Microfluid in-situ pH measurement system and measurement method

Abstract

The invention discloses a microfluid in-situ pH measurement system and a measurement method, and relates to the technical field of solution detection. A micro-fluidic chip is arranged in an accommodating space of a reaction kettle body; the confining pressure pump is connected with the confining pressure fluid container and the accommodating space; the injection pump is connected with the first container and the second container, and the first container and the second container are connected with the micro-fluidic chip; the camera device, the objective lens of the microscope, the semi-transparent and semi-reflecting mirror and the mobile platform are correspondingly arranged, and the microscope light source is arranged on the mobile platform; the laser light source can emit laser towards the semi-transparent and semi-reflective mirror, and the semi-transparent and semi-reflective mirror can reflect the laser so that the laser can be received by the laser spectrometer after passing through the micro-fluidic chip. Therefore, the spectrum pH measurement module is coupled in the microfluid control system, the in-situ pH of the microfluid to be measured can be reliably and accurately measured, the time and space distribution of the in-situ pH of the microfluid to be measured can be obtained, and the problem that no device capable of measuring the in-situ pH of the microfluid to be measured exists at present is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of solution detection, and in particular to a microfluid in-situ pH measurement system and a measurement method of the microfluid in-situ pH measurement system. Background Art

[0002] Microfluidic technology is widely used in biology, chemistry, materials and other fields. In recent years, it has also gradually attracted attention in the fields of geological energy and carbon sequestration. As an important physical and chemical parameter of fluids, the accurate measurement of hydrogen ion concentration index (pH) is of great significance. However, in the related technology, there is no device that can reliably and accurately measure the in-situ pH of the microfluid to be tested. Therefore, there is an urgent need for a device that can reliably and accurately measure the in-situ pH of the microfluid to be tested. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a microfluid in-situ pH measurement system, which can reliably and accurately measure the in-situ pH of a microfluid to be measured.

[0004] The present invention further proposes a measurement method for a microfluid in-situ pH measurement system.

[0005] The microfluidic in-situ pH measurement system according to the present invention comprises: a reactor cover, a reactor body, and a microfluidic chip, wherein the microfluidic chip is arranged in the accommodation space of the reactor body; a confining pressure pump and a confining pressure fluid container, wherein the confining pressure pump is connected to the confining pressure fluid container and the accommodation space; a first container, a second container, and an injection pump, wherein the injection pump is connected to the first container and the second container, and the first container and the second container are connected to the microfluidic chip; a microscope, a camera device, a microscope light source, a mobile platform, and a semi-transparent and semi-reflective mirror, wherein the camera device, the objective lens of the microscope, the semi-transparent and semi-reflective mirror, and the mobile platform are arranged in sequence along a first direction and are correspondingly arranged, and the microscope light source is arranged on the mobile platform; a laser light source and a laser spectrometer, wherein the laser light source can emit laser light toward the semi-transparent and semi-reflective mirror, and the semi-transparent and semi-reflective mirror can reflect the laser light so that the laser light passes through the microfluidic chip and is received by the laser spectrometer.

[0006] According to the microfluidic in-situ pH measurement system of the present invention, by coupling a spectroscopic pH measurement module in a microfluidic control system, the in-situ pH of the microfluid to be measured can be reliably and accurately measured, and the time and spatial distribution of the in-situ pH of the microfluid to be measured can be obtained, thereby solving the problem that there is currently no device capable of measuring the in-situ pH of the microfluid to be measured.

[0007] In some examples of the present invention, the microfluidic in-situ pH measurement system also includes: a first collimator and a second collimator, along the second direction, the first collimator is arranged on one side of the semi-transparent and semi-reflective mirror, the second collimator is arranged on the movable platform, the laser light source is connected to the first collimator, the laser spectrometer is connected to the second collimator, the laser emitted by the laser light source passes through the first collimator to the semi-transparent and semi-reflective mirror, and the laser passes through the microfluidic chip to the second collimator, wherein the second direction is perpendicular to the first direction.

[0008] In some examples of the present invention, the microfluidic in-situ pH measurement system further includes: a first optical fiber and a second optical fiber, the laser light source is connected to the first collimator through the first optical fiber, and the laser spectrometer is connected to the second collimator through the second optical fiber.

[0009] In some examples of the present invention, the reactor cover has a first window, the reactor body has a second window, the first window is located between the microfluidic chip and the semi-transparent and semi-reflective mirror, and the second window is located between the microfluidic chip and the second collimator.

[0010] In some examples of the present invention, the microfluidic in-situ pH measurement system further includes: a temperature control device, and the reactor body is disposed in the temperature control device.

[0011] In some examples of the present invention, the mobile platform is arranged on the microscope; and / or the semi-transparent and semi-reflective mirror is arranged on the objective lens of the microscope; and / or the microfluidic in-situ pH measurement system also includes: a computer, the computer is connected to the camera device and the laser spectrometer; and / or the microfluidic in-situ pH measurement system also includes: a back pressure valve and a sampling container, the back pressure valve is connected to the sampling container and the microfluidic chip.

[0012] In some examples of the present invention, the microfluidic chip is constructed as a glass etched chip or a chip containing vertical through-going gaps; and / or, the spectral wavelength range generated by the laser light source includes a near-ultraviolet to visible light wavelength range.

[0013] The measurement method of the microfluid in-situ pH measurement system according to the present invention comprises the above-mentioned microfluid in-situ pH measurement system, and the measurement method comprises: calibrating the microfluid in-situ pH measurement system; and measuring the in-situ pH of the microfluid to be measured.

[0014] According to the measurement method of the microfluid in-situ pH measurement system of the present invention, by coupling a spectral pH measurement module in a microfluidic control system, the in-situ pH of the microfluid to be measured can be reliably and accurately measured, and the time and spatial distribution of the in-situ pH of the microfluid to be measured can be obtained, which solves the problem that there is currently no device that can measure the in-situ pH of the microfluid to be measured.

