Microreaction chip, control method and microreaction system

Abstract

The application provides a micro-reaction chip, comprising a chip substrate and a flow channel arranged on the chip substrate; the chip substrate is provided with a heating area; the flow channel comprises a first channel and a second channel, and the first channel and the second channel form a mixing cavity at a communication position; and the first channel and / or the second channel is at least partially located in the heating area between the inlet and the mixing cavity. When the micro-reaction chip is used for micro-reaction, the temperature in the mixing cavity can be flexibly controlled when different solutions flowing through different channels are mixed in the mixing cavity. When the micro-reaction chip is used for quantum dot synthesis, since the anion precursor solution and the cation precursor solution can flow into the mixing cavity at different temperatures, the temperature of the solution in the mixing cavity can be freely regulated, so that the nucleation and growth of quantum dots are separated, and high-quality fluorescent quantum dot materials with narrow size distribution can be synthesized.

Description

Technical Field

[0001] This application relates to the field of chip technology, specifically to a microreaction chip (microfluidic chip), a microcontroller method, and a microreaction system. Background Technology

[0002] Quantum dots, as a popular modern nanomaterial for optoelectronic applications, are widely used in fields such as light emission, displays, batteries, and biosensing due to their unique structure and properties. However, the quality and large-scale production of quantum dot materials synthesized in traditional three-necked flasks cannot meet the needs of various fields. Therefore, microreactor devices for continuous synthesis of quantum dots, represented by microfluidic chips, have become the preferred choice for researchers.

[0003] However, current microreactor chips primarily employ two injection methods for quantum dot synthesis. One method involves first filling a single syringe with all premixed anion and cation precursor solutions, then using the syringe to push the mixture into the heating zone at a target flow rate for reaction. The other method involves filling separate syringes with different ion precursor solutions, setting a target flow rate based on the molar ratio of the different ions, then merging all ion solutions at a confluence point before pushing the mixture into the heating zone to initiate the reaction. In this synthesis method, because the different ion precursor solutions are mixed and heated in the same space, quantum dot nucleation and growth occur simultaneously, making it difficult to synthesize high-quality fluorescent quantum dot materials with narrow size distributions. Summary of the Invention

[0004] This application provides a microreaction chip, a control method, and a microreaction system to solve the technical problem that unreasonable flow channel structure design of existing microreaction chips makes it difficult to synthesize high-quality fluorescent quantum dot materials with narrow size distribution.

[0005] On the one hand, this application provides a microreaction chip, including a chip substrate and flow channels disposed on the chip substrate;

[0006] The chip substrate is provided with a heating area;

[0007] The flow channel includes a first channel and a second channel, and the first channel and the second channel form a mixing cavity at the connection point;

[0008] The portion of the first channel and / or the second channel between its inlet and the mixing chamber is at least partially located within the heating area.

[0009] In some embodiments of this application, the chip substrate is further provided with a non-heated area, the first channel is disposed in the non-heated area, the second channel is at least partially located in the heated area, the heated area is disposed adjacent to the non-heated area, and the mixing cavity is disposed in the heated area and adjacent to the boundary between the heated area and the non-heated area.

[0010] In some embodiments of this application, the flow channel further includes a third channel that connects the outlet of the flow channel and the mixing chamber, and the third channel includes a meandering pipeline section disposed in the heating area.

[0011] In some embodiments of this application, the inner wall of the flow channel is provided with a protruding structure.

[0012] In some embodiments of this application, the non-heated area is located on the upper part of the chip substrate, the heated area is located at the end of the chip substrate away from the non-heated area, and the entrances of the first channel and the second channel are both located on one side of the non-heated area.

[0013] In some embodiments of this application, the microreaction chip is used for the synthesis of quantum dot materials.

[0014] The temperature of the first solution flowing into the mixing chamber through the inlet of the first channel is T1;

[0015] The temperature of the second solution flowing into the mixing chamber through the inlet of the second channel is T2;

[0016] Wherein, the first solution and the second solution are mixed in the mixing chamber to form a reaction solution; T1 or T2 is higher than or equal to the nucleation temperature of the reaction solution, and the temperature of the reaction solution in the mixing chamber is lower than the nucleation temperature.

