a scanning electron microscope, it was found that the hydrophilic interception functional layer accounted for 30% of the thickness of the entire separation membrane; using XPS to analyze the composition of the membrane surface, it was found that the oxygen content on the surface of the membrane was 25%, and the separation membrane was completely infiltrated by water within 1 minute. Its flux test shows that the flux can reach 600LMHbar, and the interception of bovine serum albumin can reach more than 95%. If the separation membrane is immersed in water for a long time (at least 3 months), the hydrophilicity remains unchanged.

Example 2

8wt.% polysulfone, 92wt.% dimethylacetamide to configure polymer solution α; 15wt.% polysulfone block polyethylene glycol, 85wt.% dimethylformamide to configure polymer solution β, Stir the polymer solution at room temperature and let it stand for defoaming. After the polymer solution α forming the support layer and the polymer solution β forming the intercepting functional layer are simultaneously coated on the PET non-woven fabric with a double die head (Double Slot Die), immerse in a coagulation bath (the temperature of the coagulation bath is 10 ℃, the composition of the coagulation bath is an aqueous solution containing 90% dimethylacetamide.) and phase separation occurs. The composite multilayer separation membrane was soaked in an aqueous solution containing 99% methanol at 80° C. for 10 hours.

Observation by scanning electron microscope found that the hydrophilic interception functional layer accounted for 10% of the thickness of the entire separation membrane; using XPS to analyze the surface composition of the membrane, it was found that the oxygen content on the surface of the membrane was 20%, and the separation membrane was completely wetted by water within 1 minute. At 0.1Mbar, the flux test found that the flux can reach 400LMH, and the interception of bovine serum albumin can reach more than 95%. The hydrophilicity remains unchanged when the separation membrane is immersed in water for a long time (at least 6 months).

Example 3

20wt.% polysulfone, 10% PVP (K30), 5 wt.% Tween 80, 65 wt.% dimethyl sulfoxide to configure polymer solution α; 20wt.% polysulfone block polyethylene Diol, 1wt.% tributyl phosphate, 10wt.% Tween 20, 69 wt.% dimethylformamide to configure polymer solution β, stir the polymer solution at room temperature, and let it stand for defoaming. After the polymer solution α forming the support layer and the polymer solution β forming the intercepting functional layer are simultaneously coated on the PET non-woven fabric with a double die head (Double Slot Die), it is immersed in a coagulation bath (the temperature of the coagulation bath is is 20°C, the composition of the coagulation bath is an aqueous solution.) and phase separation occurs. The composite multilayer separation membrane was soaked in an aqueous solution at 95° C. for 4 hours.

Using a scanning electron microscope, it was found that the hydrophilic interception functional layer accounted for 20% of the thickness of the entire separation membrane; using XPS to analyze the composition of the membrane surface, it was found that the oxygen content on the surface of the membrane was 35%, and the separation membrane was completely infiltrated by water within 1 minute. At 0.1Mbar, its flux test found that the pure water passing rate reached 800LMH, and the interception of bovine serum albumin reached more than 95%. The separation membrane was immersed in water for a long time (at least 12 months), and the hydrophilicity remained unchanged.

Example 4-12

15 wt.% polysulfone-b-polyvinyl alcohol block copolymer, 10 wt.% PEG-400, 5wt.% Tween 20, 70wt.% dimethyl sulfoxide to configure polymer solution α; 22wt.% of polysulfone-b-polyvinyl alcohol block copolymer, 1wt.% of tributyl phosphate, 6wt.% of Tween 80, 71wt.% of dimethylformamide to configure polymer solution β, Stir the polymer solution at room temperature and let it stand for defoaming. After simultaneously coating the polymer solution α forming the support layer and the polymer solution β forming the intercepting functional layer on the PET non-woven fabric with a double die head (Double Slot Die), immerse in a coagulation bath (the temperature of the coagulation bath is 20 °C, the composition of the coagulation bath is an aqueous solution containing 5% dimethylformamide.) Phase separation occurs. The composite multilayer separation membrane was soaked in an aqueous solution at 95° C. for 2 hours.