[0015] In some examples of the present invention, the calibration of the microfluidic in-situ pH measurement system includes: placing a pH buffer solution into the first container, placing a pH buffer solution containing an acid-base indicator into the second container; injecting the liquid in the first container into the microfluidic chip; emitting laser light through the laser light source, receiving the laser light through the laser spectrometer and obtaining a reference spectrum; injecting the liquid in the second container into the microfluidic chip; measuring the absorbance of the liquid in the microfluidic chip at a characteristic wavelength λ1 and the absorbance at characteristic wavelength λ2 Measure the absorbance of multiple pH buffers containing acid-base indicators at characteristic wavelength λ1 and the absorbance at characteristic wavelength λ2 And according to the formula Obtain pH and absorbance and The relationship between

[0016] in, Where K is the acid-base indicator ionization equilibrium constant, γ A With γ B are the activity coefficients of acid A and base B after the acid-base indicator is ionized, It is the absorbance of different pH buffers containing acid-base indicators at the characteristic wavelength Y of the acid-base indicator under condition X, where X is an extremely acidic or alkaline condition, where extremely acidic means that the pH is less than the minimum value of the indicator's color development range, and extremely alkaline means that the pH is greater than the maximum value of the indicator's color development range, and Y is the characteristic wavelength λ1 or λ2.

[0017] In some examples of the present invention, the calibration of the microfluidic in-situ pH measurement system further includes: according to the formula pK′ is pressure corrected, where R is the molar gas constant in J / (mol*K), T is the temperature in Kelvin, P is the experimental pressure, P0 is the atmospheric pressure, and ΔV 0 Δk is the change in the molar volume of the substance during the reaction under standard conditions, 0 It is the change in the molar isothermal compressibility of a substance during the reaction under standard conditions.

[0018] In some examples of the present invention, the in-situ pH measurement of the microfluid to be measured includes: placing the experimental solution into the first container, placing the experimental solution containing the acid-base indicator into the second container; injecting the liquid in the first container into the microfluidic chip; emitting laser light through the laser light source, receiving the laser light through the laser spectrometer and obtaining a reference spectrum; injecting the liquid in the second container into the microfluidic chip; measuring the absorbance of the liquid in the microfluidic chip at the characteristic wavelength λ1 and the absorbance at characteristic wavelength λ2 And obtain the in-situ pH of the experimental solution based on the calibrated data.

[0019] In some examples of the present invention, the measuring of the in-situ pH of the microfluid to be tested also includes: after obtaining the in-situ pH of the experimental solution based on the calibrated data, observing different positions of the microfluidic chip and measuring the in-situ pH at different positions to obtain the temporal and spatial distribution of the in-situ pH of the experimental solution.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0022] Figure 1 is a schematic diagram of a microfluidic in-situ pH measurement system according to an embodiment of the present invention;

[0023] Figure 2 It is a partial schematic diagram of the microfluid in-situ pH measurement system according to an embodiment of the present invention (reactor cover, reactor body, reactor support and microfluidic chip);

[0024] Figure 3 is a schematic diagram of a path of a laser according to an embodiment of the present invention;

[0025] Figure 4 4 is a flow chart of a measurement method of a microfluidic in-situ pH measurement system according to an embodiment of the present invention.

[0026] Reference numerals:

[0027] Microfluidic in-situ pH measurement system 200;

[0028] Microfluidic chip 1; temperature control device 3; reactor bracket 4; confining pressure pump 5; confining pressure fluid container 6; first container 7; second container 8; injection pump 9; injection fluid container 10; back pressure valve 11; sampling container 12; pressure sensor 13; reactor cover 21; top screw 22; reactor body 23; first window 24; second window 25; first ferrule joint 26; second ferrule joint 27; third ferrule joint 28; laser 30;

[0029] Camera device 50; microscope light source 51; objective lens 52; semi-transparent and semi-reflective mirror 53; microscope 54; moving platform 55; computer 60; laser light source 70; first optical fiber 71; first collimator 72; second collimator 73; second optical fiber 74; laser spectrometer 75;

[0030] The first pipeline 80; the second pipeline 81; the third pipeline 82; the fourth pipeline 83; the first three-way 84; the fifth pipeline 85; the sixth pipeline 86; the seventh pipeline 87; the second three-way 88; the eighth pipeline 89; the ninth pipeline 90; the third three-way 91; the tenth pipeline 92; the eleventh pipeline 93; the twelfth pipeline 94; the thirteenth pipeline 95;

[0031] a first valve 96 ; a second valve 97 ; a third valve 98 ; a fourth valve 99 ; a fifth valve 100 ; a sixth valve 101 ; a seventh valve 102 ; an eighth valve 103 ; a ninth valve 104 ; a tenth valve 105 ; an eleventh valve 106 ; and a twelfth valve 107 . DETAILED DESCRIPTION

[0032] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0033] Reference below Figure 1-Figure 3 A microfluidic in-situ pH measurement system 200 according to an embodiment of the present invention is described.

[0034] like Figure 1-Figure 3 As shown, the microfluidic in-situ pH measurement system 200 according to an embodiment of the present invention includes: a reactor bracket 4, a reactor cover 21, a reactor body 23, a microfluidic chip 1, a confining pressure pump 5, a confining pressure fluid container 6, a first container 7, a second container 8, an injection pump 9, a microscope 54, a camera device 50, a microscope light source 51, a moving platform 55, a semi-transparent and semi-reflective mirror 53, a laser light source 70 and a laser spectrometer 75.

