KR102028534B1 - Fluid exchange membrane, method for preparation thereof and fluid exchange membrane module comprising the fluid exchange membrane - Google Patents

Abstract

Fluid exchange membrane according to an embodiment of the present invention is a porous membrane having a hydrophilic functional group on the surface, when the thickness is 50㎛ moisture permeability in the thickness direction of 300 to 1000 g / m ² h and tensile strength of 5 to 50 MPa Have
The fluid exchange membrane may have excellent mechanical strength and excellent water permeation performance to provide a high performance fluid exchange membrane module. The fluid exchange membrane module can be applied to various devices such as fuel cells or air conditioners to improve the performance of the device and to reduce the size and weight of the device.

Description

FLUID EXCHANGE MEMBRANE, METHOD FOR PREPARATION THEREOF AND FLUID EXCHANGE MEMBRANE MODULE COMPRISING THE FLUID EXCHANGE MEMBRANE}

The present invention relates to a fluid exchange membrane, a method for producing the same, and a fluid exchange membrane module including the fluid exchange membrane. More specifically, a fluid exchange membrane having excellent mechanical strength and water permeation performance, and a method for producing the same and a fluid including the fluid exchange membrane It relates to an exchange membrane module.

A fuel cell is a power generation type battery which produces electricity by combining hydrogen and oxygen. Unlike general chemical cells such as batteries and accumulators, fuel cells can continue to produce electricity as long as hydrogen and oxygen are supplied. Fuel cells have no heat loss and are twice as efficient as internal combustion engines. In addition, pollutant emissions are low because chemical energy generated by the combination of hydrogen and oxygen is converted directly into electrical energy. Therefore, the fuel cell is not only environmentally friendly but also has an advantage of reducing anxiety about resource depletion due to increased energy consumption. Such fuel cells are classified into polymer electrolyte fuel cells (PEMFCs), phosphoric acid fuel cells (PAFCs), molten carbonate fuel cells (MCFCs), and solid oxide fuel cells, depending on the type of electrolyte used. SOFC), alkaline fuel cell (AFC), and the like. Each of these fuel cells operates on essentially the same principle, but differs in the type of fuel used, operating temperature, catalyst, electrolyte, and the like. Among them, the polymer electrolyte fuel cell is known to be most promising not only in small stationary power generation equipment but also in transportation systems because it can operate at a lower temperature than other fuel cells and can be miniaturized due to its high power density.

One of the most important factors in improving the performance of a polymer electrolyte fuel cell is supplying a certain amount of water to a polymer electrolyte membrane (PEM) of a membrane-electrode assembly (MEA) (Polymer Eletrolyte Membrane or Proton Exchange Membrane (PEM)). This is to maintain the moisture content. This is because power generation efficiency is drastically reduced when the polymer electrolyte membrane is dried. A method of humidifying a polymer electrolyte membrane includes 1) a bubbler humidification method in which water is supplied to a pressure vessel and a target gas is passed through a diffuser to supply moisture, and 2) the amount of water supplied for a fuel cell reaction is determined. And a direct injection method of supplying water directly to the gas flow pipe through the solenoid valve, and 3) a humidification method of supplying water to the fluidized bed of gas using a polymer membrane. Among them, a humidification membrane system for humidifying a polymer electrolyte membrane by providing water vapor to a gas supplied to the polymer electrolyte membrane by using a membrane that selectively permeates only water vapor contained in the exhaust gas is advantageous in that the humidifier can be reduced in weight and size.

However, in the case of the humidification membrane method, since the moisture is supplied to the gas fluidized bed by the diffusion and condensation of moisture due to the partial pressure difference of the moisture on both sides of the humidification membrane, there are many limitations in improving the performance of the humidification membrane method. .

Republic of Korea Patent Publication No. 10-2009-0013304 (published: 2009.02.05)

It is an object of the present invention to provide a fluid exchange membrane and a method for producing the same having excellent mechanical strength and water permeation performance.

Another object of the present invention is to provide a fluid exchange membrane module including the fluid exchange membrane.

In order to achieve the above object, the fluid exchange membrane according to an embodiment of the present invention is a porous membrane having a hydrophilic functional group on the surface, when the thickness is 50㎛ moisture permeability in the thickness direction of 300 to 1000 g / m ² h and 5 Tensile strength of from 50 MPa.

