KR20170090193A - Liquid stream inducing type polymer membrane, method of preparing the same and fuel cell comprising the same - Google Patents

Abstract

The present invention relates to a liquid stream inducing type polymer membrane, a method for preparing the same and a fuel cell comprising the same. A liquid stream inducing type polymer membrane capable of adjusting a stream of liquids is manufactured by using a plurality of prism patterns having physical symmetry and chemical asymmetry and is applied to an electrolyte membrane for a fuel cell, thereby adjusting the water content of the electrolyte membrane. Accordingly, problems that controlling the water content of an electrolyte membrane is difficult and cell resistance is increased since the interface between an electrolyte membrane and an electrode is separated due to repeated hydration and dehydration processes can be solved.

Description

TECHNICAL FIELD The present invention relates to a liquid flow induction type polymer membrane, a method of manufacturing the same, and a fuel cell including the liquid flow induction type polymer membrane.

The present invention relates to a liquid flow induction type polymer membrane and a fuel cell including the polymer electrolyte membrane as a polymer electrolyte membrane.

In recent years, there has been a growing interest in the wetting and flow of directional liquids in terms of applications related to liquid flow control in microfluidics and collecting fields, and the wetting properties of liquids are predicted by modifying metal or polymer surface properties Research is actively underway to change to a more active and active form.

Conventional studies have been directed to the unidirectional wetting or flow of liquids over mostly physically asymmetric microstructures, which can be realized by using a nanostructure having a bent nanopillar or inclined nanorod type of inclination to achieve unidirectional wetting, Or anisotropic structures to implement directional liquid flow.

However, since the anisotropic structure as described above depends greatly on its characteristics and is not structurally stable and has to have a force applied to the liquid in order to move the entire surface of the liquid in a desired direction, anisotropy do.

Therefore, a directional liquid flow is being studied using the difference in surface contact angle, which is a phenomenon that occurs when a droplet interacts with a surface.

As shown in Fig. 1, the contact angle [theta] is determined by an equilibrium of a force acting between a solid, a liquid and a gas, and a contact angle difference occurring in one droplet means a difference in force, It can apply force to the liquid droplet, control the surface energy of the liquid droplet through external energy such as electric energy or heat energy, and adjust the direction of the droplet moving through the surface contact angle pattern.

Conventionally, for the contact angle larger or smaller than the ideal contact angle of the surface, the surface was roughened to form a pattern, and the droplet was regulated as the contact angle difference increased. However, the large contact angle history hindered the movement of the droplet.

As described above, although the larger the contact angle difference is advantageous in order to control the droplet, roughing the surface in order to increase the contact angle difference has a problem of contradiction which hinders the movement of the droplet.

On the other hand, as shown in the following reaction formula (1), the fuel cell reacts directly with hydrogen in the anode (-) and oxygen in the cathode (+) to generate water directly. Instead of converting the chemical energy of the fuel into thermal energy, Because it can be converted into energy, energy conversion efficiency is high at low temperature and is expected as future power generation system.

[Reaction Scheme 1]

An anode _{(-): H 2 → 2H} + + 2e -

Cathode (+): 1/2 .O ₂ + 2H ⁺ + 2e ^- → H ₂ O

As described above, compared to a power generation system in which fossil fuels such as petroleum and natural gas are combusted, the fuel cell generates power by reaction that does not generate carbon dioxide, and almost no nitrogen oxides or sulfur oxides, which are harmful substances, , There is little noise or vibration.

These fuel cells have a structure in which the electrolyte at the center is surrounded by two electrodes. Depending on the type of the electrolyte, a solid polymer type (PEFC or PEMFC), an alkali type (PAFC), a molten carbonate type (MCFC) SOFC). Since a dual solid polymer fuel cell uses a hydrogen ion (H ⁺ ) conductive polymer electrolyte membrane as an electrolyte, it can be used at room temperature and thus can be used as a power source for vehicles such as automobiles.

The most important component in a solid polymer type fuel cell is a cation exchange membrane. Until now, mainly a fluorine resin electrolyte membrane has been used, but a hydrocarbon electrolyte membrane has been researched and developed to improve physical properties such as heat resistance, mechanical strength and chemical stability .

However, in the case of a hydrocarbon-based electrolyte membrane, the hydrocarbon-based electrolyte membrane has a volume expansion characteristic due to humidification, and a portion where the hydrocarbon-based electrolyte membrane contacts the cathode due to H ₂ O generated at the cathode during driving the fuel cell including the hydrocarbon- There is a problem that the boundary of the portion where the volume expansion degree of the hydrocarbon-based electrolyte membrane is different is broken due to the difference of the volume expansion degree.

Further, when the fuel cell is operated at a high current, the reaction at each electrode of the fuel cell is accelerated, and the anode is dried.

Accordingly, there is a continuing need to develop a polymer membrane capable of controlling the moisture content itself, as an electrolyte membrane for a fuel cell, which can solve the problems occurring in a hydrocarbon-based electrolyte membrane when the fuel cell is driven.

U.S. Published Patent Application 2004-0191127 Korea Patent Publication No. 2010-0050423

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid flow induction type polymer membrane suitable for an electrolyte membrane of a fuel cell, Method.

Another object of the present invention is to provide a fuel cell including a liquid flow induction type polymer membrane according to various embodiments of the present invention.

