Hollow fiber flow field flow fractionation device and system

Abstract

This invention provides a hollow fiber flow field separation device and system, comprising: a separation channel having a first port, a second port, and a third port, wherein a hollow fiber membrane is embedded within the separation channel. The first port and the second port are respectively connected to a current-carrying device; the first port and the third port are also respectively connected to a detection device; a sample introduction unit adapted to introduce micro / nano particle samples into the separation channel via the current-carrying device; and a valve control unit configured to automatically switch the flow path of the current-carrying device, such that the separation channel has: a first state in which the current-carrying device flows into the hollow fiber membrane through the first port and the second port respectively, causing the micro / nano particles to focus within the hollow fiber membrane, and causing the permeate separated by the hollow fiber membrane to flow to the detection device through the third port; and a second state in which the current-carrying device flows into the separation channel through the second port to elute the micro / nano particles focused within the hollow fiber membrane, and then flows to the detection device through the first port.

Description

Technical Field

[0001] This utility model relates to the field of analytical chemistry, specifically to a hollow fiber flow field separation device and system. Background Technology

[0002] The precise separation and characterization of micro- and nanoparticles (1 nm–100 μm) is a key technological requirement in fields such as nanomaterials research and development, biomedicine, and environmental monitoring. Current mainstream analytical methods, such as dynamic light scattering, nanoparticle tracking analysis, electron microscopy, and size exclusion chromatography, have significant limitations: dynamic light scattering and nanoparticle tracking analysis require high sample concentrations and pretreatment; the porous packed columns of size exclusion chromatography are prone to clogging and have limited separation range; and electron microscopy requires sample drying and fixation, which can easily lead to changes in the properties of micro- and nanoparticles.

[0003] Flow field separation technology has a wide separation range for micro and nanoparticles (1 nm to 100 μm), and because there is no stationary phase in the channel, it can reduce damage to micro and nanoparticles during the separation process, thus showing great application potential. Existing hollow fiber flow field separation systems require manual switching of different separation stages by turning a stopcock valve, which cannot achieve precise control over different separation stages and limits the repeatability and stability of micro and nanoparticle separation. Utility Model Content

[0004] In view of this, the present invention provides a hollow fiber flow field separation device and system.

[0005] According to a first aspect of the present invention, a hollow fiber flow field separation device is provided, comprising: a separation channel having a first port, a second port opposite to the first port, and a third port close to the second port, wherein a hollow fiber membrane is embedded in the separation channel, and the first port and the second port are respectively connected to an external flow carrier device; the first port and the third port are also respectively connected to an external detection device; a sample introduction unit being connected to the second port and the external flow carrier device, the sample introduction unit being adapted to introduce a micro / nano particle sample flow into the separation channel; and a valve control unit configured to automatically switch the flow path of the flow carrier, such that the separation channel has the following two states: a first state: the flow carrier flows into the hollow fiber membrane through the first port and the second port respectively, causing the micro / nano particles to focus within the hollow fiber membrane, and the permeate separated from the hollow fiber membrane flows to the detection device through the third port; and a second state: the flow carrier flows into the separation channel through the second port to elute the micro / nano particles focused within the hollow fiber membrane, and flows to the detection device through the first port.

[0006] According to an embodiment of the present invention, the valve control unit includes: a first electric valve, adapted to be connected to a flow-carrying device and a first port respectively, so as to open the channel between the flow-carrying device and the first port in a first state.

[0007] According to an embodiment of the present invention, the first electric valve is also adapted to be connected to a detection device to close the channel between the current-carrying device and the first port in a second state, and to open the channel between the detection device and the first port.

[0008] According to an embodiment of the present invention, the valve control unit further includes: a second electric valve, adapted to be connected to the third port and the detection device respectively, so as to open the channel between the third port and the detection device in a first state.

[0009] According to an embodiment of the present invention, the second electric valve is also suitable for connection with an external waste liquid collection device to close the channel between the third port and the detection device in the second state, and to open the channel between the third port and the waste liquid collection device.