The porous membrane may be, for example, in the form of a hollow fiber membrane or a flat membrane. In addition, the porous membrane is, for example, polysulfone, polyethersulfone, polyarylene sulfone, polyarylene ether sulfone, polyimide, polyetherimide, polyamideimide, polyvinyl alcohol, polyacrylonitrile, tetra Fluoroethylene-perfluoro-dioxa-methyl-octysulfonic acid copolymers, copolymers thereof or mixtures thereof.

The hydrophilic functional group may be, for example, a sulfonic acid group, a phosphoric acid group, a hydroxyl group, a carboxyl group, a carbonic acid group, a nitric acid group or a mixture thereof.

A method of manufacturing a fluid exchange membrane according to another embodiment of the present invention includes the step of immersing the porous membrane in an acidic solution.

The manufacturing method may further comprise providing a porous membrane prior to said step.

Dipping the porous membrane in an acidic solution may be performed under a temperature of 30 to 100 ° C., or by immersing the porous membrane in an acidic solution for 0.5 to 100 hours. The acidic solution may be, for example, an acidic solution of 0.1 to 10 molar concentrations. In addition, as said acidic solution, sulfuric acid, chlorosulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, or a mixture thereof can be used, for example.

Fluid exchange membrane module according to another embodiment of the present invention comprises at least two pairs of the fluid inlet and the fluid outlet is formed; And the first fluid disposed in the case and disposed so that the first fluid flowing between the pair of fluid inlets and the fluid outlet in a driving state does not directly contact the second fluid flowing between the other pair of fluid inlets and the fluid outlet. A fluid exchange membrane.

In one example, the fluid exchange membrane may be in the form of a hollow fiber membrane. In this case, in the fluid exchange membrane module, the case and the fluid exchange membrane may be disposed such that the first fluid flows through the hollow of the hollow fiber membrane and the second fluid flows through the hollow fiber bundle of the hollow fiber membrane. The case may include an inlet case in which a fluid inlet is formed, an outlet case in which a fluid outlet is formed, and a connection case in which a fluid inlet and a fluid outlet are formed to enable the driving as described above. The case may have a structure in which the inlet case and the outlet case are connected by a connection case. In addition, the fluid exchange membrane may be disposed such that one end of the hollow fiber bundle in the longitudinal direction is located on the inflow case side, and the other end is located on the discharge case side.

On the other hand, it may further include a potting portion for fixing the hollow fiber bundles on both ends of the connection case.

In another example, the fluid exchange membrane may be in the form of a flat membrane. In this case, in the fluid exchange membrane module, the case and the fluid exchange membrane may be disposed such that the first fluid flows along one surface of the flat membrane and the second fluid flows along the other surface of the flat membrane in a driving state. The case has an internal space to enable such a drive, and a structure in which two pairs of fluid inlets and fluid outlets are formed on the surface to supply fluid from the outside of the case to the interior space and to discharge the fluid from the interior space to the exterior of the case. It can have The fluid exchange membrane has a periphery of which is divided into an inner space of the case by contacting the inner wall of the case, and one of the divided inner spaces is connected to a pair of fluid inlets and a fluid outlet, and the other of the divided internal spaces. One space may be disposed in the case to be connected to the other pair of fluid inlets and fluid outlets.

The fluid exchange membrane module may be, for example, a humidification module, a heat exchange module, a gas separation module, or a water treatment module.

Hereinafter, the present invention will be described in more detail.

Fluid exchange membrane according to an embodiment of the present invention is a porous membrane having a hydrophilic functional group on the surface. If two fluids exist between the porous membranes forming the fluid exchange membrane, the two fluids may selectively exchange specific fluids contained in the fluid through the fluid exchange membrane. As shown in FIG. 1, pores 13 may be present in the porous membrane 10. In addition, the pores may be, for example, capable of selectively permeating or adsorbing a specific fluid. In the drawings of the present specification, in order to explain the structure of the porous membrane, pore and hydrophilic functional groups are schematically represented for convenience. Therefore, the pore morphology, pore distribution, pore size and distribution form of hydrophilic functional groups of the actually prepared porous membrane may be variously represented.

The hydrophilic functional group 14 may be present on the surface of the porous membrane as shown in FIG. 1. In the present specification, the surface of the porous membrane is a surface in contact with a solvent when the porous membrane is impregnated with a solvent, as opposed to an inside which is a part which does not contact the solvent when the porous membrane is impregnated with a solvent.

