Patent Application
20200096424
The present invention relates to a liquid film generating tool, and more particularly to a tool for generating a liquid film as a liquid sample, in a system in which the liquid sample is placed in a path through which an electromagnetic wave propagates and characteristics of electromagnetic waves transmitted through the liquid sample is measured.
In related art, there has been provided a spectroscopic apparatus that measures characteristics of a substance, using an electromagnetic wave such as a terahertz wave. For example, an absorption spectroscopy has been known in which the electromagnetic wave is allowed to transmit through a sample to be subjected to spectroscopic measurement, and characteristics of the sample are measured from changes in electromagnetic waves caused by an interaction between the electromagnetic waves and the sample while passing through the sample.
In the absorbance spectroscopy, for example, in order to perform a measurement with high accuracy on a liquid sample having a strong absorption effect, it is necessary to form a thin liquid sample to such an extent that the electromagnetic waves transmit. In particular, when spectroscopically measuring the liquid sample with the terahertz wave, since the absorption effect of the terahertz wave due to the water molecule is strong, in order to prevent deterioration of an SN ratio of a measurement signal, it is required to make the liquid into a plate-like uniform thin film, and to cause the terahertz wave to transmit through the plate-like portion to perform the measurement.
In general, in the measurement of the liquid sample, the sample is sandwiched in containers (generally called solution cells) made of a material such as a glass through which the electromagnetic waves transmit, the electromagnetic waves are incident from the outside of the solution cell, and the electromagnetic waves transmitted through the solution cell are measured. However, when the liquid sample is sandwiched between solution cells and measured, spectroscopic information of the cell material is superimposed as noise on the spectroscopic information of the liquid sample, which interferes with measurement of true spectroscopic information.
In related art, in view of such a problem, apparatuses aiming at making it possible to measure the spectroscopic information with little noise without using a solution cell have been proposed (see, for example, Patent Documents 1 and 2). In the apparatuses described in Patent Documents 1 and 2, by ejecting the liquid sample from a nozzle by the pressure of a pump, using the nozzle having a special structure, a thin flat plate-like liquid film is generated.
That is, as illustrated in FIG. 4 of Patent Document 2, two string-like fluid columns are formed by the liquid ejected from the tip of the nozzle. The two string-like fluid columns collide with each other at a fluid column assembly point, while drawing a smooth arc, and a liquid film is formed by surface tension of the liquid generated between the two fluid columns from the tip of the nozzle to the fluid column assembly point.
However, in the case of a liquid having a low surface tension such as a surfactant, there has been a problem of difficulty in forming a thin liquid film by ejecting the liquid sample. Further, there is a need for a certain amount or more of a liquid sample to continue to generate a thin liquid film due to the ejection of the liquid sample for a period of time required for measuring the terahertz wave. For this reason, there is a problem of difficulty in measuring spectroscopic information using the liquid, which is difficult to collect a certain amount or more, as a sample.
The invention has been made to solve such a problem, and an object of the invention is to allow formation of a liquid film even from a liquid having a low surface tension. Further, another object of the invention is to allow generation of a liquid film continuously for a period of time required for measuring a terahertz wave, even from a liquid of less than a certain amount.
In order to solve the above-mentioned problem, the liquid film generating tool of the invention includes a flat plate-like space region having a predetermined thickness. Here, the planar shape of the space region is configured in such a shape that the surface tensions generated, by the liquid supplied to the space region, from the different places of the contour portion of the space region toward the inner side of the space region interact with each other.
According to the invention configured as described above, when a liquid is supplied to the space region of the liquid film generating tool from the outside, the liquid spreads in a plate shape along the shape of the space region. Surface tension is generated from the different places of the contour portions of the space region toward the inside of the space region, in the liquid that spreads in the plate shape in the space region. According to the invention, since the space region is formed in such a shape that the surface tensions generated from the different places of the contour portions of the space region interact with each other, even in the case of the liquid in which, if the liquid film generating tool is not used, the surface tension is insufficient, and the liquid film cannot be formed, the liquid spreads in a plate shape along the shape of the space region, and a liquid film can be formed. Thus, according to the invention, it is possible to generate a liquid film even from a liquid having a low surface tension.
Hereinafter, a first embodiment of the invention will be described with reference to the drawings.