[0017] This application also provides a microreaction control method, the control method comprising:

[0018] A microreactor chip is provided, the microreactor chip including a chip substrate and flow channels disposed on the chip substrate; the chip substrate has a heating region; the flow channels include a first channel and a second channel, the first channel and the second channel forming a mixing cavity at a connection point; the portion of the first channel and / or the second channel between its respective inlet and the mixing cavity is at least partially located within the heating region.

[0019] In some embodiments of this application, the first solution includes an anionic precursor solution, the second solution includes a cationic precursor solution, and the first solution and the second solution are mixed in the mixing chamber to form a reaction solution; wherein, T1 or T2 is higher than the nucleation temperature of the reaction solution, and the temperature of the reaction solution in the mixing chamber is lower than the nucleation temperature.

[0020] In some embodiments of this application, the flow channel further includes a third channel communicating with the outlet of the flow channel and the mixing chamber. The third channel includes a meandering pipeline portion disposed in the heating region. The control method further includes...

[0021] The reaction liquid is driven to flow along the meandering pipeline at a preset temperature.

[0022] This application also provides a method for controlling the synthesis of quantum dot materials, including,

[0023] A microreactor chip is provided, the microreactor chip including a chip substrate and flow channels disposed on the chip substrate; the chip substrate is provided with a heating region; the flow channels include a first channel and a second channel, the first channel and the second channel forming a mixing cavity at the connection point;

[0024] The anion precursor solution is driven to flow into the mixing chamber from the inlet of the first channel, and the temperature at which it flows into the mixing chamber is T1;

[0025] The cationic precursor solution is driven to flow into the mixing chamber from the inlet of the second channel, and the temperature at which it flows into the mixing chamber is T2;

[0026] The anion precursor solution and the cation precursor solution are mixed in the mixing chamber to form a reaction solution; T1 or T2 is higher than the nucleation temperature of the reaction solution, and the temperature of the reaction solution in the mixing chamber is lower than the nucleation temperature.

[0027] This application also provides a method for fabricating a microreaction chip, the method comprising,

[0028] A chip substrate is provided, wherein a heating area is provided on the chip substrate;

[0029] Etch the chip substrate to form flow channels on the chip substrate;

[0030] The flow channel includes a first channel and a second channel, which form a mixing chamber at their connection point, and the first channel and / or the second channel are at least partially located within the heating area; the temperature of the solution flowing into the mixing chamber through the inlet of the first channel is T1, and the temperature of the solution flowing into the mixing chamber through the inlet of the second channel is T2, and T1 and T2 are different temperature values.

[0031] In another aspect, this application provides a microreaction system comprising any of the microreaction chips described above.

[0032] This application involves providing a first channel, a second channel, and a heating region on a chip substrate. Since the portion of the first channel and / or the second channel between its inlet and the mixing chamber 160 is at least partially located within the heating region, the temperature at which a solution (e.g., a cation precursor solution) flows into the mixing chamber through the inlet of the first channel is T1, and the temperature at which a solution (e.g., an anion precursor solution) flows into the mixing chamber through the inlet of the second channel is T2, with T1 and T2 being different temperature values. Compared to existing microreactor chips where the temperature can be flexibly controlled when different solutions flowing into the mixing chamber via different channels are mixed during microreactor applications, this application's microreactor chip, when used for quantum dot synthesis, allows for flexible temperature control of the solution within the mixing chamber by controlling temperatures T1 and T2, as the anion and cation precursor solutions can flow into the mixing chamber at different temperatures. This enables rapid nucleation of the anion and cation precursor solutions within the mixing chamber, separating quantum dot nucleation and growth, which is beneficial for synthesizing high-quality fluorescent quantum dot materials with narrow size distributions. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the microreaction chip provided in the embodiments of this application from one view.

[0035] Figure 2 yes Figure 1 A magnified view of a section at point A in the middle;

[0036] Figure 3 This is a process flow diagram of the microreaction control method provided in the embodiments of this application.