Thus, the hydrophilic functional group 14 may be present on the surface 11a of the pores of the porous membrane and the outer wall 11b of the porous membrane as shown in FIG. 1. The porous membrane may have a moisture permeability of more than the moisture permeability due to the partial pressure difference of the moisture on both surfaces of the porous membrane by the presence of a hydrophilic functional group on its surface. Porous membrane in fluid-exchange membrane having a hydrophilic functional group to the surface in one example is when the thickness of 50㎛ a moisture permeability in the thickness direction be equal to or greater than 300g / m ² h or more, 310g / m ² h or more than 320g / m ² h .

The water vapor transmission rate is the water vapor transmission rate in the thickness direction measured according to ASTM E96 / E96M-12 for a porous membrane specimen having a thickness of 50 μm. The upper limit of the moisture permeability of the fluid exchange membrane is not particularly limited as long as the mechanical strength of the fluid exchange membrane is maintained at an appropriate level. The fluid exchange membrane may have a thickness of, for example, 1000 g / m ² h or less, 800 g / m ² h or less, 500 g / m ² h or less, 400 g / m ² h or less, or 370 g / m ² h or less under the above conditions. By having moisture permeability in the direction it is possible to maintain an appropriate level of mechanical strength.

In addition, the fluid exchange membrane is formed to distribute the hydrophilic functional group on the surface of the porous membrane can also ensure excellent mechanical strength. If there is an equivalent level of hydrophilic functional groups on the surface and inside of the porous membrane, it is not possible to provide a fluid exchange membrane having an appropriate level of mechanical strength due to swelling caused by moisture. Accordingly, the fluid exchange membrane may be formed such that a large amount of hydrophilic functional groups are present on the surface of the porous membrane. That is, a trace amount of hydrophilic functional groups may be present or not present in the porous membrane of the fluid exchange membrane. However, if the material forming the porous membrane is a material having a hydrophilic functional group, there may be a considerable amount of hydrophilic functional groups inside the porous membrane, although less than the surface.

In one example, the fluid exchange membrane may have an excellent tensile strength of at least 5 MPa, at least 7 MPa, or at least 8 MPa by forming a larger amount of hydrophilic functional groups on the surface of the porous membrane. The tensile strength refers to a value obtained by pulling both sides of the specimen cut to a predetermined size in opposite directions and dividing the force at the time of fracture of the specimen by the fracture area, and the specific measuring method may refer to the embodiment. The upper limit of the tensile strength of the fluid exchange membrane is not particularly limited, and may be, for example, 50 MPa or less, 30 MPa or less, 20 MPa or less, or 15 MPa or less.

The fluid exchange membrane may be formed by acid treatment of the porous membrane so that a greater amount of hydrophilic functional groups are present on the surface of the porous membrane. A specific method of manufacturing the fluid exchange membrane may refer to the following description.

The porous membrane may be in the form of a hollow fiber membrane or a flat membrane, for example.

In one example, the porous membrane 20 in the form of a hollow fiber membrane may be a bundle of hollow fibers 25, as shown in FIG. 2. When the porous membrane 20 of the hollow fiber 25 bundle as shown in FIG. 2 is used as the fluid exchange membrane, pores 23 are present in the porous membrane of the hollow fiber bundle, and the porous membrane 20 of the bundle of hollow fiber 25 is present. The hydrophilic functional group 24 which exists in the surface of () can be used. The hydrophilic functional group 24 may be present on the surface 21a of the pores of the hollow yarns, the outer wall 21b of the hollow yarns, and the inner wall 21c of the hollow yarns, as shown in FIG. 2, if the hollow yarns are impregnated in the solvent. . When the fluid exchange membrane is in the form of a hollow fiber membrane, the above-described moisture permeability is the moisture permeability from the outer wall 21b of the hollow yarn of FIG. 2 to the inner wall 21c of the hollow yarn or from the inner wall 21c of the hollow yarn to the outer wall 21b of the hollow yarn. It means moisture permeability. In addition, the thickness which is a measurement condition of moisture permeability means the shortest distance between the outer wall 21b and the inner wall 21c of a hollow yarn. In the present specification, the hollow is represented as a circle, but the hollow shape of the hollow yarn actually manufactured may be other than circular.

The porous membrane in the form of a hollow fiber membrane may have a high density of the porous membrane between the hollows 26 of the hollow yarns and the spaces 27 between the hollow fiber bundles, thereby providing a high performance fluid exchange membrane.

