WO2023124437A1

WO2023124437A1 - Microfluidic chip, micro-reaction system, and quantum dot preparation method

Info

Publication number: WO2023124437A1
Application number: PCT/CN2022/126274
Authority: WO
Inventors: 王元
Original assignee: Tcl科技集团股份有限公司
Priority date: 2021-12-27
Filing date: 2022-10-19
Publication date: 2023-07-06
Also published as: CN116351482A

Abstract

A microfluidic chip, a micro-reaction system, and a quantum dot preparation method. A microfluidic chip (10) comprises an injection channel (11), a mixing channel (12), a reaction channel (13), and an outflow channel (14) communicated in sequence. A plurality of sub-reaction channels (131) are arranged in parallel so that the limited space of the chip is fully utilized, thereby increasing the amount of reaction liquid in a reaction state per unit time, increasing the yield of a generated product per unit time, and improving synthesis efficiency.

Description

Preparation method of microfluidic chip, microreaction system and quantum dot

This application claims the priority of the Chinese patent application with the application number 202111619508.6 and the application name "Microfluidic chip, microreaction system and preparation method of quantum dots" filed at the China Patent Office on December 27, 2021, which The entire contents are incorporated by reference in this application.

technical field

The present application relates to the field of microfluidic reactions, in particular to the preparation method of microfluidic chips, microreaction systems and quantum dots.

Background technique

Microfluidic reactions are also known as microchannel reactions, fluid microreactions, or microfluidic reactions. The microfluidic reaction replaces the traditional intermittent reaction with continuous flow, and reacts under the reaction conditions such as mixed reaction or heating in the microchannel through continuous fluid, and the target product is prepared by continuous synthesis, and the reaction can be precisely controlled on the microscopic scale, improving Reaction selectivity and operational safety. Due to its micron-sized channel structure, the microfluidic chip greatly improves the heat transfer and mass transfer performance of the reaction. When preparing materials such as nanocrystals or quantum dots, the time required for the precursor liquid to enter the heated state from the room temperature state in the chip is extremely short, indicating that in the microfluidic chip, the synthesis of quantum dots can be completed with an extremely short channel size.

technical problem

However, the current traditional chip channel structure is a helical or serpentine winding channel covering the chip plane. Such a single reaction channel not only wastes the chip space excessively, but also makes the synthesis efficiency of the reaction low.

technical solution

Therefore, the present application provides a method for preparing a microfluidic chip, a microreaction system and quantum dots.

An embodiment of the present application provides a microfluidic chip, including an injection channel, a mixing channel, a reaction channel, and an outflow channel connected in sequence; one end of the injection channel is a feed port, and the other end communicates with the mixing channel; One end of the mixing channel away from the injection channel is a split port, and the split port communicates with the reaction channel; the reaction channel includes a plurality of sub-reaction channels arranged in parallel, and one end of each sub-reaction channel is connected to the mixing channel. The diverging port at the other end is connected, and the other end is connected with the confluence port of the outflow channel; one end of the outflow channel is the confluence port, and the other end is the discharge port.

Optionally, in some embodiments of the present application, at least some of the sub-reaction channels have substantially the same volume.

Optionally, in some embodiments of the present application, at least some of the sub-reaction channels have substantially the same length.

Optionally, in some embodiments of the present application, among the plurality of sub-reaction channels, the central axis of each sub-reaction channel is located on the same plane; The reference line, in a direction away from the reference line, the length of the sub-reaction channel gradually increases, and the inner diameter of the sub-reaction channel gradually decreases.

Optionally, in some embodiments of the present application, the inner diameters of the multiple sub-reaction channels range from 450 μm to 650 μm.

Optionally, in some embodiments of the present application, the lengths of the multiple sub-reaction channels range from 80 mm to 167 mm.

Optionally, in some embodiments of the present application, each sub-reaction channel is formed by connecting multiple straight channels or is an arc channel.

Optionally, in some embodiments of the present application, the mixing channel is an S-shaped channel.

Optionally, in some embodiments of the present application, the inner diameter of the mixing channel is in a range of 3mm-5mm.

Optionally, in some embodiments of the present application, the microfluidic chip includes a plurality of injection channels, and the inner diameter of each injection channel ranges from 1 mm to 2 mm.

Optionally, in some embodiments of the present application, the inner diameter of the outflow channel is in the range of 3-5 mm.

Optionally, in some embodiments of the present application, the inner diameter of the outflow channel is the same as the inner diameter of the mixing channel.

