JP2010078394A - Simple zeta potential measuring instrument and zeta potential measuring method - Google Patents

Abstract

[PROBLEMS] To use a zeta potential, which has become more important with the development of interface science, to make it possible to measure zeta potential at low cost and easily using a commonly used microscope. It has been.
The zeta potential measuring device for microscopic observation is an inexpensive closed-type electrophoresis cell, and a substantially cylindrical plug member having an electrode for applying a DC electric field, and the plug member is attached and detached. A cylindrical opening tank portion that is freely received and a flat rectangular parallelepiped electrophoresis tank cavity that communicates with the opening of the opening tank section are provided at the center and are integrated with the opening tank section. It is composed of a rectangular parallelepiped-shaped flat glass electrophoresis cell, and the opening tank part is arranged at both end sides of the electrophoresis tank cavity, using the apparatus, The zeta potential can be measured easily, accurately, and with a simple operation with a common microscope.
[Selection] Figure 1

Description

  The present invention relates to a simple zeta potential measuring device and a zeta potential measuring method.

Analysis of the surface / interface of a solid is becoming increasingly important from the viewpoint of evaluation and utilization of various functions. There are limited methods for evaluating the surface of a solid in a solution, and zeta potential measurement is most commonly used. The zeta potential is the most important interfacial electrical phenomenon from a practical point of view. It is related to all interfacial electrical phenomena such as electrophoresis, electroosmosis, and streaming potential, and has a dominant influence on dispersion stability. give.
The zeta potential is a value representing a charged state of a surface such as dispersed particles or colloidal particles in a solution, and is used as an indicator of dispersion or aggregation in the solution. Looking at the solids in the water, when the solid moves in the water, water molecules are generally strongly bound to the surface of the solid. The potential at this slip plane is called “zeta potential” (ζ potential). Since the zeta potential is the potential that appears for the first time when the two phases move relatively, it is also called the “electrokinetic potential”.
Regarding zeta potential, Junnosuke Usui, “Electrophoresis and Interfacial Potential-1”, Metals, Vol. 70 (2000) No. 11, pp.993-998 (Non-patent Document 1) and Junnosuke Usui, “Electrophoresis and Interfacial Potential” Potential-2 "
, Metals, Vol. 70 (2000) No. 12, pp. 1093-1098 (Non-Patent Document 2).

The zeta potential is a physical quantity that evaluates the properties of the interface, and is an index especially for evaluating the dispersibility / aggregation of colloids, interactions, and surface modification. It is used in various industries such as agent manufacturing, dyeing and adsorption, paper, pulp, textile industry, water quality management such as water and sewage, washing water, flotation, biotechnology, food industry, etc. .
As the zeta potential measurement method, electrophoresis method, electroosmosis method, streaming potential method, streaming current method, sedimentation potential method, ultrasonic potential method or ultrasonic vibration potential (UVP) method,
Examples include electrokinetic sonic amplitude (ESA) method. The electrophoresis method
A constant DC electric field is applied to the solution, and the velocity of particles migrating in the electric field is measured. The migrating particles are usually observed with an optical microscope or an ultramicroscope. Recently, however, new electrophoretic mobility measurement techniques have been developed. For example, methods using the Doppler effect and rotation Although devices using the diffraction grating method are commercially available, both are expensive devices.
Further, what is disclosed in Japanese Patent Laid-Open No. 5-312757 (Patent Document 1) is a sample for measuring a zeta potential generated at a solid-liquid interface between a solid phase surface such as a plate material and a liquid. It is intended to be used for measurement without pulverizing the plate material as it is, and a double-sided adhesive tape is placed between the transparent migration cell and the actual product to maintain the measurement solution seal. The zeta potential is measured by forming an electrophoresis tank in the plane of the transparent migration cell and the actual product. That is, the sample to be measured is a solid and not a liquid.