[0010] According to an embodiment of the present invention, a flow regulating valve is further provided between the second electric valve and the waste liquid collection device. The flow regulating valve is used to control the flow rate of the permeate in the second state.

[0011] According to an embodiment of the present invention, the valve control unit further includes: a third electric valve, adapted to be connected to the flow carrier and the injection unit respectively, so as to open the channel between the flow carrier and the injection unit in a first state and a second state.

[0012] According to an embodiment of the present invention, in a first state, the current carrying velocity of the first port is configured to be greater than that of the second port, so that the micro-nano particles are focused on the side near the third port.

[0013] According to another aspect of the present invention, a hollow fiber flow field separation system is also provided, comprising: the aforementioned hollow fiber flow field separation device; a current-carrying device connected to the hollow fiber flow field separation device and adapted to supply current to the hollow fiber flow field separation device; and a detection device connected to the hollow fiber flow field separation device and adapted to analyze and characterize the micro-nano particles flowing out of the hollow fiber flow field separation device in a first state and a second state.

[0014] According to an embodiment of the present invention, the flow-carrying device includes: a flow-carrying bottle for storing flow; and a plunger pump disposed between the flow-carrying bottle and the hollow fiber flow field separation device to deliver the flow to the hollow fiber flow field separation device.

[0015] According to an embodiment of this utility model, the automatic switching of the flow path of the carrier by the valve control unit realizes the automated control of the focusing stage and elution stage of micro-nano particles in the separation channel, thereby improving the repeatability and stability of micro-nano particle separation. Attached Figure Description

[0016] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the present invention with reference to the accompanying drawings, in which:

[0017] Figure 1 A schematic diagram of the connection lines of a flow field separation device according to an embodiment of the utility model is shown.

[0018] Figure 2 The schematic diagram illustrates the current-carrying flow in a first state according to an embodiment of the present invention;

[0019] Figure 3 The schematic diagram illustrates the flow of current in a second state according to an embodiment of the present invention;

[0020] Figure 4 A schematic three-dimensional diagram of a flow field separation system according to an embodiment of the present invention is shown.

[0021] Figure 5 This is a separation diagram of polystyrene microspheres of different sizes according to Embodiment 1 of this utility model;

[0022] Figure 6 This is a separation diagram of a mixture of cadmium telluride quantum dots and gold nanoparticles of different sizes according to Embodiment 2 of this utility model.

[0023] Figure Labels

[0024] 1. Separate channels;

[0025] 11. First port;

[0026] 12. Second port;

[0027] 13. Third port;

[0028] 2. Sample introduction unit;

[0029] 3. Valve control unit;

[0030] 31. First electric valve;

[0031] 311. First Interface;

[0032] 312. Second interface;

[0033] 313. Third interface;

[0034] 32. Second electric valve;

[0035] 321. Fourth interface;

[0036] 322. Fifth Interface;

[0037] 323. The sixth interface;

[0038] 33. Third electric valve;

[0039] 331. Seventh Interface;

[0040] 332. Eighth Interface;

[0041] 333, Ninth Interface;

[0042] 334. Tenth Interface;

[0043] 4. Flow regulating valve;

[0044] 5. First three-way valve;

[0045] 6. Second three-way valve;

[0046] 7. Current-carrying device;

[0047] 8. Detection device;

[0048] 9. Waste liquid collection device. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0050] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. The terms “comprising,” “including,” etc., as used herein indicate the presence of features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0051] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0052] When using expressions such as "at least one of A, B, and C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C. Similarly, when using expressions such as "at least one of A, B, or C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C.

[0053] It should also be noted that the directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of this utility model. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted where they may cause confusion in understanding this utility model.

[0054] Figure 1 The schematic diagram illustrates the connection lines of a flow field separation device according to an embodiment of the utility model.

