A microfluidic chip and a method for regulating the formation and movement processes of monodisperse nitrogen microbubbles by an ionic liquid

Abstract

The present invention provides a microfluidic chip and a method for regulating the formation and movement process of monodisperse nitrogen microbubbles by an ionic liquid, which relates to the technical field of microbubble preparation and microfluidic characteristics analysis, and is used to solve the technical problem that it is difficult to controllably prepare monodisperse nitrogen microbubbles with stable flow on a microscale in a gas-ionic liquid system. The microfluidic chip includes a base platform, on which an injection tube and a collection tube are provided. The outlet of the injection tube is a conical tip, and the conical tip is horizontally inserted into the collection tube. The injection tube and the collection tube are connected by a connecting tube, and the connecting tube is sleeved on the injection tube and the collection tube, and the inner diameter of the connecting tube is larger than the outer diameters of the injection tube and the collection tube. The formation and movement process of nitrogen microbubbles in the microfluidic chip are regulated by changing the type of ionic liquid and the flow rate of the ionic liquid. The microfluidic chip has stable physical and chemical properties, is simple to prepare, and has a low cost. The generated microbubbles have uniform sizes, controllable generation frequencies, and stable flow.

Description

Technical Field

[0001] The present invention relates to the technical field of microbubble preparation and microfluidic property analysis, and in particular to a microfluidic chip and a method for regulating the formation and movement process of monodisperse nitrogen microbubbles by ionic liquids. Background Art

[0002] Ionic liquids are a class of salts with low melting points and are liquid at temperatures below 373.15 K. Compared with conventional organic solvents and electrolyte solutions, ionic liquids have many advantages, such as low vapor pressure, low melting point, and good solubility in a variety of inorganic and organic substances at room temperature. Therefore, ionic liquids have good application prospects as reactants or separation media. Currently, more and more researchers are applying ionic liquids to gas-liquid separation and reaction processes. Combining with the recent trend of miniaturization of chemical processes, the flow and dispersion kinetics of gas-ionic liquid systems at the microscale become increasingly important to improve the efficiency and safety of chemical processes / reactions.

[0003] The key to gas-liquid processes at the microscale is flow pattern control and bubble transport. Microscale bubbles have a large specific surface area, a small transport distance, and a high surface energy, and are the main body of basic research on microscale mass transfer and chemical reaction processes. Ideal microbubbles have the characteristics of high monodispersity, controllable generation frequency, and stable flow. Currently, ultrasonic or mechanical stirring methods are mostly used to generate microbubbles. Although these methods have the advantages of simplicity, convenience, and low cost in generating microbubbles, the generated microbubbles have uneven sizes, difficult-to-control generation frequencies, and unstable bubble velocities, which are not conducive to the study of the flow and dispersion kinetics of gas-ionic liquid systems at the microscale. Summary of the Invention

[0004] Aiming at the technical problem that it is difficult to controllably prepare monodisperse nitrogen microbubbles with stable flow in the existing gas-ionic liquid system at the microscale, the present invention proposes a microfluidic chip and a method for regulating the formation and movement process of monodisperse nitrogen microbubbles by ionic liquids. The nitrogen microbubbles in the prepared microfluidic chip have the characteristics of uniform size, controllable generation frequency, and stable flow. Moreover, this method is efficient, simple, and has good repeatability. At the same time, it also helps to further explore the flow and dispersion kinetics of gas-ionic liquid systems at the microscale and has reference significance for the intensification of microchemical reaction processes.

[0005] In order to achieve the above object, the technical solution of the present invention is realized as follows:

[0006] A microfluidic chip includes a base platform, on which an injection tube and a collection tube are provided. The outlet of the injection tube is a conical tip, which is horizontally inserted into the collection tube. The injection tube and the collection tube are connected by a connecting tube. The connecting tube is sleeved on the injection tube and the collection tube. The inner diameter of the connecting tube is larger than the outer diameters of the injection tube and the collection tube. The space between the connecting tube and the collection tube is filled with a sealing glue layer for sealing. An annular liquid inlet communicating with the collection tube is formed between the connecting tube and the injection tube.

[0007] The inlet of the injection tube is a circular glass tube with an inner diameter of 0.7 - 1.7 mm and an outer diameter of 1.0 - 2.3 mm.