[0037] Figure description: Microreactor chip 100, chip substrate 110, heating area 120, first channel 130, first channel inlet 1310, second channel 140, second channel inlet 1410, third channel 150, outlet 1510, detour pipeline section 1520, mixing chamber 160, non-heating area 170. Detailed Implementation

[0038] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0040] In this application, the term "exemplary" is used to mean "serving as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0041] Please see Figure 1 and Figure 2 , Figure 1This is a schematic diagram of the structure of a microreaction chip from a certain perspective, provided in an embodiment of this application. Figure 2 This is a magnified view of a portion at point A in section 1. The microreactor chip 100 includes a chip substrate 110.

[0042] Specifically, the chip substrate 110 in this embodiment can be a glass substrate or a substrate of other materials, such as a ceramic substrate. The type of chip substrate can be selected according to the specific usage environment and is not limited here.

[0043] A heating region 120 is provided on the chip substrate 110. The heating region 120 can be a portion of the chip substrate or the entire chip substrate. The portion of the chip substrate 110 located within the heating region 120 can be heated. One feasible approach is to place the chip substrate 110 within a chip tray capable of heating the chip substrate, for example, placing the heating region of the chip substrate within the chip tray, thereby controlling the temperature of the heating region on the chip substrate.

[0044] This can be achieved by heating a portion of the chip substrate 110. For example... Figure 1 As shown in this embodiment, the end of the chip substrate 110 furthest from the liquid inlet (described in detail below) is designated as the heating region 120. The heating region of the chip substrate is placed within a temperature-controlled chip bath. For example, by placing the heating region of the chip substrate within the chip bath, the temperature of the heating region on the chip substrate can be controlled. One feasible approach is to place the heating region of the chip substrate within a temperature-controlled chip bath, and by controlling the temperature within the chip bath, to maintain the heating region of the chip substrate at a preset temperature. The preset temperature can be set according to specific circumstances, such as the type, crystal form, size, or reaction time of the target product.

[0045] In this embodiment of the application, the microreactor chip further includes flow channels disposed on the chip substrate 110, the flow channels including a first channel 130 and a second channel 140, the first channel 130 and the second channel 140 forming a mixing cavity 160 at the connection point.

[0046] Specifically, the flow channel is located inside the chip substrate 110. An inlet is provided on the chip substrate, through which the solution can flow into the interior of the chip substrate. It is understood that the solution can flow along the flow channel under driving action, and mixing and chemical reactions can occur within the flow channel.

[0047] The mixing cavity 160 refers to the confluence of the first channel 130 and the second channel 140, that is, the intersection of the first channel 130 and the second channel 140. In the embodiments of this application, the first channel 130 and the second channel 140 converge at their ends and form the mixing cavity 160 at their common end.

[0048] The volume of the mixing chamber 160 can be set according to specific circumstances. It is understood that since the first channel 130 and the second channel 140 are interconnected, a mixing and converging point is formed at the connection point. Solution 1 (e.g., a cation precursor solution) can flow into the mixing chamber 160 through the first channel inlet 1310. Solution 2 (e.g., anion precursor solution) flows into the mixing chamber 160 through the second channel inlet 1410. In this embodiment, solutions 1 and 2 can flow into the mixing chamber 160 through the first channel 130 and the second channel 140 respectively. Since solutions 1 and 2 are in a separated state before flowing into the mixing chamber 160, they will not undergo a chemical reaction even if they are heated to a certain temperature. Solutions 1 and 2 meet at the mixing chamber 160 and mix to form a reaction solution, which can only undergo a chemical reaction under certain conditions (e.g., when heated to the reaction temperature).

[0049] In this embodiment, the portion of the first channel 130 and / or the second channel 140 between its inlet and the mixing chamber 160 is at least partially located within the heating region 120. It is understood that because the first channel 130 and / or the second channel 140 are at least partially located within the heating region 120, the solution flowing through the heating region 120 can be heated, resulting in different temperatures when the solution flows into the mixing chamber 160 via the first channel 130 or the second channel 140. For example, the temperature of solution 1 flowing into the mixing chamber 160 via the inlet of the first channel 130 is T1. The temperature of solution 2 flowing into the mixing chamber 160 via the inlet of the second channel 140 is T2, where T1 and T2 are different temperature values. One feasible approach is to control the time the solution spends flowing through the heating region within the first or second channel, thereby controlling the temperature of the solution flowing into the mixing chamber via the first or second channel.

