JP5315429B2 - Dynamic contact angle meter and method for measuring dynamic contact angle - Google Patents

Description

  The present invention relates to measurement of a contact angle used as an index indicating the wettability of a liquid with respect to a solid surface, and in particular, a dynamic that measures a dynamic contact angle that is a contact angle when a solid surface and a liquid move relative to each other. The present invention relates to a contact angle meter and a method for measuring a dynamic contact angle.

  Conventionally, the contact angle of a liquid on a solid surface is generally measured by dropping a predetermined amount of a liquid sample onto a flat solid sample and imaging from the side. That is, a droplet on a solid sample is imaged from the side by a CCD camera or the like, and an angle of a portion where the droplet contacts the surface of the solid sample is calculated based on a side image of the obtained droplet (for example, Patent Document 1). The contact angle measured by this method is a contact angle in a state where the liquid is stationary with respect to the solid surface, and is sometimes called a stationary contact angle.

  On the other hand, in fields such as spin coating and centrifugal dehydration, it is necessary to evaluate the wettability in a state where the liquid moves relative to the solid surface, that is, the solid-liquid interface moves. There is a dynamic contact angle as an index used for. There are two types of dynamic contact angles: an advancing contact angle that is a contact angle on the traveling direction side (front side) of the solid-liquid interface and a receding contact angle that is a contact angle on the opposite side (rear side) of the traveling direction. There is a contact angle.

  Measurement methods for dynamic contact angle include expansion / contraction methods that expand and contract droplets on a solid sample, sliding methods that tilt the solid sample and cause the droplets to slide on the solid surface (tumbling method), and liquid samples The Wilhelmy method, etc., in which a solid sample settles and floats inside is conventionally known. However, these measurement methods have a problem in that it is difficult to perform high-accuracy measurement stably depending on the properties of the solid sample and the liquid sample. In addition, it is difficult to measure the change in dynamic contact angle due to the difference in moving speed at the solid-liquid interface, that is, the speed dependency of the dynamic contact angle.

  On the other hand, a method for measuring a dynamic contact angle by inserting a needle tube into a droplet on a solid sample and moving the solid sample while holding the droplet by the needle tube has been proposed. (For example, refer to Patent Document 2).

JP 2002-277373 A Japanese Patent No. 3767500

  However, in the measurement method described in Patent Document 2, since the retention force of the droplet is determined by the adhesion force on the outer peripheral surface of the needle-shaped tube, depending on the type of the liquid sample and the combination with the solid sample, There was a problem that the liquid droplets were detached and measurement was impossible. For this reason, it is necessary not only to carefully select the material and surface treatment of the needle tube according to the properties and combination of the liquid sample and solid sample, but also to set the moving speed of the solid sample appropriately. It was very time consuming from the preparation stage.

  In this measurement method, the outer diameter of the needle-like tube is reduced to 1/2 or less of the outer diameter of the solid-liquid interface in order to prevent droplets from being drawn to the needle-like tube and floating from the solid sample. There is a problem that there is a limit to the retention force of the droplets. For this reason, when the solid sample is moved at a high speed, the liquid droplet is easily detached from the needle tube, and the moving speed of the solid-liquid interface capable of measuring the dynamic contact angle is limited. Therefore, it is still difficult to measure the speed dependency of the dynamic contact angle.

  Furthermore, since the outer diameter of the needle-like tube is limited to 1/2 or less of the outer diameter of the solid-liquid interface, the amount of deformation of the droplet accompanying the movement of the solid-liquid interface becomes large and is susceptible to disturbance. Therefore, there is a problem that it takes time from the start of movement of the solid sample to a stable state in which the dynamic contact angle can be measured. For this reason, for example, it is difficult to continuously measure the dynamic contact angle over a predetermined measurement range and obtain the distribution of the dynamic contact angle on the surface of the solid sample.

  In view of such circumstances, the present invention intends to provide a dynamic contact angle meter and a dynamic contact angle measurement method capable of stably measuring a dynamic contact angle under various conditions. is there.

(1) The present invention is arranged to face the measurement surface of the solid sample , and communicates with the facing surface facing the measurement surface, the outer peripheral surface of the facing surface that does not face the measuring surface, and the facing surface. Relative movement of the opposing member having the accommodating portion, the supply device for supplying the liquid sample between the measuring surface and the opposing member through the accommodating portion, and the solid sample and the opposing member in a direction substantially along the measuring surface A moving mechanism, an imaging device that images a liquid sample between the measurement surface and the opposing member from a direction substantially orthogonal to a relative movement direction of the solid sample and the opposing member, and the liquid sample in the storage unit. the imaging to said solid sample and the opposing member is relatively moved in a state of forming a cross-linked without contacting the outer peripheral surface between the liquid sample of the measuring surface and the opposing surface Location is characterized in that and a contact angle derivation device for deriving a dynamic contact angle on the basis of the image captured, a dynamic contact angle meter.

  (2) In the above (1), the moving mechanism may be configured such that the facing member is movable relative to the solid sample over a predetermined measurement range on the measurement surface. It is a dynamic contact angle meter of description.

