WO2021139094A1 - 一种用于制备分离膜的常温选择性溶胀开孔方法 - Google Patents

一种用于制备分离膜的常温选择性溶胀开孔方法 Download PDF

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WO2021139094A1
WO2021139094A1 PCT/CN2020/097143 CN2020097143W WO2021139094A1 WO 2021139094 A1 WO2021139094 A1 WO 2021139094A1 CN 2020097143 W CN2020097143 W CN 2020097143W WO 2021139094 A1 WO2021139094 A1 WO 2021139094A1
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swelling agent
block copolymer
film
swelling
membrane
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PCT/CN2020/097143
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French (fr)
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汪勇
王延接
周洁梅
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南京工业大学
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Priority to EP20912201.9A priority Critical patent/EP3970837A4/en
Priority to US17/596,985 priority patent/US11504672B2/en
Publication of WO2021139094A1 publication Critical patent/WO2021139094A1/zh

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
    • B01D67/0002—Organic membrane manufacture
    • B01D67/0023—Organic membrane manufacture by inducing porosity into non porous precursor membranes
    • B01D67/003—Organic membrane manufacture by inducing porosity into non porous precursor membranes by selective elimination of components, e.g. by leaching
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
    • B01D67/0081—After-treatment of organic or inorganic membranes
    • B01D67/0088—Physical treatment with compounds, e.g. swelling, coating or impregnation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/02—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/28—Polymers of vinyl aromatic compounds
    • B01D71/281—Polystyrene
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/40—Polymers of unsaturated acids or derivatives thereof, e.g. salts, amides, imides, nitriles, anhydrides, esters
    • B01D71/401—Polymers based on the polymerisation of acrylic acid, e.g. polyacrylate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/44—Polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds, not provided for in a single one of groups B01D71/26-B01D71/42
    • B01D71/441—Polyvinylpyrrolidone
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/76—Macromolecular material not specifically provided for in a single one of groups B01D71/08 - B01D71/74
    • B01D71/80—Block polymers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2323/00—Details relating to membrane preparation
    • B01D2323/15—Use of additives
    • B01D2323/16—Swelling agents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2325/00—Details relating to properties of membranes
    • B01D2325/39—Amphiphilic membranes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/28—Polymers of vinyl aromatic compounds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/52—Polyethers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/66—Polymers having sulfur in the main chain, with or without nitrogen, oxygen or carbon only
    • B01D71/68—Polysulfones; Polyethersulfones