Using a scanning electron microscope to observe the composite separation membrane, the surface membrane pore diameter of the hydrophilic interception functional layer is 5-10 nanometers, and the diameter of the surface membrane pores at the junction of the support layer and the hydrophilic interception functional layer is 50-100 nanometers. The flux was tested, and the results are shown in Table 1.

Table 1

The following examples are for the preparation of hollow fiber separation membranes.

Example 13

20wt.% polysulfone, 5wt.% dioxane, 8wt.% PEG400, 0.5wt.% water, 5wt.% Tween 80, 61.5wt.% N-methyl-2-pyrrolidone configuration high Molecular solution α; 25wt.% polysulfone block polyethylene glycol, 0.5wt.% tributyl phosphate, 1wt.% propylene glycol, 5wt.% Tween 20, 68.5wt.% dimethylformamide Configure the polymer solution β, stir the polymer solution at room temperature, and let it stand for defoaming. The polymer solution α and the polymer solution β are respectively filtered and supplied to the middle layer annular channel and the outer annular channel of the three-channel spinneret: wherein the polymer solution α is supplied to the middle layer annular channel of the three-channel spinneret, and the The polymer solution β is supplied to the outer annular channel of the three-channel spinneret. The aqueous solution (core liquid) containing 50% dimethylacetamide is fed into the central pipe of the three-channel spinneret, the temperature of the core liquid is 80°C, and the nascent hollow fiber composite membrane is immersed in the gel bath through the air bath drying process Solidify into a film; the temperature of the coagulation bath is 60°C, and the composition of the coagulation bath is an aqueous solution containing 10% dimethylacetamide.

Using a scanning electron microscope, it was found that the hydrophilic interception functional layer accounted for 50% of the thickness of the entire separation membrane; using XPS to analyze the composition of the membrane surface, it was found that the oxygen content on the surface of the membrane was 25%, and the separation membrane was completely infiltrated by water within 1 minute. Under the pressure of 0.1MPar, its flux test found that the pure water permeability can reach 400LMH, and the interception of bovine serum albumin can reach more than 95%. If the separation membrane is immersed in water for a long time (at least 1 month), the hydrophilicity remains unchanged. Change.

Example 14

15wt.% polysulfone, 88wt.% N-methyl-2-pyrrolidone to configure polymer solution α; 20wt.% polysulfone block polyethylene glycol, 80wt.% dimethylformamide to configure polymer For solution β, the polymer solution was stirred at room temperature and left to defoam. The polymer solution α and the polymer solution β are respectively filtered and supplied to the middle layer annular channel and the outer annular channel of the three-channel spinneret: the polymer solution α is supplied to the outer annular channel of the three-channel spinneret, and the polymer solution is supplied to the outer annular channel of the three-channel spinneret. The solution β is fed into the middle annular channel of the three-channel spinneret. The aqueous solution (core liquid) containing 99% dimethylformamide is fed into the central pipe of the three-channel spinneret, the temperature of the core liquid is 10°C, and the nascent hollow fiber composite membrane is immersed in the gel bath through the air bath drying process Solidify into a film; the temperature of the coagulation bath is 80°C, and the composition of the coagulation bath is an aqueous solution containing 50% dimethylacetamide.

Using scanning electron microscopy, it was found that the hydrophilic interception functional layer accounted for 0.1% of the thickness of the entire separation membrane; using XPS to analyze the composition of the membrane surface, it was found that the oxygen content on the surface of the membrane was 17%, and the separation membrane was completely wetted by water within 1 minute. Under the pressure of 0.1MPar, its flux test found that the pure water permeability can reach 700LMH, and the interception of bovine serum albumin can reach more than 95%. The separation membrane is immersed in water for a long time (at least 6 months), and the hydrophilicity remains unchanged. Change.