(3) In the present invention, the contact angle deriving device may further include a dynamic contact angle for each of the plurality of measurement points based on an image of the opposing member passing through the plurality of measurement points set within the measurement range. The dynamic contact angle meter according to (2) above, characterized in that

(4) The present invention is also arranged to face the measurement surface of the solid sample, facing the measurement surface, an outer peripheral surface that does not face the measurement surface in the outer periphery of the facing surface, and communicates with the facing surface A method for measuring a dynamic contact angle using a facing member including a housing portion, wherein the facing member is disposed to face the measurement surface of the solid sample, and the measurement surface and the facing member are disposed through the housing portion. In the state where the liquid sample is supplied between the liquid sample and the liquid sample in the container, and the liquid sample continues to form a bridge between the facing surface and the measurement surface without contacting the outer peripheral surface. The sample and the facing member are relatively moved in a direction substantially along the measurement surface, and the liquid sample between the measurement surface and the facing member is moved to the solid sample and the facing member during the relative movement of the solid sample and the facing member. Serial characterized by measuring the dynamic contact angle is captured in the relative movement direction of the opposing member from a direction substantially perpendicular to a method of measuring a dynamic contact angle.

  (7) The method for measuring a dynamic contact angle according to (6) above, wherein the counter member is moved relative to the solid sample over a predetermined measurement range on the measurement surface. It is.

  (8) The dynamic contact angle measurement method according to (7), wherein the dynamic contact angle is measured for each of a plurality of measurement points set within the measurement range. is there.

  According to the dynamic contact angle meter and the dynamic contact angle measuring method according to the present invention, it is possible to achieve an excellent effect that the dynamic contact angle can be stably measured under various conditions.

(A) And (b) It is the schematic of the dynamic contact angle meter which concerns on embodiment of this invention. (A) And (b) It is the schematic which expanded and showed the front-end | tip part of the opposing member, and its periphery. (A)-(f) It is the schematic which showed the example of the other form of the opposing member. (A)-(e) It is the schematic which showed the measurement procedure of the dynamic contact angle. It is the schematic which showed the measurement procedure of (a) and (b) dynamic contact angle. (A)-(c) It is the schematic which showed the example of the other measuring method of a dynamic contact angle. It is the schematic which showed an example of the method of calculating | requiring the appropriate volume of (a)-(c) bridge | crosslinking.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  First, the dynamic contact angle meter 1 according to the embodiment of the present invention will be described. 1A and 1B are schematic views of a dynamic contact angle meter 1 according to the present embodiment. 1A is a front view of the dynamic contact angle meter 1, and FIG. 1B is a plan view of the dynamic contact angle meter 1. FIG.

  As shown in the figure, a dynamic contact angle meter 1 (hereinafter simply referred to as a contact angle meter 1) is disposed on a base 10, a stage 20 disposed on the base 10, and a side of the stage 20. The imaging device 30, the illumination device 40 disposed on the side of the stage 20 on the opposite side of the imaging device 30, the opposing member 50 disposed above the stage 20, and the supply device 60 connected to the opposing member 50. And a computer 70.

  This dynamic contact angle meter 1 forms a bridge 4 of the liquid sample 3 between the measurement surface 2a (upper surface) of the solid sample 2 and the opposing member 50, and in this state, the solid sample 2 and the opposing member 50 are connected to the measurement surface 2a. The dynamic contact angle of the solid sample 2 with respect to the liquid sample 3 is measured by relatively moving the sample along the axis.

  The base 10 is a member that supports the stage 20, the imaging device 30, the certification device 40, the supply device 60, and the like. In the present embodiment, these devices are arranged at appropriate positions via the brackets 12, 14 and the like. The base 10 includes a cover 16 that is made of a transparent material and covers the entire apparatus, and can maintain a constant measurement atmosphere such as temperature and humidity. In addition, the base 10 includes a leg portion 18 having a height adjusting mechanism in order to maintain the level of the upper surface of the stage 20.

  The stage 20 is a so-called XY stage on which the solid sample 2 is placed on the upper surface with the measurement surface 2a facing up. The shape of the solid sample 2 is not particularly limited as long as the shape has the measurement surface 2a. The stage 20 includes a moving mechanism 22 that moves the solid sample 2 in two directions (X and Y directions) orthogonal to each other in a horizontal plane, and a lifting mechanism 24 that moves the solid sample 2 up and down (moves in the Z direction). ing.

  The moving mechanism 22 moves the solid sample 2 in the X or Y direction, thereby relatively moving the solid sample 2 and the facing member 50 in a direction substantially along the measurement surface 2a. The moving mechanism 22 can move the solid sample 2 over a predetermined moving range in the X and Y directions by a known structure (not shown) such as a stepping motor and a ball screw transmission mechanism, and stops at an arbitrary position within the moving range. It is configured to be possible.

  Thereby, the moving mechanism 22 moves the opposing member 50 relative to the solid sample 2 over a predetermined measurement range A on the measurement surface 2a of the solid sample 2, and at an arbitrary relative position in the measurement range A. The opposing member 50 can be disposed. Further, the moving mechanism 22 can change the moving speed of the solid sample 2 in the X and Y directions, that is, the relative speed of the solid sample 2 and the facing member 50 within a predetermined speed range.