According to an exemplary aspect of the present invention, a plate; And a liquid flow guide part integrally formed on one surface or both surfaces of the plate and guiding a one-way flow of the liquid in a direction of low hydrophilicity, wherein the liquid flow guide part has a plurality of prism patterns, Wherein the liquid flow induction type polymer membrane is formed of an ion exchangeable polymer, and the liquid flow induction type polymer membrane is formed by continuously arranging the liquid flow induction type polymer membrane in the liquid flow induction type polymer membrane, wherein the slope faces of the prism patterns alternately have different hydrophilicity along the arrangement direction of the prism patterns. A liquid flow induction type polymer membrane is provided.

And the liquid flow guide portion is formed integrally with a rim of the plate.

The liquid flow guide portion includes a plurality of unit liquid flow guide portions spaced apart from each other along a rim of the plate and having a plurality of prism patterns each having an inclined plane intersecting with each other and continuously arranged in one direction.

And the length of the plurality of prism patterns of the unit liquid flow guide portion is reduced from the center of the plate toward the rim direction.

Wherein at least one of the inclined planes constituting both side surfaces of the prism pattern includes a surface formed of the ion-exchangeable polymer (a) and a hydrophilic film (b) on the other surface.

The contact angle of the surface of the (a) ion-exchangeable polymer with respect to the liquid is 80 ° to 90 °, and the contact angle of the hydrophilic film with respect to the liquid is 15 ° to 25 °.

The ion exchangeable polymer (a) may be selected from the group consisting of sulfonated polyether ether ketone (SPEEK), Nafion composite, and sulfonated poly (arylene ether sulfone) , SPAES). ≪ / RTI >

The hydrophilic film (b) is a thin film of at least one metal selected from platinum, chromium, gold and silver.

The hydrophilic film (b) has a thickness of 5 to 20 nm.

And the angle formed between the opposed inclined surfaces of the prism patterns adjacent to each other in the liquid flow induction-type polymer membrane is 20 to 130 degrees.

And a ratio of a period and a height of a cross section intersecting the longitudinal direction of the prism pattern is 1: 0.25 to 1: 4.

And the thickness of the liquid flow guide portion and the plate in the region where the liquid flow inducing portion is formed is 30 to 100 탆.

When the liquid flow-inducing portion is formed on both surfaces of the plate, flows of the liquid respectively guided from both surfaces of the plate are opposite to each other.

The liquid flow-induction-type polymer membrane is a polymer electrolyte membrane for a fuel cell.

According to another representative aspect of the present invention, there is provided a plasma display panel comprising: a cathode and an anode arranged opposite to each other; And an electrolyte membrane disposed between the cathode and the anode, wherein the electrolyte membrane provides the liquid flow induction-type polymer membrane.

According to another exemplary aspect of the present invention, there is provided a method of manufacturing a mold, comprising: (A) fabricating a mold having a plurality of prism patterns formed therein; (B) placing a plate including an ion exchangeable polymer on the mold, heating and pressing the plate, and transferring the liquid flow guide portion in which a plurality of the prism patterns are continuously arranged in one direction on one side or both sides of the plate; (C) a plate including the ion exchangeable polymer to which the liquid flow inducing part including the prism patterns obtained in the step (B) is transferred, wherein the inclined surfaces of the prism patterns alternately have different hydrophilicity along the arrangement direction of the prism patterns Forming a hydrophilic film on one of the slanted surfaces of the prism patterns so that the liquid flow-inducing polymer membrane has a hydrophilic property.

The liquid flow guide portion includes a plurality of unit liquid flow guide portions spaced apart from each other along a rim of the plate and having a plurality of prism patterns each having an inclined plane intersecting with each other and continuously arranged in one direction.

And a ratio of a period and a height of a cross section intersecting the longitudinal direction of the prism pattern is 1: 0.25 to 1: 4.

Wherein the hydrophilic film is at least one metal thin film selected from platinum, chromium, gold and silver.

Since the plurality of prism patterns included in the liquid flow induction type polymer membrane according to the present invention have a physically symmetrical structure and have a chemically asymmetric structure with different degrees of hydrophilicity, It is possible to induce the liquid flow to be unidirectional through the closed channel as well as the open channel.

In addition, when the liquid flow-induction-type polymer membrane is used as a polymer electrolyte membrane for a fuel cell, it is possible to control the water content of the electrolyte membrane, and thus it is difficult to control the moisture content of the electrolyte membrane during operation of the fuel cell, It is possible to solve the problem that the interface between the membrane and the electrode is desorbed and the cell resistance increases.

1 is a schematic view for explaining a contact angle.
2 is a schematic diagram of a prism pattern.
FIG. 3A is a schematic view of a liquid flow induction type polymer membrane according to the present invention, which is a schematic view of a liquid flow induction type polymer membrane in which a liquid flow induction portion including a prism pattern is formed on one side of a plate.
FIG. 3B is a schematic view of a liquid flow induction type polymer membrane according to the present invention, which is a schematic view of a liquid flow induction type polymer membrane having a liquid flow guide portion including a prism pattern on both sides of a plate.
FIG. 4 is a schematic view showing a principle in which a unidirectional flow of liquid is induced in the liquid flow induction type polymer membrane according to the present invention.
5 is a schematic view showing the ratio of the period and the height of the prism pattern formed on the liquid flow induction type polymer membrane according to the present invention.
6 is a schematic view showing the thickness of the liquid flow induction type polymer membrane according to the present invention.
7 is a schematic view of a fuel cell including a liquid flow induction type polymer membrane according to the present invention as an electrolyte membrane.
FIG. 8A is a schematic view showing that a liquid flow inducing unit is formed at a rim of a liquid flow induction type polymer membrane according to the present invention. FIG.
FIG. 8B is a vertical cross-sectional view of a fuel cell including a liquid flow induction type polymer membrane having a liquid flow guide portion formed on a rim portion of one surface according to the present invention. FIG.
8C is a longitudinal sectional view of a fuel cell including a liquid flow induction type polymer membrane having a liquid flow guide portion formed on both sides of a rim according to the present invention.
9A is a perspective view of a liquid flow induction type polymer membrane in which unit liquid flow inducing portions are spaced apart from each other along a rim of one surface of a plate.
FIG. 9B is a perspective view of a liquid flow induction type polymer membrane formed such that the length of the unit liquid flow guide portion becomes shorter toward the outer periphery of the plate.
10 is an optical image of the liquid flow induction type polymer membrane prepared in Example 1, taken by an optical microscope.
11 is a photograph showing the behavior of liquid on the liquid flow induction type polymer membrane prepared in Example 1. Fig.
12 is a graph showing the relationship between a first inclined plane (a slope including a Cr film) and a second inclined plane (a plane formed by Nafion) of an adjacent prism pattern among a plurality of prism patterns included in the liquid flow- (Inclined surface including the inclined surface).
Fig. 13 is a polarization curves graph of measured membrane electrode assemblies prepared in Example 2 and Comparative Example 1, respectively. Fig.