[0035] The microfluidic chip 1 is arranged in the accommodation space of the reactor body 23; the confining pressure pump 5 is connected to the confining pressure fluid container 6 and the accommodation space; the injection pump 9 is connected to the first container 7 and the second container 8, and the first container 7 and the second container 8 are connected to the microfluidic chip 1; the camera device 50, the objective lens 52 of the microscope 54, the semi-transparent and semi-reflective mirror 53, and the moving platform 55 are moved along the first direction (i.e. Figure 3 The microscope light source 51 is arranged in sequence and correspondingly, and the laser light source 70 can emit the laser 30 toward the semi-transparent and semi-reflective mirror 53, and the semi-transparent and semi-reflective mirror 53 can reflect the laser 30 so that the laser 30 passes through the microfluidic chip 1 and is received by the laser spectrometer 75.

[0036] The reactor body 23 defines a storage space, and the microfluidic chip 1 is disposed in the storage space of the reactor body 23. As some embodiments of the present application, the microfluidic chip 1 is constructed as a glass etching chip or a chip with a vertical through-gap. For example, the microfluidic chip 1 is constructed as a sandstone chip with a straight crack with an opening of 50 μm. As some embodiments of the present application, the reactor cover 21 is connected to the reactor body 23 by a top screw 22.

[0037] The confining pressure pump 5 is connected to the confining pressure fluid container 6, and the confining pressure pump 5 is connected to the accommodation space of the reactor body 23. As some embodiments of the present application, the confining pressure pump 5 is connected to the confining pressure fluid container 6 through a first pipeline 80, and the confining pressure pump 5 is connected to the accommodation space through a second pipeline 81. As some embodiments of the present application, a first ferrule joint 26 is provided between the second pipeline 81 and the reactor body 23, so that the second pipeline 81 forms a sealed connection with the accommodation space. As some embodiments of the present application, a second ferrule joint 27 is provided between the microfluidic chip 1 and the eleventh pipeline 93, so that the eleventh pipeline 93 forms a sealed connection with the accommodation space.

[0038] As some embodiments of the present application, the microfluidic in-situ pH measurement system 200 further includes an injection fluid container 10 , and the injection pump 9 is connected to the injection fluid container 10 via a third pipeline 82 .

[0039] As some embodiments of the present application, a first valve 96 and a second valve 97 are provided on the first pipeline 80. By providing the first valve 96 and the second valve 97, the on-off connection between the confining pressure pump 5 and the confining pressure fluid container 6 can be controlled, so that the confining pressure pump 5 and the confining pressure fluid container 6 are selectively connected.

[0040] As some embodiments of the present application, a third valve 98 and a fourth valve 99 are provided on the second pipeline 81. By providing the third valve 98 and the fourth valve 99, the on-off connection between the confining pressure pump 5 and the accommodating space can be controlled, so that the confining pressure pump 5 and the accommodating space are selectively connected.

[0041] As some embodiments of the present application, the confining pressure fluid container 6 is a high-pressure gas cylinder, and the confining pressure fluid is nitrogen. Such a configuration can improve the stability of the microfluidic in-situ pH measurement system 200.

[0042] As some embodiments of the present application, the injection fluid container 10 is a liquid container, and the injection fluid is deionized water. Such a configuration can improve the stability of the microfluidic in-situ pH measurement system 200.

[0043] As some embodiments of the present application, a fifth valve 100 is provided on the third pipeline 82. By providing the fifth valve 100, the on-off connection between the injection pump 9 and the injection fluid container 10 can be controlled, so that the injection pump 9 and the injection fluid container 10 are selectively connected.

[0044] The injection pump 9 is connected to both the first container 7 and the second container 8, that is, the injection pump 9 is connected to the first container 7, and the injection pump 9 is connected to the second container 8. As some embodiments of the present application, the injection pump 9 includes an injection pump inlet and an injection pump outlet, the first container 7 includes a first container inlet and a first container outlet, the second container 8 includes a second container inlet and a second container outlet, and the microfluidic in-situ pH measurement system 200 also includes a first tee 84, the injection pump outlet is connected to the first interface of the first tee 84 through a fourth pipeline 83, the second interface of the first tee 84 is connected to the first container inlet through a fifth pipeline 85, and the third interface of the first tee 84 valve is connected to the second container inlet through a sixth pipeline 86.

[0045] As some embodiments of the present application, a sixth valve 101 is installed on the fourth pipeline 83. By setting the sixth valve 101, the on-off connection between the injection pump 9 and the first container 7 and the second container 8 can be controlled, so that the injection pump 9 is selectively connected to the first container 7 and the second container 8.

[0046] As some embodiments of the present application, a seventh valve 102 is provided on the fifth pipeline 85 to control the connection and disconnection between the first container 7 and the injection pump 9, and an eighth valve 103 is provided on the sixth pipeline 86 to control the connection and disconnection between the second container 8 and the injection pump 9.

[0047] The first container 7 and the second container 8 are both connected to the microfluidic chip 1, that is, the microfluidic chip 1 is connected to the first container 7, and the microfluidic chip 1 is connected to the second container 8. As some embodiments of the present application, the microfluidic in-situ pH measurement system 200 also includes a second tee 88, a third tee 91 and a pressure sensor 13. The outlet of the first container is connected to the fourth interface of the second tee 88 through the seventh pipeline 87, the outlet of the second container 8 is connected to the fifth interface of the second tee 88 through the eighth pipeline 89, the sixth interface of the second tee 88 is connected to the seventh interface of the third tee 91 through the ninth pipeline 90, the eighth interface of the third tee 91 is connected to the pressure sensor 13 through the tenth pipeline 92, and the ninth interface of the third tee 91 is connected to the microfluidic chip 1 through the eleventh pipeline 93, that is, the first container 7 and the second container 8 are both connected to the microfluidic chip 1.