Optionally, in some embodiments of the present application, the area where the reaction channel is located is a heating area.

Correspondingly, the embodiment of the present application also provides a micro-reaction system, including a sampling device, a microfluidic chip, and a product collection device; the microfluidic chip includes sequentially connected injection channels, mixing channels, reaction channels, and outflow channels One end of the injection channel is a feed port, connected to the sampling device; the other end of the injection channel communicates with the mixing channel; the end of the mixing channel away from the injection channel is a split port, the The split port is communicated with the reaction channel; the reaction channel includes a plurality of sub-reaction channels arranged in parallel, one end of each sub-reaction channel is communicated with the split port at the other end of the mixing channel, and the other end is connected with the outlet port of the outflow channel. The confluence port is connected; one end of the outflow channel is the confluence port, and the other end of the outflow channel is a discharge port, which communicates with the product collection device.

Correspondingly, the embodiment of the present application also provides a method for preparing quantum dots. The quantum dots are prepared by using a microfluidic chip, and the microfluidic chip includes an injection channel, a mixing channel, a reaction channel, and an outflow channel connected in sequence; Wherein, the reaction channel includes a plurality of sub-reaction channels arranged in parallel; the preparation method includes: the precursor solution flows in from the feed port of the injection channel, and flows through the mixing channel for mixing to obtain a mixed solution; the mixing The solution is divided into multiple sub-flows at the diversion port of the mixing channel, and flows into multiple sub-reaction channels arranged in parallel, and reacts in multiple sub-reaction channels to generate quantum dots; the multiple sub-flows flow through the confluence port for confluence , and flow through the outflow channel, and flow out of the microfluidic chip from the outlet of the outflow channel.

Optionally, in some embodiments of the present application, the times for the multiple branches to flow from the diversion port to the confluence port are the same.

Optionally, in some embodiments of the present application, the quantum dots are selected from at least one of single-structure quantum dots and core-shell structure quantum dots, and the material of the single-structure quantum dots is selected from group II-VI compounds , III-V group compound and at least one of I-III-VI group compound, and described II-VI group compound is selected from CdSe, CdS, CdTe, ZnSe, ZnS, CdTe, ZnTe, CdZnS, CdZnSe, CdZnTe, ZnSeS , ZnSeTe, ZnTeS, CdSeS, CdSeTe, CdTeS, CdZnSeS, CdZnSeTe and CdZnSTe at least one, the III-V group compound is selected from InP, InAs, GaP, GaAs, GaSb, AlN, AlP, InAsP, InNP, InNSb At least one of , GaAlNP and InAlNP, the I-III-VI group compound is selected from at least one of CuInS ₂ , CuInSe ₂ and AgInS ₂ ; the core of the quantum dot with the core-shell structure is selected from the above-mentioned single structure Any one of the quantum dots, the shell material of the quantum dots with core-shell structure is selected from at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS and ZnS.

Beneficial effect

The microfluidic chip of the present application supports the reaction solution to enter the microfluidic chip through the feed port of the injection channel, fully mix in the mixing channel, and flow into a plurality of parallel sub-reaction channels through the split port, and each sub-reaction channel The reaction liquids in the flow reaction are combined at the confluence port at the same time, and flow out of the microfluidic chip through the outflow channel, so as to use the microfluidic chip to complete the synthesis and preparation of the product. By setting multiple sub-reaction channels and making full use of the limited chip space, the amount of the reaction solution in the reaction state per unit time is increased, thereby increasing the yield of the generated product per unit time and improving the synthesis efficiency. At the same time, the micro-sized sub-reaction channel improves the heat transfer performance of the reaction solution and promotes the high-quality synthesis of products.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of a microfluidic chip provided in an embodiment of the present application;

Fig. 2 is a schematic structural view of a reaction channel provided in an embodiment of the present application;

Fig. 3 is the structural representation of a kind of micro-reaction system provided by the embodiment of the present application;

Fig. 4 is a schematic flow chart of a method for preparing quantum dots provided in an embodiment of the present application.

Embodiment of this application

The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts belong to the scope of protection of this application.

In addition, it should be understood that the specific implementations described here are only used to illustrate and explain the present application, and are not intended to limit the present application. In the present application, unless otherwise stated, the used orientation words such as "upper" and "lower" specifically refer to the direction of the drawings in the drawings. In addition, in the description of the present application, the term "including" means "including but not limited to". Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be construed as a rigid limitation on the scope of the present invention; therefore, the stated range should be considered The description has specifically disclosed all possible subranges as well as individual values within that range. For example, a description of a range from 1 to 6 should be considered to have specifically disclosed subranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and Single numbers within the stated ranges, eg 1, 2, 3, 4, 5 and 6, apply regardless of the range. Additionally, whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range.