JP-A-5-312757 Usui Junnosuke, “Electrophoresis and Interfacial Potential-1”, Metals, Vol. 70 (2000) No. 11, pp.993-998 Usui Junnosuke, “Electrophoresis and Interfacial Potential-2”, Metals, Vol. 70 (2000) No. 12, pp.1093-1098

With the development of interface science, the use of zeta potential has become increasingly important, and the need for zeta potential measurement has increased. However, commercially available zeta electrometers are quite expensive and cannot be measured easily.
In the present invention, a commonly used microscope is used to measure the zeta potential of fine particles relatively easily and inexpensively, and to accurately measure the zeta potential of various fine particles. The object is to provide an inexpensive device that makes possible.

  The inventors of the present invention have intensively studied to solve the above problems, and using an inexpensive closed-system electrophoresis cell, with a popular general microscope, easily and accurately, with a simple operation, It has been found that zeta potential can be measured. The present invention has been completed based on such findings.

The present invention provides the following.
[1] A substantially cylindrical plug member provided with an electrode for applying a DC electric field, a cylindrical open tub portion that removably receives the plug member, and a flat shape communicating with the opening of the open tub portion A rectangular parallelepiped flat-plate glass electrophoresis cell having a rectangular parallelepiped electrophoresis tank cavity at the center and integrated with the open tank part, the open tank part being the electrophoresis A zeta potential measuring device for microscopic observation, wherein two zeta potential measuring devices are arranged at both ends of the tank cavity.
[2] A flat rectangular parallelepiped hollow box cell, the bottom surface of which has a flat rectangular bottom surface suitable for placement on a microscope observation sample stage, and the top surface of the cell on the microscope objective lens side There is a rectangular plane having the same shape as the bottom surface, and is made of a translucent member. The cell has a hollow portion for accommodating an observation sample in the central portion, and communicates with the hollow portion. And has a bathtub for receiving the liquid sample for measurement, and the two bathtubs are provided on the upper surface of each end side along the long axis of the cell. The zeta potential measuring device for microscopic observation according to the above [1], wherein a plug member having an electrode for applying a DC electric field is detachably mounted.

[3] A synthetic quartz slide glass is used, and a rectangular component at the center of the slide glass is cut out to produce an intermediate component that is a member made of a square frame. Cut out two circular holes centered on the inner side of each end of the axis along the long axis of the slide and at the center of the axis along the short axis. A member having two holes near the short side is obtained, and a cylindrical synthetic quartz pipe is attached to the hole so that the center points of the circles coincide with each other. An upper part constituent member that is a receiving tank and that has an electrode plug receiving port is manufactured, and then a synthetic quartz slide glass is used as a bottom constituent member, and the intermediate part constituent member is overlaid thereon. Pasted, and then In addition, an electrophoresis cavity constituted by stacking and laminating the above-prepared upper part constituent members, an electrophoresis cell having a sample receiving tank connected therewith and two electrode plug receiving ports, and a palladium electrode are provided. The zeta potential measuring device for microscopic observation according to the above [1] or [2], comprising two fluororesin stoppers.
[4] A zeta potential measurement method comprising observing particles with a microscope using the zeta potential measurement device for microscopic observation according to any one of [1] to [3].
[5] The zeta potential measurement method according to the above [4], which includes performing moving image processing, binarization processing, and / or image synthesis processing on an image obtained through a microscope.

If the apparatus of this invention is used, the zeta potential measurement of microparticles | fine-particles can be performed comparatively easily and cheaply using the microscope which has spread widely. The zeta potential measuring device for microscopic observation of the present invention has a simple structure and is inexpensive, and enables zeta potential measurement of fine particles using an existing optical microscope. With the technique of the present invention, it is possible to easily and accurately measure the zeta potential using a general microscope that is widespread.
Other objects, features, excellence and aspects of the present invention will be apparent to those skilled in the art from the following description. However, it is understood that the description of the present specification, including the following description and the description of specific examples and the like, show preferred embodiments of the present invention and are presented only for explanation. I want. Various changes and / or modifications (or modifications) within the spirit and scope of the present invention disclosed herein will occur to those skilled in the art based on the following description and knowledge from other parts of the present specification. Will be readily apparent. All patent documents and references cited herein are cited for illustrative purposes and are not to be construed as a part of this specification. is there.