  The elevating mechanism 24 adjusts the distance between the solid sample 2 and the facing member 50 by moving the solid sample 2 in the Z direction. The elevating mechanism 24 can move the solid sample 2 over a predetermined movement range in the Z direction and can stop at any position within the movement range by a known structure (not shown) such as a stepping motor and a ball screw transmission mechanism. It is configured.

  The stage 20 operates under the control of the computer 70. The stage 20 may further include a rotation mechanism that rotates the solid sample 2 around the vertical direction (Z direction). Further, the stage 20 may further include a tilt mechanism that tilts the measurement surface 2a of the solid sample 2 with respect to the horizontal plane.

  The imaging device 30 images the liquid sample 3 (that is, the bridge 4) between the solid sample 2 and the facing member 50 from the side, and is configured by a CCD camera having a magnifying lens system in this embodiment. Yes. The imaging device 30 is controlled by the computer 70 to enlarge the bridge 4 and take an image, and transmits the image data to the computer 70. The computer 70 stores the image data received from the imaging device 30 in a predetermined storage unit (not shown) such as a hard disk or a flash memory and saves it. In addition, the imaging device 30 of this embodiment is arrange | positioned so that the bridge | crosslinking 4 may be imaged from a X direction.

  The illuminating device 40 illuminates the bridge 4 from behind when the imaging device 30 images the bridge 4 between the solid sample 2 and the facing member 50. The illumination device 40 includes a light source such as a halogen lamp or an LED, and is configured to emit light from the opposite side of the imaging device 30 toward the liquid sample 3 between the solid sample 2 and the facing member 50.

  The facing member 50 forms the bridge 4 of the liquid sample 3 between the measurement surface 2a of the solid sample 2 and holds the liquid sample 3 on which the bridge 4 has been formed, so that the liquid sample 3 is fixed to the solid sample 2. To move relative to each other. In the present embodiment, the facing member 50 is a cylindrical (tubular) member, and is arranged with one end (tip) in the axial direction facing the measurement surface 2a of the solid sample 2, and the other end (base end) is supplied. It is connected to the device 60.

  The supply device 60 supplies the liquid sample 3 between the facing member 50 and the measurement surface 2 a of the solid sample 2. The supply device 60 contains a predetermined amount of the liquid sample 3 and a cylinder (syringe) 62 to which the opposing member 50 is fixed, a plunger (piston) 64 inserted into the cylinder 62, and a drive mechanism that moves the plunger 64. 66.

  The supply device 60 is controlled by the computer 70 to move the plunger 64 to push out the liquid sample 3 from the cylinder 62 and supply the liquid sample 3 to the inside of the facing member 50. Then, the liquid sample 3 overflowing from the inside of the facing member 50 is supplied between the facing member 50 and the measurement surface 2a. That is, the supply device 60 and the opposing member 50 have a structure like a syringe, and the supply amount of the liquid sample 3 can be adjusted by adjusting the movement distance of the plunger 64.

  Although not shown, the supply device 60 is configured to be movable up and down (movable in the Z direction) under the control of the computer 70. Therefore, in this embodiment, the opposing member 50 is disposed at a measurement position where the tip is close to the measurement surface 2 a of the solid sample 2 by lowering the supply device 60, and the opposing member 60 is raised by raising the supply device 60. It is designed to be retracted from the measurement position.

  Although not shown, the computer 70 includes a CPU, storage means such as ROM, RAM, hard disk, and flash memory, display means such as a liquid crystal display, and input means such as a keyboard and a mouse. Yes. Further, the computer 70 includes a control unit 72 and an image processing unit 74 as a functional configuration realized by executing a program installed in the storage unit.

  The control means 72 controls the stage 20, the imaging device 30, the illumination device 40, the supply device 60, and the like. Then, the image processing means 74 processes the image picked up by the image pickup device 30 and derives the dynamic contact angle. In the present embodiment, the control unit 72 and the image processing unit 74 are realized by executing a program, but these devices may be configured by dedicated circuits. Further, the control means 72 and the image processing means 74 may be configured from dedicated computers, respectively.

  Next, details of the facing member 50 will be described. FIGS. 2A and 2B are schematic views showing the tip end portion of the opposing member 50 and its periphery in an enlarged manner. In FIGS. 2A and 2B, a part of the facing member 50 is shown in cross section.

  As described above, the facing member 50 is a cylindrical member disposed so that the annular tip surface 52 faces the measurement surface 2 a of the solid sample 2, and the inside of the facing member 50 is from the supply device 60. It is a supply passage 54 through which the liquid sample 3 passes. As shown in FIG. 5A, the liquid sample 3 supplied from the supply device 60 through the supply passage 54 forms a bridge 4 between the tip surface 52 and the measurement surface 2a.

  Thus, by forming the bridge 4 of the liquid sample 3 between the tip surface 52 and the measurement surface 2a, the liquid sample 3 can be prevented from being substantially in contact with the outer peripheral surface 56 of the facing member 50. Therefore, the liquid sample 3 can be stably held by the facing member 50. That is, in the present embodiment, the liquid sample 3 spreads on the outer peripheral surface 56 due to the wettability and adhesion of the outer peripheral surface 56, and the liquid sample 3 is attracted to the opposing member 50 side and separated from the measurement surface 2a. It is possible to prevent.