In this application, "and/or" describes the association relationship of associated objects, indicating that there may be three types of relationships, for example, A and/or B, which may mean: A exists alone, A and B exist simultaneously, and B exists alone Condition. Among them, A and B can be singular or plural.

In this application, "at least one" means one or more, and "multiple" means two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, "at least one item (unit) of a, b, or c", or "at least one item (unit) of a, b, and c" can mean: a, b, c, a-b( That is, a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.

The microfluidic chip in this application refers to a chip that can perform microfluidic reactions, that is, channels for containing fluids, mixing units, reaction units, and other functional components are integrated on a micron-scale chip to manipulate micron-volume fluids in a micron The movement process in space, so as to realize the fluid reaction on the chip, and realize the continuous preparation of products, such as the continuous preparation of nanocrystals or quantum dots.

Please refer to FIG. 1 . FIG. 1 is a schematic structural diagram of a microfluidic chip provided in an embodiment of the present application. The microfluidic chip 10 includes an injection channel 11 , a mixing channel 12 , a reaction channel 13 and an outflow channel 14 . The injection channel 11 , the mixing channel 12 , the reaction channel 13 and the outflow channel 14 communicate in sequence.

Specifically, one end of the injection channel 11 is a feed port (not shown in the figure), and the other end communicates with the mixing channel 12 . The end of the mixing channel 12 away from the injection channel 11 is a split port 121 , and the split port 121 communicates with the reaction channel 13 . The reaction channel 13 includes a plurality of sub-reaction channels 131 arranged in parallel, one end of each sub-reaction channel 131 communicates with the split port 121 at the other end of the mixing channel 12 , and the other end of each sub-reaction channel 131 communicates with the confluence port 141 of the outflow channel 14 . One end of the outflow channel 14 is a confluence port 141, and the other end is a discharge port (not noted in the figure).

In this embodiment, the reaction solution enters the microfluidic chip 10 through the feed port of the injection channel 11, is fully mixed in the mixing channel 12, and flows into a plurality of parallel sub-reaction channels 131 through the split port 121, and each sub-reaction The reaction solution in the channel 131 is flowing and reacting at the same time and merged at the confluence port 141 , and flows out of the microfluidic chip 10 through the outflow channel 14 , so that the microfluidic chip 10 is used to complete the synthesis and preparation of the product. By arranging a plurality of sub-reaction channels 131, the limited chip space is fully utilized, and the amount of the reaction liquid in the reaction state per unit time is increased, thereby increasing the yield of the generated product per unit time and improving the synthesis efficiency. At the same time, the micro-sized sub-reaction channel 131 improves the heat transfer performance of the reaction solution and promotes high-quality synthesis and preparation of products.

One end of each sub-reaction channel 131 communicates with the diversion port 121 , and the other end of each sub-reaction channel 131 communicates with the confluence port 141 . The volume of the sub-reaction channel 131 is the channel volume from the diversion port 121 to the confluence port 141 , and the length of the sub-reaction channel 131 is the corresponding channel length from the diversion port 121 to the confluence port 141 .

Specifically, the volumes or volumes of at least some of the sub-reaction channels 131 are substantially the same, that is, the corresponding volumes of some of the sub-reaction channels 131 or all the sub-reaction channels 131 in the plurality of sub-reaction channels 131 are basically the same. The length of the sub-reaction channel 131 is inversely proportional to the square of the internal diameter, so that the reaction time of the reaction solution in each sub-reaction channel 131 is close or equal, and the reaction solution is approximately synchronously flowing in all microchannels, so that in each sub-reaction channel 131 When the fluid of the fluid enters the confluence port 141 of the outflow channel 14, the reaction state is consistent, avoiding that the reaction solution of the sub-reaction channel 131 has not completely reacted, and the reaction solution of the sub-reaction channel 131 has completely reacted, thereby causing the outflow channel 14 to flow out. The reaction stages of the mixed reaction solution are different, thus affecting the state and quality of the product.