Hereinafter, various aspects and various embodiments of the present invention will be described in more detail.

As used herein, the term " droplet (DP) " refers to a liquid or a portion of a liquid forming a droplet shape.

In this specification, a 'prism pattern' is as shown in FIG.

2 (a) is a schematic view of the prism pattern, wherein the prism pattern has a triangular cross-section in the longitudinal direction LD.

2 (b) is a cross section crossing the longitudinal direction LD of the prism pattern, and the cross section may be an isosceles triangle.

FIG. 2C is a schematic diagram in which a plurality of prism patterns are linearly arranged in a width direction WD, and includes a plurality of prisms and a plurality of prisms. In this case, the space formed between the opposed inclined planes of the neighboring prism patterns is referred to as 'channel CL', and the ridge portion of the prism pattern between the plurality of bones is referred to as 'ridge line (RL)'.

FIG. 3 (d) is a cross-sectional view of the plurality of prism patterns linearly arranged in the width direction WD and crossing the longitudinal direction LD of the plurality of prism patterns, wherein the distance between the mountains and the mountains, Is referred to as a 'period (p)' or 'pitch (p)', and a distance from a base to a vertex of the section is referred to as 'height (h)'.

An angle formed by the opposite inclined planes of the neighboring prism patterns among the plurality of prism patterns is referred to as a 'prism angle?', And an angle between the base line and the hypotenuse is referred to as a 'base angle?'.

One aspect of the present invention relates to a liquid flow induction type polymer membrane 1 as shown in Fig. 3,

The liquid flow induction type polymer membrane (1) comprises a plate (10); And a liquid flow guide part (20) integrally formed on one or both surfaces of the plate (10) and guiding a one - way flow of liquid in a direction of low hydrophilicity, wherein the liquid flow guide part (20) The inclined surfaces 31 and 32 of the prism patterns 30 are aligned along the arrangement direction of the prism patterns 30 so that the prism patterns 30 are arranged in a single direction continuously in a single direction, And the liquid flow-inducing type polymer membrane may be made of ion-exchangeable polymer.

According to an embodiment of the present invention, the liquid flow induction type polymer membrane (1) is a polymer membrane capable of one direction flow of liquid in a direction of low hydrophilicity, wherein the liquid flow induction type polymer membrane Due to the chemically asymmetric structure due to the different symmetrical structure of the prism patterns 30 and the different hydrophilicity of the first inclined plane 31 and the second inclined plane 32 of the opposed prism patterns 30, Directional flow can be induced.

The physical symmetry of the neighboring prism patterns 30 means that the neighboring prism patterns 30 have the same size and shape.

The chemically asymmetric structure of the neighboring prism patterns 30 is due to the different hydrophilicity of the opposing first and second inclined surfaces 31 and 32 of the neighboring prism patterns 30, Can be confirmed by the contact angle of the liquid with respect to the second inclined surface (31) and the second inclined surface (32). That is, the first inclined surface 31 and the second inclined surface 32 have different contact angles, and a flow path can be formed in a direction in which the contact angle with respect to the liquid is small, and the flow of the liquid is a slip-stick behavior And the slip-stick behavior will now be described in more detail with reference to FIG.

4 is a schematic view showing a principle in which a unidirectional flow of liquid is induced in the liquid flow induction type polymer membrane according to the present invention. The schematic view shows a principle in which a unidirectional flow of the liquid is induced by using a cross section crossing the longitudinal direction of the liquid flow induction type polymer membrane.

4A, when a liquid is injected onto a plurality of prism patterns formed on the liquid flow induction-type polymer film 1, the liquid is injected into the plurality of prism patterns 30 And forms droplets (DP) in the form of droplets to cover the formed channels (CN) to the mountains of the plurality of prism patterns (30).

As shown in FIG. 4B, when the liquid is continuously applied onto the plurality of prism patterns, the size of the droplet DP becomes large, and both sides of the droplet DP are spaced apart from each other, And remains in the stopped state while being in contact with the ridgeline RL of the pattern.

Thereafter, when the liquid is further supplied, the size of the droplet DP becomes larger, and the stop state is maintained until the both sides of the droplet DP reach the critical contact angle? _C for the adjacent slopes maintain.

