How to visualize bubbles

Abstract

To provide a method for imaging air bubbles, capable of detecting the diameters, shapes and behaviors of fine air bubbles included in a liquid with high accuracy.SOLUTION: A method for imaging air bubbles, capable of imaging the air bubbles included in a liquid comprises: a preparation step of preparing a disc having a surface charged in a plus electric charge; a dropping step of dropping the liquid including the air bubbles on the surface of the disc to form a droplet; a scanning step of putting the disc having the deposited droplet into a cell having the inserted liquid to drive the cantilever of an atomic force microscope and scan the air bubbles existing on the surface of the disc; and an imaging step of imaging the air bubbles on the basis of the scan data acquired in the scanning step.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for imaging fine air bubbles, and more particularly to a technique for imaging fine air bubbles having a diameter of less than 1 μm. [Background technology]

[0002] In recent years, attempts have been made to utilize technology using fine bubbles in liquids in a wide range of fields, including food, drinking water, cosmetics, medicine, pharmaceuticals, agriculture, plant cultivation, cleaning, and water treatment. The International Organization for Standardization (ISO) defines bubbles with a diameter of less than 100 μm as fine bubbles, and bubbles with a diameter of less than 1 μm as ultrafine bubbles. In addition, a method for measuring the size of fine particles present in liquid is disclosed in Patent Document 1.

[0003] Patent Document 1 discloses that information such as the brightness and spectral characteristics of nanoparticles contained in a liquid is obtained by nanoparticle tracking analysis (NTA), and further, information on the particle size of the nanoparticles is obtained by dynamic light scattering (DLS), and information on the size and distribution of the nanoparticles is obtained based on this information. However, the technique disclosed in Patent Document 1 has a problem in that it is difficult to measure the shape and behavior (changes over time) of bubbles contained in a liquid. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2014-521967 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, the technology described in Patent Document 1 makes it difficult to obtain information about the shape and behavior of fine bubbles, and there has been a growing demand to detect the shape and behavior of fine bubbles with high accuracy.

[0006] The present invention has been made to solve these conventional problems, and its object is to provide a bubble imaging method that is capable of detecting the shape and behavior of microscopic bubbles contained in a liquid with high accuracy. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, a first invention is a method for imaging air bubbles contained in a liquid, comprising the steps of: a preparation step of preparing a disk having a positively charged surface; a dripping step of dripping the liquid containing air bubbles onto the surface of the disk to adhere the droplets; a scanning step of immersing the disk with the droplets adhered to it in a cell containing the liquid and driving the cantilever of an atomic force microscope to scan the air bubbles present on the surface of the disk; and an imaging step of imaging the air bubbles based on the scanning data acquired by the scanning step.

[0008] Further, a second invention is a bubble imaging method for imaging bubbles contained in a liquid, comprising: a preparation step of fixing a measurement sample of an object to be tested for its reaction with the liquid to a sample stage; a dripping step of dripping the liquid onto a surface of the measurement sample to adhere the liquid to the measurement sample and soft-land the bubbles on the surface of the measurement sample; a scanning step of immersing the measurement sample with the liquid adhered to it in a cell into which the liquid has been inserted and driving the cantilever of an atomic force microscope to scan the bubbles that have soft-landed on the surface of the measurement sample; and an imaging step of imaging the bubbles based on the scanning data acquired in the scanning step. Effect of the Invention

[0009] The bubble imaging method according to the present invention makes it possible to detect with high accuracy the shape and behavior of minute bubbles contained in a liquid, and also to detect with high accuracy the shape and behavior of bubbles in a non-bulk state. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is an explanatory diagram illustrating a processing procedure of an imaging method according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is an explanatory diagram showing a schematic configuration of an atomic force microscope. [Diagram 3] FIG. 3 is a flowchart showing the processing steps of the imaging method according to the first embodiment of the present invention. [Figure 4] FIG. 4 is an explanatory diagram showing a schematic diagram of negative and positive charges generated on the surface of the disk. [Diagram 5] FIG. 5 is an explanatory diagram that shows a schematic diagram of how air bubbles contained in the UFB solution are attracted to the disk. [Figure 6] FIG. 6 is an explanatory diagram that illustrates a processing procedure of the imaging method according to the second and third embodiments of the present invention. [Figure 7] FIG. 7 is a flowchart showing the processing steps of an imaging method according to the second embodiment of the present invention. [Figure 8] FIG. 8 is a flowchart showing the processing steps of an imaging method according to the third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] [First embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is an explanatory diagram showing a typical procedure of an imaging method according to a first embodiment of the present invention, Fig. 2 is an explanatory diagram showing a schematic diagram of the principle of an atomic force microscope used to image bubbles in a liquid, and Fig. 3 is a flowchart showing the procedure of the imaging method according to the first embodiment.