Definitions

  • the invention belongs to the technical field of porous materials and separation membranes, and specifically relates to a method for preparing separation membranes by selective swelling and opening at room temperature.
  • Block copolymers are special polymers made up of two or more thermodynamically incompatible homopolymer segments connected by covalent bonds. Due to the thermodynamic incompatibility between the various segments of the block copolymer, under certain conditions, the block copolymer will undergo phase separation on a microscopic scale, that is, microphase separation.
  • the phase region of the dispersed phase formed by the microphase separation is generally in the range of ⁇ 5-50nm. If the phase region is transformed into pores in a certain way, a mesoporous structure with a pore diameter of ⁇ 5-50nm can be obtained. This feature gives block copolymers a wide range of applications in water treatment, especially in the field of ultrafiltration membranes for the separation of macromolecular proteins and nanoparticles.
  • the first thing that needs to be solved is the problem of pore formation, that is, how to convert the formed microdomains of the dispersed phase into a pore structure to form a continuous mass transfer channel.
  • the traditional method is to chemically etch away the unstable dispersed phase to form holes, leaving the host phase as a separation matrix.
  • this method requires harsh pore-forming conditions and is only effective for specific block copolymers, which greatly limits the practicability of this method.
  • selective swelling has attracted attention as a pore-forming method with relatively mild conditions and no chemical reaction in block copolymer membrane production.
  • the present invention proposes a method of using a mixed solvent as a swelling agent for selective swelling and rapid pore opening at room temperature.
  • a room temperature selective swelling and pore opening method for preparing separation membranes includes:
  • the composite swelling agent is composed of 60-96% of the first swelling agent and 4-40% of the second swelling agent in volume fraction; the first swelling agent is an alcohol solvent; Two swelling agents are selected from toluene, o-xylene, styrene, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, tetrahydrofuran, 1,4-dioxane Any one or a mixture of two or more.
  • the second swelling agent is selected from any one or a mixture of two or more of toluene, styrene, methylene chloride, tetrahydrofuran or 1,4-dioxane; most preferably 1 ,4-Dioxane.
  • the temperature is 20°C.
  • the treatment time is 5-30 min or 4h-8h.
  • the treatment with the composite swelling agent can be in various existing ways, either the dense film is immersed in the composite swelling agent, or the composite swelling agent is immersed in the composite swelling agent.
  • the swelling agent is smeared on the surface of the dense film.
  • the composite swelling agent treatment is to immerse the dense film in the composite swelling agent; and in the composite swelling agent, the volume fraction of the second swelling agent is It is 12%-24%, preferably accounting for a volume fraction of 12-16%; most preferably accounting for a volume fraction of 12%.
  • the solvent is ethanol and 1,4-dioxane, wherein the volume fraction of 1,4-dioxane is 12%; the treatment temperature is 20°C; the treatment time For 8h.
  • the solvent is ethanol and 1,4-dioxane, wherein the volume fraction of 1,4-dioxane is 16%; the treatment temperature is 20°C ; Processing time is 4h.
  • the solvents are ethanol and toluene, wherein the volume fraction of toluene is 12%; the treatment temperature is 20°C; and the treatment time is 4 hours.
  • the composite swelling agent treatment is to apply the composite swelling agent on the surface of the dense film; and in the composite swelling agent, the volume occupied by the second swelling agent.
  • the fraction is 16-40%, preferably 20-40% by volume.
  • the solvents are ethanol and dichloromethane, wherein the volume fraction of dichloromethane is 16%; the treatment temperature is 20°C; and the treatment time is 5 min.
  • the solvent is ethanol and tetrahydrofuran, wherein the volume fraction of tetrahydrofuran is 40%; the treatment temperature is 20°C; and the treatment time is 5-10 min.
  • the amphiphilic block copolymer can be a variety of amphiphilic block copolymers that can undergo microphase separation, and the dispersed phase in the amphiphilic block copolymer can be selectively Swelling causes pores.
  • the preferred amphiphilic block copolymer of the present invention consists of block A and block B (AB), wherein the block A is selected from any one of polystyrene (PS) or polysulfone (PSF), so
  • the block B is selected from poly(2-vinylpyridine) (P2VP), polyethylene oxide (PEO), polyethylene glycol (PEG) or polymethacrylate N,N-dimethylaminoethyl (PDMAEMA) ), the total molecular weight of the amphiphilic block copolymer is 5-10 million Daltons; more preferably, the block A is polystyrene (PS), and more preferably the block B is poly(2-vinylpyridine) (P2VP), polyN,N-dimethylaminoethyl methacrylate (PDMAEMA) or polyethylene glycol (PEG).
  • P2VP poly(2-vinylpyridine)
  • PEO polyethylene oxide
  • PEG polyethylene glycol
  • PDMAEMA polyme
  • the block B accounts for 10-40% of the total volume of the amphiphilic block copolymer.
  • the amphiphilic block copolymer and its molecular weight are respectively PS 53 -P2VP 21 , PS 60 -PEO 36 , PSF 60 -PEG 20 or PS 70.1 -PDMAEMA 21.5 , and the unit is Kilodaltons.
  • the use of the amphiphilic block copolymer to prepare a dense film adopts the prior art to prepare the amphiphilic block copolymer with an organic solvent to form a film-making solution and then coat the film to make the film.
  • a solution coating method can be easily implemented in a laboratory, but it can also be prepared by melting the block copolymer and then extruding and other processing methods.
  • the step is to prepare the amphiphilic block copolymer with an organic solvent to form a film-forming solution with a concentration of 0.5-10 wt%, and then coat the film to obtain the dense film.
  • the concentration of the film forming solution is preferably 2 wt%.
  • the organic solvent can be selected from chloroform, dichloromethane, tetrahydrofuran or N,N-dimethylformamide, preferably chloroform.
  • the coating film production can be a variety of film production methods in the prior art, for example, the film production solution can be spin-coated on a silicon wafer substrate in a conventional amount and then dried to form a film; The film liquid is spin-coated on the microporous substrate in a conventional amount and then dried to form a film; or the film-making liquid may be drip-coated on the silicon wafer substrate in a conventional amount and then dried to form a film; most preferably, the film is spin-coated to form a film.
  • the amphiphilic block copolymer is prepared into a membrane-making liquid with chloroform as a solvent, wherein the concentration of the membrane-making liquid is 1-2wt%, and the amphiphilic block copolymer is composed of block A and block B (AB), wherein the block A is selected from any one of polystyrene (PS) or polysulfone (PSF), and the block B is selected from poly(2-vinylpyridine) (P2VP), poly Any one of ethylene oxide (PEO), polyethylene glycol (PEG) or polymethacrylic acid N,N-dimethylaminoethyl (PDMAEMA); wherein the block B accounts for the amphiphilic
  • the percentage of the total volume of the block copolymer is 10-40%; the total molecular weight of the amphiphilic block copolymer is 50,000-100,000 Daltons;
  • step (1) Take a certain amount of the film-forming liquid obtained in step (1) by spin coating or drip coating on the silicon wafer substrate, and then place it in a natural environment for 6 hours to completely volatilize the solvent, and then a dense amphiphilic block copolymer can be obtained.
  • Material film Take a certain amount of the film-forming liquid obtained in step (1) by spin coating or drip coating on the silicon wafer substrate, and then place it in a natural environment for 6 hours to completely volatilize the solvent, and then a dense amphiphilic block copolymer can be obtained.
  • the amphiphilic block copolymer film obtained in step (2) is soaked in a container containing a composite swelling agent at 20°C.
  • the composite swelling agent is composed of 84-88% ethanol in volume fraction. And 12-16% of 1,4-dioxane; the amphiphilic block copolymer film is immersed in the composite swelling agent at 20°C for 4-8h to complete the pore formation; The membrane was taken out, washed three times with alcohol reagents, and left to dry at room temperature to obtain an amphiphilic block copolymer membrane with a bicontinuous porous structure.
  • the amphiphilic block copolymer is prepared into a membrane-making liquid with chloroform as a solvent, wherein the concentration of the membrane-making liquid is 1-2wt%, and the amphiphilic block copolymer is composed of block A and block B (AB), wherein the block A is selected from any one of polystyrene (PS) or polysulfone (PSF), and the block B is selected from poly(2-vinylpyridine) (P2VP), poly Any one of ethylene oxide (PEO), polyethylene glycol (PEG) or polymethacrylic acid N,N-dimethylaminoethyl (PDMAEMA); wherein the block B accounts for the amphiphilic
  • the percentage of the total volume of the block copolymer is 10-40%; the total molecular weight of the amphiphilic block copolymer is 50,000-100,000 Daltons;
  • step (1) Take a certain amount of the film-forming liquid obtained in step (1) by spin coating or drip coating on the silicon wafer substrate, and then place it in a natural environment for 6 hours to completely volatilize the solvent, and then a dense amphiphilic block copolymer can be obtained.
  • Material film Take a certain amount of the film-forming liquid obtained in step (1) by spin coating or drip coating on the silicon wafer substrate, and then place it in a natural environment for 6 hours to completely volatilize the solvent, and then a dense amphiphilic block copolymer can be obtained.
  • step (2) Coat the surface of the amphiphilic block copolymer membrane obtained in step (2) with a composite swelling agent, and place it at 20°C for 5-10 minutes, until the composite swelling agent is completely volatilized and dried to obtain a two-continuous porous structure.
  • a hydrophilic block copolymer film; the composite swelling agent is composed of 60-84% ethanol and 16-40% dichloromethane or tetrahydrofuran in terms of volume fraction.
  • the temperature required for the selective swelling and opening of the block copolymer is a higher temperature of 50°C to 80°C. In this case, a large amount of energy is consumed, and the cost is higher in industrial production and due to Safety and environmental hazards caused by heating solvents. In addition, it is not conducive to the selective swelling and opening of temperature-sensitive block copolymers.
  • the inventors have discovered through research that adding a specific organic reagent (ie, the second swelling agent of the present invention) to alcohols can effectively realize the selective swelling and opening of the block copolymer at room temperature; and the present invention Based on a large number of experiments, it has been found that many swelling reagents that can be used for high-temperature selective swelling and opening in the prior art can not all be used in the present invention to achieve selective swelling at room temperature by mixing with alcohol reagents, although it is generally considered to adjust Extending the swelling time will improve the selective swelling effect.