The first inclined surface 31 and the second inclined surface 32 may be formed so that the first inclined surface 31 and the second inclined surface 32 oppose each other with respect to the prism patterns adjacent to each other among the plurality of prism patterns, Accordingly, the critical contact angle? _C expressed by the following equation (1) can also be larger. For example, the first inclined surface 31 may be an inclined surface including a hydrophilic film, and the second inclined surface 32 may be an inclined surface including a surface formed of an ion-exchangeable polymer.

[Equation 1]

θ _c = θ ^* + α

In Equation (1),? ^* Is an equilibrium contact angle on a flat surface, that is, a specific contact angle,

Alpha is an angle formed by a base and a hypotenuse in a triangular cross section intersecting the longitudinal direction of the prism pattern, that is, a base angle.

In other words, when the first inclined plane 31 has a greater hydrophilicity than the second inclined plane 32, the critical contact angles of the liquid with respect to the first and second inclined planes 31 and 32 are denoted by? _{1, c,} and? _{2, and c} , θ _{1, c} > θ _{2, c} , where θ _{1, c} = θ ₁ ^* + α and θ _{2, c} = θ ₂ ^* + α.

Since both side surfaces of the droplet DP are adjacent to the first and second sloping surfaces 31 and 32 and the second and the third _c sides are smaller than the first and the second _c sides _, a contact angle of one side of the contact angle for both sides of the liquid drop (DP) wherein θ _2, and exposed first to _c, and to keep the stop state until the liquid drop (DP) is to be in contact with the θ _{2, c,} wherein θ _{2 , the} liquid begins to move from the first inclined surface 31 toward the second inclined surface 32 when the droplet DP becomes larger than the threshold value _c .

The liquid droplet DP has a contact angle? _{2, c} of the second inclined plane 32 having a relatively small critical contact angle among the first and second inclined planes 31 and 32, as shown in FIG. 4 ( _c ) The liquid moves toward the second inclined surface 32 to observe one directional flow of the liquid from the first inclined surface 31 having a relatively large critical angle of contact to the second inclined surface having a relatively small contact angle. That is, a flow of liquid from a slope having a relatively small hydrophilicity to a large slope is induced.

If the hydrophilic properties of the opposing first and second inclined surfaces of the neighboring prism patterns are the same and the contact angles are the same, the contact angle at which both sides of the droplet contact are the same, so that both sides of the droplet simultaneously A flow of liquid is induced in the direction of the liquid.

Therefore, it can be understood that the one-directional flow of the liquid in the liquid flow-inducing type polymer membrane produced is caused by the difference in chemical characteristics, for example, hydrophilicity, of the opposite inclined planes of the neighboring prism patterns.

According to one embodiment, the liquid flow-induction-type polymer membrane is made of an ion-exchange polymer, and one of the opposing first sloping faces and the second sloping faces of the neighboring prism patterns is formed of the ion exchangeable polymer (a) (B) comprises a hydrophilic membrane, and the other surface comprises (b) a hydrophilic membrane.

According to another embodiment, the contact angle of the surface formed with the ion-exchangeable polymer (a) to the liquid is 80 to 90 degrees, preferably 83 to 87.8 degrees, and the contact angle of the hydrophilic film to the liquid is 15 ° to 25 °, preferably 21.3 ° to 22.7 °.

Therefore, a contact angle with respect to the liquid from the inclined surface including the surface formed of the ion-exchangeable polymer (a), which has a relatively large contact angle with respect to the liquid, among the opposed first inclined plane and the second inclined plane of the neighboring prism patterns, The flow of liquid can be induced to the inclined surface including the small hydrophilic film (b).

According to another embodiment, the ion exchangeable polymer (a) is selected from the group consisting of sulfonated polyether ether ketone (SPEEK), Nafion composite and sulfonated polyarylene ether sulfone Sulfonated poly (arylene ether sulfone), SPAES).

According to another embodiment, the hydrophilic film (b) may be a thin film of at least one metal selected from platinum, chromium, gold and silver.

According to another embodiment, the thickness of the hydrophilic film (b) may be 5 to 20 nm.

The hydrophilic film (b) may be a thin film deposited on one of the first inclined surface and the second inclined surface opposite to each other of the neighboring prism patterns. If the thickness of the hydrophilic film (b) is less than 5 nm, The inclined surface can not be stably modified by hydrophilicity, and if it is more than 20 nm, the thickness of the hydrophilic film is too thick to cause cracks.

According to another embodiment, the angle between the opposed first inclined surface and the second inclined surface of the neighboring prism patterns, that is, the prism angle (gamma) may be 20 ° to 130 °.

If the angle between the first inclined surface and the second inclined surface (prism angle, gamma) is less than 20 °, there may be a problem that the flow of the liquid is lost due to the low step, There may be structurally unstable problems.

5, the ratio of the period (p) and the height (h) of the cross section intersecting the longitudinal direction LD of the prism pattern may be 1: 0.25 to 1: 4 have.

The prism pattern may be structurally unstable when the ratio of the width w and the height h of the cross section intersecting the longitudinal direction of the prism pattern is less than 1: 0.25. If the ratio is less than 1: 4, The flow may lose directionality.

The period p of the cross section intersecting with the longitudinal direction of the prism pattern satisfies the above-mentioned ratio, while the period p and the height h of the cross section crossing the longitudinal direction of the prism pattern satisfy the above- 100 탆, and the height h is preferably 5 to 100 탆.

According to another embodiment, as shown in FIG. 6, the thickness t of the plate 10 in which the liquid flow guide portion 20 is formed may be 30 to 100 μm. That is, the thickness of the plate 10 on which the liquid flow inducing unit 20 is formed means the thickness of the liquid flow induction-type polymer membrane 1.