The present invention provides a simple zeta potential measurement device and a zeta potential measurement method.
The simple zeta potential measuring device of the present invention has a very simple structure, is easy to handle, can be manufactured at low cost, and enables reliable zeta potential measurement.
The present invention makes it possible to measure the zeta potential of various fine particles relatively easily and inexpensively by devising the shape of the electrophoresis cell and the electrode and using a commercially available microscope.
The simple zeta potential measuring device of the present invention has a shape suitable for mounting on a normal optical microscope observation sample stage, and a substantially cylindrical plug member provided with an electrode for applying a DC electric field; A cylindrical opening tank portion that removably receives the plug member, and a flat rectangular parallelepiped electrophoresis tank cavity that communicates with the opening of the opening tank portion at the center and integrated with the opening tank portion It is characterized by comprising a rectangular parallelepiped flat glass electrophoresis cell, and two opening tank portions are arranged at both end sides of the electrophoresis tank cavity.
A typical form of the simple zeta potential measuring device of the present invention is a flat rectangular hollow box cell, and the bottom surface of the cell has a flat rectangular bottom surface suitable for mounting on a sample stage for microscopic observation. And the top surface of the cell is on the microscope objective lens side, has a rectangular plane that is the same shape as the bottom surface, and is made of a light-transmitting member, and the cell is for accommodating an observation sample in the center. A hollow portion that has a bathtub that communicates with the hollow portion and receives a liquid sample for measurement; two bathtubs are provided on the upper surface of each end along the long axis of the cell; A plug member having an electrode for applying a DC electric field is detachably attached to the upper opening of the bathtub.
The member constituting the upper surface on the microscope objective lens side and the member constituting the flat rectangular bottom surface suitable for placement on the sample stage for microscope observation may be preferably a slide glass or a glass plate of the same quality.
The simple zeta potential measurement apparatus of the present invention may be a system that can be used in combination with, for example, analysis software, a CCD camera for a microscope, and a DC stabilized power supply in a zeta potential measurement method using the same.

In the simple zeta potential measurement device of the present invention, the main body of the flat rectangular parallelepiped hollow box cell can be produced as follows. That is, three slide glasses for a microscope are prepared, and the center portion of one glass is cut into a rectangular shape to give a frame material surrounding a hollow portion capable of receiving a liquid sample. The frame-shaped member (intermediate part constituting member) obtained in this way is laminated with another two slide glasses so as to be sandwiched from above and below. The slide glass (upper part constituent member) disposed on the upper side is subjected to the following processing in advance. That is, the upper slide glass is rounded so that the holes are in contact with both end portions (end portions along the long axis) of the cutout portion inside the frame member and the hole portions are located on the side corresponding to the cutout portion. A hole is formed by cutting out, and a hollow cylindrical member that is sized to fit the hole that is drilled is attached. As the hollow cylindrical member, a glass tube cut can be used. As for the hollow cylindrical member, the cut surface can be polished as appropriate. The hollow cylindrical member attached to the upper slide glass functions as a liquid tank for receiving the liquid sample, and can receive and seal the stopper member. Commercially available slide glasses for glass (bottom component members), which are constituent members disposed below, can be used as they are.

Examples of the microscope slide glass used for constituting the simple zeta potential measuring device of the present invention include those having a length of 76 mm × width of 26 mm × thickness of 0.9 to 1.2 mm. The thickness of the slide glass varies, for example, 0.8-1.0 mm, 1.0-1.2 mm, 1.2-1.5 mm, 1.3
It may be mm. Moreover, in the large sized glass slide, the size is, for example, a length of 76 mm × width of 52 mm. A typical microscope slide is 76 mm long x 26 mm wide x 0.9-1.2 mm thick.