  • a specific organic reagent ie, the second swelling agent of the present invention
  • the inventors also found that increasing the concentration of the second swelling agent can significantly increase the swelling effect, that is, reduce the swelling time and increase the swelling degree.
  • swelling at room temperature means that no heating is required so that the swelling form is no longer limited to soaking the film in an excess (a dozen milliliters or more) of swelling agent. Swollen form.
  • the amount of selected reagents is small, the swelling agent is highly volatile, and the entire swelling process only lasts a few minutes.
  • the room temperature selective swelling method of the present invention has universality for the selective swelling of block copolymers, and can be widely used in the pore opening process of a variety of block copolymers;
  • the preparation method of the present invention is simple, and the degree of opening can be precisely controlled by changing the reagent type, reagent concentration and time in the swelling agent.
  • the film was swelled with a 12% concentration of 1,4-dioxane composite swelling agent for 1 hour, and the film thickness changed Smaller, the degree of opening is lower; after 8 hours of treatment, the film thickness will further increase; and the 16% concentration of 1,4-dioxane compound swelling agent is selected to swell the film for 4 hours, and the film thickness will further increase;
  • swelling at 20°C for 4 hours can also obtain a higher degree of swelling. Therefore, according to the method of the present invention, an appropriate solvent type, solvent concentration and time can be selected based on the implementation conditions and the target opening degree in actual production.
  • Figure 1 is a graph showing the relationship between the porosity of the PS-P2VP system and the swelling time in different swelling agent systems when the second swelling agent is at a concentration of 12%;
  • Figure 2 is a graph showing the relationship between film thickness and swelling time of PS-P2VP system in 1,4-dioxane/ethanol system at a concentration of 12%;
  • Example 3 is an SEM image of the porous structure of the block copolymer obtained in Example 1;
  • Example 11 is a SEM image of the porous structure of the block copolymer obtained in Example 8.
  • Figure 12 is an SEM image of the porous structure of the block copolymer obtained in Comparative Example 1;
  • Figure 13 is an SEM image of the porous structure of the block copolymer obtained in Comparative Example 1;
  • Figure 17 is an SEM image of the porous structure of the block copolymer obtained in Comparative Example 3.
  • Example 19 is a SEM image of the porous structure of the block copolymer obtained in Example 10.
  • Example 21 is a SEM image of the porous structure of the block copolymer obtained in Example 11;
  • Figure 3 is a SEM image of the surface of the porous block copolymer membrane prepared in this example. It can be seen from the figure that the membrane was treated with a 12% concentration of 1,4-dioxane composite swelling agent for 1 hour at 20°C. Swelling treatment, the surface of the membrane presents a low degree of bicontinuous morphology, and the membrane opening rate is relatively high. It shows that under normal temperature, adding the neutral reagent of the block copolymer dispersed phase and the main phase to the alcohol reagent can achieve selective swelling and opening of pores.
  • the film thickness increased from 238 nm to 333 nm, and the porosity of the film prepared under this condition was calculated to be 28%.
  • Figure 4 is an SEM image of the surface of the porous block copolymer membrane prepared in this example. It can be seen from the figure that the membrane was treated with a 12% concentration of 1,4-dioxane composite swelling agent for 8 hours at 20°C. Swelling treatment, the surface of the membrane presents a high degree of bi-continuous morphology, and the membrane opening rate is relatively high. It shows that extending the swelling time can increase the swelling degree.
  • the film thickness increased from 238 nm to 358 nm, and the porosity of the film prepared under this condition was calculated to be 34%.
  • Figure 5 is a SEM image of the surface of the porous block copolymer membrane prepared in this example. It can be seen from the figure that the membrane was subjected to 4 hours of treatment with a 16% concentration of 1,4-dioxane composite swelling agent at 20°C. Swelling treatment, the surface of the membrane presents a high degree of bi-continuous morphology, and the membrane opening rate is relatively high. It shows that increasing the concentration of 1,4-dioxane in the solvent can promote swelling and increase the degree of swelling.
  • the film thickness increased from 245 nm to 406 m, and the porosity of the film prepared under this condition was calculated to be 40%.
  • Figures 6 and 7 are respectively the surface and cross-sectional SEM images of the porous block copolymer membrane prepared in this example. It can be seen from the figure that the membrane is subjected to 4 hours at 20°C with a 16% concentration dichloromethane composite swelling agent. After swelling treatment, the surface of the membrane presents a low degree of bi-continuous morphology, and the opening rate of the membrane surface is relatively low, but the degree of cross-sectional opening is relatively high. It shows that using a mixed solvent of dichloromethane and ethanol as a swelling agent to selectively swell and open pores at room temperature is effective for the block copolymer system.
  • the film thickness increased from 270 nm to 325 nm, and the porosity of the film prepared under this condition was calculated to be 17%.
  • Figure 8 is a SEM image of the surface of the porous block copolymer membrane prepared in this example. It can be seen from the figure that the membrane surface was swelled for 4 hours at 20°C with a 24% concentration of toluene composite swelling agent. The high degree of bi-continuous morphology indicates that the mixed solvent of toluene and ethanol is used as a swelling agent to selectively swell and open pores at room temperature, which is effective for the block copolymer system.
  • the film thickness increased from 229 nm to 305 nm, and the porosity of the film prepared under this condition was calculated to be 25%.
  • Figure 9 is an SEM image of the surface of the porous block copolymer membrane prepared in this example. It can be seen from the figure that the membrane was subjected to 4 hours of treatment with a 16% concentration of 1,4-dioxane composite swelling agent at 20°C. After swelling treatment, the surface of the film presents a double continuous morphology. It shows that using a mixed solvent of 1,4-dioxane and ethanol as a swelling agent to selectively swell and open pores at room temperature is effective for the block copolymer system.
  • the film thickness increased from 218 nm to 281 nm, and the porosity of the film prepared under this condition was calculated to be 22%.
  • Figure 10 is a SEM image of the surface of the porous block copolymer membrane prepared in this example. It can be seen from the figure that the membrane surface was swelled for 4 hours with a 12% concentration of tetrahydrofuran composite swelling agent at 20°C. With a high degree of bi-continuous morphology, the membrane opening rate is relatively high. It shows that the ethanol/tetrahydrofuran system can be applied to the process of selective swelling and opening at room temperature.
  • Figure 11 is a SEM image of the surface of the porous block copolymer membrane prepared in this example. It can be seen from the figure that the membrane surface is swelled for 4 hours with a 12% concentration of styrene composite swelling agent at 20°C. High degree of bi-continuous morphology, relatively high membrane porosity. It shows that the ethanol/styrene system is suitable for the process of selective swelling and opening at room temperature.
  • the porous block copolymer composite membrane prepared in this embodiment can be used for the separation of macromolecules in the water system.
  • the pure water permeation flux of the composite membrane is ⁇ 530L/(m 2 ⁇ h ⁇ bar), and the rejection rate for bovine serum protein is 68%.
  • Figures 12 and 13 are respectively SEM images of the surface and cross-section of the porous block copolymer membrane prepared in this comparative example. It can be seen from the figure that at 20°C and normal temperature, pure ethanol solvent cannot achieve the overall opening of the polymer membrane, only on the surface There are some shallow pores caused by segregation, and no pore channels are formed in the section. It shows that at room temperature, only the selective reagent of the dispersed phase of the block copolymer cannot achieve selective swelling and opening of pores.
  • Figures 14 and 15 are the SEM images of the surface and cross-section of the porous block copolymer membrane prepared in this comparative example. It can be seen from the figure that at 20°C, the compound swelled with 12% N,N-dimethylformamide. After swelling the film with the agent for 4 hours, the surface of the film has only shallow pores caused by surface segregation, and no pores are formed in the cross section. It shows that only adding the selective reagent of the disperse phase of the block copolymer to the alcohol reagent at room temperature cannot achieve selective swelling and opening of pores.
  • the thickness of the polymer film in this comparative example was increased from 237 nm to 247 nm after swelling, and the porosity of the film prepared under this condition was calculated to be 5%.
  • Figures 16 and 17 are respectively the SEM images of the surface and cross-section of the porous block copolymer membrane prepared in this comparative example. It can be seen from the figure that the membrane was subjected to 4 hours at 20°C with a 12% concentration cyclohexane composite swelling agent. Swelling treatment, the membrane surface has only shallow pores caused by surface segregation, and no pores are formed in the cross section. It shows that under normal temperature, in the alcohol reagent, adding the strong selective reagent of the main phase of the block copolymer can not achieve the selective swelling and opening of the pores.
  • Figures 18 and 19 are respectively the SEM images of the surface and cross-section of the porous block copolymer membrane prepared in this example. It can be seen from the figure that when the content of dichloromethane is high, only a small amount of swelling agent can be used in a short time. Achieve selective swelling and opening. Both the surface and the cross section show a bi-continuous structure. This indicates that increasing the content of the second agent in the swelling agent can significantly reduce the swelling time, and the swelling is performed at room temperature without heating, which also makes it feasible to apply a small amount of swelling agent to the film surface for selective swelling.
  • Figures 20 and 21 are respectively SEM images of the surface and cross-section of the porous block copolymer membrane prepared in this embodiment. It can be seen from the figure that when the content of tetrahydrofuran is high, a small amount of swelling agent can be used to realize the selection of the block copolymer.
  • the surface and cross-section both show a bi-continuous structure.
  • the thickness of the polymer film obtained in this example was increased from 230 nm to 331 nm after swelling, and the porosity of the film prepared under this condition was calculated to be 31%.