The thickness of the plate 10 formed with the liquid flow guide portion 20 is the total thickness plus the thickness of the plate 10 and the thickness of the liquid flow guide portion 20, (A) of FIG. 6) or on both sides (FIG. 6 (b)) of the plate 10.

If the thickness of the plate 10 on which the liquid flow inducing unit 20 is formed is less than 10 탆, the mechanical rigidity is weakened, which may be unsuitable for use as an electrolyte membrane of a fuel cell. If the thickness is more than 200 탆, There is a problem that the fuel cell becomes thick when applied, and there may be a problem of performance reduction due to an increase in membrane resistance.

According to another embodiment, the liquid flow induction type polymer membrane may be a polymer electrolyte membrane for a fuel cell.

7, when the liquid flow-induction-type polymer membrane 1 is applied as a polymer electrolyte membrane for a fuel cell, a cathode 41 (an electrode of the fuel cell 40) on both sides of the liquid flow- And the anode 42 may be positioned respectively (Fig. 7 (a) and (b)).

The liquid flow induction type polymer membrane 1 and the liquid flow induction type polymer membrane 1 are formed in consideration of the installation space of a member such as a gasket when the liquid flow induction type polymer membrane 1 and the cathode 41 and the anode 42 are laminated. May be 1.1 to 1.5 times larger than the area of the electrodes such as the cathode 41 and the anode 42 and the center of the cathode 41 and the anode 42 may be larger than the area of the cathode 41 and the anode 42, The cathode 41 and the anode 42 may be positioned at the center of both sides of the liquid flow induction-type polymer membrane 1 (Fig. 7 (c)).

According to another embodiment, as shown in FIG. 8A, the liquid flow guide portion 20 may be integrally formed on the edge portion 11 of one side or both sides of the plate 10. When the liquid flow induction type polymer membrane 1 is applied to the electrolyte membrane of the fuel cell 40, the cathode 41 and the anode 42 are connected to the edge of the liquid flow induction type polymer membrane 1 It may mean the remaining part except the center part located on one side or both sides.

Conventionally, the fuel cell has a problem that it is difficult to control the moisture content of the electrolyte membrane when the fuel cell is driven, the hydration and dehydration processes are repeatedly performed, and the interface between the electrolyte membrane and the electrode is removed.

However, as described above, when the liquid flow induction portion 20 is integrally formed on one or both sides of the plate 10 as an electrolyte membrane of a fuel cell It is possible to appropriately supply water to a desired region in the fuel cell through the design of the structure due to the unidirectional liquid flow in the liquid flow inducing unit 20 so that the moisture of the electrolyte membrane can be controlled.

8B, when the liquid flow guide portion 20 is integrally formed on the rim portion 11 of one side of the plate 10, the direction of the liquid flow appearing in the liquid flow guide portion 20 is the same as that of the plate (X direction) from the center of the substrate 10.

One surface of the electrolyte membrane in contact with the cathode in the fuel cell has a free water, i.e., a high water content, which forms a water channel through which hydrogen ions can freely move.

Therefore, when the liquid flow induction-type polymer membrane 1 formed integrally with the rim 11 on one side of the plate 10 is applied to the electrolyte membrane of the fuel cell 40, The direction of the liquid flow in the liquid flow guide portion 20 is set such that the liquid flow direction in the liquid flow guide portion 20 is in contact with the cathode 41 of the fuel cell 40, (X direction) of the inductive polymer membrane 1, water can be appropriately supplied to a desired region in the fuel cell through designing of the structure, and moisture of the electrolyte membrane of the fuel cell 40 can be controlled.

The liquid flow guide portion 20 formed on both sides of the plate 10 when the liquid flow guide portion 20 is integrally formed on the rim portion 11 on both sides of the plate 10 as shown in FIG. The direction of the liquid flow appearing in the flow direction may be opposite to each other.

One surface of the electrolyte membrane in contact with the cathode in the fuel cell has free water, i.e., a high water content, which forms a water channel through which hydrogen ions can move freely, while the other surface of the electrolyte membrane in contact with the anode is free water (free water) evaporates and can be dried.

Therefore, when the liquid flow induction-type polymer membrane 1 formed integrally with the rims 11 on both sides of the plate 10 is applied to the electrolyte membrane of the fuel cell 40, The flow of the liquid is adjusted in the outward direction (x direction) of the liquid flow induction-type polymer membrane 1 at the interface with the cathode 41 in the liquid flow guide portion 20 contacting the cathode 41 of the battery 40 A flow of liquid flows from the outer periphery of the liquid flow induction-type polymer membrane 1 toward the interface with the anode 42 in the direction of the y direction It is possible to control the excessive moisture content at the portion of the fuel cell 40 that contacts the cathode 41 and to prevent the drying problem that may occur at the portion of the fuel cell 40 contacting the anode 42 .

According to another embodiment, the liquid flow induction-type polymer membrane may include a plurality of unit liquid flow inducing portions spaced apart from each other along a rim of one or both surfaces of the plate.

9A shows a liquid flow induction type polymer membrane 1 including a plurality of unit liquid flow induction parts 21 formed such that the liquid flow inducing parts 20 are spaced apart from each other along a rim 11 of one side of the plate 10. [ FIG.

When the liquid flow-inducing polymer membrane 1 of FIG. 9A is used as an electrolyte membrane of a fuel cell, the cathode of the fuel cell may be laminated on one surface of the liquid flow inducing unit 20.

The plurality of unit liquid flow guide portions 21 may be spaced apart from each other in the longitudinal direction and in a direction parallel to the sides of the plate 10, and the shape of the cross section of the plurality of unit liquid flow guide portions 21 may be It can be a square.