[0012] [Outline of atomic force microscope] As shown in FIG. 2, an atomic force microscope (AFM) 100 irradiates a laser beam output from a laser oscillator 101 onto the back surface of a cantilever 102 provided with a probe 102a for scanning a sample P. The laser beam reflected from the back surface of the cantilever 102 is detected by a position sensitive detector (PSD) 103 using, for example, a four-division photodiode, and the detection signal is amplified by an amplifier 104 to detect the amount of displacement due to the interaction between the cantilever 102 and the sample P. Note that the detailed configuration and operation of the atomic force microscope 100 are well-known techniques as described in, for example, JP 2019-117110 A, and therefore detailed descriptions of the configuration and operation will be omitted.

[0013] In the first embodiment, fine bubbles or ultra-fine bubbles (hereinafter collectively referred to as "bubbles") contained in a liquid (e.g., water) are imaged using an atomic force microscope 100 shown in Fig. 2, and the diameters of the bubbles are measured based on the image data. The process of measuring the diameters of the bubbles will be described in detail below with reference to Figs. 1 and 3.

[0014] [Processing procedure of the first embodiment] First, as shown in Fig. 1(a), a disk 12 is placed on the surface of a sample stage 11, and then the disk 12 is bonded to the surface of the sample stage 11 with nail polish (adhesive). The sample stage 11 is made of, for example, cylindrical glass. The diameter of the cylinder is, for example, 1.5 mm. The disk 12 is, for example, a mica disk made of mica.

[0015] Mica has a laminated structure. Therefore, for example, by attaching an adhesive sheet such as cellophane tape to the surface of the mica and then peeling off the sheet, the mica surface is cleaved, resulting in a smooth surface that is free of impurities. It is also possible to use materials other than mica that have a smooth surface at the atomic level, such as polished sapphire, as the material for forming the disk 12.

[0016] 1(b), a 0.1% APTES solution 21 (aqueous solution of 3-aminopropyltriethoxysilane) is dropped onto the surface of the disk 12. As a result, a droplet (sometimes called a meniscus) of the APTES solution 21 is formed on the surface of the disk 12. Then, the disk is left to stand in a humid environment (preparation step; step S11 in FIG. 3).

[0017] As is well known, the disk 12 made of mica is negatively charged. Also, the APTES solution 21 is positively charged. Fig. 4 is an explanatory diagram showing a schematic diagram of the charges present on the surface of the disk 12. As shown in Fig. 4, a negative charge is generated on the surface of the disk 12, and a positive charge is generated at the portion of the APTES solution 21 that comes into contact with the disk 12.

[0018] 1(c), the droplets of the APTES solution 21 are removed by spraying compressed air onto the APTES solution 21 on the disk 12 using an air duster or the like (step S12). As a result, the APTES solution 21 is removed from the disk 12, but the positive charge still remains on the disk 12.

[0019] In this embodiment, an example is described in which the APTES solution 21 is dropped onto the disk 12 formed of mica to positively charge the surface of the disk 12, but any method other than the method of dropping the APTES solution 21 may be used as long as it is a method for positively charging the surface of the disk 12. As an example of a solution other than the APTES solution 21, a poly-L-lysine solution may also be used. Furthermore, if a material having a positively charged surface is used as the disk 12, it is not necessary to drop the APTES solution 21.

[0020] After removing the droplets of the APTES solution 21, a liquid 22 containing bubbles to be measured (hereinafter referred to as "UFB solution 22") is promptly dropped onto the disk 12 as shown in FIG. 1(d) (dropping step; step S13). That is, a dropping step is performed in which the UFB solution 22 is dropped onto the surface of the disk 12 to adhere droplets 22a. As a result, droplets 22a (measurement sample) of the UFB solution 22 are formed on the disk 12. The UFB solution 22 is, for example, ultrapure water containing bubbles.