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  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
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Abstract

一种用于制备分离膜的常温选择性溶胀开孔方法，包括：将两亲嵌段共聚物致密膜在15-30℃下用复合溶胀剂处理1min-24h，然后去除残余溶剂，室温放置干燥得到双连续多孔结构的两亲嵌段共聚物分离膜；复合溶胀剂由60-96％的第一溶胀剂和4-40％的第二溶胀剂构成，第一溶胀剂为醇类溶剂，第二溶胀剂选自1,4-二氧六环、甲苯、苯乙烯或四氢呋喃等试剂中的任意一种或两种以上的混合物。通过调节溶胀剂中溶剂的组成以及溶胀剂中第二溶胀剂的含量可以调控溶胀程度以及形貌。

Description

一种用于制备分离膜的常温选择性溶胀开孔方法 技术领域
本发明属于多孔材料及分离膜技术领域，具体涉及一种用于制备分离膜的常温选择性溶胀开孔方法。
背景技术
嵌段共聚物是由两种或两种以上热力学不相容的均聚物链段通过共价键连接而成的特殊聚合物。由于嵌段共聚物各链段之间的热力学不相容性，在一定条件下嵌段共聚物会发生微观尺度上的相分离，即微相分离。微相分离所形成的分散相相区一般在～5-50nm范围，如将该相区以一定的方式转变为孔道即可获得孔径在～5-50nm的介孔结构。该特点赋予嵌段共聚物在水处理方面的广泛应用，尤其是在大分子蛋白质及纳米颗粒等物质分离的超滤膜领域。
将微相分离后的嵌段共聚物应用到膜分离领域首先需要解决的是致孔问题，即如何将所形成的分散相微区转化为孔道结构，形成连续的传质通道。传统的方式是将不稳定的分散相以化学方式刻蚀移除形成空穴，从而留下主体相作为分离基质。但该方式所需致孔条件苛刻，且仅对特定的嵌段共聚物有效，极大程度限制了该方式的实用性。近年来，选择性溶胀作为一种条件相对温和且无化学反应的致孔方式在嵌段共聚物制膜方面引起关注。但通常溶胀发生在相对高温(50℃-80℃)环境，能量消耗大，还存在由于加热溶剂造成的环境和安全隐患，而且不利于温度敏感型嵌段共聚物的溶胀成孔。因此，亟待发展在常温条件下的选择性溶胀成孔方法，从而推动实现嵌段共聚物选择性溶胀制备分离膜的规模化应用。
发明内容
本发明针对目前选择性溶胀需高温能耗较高的问题，提出了使用混合溶剂为溶胀剂的常温选择性溶胀快速开孔的方法。
本发明的技术方案为：
一种用于制备分离膜的常温选择性溶胀开孔方法，包括：
将两亲嵌段共聚物致密膜在15-30℃下用复合溶胀剂处理1min-24h，去除残余溶剂后室温放置干燥，得到双连续多孔结构的两亲嵌段共聚物分离膜；
所述的复合溶胀剂，按体积分数计，由60-96％的第一溶胀剂和4-40％的第二溶胀剂构成；所述的第一溶胀剂为醇类溶剂；所述的第二溶胀剂选自甲苯、邻二甲苯、苯乙烯、二氯甲烷、1,2-二氯乙烷、1,1,2-三氯乙烷、四氢呋喃、1,4-二氧六环中的任意一种或两种以上的混合物。
本发明优选的方案中，所述的第二溶胀剂选自甲苯、苯乙烯、二氯甲烷、四氢呋喃或1,4-二氧六环中的任意一种或两种以上的混合物；最优选1,4-二氧六环。
本发明优选的方案中，所述的温度为20℃。
本发明优选的方案中，所述的处理时间为5-30min或4h-8h。
本发明的方案中，所述的用复合溶胀剂处理可以是现有的多种方式，既可以是将所述的致密膜浸没在所述的复合溶胀剂中，也可以是将所述的复合溶胀剂涂抹于所述的致密膜表面。
本发明优选的一种方案中，所述的复合溶胀剂处理是将所述的致密膜浸没在所述的复合溶胀剂中；且所述的复合溶胀剂中，第二溶胀剂所占体积分数为12％-24％，优选占12-16％的体积分数；最优选占12％的体积分数。
本发明更优选的一个实施方式中，所述的溶剂为乙醇与1,4-二氧六环，其中1,4-二氧六环的体积分数为12％；处理温度为20℃；处理时间为8h。
本发明中更优选的另一种实施方式中，所述的溶剂为乙醇与1,4-二氧六环，其中1,4-二氧六环的体积分数为16％；处理温度为20℃；处理时间为4h。
本发明中更优选的再一种实施方式中，所述的溶剂为乙醇与甲苯，其中甲苯的体积分数为12％；处理温度为20℃；处理时间为4h。
本发明优选的另一种方案中，所述的复合溶胀剂处理是将所述的复合溶胀剂涂抹于所述的致密膜表面；且所述的复合溶胀剂中，第二溶胀剂所占体积分数为16-40％，优选占20-40％的体积分数。
本发明更优选的一个实施方式中，所述的溶剂为乙醇与二氯甲烷，其中二氯甲烷的体积分数为16％；处理温度为20℃；处理时间为5min。
本发明中更优选的另一种实施方式中，所述的溶剂为乙醇与四氢呋喃，其中四氢呋喃的体积分数为40％；处理温度为20℃；处理时间为5-10min。
本发明的方案中，所述的两亲嵌段共聚物可以是各种可发生微相分离的两亲嵌段共聚物，且所述两亲嵌段共聚物中的分散相均可通过选择性溶胀致孔。本发明优选的两亲嵌段共聚物 由嵌段A和嵌段B组成(A-B)，其中所述嵌段A选自聚苯乙烯(PS)或聚砜(PSF)中的任意一种，所述嵌段B选自聚(2-乙烯基吡啶)(P2VP)、聚环氧乙烷(PEO)、聚乙二醇(PEG)或聚甲基丙烯酸N,N-二甲氨基乙酯(PDMAEMA)中的任意一种，所述两亲嵌段共聚物的总分子量为5-10万道尔顿；更优选的所述嵌段A是聚苯乙烯(PS)，更优选的所述嵌段B是聚(2-乙烯基吡啶)(P2VP)、聚甲基丙烯酸N,N-二甲氨基乙酯(PDMAEMA)或聚乙二醇(PEG)。
本发明进一步优选的方案中，所述的嵌段B占所述两亲嵌段共聚物总体积的百分比为10-40％。
本发明优选的几个实施方案中，所述的两亲嵌段共聚物及其分子量分别为PS 53-P2VP 21、PS 60-PEO 36、PSF 60-PEG 20或PS 70.1-PDMAEMA 21.5，单位为千道尔顿。
本发明所述的方案中，所述的用两亲嵌段共聚物制备致密膜采用现有技术中将两亲嵌段共聚物用有机溶剂配制成制膜液后涂覆制膜。这样的溶液涂覆的方法在实验室能够非常方便的实施，但也可以采用将嵌段共聚物熔融然后通过挤出等加工方法来制备。
本发明的一种实施方式中，步骤是将两亲嵌段共聚物用有机溶剂配制成0.5-10wt％浓度的制膜液，然后涂覆制膜，得到所述的致密膜。
所述的制膜液浓度优选为2wt％。
所述的有机溶剂可以选自三氯甲烷、二氯甲烷、四氢呋喃或N,N-二甲基甲酰胺，优选三氯甲烷。
所述的涂敷制膜可以是现有技术中的多种制膜方法，例如可以是将所述制膜液以常规量旋涂于硅片基底后烘干成膜；可以是将所述制膜液以常规量旋涂于微孔基底后干燥成膜；也可以是将所述制膜液以常规量滴涂于硅片基底后干燥成膜；最优选旋涂成膜。
本发明优选的一种方案中，其具体步骤是：
(1)制膜液的配制过程
将两亲嵌段共聚物以三氯甲烷为溶剂配制成制膜液，其中，制膜液的浓度为1-2wt％，所述的两亲嵌段共聚物由嵌段A和嵌段B组成(A-B)，其中所述嵌段A选自聚苯乙烯(PS)或聚砜(PSF)中的任意一种，所述嵌段B选自聚(2-乙烯基吡啶)(P2VP)、聚环氧乙烷(PEO)、聚乙二醇(PEG)或聚甲基丙烯酸N,N-二甲氨基乙酯(PDMAEMA)中的任意一种；其中所述的嵌段B占所述两亲嵌段共聚物总体积的百分比为10-40％；所述两亲嵌段共聚物的总分子 量为5-10万道尔顿；
(2)制膜过程
将步骤(1)中得到的制膜液取一定量旋涂或滴涂于硅片基底，接着将其置于自然环境下放置6h从而使溶剂完全挥发，即可得到致密的两亲嵌段共聚物膜；
(3)常温选择性溶胀开孔过程
将步骤(2)中得到的两亲嵌段共聚物膜置于20℃且装有复合溶胀剂的容器中浸泡，其中所述的复合溶胀剂，按体积分数计，由84-88％的乙醇和12-16％的1,4-二氧六环构成；所述的两亲嵌段共聚物膜在所述复合溶胀剂中于20℃下浸泡处理4-8h完成致孔；然后立即将聚合物膜取出，并使用醇类试剂清洗三次，并在室温条件下放置干燥，得到双连续多孔结构的两亲嵌段共聚物膜。
本发明优选的另一种方案中，其具体步骤是：
(1)制膜液的配制过程
将两亲嵌段共聚物以三氯甲烷为溶剂配制成制膜液，其中，制膜液的浓度为1-2wt％，所述的两亲嵌段共聚物由嵌段A和嵌段B组成(A-B)，其中所述嵌段A选自聚苯乙烯(PS)或聚砜(PSF)中的任意一种，所述嵌段B选自聚(2-乙烯基吡啶)(P2VP)、聚环氧乙烷(PEO)、聚乙二醇(PEG)或聚甲基丙烯酸N,N-二甲氨基乙酯(PDMAEMA)中的任意一种；其中所述的嵌段B占所述两亲嵌段共聚物总体积的百分比为10-40％；所述两亲嵌段共聚物的总分子量为5-10万道尔顿；