  Thereby, in this embodiment, it is possible to stably measure the dynamic contact angle in a wide range of combinations of the solid sample 2 and the liquid sample 3. In addition, even when the solid sample 2 and the opposing member 50 are relatively moved at a higher speed than before, the dynamic contact angle can be stably measured, so the dynamic contact angle can be measured over a wide speed range. It is possible to do. That is, in this embodiment, it is possible to measure the speed dependence of the dynamic contact angle, which has been difficult to measure conventionally.

  Further, in order to measure the dynamic contact angle, the liquid sample 3 needs to be deformed. In the present embodiment, since the deformed portion is composed of the bridge 4, the gap between the tip surface 52 and the measurement surface 2a is determined. By adjusting the distance L and the supply amount of the liquid sample 3, the deformed portion of the liquid sample 3 can be set to an optimum volume for measurement. Thus, in the present embodiment, by adjusting the volume of the bridge 4, it is possible to reduce unnecessary deformation and make it less susceptible to disturbance as compared with the conventional method using droplets. Therefore, the dynamic contact angle can be measured stably and with high accuracy.

  Further, in the present embodiment, the liquid sample 3 is partially accommodated in the supply passage 54 and is continuous with the liquid sample 3 in the supply passage 54 between the tip surface 52 and the measurement surface 2a. A bridge 4 is formed. That is, the supply passage 52 communicates with the tip surface 52 that is one surface on which the liquid sample 3 forms the bridge 4, and also serves as a storage portion 58 that stores the liquid sample 3 that is continuous (connected) with the bridge 4. It is functioning.

  Thus, by providing the accommodating part 58 in the opposing member 50, it becomes possible to increase the contact area of the liquid sample 3 and the opposing member 50 without touching the outer peripheral surface 56. Therefore, according to the property of the liquid sample 3. Therefore, a sufficient holding force (adhesive force) can be ensured. As a result, in this embodiment, it is possible to stably measure the dynamic contact angle in a wider range of combinations of the solid sample 2 and the liquid sample 3, and to stably adjust the dynamic contact angle over a wider speed range. Measurement can be performed.

  The distance L between the front end surface 52 of the facing member 50 and the measurement surface 2a of the solid sample 2 during measurement is not particularly limited as long as the liquid sample 3 can form the bridge 4. However, in order to eliminate the influence of the self-weight of the liquid sample 3 and to set the bridge 4 to an appropriate volume and perform measurement stably, the distance L during measurement is 30 to 70% of the outer diameter D1 of the facing member 50. It is preferable to be within the range.

  Further, the outer diameter D1 of the facing member 50 is not particularly limited, but the outer diameter D1 is within a range of 0.5 to 4 mm in order to stably perform the measurement with the bridge 4 as an appropriate volume. It is preferable that Further, the inner diameter D2 of the facing member 50 is not particularly limited, and may be appropriately determined according to the fluidity of the liquid sample 3, the strength and rigidity of the facing member 50, the area of the tip surface 52 required, and the like. Just decide.

  Moreover, the material of the opposing member 50 is not specifically limited, For example, the opposing member 50 can be comprised from appropriate materials, such as a metal, resin, rubber | gum, ceramics. Further, the facing member 50 may be subjected to a surface treatment such as various coatings. In the present embodiment, the facing member 50 is made of stainless steel.

  FIG. 4B shows a state in which the solid sample 2 is moved by the stage 20 and the solid sample 2, the facing member 50 and the liquid sample 3 are relatively moved, that is, the solid-liquid interface 5 between the solid sample 2 and the liquid sample 3. The state which moved relative to the solid sample 2 is shown. In FIG. 5B, since the solid sample 2 is moved toward the left side of the figure, the facing member 50, the liquid sample 3 and the solid-liquid interface 5 are relative to the solid sample 2 toward the right side of the figure. Will move.

  By this relative movement, the bridge 4 receives a shearing force and is deformed into a shape that is dragged by the solid sample 2, for example, and the contact angle θ1 on the traveling direction side (right side in the figure) of the solid-liquid interface 5 and the solid-liquid interface 5 The contact angle θ2 on the side opposite to the traveling direction (left side in the figure) changes. That is, since the contact angle θ1 becomes the advancing contact angle and the contact angle θ2 becomes the receding contact angle, the dynamic contact angle can be measured by measuring these two contact angles θ1 and θ2.

  As described above, in the present embodiment, since the liquid sample 3 on which the bridge 4 is formed can be reliably held on the facing member 50 and the volume of the bridge 4 can be appropriately set, the response speed of deformation of the bridge 4 can be increased. It is possible to increase. Therefore, in this embodiment, while shortening the run period until the bridge | bridging 4 will be in the state which can measure a dynamic contact angle from the start of the relative movement of the solid sample 2 and the opposing member 50, the measurement surface 2a in relative movement It is possible to follow the deformation of the bridge 4 in a sensitive manner with respect to changes in the properties. As a result, in the present embodiment, the dynamic contact angle can be measured over substantially the entire measurement surface 2a of the solid sample 2, and the distribution of the dynamic contact angle on the measurement surface 2a can be precisely determined. Yes.