The plurality of unit liquid flow guide portions 21 are spaced apart from each other. In particular, the unit liquid flow guide portions 21 are not formed at the corners of the plate 10, It is possible to prevent the mechanical strength from being weakened by laminating the liquid flow induction type polymer membrane 1, the cathode and the anode, which are used as the electrolyte membrane, and then sealing them by applying pressure.

9B, the liquid flow-induction-type polymer membrane 1 may include a plurality of unit liquid flow inducing portions (not shown) formed on one or both sides of a rim 11 of the plate 10 The length L of the longitudinal direction LD of the unit liquid flow guide portion 21 can be shortened from the inner circumferential surface of the rim portion 11 toward the outer circumferential surface in the x direction. The length L of the longitudinal direction LD of the unit liquid flow guide portion 21 means the length of the longitudinal direction LD of the prism pattern included in the unit liquid flow guide portion 21.

9B is a cross-sectional view of a liquid flow induction type polymer membrane (hereinafter, referred to as " liquid flow induction type polymer membrane ") formed such that the length (L) of the plurality of unit liquid flow inducing portions 21 included in the liquid flow inducing portion 20 becomes shorter toward the outer peripheral surface of the rim portion 11. 1).

When used as an electrolyte membrane of the fuel cell of the liquid flow induction-type polymer membrane 1 of FIG. 9B, the cathode of the fuel cell may be laminated on one surface of the liquid flow inducing unit 20.

The longitudinal direction LD of the unit liquid flow inducing portion 21 formed in the rim portion 11 of the liquid flow induction-type polymer membrane 1 may be arranged in a direction in which the sides of the plate 10 are parallel to each other. The unit liquid flow inducing portion 21 contacts each side of the cathode 41 when the cathode 41 is stacked and the unit liquid flow inducing portion 21 is connected to each side of the cathode 41, The length l of the longitudinal direction LD can be made shorter from the inner peripheral surface of the portion 11 to the outer peripheral surface (x direction).

For example, the shape of the transverse section of the unit liquid flow inducing portion 21 may be such that the bottom surface of the edge portion of the edge portion 11, which is in contact with the cathode 41, It can be a triangle. In this case, it may be more advantageous to control the excessive moisture content generated at the portion where the unit liquid flow inducing portion 21 and the cathode 41 are in contact with each other.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: (A) fabricating a mold having a plurality of prism patterns formed therein; (B) placing a plate including an ion exchangeable polymer on the mold, heating and pressing the plate, and transferring the liquid flow guide portion in which a plurality of the prism patterns are continuously arranged in one direction on one side or both sides of the plate; (C) a plate including the ion exchangeable polymer to which the liquid flow inducing part including the prism patterns obtained in the step (B) is transferred, wherein the inclined surfaces of the prism patterns alternately have different hydrophilicity along the arrangement direction of the prism patterns And forming a hydrophilic film on one of the slanted faces of the prism patterns so that the liquid flow induction-type polymer film has a hydrophilic property.

The mold may be made of a polymer, for example, the polymer may be polydimethylsiloxane (PDMS).

According to one embodiment, the plurality of prism patterns may be formed along the rim of the mold.

According to another embodiment, the ratio of the width and the height of the cross section crossing the longitudinal direction of the prism pattern may be 1: 1 to 2: 1.

According to another aspect of the present invention, there is provided a plasma display panel comprising: a cathode and an anode arranged opposite to each other; And an electrolyte membrane disposed between the cathode and the anode, wherein the electrolyte membrane is the liquid flow induction type polymer membrane.

Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the scope and content of the present invention can not be construed to be limited or limited by the following Examples. In addition, it is apparent that, based on the teachings of the present invention including the following examples, those skilled in the art can easily carry out the present invention in which experimental results are not specifically shown.

Production Example 1: Production of PDMS mold

A master mold for manufacturing a mold was prepared by machining. First, a plate made of nickel electroplated stainless steel was prepared, and then the surface of the plate was machined to a specific angle using a diamond cutting tool to form a prism pattern. At this time, the period (pitch) and the angle of the formed prism pattern correspond to the period (pitch) and the angle of the diamond cutting tool, and the height of the prism pattern can be determined by the cutting depth

Thus, a master mold having a prism pattern patterned so as to have a period of 50 μm, a height of 25 μm and a prism angle of 90 ° was manufactured.

After the master mold was prepared, a mixture of the Sylgard 184 polydimethylsiloxane (PDMS) elastomer base and the curing agent (10: 1 w / w) was poured into the master mold patterned with the prism pattern and cured at 70 ° C for 2 hours.

The cured PDMS mold was separated from the master mold and cut.

Example 1: Preparation of liquid flow-inducing type polymer membrane

The Nafion polymer film was placed on the PDMS mold having the prism pattern formed in Production Example 1, and the prism pattern was transferred to one side of the polymer film by heating and pressing. During heating and compression, the polymer film was heat-pressed for 60 minutes under a pressure of 20 kg / cm ² at a temperature of 120 ° C, which is lower than the glass transition temperature (Tg) of 140 ° C of Nafion, to produce a polymer film having a prism pattern on one side .

A 20 nm thick Cr film as a hydrophilic film was coated on the slanted surface of two opposing slopes of the prism patterns transferred from the prism patterns transferred onto the polymer film by oblique deposition.

In this case, when the polymer film including prism patterns is placed on a holder having an inclination angle of 60 °, a slant holder is used. Therefore, when the prism patterns are opposed to each other, A metal layer is deposited only on one of the two slopes.