[0055] According to the provided hollow fiber flow field separation device, such as Figure 1 As shown, the system includes a separation channel 1, a sample introduction unit 2, and a valve control unit 3. The separation channel 1 has a first port 11, a second port 12 opposite to the first port 11, and a third port 13 near the second port 12. A hollow fiber membrane is embedded within the separation channel 1. The first port 11 and the second port 12 are respectively connected to an external flow-carrying device 7; the first port 11 and the third port 13 are also respectively connected to an external detection device 8. The sample introduction unit 2 is connected to both the second port 12 and the external flow-carrying device 7, and is suitable for introducing micro / nano particle samples into the separation channel 1. The valve control unit 3 is configured to automatically switch the flow path of the flow-carrying device, allowing the separation channel 1 to have the following two states:

[0056] First state: The current flows into the hollow fiber membrane through the first port 11 and the second port 12 respectively, causing the micro-nano particles to focus in the hollow fiber membrane, and causing the permeate separated by the hollow fiber membrane to flow to the detection device 8 through the third port 13.

[0057] Second state: The current flows into the separation channel 1 through the second port 12 to elute the micro-nano particles focused in the hollow fiber membrane, and flows to the detection device 8 through the first port 11.

[0058] The separation channel 1 includes a shell, and a hollow fiber membrane is disposed inside the shell. The hollow fiber membrane forms an internal channel. There is no fixed phase in the internal channel of the hollow fiber membrane. A large number of micropores are formed on the tube wall of the hollow fiber membrane. Ions, molecules and small nanoparticles can permeate out of the hollow fiber membrane through the micropores, while large micro-nano particles are trapped inside the hollow fiber membrane.

[0059] In the first state, the valve control unit 3 opens the channels between the external current-carrying device 7 and the first port 11, the channel between the current-carrying device 7 and the second port 12, and the channel between the third port 13 and the detection device 8. This controls the current to flow from the first port 11 and the second port 12 of the separation pipe into the separation pipe for counterflow. Microparticles of different sizes migrate towards the hollow fiber separation membrane under the influence of the flow field and their own Brownian motion, reaching equilibrium at different equilibrium positions near the inner wall of the membrane. At this time, ions, molecules, and small microparticles in the current-carrying material can permeate out of the hollow fiber membrane through the micropores, forming a permeate. The permeate flows from the third port 13 to the detection device 8 for detecting small microparticles. Large microparticles in the current-carrying material are confined to specific positions within the internal channels of the hollow fiber membrane, achieving focusing of the microparticles.

[0060] In the second state, the valve control unit 3 controls the channel between the first port 11 and the current-carrying device 7 to be closed, controls the channel between the second port 12 and the current-carrying device 7 to be opened, and controls the channel between the first port 11 and the detection device 8 to be opened, so that the current flows in from the second end of the separation pipeline, forming an axial flow from the second port 12 to the first port 11. The axial flow is used to elute micro-nano particles of different sizes according to their migration speed differences, and the particles flow from the first port 11 to the detection device 8, thereby realizing the analysis and characterization of micro-nano particles of different sizes.

[0061] In some embodiments, a preset duration of the first state can be set first, and the valve control unit 3 is used to make the separation channel 1 in the first state. When the preset duration of the first state is reached, the valve control unit 3 automatically switches the flow direction so that the separation channel 1 is in the second state.

[0062] According to an embodiment of this utility model, the flow path of the carrier is automatically switched by the valve control unit 3, thereby realizing the automated control of the focusing and elution stages of micro-nano particles in the separation channel 1, which improves the repeatability and stability of the separation effect of micro-nano particles.

[0063] According to an embodiment of the present invention, the valve control unit 3 includes multiple electric valves, which cooperate with each other to automatically switch the flow path of the first state and the second state respectively.

[0064] According to an embodiment of the present invention, the valve control unit 3 includes a first electric valve 31, which is adapted to be connected to the flow-carrying device 7 and the first port 11 respectively, so as to open the channel between the flow-carrying device 7 and the first port 11 in a first state.

[0065] Specifically, such as Figure 1 As shown, the first electric valve 31 is provided with a first interface 311 and a second interface 312. The first interface 311 is connected to the external flow-carrying device 7 in sequence through pipeline b1, the first three-way valve 5, and pipeline a1. The second interface 312 of the first electric valve 31 is connected to the second port 12 of the separation channel 1 through pipeline b2. The first flow-carrying channel is formed by pipelines a1, b1, and b2. In the first state, the first interface 311 and the second interface 312 are opened by the first electric valve 31, allowing the flow to flow into the first end of the separation pipe through the first flow-carrying channel.