Next, FIG. 1 shows a simple zeta potential measuring device of the present invention, that is, an electrophoresis cell and an electrode plug. A method for producing this simple zeta potential measuring apparatus using a slide glass having a typical size: length 76 mm × width 26 mm × thickness 0.9 to 1.5 mm will be described with reference to FIG.
First, the intermediate component member (12) is obtained as a square frame member by cutting out a central portion (18) of the slide: a rectangle having a length of 70 mm and a width of 20 mm. Thus, a member consisting of a square frame with a width of 3 mm is provided.
Next, the upper component member (11) is formed with a circular hole (16, 17) near each end along the long axis of the slide so that its center comes to the center of the short axis. Cutting gives a member having two holes along the long side of the slide rectangle, near its sides, ie, near the short side of the slide rectangle. The hole is generally circular, for example, the right circular hole is provided so that the hole is spaced 3 mm to the left from the short side of the right side of the slide rectangle, On the other hand, the circular hole on the left side is provided so that the hole is spaced 3 mm to the right from the short left side of the slide rectangle. The center of the circular hole is a hole with a diameter of 9 mm. If the hole on the right side is 7.5 mm on the left side from the short side on the right side of the slide rectangle, the upper and lower sides are the long sides of the slide rectangle. It is 13 mm from the side, while the hole on the left is 7.5 mm to the right from the short left side of the slide rectangle and 13 mm from the upper and lower sides of the long side of the slide rectangle.

Then, the member having two holes (16, 17) for the upper component member is cut out from a glass tube having an inner diameter of the same size as the diameter of the hole of the provided hole. Cylindrical pipe (branch pipe) (14, 15): inner diameter 9 mm, outer diameter 14 mm, pipe thickness 2.5 mm, pipe length 10 mm
Are attached so that the center point of each circle (the axis of the cylinder) coincides with the hole of the member having the two holes for the upper component member. Thus, the cylindrical pipe is integrated with a member having two holes for the upper component member, and it is possible to receive a sample and attach a plug (19, 19 ') having an electrode. Thus, a liquid receiving tank (14, 15) is formed.

The bottom component (13) used to construct this simple zeta potential measuring device can use a slide glass of typical size: length 76 mm x width 26 mm x thickness 0.9-1.5 mm. The intermediate part component (12) formed as described above is laminated on top of each other, and the upper part component (11) formed as described above is superimposed on the product thus obtained. The apparatus of the present invention can be obtained by bonding. Thus, the volume size of the electrophoresis tank cavity (electrophoresis cell) is a flat rectangular parallelepiped hollow box type electrophoresis cell with a cell length of 70 mm x cell width of 20 mm x cell depth of 0.9 to 1.5 mm. It is obtained as a constituent of a zeta potential measuring device for observation.
Examples of the material for the microscope slide glass and the cylindrical pipe material include synthetic quartz glass and natural fused quartz glass. The member used to configure this simple zeta potential measuring device may be a product using high-purity synthetic quartz.

The simple zeta potential measuring device manufactured as described above is a closed electrophoretic cell and is used for measurement using a plug (19) integrated with an electrode. The measuring device may be understood to include a plug member provided with the electrode. The material of the stopper is a fluorine-based resin such as polytetrafluoroethylene, a copolymer of tetrafluoroethylene and other monomers, and specifically, Teflon (registered trademark) by US DuPont. It may be available. As this electrode, you may select and use from what is known in the said field | area, for example, a platinum electrode, a gold electrode, a silver electrode, a nickel electrode, a palladium electrode, a carbon electrode etc. are mentioned. A suitable electrode includes a palladium electrode.

The solid surface in contact with water adsorbs ions from the water or due to the dissociation reaction of the surface itself, the surface is charged, that is, the phenomenon of charge separation occurs at the interface, Ions (counter ions) with the opposite sign to the surface charge are attracted to the surface charge and gather on the surface. At the same time, the ions try to diffuse into the aqueous phase due to the thermal motion of the ions themselves. An electric double layer having a unique structure, that is, a diffusion electric double layer is formed. When a phase in contact with a liquid such as water is moving relatively, the liquid in a layer of thickness from the surface of the contact phase moves with the contact phase due to viscosity. The potential difference between the surface (sliding surface) of this layer and the portion of the liquid sufficiently away from the interface is called the electrokinetic potential, which is generally expressed by the symbol ζ, and is called the zeta potential.
When an electric field is applied to particles with a positive or negative surface charge, the particles electrophores toward the cathode or anode. (a) When the particle size is sufficiently larger than the thickness of the electric double layer, the electrolyte concentration is relatively high, and the particle size is large, Smoluchowski equation (1) holds.

