An in-situ visualization rapid measurement method for measuring the gas dissolution rate

Abstract

The present invention discloses an in-situ visualization rapid measurement method for measuring the gas dissolution rate: horizontally place the test substrate into the box body; turn on the planar light source assembly and focus it on the microcavity of the test substrate; evacuate the inside of the highly transparent heat-resistant glass main box, and inject the test gas into the highly transparent heat-resistant glass main box through the gas injection assembly; inject the test liquid into the internal liquid box through the liquid injection assembly until the microcavity at the bottom of the test substrate is quickly flooded and bubbles are generated inside the microcavity; use a CCD camera and a data acquisition and recording system to observe and record in real time the generation and dissolution disappearance process of the bubbles inside the microcavity of the test substrate, record the time and images of the whole process, and calculate the dissolution rate of the gas in the liquid medium. In the case of a large machine vision recording range, the present invention realizes the measurement and monitoring of the air dissolution rate inside multiple microcavities through one measurement, obtains a large number of samples, and the obtained average result is accurate, avoiding the contingency of the experiment.

Description

Technical Field

[0001] The present invention belongs to the field of surface and interface chemical measurement, and particularly relates to an in-situ visualization rapid measurement method for measuring the gas dissolution rate. Background Art

[0002] The dissolution phenomenon of gas in the liquid interior is one of the common phenomena in industrial manufacturing and equipment use. There are also differences in the requirements or limitations for the gas dissolution rate according to different product application scenarios. Some manufacturing processes require maintaining the undissolved bubbles, while some hope to avoid generating bubbles or make the bubbles disappear as soon as possible, which is related to the gas dissolution rate in the liquid medium. For example, in the process of preparing porous foam composites, if the residual bubbles inside do not dissolve or escape as soon as possible, it is easy to form bubble defects during the subsequent curing process. At this time, it is hoped that the gas can dissolve in the medium as soon as possible to avoid forming bubbles in the product. However, in some other industrial fields, sometimes it is required that the bubbles can be maintained for a long time. For example, in ship underwater drag reduction, if there are more bubbles at the solid-liquid interface, the gas-liquid boundary in the bubble region will replace the solid-liquid boundary, generating boundary slip, which can reduce the underwater drag. In these processes, the measurement of the gas solubility in the medium is very crucial reference data. Exploring the dissolution rate of microbubbles can provide guidance and reference for the design and preparation of materials. However, currently, there are relatively few methods for measuring the gas dissolution rate. Most gas solubility measurement devices measure the saturated solubility by statically placing air in the liquid for a long time. Since the measurement time is often long and uncertain, it is difficult to obtain a reliable and quantitative gas dissolution rate. Summary of the Invention

[0003] The present invention designs an in-situ visualization rapid measurement method for measuring the gas dissolution rate, and realizes the convenient and rapid measurement of the gas dissolution rate in the liquid medium through an in-situ, rapid and multiple sampling measurement method.

[0004] The present invention proposes the following technical solutions to solve its technical problems

[0005] An in-situ visualization rapid measurement method for measuring the gas dissolution rate, which is based on an in-situ observation device for measuring the dissolution rate of trace gases in a liquid medium. The device includes an observation system 8 arranged at the upper part, a test substrate 7 arranged in the middle, and a planar light source assembly 1 arranged at the lower part; the planar light source assembly 1 provides a visual background illumination condition for the test substrate 7; the observation system 8 is used to record and save the measurement process in real time, adjust the focal length and magnification to make the image clearly visible; the test substrate 7 uses microcavities at the micron and millimeter levels as reaction chambers for testing the gas dissolution rate, and is made into a transparent test substrate, with optical photo detection as the main testing method; a highly transparent heat-resistant glass main box 6 that surrounds it is also arranged outside the test substrate 7. The test substrate 7 is horizontally mounted on the inner box body of the highly transparent heat-resistant glass main box 6. The highly transparent heat-resistant glass main box 6 provides an external carrier for enclosing, pressurizing, temperature control, and liquid holding during the measurement process; on the outer box body of the highly transparent heat-resistant glass main box 6, there are also a liquid injection assembly 2, a gas pressure and temperature monitoring assembly 4, and a gas injection assembly 5; temperature heating assemblies 3 are also respectively arranged on the inner box body of the highly transparent heat-resistant glass main box 6 and on the liquid injection assembly 2; the liquid injection assembly 2 provides liquid filling for the measurement process of the test substrate 7 and submerges the test substrate 7; the temperature heating assembly 3 provides a stable and reliable ambient temperature for measuring the dissolution rate at different temperatures; the gas pressure and temperature monitoring assembly 4 monitors the changes in gas pressure and temperature during the measurement process, and feeds back to the temperature heating assembly 3 at any time and feeds back to the gas injection assembly 5 at any time; the gas injection assembly 5 provides test gas for the measurement process and controls the reaction pressure.

[0006] It is characterized in that: the method includes the following steps:

[0007] It is characterized in that: the method includes the following steps:

[0008] Step 1: Place the test substrate 7 into the box body and firmly fix it horizontally with the sample clamp 63;

[0009] Step 2: Turn on the planar light source assembly 1 and adjust the light intensity, and adjust the CCD camera 81 so that it focuses on the microcavity of the test substrate 7; the volume of a single microcavity in the microcavity sample is very small, and the size can be controlled from a few microns to a few millimeters, which can meet the measurement requirements of different two-phase media. The volume of the reaction microcavity with a small size can be controlled at the order of 10 -18 m 3 quantity level;

[0010] Step 3: Evacuate the inside of the highly transparent heat-resistant glass main box 6, and then inject the test gas into the highly transparent heat-resistant glass main box 6 through the gas injection assembly 5. Use the gas pressure and temperature monitoring assembly 4 to monitor the gas pressure inside the box body and adjust the gas pressure and temperature through the gas injection assembly 5 and the temperature heating module 3;

[0011] Step 4: Inject the test liquid into the internal liquid tank 62 through the liquid injection assembly 2 until the microcavity at the bottom of the test substrate 7 is quickly flooded. At this time, air bubbles are generated inside the microcavity.