[0008] The collection tube is a circular glass tube with an inner diameter of 0.7 - 1.7 mm and an outer diameter of 1.0 - 2.3 mm.

[0009] Preferably, the inlet of the injection tube is a circular glass tube with an inner diameter of 0.7 mm and an outer diameter of 1.0 mm.

[0010] The connecting tube is a circular glass tube with an inner diameter of 1.2 - 2.5 mm and an outer diameter of 1.6 - 3.5 mm. The connecting tube can be sleeved on the injection tube and the collection tube, and a certain gap is reserved to form an annular liquid inlet.

[0011] The outlet aperture of the injection tube ranges from 10 - 150 μm. The front end of the circular glass tube is drawn into a cone by a microelectrode puller to form a conical tip with a conical hole structure, and conical holes with controllable sizes can be prepared according to different experimental requirements.

[0012] The length of the conical tip inserted into the collection tube is 0.8 - 1.2 mm. The conical tip should avoid being inserted too deeply to cause the injection tube and the collection tube to abut. It should be ensured that the liquid-phase fluid entering from the annular liquid inlet can smoothly enter the collection tube.

[0013] The base platform is a transparent alumina ceramic sheet, a silicate glass sheet or a quartz glass sheet. The base platform can also be other inorganic non-metallic materials with good light transmittance and chemical corrosion resistance.

[0014] A method for regulating the formation and movement process of monodisperse nitrogen microbubbles by ionic liquid. The liquid phase and the gas phase are respectively injected into the microfluidic chip to study the formation and movement process of microbubbles. The specific steps are as follows: Connect the inlet of the injection tube to a gas syringe through a conduit, and introduce gas into the injection tube; A joint is provided at the annular liquid inlet, and the joint is connected to a liquid syringe through a conduit, and introduce liquid into the connecting tube. The gas phase and the liquid phase contact at the outlet of the injection tube, and microbubbles are formed in the collection tube; Collect the two-phase flow images in the collection tube through the optical microscope of a high-speed camera, and study the formation and movement process of microbubbles according to the obtained images.

[0015] The gas phase is nitrogen and the liquid phase is an ionic liquid.

[0016] The liquid phase is one of ionic liquids 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim][BF4]), 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]), and 1-hexyl-3-methylimidazolium tetrafluoroborate ([Hmim][BF4]).

[0017] The flow rate of the gas phase introduced into the syringe tube is 100 - 400 μL / min, and the flow rate of the liquid phase introduced into the connecting tube is 600 - 1300 μL / min.

[0018] The size of the formed microbubbles is 200 - 500 μm, the generation frequency is 20 - 250 Hz, and the movement speed is 0.03 - 0.1 m / s. The relative standard deviations of the microbubble size, generation frequency, and movement speed are all less than 3%.

[0019] The microfluidic chip of the present invention can be used in fields such as the preparation of microbubbles, droplets, solid particles, and gas absorption.

[0020] Advantages of the present invention:

[0021] (1) The microfluidic chip of the present invention has stable physical and chemical properties, good heat resistance, and good transparency.

[0022] (2) By controlling the flow rate of the ionic liquid under a constant gas phase flow rate, the present invention can regulate the size, generation frequency, and movement speed of nitrogen microbubbles, and further achieve the purpose of regulating the formation and movement process of monodisperse nitrogen microbubbles.

[0023] (3) Using different types of ionic liquids as the liquid phase, under a constant gas phase flow rate and liquid phase flow rate, the present invention can regulate the size, generation frequency, and movement speed of nitrogen microbubbles, and further achieve the purpose of regulating the formation and movement process of monodisperse nitrogen microbubbles.

[0024] (4) The microbubbles prepared by the present invention have the advantages of uniform size, controllable frequency, and stable flow, and are good microbubble generators. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0026] Figure 1Schematic diagram of the microfluidic chip structure; in the figure: 1, conduit; 2, conical joint; 3, injection tube; 4, connecting tube; 5, collection tube; 6, base.

[0027] Figure 2 Microscopic photographs in different ionic liquids in the microfluidic chip, Q G = 100 μL·min -1 , Q L = 600 μL·min -1 ; in the figure (i) [Hmim][BF4], (ii) [Bmim][BF4], (iii) [Emim][BF4]. Specific implementation manners

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0029] The experimental methods used in the following embodiments are all conventional methods unless otherwise specified. The materials, reagents, methods and instruments used, unless otherwise specified, are all conventional materials, reagents, methods and instruments in the art, and those skilled in the art can obtain them through commercial channels.

