TWI807329B - Measuring method and measuring system for microbubble dispersion liquid - Google Patents

Abstract

Provided are a measuring method and a measuring system of a microbubble dispersion liquid that are capable of properly measuring the characteristics of the microbubble dispersion liquid while distinguishing between fine particles in the dispersion liquid and differentiating them into microbubbles and solid particles. The measuring system includes a microcapillary to hold the liquid under test, a laser device that irradiates the liquid under test inside the microcapillary with laser light, a variable magnetic field applying device that applies a time-varying magnetic field to the liquid under test within the irradiation area with laser light, a digital microscope that detects scattered light generated from fine particles contained in the liquid under test by irradiation with laser light, and a measurement device that measures the characteristics of the liquid under test based on the brightness of scattered light detected by the digital microscope.

Description

Measuring method and measuring system of microbubble dispersion liquid

The present invention relates to a measurement method and a measurement system of microbubble dispersion liquid. More specifically, the present invention relates to a measurement method and a measurement system for measuring the properties of a microbubble dispersion liquid containing microbubbles.

Research and discuss the application of microbubble dispersion containing microbubbles in various industrial fields. Among the microbubbles, these microbubbles with nanoscale particle size (hereinafter referred to as "nanoscale diameter bubbles") have the characteristic of being able to stay in water for a long time (for example, several years), because their movement in the dispersion is mainly Brownian motion. For this reason, microbubble dispersions having nanometer diameter bubbles dispersed have been extensively studied. See eg Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2019-103958).

The presence or absence of microbubbles in a microbubble dispersion can be determined relatively easily by whether the liquid is cloudy or not. In contrast, since the particle size of nanoscale bubbles is approximately the same as or smaller than the wavelength of light, the presence or absence of nanoscale bubbles in a microbubble dispersion cannot be confirmed with the naked eye.

In addition, techniques such as dynamic light scattering and particle trajectory tracking are known to optically measure the concentration and particle size distribution of microparticles that perform Brownian motion in a dispersion containing the aforementioned nanoscale microparticles. In the dynamic light scattering method and the particle trajectory tracking method, the concentration and particle size distribution of fine particles are measured, the liquid dispersed through the fine particles is irradiated with laser light, and the scattered light of the fine particles is tracked.

[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2019-103958.

[technical problem]

In some cases, the microbubble dispersion contains not only nanoscale diameter bubbles but also impurities such as nanoscale microsolid particles. However, although the methods commonly used to measure particles in a liquid containing dispersed particles can identify nanoscale particles in the liquid, this method cannot distinguish nanoscale diameter bubbles from solid particles.

An object of the present invention is to provide a measurement method and a measurement system, which can distinguish the microparticles in the dispersion liquid, and distinguish them into microbubbles and solid particles, so as to accurately measure the characteristics of a microbubble dispersion liquid. [problem solution]

(1) A method for measuring a microbubble dispersion liquid according to the present invention, which is a method for measuring the properties of a liquid to be tested and the liquid to be tested is a microbubble dispersion liquid, wherein the method includes the following steps: irradiating the liquid to be tested contained in a container with an illumination light, applying a time-varying magnetic field to the liquid to be tested in the irradiation area of the illumination light, using a light detection device to detect scattered light generated by the plurality of microparticles contained in the liquid to be tested by the illumination light; The measured brightness of the scattered light distinguishes the microparticles and differentiates them into microbubbles and solid particles.

(2) In this case, preferably, the liquid to be tested contains microbubbles with a particle size ranging from 2 nm to 2000 nm.

(3) In this case, it is preferable to distinguish the fine particles into solid particles and microbubbles by comparing an image brightness of the fine particles obtained by the light detection means with a predetermined threshold.

(4) In this case, preferably in the step of detecting the scattered light, the scattered light measured by the photodetection device is used to obtain an image of the Brownian motion trajectory of the microparticles before and after applying the variable magnetic field, wherein in the image obtained by the photodetection device, the microparticles are identified as solid particles and microbubbles according to whether the brightness increases when the variable magnetic field is applied to the liquid to be tested.

(5) In this case, preferably in the image obtained by the photodetection device, when the variable magnetic field is applied to the liquid to be tested, the microparticles whose brightness increases are identified as solid particles, the microparticles that will disappear are identified as charged microbubbles, and the microparticles whose brightness does not increase are identified as uncharged microbubbles.

(6) In this case, preferably, the measurement method further includes measuring solid particles, wherein the concentration or particle size distribution of solid particles contained in the liquid to be measured is calculated based on an image obtained by the light detection device.

(7) In this case, preferably, the measuring method further includes measuring uncharged microbubbles, wherein the concentration or particle size distribution of uncharged microbubbles contained in the liquid to be tested is calculated based on an image obtained by the photodetection device.

(8) In this case, preferably, the measurement method further includes measuring charged microbubbles, wherein the following two are obtained in the step of detecting scattered light: a pre-application image of the Brownian motion trajectory of the microparticles before the variable magnetic field is applied to the liquid, and an application process image of the Brownian motion trajectories of the microparticles when the variable magnetic field is applied to the liquid, and at least any one of the concentration and particle size distribution of the charged microbubbles contained in the liquid to be measured is calculated based on the images.

(9) In this case, preferably, the measurement method further includes performing a first screening of the liquid to be tested, wherein the liquid to be tested has passed through a positively charged filter before the liquid to be tested is contained in the containing device.