In another example, the porous membrane 30 in the form of a flat membrane may be a membrane having both flat surfaces, as shown in FIG. 3. When the porous membrane 30 in the form of a flat membrane as shown in FIG. 3 is used as the fluid exchange membrane, pores 33 are present in the flat membrane, and hydrophilic functional groups 34 are present on the surface 31. The hydrophilic functional group 34 may be present on the surface 31a of the pores of the flat membrane and the outer wall 31b of the flat membrane, which is a surface which may be in contact with the solvent, as shown in FIG. 3.

The porous membrane can be used without limitation, as long as it can generate hydrophilic functional groups by acid treatment. Among them, materials of the porous membrane which can be employed to generate hydrophilic functional groups by acid treatment include, for example, polysulfone; Polyethersulfones; Polyarylene sulfones such as polyphenylene sulfone and the like; Polyarylene ether sulfones such as polyphenylene ether sulfone and the like; Polyimide; Polyetherimide; Polyamideimide; Polyvinyl alcohol; Polyacrylonitrile; Tetrafluoroethylene-perfluoro-dioxa-methyl-octysulfonic acid copolymer (tetrafluoroethylene-perfluoro-3,6-dioxa-4-methyl-7-octenesulfonic acid copolymer); Copolymers thereof; Or mixtures thereof. In the above, their copolymers refer to copolymers obtained by polymerizing monomers used to synthesize two or more selected polymers, and a mixture thereof means a mixture in which two or more selected polymers are physically mixed.

In one example, the polysulfone, polyethersulfone, polyarylene sulfone, polyarylene ether sulfone, and the like can easily form hydrophilic functional groups on the surface by acid treatment, and have excellent water permeability in a simple process. May provide a membrane. In addition, the materials of the polymers can be obtained inexpensively, which is suitable for economic mass production of fluid exchange membranes.

The hydrophilic functional group of the porous membrane is formed on the surface of the porous membrane by acid treatment of the porous membrane. Thus, hydrophilic functional groups can be present in various ways depending on the acid and the material of the porous membrane. Examples of such hydrophilic functional groups include sulfonic acid groups (-SO ₃ H), phosphoric acid groups (-O-PO ₃ H ₂ ), hydroxyl groups (-OH), carboxyl groups (-COOH), and carbonic acid groups (-O-CO ₂ H), nitrate groups (-O-NO ₂ ) or mixtures thereof and the like.

The fluid exchange membrane may be applied to a structure commonly employed in the art in addition to the above-described structure.

A method of manufacturing a fluid exchange membrane according to another embodiment of the present invention includes the step of immersing the porous membrane in an acidic solution.

If the polymer is acid treated and a porous membrane is prepared from the acid treated polymer, and the above method is not employed, hydrophilic functional groups are generated at the same level on the surface and inside of the porous membrane. As a result, a fluid exchange membrane is provided in which mechanical strength is reduced due to swelling of the membrane by moisture.

Therefore, the method of manufacturing the fluid exchange membrane may provide a fluid exchange membrane in which a large amount of hydrophilic functional groups are formed on the surface of the inner relative surface by employing a method of forming a porous membrane and then immersing the porous membrane in an acidic solution. Such a fluid exchange membrane can exhibit excellent moisture permeability and mechanical strength.

Therefore, the method of manufacturing the fluid exchange membrane may further include providing a porous membrane before the step.

In one example, the porous membrane may be provided by purchasing a commercially available product. As such, if a commercially available one is used as the porous membrane, the method of manufacturing the fluid exchange membrane may be performed in a separate process separate from the method of manufacturing the porous membrane.

In another example, the provision of the porous membrane may be performed by preparing the porous membrane by a method known in the art. As described above, when the porous membrane is manufactured and used, a device capable of immersing the porous membrane in an acidic solution may be added to an existing porous membrane manufacturing process to integrate the manufacturing method of the fluid exchange membrane with the manufacturing method of the porous membrane. have.

Since the method of manufacturing the fluid exchange membrane may use a porous membrane such as a conventional hollow fiber membrane or a flat membrane, or may utilize a conventional manufacturing apparatus of a porous membrane such as a hollow fiber membrane or a flat membrane, thereby producing a fluid exchange membrane having excellent performance. There is an advantage of easy integration with technology.

When the porous membrane is immersed in an acidic solution, hydrophilic functional groups are produced on the surface of the porous membrane. The applicant expects that the end of the polymer constituting the porous membrane reacts with an acid to produce the hydrophilic functional group.

Process conditions of the step of immersing the porous membrane in the acidic solution may be controlled according to the type of the porous membrane, the type and concentration of the acidic solution.