(2)制膜过程
将步骤(1)中得到的制膜液取一定量旋涂或滴涂于硅片基底，接着将其置于自然环境下放置6h从而使溶剂完全挥发，即可得到致密的两亲嵌段共聚物膜；
(3)常温选择性溶胀开孔过程
在步骤(2)中得到的两亲嵌段共聚物膜表面涂抹复合溶胀剂，并置于20℃下5-10min，直到所述复合溶胀剂完全挥发并达到干燥，得到双连续多孔结构的两亲嵌段共聚物膜；所述的复合溶胀剂，按体积分数计，由60-84％的乙醇和16-40％的二氯甲烷或四氢呋喃构成。
本发明有益技术效果：
(1)本发明在醇类溶剂中仅加入少量的有机试剂，就能够大幅度降低嵌段共聚物选择性 溶胀开孔所需的温度，并显著降低了选择性溶胀时间，降低了选择性溶胀过程中的能量消耗，提高了制膜效率；
现有技术中，嵌段共聚物的选择性溶胀开孔所需的温度时50℃-80℃的较高温度，这种情况下需要消耗大量的能源，在工业生产时成本较高并且存在由于加热溶剂而造成的安全和环境隐患。另外，也不利于温度敏感的嵌段共聚物选择性溶胀开孔。本发明人经研究发现了在醇类中加入特定的有机试剂(即本发明所述的第二溶胀剂)可以在常温下就有效地实现嵌段共聚物的选择性溶胀开孔；而且本发明基于大量试验发现，在现有技术中许多可以用于高温选择性溶胀开孔的溶胀试剂，并非都可以用于本发明中与醇类试剂混配实现常温下的选择性溶胀，虽然通常认为调节延长溶胀时间会对选择性溶胀效果带来提高，但是实验证明，有些可用于高温选择性溶胀的试剂(如三氯甲烷、环己烷、N,N-二甲基甲酰胺等)，在常温下即便延长其溶胀时间也很难发挥有效的作用，(如图1所示)。
此外，本发明人还发现，提高所述第二溶胀剂的浓度，可以显著提高溶胀效果，即减少溶胀时间与提高溶胀程度。与现有技术描述的较高温度下的溶胀相比，在常温下溶胀意味着无需加热从而使得溶胀形式不再受限于将膜浸泡在过量(十几毫升甚至更多)的溶胀剂中的溶胀形式。我们可以使用极少量的(几十微升)高浓度溶胀剂涂抹在膜表面，放置在室温环境下等待其自然挥发干燥，即可实现选择性溶胀开孔。且所选试剂用量较少，溶胀剂挥发性强，整个溶胀过程仅持续数分钟。
(2)本发明的常温选择性溶胀方法对嵌段共聚物的选择性溶胀具有普适性，可广泛用于多种嵌段共聚物的开孔过程；
(3)本发明的制备方法简单，可通过改变溶胀剂中的试剂种类、试剂浓度及时间对开孔程度进行精密控制。
本发明人经过实验发现，采用相同膜材料体系溶胀开孔时，不同的溶剂种类、溶剂浓度和溶胀时间可以获得开孔程度不同的聚合物膜。以PS-P2VP体系的聚合物膜为例，如图2所示，在20℃条件下，使用12％浓度1,4-二氧六环复合溶胀剂对膜进行1h的溶胀处理，膜厚度变化较小，开孔程度较低；处理8h后，膜厚度会在进一步增加；而选择16％浓度1,4-二氧六环复合溶胀剂对膜进行4h的溶胀处理，膜厚度更进一步增加；当选择四氢呋喃与乙醇为溶胀剂时，20℃下溶胀4h同样能够得到较高的溶胀程度。因此，根据本发明的方法，在实际生 产中可以基于实施条件和目标开孔程度来选择合适的溶剂种类、溶剂浓度及时间。
附图说明
图1是在第二溶胀剂为12％浓度的情况下PS-P2VP体系在不同溶胀剂体系中孔隙率随溶胀时间的变化关系图；
图2是在12％浓度下PS-P2VP体系在1,4-二氧六环/乙醇体系中膜厚随溶胀时间的变化关系图；
图3是实施例1中得到的嵌段共聚物多孔结构SEM图；
图4是实施例2中得到的嵌段共聚物多孔结构SEM图；
图5是实施例3中得到的嵌段共聚物多孔结构SEM图；
图6是实施例4中得到的嵌段共聚物多孔结构SEM图；
图7是实施例4中得到的嵌段共聚物多孔结构SEM图；
图8是实施例5中得到的嵌段共聚物多孔结构SEM图；
图9是实施例6中得到的嵌段共聚物多孔结构SEM图；
图10是实施例7中得到的嵌段共聚物多孔结构SEM图；
图11是实施例8中得到的嵌段共聚物多孔结构SEM图；
图12是对比例1中得到的嵌段共聚物多孔结构SEM图；
图13是对比例1中得到的嵌段共聚物多孔结构SEM图；
图14是对比例2中得到的嵌段共聚物多孔结构SEM图；
图15是对比例2中得到的嵌段共聚物多孔结构SEM图；
图16是对比例3中得到的嵌段共聚物多孔结构SEM图；
图17是对比例3中得到的嵌段共聚物多孔结构SEM图；
图18是实施例10中得到的嵌段共聚物多孔结构SEM图；
图19是实施例10中得到的嵌段共聚物多孔结构SEM图；
图20是实施例11中得到的嵌段共聚物多孔结构SEM图；
图21是实施例11中得到的嵌段共聚物多孔结构SEM图；
具体实施方式
下面结合实施例对本发明做更进一步地解释。下列实施例仅用于说明本发明，但并不用 来限定本发明的实施范围。
实施例1
将0.02gPS 53-P2VP 21嵌段共聚物加入到2g氯仿溶液中并充分搅拌溶解，用200μm孔径的滤头过滤所配制的聚合物溶液移除大颗粒杂质；取100μL上述溶液以2000rpm30s旋涂于硅片基底，之后将其置于室温下自然干燥6h从而使溶剂完全挥发，即可得到致密嵌段共聚物膜；将膜浸没在含乙醇与1,4二氧六环的混合溶液中，其中1,4-二氧六环的体积分数为12％，在20℃下浸泡1h后将膜取出，在室温条件下放置干燥。
图3是本实施例中制备得到的多孔嵌段共聚物膜表面SEM图，由图可见：在20℃条件下，使用12％浓度1,4-二氧六环复合溶胀剂对膜进行1h的溶胀处理，膜表面呈现低程度的双连续形貌，膜开孔率相对较高。表明常温下，在醇类试剂中加入嵌段共聚物分散相和主体相的中性试剂可以实现选择性溶胀开孔。
另外，经过测定本实施例中聚合物膜经溶胀后膜厚由238nm提升至333nm，计算得到该条件制备的膜孔隙率为28％。
实施例2
将0.02gPS 53-P2VP 21嵌段共聚物加入到2g氯仿溶液中并充分搅拌溶解，用200μm孔径的滤头过滤所配制的聚合物溶液移除大颗粒杂质；取100μL上述溶液以2000rpm30s旋涂于硅片基底，之后将其置于室温下自然干燥6h从而使溶剂完全挥发，即可得到致密嵌段共聚物膜；将膜浸没在含乙醇与1,4二氧六环的混合溶液中，其中1,4-二氧六环的体积分数为12％，在20℃下浸泡8h后将膜取出，在室温条件下放置干燥。
图4是本实施例中制备得到的多孔嵌段共聚物膜表面SEM图，由图可见：在20℃条件下，使用12％浓度1,4-二氧六环复合溶胀剂对膜进行8h的溶胀处理，膜表面呈现高程度的双连续形貌，膜开孔率相对较高。说明延长溶胀时间可以提高溶胀程度。
另外，经过测定本实施例中聚合物膜经溶胀后膜厚由238nm提升至358nm，计算得到该条件制备的膜孔隙率为34％。
实施例3
将0.02gPS 53-P2VP 21嵌段共聚物加入到2g氯仿溶液中并充分搅拌溶解，用200μm孔径的 滤头过滤所配制的聚合物溶液移除大颗粒杂质；取100μL上述溶液以2000rpm30s旋涂于硅片基底，之后将其置于室温下自然干燥6h从而使溶剂完全挥发，即可得到致密嵌段共聚物膜；将膜浸没在含乙醇与1,4-二氧六环的混合溶液中，其中1,4-二氧六环的体积分数为16％，在20℃下浸泡4h后将膜取出，在室温条件下放置干燥。
图5是本实施例中制备得到的多孔嵌段共聚物膜表面SEM图，由图可见：在20℃条件下，使用16％浓度1,4-二氧六环复合溶胀剂对膜进行4h的溶胀处理，膜表面呈现高程度的双连续形貌，膜开孔率相对较高。说明提高溶剂中1,4-二氧六环的浓度可以促进溶胀进行，提高溶胀程度。
另外，经过测定本实施例中聚合物膜经溶胀后膜厚由245nm提升至406m，计算得到该条件制备的膜孔隙率为40％。
实施例4
将0.02gPS 60-PEO 36嵌段共聚物加入到2g氯仿溶液中并充分搅拌溶解，用200μm孔径的滤头过滤所配制的聚合物溶液移除大颗粒杂质；取100μL上述溶液以2000rpm30s旋涂于硅片基底，之后将其置于室温下自然干燥6h从而使溶剂完全挥发，即可得到致密嵌段共聚物膜；将膜浸没在含乙醇与二氯甲烷的混合溶液中，其中二氯甲烷的体积分数为16％，在20℃下浸泡4h后将膜取出，在室温条件下放置干燥。
图6和图7分别是本实施例中制备得到的多孔嵌段共聚物膜表面和截面SEM图，由图可见：在20℃条件下，使用16％浓度二氯甲烷复合溶胀剂对膜进行4h的溶胀处理，膜表面呈现低程度的双连续形貌，膜表面开孔率相对较低，但截面开孔程度相对较高。说明以二氯甲烷与乙醇的混合溶剂为溶胀剂进行常温选择性溶胀开孔对该嵌段共聚物体系有效。
另外，经过测定本实施例中聚合物膜经溶胀后膜厚由270nm提升至325nm，计算得到该条件制备的膜孔隙率为17％。