[0048] As some embodiments of the present application, an eleventh valve 106 is provided on the eleventh pipeline 93, and a ninth valve 104 is provided on the seventh pipeline 87. By providing the ninth valve 104 and the eleventh valve 106, the connection and disconnection between the first container 7 and the accommodating space can be controlled. A tenth valve 105 is provided on the eighth pipeline 89. By providing the tenth valve 105 and the eleventh valve 106, the connection and disconnection between the second container 8 and the accommodating space can be controlled.

[0049] The camera device 50, the objective lens 52 of the microscope 54, the semi-transparent and semi-reflective mirror 53, and the moving platform 55 are arranged along a first direction (i.e. Figure 3 In the Z direction shown in the figure), they are arranged in sequence and arranged accordingly. Specifically, along the first direction (i.e. Figure 3 The semi-transparent and semi-reflective mirror 53 is fixed below the objective lens 52 of the microscope 54 and can move with the objective lens 52 of the microscope 54. The camera device 50 is arranged above the objective lens 52 of the microscope 54, and the mobile platform 55 is arranged below the semi-transparent and semi-reflective mirror 53, and the mobile platform 55 can be linked with the objective lens 52 of the microscope 54, that is, the mobile platform 55 can move with the movement of the objective lens 52 of the microscope 54. As some embodiments of the present application, the semi-transparent and semi-reflective mirror 53 and the first direction (i.e. Figure 3 The microscope light source 51 is arranged at 45 degrees in the Z direction as shown, and is disposed on a movable platform 55.

[0050] The laser light source 70 can emit the laser 30 toward the semi-transparent and semi-reflective mirror 53. As some embodiments of the present application, the laser light source 70 can emit the laser 30 along the second direction (i.e. Figure 3 The laser 30 is emitted toward the semi-transparent and semi-reflective mirror 53 (in the X direction shown in the figure). The semi-transparent and semi-reflective mirror 53 can reflect the laser 30 so that the laser 30 is emitted to the microfluidic chip 1 and then received by the laser spectrometer 75.

[0051] As some embodiments of the present application, the microfluidic in-situ pH measurement system 200 also includes a computer 60, and the camera device 50 is connected to the computer 60 via a first data line to collect image information in real time through the camera device 50. As some embodiments of the present application, the camera device 50 can be a high-speed camera.

[0052] As some embodiments of the present application, the laser spectrometer 75 is connected to the computer 60 via a second data line to collect spectral information in real time.

[0053] As some embodiments of the present application, the fluid in the confining pressure fluid container 6 may be gas, or the fluid in the confining pressure fluid container 6 may be liquid.

[0054] When measuring the in-situ pH of the microfluid to be measured, the microfluid in-situ pH measurement system 200 may be calibrated first, and then the in-situ pH of the microfluid to be measured may be measured.

[0055] As some embodiments of the present application, in the process of calibrating the microfluidic in-situ pH measurement system 200, the pH buffer solution can be first placed in the first container 7, and the pH buffer solution containing the acid-base indicator can be placed in the second container 8. Then, the liquid in the first container 7 is injected into the microfluidic chip 1, and the laser light source 70 emits the laser 30, and the laser spectrometer 75 receives the laser 30 and obtains the reference spectrum. Then, the liquid in the second container 8 is injected into the microfluidic chip 1, and then the absorbance of the liquid in the microfluidic chip 1 at the characteristic wavelength λ1 is measured. and the absorbance at characteristic wavelength λ2 Then, the absorbance of multiple pH buffers containing acid-base indicators at characteristic wavelength λ1 was measured respectively. and the absorbance at characteristic wavelength λ2 And according to the formula Obtain pH and absorbance and The relationship between

[0056] in, Where K is the acid-base indicator ionization equilibrium constant, γ A With γ B are the activity coefficients of acid A and base B after the acid-base indicator is ionized, is the absorbance of different pH buffers containing acid-base indicators at the characteristic wavelength Y of the acid-base indicator under condition X, where X is an extremely acidic or alkaline condition, where extremely acidic means that the pH is less than the minimum value of the indicator's color development range, and extremely alkaline means that the pH is greater than the maximum value of the indicator's color development range, and Y is the characteristic wavelength λ1 or λ2, and, according to the formula pK′ is pressure corrected, where R is the molar gas constant in J / (mol*K), T is the temperature in Kelvin, P is the experimental pressure, P0 is the atmospheric pressure, and ΔV 0 Δk is the change in the molar volume of the substance during the reaction under standard conditions, 0 It is the change in the molar isothermal compressibility of a substance during the reaction under standard conditions.

[0057] As some embodiments of the present application, in the process of measuring the in-situ pH of the microfluid to be measured, the experimental solution is placed in the first container 7, the experimental solution containing the acid-base indicator is placed in the second container 8, the liquid in the first container 7 is injected into the microfluidic chip 1, the laser light source 70 emits the laser 30, the laser spectrometer 75 receives the laser 30 and obtains the reference spectrum, then, the liquid in the second container 8 is injected into the microfluidic chip 1, and then, the absorbance of the liquid in the microfluidic chip 1 at the characteristic wavelength λ1 is measured. and the absorbance at characteristic wavelength λ2 After obtaining the in-situ pH of the experimental solution according to the calibrated data, observe different positions of the microfluidic chip 1 and measure the in-situ pH at different positions to obtain the temporal and spatial distribution of the in-situ pH of the experimental solution.

[0058] Therefore, the present application obtains a microfluidic in-situ pH measurement system 200 by coupling a spectroscopic pH measurement module in a microfluidic control system, which can reliably and accurately measure the in-situ pH of the microfluid to be measured, and can obtain the time and spatial distribution of the in-situ pH of the microfluid to be measured, thereby solving the problem that there is currently no device that can measure the in-situ pH of the microfluid to be measured.