  3A to 3F are schematic views illustrating examples of other forms of the facing member 50. FIG. In addition, in the same figure (a)-(f), a part of opposing member 50 is shown in the cross section. The opposing member 50 may be provided with a plurality of supply passages 54 (accommodating portions 58), for example, by a double tube or a lotus root structure, as shown in FIG. Moreover, the opposing member 50 may be configured by bundling a plurality of tubes, as shown in FIG. Further, the facing member 50 may be configured such that the supply passage 54 (accommodating portion 58) and the tip end surface 52 communicate with each other through a hole 54a having a smaller diameter than the supply passage 54. In this case, the area of the front end surface 52 can be adjusted by adjusting the number of the holes 54a.

  Further, depending on the properties of the solid sample 2 and the liquid sample 3, the opposing member 50 may be formed of a solid member as shown in FIGS. In this case, the supply device 60 may be configured to supply the liquid sample 3 from the side between the solid sample 2 and the facing member 50.

  As described above, when the opposing member 50 is formed of a solid member, an appropriate uneven shape 52a may be provided on the distal end surface 52 as shown in FIG. ), A recess may be formed in the distal end surface 52 to provide the accommodating portion 58. When providing the accommodating part 58, the number, volume, and shape of the accommodating part 58 are not specifically limited, What is necessary is just to set suitably according to the property etc. of the liquid sample 3. FIG. Therefore, the opposing member 50 may be one in which the supply passage 54 (accommodating portion 58) does not communicate with the supply device 60 in the example shown in FIGS.

  Moreover, although illustration is abbreviate | omitted, the opposing member 50 may be comprised from porous bodies, such as resin, ceramics, a nonwoven fabric, for example. In this case, the voids of the porous body can function as the supply passage 54 or the accommodating portion 58. Also, from a composite of a material other than a porous body and a porous body, such as a porous body disposed inside a tubular member, or a porous body plate attached to the tip of a solid member You may make it comprise the opposing member 50. FIG.

  The shape of the facing member 50 is not limited to the above-described shape, and any shape can be used as long as the bridge 4 of the liquid sample 3 can be formed between the tip surface 52 and the measurement surface 2a of the solid sample 2. Such a shape may be used. Moreover, the shape of the front end surface 52 is not particularly limited, and an arbitrary shape such as a polygonal shape or an elliptical shape can be adopted in addition to a circular shape or a circular tube shape.

  Next, the measurement procedure of the dynamic contact angle by the dynamic contact angle meter 1 will be described. 4 (a) to 4 (e) and FIGS. 5 (a) and 5 (b) are schematic diagrams showing a procedure for measuring the dynamic contact angle. FIGS. 4A to 4E are enlarged views of the distal end portion of the opposing member 50 and its periphery. 5A is a diagram of the solid sample 2 viewed from above, and FIG. 5B is a diagram of the solid sample 2 and the opposing member 50 viewed from the imaging device 30 side.

  In the measurement of the dynamic contact angle, first, the liquid sample 3 is accommodated in the supply device 60, the solid sample 2 is placed on the stage 20, and then the stage 20 is moved to measure the solid sample 2 on the measurement surface 2a. The facing member 50 is disposed at the starting point S (see FIG. 5A).

  Next, as shown in FIG. 4A, the supply device 60 is lowered to place the facing member 50 at the measurement position. The measurement position of the facing member 50 is set to a position where the liquid sample 3 can form the bridge 4 between the front end surface 52 of the facing member 50 and the measurement surface 2 a of the solid sample 2. Next, as shown in FIG. 4B, the supply device 60 is operated to supply the liquid sample 3 between the facing member 50 and the solid sample 2, and the tip surface 52 of the facing member 50 and the solid sample 2 are A bridge 4 of the liquid sample 3 is formed between the measurement surfaces 2a.

  After the bridge 4 is formed, as shown in FIG. 4C, the position of the plunger 64 of the supply device 60 is changed as necessary, and the liquid sample 3 between the tip surface 52 and the measurement surface 2a is changed. By adjusting the amount or by moving the stage 20 up and down to adjust the distance between the distal end surface 52 and the measurement surface 2a, the bridge 4 has an appropriate volume. At this time, it is preferable to prevent the liquid sample 3 from coming into contact with the outer peripheral surface 56 of the facing member 50 for stable measurement.

  FIG. 4D shows an example in which the bridge 4 has an appropriate volume, that is, a volume that can be appropriately held by the facing member 50 during measurement. The appropriate volume of the bridge 4 is not limited to a shape in which the outer peripheral portion shown in FIG. 4 (d) is slightly depressed, and depending on the properties of the liquid sample 3 and the solid sample 2, In some cases, the outer peripheral portion shown in 2 (a) has a slightly bulging shape or a shape closer to a droplet.

  Whether or not the bridge 4 has an appropriate volume can be confirmed by an image captured by the imaging device 30. In addition, the determination as to whether or not the bridge 4 has an appropriate volume may be made by the measurer visually observing the image displayed on the display means of the computer 70, or by comparison with the template by the image processing means 74. It may be automatically performed by such as.

  If the bridge 4 is appropriately formed, as shown in FIG. 4E, the stage 20 is moved in the Y direction at a predetermined measurement speed, and the solid sample 2 and the opposing member 50 (and the bridge 4) are predetermined. The deformation state of the bridge 4 is imaged by the imaging device 30 while being relatively moved at the measurement speed. Then, the forward contact angle θ1 and the backward contact angle θ2 are derived by subjecting the captured image to image processing by the image processing means 74. The derivation of the advancing contact angle θ1 and the receding contact angle θ2 can be performed by an existing method for deriving the contact angle from the image, such as a tangent method or a curve fitting method.