First, a configuration of the liquid film generating apparatus 200 for generating a sample liquid film to be measured by a terahertz spectrometer will be described with reference to
The liquid film cartridge 205 is provided with a nozzle 206 for ejecting the liquid to generate a sample liquid film, and the liquid film generating tool 100A according to the first embodiment. For the nozzle 206, for example, it is possible to use the liquid film generating nozzle described in Patent Document 2, but it is not limited thereto. The configuration of the liquid film generating tool 100A will be described later in detail with reference to
The tube pump 202 sucks up the liquid to be measured from the recovery tank 201a via the backward passage piping 204, pressurizes the sucked up liquid, and derives the liquid to a liquid film cartridge 205 via the forward passage piping 203. The liquid film cartridge 205 ejects the liquid derived by the tube pump 202 from the nozzle 206 and assists the flow of the ejected liquid by the liquid film generating tool 100A, thereby generating a plate-like sample liquid film having a flat surface in a space. The recovery tank 201a recovers and stores the liquid flowing down from the liquid film cartridge 205.
In a case where an amount of liquid that can continue to be ejected from the nozzle 206 is stored in the recovery tank 201a for the period of time required for measuring the terahertz wave from the beginning, it is not indispensable to suck up again and circulate the liquid recovered from the liquid film cartridge 205 to the recovery tank 201a. On the other hand, in a case where the amount of the liquid stored in the recovery tank 201a is less than the amount that can continue to eject liquid from the nozzle 206 for the period of time required for measuring the terahertz wave, it is necessary to circulate and use the liquid.
It should be noted that the liquid film cartridge 205 itself may be used as a container without providing the container 201, and the bottom of the liquid film cartridge 205 may be closed and used as a recovery tank. In this case, the backward passage piping 204 is disposed in the recovery tank provided at a lower part of the liquid film cartridge 205. This structure is particularly effective when a relatively small amount of liquid is used as a sample like the latter.
Next, the configuration of the liquid film generating tool 100A according to the first embodiment will be described with reference to
As illustrated in
The water flow of the two fluid columns is assisted by a planar shape of the space region 13A, and a liquid film is formed in the space region 13A. The space region 13A serves as an opening portion penetrating from the front surface to the rear surface of the liquid film generating tool 100A, and it is possible to allow the terahertz wave to pass through the liquid film formed here.
The space region 13A has a predetermined thickness. This thickness is designed to be approximately the same as or slightly larger than the diameter of the fluid column formed by the liquid ejected from the nozzle 206.
The planar shape of the space region 13A has a line symmetrical shape on both sides with a center line 101A connecting a center point of the inflow port 11A and the center point of the outflow port 12A as a boundary. A contour of the planar shape of the space region 13A has an arcuate shape that gradually widens toward the outside from the inflow port 11A and then gradually narrows toward the inside to terminate at the outflow port 12A on both sides from the center line 101A. The contour shape of the space region 13A is a shape that assists the water flow of the two string-like fluid columns generated by the nozzle 206 to promote the formation of a liquid film.
When the surface tension is sufficiently large, the surface tensions generated inward from the fluid columns 301 and 302 on the both sides are in a relation of interacting on each other even at the location away from the nozzle 206. Therefore, the two string-like fluid columns 301 and 302 collide with each other at a fluid column assembly point 303, while drawing a smooth arc, and the liquid film 304 is formed by the surface tension of the liquid between the nozzle 206 and the fluid column assembly point 303.
On the other hand, as illustrated in
The planar shape of the space region 13A is configured to have a shape capable of forming a liquid film as illustrated in
That is, the liquid ejected from the nozzle 206 is input from the inflow port 11A in a state in which two string-like fluid columns are formed. The two fluid columns flow along the contour shape of the space region 13A. In this case, inward surface tension is generated from the two fluid columns flowing along the contour shape. Although the surface tension decreases as it goes away from the nozzle 206, the flow of the fluid column is forcibly regulated by the contour shape of the space region 13A and merges at the outflow port 12A. That is, even when the surface tension is small at a position away from the inflow port 11A, there is a relation in which the small surface tensions interact with each other. Thus, the two fluid columns merge at the outflow port 12A. As a result, a liquid film is formed by the surface tension of the liquid between the inflow port 11A and the outflow port 12A.