[0059] In some embodiments of the present invention, Figure 1 and Figure 3 As shown, the microfluidic in-situ pH measurement system 200 further includes: a first collimator 72 and a second collimator 73, along the second direction (ie Figure 3 The first collimator 72 is disposed on one side of the semi-transparent and semi-reflective mirror 53, the second collimator 73 is disposed on the movable platform 55, the laser light source 70 is connected to the first collimator 72, the laser spectrometer 75 is connected to the second collimator 73, the laser light 30 emitted by the laser light source 70 passes through the first collimator 72 and is projected to the semi-transparent and semi-reflective mirror 53, and the laser light 30 passes through the microfluidic chip 1 and is projected to the second collimator 73, wherein the second direction is perpendicular to the first direction.

[0060] By making the microfluidic in-situ pH measurement system 200 further include the first collimator 72 and the second collimator 73, the laser light source 70 can be coupled into the required device with greater efficiency, thereby improving the measurement accuracy of the microfluidic in-situ pH measurement system 200.

[0061] In some embodiments of the present invention, Figure 1 As shown, the microfluid in-situ pH measurement system 200 also includes: a first optical fiber 71 and a second optical fiber 74 , the laser light source 70 is connected to the first collimator 72 through the first optical fiber 71 , and the laser spectrometer 75 is connected to the second collimator 73 through the second optical fiber 74 .

[0062] By connecting the laser light source 70 to the first collimator 72 through the first optical fiber 71 and connecting the laser spectrometer 75 to the second collimator 73 through the second optical fiber 74, the laser 30 can be transmitted in the optical fiber, which can reduce the loss of the laser 30 during the propagation process, and is beneficial to improving the reliability of the microfluidic in-situ pH measurement system 200.

[0063] In some embodiments of the present invention, Figure 2 As shown, the reactor cover 21 has a first viewing window 24 , the reactor body 23 has a second viewing window 25 , the first viewing window 24 is located between the microfluidic chip 1 and the semi-transparent and semi-reflective mirror 53 , and the second viewing window 25 is located between the microfluidic chip 1 and the second collimator 73 .

[0064] By locating the first window 24 between the microfluidic chip 1 and the semi-transparent mirror 53 and the second window 25 between the microfluidic chip 1 and the second collimator 73, the laser 30 can pass through the reactor cover 21 and the reactor body 23, which is beneficial to improving the rationality of the microfluidic in-situ pH measurement system 200.

[0065] In some embodiments of the present invention, Figure 2 As shown, the microfluid in-situ pH measurement system 200 further includes: a temperature control device 3 , and the reactor body 23 is arranged in the temperature control device 3 .

[0066] The measured temperature can be ensured by the temperature control device 3. As some embodiments of the present application, the temperature control device 3 increases the temperature by heating with a thermal resistor. As some embodiments of the present application, the temperature control device 3 realizes high and low temperature control by circulating oil bath or water bath.

[0067] This setup enables testing of the in situ pH of microfluidics under different temperature conditions.

[0068] In some embodiments of the present invention, Figure 1 As shown, the movable platform 55 is arranged on the microscope 54. In this way, when the position of the microscope 54 is adjusted, the relative position of the microscope 54 and the movable platform 55 will not change, which is conducive to ensuring the accuracy of the relative position of the objective lens 52 of the microscope 54 and the movable platform 55.

[0069] In some embodiments of the present invention, Figure 1As shown, the semi-transparent and semi-reflective mirror 53 is arranged on the objective lens 52 of the microscope 54. Such an arrangement is helpful to ensure the accuracy of the relative position between the objective lens 52 of the microscope 54 and the moving platform 55 when adjusting the position of the microscope 54.

[0070] In some embodiments of the present invention, Figure 1 As shown, the microfluid in-situ pH measurement system 200 also includes: a computer 60, which is connected to the camera 50 and the laser spectrometer 75. As some embodiments of the present application, the camera 50 is connected to the computer 60 via a first data line to collect image information in real time through the camera 50, and the laser spectrometer 75 is connected to the computer 60 via a second data line to collect spectral information in real time. In this way, it is convenient to calculate and observe the in-situ pH of the microfluid on the computer, which can significantly increase the measurement accuracy and real-time performance of the microfluid in-situ pH measurement system 200, and is conducive to improving the reliability of the microfluid in-situ pH measurement system 200.

[0071] In some embodiments of the present invention, Figure 1 As shown, the microfluidic in-situ pH measurement system 200 also includes: a back pressure valve 11, a sampling container 12, and the back pressure valve 11 is connected to the sampling container 12 and the microfluidic chip 1. As some embodiments of the present application, the back pressure valve 11 is connected to the microfluidic chip 1 through the twelfth pipeline 94, and the back pressure valve 11 is connected to the sampling container 12 through the thirteenth pipeline 95. As some embodiments of the present application, the twelfth pipeline 94 is provided with a twelfth valve 107 to control the on-off of the back pressure valve 11 and the reactor 4. As some embodiments of the present application, the twelfth pipeline 94 between the microfluidic chip 1 and the back pressure valve 11 is sealed and connected to the reactor body 23 through the third ferrule joint 28.

[0072] Such a configuration can adjust the pressure in the reactor body 23 through the back pressure valve 11, facilitate the discharge of the fluid medium from the reactor body 23, improve the accuracy of the microfluidic in-situ pH measurement system 200, and help improve the reliability of the use of the microfluidic in-situ pH measurement system 200. The sampling container 12 can collect the sample for subsequent analysis of the sample and avoid contamination of the sample to the outside world.

[0073] In some embodiments of the present invention, the microfluidic chip 1 is constructed as a glass-etched chip or a chip containing vertical through-spaces; and / or, the spectral wavelength range generated by the laser light source 70 includes the near-ultraviolet to visible light wavelength range.