[0021] FIG. 5 is an explanatory diagram that shows a schematic diagram of the charges contained in the disk 12 and the UFB solution 22. As shown in FIG. 5, the air bubbles 23 contained in the UFB solution 22 are negatively charged in many cases. Therefore, the negatively charged air bubbles 23 are attracted to the positive charges present on the surface of the disk 12. That is, the air bubbles 23 contained in the droplets 22a are attracted to the surface of the disk 12. The air bubbles 23 attracted to the surface of the disk 12 make a soft landing on the surface of the disk 12. In other words, the air bubbles 23 are in a state where they can move freely on the surface of the disk 12 and are present on the surface of the disk 12 without interfering with the reaction or decomposition.

[0022] Thereafter, as shown in FIG. 1( e ), the disk 12 on which the droplet 22 a is formed as a measurement sample is placed on the surface of a sample stage 32 on a high-speed AFM scanner 31 .

[0023] 1(f), the UFB solution 22 is poured into the depression 33a formed in the observation solution cell 33 (step S14), and the surface of the high-speed AFM scanner 31 is oriented diagonally downward to immerse the droplet 22a in the UFB solution 22. Furthermore, the surface of the disk 12 is made to face the probe 102a of the cantilever 102 mounted on the atomic force microscope 100. In FIG. 1(f), the UFB solution 22 poured into the observation solution cell 33 is raised upward due to the meniscus.

[0024] In this state, the high-speed AFM scanner 31 is driven to scan the surface of the disk 12 with the cantilever 102 (scanning step; step S15). For example, scanning is performed at a speed of 0.5 fps (one frame per two seconds). The probe 102a of the cantilever 102 is displaced along the air bubble 23 present on the surface of the disk 12. Therefore, the air bubble 23 can be imaged by the atomic force microscope 100 (imaging step; step S16). That is, an imaging step is performed to image the air bubble based on the scanning data acquired by the scanning step.

[0025] Thereafter, the diameter of the bubble 23 is measured based on the image of the bubble 23. If the bubble 23 is spherical, the diameter of the bubble 23 can be measured. If the bubble 23 is ellipsoidal, the major axis and minor axis can be measured. Even if the bubble 23 has an irregular shape other than a sphere or an ellipsoid, it is possible to image the shape and measure the size.

[0026] Furthermore, by performing high-speed AFM, it is possible to obtain many still images in a short time, and therefore it is possible to obtain a video showing the temporal change of the bubbles 23 contained in the UFB solution 22.

[0027] [Effects of the first embodiment] As described above, in the bubble imaging method according to this embodiment, a positively charged solution such as the APTES solution 21 is dropped onto the surface of the disk 12 to positively charge the surface of the disk 12. Then, droplets 22a of the UFB solution 22 to be measured are attached to the surface of the disk 12. As a result, the bubbles 23 contained in the UFB solution 22 can be attracted to the surface of the disk 12. In other words, the bubbles 23 can be softly landed on the surface of the disk 12.

[0028] In this state, by scanning with the high-speed AFM scanner 31, it is possible to image the shape of the bubbles 23 attracted to the surface of the disk 12, and based on this image, it is possible to measure the particle size, concentration, distribution, and behavior of the bubbles 23. Specifically, it is possible to measure the diameter of extremely fine bubbles 23 of less than 1 μm.

[0029] In addition, by using the high-speed AFM, it is possible to obtain a video of the bubbles 23 contained in the UFB solution 22. This makes it possible to observe the change in the shape of the bubbles 23 over time and the behavior of the bubbles 23. Furthermore, by using the high-speed AFM, it is possible to image the bubbles 23 without being affected by the deformation of the bubbles 23 caused by the bubbles 23 being attracted to the surface of the disk 12. Furthermore, it is possible to measure not only the diameter of the bubbles 23 but also the shape of the bubbles 23, such as the unevenness.

[0030] In addition, after a droplet 22a of UFB solution 22 is attached to the surface of disk 12, this droplet 22a is immersed in UFB solution 22 filled in recess 33a of observation solution cell 33, so that it is possible to prevent impurities from adhering to the surface of disk 12, enabling high-precision observation.

[0031] Furthermore, since mica is attached to the sample stage 11 and then the mica is cleaved to form the disk 12, the surface of the disk 12 can be made smooth at the atomic level and the adhesion of impurities can be prevented.

[0032] In the above-described embodiment, an example was described in which mica was cleaved to form the disk 12, and then the APTES solution 21 was dripped onto the surface of the disk 12 to positively charge the surface of the disk 12. However, if a material with a positively charged surface is used, it is possible to omit the step of dripping the APTES solution 21.