[0012] Step 5: Use the CCD camera 81 and the data acquisition and recording system 82 to observe and record the generation and dissolution process of air bubbles inside the microcavity of the test substrate (7) in real time, record the time and images of the whole process, and calculate the dissolution rate of gas in the liquid medium.

[0013] Step 6: After the test, first balance the internal and external air pressures using the air vent valve 54, extract the liquid from the box using the liquid injector 22, open the external sealed box 61 to take out the test substrate 7, wash it for recycling, and clean the inside of the highly transparent heat-resistant glass main box 6 for the next use.

[0014] Further, putting the test substrate 7 into the box in Step 1 is specifically as follows:

[0015] After the test substrate 7 is installed, the microcavity sample surface remains in a horizontal state, which is convenient for ensuring that when the liquid level approaches the microcavity at the bottom of the test substrate 7 during the process of injecting the test liquid into the internal liquid tank 62 through the liquid injection assembly 2 in Step 4, the microcavity array for testing can be covered by the liquid medium as much as possible at the same time.

[0016] Further, injecting the test gas into the highly transparent heat-resistant glass main box 6 through the gas injection assembly 5 in Step 3 is specifically as follows: The pressure valve 53 of the gas injection assembly 5 is opened when ventilating the external sealed box 61 and the internal liquid tank 62 of the highly transparent heat-resistant glass main box 6, and is closed before injecting liquid into the internal liquid tank 62; The air vent valve 54 of the gas injection assembly 5 has two functions: evacuating and adjusting the air pressure; it is connected to the vacuum pump when evacuating, discharges the gas when adjusting the air pressure, and is closed at other times.

[0017] Further, injecting the test liquid into the internal liquid tank 62 through the liquid injection assembly 2 until the microcavity at the bottom of the test substrate 7 is quickly flooded. At this time, air bubbles are generated inside the microcavity in Step 4.

[0018] The specific process is as follows:

[0019] 1) Before the test, place the test liquid in a vacuum drying oven in advance for degassing, and draw the bottom layer of the liquid into the syringe 22 for standby before liquid injection.

[0020] 2) When injecting liquid, turn on the CCD camera 81 and the data acquisition and recording system 82 before air bubbles are generated on the test substrate 7 to record the complete process from bubble generation to disappearance.

[0021] 3) When the liquid level approaches the microcavity at the bottom of the test substrate 7, the liquid injection should be accelerated to make the liquid level rise rapidly, ensuring that the microcavity array for testing can be covered by the liquid medium as much as possible at the same time;

[0022] 4) When the liquid injection assembly 2 injects into the internal liquid tank 62 until it quickly submerges the microcavity at the bottom of the test substrate 7, bubbles are generated inside the microcavity at this time;

[0023] 5) The liquid injection stops when the liquid is higher than the bottom of the air pressure balance through hole 64 between the inner and outer boxes.

[0024] Furthermore, the test liquid is required to be able to transmit light and be free of impurities, and the light transmittance of the test liquid, the light transmittance of the external sealed box 61 and the internal liquid tank 62, the light transmittance of the test liquid, and the light transmittance of the test substrate 7 match, and the light transmittance is above 90%.

[0025] Furthermore, in step five, the generation and dissolution disappearance process of the bubbles inside the microcavity of the test substrate 7 is observed and recorded in real time. This disappearance process is the entire process from the appearance of the bubbles to the complete disappearance of the bubbles.

[0026] Specifically as follows:

[0027] 1) In the initial state, the black edge circle of the microcavity is the boundary of the bubble;

[0028] 2) As the gas dissolves, this black circle gradually becomes smaller;

[0029] 3) This black circle completely disappears, and at this time the gas inside the microcavity has completely dissolved.

[0030] Furthermore, in step five, the dissolution rate of the gas in the liquid medium is calculated, specifically as follows:

[0031] 1) According to the state equation of ideal gas: where n is the number of moles of gas (unit: mol), P is the pressure of the gas (unit: Pa), V is the volume of the gas (unit: m 3 ), R is the molar gas constant, R = 8.314 J·mol -1 ·K -1 , and T is the thermodynamic temperature (unit: K). The dissolution rate of the gas in the liquid medium under constant temperature and pressure is where V 腔 is the internal volume of a single microcavity; P and T are measured values, P is provided by the pressure gauge 41, and T is provided by the temperature sensor 43; t is the dissolution time of the gas inside a single microcavity, that is, the time taken for the entire process from the appearance of the bubbles to the complete disappearance of the bubbles.

[0032] 2) Select at least 5 microcavities at different positions in the recorded image, calculate the gas dissolution rate inside each single microcavity, and then take the average value as the measured value of the gas dissolution rate in the liquid. The standard deviation of multiple measurements is used as the error value.

[0033] Further, the test substrate 7 is provided with uniformly arranged microcavities for chemical reactions. Each microcavity only opens on one side of the test substrate 7 facing the planar light source assembly 1, and this opening serves as the reaction cavity for the internal gas and the test liquid. Each uniformly arranged microcavity does not penetrate inside the test substrate 7; the internal gas volume of a single microcavity can be measured.

[0034] Further, the shape of the microcavity includes square or circular, and the characteristic dimension at its opening is such that when a specific liquid enters the microcavity, it is not significantly disturbed at the opening edge; the opening depth h of the microcavity is less than or equal to the shortest side length or diameter at the opening of the microcavity for the current specific liquid; the spacing L between microcavities is not less than the shortest side length or diameter at the opening of the microcavity for the current specific liquid.

[0035] Advantages and Effects of the Invention

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] 1) The measurement method of the present invention is simple, the device is simple, and the principle is simple. Even theoretically, test data can be obtained only by visually recording the measurement process. However, for accuracy, the present invention uses machine vision to record the detection process.

[0038] 2) The gas-liquid two-phase reaction medium of the present invention is a microcavity substrate. The volume of the microcavities in the microcavity substrate is controllable and the standardization degree is high, which can ensure that the dissolution reactions inside each microcavity are carried out under the same conditions. In the case of a large machine vision recording range, the measurement and monitoring of the air dissolution rate inside multiple microcavities can be achieved through one measurement. The number of samples obtained is large, and the average result obtained is accurate, avoiding the contingency of the experiment.