[0050] Understandably, since solutions 1 and 2 flow into the mixing chamber 160 at different temperatures, the temperature within the mixing chamber can be adjusted and controlled by controlling the volume and temperature of solutions 1 and 2 flowing into the mixing chamber, thereby controlling the chemical reaction in the reaction solution. Taking quantum dot synthesis as an example, by controlling the temperature of the cationic precursor solution flowing into the mixing chamber 160 through the inlet of the first channel 130, and the temperature of the anionic precursor solution flowing into the mixing chamber 160 through the inlet of the second channel 140, a low-temperature solution (e.g., anionic precursor solution) can be injected into a hot solution (e.g., cationic precursor solution), thus allowing the nucleation and growth of quantum dots to be separated.

[0051] In this application, a first channel 130, a second channel 140, and a heating region 120 are provided on a chip substrate 110, and the portion of the first channel 130 and / or the second channel 140 between its inlet and the mixing chamber 160 is at least partially located within the heating region 120. The temperature of the solution (e.g., a cation precursor solution) flowing into the mixing chamber 160 through the inlet of the first channel 130 is T1, and the temperature of the solution (e.g., anion precursor solution) flowing into the mixing chamber 160 through the inlet of the second channel 140 is T2, and T1 and T2 are different temperature values. Compared with the prior art microreactor chips, when used for microreactors, the temperature of the solution in the mixing chamber can be flexibly controlled when solutions flowing in through different channels are mixed in the mixing chamber.

[0052] The microreaction chip in this application can be used for quantum dot synthesis. The microreaction chip can serve as a container for quantum dot synthesis. The structure of the microreaction chip in this application is further illustrated below using quantum dot synthesis as an example.

[0053] As described in the background art, current microreactor chips primarily employ two liquid introduction methods for quantum dot synthesis: one method involves first filling a single syringe with all premixed anion and cation precursor solutions, then using the syringe to push the mixture into a heating zone at a target flow rate for reaction. The other method involves filling different ion precursor solutions separately into different syringes, then setting a target flow rate based on the molar ratio of the different ions. All ion solutions then converge at a confluence point in the tubing, and the mixed solution is then pushed into the heating zone to begin the reaction. In this synthesis method, because the different ion precursor solutions are mixed and heated in the same space, quantum dot nucleation and growth occur simultaneously, making it difficult to synthesize high-quality fluorescent quantum dot materials with narrow size distributions.

[0054] When the microreaction chip 100 provided in this application is used for quantum dot synthesis, the anion precursor solution can flow into the mixing chamber 160 through one of the first channel 130 or the second channel 140, and the cation precursor solution can flow into the mixing chamber 160 through the other of the first channel 130 or the second channel 140. For example, the temperature of the cationic precursor solution flowing into the mixing chamber 160 through the inlet of the first channel 130 is T1, and the temperature of the anionic precursor solution flowing into the mixing chamber 160 through the inlet of the second channel 140 is T2. By controlling the temperatures T1 and T2, the temperatures of the cationic and anionic precursor solutions in the mixing chamber 160 can be controlled. For example, when the nucleation temperature of the cationic and anionic precursor solutions (i.e., the reaction solution) is 300°C, the temperature of the cationic precursor solution flowing into the mixing chamber 160 through the inlet of the first channel 130 is controlled to be between 300°C and 310°C, and the temperature of the anionic precursor solution flowing into the mixing chamber through the inlet of the second channel 140 is controlled to be at a low temperature (e.g., 25°C). This allows for the rapid injection of a low-temperature anionic precursor solution into the hot cationic precursor solution, so that the anionic and cationic precursor solutions can rapidly undergo a nucleation reaction when they meet in the mixing chamber. Meanwhile, since the temperature of the cation precursor solution is only slightly higher than the nucleation temperature, after the low-temperature anion precursor solution is injected, the temperature of the reaction solution in the mixing chamber drops rapidly to below the nucleation temperature, terminating the quantum dot nucleation. This causes the quantum dot nucleation and growth to separate, which is beneficial for synthesizing high-quality fluorescent quantum dot materials with narrow size distribution.