[0030] Example 1

[0031] A microfluidic chip, as Figure 1 shown, includes a base 6. An injection tube 3 and a collection tube 5 are provided on the base 6, and the injection tube 3 and the collection tube 5 are bonded to the base 6. The outlet of the injection tube 3 is a conical tip, and the conical tip is horizontally inserted into the collection tube 5. An annular space is formed between the injection tube 3 and the collection tube 5. The injection tube 3 and the collection tube 5 are connected by a connecting tube 4. The connecting tube 4 is sleeved on the injection tube 3 and the collection tube 5. The inner diameter of the connecting tube 4 is larger than the outer diameters of the injection tube 3 and the collection tube 5. The connection between the connecting tube 4 and the collection tube 5 is filled with a sealant layer for sealing. An annular liquid inlet communicating with the collection tube 5 is formed between the connecting tube 4 and the injection tube 3. The outlet of the collection tube 5 communicates with the atmosphere.

[0032] Example 2

[0033] A microfluidic chip, as Figure 1As shown in the figure, the inlet of the injection tube 3 is a circular glass tube with an inner diameter of 0.7 - 1.7 mm and an outer diameter of 1.0 - 2.3 mm, and the dimensional error is less than 0.01 mm. The collection tube 5 is a circular glass tube with an inner diameter of 0.7 - 1.7 mm and an outer diameter of 1.0 - 2.3 mm, and the dimensional error is less than 0.01 mm. The inner and outer diameters of the inlet of the collection tube 5 and the injection tube 3 are equal, and the two are located on the same axis, enabling the conical tip to be located on the axis of the collection tube 5, ensuring the uniformity of the formation of microbubbles.

[0034] The connecting tube 4 is a circular glass tube with an inner diameter of 1.2 - 2.5 mm and an outer diameter of 1.6 - 3.5 mm. The connecting tube 4 can be sleeved on the injection tube 3 and the collection tube 5, and a certain gap is reserved to form an annular liquid inlet. The front end of the circular glass tube is drawn into a cone by a microelectrode puller to form a conical tip with a conical hole structure. The outlet aperture range of the injection tube 3 is 10 - 150 μm, and conical holes with controllable sizes can be prepared according to different experimental requirements. The length of the conical tip inserted into the collection tube 5 is 0.8 - 1.2 mm. The conical tip should be prevented from being inserted too deeply to cause the injection tube 3 and the collection tube 5 to abut, and it should be ensured that the liquid phase fluid entering from the annular liquid inlet can smoothly enter the collection tube 5.

[0035] Other structures are the same as those in Embodiment 1.

[0036] Embodiment 3

[0037] A microfluidic chip, as Figure 1 shown, the base 6 is a transparent alumina ceramic sheet, a silicate glass sheet or a quartz glass sheet. The base 6 can also be other inorganic non-metallic materials with good light transmittance and chemical corrosion resistance. The base 6, the injection tube 3, the collection tube 5 and the connecting tube 4 are all made of transparent materials. During the process of preparing bubbles, a high-speed camera and a microscope are used in combination to record the formation and movement process of microbubbles.

[0038] The inlet of the injection tube 3 and the annular liquid inlet are respectively connected to two syringes through the conduit 1. Among them, the inlet of the injection tube 3 is connected to the gas-phase syringe, and the annular liquid inlet is connected to the liquid-phase syringe. During the process of preparing bubbles, the gas-phase flow rate is 100 - 400 μL / min, and the liquid-phase flow rate is 600 - 1300 μL / min. The gas phase is nitrogen, and the liquid phase is an ionic liquid. A conical joint 2 is provided at the annular liquid inlet. The conduit 1 is connected to the conical joint 2. The conical joint 2 covers the annular liquid inlet and is bonded with sealant to form a closed channel between the conical joint 2 and the annular liquid inlet. By feeding the gas-liquid two-phase into the microchip, the gas phase meets the liquid phase at the outlet of the conical tip. The gas phase is sheared by the liquid phase to form bubbles with different shapes and flows in the collection tube 5 towards the outlet direction together with the liquid phase.

[0039] The other structures are the same as those in Embodiment 2.