(10) In this case, it is preferable to calculate the particle size of the solid particle by using a light detection device to obtain an image of the particle according to the change degree of the brightness of the scattered light when a variable magnetic field is applied to the liquid.

(11) In this case, preferably, the measurement method further includes applying an electric field to the liquid to be tested in the illumination area of the illumination light, and in the step of detecting scattered light, obtaining an application process image of the electrophoretic trajectory of the microparticles when the electric field is applied to the liquid to be tested, and measuring the properties of solid particles contained in the liquid to be tested according to the application process image.

(12) In this case, preferably, the measurement method further includes performing a second screening of the liquid to be tested, wherein before applying a variable magnetic field to the liquid to be tested, a static magnetic field is applied to the liquid, thereby at least part of the solid particles are moved out of the irradiation area.

(13) In this case, preferably the measuring method further includes measuring the amount of paramagnetic substance, wherein the amount of paramagnetic solid particles is measured, and the solid particles are collected by applying the static magnetic field to the liquid to be tested in the second screening step.

(14) In this case, preferably the light source of the illumination light is a laser device capable of switching the wavelength of the laser light by using two or more wavelength values within the defined range of 300 nm to 700 nm.

(15) A measurement system for measuring a microbubble dispersion liquid according to the present invention, which is a system for measuring the characteristics of a liquid to be tested and the liquid to be tested is a microbubble dispersion liquid, wherein the system includes: a container, which holds a liquid to be tested; a light source, which illuminates the liquid to be tested contained in the container; The scattered light produced by the microparticles contained in the liquid to be tested; and a measuring device, which measures the characteristics of the liquid to be tested, and distinguishes the microparticles into microbubbles and solid particles according to the brightness of the scattered light measured by the light detection device. [Beneficial effects of the present invention]

(1) The method for measuring microbubble dispersion liquid according to the present invention includes the following steps: irradiating the liquid to be tested contained in a container with illuminating light; applying a time-varying magnetic field to the liquid to be tested in the area irradiated by the illuminating light; and using a light detection device to emit illuminating light to detect the scattered light generated by the microparticles contained in the liquid to be tested. As mentioned above, the liquid to be tested (which is a microbubble dispersion) may contain solid particles and microbubbles. If a variable magnetic field is applied to such a liquid to be tested, the solid particle with biased magnetic permeability can withstand a larger rotational or translational moment of force under a variable magnetic field than a spherical particle (with the center of gravity as its center in terms of magnetic permeability), so that the former will rotate around its axis. In contrast, microbubbles (spherical particles with a center of gravity at their center in terms of magnetic permeability) experience smaller rotational or translational moments under a variable magnetic field than solid particles. In addition, compared with solid particles, the microbubbles, which have almost no magnetic permeability, have a very small weight, and are subject to great viscous resistance from the surrounding medium, so the microbubbles hardly rotate around their axes. When the liquid to be measured is irradiated with illumination light and applied with a variable magnetic field, the scattered light brightness of the solid particles rotating around the axis increases more than that of the microbubbles not rotating around the axis. Therefore, the measurement method of the present invention distinguishes microbubbles and solid particles in the liquid to be measured according to the brightness of scattered light measured by the light detection device. Accordingly, the measuring method of the present invention can measure the characteristics of the liquid to be tested with high accuracy, and at the same time distinguish the microparticles contained in the liquid to be tested and differentiate them into microbubbles and solid particles.

(2) The measurement method of the present invention measures the liquid to be tested, which contains microbubbles with a particle size ranging from 2 nm to 2000 nm. As mentioned above, known measurement methods cannot distinguish nanometer-sized diameter bubbles from solid particles of similar size. In contrast, even if the microbubble dispersion contains solid particles with a similar particle size to nano-sized bubbles, the measurement method of the present invention can measure the properties of the liquid to be tested with high accuracy while distinguishing the solid particles and nano-sized bubbles.

(3) The measurement method of the present invention distinguishes the microparticles into solid particles and microbubbles by comparing the brightness of the microparticle image obtained by the photodetection device with a predetermined threshold. In this way, the microparticles can be distinguished into solid particles and microbubbles in a simple manner.

(4) In the measurement method of the present invention, in the step of detecting scattered light, the Brownian motion trajectory image of the microparticle is obtained with the photodetection device before and after applying a variable magnetic field to the liquid to be tested, and in the image obtained with the photodetection device, the microparticle is classified into solid particles and microbubbles according to whether the brightness increases when the variable magnetic field is applied to the liquid. Therefore, the method can distinguish the microparticles as solid particles or microbubbles when tracking the movement of the microparticles due to Brownian motion.

(5) The microparticles contained in the microbubble dispersion liquid are divided into microsolid particles and microbubbles, and the microbubbles are divided into positively or negatively charged microbubbles and uncharged microbubbles with little or no charge. As mentioned above, if a variable magnetic field is applied to the liquid to be tested, the solid particles with partial magnetic properties rotate around the axis, the charged microbubbles disappear, and the uncharged microbubbles do not rotate around the axis. Accordingly, in the measurement method of the present invention, particles whose brightness increases when the variable magnetic field is applied are identified as solid particles, particles that disappear when the variable magnetic field is applied to the liquid are identified as charged microbubbles, and particles that do not increase in brightness when the variable magnetic field is applied to the liquid are identified as uncharged microbubbles. Therefore, the measuring method of the present invention can measure the properties of the liquid to be tested with high accuracy and distinguish the microparticles contained in the liquid to be tested into solid particles, charged microbubbles and uncharged microbubbles.