Further, at least part of the sub-reaction channels 131 have substantially the same volume or volume, and at least part of the sub-reaction channels 131 have the same length. Since the volume of the sub-reaction channels 131 is related to the length and inner diameter, the inner diameters of the plurality of sub-reaction channels 131 are also the same. At this time, multiple sub-reaction channels 131 may not be arranged on the same plane, that is, the microfluidic chip 10 has a three-dimensional structure, thereby improving the synthesis efficiency of the product prepared by using the microfluidic chip 10, while ensuring that the outflow channel 14 flows out and collects The reaction stages of the mixed reaction solution are the same, thereby improving the synthesis consistency and product quality of the product. For example, when synthesizing quantum dots, improve the concentration of quantum dot size distribution.

In another embodiment, the microfluidic chip 10 is a planar structure, and among the plurality of sub-reaction channels 131 disposed on it, the central axis of each sub-reaction channel 131 is located on the same plane. At this time, all sub-reaction channels 131 are on the same plane. Taking the connection line between the diversion port 121 and the confluence port 141 as the reference line aa', in the directions X and X' away from the reference line aa', the length of the sub-reaction channel 131 gradually increases, and the length of the sub-reaction channel 131 The inner diameter gradually decreases.

Each sub-reaction channel 131 is on the microfluidic reaction chip 10 and is on the same plane, so the lengths may be different when they are connected in parallel. The channel is the straight line connection between the diverging port 121 and the converging port 141 , that is, the reaction channel coincident with the reference line aa'. And along the direction away from the reference line aa', that is, in the direction perpendicular to the reference line aa', the length of the sub-reaction channel 131 gradually increases, that is, the closer the sub-reaction channel 131 to the reference line aa' The shorter the sub-reaction channel 131 is, the farther away from the reference line aa' is the longer. Certainly, the sub-reaction channel 131 coincident with the reference line a-a' may be provided, or the sub-reaction channel 131 coincident with the reference line a-a' may not be provided, which is not limited here. In the direction away from the reference line a-a', the length of the sub-reaction channel 131 gradually increases, and the inner diameter of the sub-reaction channel 131 gradually decreases, and the decrease in the inner diameter will lead to an increase in the flow rate, so that the longer length The flow velocity of the sub-reaction channel 131 is also relatively large, so that the reaction time of the reaction solution in each sub-reaction channel 131 is approximate, and the reaction solution flows and reacts approximately synchronously in all microchannels, so that the fluid in each sub-reaction channel 131 enters When the confluence port 141 of the outflow channel 14, the reaction state is consistent, avoiding that the reaction solution of the sub-sub-reaction channel 131 has not completely reacted, while the reaction solution of the sub-sub-reaction channel 131 has completely reacted, resulting in the mixed reaction solution flowing out of the outflow channel 14. The reaction stage is different, which affects the state of the product and product quality.

Further, the volumes of the sub-reaction channels 131 may be the same. Referring to FIG. 2, FIG. 2 is a schematic structural diagram of a reaction channel provided in an embodiment of the present application. The reaction channel 13 includes a first sub-reaction channel ACDB and a second sub-reaction channel AEFB. The length of the first sub-reaction channel ACDB is denoted as L ₁ , and the inner diameter is r ₁ . The length of the second sub-reaction channel AEFB is denoted as L ₂ , and the inner diameter is r ₂ . The volumes of the first sub-reaction channel ACDB and the second sub-reaction channel AEFB are the same, and according to the volume formula, two sub-reaction channels 131 can be obtained to satisfy the formula (I):

r ₁ ² L ₁ ＝r ₂ ² L ₂ formula (I)

That is, the length of the sub-reaction channel 131 is inversely proportional to the square of the inner diameter.

Further, each sub-reaction channel 131 may be formed by connecting multiple segments of straight channels. Referring to Fig. 2, taking the three-section straight channel as an example, the first sub-reaction channel ACDB includes section AC, section CD and section DB, the lengths of which are L ₁₁ , L ₁₂ and L ₁₃ respectively. The second sub-reaction channel AEFB includes an AE segment, an EF segment and a FB segment, and the lengths are L ₂₁ , L ₂₂ and L ₂₃ respectively. Then formula (I) is correspondingly transformed into r ₁ ² (L ₁₁ +L ₁₂ +L ₁₃ )=r ₂ ² (L ₂₁ +L ₂₂ +L ₂₃ ). Further, the volume of each section in each sub-reaction channel 131 can be made the same, that is, r ₁ ² L ₁₁ =r ₂ ² L ₂₁ , r ₁ ² L ₁₂ =r ₂ ² L ₂₂ , r ₁ ² L ₁₃ =r ₂ ² L ₂₃ . And each sub-reaction channel 131 itself may be an axisymmetric structure. For example, the first sub-reaction channel ACDB has an axisymmetric structure with the midline of the CD segment as the axis. At this time, the AC segment and the DB segment are axisymmetrically distributed and have the same length, that is, L ₁₁ =L ₁₃ is satisfied.