In one example, the step of immersing the porous membrane in the acidic solution may be performed at a temperature of 30 to 100 ℃, 50 to 100 ℃ or 70 to 100 ℃. It is possible to generate an appropriate amount of hydrophilic functional groups on the surface of the porous membrane in the temperature range without affecting the properties of the porous membrane. And the porous membrane may be immersed in an acidic solution for 0.5 to 100 hours, 0.5 to 50 hours, 0.5 to 20 hours, 0.5 to 10 hours, 0.5 to 5 hours or 1 to 3 hours, for example. The time for immersing the porous membrane in the acidic solution can be appropriately controlled according to the process temperature within the above range. As a result, it is possible to provide a fluid exchange membrane in which hydrophilic functional groups are generated on the surface without deteriorating the physical properties of the porous membrane.

The acidic solution may be prepared at an appropriate concentration to produce a hydrophilic functional group in the polymer forming the porous membrane without affecting the physical properties of the porous membrane. In one example, the concentration of the acidic solution may be controlled to about 0.1 to 10 M (molar concentration) or 0.1 to 7 M to provide a high performance fluid exchange membrane.

As the acidic solution, a conventionally usable acidic solution may be used without limitation. Examples of such acidic solutions include sulfuric acid, chlorosulfuric acid, hydrochloric acid, nitric acid, phosphoric acid or mixtures thereof.

The method of manufacturing the fluid exchange membrane may further include drying the porous membrane having a hydrophilic functional group on the surface from the acidic solution after immersing the porous membrane in the acidic solution. The temperature and time for drying the porous membrane having hydrophilic functional groups on the surface can be appropriately controlled in consideration of the boiling point of the acidic solution and other solvents used.

The method of manufacturing the fluid exchange membrane may further include a step commonly performed in the art, in addition to the above-described steps.

The fluid exchange membrane module according to another embodiment of the present invention includes a case and the fluid exchange membrane embedded in the case.

The fluid exchange membrane module is a device in which two fluids are driven to exchange fluids such as water or heat through a fluid exchange membrane existing between at least two fluids. Therefore, at least two pairs of fluid inlets and fluid outlets may be formed in the case. In addition, the fluid exchange membrane may be disposed in the case so that the two fluids do not directly contact. That is, in the driving state of the fluid exchange membrane module, the fluid exchange membrane is disposed so that the first fluid flowing between any one pair of fluid inlet and the fluid outlet does not directly contact the second fluid flowing between the other pair of fluid inlet and the fluid outlet. It can be placed inside. In this specification, the direct contact between the first fluid and the second fluid does not mean a state in which the first fluid and the second fluid are completely separated from each other, but a porous membrane exists between the first fluid and the second fluid so that the first fluid and the second fluid do not directly contact each other. It means a state in which the fluid and the second fluid cannot be freely mixed.

The structure constituting the fluid exchange membrane module can be controlled according to the shape of the fluid exchange membrane.

In one example, if the fluid exchange membrane is formed of a porous membrane in the form of a hollow fiber membrane as shown in FIG. 2, one of two fluids passes through the hollow fiber hollow, and the other fluid passes between the hollow fiber bundles. Exchange membrane modules can be constructed.

The fluid exchange membrane module 40 has an inlet case 41 in which the fluid inlet 45a is formed, an outlet case 42 in which the fluid outlet 45b is formed, and a fluid inlet 46a and a fluid outlet, as shown in FIG. 4. It includes a connection case 43 is formed 46b, it may include a case having a structure connecting the inlet case 41 and the discharge case 42 to the connection case 43. In addition, the fluid exchange membrane module 40 is positioned at one end of the fluid exchange membrane 44 in the longitudinal direction P of the hollow fiber bundle at the inlet case 41 side, and the other end at the discharge case 42 side. It may have a structure arranged so as to.

The connection case 43 may further include a porting portion 47 at both ends of the connection case 43 to fix the hollow fiber bundle as shown in FIG. The potting portion 47 fills the voids between the hollow fiber bundles while binding the hollow fiber bundles to prevent the fluid passing between the hollow fiber bundles from entering the hollow. The material of the potting part 47 may be used without limitation.

The structure of the fluid exchange membrane module 40 is not limited to the above structure, and a structure employed in a module using a porous membrane in the form of a hollow fiber membrane may be appropriately applied.

In another example, if the fluid exchange membrane is formed of a porous membrane in the form of a flat membrane as shown in FIG. 3, the fluid exchange membrane module may be configured such that a flat membrane exists between two fluids so that the two fluids flow along opposite sides of the flat membrane. .