(6) The measurement method of the present invention includes the following steps: measuring solid particles, wherein at least one of the solid particle concentration and particle size distribution contained in the liquid to be measured is calculated based on the image obtained by the light detection device. Therefore, the measurement method of the present invention can measure the concentration and/or particle size distribution of solid particles with high accuracy while distinguishing the solid particles and microbubbles.

(7) The measurement method of the present invention includes the following steps: measuring uncharged microbubbles, wherein at least any one of the concentration and particle size distribution of the uncharged microbubbles contained in the liquid to be tested is calculated based on the image obtained by the light detection device. Therefore, the measurement method of the present invention can measure the concentration and/or particle size distribution of the uncharged microbubbles with high accuracy while distinguishing the uncharged microbubbles, solid particles and charged microbubbles.

(8) In the measurement method of the present invention, the following two are obtained in the step of detecting scattered light: a pre-application image of the Brownian motion trajectory of the microparticle before the variable magnetic field is applied to the liquid, and an application process image of the Brownian motion trajectory of the microparticle when the variable magnetic field is applied to the liquid. The measurement method of the present invention also includes the step of measuring charged microbubbles, wherein at least any one of the concentration and particle size distribution of charged microbubbles contained in the liquid to be tested is calculated based on the images. Therefore, the measurement method of the present invention can measure the concentration and/or particle size distribution of the charged microbubbles with high accuracy and distinguish the charged microbubbles, solid particles and uncharged microbubbles.

(9) Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2019-103958) confirms that the microparticles in the microbubble dispersion liquid, especially the positively charged microbubbles, have the effect of promoting plant growth. In contrast, in the measuring method of the present invention, the liquid to be tested is contained before a containing device, and the liquid to be tested has passed through a positively charged filter. As a result, since the negatively charged microbubbles contained in the liquid to be tested have been removed, the measuring method of the present invention can measure the concentration and/or particle size distribution of the positively charged microbubbles with high accuracy.

(10) When a variable magnetic field is applied to the liquid to be tested, the number of rotations of the solid particles will be related to the change in the brightness of the scattered light. When a variable magnetic field is applied to the liquid, the number of rotations of the solid particles is also related to the size of the solid particles. Therefore, the present invention uses the above-mentioned correlation between the intensity of scattered light and the change degree of the particle size of the solid particle and calculates the particle size of the solid particle according to the change degree of the light intensity of the scattered light in the microparticle image obtained by the photodetection device. Therefore, the measurement method of the present invention can simply measure the particle diameter of solid particles.

(11) In the measurement method of the present invention, an electric field is applied to the liquid to be tested in the illuminated area to obtain an image of the electrophoretic trajectory of microparticles, and the properties of the solid particles contained in the liquid to be tested are measured. Therefore, the measurement method of the present invention can measure the electrical properties of solid particles.

(12) The measurement method of the present invention removes at least a part of the solid particles from the irradiation area by applying a static magnetic field before applying a variable magnetic field to the liquid. This makes it possible for the paramagnetic solid particles among the solid particles contained in the liquid to be measured to move out of the irradiation area, further improving the measurement accuracy.

(13) As mentioned above, the measurement method of the present invention moves paramagnetic solid particles out of the irradiation area by applying a static magnetic field, and collects the particles to measure the amount of paramagnetic solid particles. This enables the amount of paramagnetic solid particles contained in the liquid to be tested to be measured in a simple manner.

(14) When a variable magnetic field is applied to the liquid to be tested, the number of rotations of the solid particles depends on the physical properties and shape of the solid particles and the viscosity of the medium. The brightness of the scattered light depends on the number of rotations of the solid particles and the wavelength of the irradiated light. Therefore, if the wavelength of the irradiated light is fixed, the brightness of the scattered light may no longer increase or be saturated. In contrast, the present invention uses a laser device that can switch the wavelength of laser light by using a plurality of wavelength values defined within the range of 300 nm to 700 nm as a light source for irradiating light. Therefore, if the brightness of the scattered light cannot be measured because the brightness cannot be increased or is saturated, the wavelength of the laser light can be switched accordingly so that the brightness of the scattered light can be properly measured.

(15) A measuring system for the microbubble dispersion liquid of the present invention, which includes: a container for containing a liquid to be tested; a light source for illuminating the liquid for testing contained in the container for illumination; a variable magnetic field applying device for applying a time-varying magnetic field to the liquid for testing in the illuminated area; The brightness of the scattered light measured by the detection device distinguishes the microparticles into microbubbles and solid particles. Therefore, based on the same reason as the invention included in this section (1), the measurement system can measure the properties of the liquid to be tested with high accuracy, and at the same time distinguish the microparticles contained in the liquid to be tested and distinguish them into microbubbles and solid particles.

First specific embodiment

The configuration of a measurement system 1 will be described in detail below with reference to the drawings, wherein the method for measuring microbubble dispersion liquid according to the first embodiment is applied to the measurement system 1 .

The measurement system 1 is used to measure the characteristics of a liquid to be tested, which is a microbubble dispersion liquid in a fluid medium, in which there are dispersed plural microbubbles. The properties of the microbubbles such as particle size distribution and microbubble number concentration dispersed in the liquid to be tested. As described below, the liquid to be tested is a nanobubble dispersion, wherein microbubbles and solid particles with a particle size ranging from 2 nm to 2000 nm are dispersed in the fluid medium. Hereinafter, microbubbles and solid particles are also collectively referred to as fine particles. In addition, the fluid medium used is pure water or sodium chloride (NaCl) solution, but the fluid medium used in the present invention is not limited thereto. Moreover, in the measurement system 1 described below, when the fluid medium used is pure water without inorganic ions, the particle size of the microparticles can be calculated with high accuracy, but the fluid medium in the present invention is not limited to pure water. The fluid medium used can be any fluid as long as the fine air bubbles can be dispersed in the fluid medium.