  Note that the tangent method is a method for obtaining the center of a circle by assuming the contour shape in the vicinity of the solid-liquid interface 5 of the bridge 4 as a part of a circle, and obtaining the angle formed by the straight line and the straight line as the contact angle. . The curve fitting method assumes that the contour shape in the vicinity of the solid-liquid interface 5 of the bridge 4 forms a perfect circle or a part of an ellipse, and uses all observation coordinates within the specified section (fitting section). In this method, a perfect circle or ellipse parameter is determined by performing least squares fitting, and a contact angle is calculated by obtaining a differential coefficient at an end point.

  As shown in FIGS. 5A and 5B, the movement of the stage 20 in the Y direction is such that the opposing member 50 moves relative to the Y direction dimension Ay of the measurement range A from the measurement start point S, and the measurement end point E is reached. It is done until it reaches. While the stage 20 is moved in the Y direction, that is, while the solid sample 2 and the opposing member 50 are relatively moved in the Y direction, the imaging device 30 continues to capture images, and the captured images are stored in the computer 70 as necessary. Displayed on the display means.

  Then, the image processing unit 74 acquires the image captured by the imaging device 30 at a predetermined sampling period, and associates the acquired image with the position information (X coordinate and Y coordinate) of the facing member 50 in the measurement range A. And stored in the storage means of the computer 70. Note that the sampling period for acquiring the image is determined by the setting of the interval Py in the Y direction of the measurement point P at which the dynamic contact angle is measured and the moving speed of the stage 20 in the Y direction (that is, the setting of the measurement speed). . Further, the position information of the facing member 50 can be acquired from the control information of the stage 20, for example.

  Thereby, the image of the bridge | crosslinking 4 in the measurement point P for every space | interval Py of the Y direction is obtained over the Y direction dimension Ay of the measurement range A. Then, by performing image processing on these images, the forward contact angle θ1 and the backward contact angle θ2 at each measurement point P are obtained over the Y-direction dimension Ay of the measurement range A.

  Note that the derivation of the forward contact angle θ1 and the backward contact angle θ2 may be performed every time an image is acquired, or may be performed collectively later. The derived forward contact angle θ1 and reverse contact angle θ2 are stored in the storage means of the computer 70 in association with the position information of the facing member 50, and displayed on the display means as necessary.

  Thereafter, the above procedure is repeated after the stage 20 is moved by the distance Px in the X direction of the measurement point P. When the above procedure is repeated over the X direction dimension Ax of the measurement range A, The measurement ends. Note that the Y-direction interval Py between the measurement start point S and the first measurement point P and the Y-direction interval Py between the last measurement point P and the measurement end point E are larger than the other Y-direction intervals Py. It may be narrowed and a wider range in the Y direction may be measured. Further, the interval Px in the X direction and the interval Py in the Y direction of the measurement points P may be the same interval or different intervals.

  By the above procedure, the two-dimensional distribution of dynamic contact angles (advance contact angle θ1 and receding contact angle θ2) in measurement range A is measured. Further, by performing measurement while changing the measurement speed (that is, the movement speed of the stage 20 in the Y direction), a two-dimensional distribution of dynamic contact angles can be obtained for each movement speed of the solid-liquid interface.

  As described above, in the present embodiment, since the bridge 4 can be stably held, the two-dimensional distribution of the dynamic contact angle can be measured over a wide speed range. Therefore, according to the dynamic contact angle meter 1 of the present embodiment, the wettability of the liquid sample 3 with respect to the solid sample 2 can be evaluated from a more detailed and multifaceted viewpoint than ever before.

  The method for measuring the dynamic contact angle is not limited to the above example. 6A to 6C are schematic views illustrating examples of other methods for measuring the dynamic contact angle. In the measurement of the dynamic contact angle, for example, as shown in FIG. 5A, the dynamic contact angle is set along the zigzag measuring path by alternately changing the moving direction of the stage 20 in the Y direction. You may make it measure.

  Further, as shown in FIG. 5B, the dynamic contact angle is measured along the spiral measurement path by combining the movement of the stage 20 in the X direction and the rotation around the Z axis. May be. In this case, the dynamic contact angle may be measured from the outside of the measurement surface 2a of the solid sample 2 toward the center as shown in FIG. The dynamic contact angle may be measured toward the outside. In this case, a disk-shaped solid sample 2 may be used.

  Alternatively, the dynamic contact angle meter 1 may be provided with a plurality of imaging devices 30 so that the bridge 4 is imaged from a plurality of directions during the relative movement of the solid sample 2 and the facing member 50. In this case, for example, as shown in FIG. 5C, in addition to the direction substantially orthogonal to the relative movement direction of the solid sample 2 and the facing member 50 (that is, the X direction), the same direction as the relative movement direction (that is, the X direction) By taking an image from (Y direction), it becomes possible to grasp the deformation state of the bridge 4 during relative movement in more detail. That is, the wettability of the liquid sample 3 with respect to the solid sample 2 can be evaluated from a more detailed and multifaceted viewpoint. Needless to say, imaging may be performed from a direction other than the example shown in FIG.

