JP2009229136A - Dynamic contact angle measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dynamic contact angle measuring device for measuring a dynamic contact angle excellently, even when a liquid sample is moved at high speed of about several meters/second or higher relative to a solid sample. <P>SOLUTION: A measuring container 10 includes a channel 10a in which the liquid sample flows. A part of the measuring container 10 includes a transparent body, and a part of the inner surface of the measuring container 10 partitioning the channel 10a includes the solid sample. A liquid supply recovery means 20 supplied and/or recovers the liquid sample to/from the channel 10a at an optional flow rate. A photographing means 30 photographs a liquid surface shape of the liquid sample flowing in the channel 10a from a part of the transparent body of the measuring container 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a dynamic contact angle measuring apparatus, and more particularly to a dynamic contact angle measuring apparatus for measuring a dynamic contact angle at an interface between a solid sample and a liquid sample moving on the surface of the solid sample.

  The fluidity when the liquid flows in the flow path is affected by the wettability at the interface between the solid and the liquid that defines the flow path. That is, if the wettability at the interface between the solid and the liquid defining the flow path is good, the fluidity of the liquid flowing in the flow path is high, and if the wettability is bad, the flowability is low. A contact angle is an index for objectively evaluating the degree of wettability at the interface between a solid and a liquid. The contact angle is an angle formed by the liquid surface and the solid surface where the surface of the stationary liquid contacts the solid (an angle inside the liquid). In addition, when the liquid moves on the surface of the solid, the contact angle in the moving state is called a dynamic contact angle.

  Therefore, by measuring the dynamic contact angle between the solid surface that defines the flow path and the liquid level of the liquid in a flowing state, the fluidity when the liquid flows in the flow path is evaluated. be able to.

  Conventionally known methods for measuring the dynamic contact angle include a liquid suitability method, an expansion / contraction method, and a sliding method. In the liquid suitability method, the contact angle of a droplet that spreads instantaneously is continuously measured. In the expansion / contraction method, by measuring the dynamic advancing contact angle in the forced wetting and spreading (expansion) of the liquid by inflating the droplet in contact with the solid surface, or inhaling the droplet in contact with the solid surface Thus, the dynamic reverse contact angle in the forced pulling (shrinking) of the liquid is measured. In the sliding-down method, the liquid sample is slid by tilting the solid sample on which the liquid droplet is placed, and the dynamic advancing contact angle and the dynamic backward contact angle are measured.

In addition, the liquid sample is sandwiched and held between a pair of parallel plates made of a solid sample, and the liquid sample is moved between the two plates by changing the supply amount of the liquid sample between the two plates. A method of measuring the dynamic contact angle by photographing the interface between a liquid sample and a flat plate with a video camera is also known (see, for example, Patent Document 1).
JP 2001-116675 A

  By the way, in the fuel cell, gas and water flow in a flow path formed between the gas diffusion layer and the separator. For this reason, when evaluating the drainage property when water mixed with gas flows in the flow path or determining the width of the flow path, a simulation is performed to determine whether the water mixed with the gas and the gas diffusion layer or separator. The dynamic contact angle at the interface may be measured. Here, the moving speed of the gas-mixed water flowing in the flow path in the fuel cell is about several m / second.

  However, the upper limit of the interface speed at which the dynamic contact angle can be satisfactorily measured by the conventional liquid application method, expansion / contraction method, and sliding method described above is about several mm / second.

  In the method described in Patent Document 1, since the liquid sample sandwiched between a pair of flat plates is moved, it is difficult to move the liquid sample at high speed while stably holding the liquid sample between both flat plates. is there.

  Therefore, depending on these conventional methods, it is difficult to satisfactorily measure the dynamic contact angle at the interface between the gas-mixed water flowing in the flow path in the fuel cell and the gas diffusion layer or separator by simulation.

  The present invention has been made in view of the above circumstances, and even when the liquid sample moves at a high speed of about several m / second or more with respect to the solid sample, the dynamic contact angle can be measured well. An object is to provide a dynamic contact angle measuring device.

