Capillary tube packaging system

Abstract

The invention provides a capillary tube packaging system. The capillary tube packaging system comprises an end cover, a threaded sleeve, a top cover and a capillary tube, the inner diameter of the threaded sleeve is matched with the outer diameter of the capillary tube; the end cover is in extrusion fit with the lower part of the threaded sleeve; the top cover is in extrusion fit with the upper portion of the threaded sleeve. According to the capillary packaging system provided by the invention, the near electrode area (lt; 100 microns) electrolyte is directly injected, and the spatial resolution is improved.

Description

Technical Field

[0001] The present application relates to the field of differential electrochemical mass spectrometry, and in particular to a capillary packaging system. Background Art

[0002] In the field of electrochemical research, it is necessary to conduct qualitative and quantitative testing of the products of electrochemical reactions. Currently, the commonly used product testing methods include nuclear magnetic resonance, liquid chromatography, gas chromatography, etc. The response time of these technologies is usually long, and it is difficult to characterize the substances generated and consumed near the electrode surface in real time. In order to achieve real-time monitoring of the conversion of reactants and the generation of products in the near-electrode area, many researchers are committed to the development of differential electrochemical mass spectrometry.

[0003] Differential electrochemical mass spectrometry (DEMS) uses differential injection to maintain the pressure difference between the vacuum chamber and the injection port through the front vacuum system, so as to achieve injection from the vicinity of the electrode and maintain the vacuum chamber pressure within the appropriate working pressure range of the mass spectrometer monitor (10e -6 ~10e -5 hPa). Since electrochemical reactions are usually carried out in a certain solvent (such as water), when designing a mass spectrometry injection system, a filter membrane with a certain permeability selectivity is needed to minimize the permeation of solvents (such as water) and maximize the permeation of gas phase substances (such as carbon dioxide, ethylene, etc.), reduce the pressure of the vacuum system, and improve the sensitivity of the system. The current injection method of differential electrochemical mass spectrometry is mainly to connect the differential vacuum system to the gas diffusion electrode of the electrochemical cell to achieve injection from the electrode. This injection method samples the entire electrode, cannot achieve spatial resolution, and has many restrictions on the structure of the electrochemical reaction cell. Capillary injection can improve spatial resolution and can be flexibly used in electrochemical cells of various configurations. Summary of the invention

[0004] The purpose of the present application is to provide a capillary packaging system to achieve direct sampling in the electrolyte near the electrode region (<100 microns) in differential electrochemical mass spectrometry testing and improve spatial resolution.

[0005] The first aspect of the present application provides a capillary packaging system, which includes an end cover, a threaded sleeve, a top cover, a capillary and a sealing film; the inner diameter of the threaded sleeve matches the outer diameter of the capillary; the sealing film covers the pores at the lower end of the capillary; the end cover is extruded and fitted with the lower part of the threaded sleeve; the top cover is extruded and fitted with the upper part of the threaded sleeve.

[0006] The capillary packaging system of the present application can realize direct sampling in the electrolyte near the electrode area (<100 microns), which is crucial for the accurate analysis of gaseous substances produced during electrochemical reactions. It improves the accuracy and sensitivity of the test, making the test results more realistic and reliable, thereby helping researchers to have a deeper understanding of the reaction mechanism.

[0007] In some embodiments of the present application, the upper portion of the end cover is cylindrical, and the lower portion is truncated cone-shaped; the upper and lower portions of the threaded sleeve are truncated cone-shaped, and the middle portion is cylindrical; the top cover is cylindrical, and the upper portion of the top cover has a truncated cone-shaped inner cavity, and the lower portion has a cylindrical inner cavity.

[0008] In some embodiments of the present application, the upper portion of the end cap is provided with an internal thread, the middle portion of the threaded sleeve is provided with an external thread, and the lower cylindrical inner cavity of the top cap is provided with an internal thread; the external thread and the internal thread are used in combination.

[0009] In some embodiments of the present application, the inner diameter of the capillary is 0.1 μm to 0.5 μm.

[0010] In some embodiments of the present application, the sealing film has a thickness of 0.03 mm to 0.1 mm.

[0011] The second aspect of the present application provides a use of the capillary packaging system provided in the first aspect of the present application for differential electrochemical mass spectrometry sampling.