[0066] According to an embodiment of the present invention, the first electric valve 31 is also adapted to be connected to the detection device 8 to close the channel between the current-carrying device 7 and the first port 11 in the second state, and to open the channel between the detection device 8 and the first port 11.

[0067] Specifically, the first electric valve 31 is also provided with a third interface 313. The third interface 313 is connected to the external detection device 8 in sequence through pipeline b3, the second three-way valve 6, and pipeline e1. Pipelines b2, b3, and e1 form a second flow-carrying channel. In the second state, the first electric valve 31 closes the channel between the first interface 311 and the second interface 312, and opens the second interface 312 and the third interface 313, so that the flow-carrying current flows from the second port 12 to the first port 11 and flows into the detection device 8 through the second flow-carrying channel for the analysis and characterization of micro and nano particles.

[0068] According to an embodiment of the present invention, the valve control unit 3 further includes a second electric valve 32, which is adapted to be connected to the third port 13 and the detection device 8 respectively, so as to open the channel between the third port 13 and the detection device 8 in a first state.

[0069] Specifically, the second control valve is equipped with a fourth port 321 and a fifth port 322. The third port 13 is connected to the fourth port 321 via pipeline d1, and the fifth port 322 is connected to the external detection device 8 via pipeline d2, the second three-way valve 6, and pipeline e1. Pipelines d1, d2, and e1 form a third flow-carrying channel. In the first state, the fourth port 321 and the fifth port 322 are opened by the second electric valve 32, allowing the permeate to flow from the third flow-carrying channel into the detection device 8. The detection device 8 can then be used to analyze and characterize ions, molecules, and small nanoparticles in the permeate.

[0070] According to an embodiment of the present invention, the second electric valve 32 is also adapted to be connected to an external waste liquid collection device 9 to close the channel between the third port 13 and the detection device 8 in the second state, and to open the channel between the third port 13 and the waste liquid collection device 9.

[0071] Specifically, the second electric valve 32 is also provided with a sixth port 323, which is connected to the external waste liquid collection device 9 via pipeline d3, and pipelines d1 and d3 form a fourth flow-carrying channel. In the second state, the second electric valve 32 is used to close the channels of the fourth port 321 and the fifth port 322, and open the channels of the fourth port 321 and the sixth port 323, allowing the permeate to flow into the waste liquid collection device 9 through the fourth flow-carrying channel.

[0072] According to an embodiment of the present invention, a flow regulating valve 4 is further provided between the second electric valve 32 and the waste liquid collection device 9. The flow regulating valve 4 is used to control the flow rate of the permeate in the second state.

[0073] Specifically, the flow regulating valve 4 can be installed on pipeline d3. Since the flow velocity in pipeline d3 is provided by the radial flow velocity of the permeate carried in the hollow fiber membrane of separation channel 1, by adjusting the flow velocity of d3, that is, adjusting the velocity of the permeate carried in the hollow fiber membrane, the radial and axial flow velocities of the permeate carried in the separation channel 1 during the elution stage can be adjusted.

[0074] According to an embodiment of the present invention, the valve control unit 3 further includes a third electric valve 33, which is adapted to be connected to the flow carrier 7 and the sample injection unit 2 respectively, so as to open the channel between the flow carrier 7 and the sample injection unit 2 in a first state and a second state.

[0075] In some embodiments, two channels with different flow rates can be provided in the third electric valve 33 to accommodate the flow rate requirements of micro-nano particles in the two different stages of focusing and elution within the hollow fiber membrane.

[0076] Specifically, the third electric valve 33 is equipped with a seventh port 331, an eighth port 332, a ninth port 333, and a tenth port 334. The seventh port 331 is connected to the flow carrier 7 via pipeline c1, the first three-way valve 5, and pipeline a1 in sequence. The ninth port 333 is connected to the tenth port 334 via an external pipeline c2. The eighth port 332 is connected to the second port 12 via pipeline c3, the sample injection unit 2, and pipeline c4 in sequence. Pipelines a1, c1, c2, c3, and c4 form the fifth flow carrier channel, and pipelines a1, c2, c3, and c4 form the sixth flow carrier channel.

