KR20130031527A - Hollow fiber membrane using reinforced supporter made of carbon fiber and it's manufacturing method - Google Patents

Abstract

PURPOSE: A hollow fiber membrane using a reinforced supporter is provided to protect the separation membrane from a high pressure from the inside or the outside of the hollow fiber membrane. CONSTITUTION: A hollow fiber membrane comprises a support element(4) and a separation layer(1) which is formed on the support element. The support element reinforced by carbon fiber is manufactured by weaving carbon fiber(3) and polymer fiber(2). The carbon fiber is manufactured by using a precursor which is selected from polyacrylonitrile based, rayon based, petroleum and/or coal pitch based precursor. The diameter of the carbon fiber is 1-20 micrometer. The inner diameter of the support element is 1-4 mm and the outer diameter is 1.5-5 mm.

Description

Hollow fiber membrane using reinforced supporter made of carbon fiber and it's manufacturing method

Hollow fiber membranes include Micro Filtration, Ultra Filtration, Nano Filtration, Reverse Osmosis, Gas Separation Membrane, Pervaporation Membrane, Vapor Permeation Membrane (vapor permeation membrane) is being used. In general, microfiltration membranes have pores large enough to filter bacteria and emulsions, and ultrafiltration membranes have pores of several nanometers large enough to filter out proteins, polysaccharides, and macromolecules, and nanofiltration membranes have one nanometer. It filters out divalent ions, dyes and low molecular weight organic compounds in and out of the pore size. The reverse osmosis membrane can filter monovalent ions using reverse osmosis. Gas separation membrane, pervaporation membrane, and vapor permeation membrane have a dens membrane structure without pores. As a material for manufacturing the separator, a material such as a polymer, a ceramic, or a metal is used.

The present invention relates to a hollow fiber separation membrane using a carbon fiber reinforced support and a method of manufacturing the same, and more particularly, by manufacturing a hollow fiber separation membrane using a support reinforced using a carbon fiber material of high strength, mechanical strength is increased The present invention relates to a hollow fiber separator and a method of manufacturing the same, which can be used under excellent and high pressure conditions, and have excellent conductivity to impart electric force.

Carbon fiber is light, high strength, low coefficient of thermal expansion, high electrical conductivity, high thermal conductivity, and is a high performance fiber with excellent vibration damping, fatigue, corrosion, wear and chemical stability. Due to these characteristics, it is widely used as carbon fiber reinforced polymer composite material, carbon fiber reinforced metal composite material, carbon fiber reinforced ceramic composite material, and carbon fiber reinforced carbon composite material, and its application area is expanding. The present invention can be said to be a technology in which the carbon fiber properties are applied to the hollow fiber membrane. As a support for a conventional hollow fiber separator, polymer fibers of a single component such as polypropylene and polyester are widely used. However, the support made of this polymer fiber is ductile, so there is a problem that the tube shape is distorted in the process of elongation and elongation. In addition, the strength is weak, there is a problem that can not be used as a membrane support in the separation process operating under high pressure conditions of several tens of atmosphere. Particularly, the hollow fiber membrane reinforced with a conventional support body is distorted in the form of the membrane or the separation layer is not tolerated in the pressure against the pressure applied vertically from the surface of the hollow yarn to the center direction or from the center direction to the surface. There is a problem of losing the function of the separator. In the present invention, the durability and expandability of the hollow fiber membranes can be enhanced so that they can be used in such a high pressure process, and since the membranes reinforced with the conventional polymer fiber support have no electric conductivity, the scope of application thereof is limited. Membrane using a support by using a good electrical conductivity because it can be said that the application range is very high. The present invention is a technology using a carbon fiber that has a very soft property, very tough and hardly stretched, high heat resistance, electrical properties, strong resistance to organic solvents, etc., the conventional hollow fiber membrane using a polymer support It is an advanced technology that overcomes shortcomings and gives new functions.