Of course, the sub-reaction channel 131 can also be an arc-shaped channel, and the arc of the sub-reaction channel 131 is different according to the distance from the reference line a-a'. For example, the sub-reaction channel 131 closer to the reference line a-a' has a smaller arc, while the sub-reaction channel 131 farther away from the reference line a-a' has a larger arc.

In one embodiment, the inner diameters of the sub-reaction channels 131 range from 450 μm to 650 μm. When channels with inner diameters in this range are used for fluid reactions such as heating, it can avoid losing its advantages in heat and mass transfer as a microfluidic reaction when the inner diameter is too large, and it can also avoid large flow rates and small reaction volumes caused by too small inner diameters It is beneficial to the synthesis and preparation of products and ensures higher yield and synthesis efficiency.

The length of the sub-reaction channels 131 can be set correspondingly based on different fluid reactions. For example, nanocrystals or quantum dots are synthesized through the reaction channel 13 in the heating area, and the length range of each sub-reaction channel 131 in the reaction channel 13 is set according to the reaction requirements for synthesizing nanocrystals or quantum dots. When the length of the sub-reaction channel 131 is too short, the reaction liquid flows through for too short a time, and the reaction will be insufficient; if the purpose of increasing the reaction time is achieved by reducing the flow rate, the synthesis efficiency of the product will be reduced. After the reaction solution has been completely reacted in the channel, the too long length will not have a positive effect on the synthesis efficiency of the reaction, and will cause waste of the pipeline.

Specifically, the mixing channel 12 may be a channel known in the art for mixing reactants. In a specific embodiment, the mixing channel 12 is an S-shaped channel or a serpentine channel, and may be a multi-segment bent S-shaped channel, so as to fully mix the reaction solution and reduce the occupied area of the mixing channel 12 . Further, the inner diameter of the serpentine mixing channel 12 may be 3-5mm. The S-shaped section channel is only used as the reaction and also flows to the mixing before the heating area. The inner diameter of the mixing channel 12 can satisfy the liquid flow of a relatively large flow rate, so as to provide sufficient reaction liquid for multiple sub-reaction channels 131 in the reaction area, so The inner diameter cannot be too small. However, if the inner diameter is too large, the liquid flow rate in this section of the channel will slow down due to the limited flow rate of the injection channel, and there may be an interference cavity in the mixing channel 12 to retain gas, which will affect the synthesis effect.

In one embodiment, the microfluidic chip 10 may include a plurality of injection channels 11 for injecting different fluid reactants, so as to perform sufficient and uniform mixing in the subsequent mixing channel 12 and rapid and sufficient reaction in the reaction channel 13 . Wherein, the inner diameter range of each injection channel 11 is 1-2 mm. If the inner diameter of the injection channel 11 is too large, accompanied by an excessive liquid flow rate, it will generate a relatively large pressure and even block the flow of the smaller reaction channel 13 connected thereafter; if the inner diameter is too small, the flow rate will be seriously insufficient , it is difficult to achieve the purpose of efficiently synthesizing products.

In one embodiment, the inner diameter of the outflow channel 14 is in the range of 3-5mm, which can adapt to the flow rate of the mixing channel 12 and the reaction channel 13 connected to the front end, without causing fluid congestion, and the inner diameter is too small to cause the entire microfluidic chip to 10 Channel pressure increases. Further, the inner diameter of the outflow channel 14 can be kept consistent with the inner diameter of the mixing channel 12 , so that the outflow channel 14 and the mixing channel 12 can meet the same flow rate of liquid.

However, the volumes of multiple sub-reaction channels 131 are controlled to be substantially the same, so that the reaction time of the reaction solution in each sub-reaction channel is approximate, and the reaction solution flows and reacts approximately synchronously in all micro-channels, so that the fluid in each sub-reaction channel 131 enters and flows out. When the confluence port 141 of passage 14, reaction state is consistent, avoids that the reaction liquid of partial sub-reaction passage 131 is not fully reacted, and the reaction liquid of partial sub-reaction passage 131 has reacted completely, thereby causes the mixed reaction liquid that flows out passage 14 to flow out The reaction stages are different.