[0074] By constructing the microfluidic chip 1 as a glass-etched chip or a chip with vertical through-gaps, the laser 30 reflected by the semi-transparent and semi-reflective mirror 53 can pass through the microfluidic chip 1 to be received by the laser spectrometer 75, which is beneficial to the rationality of the microfluidic in-situ pH measurement system 200.

[0075] As some embodiments of the present application, the diameter of the laser 30 is less than 50 μm, so that the laser 30 can pass through the cracks in the microfluidic chip 1, reducing the probability of the laser 30 being blocked, which is beneficial to improving the rationality of the microfluidic in-situ pH measurement system 200.

[0076] As some embodiments of the present application, the beam spot diameter of the laser 30 is adjustable between 1 μm and 100 μm.

[0077] Such an arrangement can realize the measurement of the pH of microfluids in pores of different sizes, which is beneficial to improving the rationality and flexibility of the microfluid in-situ pH measurement system 200.

[0078] Figure 4 : is a flow chart of a measurement method of a microfluidic in-situ pH measurement system according to an embodiment of the present invention. The microfluidic in-situ pH measurement system of the above embodiment can implement the measurement method of the microfluidic in-situ pH measurement system, such as Figure 4 As shown, the measurement method of the microfluidic in-situ pH measurement system includes the following steps:

[0079] S1, calibration of microfluidic in situ pH measurement system;

[0080] Among them, the measurement method of the microfluidic in-situ pH measurement system of the present application is combined with a temperature control device, a confining pressure pump and an injection pump to realize the measurement of the spatiotemporal distribution of the in-situ pH of the microfluid in the microfluidic chip under different temperatures and pressures. The measurement method of the microfluidic in-situ pH measurement system of the present application is explained by taking the reaction of a microfluidic chip of sandstone with a straight crack of 50 μm opening and a saturated CO2 aqueous solution under the conditions of 50°C and 10 MPa to measure the in-situ pH of the microfluidic in the microfluidic chip as an example.

[0081] As some embodiments of the present application, before measurement, it is necessary to prepare pH buffer solutions of different pH values, acid-base indicator stock solutions and saturated CO2 aqueous solutions. As some embodiments of the present application, the acid-base indicator is a bromophenol blue indicator, and the pH buffer solution is a citric acid-sodium citrate buffer solution.

[0082] The microfluidic in-situ pH measurement system is assembled and the gas in the pipeline is exhausted for measurement. By calibrating the microfluidic in-situ pH measurement system, the relevant parameters of the acid-base indicator can be obtained to facilitate the measurement of the in-situ pH of the microfluid to be measured.

[0083] S2, measure the in situ pH of the microfluid to be tested.

[0084] By measuring the in-situ pH of the microfluid to be tested at multiple points, a spatiotemporal distribution diagram of the in-situ pH of the microfluid to be tested can be obtained.

[0085] Therefore, the present application can reliably and accurately measure the in-situ pH of the microfluid to be tested, and can obtain the time and spatial distribution of the in-situ pH of the microfluid to be tested, by coupling a spectroscopic pH measurement module in a microfluid control system, thereby solving the problem that there is currently no device that can measure the in-situ pH of the microfluid to be tested.

[0086] In some embodiments of the present invention, calibrating a microfluidic in-situ pH measurement system comprises:

[0087] S11, placing a pH buffer solution into a first container, and placing a pH buffer solution containing an acid-base indicator into a second container;

[0088] Specifically, the pH buffer solution is placed in the first container, the pH buffer solution with an appropriate amount of acid-base indicator solution added thereto is placed in the second container, the fifth valve, the sixth valve, the seventh valve, the ninth valve, the eleventh valve and the twelfth valve are opened to connect the injection pump, the first container, the reactor and the back pressure valve, and the back pressure valve is adjusted to 0 MPa.

[0089] S12, injecting the liquid in the first container into the microfluidic chip;

[0090] Start the injection pump, inject pH buffer without acid-base indicator into the microfluidic chip through the first container, fill the pores in the microfluidic chip with pH buffer without acid-base indicator, then close the injection pump, turn on the temperature control device to make the temperature in the reactor reach 50°C.

[0091] S13, emitting laser light through a laser light source, receiving the laser light through a laser spectrometer and acquiring a reference spectrum;

[0092] Turn on the laser light source, adjust the objective lens of the microscope, select the measurement point, and the laser passes through the first optical fiber and the first collimator along the second direction (i.e. Figure 3 The X direction shown in the figure) is horizontally directed to the half-transparent and half-reflective mirror set at 45 degrees, and then turns to the first direction (i.e. Figure 3 The reflected laser is directed vertically downward (in the Z direction shown), and then passes through the first window, the microfluidic chip, and the second window in sequence, and is received by the second collimator. It is then received by the laser spectrometer through the second optical fiber to obtain a reference spectrum.

[0093] S14, injecting the liquid in the second container into the microfluidic chip;

[0094] Specifically, the seventh valve and the ninth valve are closed, and the eighth valve and the tenth valve are opened to connect the injection pump, the second container and the reactor, the injection pump is started, and the pH buffer solution containing the acid-base indicator is injected into the microfluidic chip through the second container. After the pores in the microfluidic chip are filled with the pH buffer solution containing the acid-base indicator, the injection pump is closed.

[0095] S15, measuring the absorbance of the liquid in the microfluidic chip at the characteristic wavelength λ1 and the absorbance at characteristic wavelength λ2

[0096] S16, respectively measure the absorbance of multiple pH buffers containing acid-base indicators at characteristic wavelength λ1 and the absorbance at characteristic wavelength λ2 And according to the formula Obtain pH and absorbance and The relationship between

[0097] in, Where K is the acid-base indicator ionization equilibrium constant, γ A With γ B are the activity coefficients of acid A and base B after the acid-base indicator is ionized, It is the absorbance of different pH buffers containing acid-base indicators at the characteristic wavelength Y of the acid-base indicator under condition X, where X is an extremely acidic or alkaline condition, where extremely acidic means that the pH is less than the minimum value of the indicator's color development range, and extremely alkaline means that the pH is greater than the maximum value of the indicator's color development range, and Y is the characteristic wavelength λ1 or λ2.