Where, v: electrophoretic velocity, E: electric field strength, u: electrophoretic mobility (electrophoretic velocity per unit electric field), η: liquid viscosity (solution viscosity), ε ₀ : vacuum dielectric Ratio, ε _r : relative dielectric constant of the solution, ζ:
Zeta potential.
On the other hand, when (b) the particle diameter is much smaller than the thickness of the electric double layer, and in the case of very small particles in a dilute aqueous solution, Huckel's equation (2) holds.

In the case between (a) and (b) above, the Henry correction factor is used.
The electrophoresis speed can be measured as follows.
When an appropriate concentration of fine particle suspension (spension) is collected in this simple zeta potential measuring device, that is, in a cell, an electric field is applied and the electrophoretic velocity of the particle is measured along the cell depth (h). ,
A parabolic distribution as shown in FIG. 2 is obtained. H _s expressed by formula (3) from the center axis of the cell to both the top and bottom sides
The velocity at level S ₁ or S _{2 that} is far away is the electrophoretic velocity v of the particles.

Here, K = W / h, W: cell width, and h: cell depth.
The levels S ₁ and S ₂ at h _s are called steady levels. If the cell has a large K,

Becomes a steady level.
By dividing the determined electrophoretic velocity v by the potential gradient (electric field strength) E, the electrophoretic mobility u can be obtained (see equation (1)). Therefore, the ζ potential can be calculated. The potential gradient E is the current i flowing through the cell
From the cell cross-sectional area S, the following equation (5):

Calculated by Here, λ is the specific conductivity of the liquid. The specific conductivity is measured as follows. The electric resistance R of the electrolyte solution is represented by R = L / λS = A / λ. Here, L is the distance between the measurement cell electrodes, and S is the cross-sectional area of the cell. By measuring the electrical resistance of an aqueous solution of known conductivity, the cell constant A = L / S can be determined and λ can be determined.

  In order to measure the zeta potential by electrophoresis, a constant DC electric field is applied to the solution, and the velocity of particles migrating in the electric field is measured. In order to observe the migrating particles under a microscope, you may observe the particle migration directly with an optical microscope or ultramicroscope, but you can attach a video camera to the microscope and use the image processing software It may be used and analyzed. When measuring visually, it can also be devised to facilitate observation by placing a grid on the background. When acquiring an image using a video camera etc., it can be made to cooperate with an image processing system. The image acquisition camera can be appropriately selected from those known in the art, and for example, a CCD camera, a high-vision camera, or the like can be used.

In the zeta potential measurement technique using the simple zeta potential measurement device of the present invention, a system in which data (including electronic data) obtained from an input device such as a CCD camera or a high-vision camera is combined with a personal computer and image processing software. It is usually suitable. The personal computer may be equipped with an external storage device (for example, a hard disk drive, a CD-R, a DVD, an MO drive, etc.) that can store measurement data, and an output device such as a printer or a display. be able to.
The zeta potential measurement is preferably performed conveniently and easily by processing software including analysis software. Through image analysis, the zeta potential can be calculated automatically, the number of particles to be measured can be specified, the measurement can be performed automatically, the trace can be tracked, the particle size can be measured, the aggregated particles and individual particles can be measured. It may also be possible to perform particle measurement.
In automatic measurement, individual particles may be automatically recognized, and the migrating particles may be measured by specifying the time or number. In manual measurement, for example, the start and goal lines are set. Then, when the particles pass on the line, the numerical values may be manually accumulated by clicking the mouse, or the line may be moved on the monitor and data may be collected when the particles move.

In one embodiment of the present invention, images are acquired and processed according to the flowcharts shown in FIGS. 3-5 through a common optical microscope.
FIG. 3 is a flowchart showing an image acquisition process in an image processing apparatus including a light receiving unit arranged on the eyepiece side of a microscope. Proceeding from the start node, it is selected to load a movie file that shows the movement of the observed particles over time (block 51), and the file name given to the loaded movie file is set (Block 52), the maximum number of files to be saved is set (block 53), and the image capture interval is set (block 54). According to the setting, the storage process is performed until the maximum number of files is stored, and the capture interval is set. Is checked and stored for each set capture interval (block 55). If the number of saved files does not reach the set maximum number of saved files, the moving image is advanced by a predetermined image capture interval (block 57). Next, the playback time of the moving image is checked (block 58). If the playback time of the video has not been exceeded, the process returns to before block 55 to capture and save the image being displayed from the video (block 55). In block 56, if the number of saved files has reached the set maximum number of saved files, the process is terminated. Even in block 58, if the playback time of the moving image is exceeded, the process is terminated.