  Next, an example of a method for obtaining an appropriate volume of the bridge 4 will be described. FIGS. 7A to 7C are schematic views showing an example of a method for obtaining an appropriate volume of the bridge 4, and are enlarged views of the distal end portion of the opposing member 50 and the periphery thereof.

  In this example, first, as shown in FIG. 2A, a larger liquid sample 3 is supplied between the facing member 50 and the solid sample 2 to form a larger bridge 4. Next, as shown in FIG. 4B, the stage 20 is operated to move the solid sample 2 at a predetermined measurement speed, and as shown in FIG. Separate as drops 6. At this time, it can be estimated that the cross-linking 4 remaining between the facing member 50 and the solid sample 2 has a volume that the facing member 50 can stably hold at the measurement speed.

  In this way, an appropriate volume of the bridge 4 can be determined. Note that the solid sample 2 may be moved a longer distance to separate the plurality of droplets 6. Further, the volume obtained in this way may be finely adjusted according to the measurement situation or the like. Needless to say, the method for obtaining an appropriate volume of the bridge 4 is not limited to the above-described example, and other methods may be used.

  As described above, the dynamic contact angle meter 1 according to the present embodiment includes the facing member 50 disposed to face the measurement surface 2a of the solid sample 2, and the liquid sample between the measurement surface 2a and the facing member 50. 3, a moving mechanism 22 for relatively moving the solid sample 2 and the opposing member 50 in a direction substantially along the measurement surface 2 a, and the liquid sample 3 between the measurement surface 2 a and the opposing member 50 as the solid sample 2. And a dynamic contact angle (advanced contact) based on an image captured by the imaging device 30 during the relative movement of the solid sample 2 and the opposing member 30. A contact angle deriving device (image processing means 74) for deriving the angle θ1 and the receding contact angle θ2), and the facing member 50 moves the solid sample 2 and the facing member 50 relative to each other to move the measurement surface 2a and the facing member 50. Between When the liquid sample 3 is imaged, the liquid sample 3 is disposed at a position where the cross-link 4 is formed between the measurement surface 2a and the surface facing the measurement surface 2a of the facing member 50 (tip surface 52).

  By adopting such a configuration, it becomes possible to hold the liquid sample 3 more stably than before by the facing member 50, so that the dynamic contact angle can be stably measured under various conditions. it can. That is, the dynamic contact angle can be stably measured in a wide range of combinations of the solid sample 2 and the liquid sample 3, and the dynamic contact angle can be stably measured over a wide speed range. ing.

  Further, the moving mechanism 22 is configured such that the opposing member 50 can move relative to the solid sample 2 over a predetermined measurement range A on the measurement surface 2a. By doing so, it becomes possible to measure the dynamic contact angle over a wider range in the measurement surface 2a, so that the wettability of the liquid sample 3 with respect to the solid sample 2 is more detailed and multifaceted than before. Can be evaluated from various perspectives.

  Further, the contact angle deriving device (image processing means 74) is based on the image of the opposing member 50 passing through the plurality of measurement points P set in the measurement range A, and the dynamic contact angle for each of the plurality of measurement points P. Is derived. In this way, it is possible to measure the two-dimensional distribution of the dynamic contact angle within the measurement range A, so that the wettability of the liquid sample 3 with respect to the solid sample 2 is more detailed and multifaceted. Can be evaluated from.

  The opposing member 50 includes an accommodating portion 58 that accommodates the liquid sample 3, and the accommodating portion 58 is communicated with a surface facing the measurement surface 2a. By doing so, it becomes possible to increase the holding force of the liquid sample 3, so that stable measurement can be performed even at a higher measurement speed than before.

  The supply device 60 is configured to supply the liquid sample 3 between the measurement surface 2a and the facing member 50 through the storage portion 58 (supply passage 54). Thus, by using the supply passage 54 also as the accommodating portion 58, the holding force of the liquid sample 3 can be stably increased while the opposing member 50 and the supply device 60 are simply configured.

  In the method for measuring the dynamic contact angle according to the present embodiment, the facing member 50 is arranged to face the measuring surface 2a of the solid sample 2, and the liquid sample 3 is supplied between the measuring surface 2a and the facing member 50. The solid sample 2 and the opposing member 50 are substantially aligned with the measuring surface 2a in a state where the liquid sample 3 forms a bridge 4 between the measuring surface 2a and the surface (front end surface 52) facing the measuring surface 2a of the opposing member 50. The liquid sample 3 between the measurement surface 2a and the opposing member 50 is moved from the direction substantially orthogonal to the relative moving direction of the solid sample 2 and the opposing member 50 during the relative movement of the solid sample 2 and the opposing member 50. Image and measure dynamic contact angle.

  By adopting such a configuration, it becomes possible to hold the liquid sample 3 more stably than before by the facing member 50, so that the dynamic contact angle can be stably measured under various conditions. it can.

  In the method for measuring a dynamic contact angle according to the present embodiment, the opposing member 50 is moved relative to the solid sample 2 over a predetermined measurement range A on the measurement surface 2a. By doing so, it becomes possible to measure the dynamic contact angle over a wider range in the measurement surface 2a, so that the wettability of the liquid sample 3 with respect to the solid sample 2 is more detailed and multifaceted than before. Can be evaluated from various perspectives.