  (1) A dynamic contact angle measuring apparatus of the present invention that solves the above-mentioned problems is a dynamic contact angle measuring apparatus that measures a dynamic contact angle at an interface between a solid sample and a liquid sample moving on the surface of the solid sample. A measuring container having a flow path through which the liquid sample flows, liquid supply / recovery means for supplying and / or recovering the liquid sample to the flow path at an arbitrary flow rate, and the liquid sample flowing in the flow path. An imaging means for imaging the liquid surface shape, a part of the measurement container is made of a transparent body, and a part of the inner surface of the measurement container defining the flow path is made of the solid sample, and the flow path The interface between the liquid sample and the solid sample on the liquid surface of the liquid sample flowing inside is configured to be photographed by the photographing means from the outside through the transparent body.

  In the dynamic contact angle measuring apparatus of the present invention, the liquid sample is fed and / or collected at an arbitrary flow rate to the flow path of the measurement container by the liquid supply / recovery means, so that the liquid sample is advanced and / or recovered in the flow path. Or it can be retracted. Therefore, by adjusting the supply and / or recovery amount of the liquid sample from the liquid supply / recovery means to the flow channel of the measurement container, the moving speed of the liquid sample flowing in the flow channel can be easily and reliably changed. it can. Therefore, the liquid sample can be easily and reliably moved at high speed in the flow channel of the measurement container. Then, the interface between the liquid sample and the solid sample on the liquid surface of the liquid sample moving at high speed in the flow path in this way is photographed by the photographing means through the transparent body from the outside, so that the dynamic contact is made from the interface shape. The angle can be measured.

  Therefore, the dynamic contact angle measurement apparatus of the present invention stably measures the dynamic contact angle at the interface between the liquid sample and the solid sample even when the liquid sample moves at high speed in the flow path of the measurement container. It becomes possible.

  (2) Preferably, in the dynamic contact angle measurement device of the present invention, at least one of the measurement containers is made of the solid sample and the inner surfaces face each other in parallel, and at least one of the pair of first facing walls. A pair of second opposing wall portions made of the transparent body. In this case, the flow path is a slit-shaped flow path having a substantially rectangular cross section defined by both the first opposed wall part and the second second opposed wall part. The distance D between the two opposing wall portions is preferably larger than the distance d between the first opposing wall portions.

  Thus, the flow path of the measurement container is a slit-shaped flow path having a substantially rectangular cross section, and the distance D between the two opposing wall portions in the slit-shaped flow path is greater than the distance d between the first opposing wall portions. According to the large configuration, when measuring the dynamic contact angle at the interface between the solid sample and the liquid sample constituting the first opposing wall portion, for example, the center portion in the width direction of the solid sample (that is, both the second opposing wall portions) By measuring the dynamic contact angle at a position farthest from the center, measurement with less error due to the influence of both the second opposing wall portions can be performed.

  (3) Preferably, in the dynamic contact angle measuring device of the present invention, both of the first opposing wall portions are made of the solid sample, and one of the solid samples is made of a material constituting a gas diffusion layer for a fuel cell. The other solid sample is made of a material constituting the fuel cell separator.

  According to this configuration, for example, when water is used as the liquid sample, the dynamics at the interface between each of the gas diffusion layer and the separator that partitions the flow path of water and gas in the fuel cell and the water as the liquid sample are obtained by simulation. The contact angle can be measured.

  (4) In the dynamic contact angle measurement device of the present invention, preferably, the measurement container is rotatable, and the measurement container is held in a state where the flow path extends in an arbitrary angle direction with respect to the vertical direction. The

  According to this configuration, it is possible to measure the dynamic contact angle at the interface between the liquid sample and the solid sample flowing in the flow path extending in an arbitrary angle direction with respect to the vertical direction. For this reason, it becomes possible to measure the dynamic contact angle by arbitrarily changing the direction of gravity acting on the liquid sample flowing in the flow path.

  (5) In the dynamic contact angle measuring apparatus of the present invention, preferably, the liquid supply / recovery means has gas mixing means for mixing gas at an arbitrary ratio into the liquid sample flowing in the flow path.

  According to this configuration, a liquid sample mixed with gas at an arbitrary ratio can be flowed into the flow path, and therefore, the dynamic contact angle at the interface between the liquid sample mixed with gas and the solid sample can be measured.