[0039] 3) The volume of a single microcavity in the microcavity sample adopted by the present invention is very small, and the size can be controlled from a few micrometers to a few centimeters, which can meet the measurement requirements of different two-phase media. The volume of the reaction microcavity with a small size can be controlled at the order of 10 - 13 m3, and the reaction speed is faster than that of a large-volume reaction cavity. The measurement time is short, and the measurement of the air dissolution rate is more accurate. Description of the Drawings

[0040] Figure 1 It is the functional block diagram of the in-situ observation device of the present invention;

[0041] Figure 2 It is the layout diagram of the in-situ observation device of the present invention;

[0042] Figure 3a Schematic diagram of the square-hole microcavity of the gas test substrate of the present invention;

[0043] Figure 3b Schematic diagram of the round-hole microcavity of the gas test substrate of the present invention;

[0044] Figure 3c Cross-sectional view of the square-hole microcavity of the gas test substrate of the present invention;

[0045] Figure 4 Schematic diagram of the change of air bubbles in the microcavity of the present invention.

[0046] Figure 5 Flow chart of the in-situ visualization rapid measurement method for measuring the gas dissolution rate of the present invention.

[0047] In the figure, 1: planar light source assembly; 11: aluminum substrate; 12: light source brightness regulator; 2: liquid injection assembly; 21: liquid guide tube; 22: syringe; 3: temperature heating device assembly; 31: heater block; 32: temperature control module; 33: heater block; 34: connecting wire; 4: air pressure and temperature monitoring assembly; 41: gas pressure gauge; 42: temperature sensor; 43: temperature sensor; 5: gas injection assembly; 51: gas storage cylinder; 52: gas conduit; 53: air pressure valve; 54: air release valve; 6: highly transparent heat-resistant glass main box; 61: external sealing box; 62: internal liquid box; 63: sample clamp; 64: air pressure balance through hole between the inner and outer boxes; 7: test substrate; 8: observation system; 81: CCD camera; 82: data acquisition and recording system. Specific implementation mode

[0048] 1. Innovation point of the present invention: Using microcavities at the micron and millimeter levels as reaction chambers for testing the gas dissolution rate, replacing the traditional large-volume reaction kettle-type measurement device, making the measurement reaction very rapid.

[0049] 2. Design difficulty of the present invention: The difficulty lies in how to inject the test liquid into the micron-level microcavity with a diameter as thin as a hair and use the test liquid to test the gas dissolution rate; the difficulty also lies in that the viscosity of the injected test liquid is often higher than that of water.

[0050]

[0051] ​3. Design principle of the micro-meter level reaction chamber: The method for injecting test liquid into the micro-meter level reaction chamber in the present invention is as follows: First, evacuate the micro-chamber; second, inject gas into the micro-chamber, and this gas is various gases to be tested. Although the micro-chamber is at the micro-meter level, in a vacuum environment, due to the pressure difference between the gas to be tested and the micro-chamber, the gas to be tested can be introduced into the micro-chamber. Third, inject test liquid into the micro-chamber filled with the gas to be tested. The method for injecting test liquid into the micro-chamber in the present invention is not an active injection method, but a method of "dissolving". The method of "dissolving" is a method of interaction between the molecules of two different media (the gas to be tested and the test liquid). Even a micro-chamber at the micro-meter level can fully accommodate molecules and will not prevent the interaction between molecules. Specifically: When the liquid level of the test liquid approaches the micro-chamber at the bottom of the test sample 7, accelerate the liquid injection to make the liquid level rise rapidly, ensuring that the micro-chamber array can be covered by the liquid medium as much as possible at the same time; when the gas in the micro-chamber is covered by the test liquid medium, the gas inside the micro-chamber will quickly dissolve into the liquid. The phenomenon observed from a visual angle is that the bubbles in each micro-chamber change from large to small. As the bubbles in the micro-chamber gradually become smaller, the test liquid "squeezes in" around the bubbles. When the gas to be tested in the micro-chamber is completely dissolved, only the test liquid remains in the micro-chamber. In short, the method for testing the gas dissolution rate in the present invention is to "dissolve" the gas in the micro-chamber into the liquid. The method of "dissolving" is a method of dividing into the smallest units; the method of dividing into the smallest units is a method with molecules as the smallest units. Thus, the technical problem that it is difficult to pour viscous liquid into a micro-chamber at the micro-meter level is solved.

[0052] 4. Solution of the present invention: Focusing on the test of the gas to be measured in the micro-chamber, the present invention organically combines several parts including the planar light source assembly 1, the liquid injection assembly 2, the gas injection assembly 5, the highly transparent heat-resistant glass main box 6, and the observation system 8. These five parts support and depend on each other:

[0053] The LED array of the planar light source assembly 1 is covered with a diffuser plate, providing a backlight illumination environment with uniform light, adjustable brightness, constant contrast, and no light-emitting shadow for the test substrate 7. The maximum illuminance is not less than 20000 lux. If the above conditions are not met, the light provided for the test substrate 7 is not uniform enough, or the contrast cannot be kept constant, then the state capture of the bubbles from generation to disappearance is inaccurate, and the time t from the generation to the disappearance of the bubbles is also calculated inaccurately.

[0054] When the liquid level of the liquid injection assembly 2 approaches the microchamber at the bottom of the test sample 7, the liquid injection assembly 2 should accelerate the liquid injection to rapidly raise the liquid level, ensuring that the microchamber array for testing can be covered by the liquid medium as much as possible at the same time; without the above conditions, the contact time between the gas and the liquid level in different microchambers will be different, and the generation and disappearance times of the bubbles will be uneven, and the average value t cannot be accurately calculated.