FIG. 4 is a flowchart showing a process for binarizing the acquired image data. Proceeding from the start node, the first choice is to load the image (
Block 71), the color of the particles in the image is set (block 72), and the next functioning block 73 determines whether the color of one pixel of the image is close to white in terms of RGB average values. If the color of the pixel is close to white in the RGB average value, the color of the pixel is set to white (block 74). If the pixel color is not close to white in the RGB average value, the pixel color is changed to a particle color (block 75). Program flow proceeds to 76 and moves to the next pixel. Thus, it is determined whether or not all the pixels have been determined. If all the pixels have been determined, the process is terminated. On the other hand, if all the pixels have not been determined yet, the process returns to block 73 and the processes after the determination process of 73 are repeated.

FIG. 5 is a flowchart showing a process for synthesizing images. Proceeding from the start node, an arbitrary number of two or more images are loaded (block 91).
Proceeding to block 91, the color of pixels at the same position in a plurality of images is averaged, and a process of drawing a composite image is executed (block 92). In the next functioning block 93, it is determined whether or not all the pixels have been processed. If all the pixels have been processed, the process is terminated. If all the pixels have not been processed, the process returns to before block 92 to repeat the processes after 92.

The apparatus of the present invention may be configured as a closed electrophoretic cell using members having the same specifications as the microscope preparation. The measurement system of the present invention is a closed electrophoretic cell prepared by processing a member of the same or equivalent standard as a microscope slide glass, and if the apparatus of the present invention that fits the sample receiving tank of the cell is used, For particles of a size of around micron that can be observed with a microscope, the zeta potential can be measured with an accuracy comparable to that of a commercially available zeta electrometer. Currently, commercially available zeta electrometers are expensive, ranging from 5 to 15 million yen, and are rarely introduced at industrial technology centers in each prefecture, so it is not possible to measure zeta potential easily. . On the other hand, the device of the present invention is a very simple device composed of a combination of a glass cell, a Teflon (registered trademark) stopper and a palladium electrode, and is very inexpensive.
Commercially available zeta electrometers are very expensive, and other methods require you to make your own measurement system. In addition, since the self-made device is an open system, it is easily affected by disturbances such as convection. The apparatus and method for measuring the zeta potential of the fine particles of the present invention simply and inexpensively makes it possible to perform measurement at a very low cost compared to a commercially available zeta potentiometer, and also compared with the classical method. However, it is possible to easily and accurately measure the zeta potential using a common microscope that is widely used.

With the technology of the present invention, the dispersion and adsorption properties of paints, inks, etc. are investigated, the relationship between surfactants and stains is examined to evaluate the cleaning ability, and the dyeability and adsorption properties in the fields of paper, pulp, fibers, etc. It can be used for the study of biological properties such as the relationship between biological cells and micelles, etc. Useful. In the apparatus of the present invention and the zeta potential measurement method using the apparatus, it is possible to measure while visually observing the migration of particles, for example, a particle size of 0.02 μm to 500 μm, more preferably 0.1 μm to 100 μm. The particle size can be measured.
With the technology of the present invention, the zeta potential can be easily measured, and in the fields of medicine, cosmetics, fragrances, foods, and even nanobio, emulsion dispersion / aggregation control, protein functionality, liposome / vesicle dispersion / aggregation control, It can be used to analyze the functionality of surfactants and micelles. Furthermore, in the semiconductor field, it can be used to elucidate the adhesion mechanism of foreign matter on the surface of silicon wafers, and to study the interaction between abrasives and additives and the wafer surface. In the ceramics and color materials industry, silica, alumina, titanium oxide For surface modification of ceramics and inorganic sols such as, dispersion and aggregation control, dispersion and aggregation control of pigments such as carbon black and organic pigments, slurry samples, color filters, adsorption research for floating minerals, etc. Available. In the field of polymer and chemical industries, dispersion and aggregation of emulsions such as paints and adhesives, surface modification of latex, research on functionality of electrolyte polymers such as polystyrene sulfonate and polycarboxylic acid, functional nanoparticles It can be used for the control of paper making processes such as paper and pulp, and the study of pulp additives.