[0098] In some embodiments of the present invention, Figure 1-Figure 3 As shown, the calibration microfluidic in-situ pH measurement system also includes:

[0099] According to the formula pK′ is pressure corrected, where R is the molar gas constant in J / (mol*K), T is the temperature in Kelvin, P is the experimental pressure, P0 is the atmospheric pressure, and ΔV 0 Δk is the change in the molar volume of the substance during the reaction under standard conditions, 0 It is the change in the molar isothermal compressibility of a substance during the reaction under standard conditions.

[0100] It should be noted that after the calibration, the pipes in the microfluidic in-situ pH measurement system need to be cleaned to reduce the impact of liquid residue on the measurement, which is beneficial to improve the accuracy of the measurement.

[0101] In some embodiments of the present invention, measuring the in-situ pH of a microfluid to be tested comprises:

[0102] S21, placing the experimental solution into the first container, and placing the experimental solution containing the acid-base indicator into the second container;

[0103] As some embodiments of the present application, the first valve, the second valve, the third valve and the fourth valve are first opened to connect the confining pressure fluid container, the confining pressure pump and the reactor, the confining pressure pump is turned on, and the confining pressure in the reactor is controlled to 13 MPa. The temperature control device is turned on to control the temperature in the reactor to 50°C, and a saturated CO2 aqueous solution without an acid-base indicator is placed in the first container, and a saturated CO2 aqueous solution containing an acid-base indicator is placed in the second container.

[0104] S22, injecting the liquid in the first container into the microfluidic chip;

[0105] As some embodiments of the present application, the fifth valve, the sixth valve, the seventh valve, the ninth valve, the eleventh valve, and the twelfth valve are opened to connect the injection pump, the first container, the reactor, and the back pressure valve. The back pressure valve is adjusted to 9.9 MPa, the injection pump is started, and a saturated CO2 aqueous solution without an acid-base indicator is injected into the microfluidic chip through the first container so that the pores in the microfluidic chip are filled with a saturated CO2 aqueous solution without an acid-base indicator, and then the injection pump is closed.

[0106] S23, emitting laser light through a laser light source, receiving the laser light through a laser spectrometer and acquiring a reference spectrum;

[0107] Turn on the laser light source, adjust the objective lens of the microscope, select the measurement point, and the laser passes through the first optical fiber and the first collimator along the second direction (i.e. Figure 3 The X direction shown in the figure) is horizontally directed to the half-transparent and half-reflective mirror set at 45 degrees, and then turns to the first direction (i.e. Figure 3 The reflected laser is directed vertically downward (in the Z direction shown), and then passes through the first through hole, the microfluidic chip, and the second through hole in sequence, and is received by the second collimator, and then is received by the laser spectrometer through the second optical fiber to obtain a reference spectrum.

[0108] S24, injecting the liquid in the second container into the microfluidic chip;

[0109] As some embodiments of the present application, the seventh valve and the ninth valve are closed, and the eighth valve and the tenth valve are opened to connect the injection pump, the second container and the reactor, the injection pump is started, and a saturated CO2 aqueous solution containing an acid-base indicator is injected into the microfluidic chip at a constant flow rate through the second container so that the upstream pressure of the microfluidic chip does not exceed 10 MPa.

[0110] S25, measure the absorbance of the liquid in the microfluidic chip at the characteristic wavelength λ1 and the absorbance at characteristic wavelength λ2 And obtain the in-situ pH of the experimental solution based on the calibrated data.

[0111] By adjusting the objective lens of the microscope, the measurement point is selected and the absorbance of the liquid in the microfluidic chip at the characteristic wavelength λ1 is measured. and the absorbance at characteristic wavelength λ2 And obtain the in-situ pH of the experimental solution based on the calibrated data.

[0112] Therefore, by coupling a laser spectrometer with a microscope, the in situ pH of microfluidics can be measured reliably and accurately.

[0113] In some examples of the present invention, measuring the in-situ pH of the microfluid to be tested also includes: after obtaining the in-situ pH of the experimental solution based on calibrated data, observing different positions of the microfluidic chip and measuring the in-situ pH at different positions to obtain the temporal and spatial distribution of the in-situ pH of the experimental solution.

[0114] Thus, the temporal and spatial distribution of the in-situ pH value of the microfluid to be tested can be obtained, which solves the problem that there is currently no device capable of measuring the in-situ pH value of the microfluid to be tested.

[0115] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0116] In the description of the present invention, "first feature" or "second feature" may include one or more of the features.

[0117] In the description of the present invention, "plurality" means two or more.

[0118] In the description of the present invention, a first feature being “on” or “under” a second feature may include that the first and second features are directly in contact with each other, or may include that the first and second features are not in direct contact with each other but are in contact with each other via another feature therebetween.

[0119] In the description of the present invention, “on”, “over” and “above” a first feature from a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0120] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0121] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A microfluidic in-situ pH measurement system, characterized in that: include: A reactor body, a reactor cover, and a microfluidic chip, wherein the microfluidic chip is arranged in the accommodating space of the reactor body; A confining pressure pump and a confining pressure fluid container, wherein the confining pressure pump is connected to the confining pressure fluid container and the containing space; A first container, a second container, and an injection pump, wherein the injection pump is connected to the first container and the second container, and the first container and the second container are connected to the microfluidic chip; A microscope, an imaging device, a microscope light source, a mobile platform, and a semi-transparent and semi-reflective mirror, wherein the imaging device, the objective lens of the microscope, the semi-transparent and semi-reflective mirror, and the mobile platform are sequentially arranged and correspondingly disposed along a first direction, and the microscope light source is disposed on the mobile platform; A laser light source and a laser spectrometer, wherein the laser light source can emit laser light toward the semi-transparent and semi-reflective mirror, and the semi-transparent and semi-reflective mirror can reflect the laser light so that the laser light passes through the microfluidic chip and is received by the laser spectrometer.