KR 2003-0062198 A KR 20-0284132 A KR 10-2006-0041402 A KR 10-2005-0063272 A KR 10-2011-0002888 A KR 10-2004-0065934 A US 07267872 B2 US 07909177 B2 US 07413804 B2 JP 11319519 A JP 20178869 A

Polymer Science and Technology, vol. 21, No. 2, April 2010, 130-140p.

Hollow fiber membranes reinforced with existing polymer fiber supports only have low mechanical strength, so they can be easily out of hand when applied to high pressure processes, and they have limitations in separating mixtures with electrical properties because they cannot be given electricity. The purpose of the present invention is to manufacture a hollow fiber separation membrane that can withstand high pressure and has conductivity, and to be widely applicable and developed.

In the present invention, by using a carbon fiber having light properties, high strength, low thermal expansion coefficient, high electrical conductivity, high thermal conductivity, excellent vibration damping ability, fatigue characteristics, corrosion characteristics, wear characteristics and chemical stability as a support, Even if the mixture to be sent to the inside or outside the hollow fiber membrane selectively at high pressure to prevent damage to the membrane layer it can be produced an advanced hollow fiber membrane that overcomes the disadvantages of the existing hollow fiber membrane.

One of the problem solving means of the present invention is to use a support braided by mixing a carbon fiber and a polymer fiber, thereby giving a mechanical strength capable of withstanding high pressure pressure from the inside or outside of the hollow fiber membrane, and can impart an electric force To manufacture a hollow fiber membrane.

Another solution is to use a support braided using only carbon fiber, to provide a mechanical strength capable of withstanding high pressure from the inside or outside of the hollow fiber membrane, and to produce a hollow fiber separator that can impart electric force. It is.

Another solution is that there is no porous microfiltration membrane or ultrafiltration membrane or nanofiltration membrane or reverse osmosis membrane or pores on the outer wall or inner wall of the support prepared above. By forming a dense membrane layer to produce a hollow fiber separation membrane that can be used for water treatment membrane, pervaporation membrane, steam permeation membrane, gas separation membrane, ion separation membrane and the like.

Conventional hollow fiber separator has a disadvantage that it is difficult to apply to high pressure process due to low mechanical strength, it is impossible to separate the mixture using the electrical properties can not impart electricity, but in the present invention the advantages of carbon fiber Since the membrane can be given a function that could not be realized in the existing hollow fiber membrane, the membrane layer can be protected from high pressure applied inside or outside the hollow fiber membrane. As a result, its application and deployment are possible.

1 is a perspective view of a hollow fiber membrane according to the present invention
1A is a perspective view of a hollow fiber separator in which a separator layer is formed on an outer surface of a support
1B is a perspective view of a hollow fiber separator in which a separator layer is formed on an inner surface of a support;
2 is a cross-sectional view of the hollow fiber membrane
Figure 2a is a cross-sectional view of the hollow fiber membrane formed with a membrane layer on the outer surface of the support
Figure 2b is a cross-sectional view of the hollow fiber membrane formed with a separator layer on the inner surface of the support
Figure 3 is a schematic diagram of a support knitting device for knitting with a 24 strand yarn

One of the means for the practice of the present invention is to produce a support 4 by braiding by mixing the carbon fiber (3) and the polymer fiber (2) or by braiding only the carbon fiber. As the carbon fiber used herein, it is preferable to use a carbon fiber (3) prepared by using one of polyacrylonitrile series, rayon series, petroleum and coal pitch series as a precursor, wherein the carbon fiber (3) is a single It is preferable to use a yarn form consisting of several strands of filaments in the range of 1 to 20 micrometers in diameter. The polymer fiber used herein is preferably made of a material such as polypropylene, polyethylene, polyester, nylon, aramid, Teflon, but is not limited to the type of polymer that can be fiberized. At this time, the polymer fiber is preferably used in the form of a yarn (yarn) consisting of a plurality of strands of filaments in the range of 100 ~ 500 daia of single filament thickness. Braiding of the support 4 is carried out in the braiding device 11, by rotating the carbon fiber bobbin (12) or the polymer fiber bobbin (13) wound around a plurality of yarns arranged in a circle, the yarns are twisted with each other to form a tube To form the support 4. The carbon fiber yarn 3 and the polymer fiber yarn 2 are mixed and braided to produce a support 4 (hereinafter referred to as a 'mixture support') or the carbon fiber yarn 3 is braided to produce a support 4. In this case, it is preferable to adjust the number of bobbins 12 and 13 so that the total number of yarns used at this time is about 16 to 48 strands. The number of may be varied, but the range is not limited. In the case of producing the mixed support, the more the number of carbon fiber yarns (3), the better the mechanical strength and electrical properties, but the higher the manufacturing cost, the number of yarns (3) of the carbon fiber is preferably controlled, the total number of yarns In the case of preparing a mixed support having 24 strands (FIG. 3), the number of carbon fiber yarns 3 is preferably about 2 to 4 strands. There is an advantage that can make the most of chemical properties, physical properties and the like. Figure 3 shows one example as a method for producing a support for the present invention, if the support presented in the solution of the present invention or the effect of the invention can be said to belong to the scope of the invention even if the specific manufacturing method is different. have.