[0055] The gas injection assembly 5 is used to inflate the outer box and the inner box of the highly transparent heat-resistant glass main box 6 (the gas to be tested), and always maintain the pressure balance between the inner and outer boxes through the air pressure balance through hole 64 of the inner and outer boxes. The purpose of maintaining the pressure balance is as follows: when the microchamber contacts the test liquid, as the gas to be tested in the microchamber dissolves in the test liquid, the gas in the microchamber becomes less and the gas pressure in the microchamber also becomes smaller. Since the inner box and the outer box are always pressure-balanced, and because the volume of the microchamber accounts for a very small proportion compared to the volume of the inner box, when the internal pressure of the microchamber becomes smaller, the overall pressure of the inner box does not change and remains pressure-balanced with the outer box. At this time, a pressure difference is formed between the microchamber and the test liquid in the inner box. This pressure difference makes it easier for the test liquid to "squeeze into" the microchamber while dissolving the gas in the microchamber. Without the above conditions, the gas injection assembly 5 cannot inject the gas to be tested into the inner and outer boxes, and there is no pressure difference between the test liquid and the microchamber, so the test liquid cannot obtain pressure and is not easy to "squeeze into" the surrounding of the bubble, and the bubble is not easy to be dissolved until it disappears without the liquid around it.

[0056] The highly transparent heat-resistant glass main box 6 is provided with an external sealed box 61, an internal liquid box 62, a sample clamp 63, and an air pressure balance through hole 64 between the inner and outer boxes; the purpose of setting the external box is to add a protective layer to the microchamber to prevent other impurity gases from mixing in and affecting the purity of the gas to be tested. The air pressure balance through hole 64 between the inner and outer boxes is used to balance the pressure between the inner box and the outer box when injecting gas. This pressure balance enables the inner box to maintain the same pressure as the outer box when the gas in the microchamber is gradually dissolved and the pressure in the microchamber becomes smaller, or a pressure difference is formed between the test liquid in the inner box and the microchamber. Without the above conditions, the air pressure balance through hole 64 between the inner and outer boxes cannot maintain the pressure balance between the inner and outer boxes. When the gas in the microchamber is gradually dissolved, the test liquid cannot obtain pressure and is not easy to "squeeze into" the surrounding of the bubble, and the bubble is not easy to be dissolved until it disappears without the liquid around it.

[0057] The observation system 8 is configured with a CCD camera 81 equipped with a magnifying lens and a data acquisition and recording system 82. There are three requirements for the observation system to measure the dissolution rate of the test gas. First, the CCD camera 81 should be able to achieve an image acquisition speed of at least 50 fps. Second, the data recording and storage speed of the data acquisition and recording system 82 should be higher than the image acquisition speed of the CCD camera 81. Third, according to the size of a single microcavity of the test substrate 7, its magnification is adjustable and the focal length is variable. Without the above conditions, if the acquisition speed of the camera does not match or the storage speed of the camera is less than the image acquisition speed, even if the camera captures the process of bubble change in time, calculation errors will occur due to storage lag. If the magnification and focal length of the camera cannot be adjusted according to the size of a single microcavity, accurate calculation cannot be completed either.

[0058] In summary, the above five components, namely the planar light source assembly 1, the liquid injection assembly 2, the gas injection assembly 5, the highly transparent heat-resistant glass main box 6, and the observation system 8, complement each other and are interdependent to finally complete the measurement of the gas dissolution rate.

[0059] 5. The in-situ visualization rapid measurement device for measuring the gas dissolution rate of the present invention. The device includes an observation system 8 arranged at the upper part, a test substrate 7 arranged in the middle, and a planar light source assembly 1 arranged at the lower part. The planar light source assembly 1 provides a visual background illumination condition for the test substrate 7. The observation system 8 is used to record and save the measurement process in real time, adjust the focal length and magnification to make the image clearly visible. The test substrate 7 uses microcavities at the micron and millimeter levels as reaction chambers for testing the gas dissolution rate, and is made into a transparent test substrate, with optical photo detection as the main test method. A highly transparent heat-resistant glass main box 6 that surrounds the test substrate 7 is also provided outside the test substrate 7. The test substrate 7 is horizontally mounted on the inner box body of the highly transparent heat-resistant glass main box 6. The highly transparent heat-resistant glass main box 6 provides an external carrier for enclosing, pressurizing, temperature control, and liquid holding during the measurement process. On the outer box body of the highly transparent heat-resistant glass main box 6, there are also a liquid injection assembly 2, a gas pressure and temperature monitoring assembly 4, and a gas injection assembly 5. Temperature heating assemblies 3 are respectively provided on the inner box body of the highly transparent heat-resistant glass main box 6 and on the liquid injection assembly 2. The liquid injection assembly 2 provides liquid injection for the measurement process of the test substrate 7 and submerges the test substrate 7. The temperature heating assembly 3 provides a stable and reliable ambient temperature for measuring the dissolution rate at different temperatures. The gas pressure and temperature monitoring assembly 4 monitors the changes in gas pressure and temperature during the measurement process and feeds back to the temperature heating assembly 3 and the gas injection assembly 5 at any time. The gas injection assembly 5 provides test gas for the measurement process and controls the reaction pressure.

[0060] Furthermore, the test substrate 7 is provided with uniformly arranged microcavities for gas dissolution reaction. Each microcavity has an opening only on one side facing the planar light source assembly 1 on the test substrate 7, and this opening serves as the reaction chamber for the internal gas and the test liquid. Each uniformly arranged microcavity does not penetrate inside the test substrate 7; the amount of internal gas in a single microcavity can be measured.

[0061] Furthermore, the shape of the microcavity includes but is not limited to square or circular, and the characteristic dimension at the opening is such that when a specific liquid enters the microcavity, it is not significantly disturbed at the opening edge; the depth h of the microcavity opening is less than or equal to the shortest side length or diameter at the microcavity opening for the current specific liquid; the spacing L between microcavities is not less than the shortest side length or diameter at the microcavity opening for the current specific liquid.

[0062] Furthermore, the size of the microcavity is between 1 μm and 10 mm, and the volume of the reaction microcavity with a small size can be minimized to the order of 10 -18 m 3 quantity level.

[0063] Furthermore, the test substrate 7 is prepared by photolithography processing or precision machining, and the materials selected according to the temperature requirements of the test include but are not limited to high-transmission heat-resistant quartz glass and polydimethylsiloxane.