In this application, the area where the reaction channel 13 is located in the microfluidic chip is a heatable area. This area can be in a heated state, so that the inflowing and uniformly mixed reaction solution is rapidly heated to the reaction temperature when it enters the reaction channel 13 , and the reaction is quickly completed in the shorter reaction channel 13 . It can be understood that a heating device can be arranged outside the microfluidic chip to heat the region where the reaction channel 13 is located, or a heating layer can be arranged in the microfluidic chip, and the heating layer is arranged in the region corresponding to the reaction channel 13 .

The present application also provides a micro-reaction system, refer to FIG. 3 , which is a schematic structural diagram of a micro-reaction system provided in an embodiment of the present application. The micro reaction system 100 includes a sampling device 20 , a microfluidic chip 10 and a product collection device 30 . The sampling device 20, the microfluidic chip 10 and the product collection device 30 are connected in sequence, so as to realize the sampling of the reaction liquid, the mixed reaction and the collection of the product through the micro reaction system.

Wherein, the microfluidic chip 10 includes an injection channel 11 , a mixing channel 12 , a reaction channel 13 and an outflow channel 14 connected in sequence. One end of the injection channel 11 is a feed port, which is connected with a sampling device 20 . The other end of the injection channel 11 communicates with the mixing channel 12 . The end of the mixing channel 12 away from the injection channel 11 is a split port 121 , and the split port 121 communicates with the reaction channel 13 . The reaction channel 13 includes a plurality of sub-reaction channels 131 arranged in parallel, one end of each sub-reaction channel 131 communicates with the split port 121 of the mixing channel 12 , and the other end communicates with the confluence port 141 of the outflow channel 14 . One end of the outflow channel 14 is a confluence port 141 , and the other end of the outflow channel 14 is a discharge port, which communicates with the product collecting device 30 . Wherein, for the microfluidic chip 10, reference may be made to relevant descriptions above, and details are not repeated here.

In the micro reaction system 100 in this embodiment, the reaction raw materials in the sampling device 20 or various materials enter the microfluidic chip 10 through the feed port of the injection channel 11, fully mix in the mixing channel 12, and flow into the microfluidic chip 12 through the split port 121. In a plurality of sub-reaction channels 131 connected in parallel, the reaction liquid in each sub-reaction channel 131 is flowing and reacting at the same time and converging at the confluence port 141, and flows out of the microfluidic chip 10 through the outflow channel 14, that is, the fluid flows through the outlet Enter the product collection device 30 to realize the collection of products. By arranging a plurality of sub-reaction channels 131, the limited chip space is fully utilized, and the amount of the reaction liquid in the reaction state per unit time is increased, thereby increasing the yield of the generated product per unit time and improving the synthesis efficiency. At the same time, the micro-sized sub-reaction channel 131 improves the heat transfer performance of the reaction solution and promotes high-quality synthesis and preparation of products.

The present application also provides a method for preparing quantum dots, using a microfluidic chip to prepare quantum dots. The microfluidic chip includes sequentially connected injection channels, mixing channels, reaction channels, and outflow channels; multiple sub-reaction channels. For the injection channel, the mixing channel, the reaction channel and the outflow channel, reference may be made to the relevant descriptions in the above embodiments, and details are not repeated here.

Quantum dots in the present application can be selected from at least one of single-structure quantum dots and core-shell structure quantum dots, and the materials of single-structure quantum dots are selected from II-VI group compounds, III-V group compounds and I-III- At least one of the group VI compounds, the group II-VI compound is selected from CdSe, CdS, CdTe, ZnSe, ZnS, CdTe, ZnTe, CdZnS, CdZnSe, CdZnTe, ZnSeS, ZnSeTe, ZnTeS, CdSeS, CdSeTe, CdTeS, CdZnSeS, At least one of CdZnSeTe and CdZnSTe, the III-V group compound is selected from at least one of InP, InAs, GaP, GaAs, GaSb, AlN, AlP, InAsP, InNP, InNSb, GaAlNP and InAlNP, I-III-VI The family compound is selected from at least one of CuInS ₂ , CuInSe ₂ and AgInS ₂ ; the core of the quantum dot with the core-shell structure is selected from any of the above-mentioned single-structure quantum dots, and the shell material of the quantum dot with the core-shell structure is selected from At least one selected from CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS and ZnS.