2. The microfluidic in-situ pH measurement system according to claim 1, characterized in that: Also includes: A first collimator and a second collimator are arranged along a second direction, wherein the first collimator is arranged on one side of the semi-transparent and semi-reflective mirror, and the second collimator is arranged on the movable platform. The laser light source is connected to the first collimator, and the laser spectrometer is connected to the second collimator. The laser emitted by the laser light source passes through the first collimator and is directed to the semi-transparent and semi-reflective mirror, and the laser passes through the microfluidic chip and is directed to the second collimator, wherein the second direction is perpendicular to the first direction.

3. The microfluidic in-situ pH measurement system according to claim 2, characterized in that: Also includes: a first optical fiber and a second optical fiber, the laser light source and the first collimator are connected through the first optical fiber, and the laser spectrometer and the second collimator are connected through the second optical fiber.

4. The microfluidic in-situ pH measurement system according to claim 2, characterized in that: The reactor cover has a first viewing window, and the reactor body has a second viewing window. The first viewing window is located between the microfluidic chip and the semi-transparent and semi-reflective mirror, and the second viewing window is located between the microfluidic chip and the second collimator.

5. The microfluidic in-situ pH measurement system according to claim 1, characterized in that: Also includes: A temperature control device, wherein the reactor body is arranged in the temperature control device.

6. The microfluidic in-situ pH measurement system according to claim 1, characterized in that: The mobile platform is arranged on the microscope; And / or, the semi-transparent and semi-reflective mirror is arranged on the objective lens of the microscope; And / or, the microfluid in-situ pH measurement system further comprises: a computer, wherein the computer is connected to the camera device and the laser spectrometer; And / or, the microfluidic in-situ pH measurement system further includes: a back pressure valve and a sampling container, and the back pressure valve is connected to the sampling container and the microfluidic chip.

7. The microfluidic in-situ pH measurement system according to claim 1, characterized in that: The microfluidic chip is constructed as a glass etched chip or a chip containing vertically penetrating gaps; And / or, the spectral wavelength range generated by the laser light source includes the near-ultraviolet to visible light wavelength range.

8. A measurement method for a microfluidic in-situ pH measurement system, characterized in that: The microfluidic in-situ pH measurement system is a microfluidic in-situ pH measurement system according to any one of claims 1 to 7, and the measurement method comprises: calibrating the microfluidic in-situ pH measurement system; Measure the pH of the microfluid in situ.

9. The measurement method of the microfluidic in-situ pH measurement system according to claim 8, characterized in that: The calibration of the microfluidic in-situ pH measurement system comprises: Placing a pH buffer solution into the first container, and placing a pH buffer solution containing an acid-base indicator into the second container; Injecting the liquid in the first container into the microfluidic chip; The laser light source emits laser light, and the laser spectrometer receives the laser light and obtains a reference spectrum; injecting the liquid in the second container into the microfluidic chip; Measure the absorbance of the liquid in the microfluidic chip at the characteristic wavelength λ1 and the absorbance at characteristic wavelength λ2 Measure the absorbance of multiple pH buffers containing acid-base indicators at characteristic wavelength λ1 and the absorbance at characteristic wavelength λ2 And according to the formula Obtain pH and absorbance and The relationship between in, Where K is the acid-base indicator ionization equilibrium constant, γ A With γ B are the activity coefficients of acid A and base B after the acid-base indicator is ionized, It is the absorbance of different pH buffers containing acid-base indicators at the characteristic wavelength Y of the acid-base indicator under condition X, where X is an extremely acidic or alkaline condition, where extremely acidic means that the pH is less than the minimum value of the indicator's color development range, and extremely alkaline means that the pH is greater than the maximum value of the indicator's color development range, and Y is the characteristic wavelength λ1 or λ2.

10. The measurement method of the microfluidic in-situ pH measurement system according to claim 9, characterized in that: The calibration of the microfluidic in-situ pH measurement system also includes: According to the formula pK′ is pressure corrected, where R is the molar gas constant in J / (mol*K), T is the temperature in Kelvin, P is the experimental pressure, P0 is the atmospheric pressure, and ΔV 0 Δk is the change in the molar volume of the substance during the reaction under standard conditions, 0 It is the change in the molar isothermal compressibility of a substance during the reaction under standard conditions.

11. The measurement method of the microfluidic in-situ pH measurement system according to claim 8, characterized in that: The in-situ pH measurement of the microfluid to be measured comprises: Placing the experimental solution into the first container, and placing the experimental solution containing the acid-base indicator into the second container; Injecting the liquid in the first container into the microfluidic chip; The laser light source emits laser light, and the laser spectrometer receives the laser light and obtains a reference spectrum; injecting the liquid in the second container into the microfluidic chip; Measure the absorbance of the liquid in the microfluidic chip at the characteristic wavelength λ1 and the absorbance at characteristic wavelength λ2 And obtain the in-situ pH of the experimental solution based on the calibrated data.

12. The measurement method of the microfluidic in-situ pH measurement system according to claim 11, characterized in that: The measuring of the in-situ pH of the microfluid to be tested also includes: after obtaining the in-situ pH of the experimental solution according to the calibrated data, observing different positions of the microfluidic chip and measuring the in-situ pH at different positions to obtain the time and space distribution of the in-situ pH of the experimental solution.

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