Examples 15-23

20wt.% polysulfone, 5wt.% dioxane, 0.5wt.% ethylene glycol, 10wt.% Tween 80, 64.5wt.% N-methyl-2-pyrrolidone configuration polymer solution α ; 25wt.% polysulfone block polyethylene glycol, 5wt.% tributyl phosphate, 5wt.% polyvinylpyrrolidone, 5wt.% propylene glycol, 60wt.% dimethylformamide configuration polymer solution β , Stir the polymer solution at room temperature and let it stand for defoaming. The polymer solution α and the polymer solution β are respectively filtered and supplied to the middle layer annular channel and the outer annular channel of the three-channel spinneret: wherein the polymer solution α is supplied to the middle layer annular channel of the three-channel spinneret, and the The polymer solution β is supplied to the outer annular channel of the three-channel spinneret. The aqueous solution (core liquid) containing 40% dimethylacetamide is fed into the central pipe of the three-channel spinneret, the temperature of the core liquid is 40°C, and the nascent hollow fiber composite membrane is immersed in the gel bath through the air bath drying process Solidify into a film; the temperature of the coagulation bath is 40°C, and the composition of the coagulation bath is an aqueous solution containing 65% dimethylacetamide.

Using scanning electron microscopy, it was found that the hydrophilic layer accounted for the entire thickness of the separation membrane; XPS was used to analyze the composition of the membrane surface, and the results are shown in Table 2.

Table 2

Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention without limitation, although the present invention has been described in detail with reference to examples, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out Modifications or equivalent replacements without departing from the spirit and scope of the technical solution of the present invention shall be covered by the claims of the present invention.

Claims (10)

1. a kind of antipollution composite multi-layer polymer separation film, which is characterized in that

(a) multilayered structure with supporting layer and hydrophilic retention functions layer formed thereon, and hydrophilic retention functions layer and branch The interface for supportting layer is continuous structure；

(b) hydrophilic retention functions layer and supporting layer described in are all porous structures, wherein the surface fenestra of hydrophilic retention functions layer A diameter of 1 ~ 500 nanometer, the surface film hole diameter of supporting layer and hydrophilic retention functions layer bonding part is 50 ~ 1000 nanometers, hydrophilic Retention functions layer surface film hole diameter is less than support layer surface film hole diameter；

(c) the water infiltration ability of the hydrophilic retention functions layer described in is strong, by water droplet in hydrophilic retention functions layer, -10 minutes 1 second it Interior, water droplet is completely absorbed, and the hydrophily of the hydrophilic retention functions layer has permanently, not with seperation film usage time Variation；

(d) the hydrophilic retention functions layer main component described in is polysulfones based block copolymer, by hydrophilic block A and polysulfones high score Sub- B block has hydrophilic but not soluble in water property, wherein hydrophilic block A by being chemically bonded the block copolymer formed It is rich oxygen containing high polymer, including polyethylene glycol, polypropylene glycol, poly glycol monomethyl ether, polypropylene glycol monomethyl ether, polyethylene glycol Methacrylate, polyoxypropylene, polyvinyl alcohol, POLYPROPYLENE GLYCOL, glucan, chitosan, hydroxylated polyacrylate, polysulfones Family macromolecule B block is one kind in polysulfones, polyether sulfone, polyphenylsulfone and sulfonated polysulfone, (e) described in supporting layer can be on base material It coats, wherein the base material has been the polyester fiber non-woven fabric of humidification；

(f) composite multi-layer polymer separation film thickness is 50 ~ 300 microns；Wherein hydrophilic retention functions layer thickness be 100 nanometers ~ 100 microns；It is 50 ~ 300 microns to support layer thickness；

(g) composite multi-layer polymer separation film can be plate membrane or hollow fiber separating film, the pure water at 0.1 MPa and 25 DEG C Penetration ration is more than 10 LMH.

2. composite multi-layer polymer separation film according to claim 1, which is characterized in that the hydrophilic retention functions layer, Its surface X-ray photoelectron spectroscopic analysis（XPS）It is 17 ~ 40% to analyze its oxygen element content；And oxygen element content is not with separation Film usage time and change, oxygen element is mainly derived from the hydrophilic block A in the polysulfones based block copolymer.