实施例5
将0.02gPSF 60-PEG 20嵌段共聚物加入到2g氯仿溶液中并充分搅拌溶解，用200μm孔径的滤头过滤所配制的聚合物溶液移除大颗粒杂质；取100μL上述溶液以2000rpm30s旋涂于硅片基底，之后将其置于室温下自然干燥6h从而使溶剂完全挥发，即可得到致密嵌段共聚物膜；将膜浸没在含乙醇和甲苯的混合溶液中，其中甲苯的体积分数为24％，在20℃下浸泡4h后 将膜取出，在室温条件下放置干燥。
图8是本实施例中制备得到的多孔嵌段共聚物膜表面SEM图，由图可见：在20℃条件下，使用24％浓度甲苯复合溶胀剂对膜进行4h的溶胀处理，膜表面呈现较高程度的双连续形貌，说明以甲苯与乙醇的混合溶剂为溶胀剂进行常温选择性溶胀开孔对该嵌段共聚物体系有效。
另外，经过测定本实施例中聚合物膜经溶胀后膜厚由229nm提升至305nm，计算得到该条件制备的膜孔隙率为25％。
实施例6
将0.02gPS 70.1-PDMAEMA 21.5嵌段共聚物加入到2g氯仿溶液中并充分搅拌溶解，用200μm孔径的滤头过滤所配制的聚合物溶液移除大颗粒杂质；取100μL上述溶液以2000rpm30s旋涂于硅片基底，之后将其置于室温下自然干燥6h从而使溶剂完全挥发，即可得到致密嵌段共聚物膜；将膜浸没在含乙醇和1,4-二氧六环的混合溶液中，其中1,4-二氧六环的体积分数为16％，在20℃下浸泡4h后将膜取出，在室温条件下放置干燥。
图9是本实施例中制备得到的多孔嵌段共聚物膜表面SEM图，由图可见：在20℃条件下，使用16％浓度1,4-二氧六环复合溶胀剂对膜进行4h的溶胀处理，膜表面呈现双连续形貌。说明以1,4-二氧六环与乙醇的混合溶剂为溶胀剂进行常温选择性溶胀开孔对该嵌段共聚物体系有效。
另外，经过测定本实施例中聚合物膜经溶胀后膜厚由218nm提升至281nm，计算得到该条件制备的膜孔隙率为22％。
实施例7
将0.02gPS 53-P2VP 21嵌段共聚物加入到2g氯仿溶液中并充分搅拌溶解，用200μm孔径的滤头过滤所配制的聚合物溶液移除大颗粒杂质；取100μL上述溶液以2000rpm30s旋涂于硅片基底，之后将其置于室温下自然干燥6h从而使溶剂完全挥发，即可得到致密嵌段共聚物膜；将膜浸没在含乙醇与四氢呋喃的混合溶液中，其中四氢呋喃的体积分数为12％，在20℃下浸泡4h后将膜取出，在室温条件下放置干燥。
图10是本实施例中制备得到的多孔嵌段共聚物膜表面SEM图，由图可见：在20℃条件下，使用12％浓度四氢呋喃复合溶胀剂对膜进行4h的溶胀处理，膜表面呈现高程度的双连续 形貌，膜开孔率相对较高。说明乙醇/四氢呋喃体系可适用于常温选择性溶胀开孔过程。
实施例8
将0.02gPS 53-P2VP 21嵌段共聚物加入到2g氯仿溶液中并充分搅拌溶解，用200μm孔径的滤头过滤所配制的聚合物溶液移除大颗粒杂质；取100μL上述溶液以2000rpm30s旋涂于硅片基底，之后将其置于室温下自然干燥6h从而使溶剂完全挥发，即可得到致密嵌段共聚物膜；将膜浸没在含乙醇与苯乙烯的混合溶液中，其中苯乙烯的体积分数为12％，在20℃下浸泡4h后将膜取出，在室温条件下放置干燥。
图11是本实施例中制备得到的多孔嵌段共聚物膜表面SEM图，由图可见：在20℃条件下，使用12％浓度苯乙烯复合溶胀剂对膜进行4h的溶胀处理，膜表面呈现高程度的双连续形貌，膜开孔率相对较高。说明乙醇/苯乙烯体系适用于常温选择性溶胀开孔过程。
实施例9
将0.02gPS 53-P2VP 21嵌段共聚物加入到2g氯仿溶液中并充分搅拌溶解，用200μm孔径的滤头过滤所配制的聚合物溶液移除大颗粒杂质；取100μL上述溶液以2000rpm 30s旋涂于大孔聚偏氟乙烯基底，之后将其置于室温下自然干燥6h从而使溶剂完全挥发，即可得到致密嵌段共聚物膜；将膜浸没在含乙醇与1,4-二氧六环的混合溶液中，其中1,4-二氧六环的体积分数为12％，在20℃下浸泡4h后将膜取出，在室温条件下放置干燥。
本实施例中制备得到的多孔嵌段共聚物复合膜可用于水体系大分子分离。复合膜的纯水渗透通量为～530L/(m 2·h·bar)，并且对牛血清蛋白截留率为68％。
对比例1
将0.02gPS 53-P2VP 21嵌段共聚物加入到2g氯仿溶液中并充分搅拌溶解，用200μm孔径的滤头过滤所配制的聚合物溶液移除大颗粒杂质；取100μL上述溶液以2000rpm30s旋涂于硅片基底，之后将其置于室温下自然干燥6h从而使溶剂完全挥发，即可得到致密嵌段共聚物膜；将膜浸没在纯乙醇试剂中，在20℃下浸泡4h后将膜取出，在室温条件下放置干燥。
图12和13分别是本对比例中制备得到的多孔嵌段共聚物膜表面和截面SEM图，由图可见：在20℃常温下，纯乙醇溶剂无法实现聚合物膜整体开孔，仅在表面存在一些偏析产生的浅孔，截面无孔道生成。表明常温下仅有嵌段共聚物分散相的选择性试剂，无法实现选择性 溶胀开孔。
对比例2
将0.02gPS 53-P2VP 21嵌段共聚物加入到2g氯仿溶液中并充分搅拌溶解，用200μm孔径的滤头过滤所配制的聚合物溶液移除大颗粒杂质；取100μL上述溶液以2000rpm30s旋涂于硅片基底，之后将其置于室温下自然干燥6h从而使溶剂完全挥发，即可得到致密嵌段共聚物膜；将膜浸没在含乙醇与N,N-二甲基甲酰胺的混合溶液中，其中N,N-二甲基甲酰胺的体积分数为12％，在20℃下浸泡4h后将膜取出，在室温条件下放置干燥。
图14和15分别是本对比例中制备得到的多孔嵌段共聚物膜表面和截面SEM图，由图可见：在20℃条件下，使用12％浓度N,N-二甲基甲酰胺复合溶胀剂对膜进行4h的溶胀处理，膜表面仅有表面偏析产生的浅孔，截面无孔道生成。表明常温下在醇类试剂中仅加入嵌段共聚物分散相的选择性试剂，无法实现选择性溶胀开孔。
另外，经过测定本对比例中聚合物膜经溶胀后膜厚由237nm提升至247nm，计算得到该条件制备的膜孔隙率为5％。
对比例3
将0.02gPS 53-P2VP 21嵌段共聚物加入到2g氯仿溶液中并充分搅拌溶解，用200μm孔径的滤头过滤所配制的聚合物溶液移除大颗粒杂质；取100μL上述溶液以2000rpm30s旋涂于硅片基底，之后将其置于室温下自然干燥6h从而使溶剂完全挥发，即可得到致密嵌段共聚物膜；将膜浸没在含乙醇与环己烷的混合溶液中，其中环己烷的体积分数为12％，在20℃下浸泡4h后将膜取出，在室温条件下放置干燥。
图16和17分别是本对比例中制备得到的多孔嵌段共聚物膜表面和截面SEM图，由图可见：在20℃条件下，使用12％浓度环己烷复合溶胀剂对膜进行4h的溶胀处理，膜表面仅有表面偏析产生的浅孔，截面无孔道生成。表明常温下，在醇类试剂中，加入嵌段共聚物主体相的强选择性试剂，同样无法实现选择性溶胀开孔。
实施例10
将0.02gPS 53-P2VP 21嵌段共聚物加入到2g氯仿溶液中并充分搅拌溶解，用200μm孔径的滤头过滤所配制的聚合物溶液移除大颗粒杂质；取200μL上述溶液滴涂于1.5cm×1.5cm大小 的硅片基底，放置于室温下自然干燥12h从而使溶剂完全挥发，即可得到致密嵌段共聚物膜。溶胀剂选用16％体积分数的二氯甲烷与84％体积分数的乙醇的混合溶液，取用50ul的试剂均匀的涂抹在膜表面，在20℃条件下处理至自然挥发干燥，由于二氯甲烷和乙醇挥发性较强，仅5min溶胀剂便完全挥发。
图18和19分别是本实施例中制备得到的多孔嵌段共聚物膜表面和截面SEM图，由图可见：在二氯甲烷含量较高时，仅使用少量的溶胀剂在短时间内即可实现选择性溶胀开孔。表面与截面均呈现出双连续结构。这表明提高溶胀剂中第二试剂的含量可以显著的降低溶胀时间，并且溶胀在常温下进行无需加热，这也使得仅使用少量溶胀剂涂抹在膜表面进行选择性溶胀变得可行。
实施例11
将0.02gPSF 60-PEG 20嵌段共聚物加入到2g氯仿溶液中并充分搅拌溶解，用200μm孔径的滤头过滤所配制的聚合物溶液移除大颗粒杂质；取100μL上述溶液以2000rpm30s旋涂于硅片基底，之后将其置于室温下自然干燥6h从而使溶剂完全挥发，即可得到致密嵌段共聚物膜；溶胀剂选用40％体积分数的四氢呋喃与60％体积分数的乙醇的混合溶液，取用50ul的试剂均匀的涂抹在膜表面，在20℃条件下处理至自然挥发干燥。
图20和21分别是本实施例中制备得到的多孔嵌段共聚物膜表面和截面SEM图，由图可见：在四氢呋喃含量较高时，使用少量的溶胀剂可以实现该嵌段共聚物的选择性溶胀开孔，表面与截面均呈现出双连续结构。
另外，经过测定本实施例得到的聚合物膜经溶胀后膜厚由230nm提升至331nm，计算得到该条件制备的膜孔隙率为31％。