  Thus, according to the dynamic contact angle measuring apparatus of the present invention, the dynamic contact angle at the interface between the liquid sample and the solid sample moving at high speed in the flow channel of the measurement container can be stably measured. For this reason, the dynamic contact angle measuring device of the present invention can be suitably used, for example, when evaluating the drainage performance of the flow path in the fuel cell.

  Hereinafter, embodiments of the dynamic contact angle measuring device of the present invention will be described in detail. In addition, embodiment described is only one Embodiment and the dynamic contact angle measuring apparatus of this invention is not limited to the following embodiment. The dynamic contact angle measuring device of the present invention can be implemented in various forms that have been modified or improved by those skilled in the art without departing from the scope of the present invention.

  As shown in FIGS. 1 to 3, the dynamic contact angle measuring device of the present embodiment includes a measurement container 10, a liquid supply / recovery means 20, an imaging means 30, and a holding means 40 that holds the measurement container 10. It has.

  FIG. 1 is a partial cross-sectional configuration diagram schematically showing a schematic configuration of the dynamic contact angle measuring apparatus of the present embodiment. FIG. 2 is a perspective view of a measuring container in this dynamic contact angle measuring apparatus. FIG. 3 is a cross-sectional view of the measurement container.

  The measurement container 10 has a flow path 10a inside. The shape of the measuring container 10 is not particularly limited as long as it has a flow path 10a inside. Further, the cross-sectional shape of the channel 10a is not particularly limited. However, the measurement container 10 is made of a transparent body, and a part of the inner surface of the measurement container 10 that partitions the flow path 10a is made of a solid sample.

  The measurement container 10 in the dynamic contact angle measuring apparatus of this embodiment includes a pair of first opposing wall portions 11 and 12 whose inner surfaces face each other in parallel and a pair of second opposing wall portions 13 whose inner surfaces face each other in parallel. , 14.

  The 1st opposing wall parts 11 and 12 are exhibiting the same flat plate shape. Moreover, the 2nd opposing wall parts 13 and 14 are exhibiting the same cross-sectional T shape. The first opposing wall portions 11 and 12 and the second opposing wall portions 13 and 14 are fixed by, for example, an adhesive, whereby the measuring container 10 having a rectangular parallelepiped outer shape is obtained.

  And the flow path 10a formed in this measurement container 10 is a slit-shaped flow path having a substantially rectangular cross section defined by the first opposing wall portions 11 and 12 and the second opposing wall portions 13 and 14. Has been.

  Further, in the flow path 10a as the slit-shaped flow path, the distance D between the second opposing wall portions 13 and 14 is set larger than the distance d between the first opposing wall portions 11 and 12. Here, the distance D between the second opposing wall portions 13 and 14 is preferably at least 5 times the distance d between the first opposing wall portions 11 and 12, and more preferably at least 10 times. , 20 times or more is particularly preferable. In the present embodiment, the distance D between the second opposing wall portions 13 and 14 is 10 mm, the distance d between the first opposing wall portions 11 and 12 is 0.5 mm, and D / d = 20. .

  At least one of the pair of first opposing wall portions 11 and 12 is made of a solid sample. That is, both of the first opposing wall portions 11 and 12 may be constituted by a solid sample, or only one of them may be constituted by a solid sample.

  The material of the solid sample is not particularly limited. Moreover, when both the 1st opposing wall parts 11 and 12 are comprised with a solid sample, both may be made into the same kind of material, and it is good also as a different kind of material. This solid sample can preferably be a material constituting a fuel cell gas diffusion layer or a material constituting a fuel cell separator. That is, when both the first opposing wall portions 11 and 12 are made of a solid sample, one solid sample is made of a material constituting the fuel cell gas diffusion layer, and the other solid sample is a fuel cell separator. It is preferable to consist of the material which comprises. When only one of the first opposing wall portions 11 and 12 is formed of a solid sample, the solid sample is made of a material constituting a fuel cell gas diffusion layer or a material constituting a fuel cell separator. Is preferred.