The measurement system 1 includes: a microcapillary 2, which is used as a containing device to hold a liquid to be tested; a laser device 3, which is used as a light source for irradiating the liquid to be tested in the microcapillary 2 with a laser light L as an illumination light; a variable magnetic field applying device 5, which uses the laser light L to apply a variable magnetic field to the liquid to be tested in an irradiation area A; a digital microscope 6, which is used as a photodetection device. Scattered light S; a measuring device 7, which is a computer for measuring the characteristics of the liquid to be tested according to the image data obtained by the digital microscope 6; and a filter device 8, which filters out impurities and other substances contained in the liquid to be tested.

As described below, the microcapillary 2 is provided with a micron-scale conduit as shown in FIG. 1 as a containment device for containing the liquid to be tested, but the containment device of the present invention is not limited thereto. As a containment device, any device capable of containing the liquid to be tested by capillary phenomenon like the microcapillary 2 is acceptable. For example, the following devices can be used: a rail plate 21 on which grooves (groove) of micron-scale width are formed (see FIG. 2A ); a pair of glass plates 22 stacked with a micron-scale pitch (see FIG. 2B ); and polymer parallel strings 23 arranged at a micron-scale pitch (see FIG. 2C ).

The laser device 3 generates, for example, the laser light L with a wavelength ranging from 300 nm to 700 nm, and irradiates the irradiation area A defined inside the capillary of the microcapillary 2 with the laser light L. The laser device 3 preferably used can switch the wavelength of the laser light L by using more than two wavelength values defined within the range of 300 nm to 700 nm. As described below, the laser device 3 is used as a light source, but the light source in the present invention is not limited thereto. For example, light emitting diodes can be used as light sources.

The variable magnetic field applying device 5 includes a coil pad 51 held and operated by an operator and a main body 52. The main body 52 generates a variable magnetic field from the coil pad 51 at a predetermined setting period. In the variable magnetic field applying device 5 here, the period and the magnetic flux density of the variable magnetic field can be set within a predetermined range. Therefore, the variable magnetic field applying device 5 can also generate a static magnetic field by setting the period of the variable magnetic field to be infinite. As described below, both the variable magnetic field and the static magnetic field are selectively applied to the irradiation area A with the laser light L in the microcapillary 2 by using the variable magnetic field applying device 5 , but the present invention is not limited thereto. Specifically, as a means for generating the static magnetic field, a magnet prepared in advance and independent of the variable magnetic field applying device 5 can be used.

In addition, as described below, as the variable magnetic field applying device 5 for generating the variable magnetic field, MRS1000 (The Magstim Company Ltd., U.K.) is used but the present invention is not limited thereto. The variable magnetic field is applied within the microcapillary 2 by moving the magnet closer to or farther away from the irradiation area A using an actuator (not shown).

Furthermore, FIG. 1 shows a case where a single-coil type coil pad 51 including one circular coil is used, but the present invention is not limited thereto. In addition to this coil pad 51, as shown in FIG. 3, a double coil type coil pad 51A including two circular coils 511, 512 is used. The coils 511 and 512 are slightly inclined. As a result, compared with the single-coil coil pad 51 , the double-coil coil pad 51A can better improve the convergence of magnetic flux, so that the magnetic flux density in the irradiation area A can be selectively concentrated.

The digital microscope 6 includes: an optical system (not shown) is located in the light path of the scattered light S, the scattered light S is produced by the microparticles contained in the liquid to be tested in the irradiation area A of the microcapillary 2 with the laser light L, wherein the scattered light S incident (incident) is received by the optical system; and an image device (not shown), which converts the brightness of the scattered light S into electronic signals to generate image data. An example of the imaging device is a CCD or a CMOS image sensor. The image data obtained by the digital microscope 6 is transmitted to the measuring device 7 .

The measuring device 7 is a computer with a program installed, and the program performs numerical processing on the microparticle image data to measure the properties of the liquid to be tested (such as particle size distribution and particle number concentration of the microparticles, such as microbubbles and solid particles dispersed in the liquid to be tested). Specific steps for measuring the properties of the liquid to be tested with the measuring device 7 will be described later with reference to the drawings including FIGS. 5 and 6 .

The filter device 8 includes a filter body, and the filter body is provided with a plurality of filter holes with a predetermined inner diameter. The inner diameter of the filter hole of the filter main body is adjusted so that the microparticles in the liquid to be tested can pass through, thereby capturing solid particles with larger particle diameters in the liquid to be tested. Therefore, the liquid to be tested is allowed to pass through the filter body so that the solid particles dispersed in the liquid to be tested with a particle diameter larger than the inner diameter of the filter hole are removed in advance. As described below, the filter body used is positively charged so that the filter body can also collect negatively charged microbubbles among the microbubbles dispersed in the liquid to be tested, but the present invention is not limited thereto. The filter body used may be neutral or negatively charged.

FIG. 4 is a flow chart of the specific steps of the measurement method for measuring the properties of the liquid to be measured by the above-mentioned measurement system 1 .