[0033] [Second embodiment] Next, a second embodiment of the present invention will be described. In the second embodiment, as in the first embodiment, an image of bubbles contained in a UFB solution is obtained using an atomic force microscope 100 shown in Fig. 2. Therefore, a description of the configuration of an apparatus for carrying out the imaging method according to the second embodiment will be omitted.

[0034] In the above-described first embodiment, the measurement of the particle size, concentration, distribution, and behavior of bubbles in a state where the bubbles are not in contact with the interface of an object (for example, an object to be cleaned), i.e., in a bulk state, has been described. In the second embodiment, an example of measuring the particle size, concentration, distribution, and behavior of bubbles in a non-bulk state will be described.

[0035] That is, UFB solutions have started to be used in many fields recently. When UFB solutions are used, bubbles in the UFB solution always come into contact with some object. Therefore, in addition to measuring bubbles in the bulk state described above, it is required to measure the particle size, concentration, distribution, and behavior of bubbles in a non-bulk state.

[0036] In the second embodiment, a toilet bowl is taken as an example of an object that comes into contact with bubbles in the UFB solution (an object to be cleaned that reacts with the UFB solution), and a processing procedure for cleaning a measurement sample simulating a toilet bowl and limescale attached to its surface with a UFB solution will be described. That is, toilet bowls are generally made of pottery sintered with clay and water, and limescale adheres to the surface of the pottery over time. Limescale is mainly composed of calcium carbonate, which accumulates on the surface of the pottery to become limescale. In the second embodiment, an aqueous solution containing calcium carbonate (an aqueous solution containing dirt components) is dropped onto a sample piece of pottery to generate a measurement sample with limescale deposited on the surface of the pottery. An image is generated of the process of cleaning the limescale of this measurement sample with a UFB solution.

[0037] Fig. 6 is an explanatory diagram that shows a schematic procedure of the imaging method according to the second embodiment, and Fig. 7 is a flow chart that shows the procedure of the imaging method according to the second embodiment. First, the ceramic material for the toilet is cut into a predetermined size, for example, 1 mm x 1 mm x 0.1 mm, to prepare a sample piece. The surface of this sample piece is polished with an abrasive until it becomes a mirror surface (step S31).

[0038] The sample piece is washed with pure water and then dried (step S32).

[0039] An aqueous solution of calcium carbonate is dropped evenly onto the surface of the test piece, and the test piece is dried at room temperature in a desiccator or the like, and this is used as a measurement sample (step S33).

[0040] Next, as shown in FIG. 6(a), the measurement sample 52 is fixed to the sample stage 51 of an atomic force microscope (high-speed AFM) using an adhesive such as nail polish (step S34).

[0041] The above-mentioned steps S31 to S34 are preparation steps in which an aqueous solution containing dirt components (calcium carbonate aqueous solution) is dropped onto a sample piece of an object (pottery) to be tested for reaction with a UFB solution (liquid), and the sample piece is dried to prepare a measurement sample. Step S31 is a polishing step for polishing the sample piece, and step S32 is a cleaning step for cleaning the polished sample piece. Step S33 is a dirt component attachment step in which an aqueous solution containing dirt components is dropped onto the surface of the cleaned sample piece to prepare a measurement sample.

[0042] 6(b), the UFB solution is dropped onto the surface of the measurement sample 52 using a pipette or the like to form droplets 53a, and air bubbles are soft-landed on the surface (step S35). Step S35 is a dropping process in which the UFB solution is dropped onto the surface of the measurement sample to adhere the UFB solution to the measurement sample, and air bubbles are soft-landed on the surface of the measurement sample.

[0043] Thereafter, as shown in Fig. 6(c), a sample stage 51 is fixed to a sample stage 32 of a high-speed AFM scanner 31 with nail polish or the like. Furthermore, as shown in Fig. 6(d), a UFB solution 53 is poured into a depression 33a formed in an observation solution cell 33 (step S36), and the surface of the high-speed AFM scanner 31 is oriented obliquely downward to immerse the droplet 53a in the UFB solution 53. Furthermore, the surface of the measurement sample 52 is made to face a probe 102a of a cantilever 102 mounted on an atomic force microscope.

[0044] In this state, the high-speed AFM scanner 31 is driven to scan the surface of the measurement sample 52 with the cantilever 102 (step S37). For example, scanning is performed at a speed of 0.5 fps (1 frame per 2 seconds).