[0064] Furthermore, the observation system 8 is configured with a CCD camera 81 with a magnifying lens and a data acquisition and recording system 82; the CCD camera 81 can achieve an image acquisition speed of at least 50 fps; the data recording and storage speed of the data acquisition and recording system 82 is higher than the image acquisition speed of the CCD camera 81; the CCD camera (81) can be selected with a magnifying lens more than twice, and according to the size of a single microcavity of the test substrate 7, its magnification is adjustable and the focal length is variable.

[0065] Furthermore, the planar light source assembly 1 includes an aluminum substrate 11 for bearing the carrier, a light source brightness regulator 12 for adjusting the light source brightness of the LED planar light source body 13, and an LED planar light source body 13 for providing a visual background illumination condition for the test substrate 7; the size of the light-emitting area in the LED planar light source body 13 is larger than the cross-sectional size of the internal liquid tank 62 parallel to it, and a diffuser plate is covered on the LED array to provide a backlight illumination environment with uniform light, adjustable brightness, constant contrast, and no light-emitting shadow for the test substrate 7, and the maximum illuminance is not less than 20000 lux.

[0066] Further, the liquid injection assembly 2 includes a liquid guide tube 21 and a syringe 22. The upper end of the liquid guide tube 21 is connected to the syringe 22, and the lower end leads to the lower surface of the inner wall of the highly transparent heat-resistant glass main body box 6. The syringe 22 provides liquid injection for the test substrate 7 through the liquid guide tube 21 until the liquid submerges the test substrate 7. When the liquid level approaches the microcavity at the bottom of the test sample 7, the liquid injection assembly 2 needs to accelerate the liquid injection to quickly raise the liquid level, ensuring that the microcavity array for testing can be covered by the liquid medium as much as possible at the same time. The volume of the syringe 22 needs to be greater than the volume of the inner liquid box 62 of the highly transparent heat-resistant glass main body box 6.

[0067] Further, the highly transparent heat-resistant glass main body box 6 is provided with an external sealing box 61, an inner liquid box 62, a sample clamp 63, and an air pressure balance through hole 64 between the inner and outer boxes. The external sealing box 61 is used to store gas, and the inner liquid box 62 is used to store liquid. The air pressure balance through hole 64 between the inner and outer boxes is used to balance the internal and external air pressures during the liquid injection process, ensuring that the gas in the inner box is not compressed during the liquid injection process. The height of the air pressure balance through hole 64 between the inner and outer boxes needs to be higher than the upper surface of the inner liquid box 62, which can indicate the completion of liquid injection into the inner liquid box 62.

[0068] Further, the light transmittance of the highly transparent heat-resistant glass external sealing box 61 and the inner liquid box 62, the light transmittance of the test liquid, and the light transmittance of the test substrate 7 are matched, and the light transmittance is above 90%. The test substrate 7 is made of a light-transmitting material, including but not limited to acrylic, glass, PDMS, resin, as long as it is a light-transmitting material that can be processed into a microcavity.

[0069] Further, the gas injection assembly 5 includes a pressure valve 53 and a ventilation valve 54. The pressure valve 53 is opened when ventilating the external sealing box 61 and the inner liquid box 62 of the highly transparent heat-resistant glass main body box 6, and is closed before injecting liquid into the inner liquid box 62. The ventilation valve 54 of the gas injection assembly 5 has two functions: vacuum pumping and pressure adjustment. When pumping vacuum, it is connected to a vacuum pump, and when adjusting the pressure, it discharges gas and is closed at other times.

[0070] Based on the above invention principle and device, the present invention designs an in-situ visualization rapid measurement method for measuring the gas dissolution rate.

[0071] An in-situ visualization rapid measurement method for measuring the gas dissolution rate is as Figure 5 shown. This method is based on an in-situ observation device for measuring the dissolution rate of trace gases in a liquid medium as Figure 1 、 Figure 2 、 Figure 3a 、 Figure 3b 、 Figure 3c 、 Figure 4As shown in the figure, the device includes an observation system 8 arranged at the upper part, a test substrate 7 arranged in the middle, and a planar light source assembly 1 arranged at the lower part; the planar light source assembly 1 provides a visual background illumination condition for the test substrate 7; the observation system 8 is used to record and save the measurement process in real time, adjust the focal length and magnification to make the image clearly visible; the test substrate 7 uses microcavities at the micron and millimeter levels as reaction chambers for testing the gas dissolution rate, and is made into a transparent test substrate, with optical photo detection as the main testing method; a highly transparent heat-resistant glass main box 6 that surrounds the test substrate 7 is also provided outside the test substrate 7. The test substrate 7 is horizontally mounted on the inner box body of the highly transparent heat-resistant glass main box 6. The highly transparent heat-resistant glass main box 6 provides an external carrier for enclosing, pressurizing, temperature controlling, and liquid containing for the measurement process; on the outer box body of the highly transparent heat-resistant glass main box 6, a liquid injection assembly 2, a gas pressure and temperature monitoring assembly 4, and a gas injection assembly 5 are also provided; temperature heating assemblies 3 are also respectively provided on the inner box body of the highly transparent heat-resistant glass main box 6 and on the liquid injection assembly 2; the liquid injection assembly 2 provides liquid injection for the measurement process of the test substrate 7 and submerges the test substrate 7; the temperature heating assembly 3 provides a stable and reliable ambient temperature for measuring the dissolution rate at different temperatures; the gas pressure and temperature monitoring assembly 4 monitors the changes in gas pressure and temperature during the measurement process, and feeds back to the temperature heating assembly 3 at any time and feeds back to the gas injection assembly 5 at any time; the gas injection assembly 5 provides test gas for the measurement process and controls the reaction pressure.

[0072] Supplementary Note 1 :

[0073] 1. As Figure 2 shown, the light transmittance of the inner and outer box bodies of the highly transparent heat-resistant glass box is greater than 90%. The size is from 5 cm × 5 cm × 2 cm to 10 cm × 10 cm × 5 cm. The gas exchange between the external sealed box 61 and the outside is carried out through a gas pressure valve 53 and a ventilation valve 54. The internal liquid box 62 is smaller than the external sealed box 61, and the material is also highly transparent heat-resistant glass. The sample clamp 63 is required to have a maximum heat resistance of not less than 300 °C and be elastic. Its function is to apply a certain pressing force to the sample to prevent the sample from moving. The air pressure balance through hole 64 between the inner and outer box bodies is located at the upper end of the inner box body, and its function is to keep the gas connection and air pressure balance between the inner and outer box bodies, and there is no requirement for its size. The highly transparent heat-resistant glass external sealed box 61 can be completely sealed and not opened for use as a disposable detection box, or it can be made with an openable upper cover for multiple uses, but it must be kept sealed during use. The internal liquid box 62 is fixedly connected to the bottom of the external sealed box 61.