The fluid exchange membrane module 50 has an internal space 55 as shown in FIG. 5, supplies fluid from the case 51 to the internal space 55, and externally the case 51 in the internal space 55. Two pairs of fluid inlets 53a and 54a and fluid outlets 53b and 54b may include a case 51 having a structure formed on a surface thereof so as to discharge the furnace fluid. In addition, the fluid exchange membrane module 50 may include a fluid exchange membrane 52 disposed so that the circumference of the flat membrane 52 contacts the inner wall of the case 51 and divides the internal space 55 of the case as shown in FIG. 5. have. At this time, the fluid exchange membrane 52 is connected to a pair of the fluid inlet 53a and the fluid discharge port 53b of any one of the divided internal spaces 55a, and the other one of the divided internal spaces 55b ) May be disposed in the case so as to be connected to the other pair of fluid inlet 54a and fluid outlet 54b. As a result, the fluid exchange membrane module 50 may be configured to prevent the two kinds of fluids from coming into direct contact with each other due to the fluid exchange membrane 52 and to allow fluid exchange such as water between the two kinds of fluids. In addition, the flat membrane type fluid exchange membrane 52 may include wrinkles, that is, the flat membrane 52 may be folded down to increase the contact area between the flat membrane 52 and the fluid. In the present specification, the term bifurcating is a term having a meaning of dividing one space into two spaces, and does not require that the size or area of the two spaces be the same, and is a term distinguished from the bisection.

Even in the case of a fluid exchange membrane module including a fluid exchange membrane formed of the porous membrane in the form of a flat membrane, the structure thereof is not limited to the above structure, and structures employed in a module using the porous membrane in the form of a flat membrane may be applied.

The fluid exchange membrane module has excellent fluid exchange performance such as moisture between two or more fluids, and thus can be applied to various fields. The fluid exchange membrane module may be used as, for example, a humidification module, a heat exchange module, a gas separation module, a water treatment module, or the like.

In one example, the fluid exchange membrane module may be applied as a humidification module of a fuel cell. The fluid exchange membrane module can be applied as a humidification module of a fuel cell by employing a method known in the art. In addition, it is possible to appropriately control the structure of the fluid exchange membrane module in accordance with the capacity of the fuel cell. For example, a module having a porous membrane in the form of a hollow fiber membrane may be used in a fuel cell system having a high capacity of 100 kW or more requiring high integration.

Exemplary fluid exchange membranes may have good mechanical strength and good water permeation performance to provide high performance fluid exchange membrane modules. The fluid exchange membrane module may be applied to various devices such as fuel cells or air conditioners to improve the performance of the device and to reduce the size and weight of the device.

1 is a cross-sectional view schematically showing a part of a porous membrane according to one embodiment of the present invention.
2 is a cross-sectional view schematically showing a part of the porous membrane in the form of a hollow fiber membrane according to an embodiment of the present invention.
3 is a cross-sectional view schematically showing a part of the porous membrane in the form of a flat membrane according to an embodiment of the present invention.
4 is a sectional view schematically showing a fluid exchange membrane module according to an embodiment of the present invention.
5 is a cross-sectional view schematically showing a fluid exchange membrane module according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

[ Production Example : Of the fluid exchange membrane  Produce]

( Comparative example  One)

20% by weight of polysulfone resin, 10% by weight of pore-forming additives and 70% by weight of solvent (dimethylacetamide (DMAC)) were added to a reaction vessel and prepared for dope to prepare a hollow fiber membrane by stirring at a temperature of 70 ° C for 6 hours. . In addition, as a core coagulating solution for wet and dry spinning, 50 wt% of water and DMAC were respectively mixed. The dope and the coagulant were injected into a double tubular nozzle to prepare polysulfone hollow fiber (outer diameter 900 μm, inner diameter 800 μm), and a fluid exchange membrane in the form of a hollow fiber membrane having 8,000 pieces as one bundle was prepared.

( Comparative example  2)

The same polysulfone resin used in the sulfuric acid solution of 5 M (molarity) in the same manner as in Comparative Example 1 was stirred at 80 ° C. for 5 hours and then dried to obtain a resin into which a sulfuric acid functional group was introduced. A fluid exchange membrane was prepared in the same manner as in Comparative Example 1 except that the resin having the sulfuric acid functional group introduced therein instead of the polysulfone resin was used in the comparison.