[0040] Embodiment 4

[0041] A microfluidic chip, as Figure 1 shown, is different from Embodiment 3 in that two circular glass tubes with an inner diameter of 0.7 mm and an outer diameter of 1.0 mm are used as the inlets of the injection tube 3 and the collection tube 5, and the connecting tube 4 is a circular glass tube with an inner diameter of 1.2 mm and an outer diameter of 1.6 mm. The inner diameter of the conical tip in the injection tube 3 of the microfluidic chip is 10 μm, the base 6 is a quartz glass sheet, and the conduit 1 is a plastic conduit.

[0042] Embodiment 5

[0043] A microfluidic chip, as Figure 1 shown, is different from Embodiment 3 in that the collection tube 5 is a circular glass tube with an inner diameter of 1.2 mm and an outer diameter of 1.6 mm, the connecting tube 4 is a circular glass tube with an inner diameter of 1.7 mm and an outer diameter of 2.3 mm, and the inner diameter of the conical tip in the injection tube 3 of the microfluidic chip is 40 μm.

[0044] Embodiment 6

[0045] A microfluidic chip, as Figure 1 shown, is different from Embodiment 3 in that the collection tube is a circular glass tube with an inner diameter of 1.7 mm and an outer diameter of 2.3 mm, the connecting tube 4 is a circular glass tube with an inner diameter of 2.5 mm and an outer diameter of 3.5 mm, and the inner diameter of the conical tip in the injection tube 3 of the microfluidic chip is 100 μm.

[0046] Embodiment 7

[0047] A microfluidic chip, as Figure 1 shown, is different from Embodiment 3 in that two circular glass tubes with an inner diameter of 0.7 mm and an outer diameter of 1.0 mm are used as the inlets of the injection tube 3 and the collection tube 5, and the connecting tube 4 is a circular glass tube with an inner diameter of 1.2 mm and an outer diameter of 1.6 mm. The inner diameter of the conical tip in the injection tube 3 of the microfluidic chip is 150 μm.

[0048] Embodiment 8

[0049] A method for regulating the formation and movement process of monodisperse nitrogen microbubbles by an ionic liquid, as Figure 1As shown in the figure, the chip includes a base 6, on which an injection tube 3 and a collection tube 5 are provided. The injection tube 3 and the collection tube 5 are bonded to the base 6. The outlet of the injection tube 3 is a conical tip, which is horizontally inserted into the collection tube 5, and an annular space is formed between the injection tube 3 and the collection tube 5. The injection tube 3 and the collection tube 5 are connected by a connecting tube 4. The connecting tube 4 is sleeved on the injection tube 3 and the collection tube 5. The inner diameter of the connecting tube 4 is larger than the outer diameters of the injection tube 3 and the collection tube 5. The space between the connecting tube 4 and the collection tube 5 is filled with a sealant layer for sealing. An annular liquid inlet communicating with the collection tube 5 is formed between the connecting tube 4 and the injection tube 3. The outlet of the collection tube 5 communicates with the atmosphere. The inlet of the injection tube 3 and the annular liquid inlet are respectively connected to two syringes through a conduit 1. Among them, the inlet of the injection tube 3 is connected to a gas-phase syringe, and the annular liquid inlet is connected to a liquid-phase syringe. During the process of preparing bubbles, the flow rate of the gas phase is 100 - 400 μL / min, and the flow rate of the liquid phase is 600 - 1300 μL / min. The gas phase is nitrogen, and the liquid phase is an ionic liquid. A conical joint 2 is provided at the annular liquid inlet. The conduit 1 is connected to the conical joint 2. The conical joint 2 covers the annular liquid inlet and is bonded with a sealant, so that a closed channel is formed between the conical joint 2 and the annular liquid inlet. By feeding the gas-liquid two-phase into the microchip, the gas phase meets the liquid phase at the outlet of the conical tip, and the gas phase is sheared by the liquid phase to form bubbles with different shapes, and flows in the collection tube 5 towards the outlet direction together with the liquid phase.