[0055] Please see Figure 1 In some embodiments of this application, a non-heated region 170 is further provided on the chip substrate 110. A first channel 130 is disposed in the non-heated region 170, and a second channel is at least partially located within a heated region 120. The heated region 120 is adjacent to the non-heated region 170, and a mixing chamber 160 is disposed within the heated region 120 and adjacent to the boundary between the heated region 120 and the non-heated region 170. This structural arrangement simplifies the structure of the microreaction chip, facilitates the control of the liquid temperature within the mixing chamber 160, and is beneficial for synthesizing high-quality fluorescent quantum dot materials with narrow size distribution.

[0056] Understandably, since the first channel 130 is located within the non-heated region 170, and the second channel 140 is at least partially located within the heated region 120, with the heated region 120 and the non-heated region 170 adjacent to each other, the mixing chamber 160 is located at the boundary between the heated region 120 and the non-heated region 170. Solution 1 can flow into the first channel through the inlet of the first channel 130 and then into the mixing chamber 160 at room temperature. Solution 2 can flow into the second channel through the inlet of the second channel 140, and after being heated to a preset temperature while flowing through the heated region 120 in the second channel, it flows into the mixing chamber 160. Because the heated region 120 and the non-heated region 170 are adjacent to each other, and the mixing chamber is located at the boundary between the heated and non-heated regions, both solution 1 and solution 2 can flow into the mixing chamber under constant temperature conditions, which is beneficial to improving the controllability of the temperature within the mixing chamber. When used for quantum dot synthesis, solution 2 can be heated and flow into mixing chamber 160 at a higher preset temperature. Solution 1 can be injected into solution 2 at a higher temperature under room temperature conditions. The high temperature difference between solution 1 and solution 2 can rapidly terminate the nucleation reaction, which is beneficial for synthesizing high-quality fluorescent quantum dot materials with narrow size distribution.

[0057] Specifically, the non-heated area 170 is disposed above the chip substrate 110, the heated area 120 is disposed below the chip substrate 110 adjacent to the non-heated area 170, and the mixing chamber 160 is disposed at the junction of the heated area 120 and the non-heated area 170 and located on the right side of the chip substrate.

[0058] There are two first channels 130 and two second channels 140. Each first channel and each second channel has one inlet. The size of each inlet can be set according to specific conditions, for example, the diameter of the inlet can be 0.2mm to 1.3mm. The size of each inlet can be the same or different.

[0059] Multiple inlets are located at the end of the non-heated zone 170 away from the heated zone 120, a configuration that improves injection efficiency. Furthermore, the spacing between adjacent inlets is 2mm to 25mm. The spacing between adjacent inlets can be the same or different.

[0060] Liquid can flow into the corresponding first channel 130 or second channel 140 through this inlet. The number of first channels 130 or second channels 140 can be set according to specific circumstances. For example, in some embodiments, there is one first channel 130 and two second channels 140; in yet another embodiment, there is one first channel and one second channel. This is not limited here. Furthermore, multiple inlets are equally spaced at one end of the non-heated area 170 away from the heated area 120. This structural arrangement helps to improve the liquid injection efficiency.

[0061] Each first channel 130 includes a first segment extending vertically from its inlet, a horizontal segment extending from the end of the first segment toward the side where the mixing chamber is located, and a third segment extending vertically from the end of the horizontal segment to the mixing chamber. Each second channel 140 includes a first portion disposed in a non-heated area and a bent second portion disposed in a heated area. The structure of the first portion is similar to that of the first channel, and the two ends of the second portion are respectively connected to the end of the first portion and the mixing chamber. This structural arrangement facilitates a more regular flow channel structure and improves the volume of the chip substrate.

[0062] The volume of each first pipe 130, that is, the volume at the junction of the inlet of the first pipe and the mixing chamber, can be set according to the specific situation. It can be the same or different. For example, the volume of the first pipe is 0.001mm to 0.01ml.

[0063] The volume of each second pipe 140, that is, the volume from the inlet of the second pipe to the junction of the mixing chamber, can be set according to the specific situation. It can be the same or different. For example, the volume of the second pipe is 0.01mm to 0.1ml.

[0064] In some embodiments of this application, the flow channel further includes a third channel 150, which connects the outlet 1510 of the flow channel and the mixing chamber 160. The third channel includes a meandering pipeline portion 1520 disposed in the heating region. This structural arrangement is beneficial for increasing the length of the third channel 150 in the heating region 120, and for increasing the flow time of the reaction liquid in the heating region 120 and the volume of the chip substrate 110.