One further means for forming the separator layer 1 on the outer wall or the inner wall of the support body 4 prepared above. Separation membrane layer 1 is a porous microfiltration membrane layer or ultrafiltration membrane layer or nanofiltration membrane layer or reverse osmosis membrane layer on the outer wall or the inner wall of the support 4, A pervaporation membrane layer, a vapor permeation membrane layer, and a gas separation membrane may be formed as a separation membrane layer.

The material of the separator layer may be a polymer material, a ceramic material, a metal material, or the like. In the case of ceramics or metal materials other than polymer materials, a solvent and a binder are mixed in an aluminum oxide, silicon nitride, silicon oxide, zeolite-based ceramic powder or nickel and stainless steel-based metal powder to make a uniform solution state. The solution is applied to the inner wall or the outer wall of the single support braided only by the carbon fiber yarn 3, and sintered at a high temperature of 1000 degrees Celsius or higher to form a separator layer to prepare a hollow fiber separator. The ceramic or metal need not be limited to a specific material, and any material that can be made into a uniform solution state by mixing a solvent and a binder may belong to the scope of the present invention.

The material used for the membrane layer is polysulfone, sully sulfone, polyethylene, polyimide, polyacemide, polyacrylonitrile, polyethylene terephthalate, nylon, polypropylene, polybutylene terephthalate, Polyvinyl lytene difluoride, polyamide, acetate cellulose, methyl cellulose-based, but need not be limited to a specific polymer, the method of dissolving the selected polymer in a solvent or melt at high temperature to make a solution state, the phase transition method Alternatively, using a diffusion induction phase separation method or a thermal induction phase separation method, a hollow fiber membrane is formed by coating or coating the outer wall or the inner wall surface of the support with a predetermined thickness to form a membrane layer, or the support on the prepared membrane layer By wrapping and wrapping the hollow fiber separator can be prepared. In this case, the hollow fiber separation membrane may be used for a water treatment membrane or a pervaporation membrane or a vapor permeation membrane or a gas separation membrane, an ion separation membrane, or the like.

Specific details for the implementation of the present invention will be described through the embodiment.

In manufacturing a hollow fiber membrane with a polymer material membrane layer on the outer side of the carbon fiber support, 20 strands of polyester yarn having a thickness of 450 denier are wound around 20 polymer fiber bobbins, and the thickness of the filament is 7 micrometers in diameter. After four strands of phosphorus carbon fiber yarns were respectively wound on four carbon fiber bobbins, a total of 24 strands of yarn were braided to make a tubular support having an outer diameter of 1.8 mm and an inner diameter of 1 mm. To form a separator therein, 10 wt% of polyvinylidene difluoride, 65 wt% of N-methylpyrrolidone, and 25 wt% of polyvinylpyrrolidone were mixed to prepare a solution, and the solution was spun to the outer side of the support. After application, it was immersed in water to induce phase transition, thereby preparing a hollow fiber separator having a separator layer of 0.1 micrometer pore and 200 micrometer thick membrane. The hollow fiber membrane thus prepared was cut to 18 cm in length, the support layer was exposed, and the electrical resistance of both ends of the hollow fiber membrane was measured. The electrical resistance was 0.05 Ω-cm, and the tensile strength was 357 N / mm. ² showed excellent level performance.