[0045] The above-mentioned steps S36 and S37 are scanning processes in which the measurement sample with the UFB solution attached is immersed in a cell into which the UFB solution has been inserted, and the cantilever of the atomic force microscope is driven to scan the air bubbles that have soft-landed on the surface of the measurement sample.

[0046] The probe 102a of the cantilever 102 is displaced along the air bubble present on the surface of the measurement sample 52. Therefore, the air bubble can be imaged by the atomic force microscope 100 (step S38). Step S38 is an imaging step of imaging the air bubble based on the scanning data acquired in the scanning step.

[0047] The size, concentration, distribution, and behavior of the bubbles are then measured based on the image of the bubbles. If the bubbles are spherical, the diameter of the bubbles can be measured.

[0048] In this way, the imaging method according to the second embodiment makes it possible to obtain various data such as the particle size, concentration, distribution, and behavior of bubbles contained in a UFB solution in a non-bulk state.

[0049] Furthermore, as video visualization continues, it will be possible to visualize in real time the process of using the UFB solution to clean limescale from the toilet bowl.

[0050] [Third embodiment] Next, a third embodiment of the present invention will be described. In the third embodiment, as in the first and second embodiments, images of bubbles contained in a UFB solution are obtained using the atomic force microscope 100 shown in FIG.

[0051] In the third embodiment, artificial skin is used as an example of an object that comes into contact with air bubbles in a UFB solution, and the processing procedure for cleaning a measurement sample simulating artificial skin and water stains attached to its surface with a UFB solution is described.

[0052] From the viewpoint of animal welfare, several types of in vitro cultured artificial skin have been developed as alternatives to animal testing. For example, the Bell-type artificial skin model, the THS-type artificial skin model, and the TRS-type artificial skin model have been developed. In the third embodiment, such artificial skin is used as a measurement sample.

[0053] 8 is a flowchart showing the processing procedure of the bubble imaging method according to the third embodiment. First, the artificial skin to be tested is cut into a sample piece having a size of, for example, 1 mm×1 mm×0.1 mm (step S51).

[0054] The measurement sample is fixed to a substrate such as cleaved HOPG (graphite) or mica with an adhesive, and this is used as the measurement sample (step S52).

[0055] Next, as shown in FIG. 6(a), the measurement sample 52 is fixed to the sample stage 51 of the atomic force microscope using an adhesive such as nail polish (step S53).

[0056] The above-mentioned steps S51 to S53 are preparation steps in which an aqueous solution containing dirt components (calcium carbonate aqueous solution) is dropped onto an object (artificial skin) to be tested for reaction with a UFB solution (liquid), and then dried to prepare a measurement sample.

[0057] 6(b), a pipette or the like is used to drip the UFB solution onto the surface of the measurement sample 52 to form droplets 53a, and air bubbles in the UFB solution are soft-landed on the surface (step S54). Step S54 is a dripping process in which the UFB solution is dripped onto the surface of the measurement sample to attach the UFB solution to the measurement sample, and air bubbles are soft-landed on the surface of the measurement sample.

[0058] Thereafter, as shown in Fig. 6(c), a sample stage 51 is fixed to a sample stage 32 of a high-speed AFM scanner 31 with nail polish or the like. Furthermore, as shown in Fig. 6(c), a UFB solution 53 is poured into a depression 33a formed in an observation solution cell 33 (step S55), and the surface of the high-speed AFM scanner 31 is oriented obliquely downward to immerse the droplet 53a in the UFB solution 53. Furthermore, the surface of the measurement sample 52 is made to face a probe 102a of a cantilever 102 mounted on an atomic force microscope.

[0059] In this state, the high-speed AFM scanner 31 is driven to scan the surface of the measurement sample 52 with the cantilever 102 (step S56). For example, scanning is performed at a speed of 0.5 fps (1 frame per 2 seconds).

[0060] The above-mentioned steps S55 and S56 are scanning processes in which the measurement sample with the UFB solution attached is immersed in a cell into which the UFB solution has been inserted, and the cantilever of the atomic force microscope is driven to scan the air bubbles that have soft-landed on the surface of the measurement sample.

[0061] The probe 102a of the cantilever 102 is displaced along the air bubble present on the surface of the measurement sample 52. Therefore, the air bubble can be imaged by the atomic force microscope 100 (step S57). Step S57 is an imaging step of imaging the air bubble based on the scan data acquired by the scanning step.

[0062] The size, concentration and distribution of the bubbles are then measured based on the image of the bubbles. If the bubbles are spherical, the diameter of the bubbles can be measured.