( Example  One)

The fluid exchange membrane of Comparative Example 1 was immersed in 0.5 M sulfuric acid solution for 2 hours. At this time, the temperature of the acidic solution was maintained at 80 ℃. Subsequently, the membrane was removed from an acidic solution, washed with distilled water, and dried at a temperature of 80 ° C. to prepare a fluid exchange membrane.

( Example  2)

A fluid exchange membrane was prepared in the same manner as in Example 1, except that 5 M sulfuric acid solution was used as the acid solution in Example 1.

[ Experimental Example : Of the fluid exchange membrane  Property measurement]

Physical properties of the fluid exchange membranes prepared in Examples and Comparative Examples were measured, and the results are shown in Table 1 below.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Breathable ⁽¹⁾
(Unit: g / m ² h) 250 380 330 360 Tensile Strength ⁽²⁾
(Unit: MPa) 10 3 10 9 Humidification Performance ⁽³⁾
(Unit: ℃) 55 62 60 61

(1) Water vapor permeability test: The water vapor permeability in the thickness direction of the hollow fiber was measured according to ASTM E96 / E96M-12 for a membrane having a thickness of 50 μm between the hollow fiber hollow and the outer wall of the hollow fiber.

(2) Mechanical strength test: After the hollow fiber bundles were cut to a length of 100 mm, both ends of the longitudinal direction of the hollow fiber bundles were pulled in opposite directions using a UTM apparatus. The force acting at the break of the hollow fiber bundle was measured, and the force was divided by the fracture area to define the tensile strength.

(3) Humidification performance test: 50g / sec of dry air is introduced into the space between the hollow and hollow fiber bundles of the hollow fiber bundles, and the outside of the hollow fiber bundles is fixed at a temperature of 70 ° C. and a humidity of 90%, and the hollow fiber bundles The hollow of was fixed at a temperature of 40 ° C. and a humidity of 10% to perform gas-gas humidification. The humidification performance was defined as a value converted into dew points by measuring the temperature and humidity at the point where air flowing through the hollow of the hollow fiber is humidified.

The fluid exchange membranes of Examples 1 and 2 showed excellent moisture permeability and humidification performance compared to Comparative Example 1. However, Comparative Example 2 in which the resin for preparing the fluid exchange membrane was treated with acid showed excellent moisture permeability compared to Comparative Example 1, but exhibited a very poor tensile strength compared to Comparative Example 1 due to swelling caused by moisture. In contrast, the fluid exchange membranes of Examples 1 and 2 were found to maintain the same tensile strength as Comparative Example 1, despite the improved water permeation performance.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

10 porous membrane
11 Surface of Porous Membrane
11a the surface of the pores of the porous membrane
11b Outer Wall of Porous Membrane
12 Inside of porous membrane
13 pore
14 hydrophilic functional groups
20 Porous membranes in the form of hollow fiber membranes
21 Surface of porous membrane in the form of hollow fiber membrane
21a Porous surface of porous membrane in the form of hollow fiber membrane
21b Outer wall of porous membrane in the form of hollow fiber membrane
Inner wall of porous membrane in the form of 21c hollow fiber membrane
22 Inside the porous membrane in the form of a hollow fiber membrane
23 perforations
24 hydrophilic functional groups
25 hollow fiber
26 hollow
27 Space between hollow fiber bundles
30 flat membrane porous membrane
31 Surface of the porous membrane in the form of flat membrane
31a The surface of the pores of the porous membrane in the form of flat membrane
31b outer wall of the porous membrane in the form of flat membrane
32 The inside of the porous membrane in the form of flat membrane
33 pore
34 hydrophilic functional groups
40 Fluid Exchange Membrane Module
41 Inflow Case
42 Output Case
43 connection case
44 Fluid exchange membrane
45a Fluid Inlet
45b fluid outlet
46a fluid inlet
46b fluid outlet
47 Potting Part
50 Fluid Exchange Membrane Module
51 cases
52 Fluid Exchange Membrane
53a fluid inlet
53b fluid outlet
54a fluid inlet
54b fluid outlet
55 Interior Space
55a space in one of two subdivided interior spaces
55b the other of the divided internal spaces

Claims (17)