[0074] 2. As Figure 2As shown in the figure, the temperature heating device assembly 3 includes heater blocks 31 and 33, a temperature control module 32, and connecting wires 34; the heater assembly 31 wraps the liquid injection tube 21 to provide real-time heating for the test liquid, and the temperature control module 32 and the heater block 31 have an adjustment range of 25°C to 300°C.

[0075] 3. As Figure 2 shown in the figure, the air pressure and temperature monitoring assembly 4 includes a gas pressure gauge 41, temperature sensors 42 and 43. The gas pressure gauge 41 is installed on the outer box body 61 of the transparent heat-resistant glass box to measure the real-time air pressure inside the test box body 61, and the connection is sealed. The temperature sensor 42 is installed on the box body 61 of the transparent heat-resistant glass box and penetrates through the heat-resistant glass box 62 to measure the temperature inside the heat-resistant glass box 62; the temperature sensor 43 is installed on the outer box body 61 of the transparent heat-resistant glass box to measure the gas temperature between the transparent heat-resistant glass boxes 61 and 62. (This assembly is a commonly used component in the market)

[0076] 4. The gas storage cylinder 51 is connected to the external sealed box 61 at the air pressure valve 53 through a gas conduit 52, and the connection is sealed, and the injected gas pressure can be adjusted through the air pressure valve 53, and there is no requirement for the size of the gas storage cylinder; the ventilation valve 54 is connected to the outside of the external sealed box 61, and the connection is sealed, and it is used for deflation and pressure adjustment when the internal air pressure of the external sealed box 61 does not meet the requirements.

[0077] It is characterized in that: the method includes the following steps:

[0078] Step 1: Place the test substrate 7 into the box body and firmly fix it horizontally using the sample clamp 63;

[0079] Step 2: Turn on the planar light source assembly 1 and adjust the light intensity, and adjust the CCD camera 81 so that it focuses on the microcavity of the test substrate 7; the volume of a single microcavity in the microcavity sample is very small, and the size can be controlled from a few micrometers to a few millimeters, which can meet the measurement requirements of different two-phase media, and the volume of the reaction microcavity with a small size can be controlled at the order of magnitude of 10 -18 m 3 quantity level;

[0080] Step 3: Evacuate the high-transparency heat-resistant glass main box 6, and then inject the test gas into the high-transparency heat-resistant glass main box 6 through the gas injection assembly 5, and use the air pressure and temperature monitoring assembly 4 to monitor the internal air pressure of the box body and adjust the air pressure and temperature through the gas injection assembly 5 and the temperature heating module 3;

[0081] Supplementary Note 3:

[0082] 1. In a preferred embodiment of the present invention, the degree of vacuum is maintained at about 0.1 MPa when evacuating in Step 3 of the device.

[0083] 2. In a preferred embodiment of the present invention, the pressure error of the pressure gauge 41 is within ±0.1 MPa, and the errors of the temperature sensors 42 and 43 are within ±0.1 °C.

[0084] 3. In a preferred embodiment of the present invention, the valve devices on the main box body 61 are all multi-gas-sealed using soft silicon wafers, and the ventilation valve 64 on the box body 62 penetrates through the box bodies 61 and 62.

[0085] Step Four: Inject the test liquid into the internal liquid box 62 through the liquid injection assembly 2 until the micro-cavity at the bottom of the test substrate 7 is quickly submerged. At this time, bubbles are generated inside the micro-cavity.

[0086] Supplementary Note 4:

[0087] As Figure 4 shown, when the bubbles are just generated, they fill the entire micro-cavity. As the gas in the bubbles dissolves in the test liquid, the bubbles become smaller and shrink from the boundary, as shown by the bubbles on the right side in Figure 4 the figure.

[0088] Step Five: Use the CCD camera 81 and the data acquisition and recording system 82 to observe and record in real time the generation, dissolution, and disappearance process of the bubbles inside the micro-cavity of the test substrate (7), record the time and images of the entire process, and calculate the dissolution rate of the gas in the liquid medium.

[0089] Step Six: After the test is completed, first use the ventilation valve 54 to balance the internal and external air pressures, use the liquid injector 22 to pump the liquid out of the box, open the external sealed box 61 to take out the test substrate 7, wash it for recycling, and clean the inside of the highly transparent heat-resistant glass main box 6 for the next use.

[0090] Further, the step of placing the test substrate 7 into the box in Step One is specifically:

[0091] After the test substrate 7 is installed, the micro-cavity sample surface remains in a horizontal state, which is convenient for ensuring that when the test liquid is injected into the internal liquid box 62 through the liquid injection assembly 2 in Step Four and the liquid level approaches the micro-cavity at the bottom of the test substrate 7, the micro-cavity array for testing can be covered by the liquid medium as much as possible at the same time.

[0092] Further, the step of injecting the test gas into the highly transparent heat-resistant glass main box 6 through the gas injection assembly 5 in Step Three is specifically: The pressure valve 53 of the gas injection assembly 5 is opened when ventilating the external sealed box 61 and the internal liquid box 62 of the highly transparent heat-resistant glass main box 6, and is closed before injecting liquid into the internal liquid box 62; the ventilation valve 54 of the gas injection assembly 5 has two functions: evacuating the vacuum and adjusting the air pressure; when evacuating the vacuum, it is connected to the vacuum pump, when adjusting the air pressure, it discharges the gas, and is closed at other times.