3. a kind of preparation method of composite multi-layer polymer separation film as claimed in claim 1 or 2, which is characterized in that described The preparation process of plate compounding multiple layer polymer seperation film includes：

(a) Polymer Solution is coated on polyester fiber non-woven fabric,

(b) make the Polymer Solution containing being immersed in the polyester fiber non-woven fabric, then make the Polymer Solution and solidification Bath contact is formed from there through phase separation containing the supporting layer being immersed in the polyester fiber non-woven fabric,

(c) hydrophilic retention functions layer is formed on the supporting layer,

(d) (a) (b) (c) is formed by aqueous solution or alcoholic solution or alcohol water of the nascent state composite multi-layer seperation film at 40 ~ 95 DEG C It is impregnated in mixed solution 5 minutes ~ 24 hours, wherein alcoholic solution is one or more, the alcohol in methanol, ethyl alcohol, propyl alcohol, isopropanol Water mixed solution is the mixed liquor of the one or more and water in methanol, ethyl alcohol, propyl alcohol, isopropanol, the wherein volume ratio of water It is 1 ~ 99%,

" impregnation " refers to the state that porosity support layer penetrates into substrate fiber gap wherein in (b).

4. the preparation method of composite multi-layer polymer separation film according to claim 3, which is characterized in that the step packet It includes on base material while coating forms the Polymer Solution α of the supporting layer and forms the Polymer Solution of hydrophilic retention functions layer After β, it is made to be contacted with coagulating bath to be separated, at the same coating include Polymer Solution α before reaching base material and The state of Polymer Solution β contacts, that is, when Polymer Solution α to be coated on base material, Polymer Solution β is coated on height State on molecular solution α；Coating is also first coated on base material including Polymer Solution α simultaneously, will be high before not entering coagulating bath Molecular solution β is coated on the state on Polymer Solution α layers.

5. the preparation method of multiple layer polymer seperation film according to claim 4, which is characterized in that the doughnut is multiple Closing multiple layer polymer seperation film preparation process includes：

(a) after Polymer Solution α and Polymer Solution β being filtered respectively feed triple channel spinning head middle layer circular passage and Outer annular channel：Polymer Solution α is wherein fed to the middle layer circular passage of triple channel spinning head, then by Polymer Solution β Feed the outer annular channel of triple channel spinning head；Or, Polymer Solution α is fed to the outer annular channel of triple channel spinning head, it will Polymer Solution β then feeds the middle layer circular passage of triple channel spinning head；

(b) core liquid is fed into triple channel spinning head central tube；

(c) will（a）With（b）The nascent state hollow fiber composite membrane that step generates is done journey and immersed by 1 ~ 50 centimetre of air bath to coagulate Gu film-forming in bath；

(d) will（a）（b）With（c）Step is formed by aqueous solution of the nascent state doughnut composite multi-layer seperation film at 40 ~ 95 DEG C Or impregnated in alcoholic solution or alcohol water mixed solution 5 minutes ~ 24 hours, wherein alcoholic solution is in methanol, ethyl alcohol, propyl alcohol, isopropanol It is one or more, alcohol water mixed solution is the mixed liquor of methanol, ethyl alcohol, propyl alcohol, one or more and water in isopropanol, The volume ratio of middle water is 1 ~ 99%；

(e) it passes through（a）（b）（c）（d）Prepared hydrophilic retention functions layer can be formed in the outer surface of hollow fiber composite membrane, It can be formed in the inner surface of hollow fiber composite membrane, triple channel spinning head is fed after filtering by regulating and controlling Polymer Solution β Middle layer circular passage or outer annular channel are realized.

6. the preparation method of composite multi-layer polymer separation film according to claim 4 or 5, it is characterised in that：Macromolecule Solution α is different compositions from the Polymer Solution β：

(a) the Polymer Solution α described in, by 8 ~ 20 wt.% polysulfones high molecular material a or polysulfones based block copolymer b, 0 ~ 5wt.% cosolvents, 0 ~ 15wt.% pore-foaming agents, 0 ~ 5wt.% non-solvents, 0 ~ 10wt.% surfactants and 45 ~ 92wt.% are good Solvent forms；

(b) the Polymer Solution β described in, by 15 ~ 25 wt.% polysulfones based block copolymers b, 0 ~ 5wt.% cosolvents, 0 ~ 15wt.% pore-foaming agents, 0 ~ 5wt.% non-solvents, 0 ~ 10wt.% surfactants and 40 ~ 85wt.% good solvents composition；