In preparing a hollow fiber membrane having a polymer membrane layer on the inner side of the carbon fiber support, to prepare a membrane layer, a solution was prepared by mixing 25 wt% polysulfone, 40 wt% N-methylpyrrolidone, and 35 wt% ethanol. The solution was spun into water and phase-transferd to prepare a separator having a 200 micrometer thick powdery separator layer, and the prepared separator was fixed to a jig located at the center of the circular knitting machine. To form a membrane layer on the inner side of the support, 20 strands of polyester yarn with a filament thickness of 450 deniers were wound around 20 polymer fiber bobbins, and four strands of carbon fiber yarns having a diameter of 7 micrometers of filament were 4 carbons. After winding each of the fiber bobbin, a total of 24 strands of yarn were braided to prepare a hollow fiber membrane having a tube shape having an outer diameter of 1.8 mm and an inner diameter of 1 mm. The hollow fiber membrane thus prepared was cut to 18 cm in length and the electrical resistance of both ends of the hollow fiber membrane was measured. The electrical resistance was 0.05 Ω-cm, which showed excellent electrical conductivity, and the tensile strength was 323 N / mm ² . When the breakage of the membrane layer was measured while flowing high pressure air into the hollow fiber membrane, the membrane layer was not damaged even at 50 bar air pressure.

In order to manufacture a hollow fiber membrane having a metal material membrane layer on the outer surface of the carbon fiber support, 24 strands of carbon fiber yarns each having a diameter of 7 micrometers are wound on 24 carbon fiber bobbins, and then a total of 24 strands of yarn Was braided to form a carbon fiber support formed of only carbon fibers in the form of tubes having an outer diameter of 2 mm and an inner diameter of 1 mm. 70 wt% of stainless steel powder, 15 wt% of polysulfone, and 15 wt% of N-methylpyrrolidone were mixed to prepare a uniform solution, and the solution was spun onto the outer surface of the support. It was then immersed in water at room temperature to induce phase transition to prepare a hollow fiber precursor. The hollow fiber precursor was placed in an electric furnace and kept flowing for 1 hour at 450 degrees Celsius for 1 hour, followed by secondary sintering at 1100 degrees Celsius for 1 hour while flowing hydrogen again. A 0.5 micrometer hollow fiber separator was prepared. The hollow fiber membrane thus prepared was cut to 18 cm in length, the carbon fiber support was exposed, and the electrical resistance of both ends of the hollow fiber membrane was measured. As a result, the electrical resistance was 0.01 전기 -cm. 1420N / mm ² showed very good performance.

In order to manufacture a hollow fiber separator having a ceramic material separator layer on the outer side of the carbon fiber support, 24 strands of carbon fiber yarns having a diameter of 7 micrometers were wound on 24 carbon fiber bobbins, and then a total of 24 strands of yarn Was braided to form a carbon fiber support formed of only carbon fibers in the form of tubes having an outer diameter of 2 mm and an inner diameter of 1 mm. After mixing 70 wt% of alumina powder, polysulfone 15W%, N-methylpyrrolidone with an average diameter of 0.7 micrometer and 15 wt% of N-methylpyrrolidone, the solution was spun onto the outer surface of the support and then coated. The hollow fiber precursor was prepared by inducing phase transition by immersing in water at room temperature. The hollow fiber bulb was placed in an electric furnace to keep air flowing for 1 hour at 450 degrees Celsius, followed by primary sintering, followed by secondary sintering at 1250 degrees Celsius for 2 hours, with an average pore of 0.5 micrometers. A four separation membrane was prepared. The hollow fiber membrane thus prepared was cut to 18 cm, the carbon fiber support was exposed, and the electrical resistance of both ends of the hollow fiber membrane was measured. The electrical resistance was 0.02 Ω-cm and the electrical conductivity was very good. The tensile strength was 1440 N. / mm ² showed very good performance.