First, in S1, an operator passes a liquid to be tested through a positively charged filter body, wherein the liquid to be tested is a pre-prepared microbubble dispersion. In this step, the solid particles with larger particle size and the negatively charged microbubbles among the microparticles dispersed in the liquid to be tested are removed. The microbubble dispersion used as the test liquid can be prepared in advance, or the test liquid can be produced by a microbubble generator (not shown).

Then, in S2, the operator makes a microcapillary 2 contain the liquid to be tested, which passes through the inside of the filter body by capillary phenomenon.

Then, in S3, the operator operates a variable magnetic field applying device 5 to generate a static magnetic field from a coil pad 51 by setting the variable magnetic field cycle to be infinite, and makes the coil pad 51 close to the microcapillary 2 to apply the static magnetic field to the liquid to be tested in the microcapillary 2. In addition, in S3, the coil pad 51 is scanned along the extending direction of the microcapillary 2, so that a part of solid particles (especially paramagnetic solid particles) in the liquid to be tested in the microcapillary 2 move out of the irradiation area A of a laser light L. As described here, the variable magnetic field applying device 5 is used to apply the static magnetic field to the liquid to be tested, but the method of applying the static magnetic field is not limited thereto. For example, a magnet prepared separately from the variable magnetic field applying device 5 can be used to apply the static magnetic field to a liquid to be tested. The number of solid particles collected by applying the static magnetic field to the liquid to be tested as described above can be independently measured by known methods.

Then, in S4, the operator starts emitting the laser light L with the laser device 3 . More specifically, the operator operates the laser device 3 to generate the laser light L, and irradiates the predetermined irradiation area A in the microcapillary 2 with the laser light L.

Then, in S5, the operator starts to take a dynamic image of the irradiation area A with a digital microscope 6 .

After a predetermined time elapses from the dynamic image that the operator starts to shoot in S5, then in S6, the operator uses the variable magnetic field applying device 5 to apply a variable magnetic field to the liquid to be tested for a predetermined time. The changing period of the magnetic field is, for example, 0.1 second, and the magnetic flux density of the variable magnetic field at the coil pad 51 is 0.5-2.0 T, but the present invention is not limited thereto.

Then, in S7 , the operator uses the variable magnetic field applying device 5 to finish applying the variable magnetic field, and then uses the digital microscope 6 to take a moving image, and the laser device 3 emits the laser light L. The above steps provide a moving image of many microparticles dispersed in the object to be measured due to Brownian motion. As described below, the digital microscope 6 captures dynamic images before and after applying the variable magnetic field, but the present invention is not limited thereto. For example, a method of taking multiple still images can be used, wherein the Brownian motion trajectory of the microparticles dispersed in the liquid to be tested can be tracked.

Then, in S8, the operator operates a measuring device 7 to calculate the concentration and particle size distribution of the microparticles based on the dynamic image data of the microparticles obtained by the digital microscope 6 .

Fig. 5 is a flow chart showing the steps of calculating the concentration and particle size distribution of fine particles using the measuring device 7. The liquid to be tested contains positively charged microbubbles, uncharged microbubbles and nanoscale particles including solid particles dispersed therein, but such nanoscale particles cannot be identified by common methods such as dynamic light scattering method and particle trajectory tracking method. In contrast, the measuring device 7 can distinguish positively charged microbubbles, uncharged microbubbles and solid particles to calculate their respective concentrations and particle size distributions, which will be described in detail below. Hereinafter, before describing the specific steps of the flow chart in FIG. 5 , the measurement method using the measurement device 7 will be briefly described with reference to FIG. 6 .

FIG. 6 is an example diagram of microparticle images obtained by using the digital microscope 6 to detect scattered laser light. Figure 6 provides an enlarged view of some microparticles for reference.

As shown in FIG. 6, the liquid to be tested includes uncharged microbubbles 4a, charged microbubbles 4b and solid particles 4c, 4d dispersed therein. Moreover, the solid particles dispersed in the liquid to be tested have various shapes, including solid particles 4c which are relatively close to a true spherical shape, and solid particles 4d which are distorted shapes which are far from a true spherical shape. However, these microparticles 4a-4d have particle diameters in the nanometer scale, which are equal to or smaller than the wavelength of laser light, so that these microparticles cannot be identified by detecting images obtained from scattered light. However, as shown in FIG. 6 , when the variable magnetic field applying device 5 is used to apply a predetermined periodic time-varying magnetic field to the liquid to be tested, the microparticles behave differently.

More specifically, the solid particles 4c, 4d with deflection magnetism are subjected to rotational or translational forces under a variable magnetic field to rotate around their axes. In this case, the solid particle 4c having a relatively close true spherical shape is considered to have less viscous resistance than the solid particle 4d having a distorted shape, and therefore, the solid particle 4c rotates faster than the distorted solid particle 4d. Therefore, if a variable magnetic field is applied to the solid particles while emitting laser light, the brightness of the scattered light of the solid particles 4c, 4d increases more than before the variable magnetic field is applied. Also at this time, since the solid particle 4d rotates faster than the solid particle 4c, the brightness of the solid particle 4d increases more than that of the solid particle 4c. In addition, it is considered that the brightness of the solid particles 4c, 4d increases more as the particle size increases.