[0063] In this way, similar to the second embodiment described above, the third embodiment also makes it possible to obtain various data such as the particle size, concentration, and distribution of bubbles contained in a UFB solution in a non-bulk state.

[0064] Furthermore, as video visualization continues, it will be possible to visualize in real time the process of using the UFB solution to clean limescale off the artificial skin.

[0065] In addition to the above-mentioned toilet bowl and artificial skin, for example, a semiconductor substrate can be used as a measurement sample, and the UFB solution can be dropped onto the semiconductor substrate, and the state of the bubbles that form when the solution is dropped can be imaged to measure the particle size, concentration, distribution, etc. Therefore, by imaging with atomic force microscope 100 while UFB solution is being dropped onto the semiconductor substrate using a reflux device, the cleaning process of the semiconductor substrate can be observed in real time.

[0066] In this way, by using actual samples (ceramics, artificial skin, semiconductor substrates, etc.) or pseudo samples, the areas in which UFB solution contributes to various measurement samples can be observed in a non-bulk state, i.e., a state (condition) in which the bubbles in the UFB solution are exerting their effect, and various data such as bubble size, concentration, and distribution can be quantified.

[0067] In addition, the pseudo sample (interface) can be prepared by Langmuir-Blodgett film, physical and chemical film formation techniques, or biochemical film formation methods such as the IPS method.

[0068] Although the embodiment of the present invention has been described above, the description and drawings forming a part of this disclosure should not be understood as limiting the present invention. Various alternative embodiments, examples and operating techniques will become apparent to those skilled in the art from this disclosure. [Explanation of symbols]

[0069] 11 Sample stage 12 discs (mica discs) 21 APTES solution 22, 53 UFB solution (liquid) 22a droplet 23 Bubbles 31 High-speed AFM scanner 32 Sample Stage 33 Observation solution cell 51 Sample stage 52 Measurement samples (ceramics, artificial skin) 100 Atomic Force Microscope 102 Cantilever 102a probe 103 Optical Displacement Detector 104 Amplifier

Claims

1. A method for imaging air bubbles contained in a liquid, comprising the steps of: providing a disk having a positively charged surface; a dropping step of dropping the liquid containing bubbles onto the surface of the disk to form droplets; a scanning step of immersing the disk with the droplets attached thereto in a cell containing the liquid and driving a cantilever of an atomic force microscope to scan for bubbles present on the surface of the disk; an imaging step of imaging the air bubble based on the scan data acquired by the scanning step; A method for imaging air bubbles, comprising:

2. The preparation step includes: A positively charged solution is dropped onto a cleaved mica disk to positively charge the surface of the disk.

2. The method for imaging bubbles according to claim 1,

3. and removing the solution by spraying compressed air onto the mica disk after dropping a positive charge onto the mica disk.

3. The method for imaging air bubbles according to claim 2, further comprising:

4. The positively charged solution is an APTES (3-aminopropyltriethoxysilane) solution.

4. The method for imaging bubbles according to claim 2 or 3,

5. The scanning step includes driving the cantilever at a speed of 0.5 fps or more to scan the bubble. The method for imaging air bubbles according to any one of claims 1 to 4,

6. A method for imaging air bubbles contained in a liquid, comprising the steps of: a preparation step of fixing a measurement sample of an object to be tested for reaction with the liquid on a sample stage; a dropping step of dropping the liquid onto a surface of the measurement sample to cause the liquid to adhere to the measurement sample and soft-land the air bubbles on the surface of the measurement sample; a scanning step of immersing the measurement sample with the liquid attached thereto in a cell into which the liquid has been inserted, and driving a cantilever of an atomic force microscope to scan the air bubbles that have soft-landed on the surface of the measurement sample; an imaging step of imaging the air bubbles based on the scan data acquired in the scanning step; A method for imaging air bubbles, comprising:

7. The preparation step includes: a polishing step of polishing the sample piece of the object; a cleaning step of cleaning the polished sample piece with pure water; and a dirt component attachment step of dropping an aqueous solution containing dirt components onto the surface of the sample piece after cleaning to prepare a measurement sample. The method for imaging air bubbles according to claim 6 ,

8. The object is an object to be cleaned by the liquid, and the aqueous solution is an aqueous calcium carbonate solution for depositing water stains on the object to be cleaned. The method for imaging air bubbles according to claim 7, further comprising:

9. The bubble imaging method according to any one of claims 6 to 8, wherein the target object is a toilet bowl or artificial skin.

Images