The polymer membrane having the prism patterns formed thereon is referred to as a liquid flow induction type polymer membrane, and the area of the liquid flow induction type polymer membrane is 3 x 3 cm ² , which is used as an electrolyte membrane. First, the wetting property of the film was measured and used to observe the flow of the liquid by cutting into strips having a width of 1.5 mm or less for analysis.

Experimental Example 1: Physical measurement

The surface of the liquid flow-induction type polymer membrane prepared in Example 1 was photographed with an optical microscope (Olympus IX70, Japan), and the flow of the liquid on the liquid flow-induction type polymer membrane was measured using a contact angle analyzer (KRUSS DSA 100, Germany) I took a video.

10 is an optical image of the liquid flow induction type polymer membrane prepared in Example 1, taken by an optical microscope.

Referring to FIG. 10, it was confirmed that the period of the prism pattern formed on the liquid flow induction type polymer membrane was 50 μm, the height was 25 μm, and the prism angle was 90 °. Further, it can be seen from the optical image that the plurality of prism patterns formed on the liquid flow-induction-type polymer membrane have structural symmetry. Also, it can be seen that the prism patterns have chemical asymmetry due to the Cr film, which is a metal film selectively deposited on one of two opposite slopes of the prism patterns of the plurality of prism patterns.

11 is a photograph showing the behavior of liquid on the liquid flow induction type polymer membrane prepared in Example 1. Fig.

11, when a liquid such as a water droplet is placed on the liquid flow induction-type polymer membrane and the volume of the liquid is increased at a constant rate of 1 μL / min, the flow of the liquid is controlled by the stepwise movement of a typical stick- Respectively. The wettability can be explained by the Wenzel state since the droplet wetts the entire prism pattern structure.

Furthermore, it can be seen that as the volume of the water droplet increases, the front surface of the liquid that has moved forward can not advance further from the ridgeline (RL). When the droplet overcomes the energy barrier, the front of the droplet quickly rises past the ridge (RL) to the next valley and then stops again. Such a stop-and-over cycle repeats and flows along the ridge of the channel formed by the prism pattern structure .

From this point of view, this unidirectional flow will be referred to as "step flow ".

The front surface of the water droplet moves in one direction toward the metal film. In addition, the same step flow was observed in the prism pattern structure having a pattern period of 25 μm, indicating that a directional flow can be realized even at a smaller scale.

12 is a graph showing the relationship between a first inclined plane (a slope including a Cr film) and a second inclined plane (a plane formed by Nafion) of an adjacent prism pattern among a plurality of prism patterns included in the liquid flow- (Inclined surface including the inclined surface).

As shown in Fig. 12, the contact angle of the first inclined surface (inclined surface including Cr film) is 85.5 deg., And the contact angle of the second inclined surface (inclined surface including the surface formed by Nepion) is 22.0 deg.

Example 2: Preparation of membrane electrode assembly (MEA)

In Example 1, a membrane electrode assembly (MEA) was prepared using a liquid flow-inducing type polymer membrane. As the anode and cathode catalyst, a commercial catalyst (TANAKA) containing 46.6 wt% of platinum in a carbon carrier was used, and a catalyst slurry was prepared by using isopropyl alcohol and 5 wt% NaOH solution.

After the prepared catalyst slurry was mixed by ultrasonication, the platinum content of the anode was 0.2 mg · cm ^-2 and the platinum content of the cathode was 0.4 mg · cm ^-2 in the liquid flow-inducing type polymer membrane in Example 1 After that, a membrane electrode assembly was prepared using a spray gun (Pattern MEA).

The electrode area of the membrane electrode assembly was 5 cm ^2, and the gas diffusion layer was attached to both electrodes of the membrane electrode assembly with a 10BC product of SGL.

Comparative Example 1: Membrane Electrode Assembly (MEA) Control Group

A membrane electrode assembly was prepared using a commercial polymer membrane (NRE-212, Dupont Co.) (Reference MEA), and the performance was compared using the same catalyst, gas diffusion layer, and unit cell as in Example 2.

Experimental Example 2: Evaluation of fuel cell performance

A fuel cell performance evaluation was performed on the membrane electrode assembly (Pattern MEA) using the liquid flow induction type polymer membrane prepared in Example 2 and the membrane electrode assembly (Reference MEA) using the commercial polymer membrane prepared in Comparative Example 1 . For the performance evaluation, the unit cell temperature was set at 80 ℃ and hydrogen and oxygen with relative humidity of 100% were applied to the unit cell at stoichiometric ratios of 1.5 and 2.0.

Fig. 13 is a polarization curves graph of measured membrane electrode assemblies prepared in Example 2 and Comparative Example 1, respectively. Fig.

13, a membrane electrode assembly (Pattern MEA) using the liquid flow-induction type polymer membrane of Example 2 at a current density of 1.0 Acm ^-2 or higher was used as the membrane electrode using the commercial polymer membrane of Comparative Example 1 The voltage was higher than that of the reference MEA.

The current density of the membrane electrode assembly (Reference MEA) using the commercial polymer membrane of Comparative Example 1 at a voltage of 0.4 V was 1.839 Acm ^-2, and the membrane electrode assembly (Pattern MEA) using the liquid flow- The current density was 2.798 Acm ^{-2, which} was 0.959 Acm ^-2 .

Also, in the case of the membrane electrode assembly (Reference MEA) using the commercial polymer membrane of Comparative Example 1, a sharp voltage drop was observed at a current density of 1.60 Acm ^-2 or more and the measurement was stopped at a current density of 1.9 Acm ^-2 appear. On the other hand, in the case of the membrane electrode assembly (Pattern MEA) using the liquid flow-induction type polymer membrane of Example 2, the current density was stably measured up to 3.00 Acm ^-2 .