  Examples of the material constituting the fuel cell gas diffusion layer include a carbon material. Moreover, as a material which comprises the separator for fuel cells, SUS (stainless steel) can be mentioned, for example.

  When only one of the first opposing wall portions 11 and 12 is made of a solid sample, the material of the other first opposing wall portion may be selected as appropriate.

  At least one of the pair of second opposing wall portions 13 and 14 is made of a transparent body. That is, both the second opposing wall portions 13 and 14 may be configured by a transparent body, or only one of them may be configured by a transparent body.

  The material of the transparent body is not particularly limited. Moreover, when both the 2nd opposing wall parts 13 and 14 are comprised with a transparent body, both may be made into the same kind of material and it is good also as a different kind of material. As a material of the transparent body, a transparent organic or inorganic glass can be used, and for example, a transparent acrylic resin can be used.

  Here, in this embodiment, both the 1st opposing wall parts 11 and 12 consist of solid samples, and both the 2nd opposing wall parts 13 and 14 consist of transparent bodies. And the 1st solid sample which comprises the 1st opposing wall part 11 consists of a carbon material as a material which comprises the gas diffusion layer for fuel cells, and the 2nd solid sample which comprises the 2nd opposing wall part 12 is a fuel. It consists of SUS as a material which comprises a battery separator. Moreover, the transparent body which comprises both the 2nd opposing wall parts 13 and 14 consists of a transparent acrylic resin.

  The liquid supply / recovery means 20 is not particularly limited as long as it supplies and / or recovers a liquid sample to the flow path 10a of the measurement container 10 at an arbitrary flow rate. The liquid supply / recovery means 20 may supply and recover the liquid sample at an arbitrary flow rate in the flow path 10a, or may supply or recover only one of the liquid samples. .

  The liquid supply / recovery means 20 in the dynamic contact angle measuring apparatus of the present embodiment includes a pipe line 21 having one end connected to the lower end of the flow path 10a of the measurement container 10 and a cylinder connected to the other end of the pipe line 21. A part 22, a piston part 23 for supplying / recovering the liquid sample stored in the cylinder part 22 by reciprocatingly sliding in the cylinder part 22, and a liquid sample flowing in the channel 10 a Gas mixing means 24 for mixing gas at a ratio of

  That is, in the dynamic contact angle measuring device of this embodiment, the liquid sample in the cylinder part 22 is supplied to the flow path 10a of the measurement container 10 at an arbitrary flow rate by the forward movement of the piston part 23, and the piston part. Recovered by 23 backward movement.

  The piston 23 may be driven manually or electrically. Moreover, when driving the piston part 23 electrically, you may control the action | operation of an actuator by a computer, for example.

  A pump may be employed instead of the piston portion 23 in the liquid supply / recovery means 20.

  The gas mixing means 24 is not particularly limited as long as it can mix a gas into a liquid sample, and for example, a syringe or a pump can be employed. Moreover, the kind of gas mixed in the liquid sample is not particularly limited, and can be, for example, air, oxygen, or hydrogen.

  In addition, the gas mixing means 24 can be provided as needed. That is, the gas supply means 24 may be provided in the liquid supply / recovery means 20 when it is desired to measure the dynamic contact angle of a liquid sample mixed with gas.

  The photographing means 30 is not particularly limited as long as it can photograph the liquid surface shape of the liquid sample moving in the flow path 10a of the measurement container 10, and for example, a high-speed camera (video camera or the like) can be employed. . The imaging means 30 externally connects the interface between the liquid sample and the solid sample on the liquid surface of the liquid sample moving in the flow path 10a of the measurement container 10 via the second opposing wall portion 13 or 14 made of a transparent body. Take a picture.

  The holding means 40 is not particularly limited as long as it can hold the measurement container 10 at a predetermined angle. In addition, if the measurement container 10 itself maintains a predetermined posture, it is not necessary to provide the holding means 40 separately.

  The holding means 40 in the dynamic contact angle measuring device of this embodiment holds the measurement container 10 rotatably. That is, the holding means 40 includes a base 41 and a holding portion 42 that is held at an arbitrary rotation angle with respect to the base 41. By holding the measurement container 10 in the holding portion 42, the measurement container 10 can be held in a state where the flow path 10a extends in a direction at an arbitrary angle with respect to the vertical direction.