For reference, the following formula (1) represents the motion equation of a sphere, where the magnetic moment of a sphere with mass M (kg) and radius r (m) in a medium with a viscosity coefficient of μ (N•s/m ² ) is m (wb•m), and a time-varying magnetic field H (A/m) with a frequency of ω _o (rad/s) is applied to the medium. In formula (1), t (s) is the time, θ (rad) is the angle defined by the magnetic moment m and the magnetic field H. (1) [Formula 1]

In contrast, compared to solid particles, the uncharged microbubbles 4a have almost no magnetic permeability and small weight, which cause very large viscous resistance to the surrounding medium, so that they hardly rotate even when a variable magnetic field is applied to the uncharged microbubbles 4a. Therefore, even if a variable magnetic field is applied to the microbubble 4a and laser light is emitted, the brightness of the scattered light of the microbubble 4a hardly increases. In addition, when a variable magnetic field is applied to the charged microbubbles 4b, they disappear. Accordingly, if a variable magnetic field is applied to the microbubble 4b and laser light is emitted, the brightness of the scattered light of the charged microbubble 4b is zero.

The measuring device 7 can differentiate the microparticles 4a-4d by utilizing the fact that the microparticles 4a-4d behave differently if a variable magnetic field is applied to them.

The flow chart of Fig. 5 will be described below. Firstly, in S11, according to the video image of the Brownian motion trajectory of the particle before and after the application of the variable magnetic field, the measurement device 7 distinguishes the microparticles contained in the video image into uncharged microbubbles, charged microbubbles and solid particles. More specifically, the measurement device 7 distinguishes solid particles, charged microbubbles, and uncharged microbubbles, so that the measurement device 7 recognizes those microparticles whose luminance increases greater than a predetermined threshold when the variable magnetic field is applied as the solid particles, recognizes the microparticles that have disappeared and whose luminance becomes zero when the variable magnetic field is applied, as the charged microbubbles, and identifies the microparticles whose brightness does not increase greater than the predetermined threshold as the uncharged microbubbles when the variable magnetic field is applied.

In this S11, if the brightness of a scattered light S cannot be increased or saturated when the variable magnetic field is applied, preferably the measurement device 7 suspends subsequent calculations, and performs the steps shown in FIG. 4 again after changing the wavelength of the laser light of the laser device 3.

Then, in S12, before the variable magnetic field is applied, the measurement device 7 counts the respective numbers of the uncharged microbubbles, the charged microbubbles, and the solid particles identified in the dynamic image of the Brownian motion trajectory of the microparticles in S11, so that the measurement device 7 calculates the uncharged microbubble number concentration _Cbo , the charged microbubble number concentration _Cbc , and the solid particle number concentration Csolid _{in the liquid to} be tested.

Then, in S13, before applying the variable magnetic field, the measurement device 7 analyzes the Brownian motion trajectory of the microparticles according to the dynamic image of the Brownian motion trajectory of the microparticles, whereby the measurement device 7 calculates the particle diameters of the microparticles counted in S12 from the uncharged microbubbles, the charged microbubbles and the solid particles. More specifically, the Brownian motion velocity of the microparticles dispersed in the object to be measured becomes slower as the particle size becomes larger, and becomes faster as the particle size becomes smaller. The particle size of each particle can be calculated by analyzing the Brownian motion trajectory of the above-mentioned particles.

Then, in S14, using the particle size information of each particle calculated from the uncharged microbubbles, the charged microbubbles and the solid particles in S13, the measuring device 7 calculates the particle size distribution _Dbo of the uncharged microbubbles dispersed in the liquid to be tested, the particle size distribution _Dbc of the charged microbubbles, and the particle size distribution Dsolid of the solid _particles . Second specific embodiment

Then, the configuration of the measurement system 1A to which the method for measuring microbubble dispersion liquid according to the second embodiment of the present invention is applied will be described in detail with reference to the drawings.

FIG. 7 is a schematic diagram of a partial configuration of the measurement system 1A according to this embodiment. The measurement system 1A further provides the measurement system 1 with an electrophoretic device 9 according to the first embodiment. Please note that among the components of the measuring system 1A in FIG. 7 , neither a variable magnetic field applying device 5 nor a measuring device 7 is shown. Hereinafter, the same configuration as the measurement system 1 of the first embodiment will be omitted from illustration and detailed description.

The electrophoresis device 9 includes: a bracket 91, which horizontally supports a microcapillary 2; a pair of electrode support members 92, 93, which are arranged on the two ends of the microcapillary 2; and a DC power supply (not shown). The bracket 91 is columnar. The upper surface 911 of the bracket 91 is provided with a supporting groove, which extends along the extending direction of the microcapillary 2 and has an arc-shaped cross section. The microcapillary 2 is arranged in the device 9 along the support groove. In addition, the bracket 91 is provided with a circular cutout 912 in a plan view at its approximate center (ie near an irradiation area A of a laser light L).

Each side of the electrode supporting members 92, 93 (the surface facing the microcapillary 2) is provided with needle-shaped electrodes 92a, 93a. These electrodes 92a, 93a are respectively connected to the positive and negative poles of the DC power supply. In addition, these electrode supporting members 92, 93 are configured such that the members 92, 93 can approach each other or move away from each other along the extending direction of the microcapillary 2. If the electrode support members 92, 93 are close to each other, the electrodes 92a, 93a are each inserted into the respective ends of the conduit 2a of the microcapillary 2.

FIG. 8 is a flow chart of the specific steps of the measurement method for measuring the property of the liquid to be measured using the measurement system 1A of this specific embodiment. In the flow chart of FIG. 8 , since the processing steps of S11-S12, S14-S16 and S18-S19 are the same as those of S1-S8 in the flow chart of FIG. 4 , they are not repeated here.