A fluid exchange membrane capable of selectively permeating only water vapor,
A hydrophilic functional group is provided only on the surface after being formed of a material having no hydrophilic functional group to thereby include a porous membrane in which the hydrophilic functional group is present only on the surface and not inside,
The material without a hydrophilic functional group is polysulfone, polyethersulfone, polyarylene sulfone, polyarylene ether sulfone, polyimide, polyetherimide, polyamideimide, polyvinyl alcohol, polyacrylonitrile without hydrophilic functional groups , Tetrafluoroethylene-perfluoro-dioxa-methyl-octysulfonic acid copolymer, a copolymer thereof or a mixture thereof,
Fluid exchange membrane.
The method of claim 1,
The porous membrane is a fluid exchange membrane in the form of a hollow fiber membrane or flat membrane.
The method of claim 1,
When the thickness is 50 μm, the water vapor transmission rate in the thickness direction is 300 to 1000 g / m ² h,
Tensile strength of 5 to 50 MPa,
Fluid exchange membrane.
The method of claim 1,
Wherein said hydrophilic functional group is a sulfonic acid group, a phosphoric acid group, a hydroxy group, a carboxyl group, a carbonic acid group, a nitric acid group or a mixture thereof.
In the manufacturing method of the fluid exchange membrane which can selectively permeate only water vapor,
Providing a porous membrane formed of a material having no hydrophilic functional groups, and
In order to ensure that a hydrophilic functional group is not present inside the porous membrane but only on the surface thereof, the porous membrane is immersed in an acidic solution at a temperature of 30 to 100 ° C., and then washed and dried to impart a hydrophilic functional group to the surface of the porous membrane. Including the steps of:
The material without a hydrophilic functional group is polysulfone, polyethersulfone, polyarylene sulfone, polyarylene ether sulfone, polyimide, polyetherimide, polyamideimide, polyvinyl alcohol, polyacrylonitrile without hydrophilic functional groups , Tetrafluoroethylene-perfluoro-dioxa-methyl-octysulfonic acid copolymer, a copolymer thereof or a mixture thereof,
Method for producing a fluid exchange membrane.
delete delete The method of claim 5,
The step of producing a fluid exchange membrane comprising immersing the porous membrane in an acidic solution for 0.5 to 100 hours.
The method of claim 5,
The step of producing a fluid exchange membrane comprising immersing the porous membrane in an acidic solution of 0.1 to 10 molar concentration.
The method of claim 5,
A method of producing a fluid exchange membrane using sulfuric acid, chlorosulfuric acid, hydrochloric acid, nitric acid, phosphoric acid or a mixture thereof as the acidic solution.
A case in which at least two pairs of fluid inlets and fluid outlets are formed; And a first fluid embedded in the case and disposed such that the first fluid flowing between the pair of fluid inlets and the fluid outlet in a driving state does not directly contact the second fluid flowing between the other pair of fluid inlets and the fluid outlet. Fluid exchange membrane module comprising a fluid exchange membrane according to claim 1.
The method of claim 11,
And the fluid exchange membrane is in the form of a hollow fiber membrane, wherein the first fluid flows through the hollow of the hollow fiber membrane, and the second fluid flows between the hollow fiber bundles of the hollow fiber membrane.
The method of claim 12,
The case includes an inlet case in which the fluid inlet is formed, an outlet case in which the fluid outlet is formed, and a connection case in which the fluid inlet and the fluid outlet are formed, and the case connects the inlet case and the outlet case to the connection case. A fluid exchange membrane module having a structure, wherein the fluid exchange membrane is disposed in the case such that one end in the longitudinal direction of the hollow fiber bundle is located on the inlet case side and the other end is located on the outlet case side.
The method of claim 13,
Fluid exchange membrane module comprising a potting portion for fixing the hollow fiber bundles on both ends of the connection case.
The method of claim 11,
And a case and a fluid exchange membrane such that the fluid exchange membrane is in the form of a flat membrane, the first fluid flows along one surface of the flat membrane, and the second fluid flows along the other surface of the flat membrane.
The method of claim 15,
The case has an internal space, and has a structure in which two pairs of fluid inlets and fluid outlets are formed on the surface to supply fluid from the outside of the case to the internal space, and discharge the fluid from the internal space to the outside of the case,
The fluid exchange membrane is divided into two inner spaces of the case in contact with the inner wall of the case, and any one of the divided inner spaces is connected to a pair of fluid inlets and fluid outlets, and the other one of the divided internal spaces. The space of the fluid exchange membrane module is disposed in the case to be connected to the other pair of fluid inlet and fluid outlet.
The method of claim 11,
The fluid exchange membrane module may be a humidification module, a heat exchange module, a gas separation module, or a water treatment module.

Images