[0077] In the first state, the seventh port 331 and the ninth port 333 are connected via the third electric valve 33, and the eighth port 332 and the tenth port 334 are connected, allowing the current to flow into the second end of the separation channel 1 along the fifth current-carrying channel. In the second state, only the seventh port 331 and the eighth port 332 are connected via the electric valve, allowing the current to flow into the second end of the separation channel 1 along the sixth current-carrying channel.

[0078] In some embodiments, the flow rate of the sixth flow-carrying channel can be adjusted by controlling the length and inner diameter of the pipeline c2.

[0079] According to an embodiment of the present invention, in a first state, the current carrying velocity of the first port 11 is configured to be greater than the current carrying velocity of the second port 12, so that the micro-nano particles are focused on the side near the third port 13.

[0080] Preferably, in the first state, the ratio of the current carrying velocity at the first port 11 to the current carrying velocity at the second port 12 is 9:1, thereby ensuring that the micro / nano particles are close to the vicinity of the third port 13, so that the permeate can flow out from the third port 13.

[0081] Specifically, the inner diameter of pipeline c2 can be set smaller than the inner diameter of other pipelines, thereby reducing the flow velocity to the second port 12 in the first state, so that the flow velocity of the first port 11 in the first state is configured to be greater than the flow velocity of the second port 12.

[0082] Preferably, pipeline c2 can be a pipeline with an inner diameter of 0.1 mm, and the inner diameter of the remaining pipelines ranges from 0.25 to 0.5 mm.

[0083] Figure 2 The schematic diagram illustrates the flow of the current carrier in a first state according to an embodiment of the present invention.

[0084] like Figure 2As shown, in the first state, the carrier fluid flows through pipeline a1 to the first three-way valve 5 and is split, flowing to the first electric valve 31 and the third electric valve 33 respectively. At this time, the first port 311 and the second port 312 of the first electric valve 31 are connected. The carrier fluid flows along pipelines b1 and b2 to the first end of the separation channel 1. The seventh port 331 and the ninth port 333 of the third electric valve 33 are connected, and the eighth port 332 and the tenth port 334 are connected. The carrier fluid flows along pipelines c1, c2, and c3 to the sample injection unit 2. After the sample is injected through the sample injection unit 2, it flows along pipeline c4 to the second port 12. Furthermore, the flow rate of the carrier fluid at the first port 11 is greater than that at the second port 12, causing the micro-nano particles to focus near the third port 13. At the same time, small molecules such as micro-nano particles, ions, and molecules permeate through the hollow fiber membrane, flowing out from the third port 13 as permeate, and flowing along pipeline c1 to the second electric valve 32. At this time, the second electric valve 32 connects the fourth port 321 and the fifth port 322, and the permeate flows along d2 and e1 to the detection device 8 for analysis and characterization.

[0085] Figure 3 The schematic diagram illustrates the flow of the current carrier in the second state according to an embodiment of the present invention.

[0086] Once the focusing phase has lasted for the predetermined duration, the first electric valve 31, the second electric valve 32, and the third electric valve 33 can automatically switch the flow path of the current carrier. For example... Figure 3 As shown, after switching from the first state to the second state, the carrier fluid flows only through pipelines a1 and c1 to the third electric valve 33. The third electric valve 33 only connects the seventh port 331 and the eighth port 332, allowing the carrier fluid to flow directly from the seventh port 331 to the eighth port 332 and along pipelines c3 and c4 to the second port 12 of the separation channel 1, and then out through the first port 11 to elute the focused micro / nano particles. The current then flows along pipeline b2 to the first electric valve 31. At this time, the first electric valve 31 connects the second port 312 and the third port 313, and the carrier fluid flows along pipelines b3 and e1 to the detection device 8. Simultaneously, the permeate from the hollow fiber membrane flows along pipeline d1 to the second electric valve 32. The second electric valve 32 then connects the fourth port 321 and the sixth port 323, allowing the permeate to flow along pipeline d3 into the waste liquid collection device 9 for recovery.