[0012] Beneficial effects of this application:

[0013] The present application provides a capillary packaging system, which can realize direct injection of electrolyte in the near-electrode region (<100 microns) in differential electrochemical mass spectrometry testing through the design of the packaging structure at the end of the capillary, thereby improving the accuracy and sensitivity of the test, and thus realizing real-time and accurate monitoring of gas products during the electrochemical reaction process, so that researchers can observe small changes and intermediate products during the reaction process and deeply understand the reaction mechanism. In addition, the use of the capillary packaging system for injection can also reduce the restrictions on the structure of the electrochemical reaction cell and broaden the scope of test applications.

[0014] Of course, implementing any product or method of the present application does not necessarily require achieving all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0016] Figure 1 This is an end cover diagram of Example 1 of the present application;

[0017] Figure 2 This is a diagram of a threaded sleeve according to Example 1 of the present application;

[0018] Figure 3 This is a top cover diagram of Example 1 of the present application;

[0019] Figures 4a to 4d A schematic diagram of the installation of a capillary packaging system according to an embodiment of the present application;

[0020] Figure 5 Schematic diagram of the DEMS testing device of Example 1 of the present application;

[0021] Figure 6a The LSV curve of the current versus voltage of the CO2 reduction reaction tested using the capillary packaging system of Example 1 of the present application;

[0022] Figure 6b A curve showing the change of the DEMS signal of the reactant in the CO2 reduction reaction tested using the capillary encapsulation system of Example 1 of the present application over time;

[0023] Figure 6c The curve is a graph showing the change of the DEMS signal of the product of the CO2 reduction reaction tested using the capillary packaging system of Example 1 of the present application over time. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the present application belong to the scope of protection of the present application.

[0025] At present, the sampling method of differential electrochemical mass spectrometry is mainly to connect the differential vacuum system with the gas diffusion electrode of the electrochemical cell to achieve sampling near the electrode. This sampling method samples the entire electrode, cannot achieve spatial resolution, and has many restrictions on the structure of the electrochemical reaction cell. Based on this, the present application provides a capillary packaging system to achieve direct sampling in the electrolyte near the electrode area (<100 microns) to improve the spatial resolution.

[0026] The first aspect of the present application provides a capillary packaging system, as shown in Figure 4, which includes an end cover 1, a threaded sleeve 2, a top cover 3, a capillary 4 and a sealing film 5; the inner diameter of the threaded sleeve 2 matches the outer diameter of the capillary 4; the sealing film 5 covers the pores at the lower end of the capillary 4; the end cover 1 is extruded and fitted with the lower part of the threaded sleeve 2; and the top cover 3 is extruded and fitted with the upper part of the threaded sleeve 2.

[0027] In differential electrochemical mass spectrometry testing, capillary sampling can improve spatial resolution and can be flexibly used in electrochemical cells of various configurations. By coating the pores at the lower end of the capillary 4 with a sealing film 5, the capillary 4 and the threaded sleeve 2 are matched, and the top cover 3 and the end cover 1 are squeezed and matched with the threaded sleeve 2, the entire capillary packaging system is liquid-tight in the electrochemical reaction cell, and direct sampling in the electrolyte near the electrode area (<100 microns) is achieved, thereby achieving real-time monitoring of the electrochemical reaction conversion process.

[0028] In some embodiments of the present application, Figures 1 to 3 As shown, the upper part of the end cover 1 is cylindrical, and the lower part is truncated cone-shaped; the upper and lower parts of the threaded sleeve 2 are truncated cone-shaped, and the middle part is cylindrical; the top cover 3 is cylindrical, and the upper part of the top cover 3 has a truncated cone-shaped inner cavity, and the lower part has a cylindrical inner cavity.

[0029] In some embodiments of the present application, Figures 1 to 3 As shown, the upper part of the end cover 1 is provided with an internal thread, the middle part of the threaded sleeve 2 is provided with an external thread, and the lower cylindrical inner cavity of the top cover 3 is provided with an internal thread; the external thread and the internal thread are used in combination.