After the liquid to be tested is contained in the microcapillary 2 in S12, the operator moves the electrode support members 92, 93 close to each other in S13 to insert the electrodes 92a, 93a into the two ends of the conduit 2a of the microcapillary 2.

After taking a dynamic image of the irradiated area A with a digital microscope 6 in S16, the operator turns on the power supply connected to the electrodes 92a, 93a for a predetermined period of time in S17 to supply an electric field to the liquid to be tested in the irradiated area A between the electrodes 92a, 93a for a predetermined period of time.

In S19, the digital microscope 6 is used to capture the dynamic image and the laser device 3 is used to emit the laser light L. In S20, the operator operates the measuring device 7 to calculate the concentration and particle size distribution of the microparticles according to the microparticle dynamic image data obtained by the digital microscope 6.

In this method, the steps for distinguishing the microparticles into solid particles and microbubbles according to the dynamic image data obtained by the digital microscope 6 and calculating the particle number concentration and the particle size distribution of these solid particles and microbubbles are the same as those shown in FIG. 5 , so detailed descriptions thereof will be omitted.

In addition, according to the measurement method of this specific embodiment, by applying the electric field for a predetermined time, a dynamic image is obtained when an electric field is applied in S17, and the dynamic image is the electrophoretic trace when the electric field is applied to the microparticle. Therefore, in S20, the microparticles are identified as solid particles and micro-bubbles, and the electrical properties of the solid particles are measured by analyzing the moving speed of the solid particles contained in the liquid to be tested according to the dynamic image when the electric field is applied. Third specific embodiment

Then, the configuration of a measurement system 1B to which the method for measuring a microbubble dispersion according to the third embodiment of the present invention is applied will be described in detail with reference to the drawings.

FIG. 9 is a schematic diagram of a partial configuration of the measurement system 1B according to this embodiment. The measurement system 1B is configured such that an electrophoretic device 9B is further provided in the measurement system 1 of the first embodiment. Please note that in FIG. 9, a variable magnetic field applying device 5 and a measuring device 7 are not shown among the components of the measuring system 1B. The illustration and detailed description of the same configuration as the measurement system 1 measured in the first embodiment will be omitted below.

The electrophoresis device 9B includes: a pair of electrode support covers 95, 96, which are located at both ends of a microcapillary 2; a stand (stand) (not shown), used to vertically carry the microcapillary 2; and a power supply (not shown).

Needle-shaped electrodes 95a, 96a are respectively provided in the electrode support covers 95, 96. Therefore, if these electrode supporting caps 95, 96 are mounted to both ends of the microcapillary 2, the electrodes 95a, 96a are each inserted into each end of the conduit 2a of the microcapillary 2.

The specific steps of the measuring method for measuring the properties of a liquid to be tested using the above-mentioned measuring system 1B are the same as those in the flow chart of FIG. 8 , and detailed descriptions are omitted here.

Although some specific embodiments of the present invention have been described above, the present invention is not limited to these specific embodiments. The configuration details of this embodiment can be changed as desired within the scope of the present invention.

For example, in the first embodiment, after the microparticles are identified as uncharged microbubbles, charged microbubbles and solid particles according to the dynamic images before and after applying a variable magnetic field (see S11 in FIG. 15 ), the particle size of each particle is calculated by analyzing the Brownian motion trajectory of the microparticles before the variable magnetic field is applied, but the method of calculating the particle size of the solid particles in the microparticles is not limited to this.

The number of rotations of solid particles is related to the degree of change in the brightness of scattered light when a variable magnetic field is applied. When a variable magnetic field is applied to the solid particle, the number of rotations of the solid particle is also related to the particle size of the solid particle and the viscosity of the medium. Therefore, the particle size of the solid particle can be calculated according to the change degree of the scattered light brightness, by using the correlation between the change degree of the scattered light brightness and the particle size of the solid particle and the viscosity of the medium.

More specifically, the graph of calculated solid particle sizes shown in FIG. 10 is based on previously performed tests to measure the correlation between the degree of change in brightness of scattered light before and after application of a variable magnetic field, and the particle sizes of solid particles in various media of different viscosity coefficients. Before and after applying the variable magnetic field, use the measurement device 7 to calculate the change degree of the scattered light brightness of the microparticles identified as solid particles according to the dynamic image of the microparticle trajectory. According to the brightness change of the scattered light and the viscosity coefficient of the medium input by the operator, the particle size used to calculate the particle size can be found in the legend, so that the particle size of the solid particle can be calculated.

1, 1A, 1B: Measuring system 2: Micro capillary (containment device) 2a: Conduit 21: rail plate 22: glass plate 23: Polymer parallel lines 3: Laser device (light source) 4a: Uncharged microbubbles 4b: Charged microbubbles 4c, 4d: solid particles 5: Variable magnetic field application device 51, 51A: coil pad 511, 512: round coil 52: subject 6: Digital microscope (light detection device) 7: Measuring device 8: Filtration device 9: Electrophoresis device 91: Bracket 911: The upper surface of the bracket 912: incision 92, 93: Electrode support parts 92a, 93a: electrodes 95, 96: Electrode support cover 95a, 96a: electrodes L: laser light S: scattered light A: Irradiation area S1, S2, S3, S4, S5, S6, S7, S8: steps S11, S12, S13, S14, S15, S16, S17, S18, S19, S20: Steps