[0087] Figure 4 A schematic three-dimensional diagram of a flow field separation system according to an embodiment of the present invention is shown.

[0088] According to the hollow fiber flow field separation system provided by this utility model, such as Figure 4As shown, it includes: a hollow fiber flow field separation device, a current-carrying device 7, and a detection device 8. The current-carrying device 7 is connected to the hollow fiber flow field separation device and is suitable for supplying current to the hollow fiber flow field separation device. The detection device 8 is connected to the hollow fiber flow field separation device and is suitable for analyzing and characterizing the micro-nano particles flowing out of the hollow fiber flow field separation device in the first and second states.

[0089] Specifically, the current-carrying device 7 is connected to the first electric valve 31 and the third electric valve 33 via pipelines and the first three-way valve 5, respectively, to supply current to the separation channel 1 through the first electric valve 31 and the second electric valve 32. The detection device 8 is connected to the first electric valve 31 and the second electric valve 32 via pipelines and the second three-way valve 6, respectively, to detect the micro-nano particles, ions, and molecules flowing out in the first and second states, respectively.

[0090] In some embodiments, the detection device 8 includes an ultraviolet detector. In other embodiments, the detection device 8 includes an ultraviolet detector and other detectors connected in series.

[0091] According to an embodiment of this utility model, the flow-carrying device 7 includes a flow-carrying bottle and a plunger pump. The flow-carrying bottle is used to store the flow. The plunger pump is disposed between the flow-carrying bottle and the hollow fiber flow field separation device to deliver the flow to the hollow fiber flow field separation device.

[0092] In one illustrative embodiment, the hollow fiber flow field separation system of this invention can separate polystyrene microspheres of different sizes. Specifically, a hollow fiber membrane made of polyethersulfone (inner diameter 0.90 mm, outer diameter 1.50 mm, molecular weight cutoff 10 kDa) can be selected, and the carrier transport device is a plunger pump. The polystyrene microsphere mixture is injected into the carrier stream from the injection unit 2 via a manual microsyringe using a high-performance liquid chromatograph equipped with a quantitative loop (100 μL). A diode array detector (λ=254 nm) is used for the analysis and characterization of polystyrene microspheres of different sizes (1 μm, 5 μm, and 10 μm). The flow rate during the focusing stage is set to 0.6 mL / min, and the focusing time is set to 6 min; the total flow rate during the elution stage is set to 1.5 mL / min, and the radial flow rate is adjusted to 0.15 mL / min by the flow regulating valve 4, i.e., the axial flow rate of sample elution is 1.35 mL / min.

[0093] Figure 5 This is a separation diagram of polystyrene microspheres of different sizes according to Embodiment 1 of this utility model.

[0094] like Figure 5As shown, due to their large size, micron-sized particles are separated according to the steric hindrance mode, that is, the retention time of polystyrene microspheres decreases with increasing size. The sample peak signals of polystyrene microspheres of different sizes can be separated at the baseline. That is, the separation system of this invention can effectively separate micron-sized particles of different sizes.

[0095] In another illustrative embodiment, the hollow fiber flow field separation system of this invention can separate a mixture of cadmium telluride quantum dots and gold nanoparticles of different sizes. Specifically, a hollow fiber membrane made of polyethersulfone (inner diameter 0.90 mm, outer diameter 1.50 mm, molecular weight cutoff 10 kDa) is selected, and the carrier transport device is a plunger pump. The polystyrene microsphere mixture is injected into the carrier stream through a manual microsyringe from injection unit 2 using a high-performance liquid chromatography system equipped with a quantitative loop (100 μL). A diode array detector (λ=254 nm) is used to detect cadmium telluride quantum dots (5 nm) and gold nanoparticles of different sizes (15 nm and 40 nm). The flow rate during the focusing stage is set to 0.6 mL / min, and the focusing time is set to 6 min; the total flow rate during the elution stage is set to 1.5 mL / min, and the radial flow rate is adjusted to 0.3 mL / min by the flow regulating valve 4, i.e., the axial flow rate of sample elution is 1.2 mL / min.