Referring to Fig. 4, Fig. 4 is a schematic flow diagram of a quantum dot preparation method provided in the embodiment of the present application, which specifically includes the following steps:

Step S11: the precursor solution flows in from the feed port of the injection channel, and flows through the mixing channel for mixing to obtain a mixed solution.

In this step, the precursor solution may be pre-mixed, injected through an injection channel, and further mixed in the mixing channel to obtain a mixed solution. Alternatively, the precursor solutions may be of various types, such as an anion precursor solution and a cation precursor solution, which are respectively injected through different injection channels and mixed in the mixing channel to obtain a mixed solution.

Step S12: the mixed solution is divided into multiple branch streams at the split port of the mixing channel, and flows into multiple sub-reaction channels arranged in parallel, and reacts in the multiple sub-reaction channels to generate quantum dots.

In the previous step, the fully mixed mixed solution is obtained by flowing through the mixed solution, which is divided into multiple branch streams at the branch flow port, and flows into multiple sub-reaction channels for reactions to generate quantum dots. Further, the area corresponding to the reaction channel including multiple sub-reaction channels is a heating area. By heating the reaction channel to reach the temperature required for the reaction, after each branch flow enters each sub-reaction channel, due to the small size of the channel, it has better heat transfer performance, so the mixed liquid in each branch flow can quickly heat up to reach the reaction temperature. temperature, so as to quickly complete the synthesis and preparation of quantum dots.

Step S13: the multiple branches flow through the confluence port for confluence, flow through the outflow channel, and flow out of the microfluidic chip from the outlet of the outflow channel.

In this step, after the solution containing the quantum dots flows out of the microfluidic chip, the quantum dots can be collected.

In this embodiment, the mixed solution of the precursor can flow synchronously in multiple sub-reaction channels of the microfluidic chip for reaction, which increases the amount of reaction liquid for synchronous reaction and increases the amount of reaction liquid in the reaction state per unit time. amount, thereby increasing the yield of quantum dots per unit time and improving the synthesis efficiency of quantum dots. At the same time, through the reaction of multiple branch streams, the advantages of high heat and mass transfer of multiple micro-sized sub-reaction channels are used to improve the heat transfer performance of the reaction liquid and promote the high-quality synthesis and preparation of products.

Further, in one embodiment, the times for the multiple branch streams to flow from the diverging port to the converging port are the same. Specifically, the multiple sub-reaction channels in the multiple sub-reaction channels can be controlled to flow from the split port to the confluence port at the same time through the settings of the multiple sub-reaction channels of the above-mentioned microfluidic chip in the present application. For the relevant description of the multiple sub-reaction channels and the microfluidic chip including them, reference may be made to the above, and details will not be repeated here. Of course, it is also possible to control the flow time from the diverging port to the converging port to be the same by setting a valve for at least one of the multiple branch streams.

That is to say, after the mixed solution is divided into multiple branch streams at the split port, the residence time of each branch stream in its corresponding sub-reaction channel is the same. Therefore, while improving the synthesis efficiency of quantum dots, it can ensure that the reaction stages of the mixed solutions flowing to the confluence port are the same or the state of the quantum dots is the same, thereby improving the synthesis consistency and product quality of quantum dots, and improving the quality of the microfluidics. Control the concentration of the quantum dot size distribution prepared by the chip.

The preparation method of the microfluidic chip, the microreaction system and the quantum dots provided by the embodiments of the present application have been introduced in detail above. In this paper, specific examples have been used to illustrate the principles and implementation methods of the present application. The description of the above embodiments It is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation and application scope. In summary, this The content of the description should not be understood as limiting the application.

Claims

A microfluidic chip, which includes sequentially connected injection channels, mixing channels, reaction channels and outflow channels;

One end of the injection channel is a feed port, and the other end communicates with the mixing channel;

The end of the mixing channel away from the injection channel is a split port, and the split port communicates with the reaction channel;

The reaction channel includes a plurality of sub-reaction channels arranged in parallel, one end of each sub-reaction channel communicates with the split port at the other end of the mixing channel, and the other end communicates with the confluence port of the outflow channel;

One end of the outflow channel is the confluence port, and the other end is the discharge port.
The microfluidic chip according to claim 1, wherein at least some of the sub-reaction channels have substantially the same volume.
The microfluidic chip according to claim 2, wherein at least some of the sub-reaction channels have substantially the same length.
The microfluidic chip according to any one of claims 1-3, wherein, among the plurality of sub-reaction channels, the central axes of each of the sub-reaction channels are located on the same plane;