FIG. 1 is a schematic configuration diagram of a microbubble dispersion measurement system according to a first embodiment of the present invention. Figure 2A is a perspective view of another example of a container. Fig. 2B is a perspective view of another example of a container. Fig. 2C is a perspective view of another example of a container. Figure 3 is a perspective view of a double coil type coil pad. FIG. 4 is a flow chart of specific steps of a measurement method for measuring the properties of a microbubble dispersion. Fig. 5 is a flow chart of steps for calculating particle concentration and particle size distribution using a measuring device. FIG. 6 is an illustration of an image of microparticles obtained by detecting scattered light of laser light with a digital microscope. FIG. 7 is a schematic diagram of a partial configuration of a measurement system according to a second embodiment of the present invention. FIG. 8 is a flow chart of specific steps of a measurement method for measuring the properties of a microbubble dispersion. FIG. 9 is a schematic diagram of a partial configuration of a measurement system according to a third embodiment of the present invention. Figure 10 is an exemplary diagram for calculating the particle size of solid particles.

1: Measuring system

2: Micro capillary (containment device)

3: Laser device (light source)

5: Variable magnetic field application device

51: coil pad

52: subject

6: Digital microscope (light detection device)

7: Measuring device

8: Filtration device

L: laser light

S: scattered light

A: Irradiation area

Claims (15)

A method for measuring the properties of a liquid to be tested, the liquid to be tested is a dispersion of microbubbles, the method comprising: irradiating the liquid to be tested contained in a container with an illuminating light; applying a time-varying magnetic field to the liquid to be tested in the area irradiated by the illuminating light; using a light detecting device to emit the illuminating light to detect scattered light generated by a plurality of microparticles contained in the liquid to be tested; and distinguishing the microparticles into microbubbles and solid particles according to the brightness of the scattered light detected by the light detecting device. The method according to claim 1, wherein the liquid to be tested contains microbubbles with a particle size ranging from 2nm to 2000nm. The method as claimed in claim 1 or 2, wherein the brightness of an image of the microparticles obtained by the photodetection device is compared with a predetermined threshold to identify the microparticles as solid particles and microbubbles. The method as described in claim 1, wherein in the step of detecting the scattered light, before and after applying a variable magnetic field, the scattered light measured by the photodetection device is used to obtain an image of the trajectory of the microparticles due to Brownian motion, and wherein in the image obtained by the photodetection device, the microparticles are identified as solid particles and microbubbles according to whether the brightness of the microparticles increases when the variable magnetic field is applied to the liquid to be tested. The method as described in claim 4, wherein in the image obtained by the photodetection device, when the variable magnetic field is applied to the liquid to be tested, the microparticles whose brightness increases are identified as solid particles The microparticles that disappeared were identified as charged microbubbles, and the microparticles that did not increase in brightness were identified as uncharged microbubbles. The method according to claim 1, further comprising measuring solid particles, wherein the concentration or particle size distribution of the solid particles contained in the liquid to be measured is calculated based on an image obtained by the light detection device. The method according to claim 5, further comprising measuring uncharged microbubbles, wherein the concentration or particle size distribution of the uncharged microbubbles contained in the liquid to be tested is calculated based on an image obtained by the photodetection device. The method according to any one of claims 4-7, further comprising measuring charged microbubbles, wherein in the step of detecting scattered light, the following two are obtained: a pre-application image of the Brownian motion trajectory of the microparticles before the variable magnetic field is applied to the liquid; and an application process image of the Brownian motion trajectory of the microparticles when the variable magnetic field is applied to the liquid, and the concentration or particle size distribution of the charged microbubbles contained in the liquid to be measured is calculated based on these images. The method according to claim 8, further comprising performing a first screening of the liquid to be tested, wherein the liquid to be tested is contained before the containing device, and the liquid to be tested has passed through a positively charged filter. The method according to any one of claims 4-7, wherein when the variable magnetic field is applied to the liquid, the particle size of the solid particle is calculated by using the image of the particle obtained by the photodetection device according to the degree of change in brightness of scattered light. The method as described in claim 1, further comprising applying an electric field to the liquid to be tested, applying the electric field to the liquid to be tested in the area irradiated by the illumination light, wherein the detection of scattering In the light step, when the electric field is applied to the liquid to be tested, an application process image of the microparticle electrophoretic trajectory is obtained, and the characteristics of solid particles contained in the liquid to be tested are measured according to the application process image. The method as claimed in claim 1, further comprising performing a second screening, wherein before applying the variable magnetic field to the liquid to be tested, a static magnetic field is applied to the liquid, and at least a part of the solid particles are moved out of the irradiation area by the static magnetic field. The method as claimed in claim 12, further comprising measuring the amount of paramagnetic substances, wherein the amount of paramagnetic particles is measured, and the solid particles are collected in the second screening step of applying the static magnetic field to the liquid to be tested. The method as claimed in claim 1, wherein the light source of the illumination light is a laser device, and the laser device can use two or more wavelength values in the range of 300nm to 700nm to switch the wavelength of the laser light (L). A measurement system for measuring the properties of a liquid to be tested, the liquid to be tested is a microbubble dispersion liquid, the system comprising: a containing device, which is used to contain the liquid to be tested; a light source, which irradiates the liquid to be tested contained in the containing device with an illuminating light; a variable magnetic field applying device, which applies a time-varying magnetic field to the liquid to be tested in an irradiated area with the illuminating light; a light detection device, which detects scattered light generated by microparticles contained in the liquid to be tested by the illuminating light; and a measuring device , which measures the property of the liquid to be tested, and distinguishes the microparticles into microbubbles and solid particles according to the brightness of the scattered light measured by the light detection device.