  In the dynamic contact angle measurement method according to the present embodiment, the dynamic contact angle is measured for each of the plurality of measurement points P set in the measurement range A. In this way, it is possible to measure the two-dimensional distribution of the dynamic contact angle within the measurement range A, so that the wettability of the liquid sample 3 with respect to the solid sample 2 is more detailed and multifaceted. Can be evaluated from.

  Although the embodiment of the present invention has been described above, the dynamic contact angle meter and the dynamic contact angle measuring method of the present invention are not limited to the above-described embodiment, and do not depart from the gist of the present invention. Of course, various changes can be made within the range.

  For example, in the above-described embodiment, the example in which the solid sample 2 and the facing member 50 are moved relative to each other by moving the solid sample 2 with respect to the facing member 50 in the stationary state has been described, but the present invention is limited to this. Instead, the opposing member 50 may be moved relative to the solid sample 2 in a stationary state, or both the solid sample 2 and the opposing member 50 may be moved in the opposite directions. When the opposing member 50 is moved, the opposing member 50 may be moved within the imaging range of the imaging device 30, or the imaging device 30 may be moved together with the opposing member 50.

  Moreover, although the example which moves the solid sample 2 and the opposing member 50 relatively in a horizontal plane was shown in the said embodiment, this invention is not limited to this, The solid sample 2 and the opposing member 50 are in a vertical plane. May be moved relative to each other, or may be moved relatively within an inclined plane. Alternatively, the solid sample 2 may be disposed with the measurement surface 2a facing downward, and the opposing member 50 may be opposed from below.

  Moreover, although the example in the case where the measurement surface 2a of the solid sample 2 is configured from a flat surface is shown in the above embodiment, the present invention is not limited to this, and the measurement surface 2a is configured from a curved surface. It may be. In this case, the opposing member 50 or the solid sample 2 may be raised and lowered along the curved surface during the relative movement, and the distance between the solid sample 2 and the opposing member 50 may be kept substantially constant.

  In addition, the operations and effects in the above-described embodiment are merely a list of the most preferable operations and effects resulting from the present invention, and the operations and effects according to the present invention are not limited to these.

  The dynamic contact angle meter and the dynamic contact angle measurement method of the present invention can be used in the field of measurement and evaluation of surface properties of solids.

DESCRIPTION OF SYMBOLS 1 Dynamic contact angle meter 2 Solid sample 2a Measurement surface 3 Liquid sample 4 Bridge | crosslinking 20 Stage 22 Movement mechanism 30 Imaging device 50 Opposing member 52 Front end surface 54 Supply path 58 Storage part 60 Supply device 70 Computer 74 Image processing means A Measurement range P Measurement point θ1 Forward contact angle θ2 Backward contact angle

Claims (6)

A facing member that is disposed to face the measurement surface of the solid sample and that faces the measurement surface; an outer peripheral surface that does not face the measurement surface at an outer periphery of the facing surface; and a housing member that communicates with the facing surface ; ,
A supply device for supplying a liquid sample between the measurement surface and the opposing member through the accommodating portion;
A moving mechanism for relatively moving the solid sample and the facing member in a direction substantially along the measurement surface;
An imaging device that images a liquid sample between the measurement surface and the opposing member from a direction substantially orthogonal to the relative movement direction of the solid sample and the opposing member;
While the liquid sample continuous with the liquid sample in the storage portion forms a bridge between the facing surface and the measurement surface without contacting the outer peripheral surface, the solid sample and the facing member are in relative movement. A contact angle deriving device for deriving a dynamic contact angle based on an image captured by the imaging device,
Dynamic contact angle meter. The moving mechanism is configured such that the facing member is movable relative to the solid sample over a predetermined measurement range on the measurement surface.
The dynamic contact angle meter according to claim 1. The contact angle deriving device derives a dynamic contact angle for each of the plurality of measurement points based on an image of the opposing member passing through the plurality of measurement points set within the measurement range. ,
The dynamic contact angle meter according to claim 2 . An opposing member that is disposed to face the measurement surface of the solid sample, and that has an opposing surface that opposes the measurement surface, an outer peripheral surface that does not oppose the measurement surface in an outer periphery of the opposing surface, and a housing portion that communicates with the opposing surface. A method for measuring the dynamic contact angle used,
Placing the facing member facing the measurement surface of the solid sample,
Supplying a liquid sample between the measurement surface and the opposing member through the accommodating portion;
In the state in which the liquid sample continuous with the liquid sample in the housing portion forms a bridge between the facing surface and the measuring surface without contacting the outer peripheral surface, the solid sample and the facing member are placed on the measuring surface. Relative movement in the direction along
During the relative movement of the solid sample and the opposing member, the liquid sample between the measurement surface and the opposing member is imaged from a direction substantially perpendicular to the relative movement direction of the solid sample and the opposing member to obtain a dynamic contact angle. Characterized by measuring,
Dynamic contact angle measurement method. The opposed member is moved relative to the solid sample over a predetermined measurement range on the measurement surface,
The method for measuring a dynamic contact angle according to claim 4 . The dynamic contact angle is measured for each of a plurality of measurement points set within the measurement range,
The method for measuring a dynamic contact angle according to claim 5 .

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