Taking the connection line between the diversion port and the confluence port as a reference line, the length of the sub-reaction channels gradually increases and the inner diameter of the sub-reaction channels gradually decreases in a direction away from the reference line.
The microfluidic chip according to claim 4, wherein the inner diameters of the plurality of sub-reaction channels range from 450 μm to 650 μm.
The microfluidic chip according to claim 4, wherein the lengths of the multiple sub-reaction channels range from 80 mm to 167 mm.
The microfluidic chip according to claim 1, wherein each of the sub-reaction channels is formed by connecting a plurality of straight channels or is an arc channel.
The microfluidic chip according to claim 1, wherein the mixing channel is an S-shaped channel.
The microfluidic chip according to claim 8, wherein the inner diameter of the mixing channel is in the range of 3mm-5mm.
The microfluidic chip according to any one of claims 1-9, wherein the microfluidic chip comprises a plurality of injection channels, each of which has an inner diameter ranging from 1 mm to 2 mm.
The microfluidic chip according to any one of claims 1-10, wherein the inner diameter of the outflow channel is in the range of 3-5mm.
The microfluidic chip according to claim 11, wherein the inner diameter of the outflow channel is the same as that of the mixing channel.
The microfluidic chip according to any one of claims 1-12, wherein the area where the reaction channel is located is a heating area.
A micro-reaction system, including a sampling device, a microfluidic chip and a product collection device;

The microfluidic chip includes an injection channel, a mixing channel, a reaction channel and an outflow channel connected in sequence;

One end of the injection channel is a feed port connected to the sampling device, and the other end of the injection channel communicates with the mixing channel;

The end of the mixing channel away from the injection channel is a split port, and the split port communicates with the reaction channel;

The reaction channel includes a plurality of sub-reaction channels arranged in parallel, one end of each sub-reaction channel communicates with the split port at the other end of the mixing channel, and the other end communicates with the confluence port of the outflow channel;

One end of the outflow channel is the confluence port, and the other end of the outflow channel is a discharge port, which communicates with the product collecting device.
The micro-reaction system according to claim 14, wherein at least some of the sub-reaction channels have substantially the same volume.
The micro-reaction system according to claim 15, wherein at least some of the sub-reaction channels have substantially the same length.
The micro-reaction system according to any one of claims 14-16, wherein, among the plurality of sub-reaction channels, the central axis of each sub-reaction channel is located on the same plane;

Taking the connection line between the diversion port and the confluence port as a reference line, the length of the sub-reaction channels gradually increases and the inner diameter of the sub-reaction channels gradually decreases in a direction away from the reference line.
A method for preparing quantum dots, wherein the quantum dots are prepared using a microfluidic chip, and the microfluidic chip includes sequentially connected injection channels, mixing channels, reaction channels and outflow channels; wherein the reaction channels include Multiple sub-reaction channels arranged in parallel;

Described preparation method comprises:

The precursor solution flows in from the feed port of the injection channel, and flows through the mixing channel for mixing to obtain a mixed solution;

The mixed solution is divided into multiple branches at the split port of the mixing channel, and flows into a plurality of sub-reaction channels arranged in parallel, and reacts in a plurality of sub-reaction channels to generate quantum dots;

The multiple branches flow through the confluence port for confluence, flow through the outflow channel, and flow out of the microfluidic chip through the outlet of the outflow channel.
The preparation method according to claim 18, wherein the times of the multiple branch streams flowing from the diverging port to the converging port are the same.
The preparation method according to claim 18, wherein the quantum dots are selected from at least one of single-structure quantum dots and core-shell structure quantum dots, and the material of the single-structure quantum dots is selected from group II-VI compounds, At least one of the III-V group compound and the I-III-VI group compound, the II-VI group compound is selected from CdSe, CdS, CdTe, ZnSe, ZnS, CdTe, ZnTe, CdZnS, CdZnSe, CdZnTe, ZnSeS, At least one of ZnSeTe, ZnTeS, CdSeS, CdSeTe, CdTeS, CdZnSeS, CdZnSeTe and CdZnSTe, the III-V group compound is selected from InP, InAs, GaP, GaAs, GaSb, AlN, AlP, InAsP, InNP, InNSb, At least one of GaAlNP and InAlNP, the I-III-VI group compound is selected from at least one of CuInS 2 , CuInSe 2 and AgInS 2 ; the core of the quantum dot with the core-shell structure is selected from the above-mentioned single-structure quantum Any one of the dots, the shell material of the core-shell quantum dot is selected from at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS and ZnS.