An outlet flow path 14A is formed ahead of the outflow port 12A. After the two fluid columns merge at the outflow port 12A, the dropletized liquid flows through the outlet flow path 14A, flows down from the liquid film cartridge 205, and is recovered in the recovery tank 201a.
As described in detail above, according to the liquid film generating tool 100A of the first embodiment, when a liquid is supplied from the external nozzle 206 to the space region 13A, two fluid columns are formed along the contour shape of the space region 13A, and liquid spreads in a plate shape between the fluid columns. Surface tension is generated from the fluid column flowing along the contour portions on both sides of the space region 13A toward the inside of the space region 13, in the liquid that spreads in the plate shape in the space region 13A. According to the first embodiment, since the space region 13A is formed in such a shape that the surface tensions of the liquids generated from the contour portions on both sides of the space region 13A interact with each other, even in the case of the liquid in which, if the liquid film generating tool 100A is not used, the surface tension is insufficient and the liquid film cannot be formed, the liquid spreads in a plate shape along the shape of the space region 13A, and a liquid film can be formed. Thus, according to the first embodiment, it is possible to generate a liquid film even from a liquid having a low surface tension.
Next, a second embodiment of the invention will be described with reference to the drawings.
As illustrated in
The water flow of the two fluid columns is assisted by the planar shape of the space region 13B, and a liquid film is formed in the space region 13B. The space region 13B is an opening portion penetrating from the front surface to the rear surface of the liquid film generating tool 100B, and it is possible to allow the terahertz wave to pass through the liquid film formed here.
The space region 13B according to the second embodiment also has a predetermined thickness. This thickness is designed to be approximately the same as or slightly larger than the diameter of the fluid column generated in the space region 13B.
The planar shape of the space region 13B is a shape which is line-symmetrical on both sides with the center line 101B connecting the center point of the inflow port 11B and the center point of the outflow port 12B as a boundary. Similarly to the space region 13A according to the first embodiment, the contour of the planar shape of the space region 13B also has an arcuate shape that gradually widens toward the outside from the inflow port 11B and then gradually narrows toward the inside to terminate at the outflow port 12B on both sides from the center line 101B. The contour shape of the space region 13B is a shape that assists the water flow of the two string-like fluid columns to promote the formation of the liquid film.
That is, the two string-like fluids generated in the space region 13B flow along the contour shape of the space region 13B. In this case, inward surface tension is generated from the two fluid columns flowing along the contour shape. Although the surface tension decreases as it goes away from the inflow port 11B, the flow of the fluid column is forcibly regulated by the contour shape of the space region 13B and merges at the outflow port 12B. That is, even when the surface tension is small at a position away from the inflow port 11B, the small surface tensions interact with each other. Thus, the two fluid columns merge at the outflow port 12B. As a result, a liquid film is formed by the surface tension of the liquid between the inflow port 11B and the outflow port 12B.
An outlet flow path 14B is formed ahead of the outflow port 12B. After the two fluid columns merge at the outflow port 12B, the dropletized liquid flows through the outlet flow path 14B, flows down from the liquid film cartridge 205, and is recovered in the recovery tank 201a.
As described in detail above, in the liquid film generating tool 100B of the second embodiment, the space region 13B is also formed in such a shape that the surface tensions of the liquids generated from the contour portions on both sides of the space region 13B interact with each other. Thus, even in the case of the liquid in which, if the liquid film generating tool 100B is not used, the surface tension is insufficient and the liquid film cannot be formed, the liquid spreads in a plate shape to conform to the shape of the space region 13B, and a liquid film can be formed. Thus, according to the second embodiment, it is possible to generate a liquid film even from a liquid having a low surface tension.
In the second embodiment, the configuration in which the liquid film generating tool 100B includes the inflow port 11B, the outflow port 12B, the inlet flow path 15B and the outlet flow path 14B has been described, but these are not indispensable configurations in the second embodiment. Also, it is not indispensable to apply to the liquid film generating apparatus 200 having the configuration illustrated in
Next, a third embodiment of the invention will be described with reference to the drawings.
As illustrated in
The space region 13C in the third embodiment has a plurality of closed space regions 17C. Each of the closed space regions 17C is an opening portion penetrating from the front surface to the rear surface of the liquid film generating tool 100C, and it is possible to allow the terahertz wave to pass through the liquid film formed here.