Claims (15)

  1. 一种用于制备分离膜的常温选择性溶胀开孔方法，包括：
    将两亲嵌段共聚物致密膜在15-30℃下用复合溶胀剂处理1min-24h，去除残余溶剂后室温放置干燥，得到双连续多孔结构的两亲嵌段共聚物分离膜；
    所述的复合溶胀剂，按体积分数计，由60-96％的第一溶胀剂和4-40％的第二溶胀剂构成；所述的第一溶胀剂为醇类溶剂；所述的第二溶胀剂选自甲苯、邻二甲苯、苯乙烯、二氯甲烷、1,2-二氯乙烷、1,1,2-三氯乙烷、四氢呋喃、1,4-二氧六环中的任意一种或两种以上的混合物。
  2. 权利要求1所述的方法，其特征在于：所述的第二溶胀剂选自甲苯、苯乙烯、二氯甲烷、四氢呋喃或1,4-二氧六环中的任意一种或两种以上的混合物。
  3. 权利要求1所述的方法，其特征在于：所述的第二溶胀剂为1,4-二氧六环。
  4. 权利要求1所述的方法，其特征在于：所述的醇类溶剂选自甲醇、乙醇、丁醇、异丙醇、乙二醇或丙三醇。
  5. 权利要求1所述的方法，其特征在于：所述的醇类溶剂为乙醇。
  6. 权利要求1所述的方法，其特征在于：所述的温度为20℃。
  7. 权利要求1所述的方法，其特征在于：所述的处理时间为5-10min或4h-8h。
  8. 权利要求1所述的方法，其特征在于：所述的复合溶胀剂处理是将所述的致密膜浸没在所述的复合溶胀剂中；且所述的复合溶胀剂中，第二溶胀剂所占体积分数为12％-24％。
  9. 权利要求8所述的方法，其特征在于：所述的复合溶胀剂中，第二溶胀剂所占体积分数为12-16％。
  10. 权利要求8所述的方法，其特征在于：所述的复合溶胀剂中，第二溶胀剂所占体积分数为12％。
  11. 权利要求1所述的方法，其特征在于：所述的复合溶胀剂处理是将所述的复合溶胀剂涂抹于所述的致密膜表面；且所述的复合溶胀剂中，第二溶胀剂所占体积分数为16-40％。
  12. 权利要求11所述的方法，其特征在于：所述的复合溶胀剂中，第二溶胀剂所占体积 分数为20-40％。
  13. 权利要求1所述的方法，其特征在于：所述的两亲嵌段共聚物由嵌段A和嵌段B组成(A-B)，其中所述嵌段A选自聚苯乙烯(PS)或聚砜(PSF)中的任意一种，所述嵌段B选自聚(2-乙烯基吡啶)(P2VP)、聚环氧乙烷(PEO)、聚乙二醇(PEG)或聚甲基丙烯酸N,N-二甲氨基乙酯(PDMAEMA)中的任意一种，所述两亲嵌段共聚物的总分子量为5-10万道尔顿。
  14. 一种用于制备分离膜的常温选择性溶胀开孔的方法，其特征在于，具体步骤是：
    (1)制膜液的配制过程
    将两亲嵌段共聚物以三氯甲烷为溶剂配制成制膜液，其中，制膜液的浓度为1-2wt％，所述的两亲嵌段共聚物由嵌段A和嵌段B组成(A-B)，其中所述嵌段A选自聚苯乙烯(PS)或聚砜(PSF)中的任意一种，所述嵌段B选自聚(2-乙烯基吡啶)(P2VP)、聚环氧乙烷(PEO)、聚乙二醇(PEG)或聚甲基丙烯酸N,N-二甲氨基乙酯(PDMAEMA)中的任意一种；其中所述的嵌段B占所述两亲嵌段共聚物总体积的百分比为10-40％；所述两亲嵌段共聚物的总分子量为5-10万道尔顿；
    (2)制膜过程
    将步骤(1)中得到的制膜液取一定量旋涂或滴涂于硅片基底，接着将其置于自然环境下放置6h从而使溶剂完全挥发，即可得到致密的两亲嵌段共聚物膜；
    (3)常温选择性溶胀开孔过程
    将步骤(2)中得到的两亲嵌段共聚物膜置于20℃且装有复合溶胀剂的容器中浸泡，其中所述的复合溶胀剂，按体积分数计，由84-88％的乙醇和12-16％的1,4-二氧六环构成；所述的两亲嵌段共聚物膜在所述复合溶胀剂中于20℃下浸泡处理4-8h完成致孔；然后立即将聚合物膜取出，并使用醇类试剂清洗三次，并在室温条件下放置干燥，得到双连续多孔结构的两亲嵌段共聚物膜。
  15. 一种用于分离膜的常温选择性溶胀开孔的方法，其特征在于，具体步骤是：
    (1)制膜液的配制过程
    将两亲嵌段共聚物以三氯甲烷为溶剂配制成制膜液，其中，制膜液的浓度为1-2wt％，所 述的两亲嵌段共聚物由嵌段A和嵌段B组成(A-B)，其中所述嵌段A选自聚苯乙烯(PS)或聚砜(PSF)中的任意一种，所述嵌段B选自聚(2-乙烯基吡啶)(P2VP)、聚环氧乙烷(PEO)、聚乙二醇(PEG)或聚甲基丙烯酸N,N-二甲氨基乙酯(PDMAEMA)中的任意一种；其中所述的嵌段B占所述两亲嵌段共聚物总体积的百分比为10-40％；所述两亲嵌段共聚物的总分子量为5-10万道尔顿；
    (2)制膜过程
    将步骤(1)中得到的制膜液取一定量旋涂或滴涂于硅片基底，接着将其置于自然环境下放置6h从而使溶剂完全挥发，即可得到致密的两亲嵌段共聚物膜；
    (3)常温选择性溶胀开孔过程
    在步骤(2)中得到的两亲嵌段共聚物膜表面涂抹复合溶胀剂，并置于20℃下5-10min，直到所述复合溶胀剂完全挥发并达到干燥，得到双连续多孔结构的两亲嵌段共聚物膜；所述的复合溶胀剂，按体积分数计，由60-84％的乙醇和16-40％的二氯甲烷或四氢呋喃构成。
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CN111167316B (zh) * 2020-01-06 2021-01-01 南京工业大学 一种用于制备分离膜的常温选择性溶胀开孔方法
CN111701467B (zh) * 2020-05-26 2022-05-10 浙江工业大学 一种利用共价键层层自组装提高均孔膜抗污染改性的方法
CN113041848B (zh) * 2021-03-24 2022-09-16 南京工业大学 一种结合选择性溶胀和熔纺拉伸法制备嵌段共聚物中空纤维膜的方法
CN114984767B (zh) * 2022-06-06 2023-10-13 浙江大学 聚合物多孔膜表面智能缩孔方法及其有机溶剂纳滤膜产品
CN117679954B (zh) * 2024-02-01 2024-05-03 自然资源部天津海水淡化与综合利用研究所 一种高通量抗污染的聚醚砜平板微孔膜及其制备方法和应用