[0030] A schematic diagram of the installation of a capillary packaging system according to an embodiment of the present application is shown in FIG. Figures 4a to 4d As shown, the inner diameter of the threaded sleeve 2 matches the outer diameter of the capillary 4, the lower part of the threaded sleeve 2 is flush with the capillary 4, and the sealing film jointly covers the pores at the lower end of the capillary 4 and the lower part of the threaded sleeve 2. The top cover 3 is screwed into the threaded sleeve, and the truncated cone-shaped inner cavity at the upper part of the top cover 3 and the upper part of the threaded sleeve 2 are squeezed against each other to achieve sealing of the solvent. The end cover 1 is screwed into the threaded sleeve 2, and the lower part of the end cover 1 and the lower part of the threaded sleeve 2 are squeezed against each other to achieve sealing of the solvent. The external thread of the threaded sleeve 2 is tightly engaged with the internal thread of the end cover 1 and the top cover 3, thereby also preventing the solvent from entering. The entire packaging structure of the capillary packaging system of the present application is liquid-tight and can be directly immersed in a solvent to achieve real-time sampling in an electrolyte.

[0031] In some embodiments of the present application, the inner diameter of the capillary is 0.1 μm to 0.5 μm. For example, the inner diameter of the capillary can be 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, or a range consisting of any two of these values. By controlling the inner diameter of the capillary within the above range, the spatial resolution of the injection can be improved and high-precision injection can be achieved.

[0032] In some embodiments of the present application, the thickness of the sealing film is 0.03 mm to 0.1 mm. For example, the thickness of the sealing film is 0.03 mm, 0.05 mm, 0.07 mm, 0.1 mm, or a range consisting of any two of these values. Controlling the thickness of the sealing film within the above range can make the capillary packaging system have higher liquid tightness.

[0033] In the present application, there is no particular limitation on the material of the sealing film, as long as the purpose of the present application can be achieved. For example, polydimethylsiloxane (PDMS) or polytetrafluoroethylene (PTFE) can be used, and the above two materials have the advantages of high toughness, good hydrophobicity and good air permeability.

[0034] In the present application, there is no particular restriction on the materials of the capillary, end cap, top cap and threaded sleeve, as long as the purpose of the present application can be achieved. For example, the material of the capillary, end cap and top cap can be polyetheretherketone (PEEK), which has high hardness and is not easy to deform; the material of the threaded sleeve can be PTFE, which has low hardness and is easy to deform to achieve sealing.

[0035] In the present application, there is no particular limitation on the outer diameter and length of the capillary, as long as the purpose of the present application can be achieved.

[0036] The second aspect of the present application provides a use of the capillary packaging system provided in the first aspect of the present application for differential electrochemical mass spectrometry sampling.

[0037] Example

[0038] The following examples and comparative examples are given to more specifically describe the embodiments of the present application. Various tests and evaluations were performed according to the following methods. In addition, unless otherwise specified, "parts" and "%" are based on mass.

[0039] Test methods and equipment:

[0040] Linear Sweep Voltammetry (LSV) Test:

[0041] The electrochemical reaction cell was subjected to a linear voltammetric scan using an electrochemical workstation, with the scan range set to -0.5 V to -2 V and the scan rate set to 1 mV / s to obtain a linear voltammetric scan curve.

[0042] Differential Electrochemical Mass Spectrometry (DEMS) Test:

[0043] The capillary packaging system prepared in Example 1 was installed in a DEMS test device and an electron bombardment ion source (electron intensity 70 eV) and a quadrupole mass spectrometer (Inficon MPH100M), the detector selected Faraday cup, the electron multiplier was not turned on, the dwell time of each sampled mass-to-charge ratio was set to 64ms, and the reactants and products of the electrochemical reaction were tested.

[0044] Example 1

[0045] <End cap design>

[0046] like Figure 1 As shown, the material of the end cap 1 is polyetheretherketone, the upper length of the end cap 1 is 5mm, the lower length is 4.5mm, the upper outer diameter of the end cap 1 is 5mm, the lower end outer diameter of the end cap 1 is 2.5mm, the lower end inner diameter of the end cap 1 is 2mm, and the internal thread on the upper part of the end cap 1 is an M4 coarse internal thread.