From this, it can be seen that the membrane electrode assembly (Pattern MEA) using the liquid flow-induction type polymer membrane according to the second embodiment has a problem that due to the hydrophilicity difference, the one- It was found that the membrane electrode assembly could be operated stably at a high current.

As described above, when the liquid flow induction type polymer membrane according to the present invention is applied as an electrolyte membrane of a fuel cell by allowing a one-way flow of liquid, moisture of the electrolyte membrane can be controlled and the battery can be stably driven at a high current It is possible to confirm the application of the fuel cell of the next generation which requires long-term life safety as an electrolyte membrane.

It will be apparent to those skilled in the art that the present invention is not limited to the embodiments described above and that various changes and modifications may be made without departing from the spirit and scope of the present invention as defined by the appended claims. As shown in FIG.

It will be understood by those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention as defined by the appended claims and their equivalents. .

10: Plate
11:
20: liquid flow guide portion, 21: unit liquid flow guide portion
30: prism pattern
31: first inclined surface, 32: second inclined surface
33: surface formed of ion-exchangeable polymer, 34: hydrophilic membrane
40: Fuel cell
41: cathode 42: anode
ℓ: Length of unit liquid flow guide
LD: length (of the prism pattern)

Claims (19)

plate; And
And a liquid flow guide part integrally formed on one surface or both surfaces of the plate and guiding a one-way flow of the liquid in a direction of low hydrophilicity,
Wherein the liquid flow inducing unit is a liquid flow induction type polymer membrane in which a plurality of prism patterns each having an inclined plane intersecting is continuously arranged in one direction,
The inclined surfaces of the prism patterns alternately have different hydrophilicity along the arrangement direction of the prism patterns,
Wherein the liquid flow-induction-type polymer membrane is made of an ion-exchange polymer. The method according to claim 1,
The liquid flow-
Wherein the liquid flow induction-type polymer membrane is integrally formed at an edge of the plate. The method according to claim 1,
The liquid flow-
And a plurality of unit liquid flow inducing portions spaced from each other along the rim portion (30) of the plate and having a plurality of prism patterns each having an inclined plane intersecting each other and continuously arranged in one direction. . The method of claim 3,
Wherein a length of the plurality of prism patterns of the unit liquid flow induction portion is reduced in a direction from a center of the plate toward an edge of the plate. The method according to claim 1,
Wherein at least one of the inclined surfaces constituting both side surfaces of the prism pattern comprises a surface formed of the ion-exchangeable polymer and the hydrophilic film. 6. The method of claim 5,
Wherein the contact angle of the surface formed with the ion-exchangeable polymer (a) to the liquid is 80 ° to 90 °, and the contact angle of the hydrophilic film with respect to the liquid is 15 ° to 25 °. . 6. The method of claim 5,
The ion exchangeable polymer (a) may be selected from the group consisting of sulfonated polyether ether ketone (SPEEK), Nafion composite, and sulfonated poly (arylene ether sulfone) , SPAES). ≪ / RTI > 6. The method of claim 5,
Wherein the hydrophilic membrane (b) is at least one metal thin film selected from platinum, chromium, gold and silver. 6. The method of claim 5,
Wherein the hydrophilic film (b) has a thickness of 5 to 20 nm. The method according to claim 1,
Wherein the angle formed by the opposite inclined surfaces of the adjacent prism patterns is 20 to 130 deg.. The method according to claim 1,
Wherein the ratio of the periodicity and the height of the cross section of the prism pattern in the longitudinal direction is 1: 0.25 to 1: 4. The method according to claim 1,
Wherein the thickness of the liquid flow-inducing portion and the plate in the region where the liquid flow inducing portion is formed is 30 to 100 占 퐉. The method according to claim 1,
Wherein when the liquid flow inducing portion is formed on both surfaces of the plate, flows of the liquids guided from both sides of the plate are opposite to each other. The method according to claim 1,
Wherein the liquid flow induction type polymer membrane is a polymer electrolyte membrane for a fuel cell. A cathode and an anode arranged opposite to each other; And
And an electrolyte membrane disposed between the cathode and the anode,
The fuel cell according to any one of claims 1 to 14, wherein the electrolyte membrane is a liquid flow induction type polymer membrane. (A) fabricating a mold having a plurality of prism patterns formed therein;
(B) placing a plate including an ion exchangeable polymer on the mold, heating and pressing the plate, and transferring the liquid flow guide portion in which a plurality of the prism patterns are continuously arranged in one direction on one side or both sides of the plate;
(C) a plate including the ion exchangeable polymer to which the liquid flow inducing part including the prism patterns obtained in the step (B) is transferred, wherein the inclined surfaces of the prism patterns alternately have different hydrophilicity along the arrangement direction of the prism patterns And forming a hydrophilic film on one of the slanted surfaces of the prism patterns so that the hydrophilic film has a hydrophilic property. 17. The method of claim 16,
The liquid flow-
And a plurality of unit liquid flow inducing portions spaced apart from each other along the rim of the plate and having a plurality of prism patterns each having an inclined plane intersecting each other and continuously arranged in one direction. 17. The method of claim 16,
Wherein the ratio of the periodicity and the height of the cross section of the prism pattern in the longitudinal direction is 1: 0.25 to 1: 4. 17. The method of claim 16,
Wherein the hydrophilic film is at least one metal thin film selected from platinum, chromium, gold and silver.

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