[0050] Example 9

[0051] A method for regulating the formation and movement process of monodisperse nitrogen microbubbles by an ionic liquid, using the device described in Example 4, includes the following steps: The injection pump drives the syringe to feed nitrogen and ionic liquid [Hmim][BF4] into the microfluidic chip at a constant flow rate through a plastic conduit 1. Nitrogen enters from the injection tube, and [Hmim][BF4] enters from the external connecting tube. The gas-liquid two-phase contacts at the tip of the injection tube, and the gas phase is sheared by the liquid phase to form bubbles with different shapes, and flows towards the outlet direction together with the liquid phase. During the experiment, an optical microscope equipped with a high-speed camera is used to collect the two-phase flow images in the collection tube, and the changes in the size, generation frequency, and movement speed of the microbubbles are analyzed by collecting the images in the collection tube through the high-speed camera. The experimental parameters are set as the liquid-phase flow rate of 1300 μL / min, the gas-phase flow rate of 100 μL / min, and the experimental temperature of 20 °C. Finally, the obtained bubble diameter is about 213 μm, the generation frequency is about 100 Hz, the movement speed is about 0.076 m / s, and the relative standard deviations of the microbubble size, generation frequency, and movement speed are all less than 3%.

[0052] Example 10

[0053] A method for regulating the formation and movement process of monodisperse nitrogen microbubbles by using an ionic liquid. Replace the liquid phase with the ionic liquid [Bmim][BF4], and the other steps are the same as in Example 8. The finally obtained bubble diameter is about 248 μm, the generation frequency is about 134 Hz, and the movement speed is about 0.077 m / s. The relative standard deviations of the microbubble size, generation frequency, and movement speed are all less than 3%.

[0054] Example 11

[0055] A method for regulating the formation and movement process of monodisperse nitrogen microbubbles by using an ionic liquid. Replace the liquid phase with the ionic liquid [Emim][BF4], and the other steps are the same as in Example 8. The finally obtained bubble diameter is about 364 μm, the generation frequency is about 87 Hz, and the movement speed is about 0.081 m / s. The relative standard deviations of the microbubble size, generation frequency, and movement speed are all less than 3%.

[0056] Example 12

[0057] A method for regulating the formation and movement process of monodisperse nitrogen microbubbles by using an ionic liquid. Replace the experimental parameter settings with a liquid phase flow rate of 600 μL / min and a gas phase flow rate of 100 μL / min. The other steps are the same as in Example 8. The morphology of the bubbles is as shown in Figure 2 (i). The finally obtained bubble diameter is about 331 μm, the generation frequency is about 28 Hz, and the movement speed is about 0.035 m / s. The relative standard deviations of the microbubble size, generation frequency, and movement speed are all less than 3%.

[0058] Example 13

[0059] A method for regulating the formation and movement process of monodisperse nitrogen microbubbles by using an ionic liquid. Replace the experimental parameter settings with a liquid phase flow rate of 600 μL / min and a gas phase flow rate of 100 μL / min. Replace the liquid phase with the ionic liquid [Bmim][BF4]. The other steps are the same as in Example 1. The morphology of the bubbles is as shown in Figure 2 (ii). The finally obtained bubble diameter is about 354 μm, the generation frequency is about 58 Hz, and the movement speed is about 0.037 m / s. The relative standard deviations of the microbubble size, generation frequency, and movement speed are all less than 3%.

[0060] Example 14

[0061] A method for regulating the formation and movement process of monodisperse nitrogen microbubbles by using an ionic liquid. Replace the experimental parameter settings with a liquid phase flow rate of 600 μL / min and a gas phase flow rate of 100 μL / min. Replace the liquid phase with the ionic liquid [Emim][BF4]. The other steps are the same as in Example 1. The morphology of the bubbles is as shown in Figure 2(iii), the finally obtained bubble diameter is about 442 μm, the generation frequency is about 41 Hz, and the movement speed is about 0.036 m / s. The relative standard deviations of the microbubble size, generation frequency, and movement speed are all less than 3%.

[0062] Example 15

[0063] A method for regulating the formation and movement process of monodisperse nitrogen microbubbles by an ionic liquid. The experimental parameter settings are changed to a liquid phase flow rate of 1300 μL / min and a gas phase flow rate of 300 μL / min. The liquid phase is replaced with the ionic liquid [Bmim][BF4], and other steps are the same as in Example 1. The finally obtained bubble diameter is about 281 μm, the generation frequency is about 242 Hz, and the movement speed is about 0.080 m / s. The relative standard deviations of the microbubble size, generation frequency, and movement speed are all less than 3%.