[0096] Figure 6 This is a separation diagram of a mixture of cadmium telluride quantum dots and gold nanoparticles of different sizes according to Embodiment 2 of this utility model.

[0097] like Figure 6 As shown, cadmium telluride quantum dots smaller than the hollow fiber membrane permeate through separation channel 1 during the focusing stage, indicating that ions, molecules, and small nanoparticles permeating through during the focusing stage can be separated from larger nanoparticles and can be detected by detection device 8. Due to their small size, the separation of nanoparticles follows a normal pattern. The retention time of gold nanoparticles increases with size, and the sample peak signals of gold nanoparticles of different sizes can achieve baseline separation, indicating that the separation system can effectively separate nanoparticles of different sizes.

[0098] The embodiments of the present invention have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of the present invention is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of the present invention, and all such substitutions and modifications should fall within the scope of the present invention.

Claims

1. A hollow fiber flow field separation device, characterized in that, include: The separation channel has a first port, a second port opposite to the first port, and a third port near the second port. A hollow fiber membrane is embedded in the separation channel. The first port and the second port are respectively connected to an external current-carrying device. The first port and the third port are respectively connected to an external detection device. The sample introduction unit is connected to the second port and an external current-carrying device, respectively, and the sample introduction unit is suitable for introducing micro-nano particle samples into the separation channel; The valve control unit is configured to automatically switch the flow path of the flow carrier, so that the separation channel has the following two states: First state: The current flows into the hollow fiber membrane through the first port and the second port respectively, causing the micro-nano particles to focus in the hollow fiber membrane, and the permeate separated from the hollow fiber membrane flows to the detection device through the third port; Second state: The current flows into the separation channel through the second port to elute the micro-nano particles focused in the hollow fiber membrane, and then flows to the detection device through the first port.

2. The apparatus of claim 1, wherein, The valve control unit includes: A first electric valve is adapted to be connected to the current-carrying device and the first port respectively, so as to open the channel between the current-carrying device and the first port in a first state.

3. The apparatus of claim 2, wherein, The first electric valve is also adapted to be connected to the detection device to close the channel between the current-carrying device and the first port in the second state, and to open the channel between the detection device and the first port.

4. The apparatus of claim 1, wherein, The valve control unit also includes: A second electric valve is adapted to be connected to the third port and the detection device respectively, so as to open the channel between the third port and the detection device in a first state.

5. The apparatus of claim 4, wherein, The second electric valve is also adapted to connect to an external waste liquid collection device to close the channel between the third port and the detection device in the second state, and to open the channel between the third port and the waste liquid collection device.

6. The apparatus of claim 5, wherein, A flow regulating valve is also provided between the second electric valve and the waste liquid collection device. The flow regulating valve is used to control the flow rate of the permeate in the second state.

7. The apparatus of claim 1, wherein, The valve control unit also includes: A third electric valve is adapted to be connected to the flow carrier and the injection unit respectively, so as to open the channel between the flow carrier and the injection unit in a first state and a second state.

8. The apparatus of any one of claims 1-7, wherein, In the first state, the current carrying rate of the first port is configured to be greater than that of the second port, so that the micro-nano particles are focused on the side closer to the third port.

9. A hollow fiber flow field flow fractionation system characterized by, include: The hollow fiber flow field separation device according to any one of claims 1 to 8; A current-carrying device, connected to the hollow fiber flow field separation device, is suitable for supplying current to the hollow fiber flow field separation device; The detection device is connected to the hollow fiber flow field separation device and is suitable for analyzing and characterizing the micro-nano particles, ions and molecules flowing out of the hollow fiber flow field separation device in the first and second states.

10. The system of claim 9, wherein, The current-carrying device includes: A current-carrying bottle is used to store the current-carrying fluid; A plunger pump is provided between the carrier fluid bottle and the hollow fiber flow field flow fractionation device to deliver carrier fluid to the hollow fiber flow field flow fractionation device.

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