  Although not shown, in the dynamic contact angle measurement apparatus of the present embodiment, an irradiation unit that irradiates the inside of the flow channel 10a of the measurement container 10 through the second opposing wall portion 13 or 14 made of a transparent body. It can be provided as necessary.

  Hereinafter, a method for measuring a dynamic contact angle by the dynamic contact angle measuring apparatus of the present embodiment will be described with reference to FIGS.

  First, for example, the measurement container 10 is held by the holding means 40 so that the flow path 10a extends in the vertical direction. Then, the liquid supply / recovery means 20 supplies the liquid sample to the flow path 10a of the measurement container 10 at a target flow rate, and aims at the liquid surface of the liquid sample in the flow path 10a in an area where the imaging means 30 can take an image. Move forward (rise) at a flow rate of At this time, the liquid level of the liquid sample moving forward in the flow path 10 a is imaged by the imaging means 30. Next, a liquid sample is filled in an area that can be imaged by the imaging unit 30, the liquid sample is collected from the flow channel 10 a of the measurement container 10 by the liquid supply / recovery unit 20, and the imaging unit 30 performs imaging. In a possible region, the liquid level of the liquid sample in the flow channel 10a is retracted (lowered) at a target flow rate. At this time, the imaging means 30 images the liquid level of the liquid sample that retreats in the flow path 10a. These forward and backward operations of the liquid sample are repeated while changing the flow rate of supply and recovery.

  Then, the image photographed by the photographing means 30 is displayed in black and white by binarizing, for example, based on the brightness. An image taken when the liquid sample is advanced in the flow path 10a is binarized and displayed in black and white as shown in FIG. 4A. The image is taken when the liquid sample is moved backward in the flow path 10a. FIG. 4 (b) shows a binarized and black and white display.

  In FIG. 4A, the pair of black rectangular portions 51 and 52 on both sides are solid samples constituting the first opposing wall portions 11 and 12, respectively. The upper end surface 53a of the black intermediate portion 53 at the center in the vertical direction between the black rectangular portions 51 and 52 on both sides is the liquid surface of the liquid sample that moves forward (rises). The white rectangular portion 54 above the black intermediate portion 53 between the black rectangular portions 51 and 52 on both sides is air in the flow path 10a. A white substantially rectangular portion 55 below the black intermediate portion 53 between the black rectangular portions 51 and 52 on both sides is a liquid sample. The black intermediate portion 53 is a portion where a liquid sample and air are mixed.

  Similarly, in FIG. 4B, the pair of black rectangular portions 61 and 62 on both sides are solid samples constituting the first opposing wall portions 11 and 12, respectively. The lower end surface 63a of the black intermediate portion 63 at the center in the vertical direction between the black rectangular portions 61 and 62 on both sides is the liquid surface of the liquid sample that retreats (lowers). The white portion 54 above the black intermediate portion 63 between the black rectangular portions 61 and 62 on both sides is air in the flow path 10a. A white substantially rectangular portion 65 below the black intermediate portion 63 between the black rectangular portions 61 and 62 on both sides is a liquid sample. The black intermediate portion 63 is a portion where a liquid sample and air are mixed.

  In FIG. 4A, the tangent line of the liquid sample is drawn at the interface between the liquid sample and one black rectangular portion 61 as the solid sample, and the tangent line and one black as the solid sample are drawn with a protractor. The angle with the rectangular portion 61 is measured with a protractor to measure the forward dynamic contact angle θa of the liquid sample that moves forward (see FIG. 5A).

  Similarly, in FIG. 4B, at the interface between the liquid sample and one black rectangular portion 61 as the solid sample, a tangent line of the liquid surface of the liquid sample is drawn and the tangent line and one of the solid sample as the solid sample are drawn. The angle with the black rectangular portion 61 is measured with a protractor, and the receding dynamic contact angle θb of the receding liquid sample is measured (see FIG. 5A).