The space region 13C according to the third embodiment also has a predetermined thickness. This thickness is designed to a value as small as possible so that the structure of the liquid film generating tool 100C can be maintained and the thickness is close to the thickness of the liquid film that is desired to be generated.
The space region 13C in the third embodiment is configured such that the plurality of closed space regions 17C is arranged adjacent to each other at an interval less than a predetermined distance. It is preferable to design the interval of the closed space regions 17C to a value as small as possible within a range in which the structure of the liquid film generating tool 100C can be maintained. This is because the portion between the closed space regions 17C is a portion which is not opened and does not allow the terahertz wave to pass through, so that the region of this portion is made as narrow as possible.
Each of the plurality of closed space regions 17C is configured in a shape in which, about the surface tension which is generated in the liquid supplied to the closed space region 17C and which is directed from the contour portion of the closed space region 17C toward the inside of the closed space region 17C, the surface tensions generated from different places in the contour portion of the closed space region 17C interact with each other. For example, each of the plurality of closed space regions 17C is formed in a honeycomb shape. All the honeycomb shapes have the same shape and the same size.
In the case of the honeycomb shape, as illustrated in
When the wavelength of the terahertz wave is set to 0.3 mm, the focus cannot be narrowed down to 0.3 mm or less due to its physical factor. Therefore, it is necessary to set the generated liquid film to be larger than the width of 0.3 mm. When considering the wavelength band of the terahertz wave to be 0.03 to 3.0 mm, it is necessary to set the liquid film to be generated to be larger than the maximum wavelength of 3.0 mm. Further, it is also necessary to consider the positional deviation at the time of installation of the liquid film generating tool 100C or the occurrence of diffraction phenomenon of light. Therefore, the opposite side dimension of the honeycomb shape constituting the closed space region 17C may be set to a value (for example, about 10 mm) larger than 3.0 mm, in consideration of these points.
In a case where the closed space region 17C is formed in a honeycomb shape, each closed space region 17C is arranged adjacent to each other at positions such that their respective sides are opposite to each other. Further, the arrangement interval is set to be less than the predetermined distance as described above. In this way, as a whole body of the plurality of closed space regions 17C, while securing a large total area of the region of the portion through which the terahertz wave passes, the area of the portion through which the terahertz waves do not pass between the closed space regions 17C can be made as narrow as possible.
As described in detail above, also in the liquid film generating tool 100C of the third embodiment, the space region 13C is formed in a such shape that the surface tensions of the liquids generated from the contour portions of the respective closed space regions 17C constituting the space region 13C interact with each other. Thus, even in the case of the liquid in which, if the liquid film generating tool 100C is not used, the surface tension is insufficient and the liquid film cannot be formed, the liquid spreads in a plate shape to follow the shape of the closed space region 17C, and the liquid film can be formed. Thus, according to the third embodiment, it is possible to generate a liquid film even from a liquid having a low surface tension.
Further, in the third embodiment, the honeycomb shape is illustrated as the shape of the closed space region 17C, but the invention is not limited thereto. For example, a triangle, a quadrangle, a pentagon, an octagon, a circle, or the like may be adopted.
Further, in the third embodiment, the configuration in which the liquid film generating tool 100C includes the inflow port 11C, the outflow port 12C, the inlet flow path 15C, and the outlet flow path 14C has been described. However, these are not indispensable configurations in the third embodiment. Also, it is not indispensable to apply to the liquid film generating apparatus 200 having the configuration illustrated in
Further, in the third embodiment, the example in which the plurality of closed space regions 17C is configured to have the same shape and the same size has been described, but the invention is not limited thereto. For example, each of the plurality of closed space regions may be configured to have the same shape and sizes which permit different sizes. For example, a fractal pattern may be formed by a plurality of closed space regions. Alternatively, a pattern corresponding to white noise may be generated on the power spectrum of the two-dimensional Fourier, and the pattern may be subjected to inverse Fourier transformation, thereby forming the plurality of closed space regions.
Further, in the first to third embodiments, processing such as coating the surfaces of the liquid film generating tools 100A to 100C with a specific material may be performed depending on the liquid sample to be used.
Besides, all the first to third embodiments described above are merely examples of implementation of the invention, and the technical scope of the invention should not be interpreted restrictively by the embodiments. That is, the invention can be implemented in various forms without departing from the gist or the main features thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-098733 | May 2017 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2018/018900 | 5/16/2018 | WO | 00 |