The present invention will be described in detail with reference to the following examples, which are provided merely for the purpose of illustrating the present invention and for reference to specific embodiments thereof. These exemplifications are for explaining specific specific embodiments of the present invention, but are not intended to limit or limit the scope of the invention disclosed in the present application. In the present invention, it should be understood that various embodiments based on the idea of the present specification are possible.
All examples were performed or can be performed using standard techniques, except as otherwise described in detail, and are well known and routine to those skilled in the art. .

[Construction of simple zeta potential measurement device]
Size: 76 mm long x 26 mm wide x 1.0 mm thick slide glass and size: 76 mm long
The electrophoresis cell which comprises the simple zeta potential measuring device of this invention is produced using the slide glass of * width 26mm * thickness 1.5mm. Reference can be made to FIG.
First, the intermediate component member (12) is produced using a synthetic quartz slide glass of size: length 76 mm × width 26 mm × thickness 1.0 mm. Central part (18) of the slide: A rectangular frame-shaped member is obtained by cutting out a rectangle having a length of 70 mm and a width of 20 mm. Thus, a member consisting of a square frame with a width of 3 mm is provided.
Next, the upper component member (11) is prepared using a synthetic quartz slide glass of size: length 76 mm × width 26 mm × thickness 1.5 mm. Cut out a 9 mm diameter circular hole (16, 17) centered at the center of the shaft along the minor axis, 8 mm inside from each end of the shaft along the major axis of the slide This gives a member with two holes along the long side of the slide rectangle, near its sides, i.e. near the short side of the slide rectangle. The hole is provided so that the hole is spaced 3 mm to the left from the short side on the right side of the slide rectangle, while the left circular hole is from the short side on the left side of the slide rectangle. , The holes are provided 3 mm apart on the right side. The center of the circular hole is drilled with a 9 mm diameter hole, so in the right hole, the upper and lower sides, which are the long sides of the slide rectangle, from the short side of the right side of the slide rectangle to the left side of 7.5 mm. 13 mm from the left side of the slide rectangle, and 7.5 mm to the right side of the left side of the slide rectangle, and 13 mm from the upper and lower sides of the long side of the slide rectangle. Next, a cylindrical synthetic quartz pipe having an inner diameter of 9 mm, an outer diameter of 14 mm, a pipe thickness of 2.5 mm, and a pipe length of 10 mm is placed at the hole, and the center point of each circle (cylinder) Are attached so that they coincide with each other to form a branch pipe, that is, a sample receiving tank (electrode plug receiving port).
Two sample receiving tanks are installed on an upper component member made of a slide glass. They can be used as the anode side and the cathode side, respectively.

Next, a synthetic quartz slide glass having a size: length 76 mm × width 26 mm × thickness 1.5 mm is used as the bottom component member (13), and the intermediate component member formed as described above is used thereon. (12) are stacked and bonded, and the upper component member (11) formed as described above is stacked and bonded to the electrophoresis cavity and the sample receiving tank (electrode) connected thereto. An electrophoretic cell having a plug receptacle is obtained. Thus, the volume size of the electrophoresis tank cavity (electrophoresis cell) is a flat rectangular parallelepiped hollow box type electrophoresis cell with a cell length of 70 mm x cell width of 20 mm x cell depth of 1.0 mm. Obtained as a constituent of the zeta potential measuring device.
This simple zeta potential measuring device is configured using two Teflon (registered trademark) plugs equipped with a palladium electrode. The simple zeta potential measuring device manufactured as described above is a closed electrophoretic cell and is used for measurement using a plug (19) integrated with an electrode.