[0047] <Thread set design>

[0048] like Figure 2 As shown, the material of the threaded sleeve 2 is polytetrafluoroethylene, the upper and lower lengths of the threaded sleeve 2 are 5 mm, the middle length is 10 mm, the inner diameter of the threaded sleeve 2 is 1.7 mm, matching the capillary 4 with an outer diameter of 1 / 16 inch, and the external thread in the middle of the threaded sleeve 2 is an M4 coarse thread.

[0049] <Top cover design>

[0050] like Figure 3 As shown, the lengths of the upper and lower parts of the top cover 3 are both 5 mm, the outer diameter of the top cover 3 is 5 mm, the top diameter of the inner cavity of the upper part of the top cover 3 is 2 mm, and the internal thread on the inner cavity of the lower part of the top cover 3 is an M4 coarse internal thread.

[0051] <Installing the Capillary Encapsulation System>

[0052] according to Figures 4a to 4d The steps shown are to install the capillary packaging system. The inner diameter of the threaded sleeve 2 matches the outer diameter of the capillary 4, and the lower part of the threaded sleeve 2 is flush with the capillary 4. Figure 4a As shown. Figure 4b As shown, the top cover 3 is screwed into the threaded sleeve 2, so that the truncated cone-shaped inner cavity at the top of the top cover 3 and the upper part of the threaded sleeve 2 are pressed against each other. Figure 4c As shown in FIG. 1 , a PTFE membrane with a diameter of 10 mm and a thickness of 0.05 mm is coated on the pores at the lower end of the capillary 4 and the lower part of the threaded sleeve 2. The end cap 1 is screwed into the threaded sleeve 2, and the PTFE membrane is squeezed and fixed between the lower part of the end cap 1 and the lower part of the threaded sleeve 2. The external thread of the threaded sleeve 2 is tightly engaged with the internal thread of the end cap 1 and the top cap 3. The installed capillary packaging system is shown in FIG. Figure 4d shown.

[0053] like Figure 5As shown, the capillary encapsulation system of Example 1 can realize real-time detection of electrochemical reaction products, taking CO2 reduction as an example. In the figure, WE represents the working electrode (gas diffusion electrode loaded with Cu), RE represents the saturated AgCl / Ag reference electrode, CE represents the graphite counter electrode, and the capillary encapsulation system probe is close to the working electrode (<100 microns) to sample the near-electrode area. The reaction cell is subjected to a linear voltammetric scan with a scan range of -2.5V to -4.0V and a scan rate of 1mV / s. The LSV curve is shown in FIG. Figure 6a As shown, DEMS test data is as follows Figure 6b and Figure 6c As shown, the charge-to-mass ratios of 27, 28, 31, and 44 correspond to ethylene, carbon monoxide, ethanol, and carbon dioxide, respectively.

[0054] It can be seen from Example 1 that the capillary packaging system designed in the present application can realize direct injection into the electrolyte in the near-electrode region (<100 microns), thereby improving the spatial resolution.

[0055] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A capillary packaging system, comprising an end cap, a threaded sleeve, a top cap, a capillary and a sealing film; the inner diameter of the threaded sleeve matches the outer diameter of the capillary; the sealing film covers the pores at the lower end of the capillary; the end cap is extruded and fitted with the lower part of the threaded sleeve; the top cap is extruded and fitted with the upper part of the threaded sleeve.

2. The capillary packaging system according to claim 1, wherein: The upper part of the end cover is cylindrical, and the lower part is truncated cone-shaped; the upper and lower parts of the threaded sleeve are truncated cone-shaped, and the middle part is cylindrical; the top cover is cylindrical, and the upper part of the top cover has a truncated cone-shaped inner cavity, and the lower part has a cylindrical inner cavity.

3. The capillary packaging system according to claim 1, wherein: The upper part of the end cover is provided with an internal thread, the middle part of the threaded sleeve is provided with an external thread, and the lower cylindrical inner cavity of the top cover is provided with an internal thread; the external thread and the internal thread are used in combination.

4. The capillary packaging system according to claim 1, wherein: The inner diameter of the capillary is 0.1 μm to 0.5 μm.

5. The capillary packaging system according to claim 1, wherein: The thickness of the sealing film is 0.03 mm to 0.1 mm. 6 . Use of the capillary packaging system according to any one of claims 1 to 5 for differential electrochemical mass spectrometry sampling.

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