[Comparative Example 1]

In order to manufacture a polymeric hollow fiber membrane reinforced with a polymeric fiber support, 24 strands of polyester yarn with a filament thickness of 450 denier were wound around 24 polymer fiber bobbins, and a total of 24 strands of yarn were braided to obtain an outer diameter of 1.8 mm, A support using only polymer fibers in the form of tubes having an inner diameter of 1 mm was prepared. To prepare a separator layer, 10 wt% of polyvinylidene difluoride, 65 wt% of N-methylpyrrolidone, and 25 wt% of polyvinylpyrrolidone were mixed to prepare a solution, and the solution was spun on the outer surface of the support. After application, the film was immersed in water to induce phase transition to prepare a hollow fiber separator having a membrane layer of 0.1 micrometers of voids and a thickness of 200 micrometers, and then measured electrical resistance and tensile strength. The hollow fiber membrane thus prepared was cut to 18 cm in length, the support layer was exposed, and the electrical resistance of both ends of the hollow fiber membrane was measured. The electrical resistance was infinite (∞) Ω-cm, which showed no electrical conductivity. The strength was 76 N / mm ² and measured at a level of 1/5 compared with Examples 1 to 2.

Existing hollow fiber membranes are difficult to apply to high pressure processes due to low mechanical strength, and it is impossible to separate mixtures using electrical properties because they cannot be supplied with electricity. The present invention overcomes the limitations of using commercially obtainable carbon fiber in the field of hollow fiber membranes and industrially, by imparting a function that could not be realized in the existing hollow fiber membranes, can withstand high pressure, and Excitation hollow fiber membranes were manufactured to enable their widespread industrial application and deployment.

<Description of Major Symbols in Drawing>
1: separator layer
2: polymer fiber yarn
3: carbon fiber yarn
4: support
11: braiding device
12: carbon fiber bobbin
13: polymer fiber bobbin

Claims (14)

In the hollow fiber membrane prepared by strengthening with a support,
A hollow fiber membrane comprising: a support reinforced with carbon fiber, and a separator layer formed on the support surface The hollow fiber separation membrane of claim 1, wherein the support reinforced with carbon fiber is a support prepared by braiding a mixture of carbon fiber and polymer fiber. The hollow fiber separation membrane according to claim 1, wherein the support reinforced with carbon fiber is a support prepared by braiding only carbon fiber. The hollow fiber separation membrane according to claim 1, wherein the carbon fiber is made of carbon fiber prepared by using one of polyacrylonitrile series, rayon series, petroleum and coal pitch series as precursors. The hollow fiber separation membrane according to claim 1, wherein the carbon fiber has a diameter of a single filament in the range of 1 to 20 micrometers. The hollow fiber separation membrane according to claim 1, wherein the support has an inner diameter of 1 to 4 mm and an outer diameter of 1.5 to 5 mm. The hollow fiber separation membrane of claim 1, wherein the separation membrane layer is formed on an inner wall side or an outer wall side of the support. The hollow fiber separation membrane of claim 1, wherein the hollow fiber separation membrane is a water treatment membrane, a gas separation membrane, a pervaporation membrane, or a vapor permeation membrane. The hollow fiber membrane of claim 1, wherein the membrane layer is one or more of a polymer, a metal, and a ceramic material. The hollow fiber separation membrane according to claim 2, wherein the polymer fiber is one or more of polypropylene, polyethylene, polyester, nylon, aramid, and teflon. The hollow fiber separation membrane of claim 9, wherein the polymer is one or more of polymers capable of forming a membrane layer by using a phase transition method, a diffusion induction phase separation method, and a thermal induction phase separation method. The hollow fiber separation membrane of claim 9, wherein the metal is one or more of nickel, stainless steel, titanium, aluminum, iron, and copper. The hollow fiber separation membrane of claim 9, wherein the ceramic is one or more of alumina, silica, titania, zirconia, antimony oxide, indium oxide, and cobalt oxide. The hollow fiber separation membrane according to claim 10, wherein the polymer fiber is made of 100 to 500 denier filaments.

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