  Here, in FIG. 4 or FIG. 5, the position for measuring the liquid level of the liquid sample that moves forward and backward is the position farthest from the second opposing wall portions 13 and 14 made of a transparent body in the channel 10a (that is, It is the width direction center part P of the 1st opposing wall part 11 or 12 which consists of a solid sample (refer FIG. 6).

  Then, for example, the relationship between the interface velocity of the liquid sample moving forward and backward, the forward dynamic contact angle θa, and the backward dynamic contact angle θb is summarized as characteristic data of interface velocity-contact angle.

  As described above, in the dynamic contact angle measuring apparatus according to the present embodiment, the liquid sample is supplied to and recovered from the flow channel 10a of the measurement container 10 by the liquid supply / recovery means 20 within the flow channel 10a. The liquid sample can be advanced and retracted. Therefore, by adjusting the supply and recovery amount of the liquid sample from the liquid supply / recovery means 20 to the flow channel 10a of the measurement container 10, the moving speed of the liquid sample flowing in the flow channel 10a can be easily and reliably changed. be able to. Therefore, the liquid sample can be easily and reliably moved at high speed in the flow channel 10a of the measurement container 10. Then, the second opposing wall portion made of a transparent body is provided at the interface between the liquid sample and the first opposing wall portion 11 or 12 made of the solid sample on the liquid surface of the liquid sample moving at high speed in the flow path 10a. By photographing with the photographing means 30 via 13 or 14, the dynamic contact angle can be measured from the interface shape.

  Therefore, in the dynamic contact angle measurement device of the present embodiment, the dynamic contact angle at the interface between the liquid sample and the solid sample is stabilized even when the liquid sample moves at high speed in the flow path 10a of the measurement container 10. It becomes possible to measure.

  Moreover, in the dynamic contact angle measuring apparatus of this embodiment, the flow path 10a of the measurement container 10 is a slit-shaped flow path having a substantially rectangular cross section, and both the second opposing wall portions 13 and 14 in the slit-shaped flow path. The distance D between them is sufficiently larger than the distance d between the first opposing wall portions 11 and 12. For this reason, when measuring the dynamic contact angle at the interface between the solid sample and the liquid sample constituting the first opposing wall portions 11 and 12, the width direction central portion of the solid sample (that is, both the second opposing wall portions 13). The dynamic contact angle can be measured at a position P which is farthest from 14), and measurement with less error due to the influence of the second opposing wall portions 13 and 14 can be performed.

  Furthermore, in the dynamic contact angle measuring apparatus of the present embodiment, both the first opposing wall portions 11 and 12 are made of a solid sample, and one of the solid samples is made of a material constituting the fuel cell gas diffusion layer, and The other solid sample is made of a material constituting the fuel cell separator. Therefore, for example, if water is adopted as the liquid sample, the dynamic contact angle at the interface between each of the gas diffusion layer and the separator that partitions the flow path of water and gas in the fuel cell and the water as the liquid sample is shown by simulation. Can be measured.

  In addition, in the dynamic contact angle measuring device of the present embodiment, the measuring container 10 can be held by the holding means 40 in a state where the flow path 10a extends in an arbitrary angle direction with respect to the vertical direction. For this reason, it is possible to measure the dynamic contact angle at the interface between the liquid sample and the solid sample flowing in the flow path 10a extending in an arbitrary angle direction with respect to the vertical direction. Therefore, it is possible to measure the dynamic contact angle by arbitrarily changing the direction of gravity acting on the liquid sample flowing in the flow channel 10a.

  Further, in the dynamic contact angle measuring device of the present embodiment, the liquid supply / recovery stage 20 has the gas mixing means 24. For this reason, gas can be mixed in the liquid sample which flows in the flow path 10a in arbitrary ratios. Therefore, the dynamic contact angle at the interface between the liquid sample mixed with gas and the solid sample can be measured.

  In the dynamic contact angle measuring apparatus of the above embodiment, SUS is adopted as the solid sample constituting the first opposing wall portions 11 and 12, and the movement is performed without mixing gas from the gas mixing means 24 into the water as the liquid sample. It was repeated 3 times (N = 1 to 3) to collect the characteristic data of the interface velocity and the contact angle by measuring the target contact angle.