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5007944A (en) * 1986-05-09 1991-04-16 Gkss Forschungszentrum Geesthacht Gmbh Process for increasing the selectivity of asymmetric membranes
CN101011645A (zh) * 2006-12-27 2007-08-08 南京工业大学 一种两亲性分子对聚丙烯多孔膜表面的亲水化改性方法
CN101177493A (zh) * 2007-10-26 2008-05-14 厦门大学 一种聚合物有序纳米多孔材料及其制备方法
CN101704957A (zh) * 2009-10-29 2010-05-12 南京工业大学 一种制备具有连续纳米孔道的聚合物薄膜的方法
US8829062B1 (en) * 2006-04-07 2014-09-09 Clarkson University Stimuli-responsive polymer membrane and method of making the same
CN103464015B (zh) * 2013-09-26 2015-12-23 天津工业大学 一种具有纳米有序孔径的温度敏感分离膜的制备方法
CN111167316A (zh) * 2020-01-06 2020-05-19 南京工业大学 一种用于制备分离膜的常温选择性溶胀开孔方法

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59203641A (ja) * 1983-04-30 1984-11-17 Toyo Soda Mfg Co Ltd 両性イオン交換体
US20050220745A1 (en) * 2004-04-01 2005-10-06 L'oreal S.A. Cosmetic compositions containing swelled silicone elastomer powders and gelled block copolymers
CN102764600B (zh) * 2012-08-10 2014-10-29 南京工业大学 基于嵌段共聚物选择性溶胀制备多孔膜的方法
US9162189B1 (en) * 2014-05-30 2015-10-20 Pall Corporation Membrane comprising self-assembled block copolymer and process for producing the same by spin coating (Ia)
CN105418960A (zh) * 2014-09-19 2016-03-23 天津工业大学 一种温度敏感的有序多孔薄膜的构建
US10744748B2 (en) * 2016-02-29 2020-08-18 The Industry & Academic Cooperation In Chungnam National University (Iac) Micro nanoporous membrane, preparing method thereof and microfluidic device using thereof
CN106674580B (zh) * 2017-01-04 2019-04-16 南京工业大学 一种聚砜类纳米多孔聚合物的制备方法
CN110124539B (zh) * 2019-05-22 2022-05-03 南京工业大学 一种用于分离膜的微波强化选择性溶胀开孔方法
US11471839B2 (en) * 2019-08-06 2022-10-18 Uop Llc High selectivity membranes for hydrogen sulfide and carbon dioxide removal from natural gas

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5007944A (en) * 1986-05-09 1991-04-16 Gkss Forschungszentrum Geesthacht Gmbh Process for increasing the selectivity of asymmetric membranes
US8829062B1 (en) * 2006-04-07 2014-09-09 Clarkson University Stimuli-responsive polymer membrane and method of making the same
CN101011645A (zh) * 2006-12-27 2007-08-08 南京工业大学 一种两亲性分子对聚丙烯多孔膜表面的亲水化改性方法
CN101177493A (zh) * 2007-10-26 2008-05-14 厦门大学 一种聚合物有序纳米多孔材料及其制备方法
CN101704957A (zh) * 2009-10-29 2010-05-12 南京工业大学 一种制备具有连续纳米孔道的聚合物薄膜的方法
CN103464015B (zh) * 2013-09-26 2015-12-23 天津工业大学 一种具有纳米有序孔径的温度敏感分离膜的制备方法
CN111167316A (zh) * 2020-01-06 2020-05-19 南京工业大学 一种用于制备分离膜的常温选择性溶胀开孔方法

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