[0064] Example 16

[0065] A method for regulating the formation and movement process of monodisperse nitrogen microbubbles by an ionic liquid. The experimental parameter settings are changed to a liquid phase flow rate of 1300 μL / min and a gas phase flow rate of 400 μL / min. The liquid phase is replaced with the ionic liquid [Emim][BF4], and other steps are the same as in Example 1. The finally obtained bubble diameter is about 376 μm, the generation frequency is about 238 Hz, and the movement speed is about 0.097 m / s. The relative standard deviations of the microbubble size, generation frequency, and movement speed are all less than 3%.

[0066] In the above experiments, each group of experiments was repeated 3 times. The relative standard deviations of the microbubble size, generation frequency, and movement speed obtained by data processing are all less than 3%, which proves that the method for regulating the formation and movement process of monodisperse nitrogen microbubbles by an ionic liquid in a microfluidic chip provided by the present invention enables the microbubbles generated in the microfluidic chip to have the advantages of uniform size, controllable frequency, and stable flow.

[0067] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for regulating the formation and movement processes of monodisperse nitrogen microbubbles by an ionic liquid, characterized in that A microfluidic chip is adopted to inject the liquid phase and the gas phase into the microfluidic chip respectively for the study of the formation and movement process of microbubbles; The microfluidic chip includes a base (6). An injection tube (3) and a collection tube (5) are arranged on the base (6). The outlet of the injection tube (3) is a conical tip, and the conical tip is horizontally inserted into the collection tube (5). The injection tube (3) and the collection tube (5) are connected by a connecting tube (4). The connecting tube (4) is sleeved on the injection tube (3) and the collection tube (5). The inner diameter of the connecting tube (4) is larger than the outer diameters of the injection tube (3) and the collection tube (5). A sealing glue layer is filled between the connecting tube (4) and the collection tube (5) for sealing. An annular liquid inlet communicating with the collection tube (5) is formed between the connecting tube (4) and the injection tube (3); The inlet of the injection tube (3) is a circular glass tube with an inner diameter of 0.7 - 1.7 mm and an outer diameter of 1.0 - 2.3 mm; the outlet aperture range of the injection tube (3) is 10 - 150 µm; the length of the conical tip inserted into the collection tube (5) is 0.8 - 1.2 mm; the collection tube (5) is a circular glass tube with an inner diameter of 0.7 - 1.7 mm and an outer diameter of 1.0 - 2.3 mm; The connecting tube (4) is a circular glass tube with an inner diameter of 1.2 - 2.5 mm and an outer diameter of 1.6 - 3.5 mm; It includes the following steps: Connect the inlet of the injection tube (3) to a gas syringe through a conduit (1), and introduce gas into the injection tube (3); A joint (2) is arranged at the annular liquid inlet. The joint (2) is connected to a liquid syringe through a conduit (1), and introduce liquid into the connecting tube (4). The gas phase and the liquid phase contact at the outlet of the injection tube (3) to form microbubbles in the collection tube (5); Collect the two-phase flow image in the collection tube through the optical microscope of a high-speed camera, and study the formation and movement process of microbubbles according to the obtained image; The gas phase is nitrogen; the liquid phase is one of ionic liquids 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate or 1-hexyl-3-methylimidazolium tetrafluoroborate.

2. The method for regulating the formation and movement process of monodisperse nitrogen microbubbles by an ionic liquid according to claim 1, wherein The inlet of the injection tube (3) is a circular glass tube with an inner diameter of 0.7 mm and an outer diameter of 1.0 mm.

3. The method for regulating the formation and movement process of monodisperse nitrogen microbubbles by an ionic liquid according to claim 2, wherein, The base (6) is a transparent alumina ceramic sheet, a silicate glass sheet or a quartz glass sheet.

4. The method for regulating the formation and movement process of monodisperse nitrogen microbubbles by an ionic liquid according to claim 1, characterized in that The flow rate of the gas introduced into the injection tube (3) is 100 - 400 µL / min, and the flow rate of the liquid introduced into the connecting tube (4) is 600 - 1300 µL / min.

5. The method for regulating the formation and movement process of monodisperse nitrogen microbubbles by an ionic liquid according to claim 1, wherein The size of the formed microbubbles is 200 - 500 µm, the generation frequency is 20 - 250 Hz, and the movement speed is 0.03 - 0.1 m / s.

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