  The result is shown in FIG. In FIG. 7, the characteristic data plotted for ◯ is the first (N = 1) characteristic data, and the characteristic data plotted for □ is the second (N = 2) characteristic data plotted with Δ. Is characteristic data for the third time (N = 3).

  Further, in the dynamic contact angle measuring device of the above embodiment, SUS is adopted as a solid sample constituting the first opposing wall portions 11 and 12, and air is mixed into the water as the liquid sample from the gas mixing means 24, The dynamic contact angle was measured and the interface velocity-contact angle characteristic data was summarized. The results are also shown in FIG. In FIG. 7, the data plotted with x is characteristic data using water mixed with air as a liquid sample.

  From these results, it was confirmed that the dynamic contact angle can be measured satisfactorily even when the liquid sample moves forward and backward at a high speed of several m / second in the channel 10a.

It is a partial section lineblock diagram showing typically a schematic structure of a dynamic contact angle measuring device of this embodiment. It is a perspective view of a measurement container in a dynamic contact angle measuring device of this embodiment. It is sectional drawing of the measurement container in the dynamic contact angle measuring apparatus of this embodiment. When measuring the dynamic contact angle using the dynamic contact angle measuring device of the present embodiment, the image obtained by photographing the liquid surface of the liquid sample by the photographing means is binarized to show a state of monochrome display, (A) shows the case where the forward dynamic contact angle is measured, and (b) shows the case where the backward dynamic contact angle is measured. It is a partial cross section explaining the dynamic contact angle measured using the dynamic contact angle measuring apparatus of this embodiment, (a) shows the case where an advancing dynamic contact angle is measured, (b) is a backward dynamic. The case where the contact angle is measured is shown. It is a fragmentary sectional view explaining the measurement part in the liquid level of a liquid sample, when measuring a dynamic contact angle using the dynamic contact angle measuring device of this embodiment. It is a figure which shows the result which put together the characteristic data of the interface speed-contact angle in the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Measuring container 10a ... Flow path 11, 12 ... 1st opposing wall part 13, 14 ... 2nd opposing wall part 20 ... Liquid supply collection | recovery means 30 ... Imaging | photography means 40 ... Holding means

Claims (5)

A dynamic contact angle measuring device for measuring a dynamic contact angle at an interface between a solid sample and a liquid sample moving on the surface of the solid sample,
A measurement container having a flow path through which the liquid sample flows;
Liquid supply / recovery means for supplying and / or recovering the liquid sample to the flow path at an arbitrary flow rate;
Photographing means for photographing the liquid surface shape of the liquid sample flowing in the flow path,
A part of the measurement container is made of a transparent body, and a part of the inner surface of the measurement container defining the flow path is made of the solid sample, and the liquid sample on the liquid surface of the liquid sample flowing in the flow path A dynamic contact angle measuring apparatus configured to be able to photograph the interface between the solid sample and the solid sample from the outside through the transparent body with the photographing means. The measurement container has a pair of first opposing wall portions at least one of which is made of the solid sample and whose inner surfaces face each other in parallel, and a pair of second opposing wall portions at least one of which is made of the transparent body. ,
The flow path is a slit-shaped flow path having a substantially rectangular cross section defined by both the first opposed wall portions and the second opposed wall portions, and between the second opposed wall portions in the slit-shaped flow path. The dynamic contact angle measuring device according to claim 1, wherein the distance D is greater than the distance d between the first opposing wall portions.   Both of the first opposing wall portions are made of the solid sample, one of the solid samples is made of a material constituting a gas diffusion layer for a fuel cell, and the other solid sample is made of a material constituting a fuel cell separator. The dynamic contact angle measuring device according to claim 1 or 2, characterized by comprising:   4. The measurement container according to claim 1, wherein the measurement container is rotatable, and the measurement container is held in a state where the flow path extends in a direction at an arbitrary angle with respect to a vertical direction. The dynamic contact angle measuring device described in 1.   5. The liquid supply / recovery means includes gas mixing means for mixing gas at an arbitrary ratio into the liquid sample flowing in the flow path. Dynamic contact angle measuring device.

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