By utilizing the technology of the present invention, it is possible to measure the zeta potential at low cost, easily and accurately, and in a wide range of fields such as materials, environment, food, medicine, and electronics, Since the zeta potential, which is the interface potential of fine particles in a solution, can be measured, it can be applied to research and analysis of colloids and interfacial chemistry, dispersion and aggregation control of emulsions, water quality management, environmental improvement, quality control, and so on. The apparatus and method of the present invention are used in the fields of production of paints, inks, etc., the field of washing evaluation and surfactant production, the field of paper, pulp, textile industry, etc. involving dyeing and adsorption, water and sewage, washing water It is used in various industries such as water quality management, flotation, biotechnology industry and food industry.
It will be apparent that the invention may be practiced otherwise than as particularly described in the foregoing description and examples. Many modifications and variations of the present invention are possible in light of the above teachings, and thus are within the scope of the claims appended hereto.

1 shows a simple zeta potential measuring device of the present invention, that is, an electrophoresis cell and an electrode plug. A: Appearance of the cell as seen from above. A region exclusively used for zeta potential measurement is shown as an effective part. B: Appearance of the cell as viewed from below. A region exclusively used for zeta potential measurement is shown as an effective part. C: Appearance of the cell as viewed from the side along the long axis, with the electrode plug (19) installed in the sample receiving tank. The arrow in the middle of the cell indicates the direction of observation with a microscope. D: Appearance of the cell viewed from the side along the long axis and appearance of the two electrode plugs viewed from the lateral direction are shown so that the relationship between the electrode plug and the sample receiving tank of the cell can be grasped. It is what is shown. E: It is the external appearance which looked at this cell from the side surface along a short axis. Above that, the external appearance of the electrode plug viewed from the lateral direction is shown, so that the relationship between the electrode plug and the sample receiving tank of the cell can be grasped. A is the appearance of the electrophoretic cell viewed from above, and b is the external appearance of the electrophoretic cell viewed from below. At the same time, the bottom component (13) is also displayed. 11 between a and b indicates an upper component of the cell, and 12 indicates an intermediate component of the cell. The relationship between the depth of the electrophoretic measurement cell of the simple zeta potential measuring device and the electrophoretic velocity of the measurement target particle is shown. It is the flowchart which showed the data processing (moving image processing) for acquiring and analyzing the image (a moving image is included) obtained with a CCD camera through a microscope, for example. It is a flowchart which shows the flow of the process for binarizing the acquired image data and performing data processing. It is a flowchart which processes image data and performs image composition processing, and processes it conveniently for zeta potential measurement.

Claims (3)

A substantially cylindrical plug member having an electrode for applying a DC electric field, a cylindrical opening tank portion that detachably receives the plug member, and a flat rectangular parallelepiped shape that communicates with the opening of the opening tank section It is composed of a rectangular parallelepiped flat-plate glass electrophoresis cell having an electrophoresis tank cavity at the center and integrated with the opening tank part, and the opening tank part is the electrophoresis tank cavity Two zeta potential measuring devices for microscopic observation, characterized in that two are arranged on both side portions of the microscopic device. Using a synthetic quartz slide glass, by cutting out a rectangle at the center of the slide glass, an intermediate component member that is a member made of a square frame is produced, and then using a synthetic quartz slide glass, Cut out two circular holes centered at the center of the shaft along the short axis at the inside of each end of the shaft along the long axis of the slide, and A member having two holes in the vicinity is obtained, and a cylindrical synthetic quartz pipe is attached to the hole so that the center points of the circles coincide with each other. There is an upper part forming member having an electrode plug receiving port, and then using a synthetic quartz slide glass as a bottom part member, on which the intermediate part member made above is stacked and bonded, In addition, Electrophoresis cell configured by stacking and laminating the upper side constituent members prepared as described above, an electrophoresis cell having two sample plug receiving ports connected to the sample cavity, and fluorine equipped with a palladium electrode The zeta potential measuring device for microscopic observation according to claim 1, comprising two plugs made of a resin. A zeta potential measurement method, wherein the particles are observed with a microscope using the zeta potential measurement device for microscopic observation according to claim 1.

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