(c) the solid component concentration b (weights of the solid component concentration a (weight %) and Polymer Solution β of Polymer Solution α Amount %) meet the relational expressions of a/b≤1.0；

(d) (a) and polysulfones high molecular material a in (b) are one in polysulfones, polyether sulfone, polyphenylsulfone and sulfonated polysulfone Kind, wherein polysulfones based block copolymer b is the block copolymer that hydrophilic block A and polysulfones polymer blocks B are bonded together to form, With hydrophily but not soluble in water, the wherein content of hydrophilic block A is 10 ~ 40%, and hydrophilic block A is rich oxygen containing high polymer, Including polyethylene glycol, polypropylene glycol, poly glycol monomethyl ether, polypropylene glycol monomethyl ether, polyethylene glycol methacrylate-styrene polymer, polyoxy Propylene, polyvinyl alcohol, POLYPROPYLENE GLYCOL, glucan, chitosan, hydroxylated polyacrylate, polysulfones polymer blocks B is poly- One kind in sulfone, polyether sulfone, polyphenylsulfone and sulfonated polysulfone,

(e) cosolvent of the Polymer Solution β of the Polymer Solution α sums of (a) and (b), pore-foaming agent, non-solvent, surface are lived Property agent and good solvent can be identical, can also be different；

Wherein, pore-foaming agent is selected from but is not limited only to macromolecule pore-foaming agent and small molecule inorganic salts pore-foaming agent：Macromolecule pore-foaming agent packet Include polyethylene glycol, polyvinylpyrrolidone, polyvinyl alcohol it is one or more, small molecule inorganic salts pore-foaming agent includes chlorination Lithium, sodium chloride, calcium chloride, lithium nitrate, formaldehyde, formamide it is one or more；

Non-solvent is selected from but is not limited only to water, hexane, pentane, benzene, toluene, methanol, ethyl alcohol, trichloro ethylene, ethylene glycol, diethyl two The polyethylene glycol of alcohol, triethylene glycol, propylene glycol, butanediol, pentanediol, hexylene glycol, low molecular weight；

Surfactant is selected from but is not limited only to Tween 80, polysorbas20, dodecyl sodium sulfate it is one or more；

It is one or more that cosolvent is selected from but is not limited only to dioxane, tributyl phosphate；

It is sub- that good solvent is selected from but is not limited only to n-methyl-2-pyrrolidone (NMP), tetrahydrofuran, dimethyl sulfoxide (DMSO), tetramethyl Amides, acetone, the methyl ethyl ketone such as sulfone, sulfolane, diphenyl sulfone tetramethylurea, dimethylacetylamide, dimethylformamide.

7. the preparation method of the composite multi-layer polymer separation film according to claim 3 or 4 or 5, which is characterized in that solidification The temperature of bath is 10 ~ 90 DEG C, and the group of coagulating bath becomes the mixed solvent of water or water and organic solvent, and wherein organic solvent includes two Methylformamide, dimethylacetylamide, n-methyl-2-pyrrolidone, dimethyl sulfoxide (DMSO), tetramethyl sulfoxide, sulfolane, diphenyl The ratio of or mixtures thereof one kind in sulfone, in the mixed solvent water is not less than 10%.

8. the preparation method of composite multi-layer polymer separation film according to claim 5, which is characterized in that the temperature of core liquid It it is 10 ~ 90 DEG C, the group of coagulating bath becomes the mixed solvent of water or organic solvent or water and organic solvent, and wherein organic solvent includes Dimethylformamide, dimethylacetylamide, n-methyl-2-pyrrolidone, dimethyl sulfoxide (DMSO), tetramethyl sulfoxide, sulfolane, hexichol Or mixtures thereof one kind in base sulfone.

9. composite multi-layer polymer separation film according to claim 1 or 2, can be used as supermicro filtration membrane, it is also used as receiving Filter, reverse osmosis membrane, forward osmosis membrane basement membrane.

10. composite multi-layer polymer separation film according to claim 1 or 2, be widely used in biology, medical treatment, electronics and The separation concentration process of field of food.