[0093] Further, in Step 4, the test liquid is injected into the internal liquid tank 62 through the liquid injection assembly 2 until the microcavities at the bottom of the test substrate 7 are quickly flooded. At this time, bubbles are generated inside the microcavities;

[0094] The specific process is as follows:

[0095] 1) Before the test, the test liquid is placed in a vacuum drying oven in advance for degassing, and the bottom layer liquid is pumped into the syringe 22 for standby before liquid injection;

[0096] 2) When injecting liquid, the CCD camera 81 and the data acquisition and recording system 82 are turned on before bubbles are generated on the test substrate 7 to record the complete process from bubble generation to disappearance;

[0097] 3) When the liquid level approaches the microcavities at the bottom of the test substrate 7, the liquid injection speed should be increased to make the liquid level rise rapidly, ensuring that the microcavity array for testing can be covered by the liquid medium as much as possible at the same time;

[0098] 4) When the liquid injection assembly 2 injects into the internal liquid tank 62 until the microcavities at the bottom of the test substrate 7 are quickly flooded, bubbles are generated inside the microcavities at this time;

[0099] 5) When the liquid is higher than the bottom of the air pressure balance through hole 64 between the inner and outer boxes, the liquid injection stops.

[0100] Further, the test liquid is required to be able to transmit light and be free of impurities, and the light transmittance of the test liquid, the light transmittance of the external sealed box 61 and the internal liquid tank 62, the light transmittance of the test liquid, and the light transmittance of the test substrate 7 match, and the light transmittance is above 90%.

[0101] Further, in Step 5, the generation and dissolution and disappearance process of the bubbles inside the microcavities of the test substrate 7 are observed and recorded in real time. This disappearance process is the entire process from the appearance of the bubbles to the complete disappearance of the bubbles.

[0102] Specifically as follows:

[0103] 1) In the initial state, the black edge circle of the microcavity is the boundary of the bubble;

[0104] 2) As the gas dissolves, the black circle gradually becomes smaller;

[0105] 3) The black circle completely disappears, and at this time the gas inside the microcavity has completely dissolved.

[0106] Further, in Step 5, the dissolution rate of the gas in the liquid medium is calculated, specifically as follows:

[0107] 1) According to the state equation of ideal gas: where n is the number of moles of the gas (unit: mol), P is the pressure of the gas (unit: Pa), V is the volume of the gas (unit: m 3 ), R is the molar gas constant, R = 8.314 J·mol -1 ·K -1 , and T is the thermodynamic temperature (unit: K). The dissolution rate of the gas in the liquid medium under constant temperature and pressure is where V 腔 is the internal volume of a single microcavity; P and T are the measured values, P is provided by the pressure gauge 41, and T is provided by the temperature sensor 43; t is the time for the gas to dissolve inside a single microcavity, that is, the time taken for the entire process from the appearance of the bubble to the complete disappearance of the bubble.

[0108] 2) Select at least 5 microcavities at different positions in the recorded image, calculate the dissolution rate of the gas inside a single microcavity, and take the average value as the measured value of the dissolution rate of the gas in the liquid. The standard deviation of multiple measurements is used as the error value.

[0109] Furthermore, the test substrate 7 is provided with uniformly arranged microcavities for chemical reactions. Each microcavity opens only on one side facing the planar light source assembly 1 on the test substrate 7, and this opening serves as the reaction chamber for the internal gas and the test liquid. Each uniformly arranged microcavity does not penetrate inside the test substrate 7; the amount of internal gas in a single microcavity can be measured.

[0110] Furthermore, the shape of the microcavity includes square or circular. The characteristic dimension at the opening should be such that when a specific liquid enters the microcavity, it is not significantly disturbed at the edge of the opening; the depth h of the microcavity opening is less than or equal to the shortest side length or diameter at the microcavity opening for the current specific liquid; the spacing L between microcavities is not less than the shortest side length or diameter at the microcavity opening for the current specific liquid.

[0111] It should be emphasized that the above specific embodiments are merely explanations of the present invention and are not limitations thereof. Those skilled in the art can make modifications to the above embodiments without creative contributions according to needs after reading this specification, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. An in-situ visualization rapid measurement method for measuring the gas dissolution rate, which is based on an in-situ observation device for measuring the dissolution rate of trace gases in a liquid medium. The device includes an observation system (8) arranged at the upper part, a test substrate (7) arranged in the middle, and a planar light source assembly (1) arranged at the lower part; the planar light source assembly (1) provides a visual background illumination condition for the test substrate (7); the observation system (8) is used to record and save the measurement process in real time, and adjust the focal length and magnification to make the image clearly visible; the test substrate (7) is made into a transparent test substrate, and the optical photo detection method is used as the test method; the test substrate (7) is provided with uniformly arranged microcavities for gas dissolution reaction, and the size of the microcavities is between 1 μm and 10 mm, which serves as the reaction chamber for testing the gas dissolution rate; each microcavity only opens on one side facing the planar light source assembly (1) on the test substrate (7), and each uniformly arranged microcavity does not penetrate inside the test substrate (7); the internal gas volume of a single microcavity can be measured; A highly transparent heat-resistant glass main body box (6) that surrounds the test substrate (7) is also provided outside the test substrate (7). The test substrate (7) is horizontally mounted on the internal liquid box (62) of the highly transparent heat-resistant glass main body box (6). The highly transparent heat-resistant glass main body box (6) provides an external carrier for enclosing, pressurizing, temperature controlling, and liquid containing for the measurement process; on the external sealed box (61) of the highly transparent heat-resistant glass main body box (6), a liquid injection assembly (2), a gas pressure and temperature monitoring assembly (4), and a gas injection assembly (5) are also provided; temperature heating assemblies (3) are also respectively provided on the inner box body of the highly transparent heat-resistant glass main body box (6) and on the liquid injection assembly (2); the liquid injection assembly (2) provides liquid injection for the measurement process of the test substrate (7) and submerges the test substrate (7); the temperature heating assembly (3) provides a stable and reliable ambient temperature for measuring the dissolution rate at different temperatures; the gas pressure and temperature monitoring assembly (4) monitors the changes in gas pressure and temperature during the measurement process and feeds back to the temperature heating assembly (3) and the gas injection assembly (5) at any time; the gas injection assembly (5) provides test gas for the measurement process and controls the reaction pressure; It is characterized in that: This method includes the following steps: Step 1: Place the test substrate (7) into the box body and firmly fix it horizontally using the sample clamp (63); Step 2: Turn on the planar light source assembly (1) and adjust the light intensity, and adjust the CCD camera (81) to focus on the microcavities of the test substrate (7); Step 3: Evacuate the inside of the highly transparent heat-resistant glass main body box (6), then inject the test gas into the highly transparent heat-resistant glass main body box (6) through the gas injection assembly (5), and use the gas pressure and temperature monitoring assembly (4) to monitor the internal gas pressure of the box body and adjust the gas pressure and temperature through the gas injection assembly (5) and the temperature heating assembly (3); Step 4: Inject the test liquid into the internal liquid box (62) through the liquid injection assembly (2) until the microcavities at the bottom of the test substrate (7) are quickly submerged, and at this time, bubbles are generated inside the microcavities; Step Five: Use a CCD camera (81) and a data acquisition and recording system (82) to observe and record in real time the generation, dissolution, and disappearance process of bubbles inside the microcavity of the test substrate (7), record the time and images of the entire process, and calculate the dissolution rate of the gas in the liquid medium; Step Six: After the test, first use the air vent valve (54) to balance the internal and external air pressures, use a syringe (22) to pump out the liquid from the box body, open the external sealed box (61) to take out the test substrate (7), wash it for recycling, and clean the inside of the high-transparency heat-resistant glass main box (6) for the next use.

2. The in-situ visualization rapid measurement method for measuring the gas dissolution rate according to claim 1, characterized in that: The step of placing the test substrate (7) into the box body in Step One is specifically as follows: After the test substrate (7) is installed, the microcavity sample surface remains in a horizontal state, which is convenient for ensuring that when the test liquid is injected into the internal liquid box (62) through the liquid injection assembly (2) in Step Four and the liquid level approaches the microcavity at the bottom of the test substrate (7), the microcavity array for testing can be covered by the liquid medium as much as possible at the same time.

3. The in-situ visualization rapid measurement method for measuring the gas dissolution rate according to claim 1, wherein: The step of injecting the test gas into the high-transparency heat-resistant glass main box (6) through the gas injection assembly (5) in Step Three is specifically as follows: The pressure valve (53) of the gas injection assembly (5) is opened when ventilating the external sealed box (61) and the internal liquid box (62) of the high-transparency heat-resistant glass main box (6), and is closed before injecting liquid into the internal liquid box (62); the air vent valve (54) of the gas injection assembly (5) has two functions: evacuating and adjusting the air pressure; it is connected to a vacuum pump when evacuating, discharges gas when adjusting the air pressure, and is closed at other times.

4. The in-situ visualization rapid measurement method for measuring the gas dissolution rate according to claim 1, characterized in that: The step of injecting the test liquid into the internal liquid box (62) through the liquid injection assembly (2) in Step Four until the microcavity at the bottom of the test substrate (7) is quickly submerged, and at this time, bubbles are generated inside the microcavity; The specific process is as follows: 1) Before the test, place the test liquid in a vacuum drying oven in advance for degassing operation, and pump the bottom liquid into a syringe (22) for standby before liquid injection; 2) When injecting liquid, turn on the CCD camera (81) and the data acquisition and recording system (82) before bubbles are generated on the test substrate (7) to record the complete process from bubble generation to disappearance; 3) When the liquid level approaches the microcavity at the bottom of the test substrate (7), accelerate the liquid injection to make the liquid level rise rapidly to ensure that the microcavity array for testing can be covered by the liquid medium as much as possible at the same time; 4) The liquid injection assembly (2) injects the test liquid into the internal liquid box (62) until the microcavity at the bottom of the test substrate (7) is quickly submerged, and at this time, bubbles are generated inside the microcavity; 5) Stop injecting liquid when the liquid is higher than the bottom of the internal and external box air pressure balance through hole (64).

5. The in-situ visualization rapid measurement method for measuring the gas dissolution rate according to claim 4, wherein: The test liquid is required to be able to transmit light and be free of impurities, and the light transmittance of the test liquid, the light transmittance of the external sealed box (61) and the internal liquid box (62), and the light transmittance of the test substrate (7) match, and the light transmittance is above 90%.

6. The in-situ visualization rapid measurement method for measuring the gas dissolution rate according to claim 1, wherein: The step of observing and recording in real time the generation, dissolution, and disappearance process of bubbles inside the microcavity of the test substrate (7) in Step Five, and the disappearance process is the entire process from the appearance of bubbles to the complete disappearance of bubbles, Specifically as follows: 1) In the initial state, the black edge circle of the microcavity is the boundary of the bubble; 2) As the gas dissolves, this black circle gradually becomes smaller; 3) This black circle completely disappears, at which time the gas inside the microcavity has completely dissolved.

7. The in-situ visualization rapid measurement method for measuring the gas dissolution rate according to claim 1, characterized in that: The calculation of the dissolution rate of the gas in the liquid medium in step five is specifically as follows: 1) According to the state equation of ideal gas: where n is the number of moles of the gas, in mol, P is the pressure of the gas, in Pa, V is the volume of the gas, in m 3 , R is the molar gas constant, R = 8.314 J·mol -1 ·K -1 , T is the thermodynamic temperature, in K; the dissolution rate of the gas in the liquid medium under constant temperature and pressure is where V 腔 is the internal volume of a single microcavity; P and T are measured values, P is provided by the pressure gauge (41), and T is provided by the temperature sensor (43); t is the gas dissolution time inside a single microcavity, that is, the time taken for the entire process from the appearance of the bubble to the complete disappearance of the bubble; 2) Select at least 5 microcavities at different positions in the recorded image, calculate the dissolution rate of the gas inside a single microcavity and then take the average as the measured value of the gas dissolution rate in the liquid, and take the standard deviation of multiple measurements as the error value.

8. An in-situ visualization rapid measurement method for measuring the gas dissolution rate according to claim 1, characterized in that: The shape of the microcavity includes square or circular, and the characteristic dimension at its opening should ensure that there is no obvious disturbance at the opening edge when the test liquid enters the microcavity; the opening depth h of the microcavity is less than or equal to the side length or diameter of the opening of the microcavity; the distance L between microcavities is not less than the side length or diameter of the opening of the microcavity.

Images