[0065] Specifically, the heating zone includes a first edge adjacent to the non-heating zone and a second edge of the non-heating zone. The third channel originates from the mixing chamber and extends in a zigzag pattern between the first and second edges, forming a meandering pipeline section. The outlet of the third channel is located on the side of the inlet in the non-heating zone, away from the mixing chamber. This outlet communicates with the end of the meandering pipeline section. The volume of each third pipe, i.e., the volume from the outlet of the third pipe to the boundary of the mixing chamber, can be set according to specific circumstances; for example, the volume of the third pipe can be from 0.1 mm to 2.0 ml.

[0066] In some embodiments of this application, a protruding structure is provided on the inner sidewall of the flow channel.

[0067] Understandably, liquid flow in conventional microreaction chips is primarily achieved through pressure pumps. When the internal channels of the chip are smooth, hollow cylindrical channels, the liquid flow becomes parabolic under pump-driven pressure. As the liquid flows through the microchannels, the fluid velocity near the channel walls is very low, resulting in a longer residence time, while the fluid velocity in the center of the channel is faster, resulting in a shorter residence time. This is highly detrimental to quantum dot synthesis, which requires high temperatures. The varying heating times of the fluid within the channel lead to larger grains near the walls, resulting in a wider size distribution in the final product. In this embodiment, the inventors discovered that a raised structure on the inner wall of the microreaction chip's flow channel creates an uneven, three-dimensional structure. This effectively addresses the influence of the velocity difference between the center and edges of the channel, improving the mixing degree of ions in the reaction solution and facilitating the synthesis of high-quality fluorescent quantum dot materials with a narrow size distribution.

[0068] This application further improves a micro-reaction control method, including,

[0069] Step S1: Provide a micro-reaction chip, which includes a chip substrate and flow channels disposed on the chip substrate; the chip substrate has a heating area; the flow channels include a first channel and a second channel, and the first channel and the second channel form a mixing cavity at the connection point.

[0070] It should be noted that the structure of the microreaction chip has been described in detail above and will not be repeated here.

[0071] Step S2: Drive the first solution to flow into the mixing chamber from the inlet of the first channel. The temperature of the first solution when it flows into the mixing chamber is T1.

[0072] Step S3: Drive the second solution to flow into the mixing chamber from the inlet of the second channel. The temperature of the second solution when it flows into the mixing chamber is T2; where T1 and T2 are different temperature values.

[0073] It is understandable that the temperature of the first solution flowing into the mixing chamber through the inlet of the first channel is T1, and the temperature of the second solution flowing into the mixing chamber through the inlet of the second channel is T2, and T1 and T2 are different temperature values. Compared with the microreactor chips in the prior art, when different solutions flowing in through different channels are mixed in the mixing chamber during microreactors, the temperature of the reaction liquid in the mixing chamber can be flexibly controlled, thereby controlling the chemical reaction in the mixing chamber.

[0074] The microreaction control method in the embodiments of this application can be used for the synthesis of quantum dots.

[0075] Specifically, the first solution includes an anion precursor solution, the second solution includes a cation precursor solution, and the first and second solutions are mixed in a mixing chamber to form a reaction solution; wherein, T1 or T2 is higher than the nucleation temperature of the reaction solution, and the temperature of the reaction solution in the mixing chamber is lower than the nucleation temperature.

[0076] It is understood that the anionic precursor solution can flow into the mixing chamber through either the first or the second channel, and the cationic precursor solution can flow into the mixing chamber through the other of the first or the second channel. For example, the temperature of the cationic precursor solution flowing into the mixing chamber through the inlet of the first channel is T1, and the temperature of the anionic precursor solution flowing into the mixing chamber through the inlet of the second channel is T2. By controlling temperatures T1 and T2, the temperatures of the cationic and anionic precursor solutions within the mixing chamber can be controlled. For example, when the nucleation temperature of the cationic and anionic precursor solutions (i.e., the reaction solution) is 300°C, the temperature of the cationic precursor solution flowing into the mixing chamber through the inlet of the first channel can be controlled to be between 300°C and 310°C, and the temperature of the anionic precursor solution flowing into the mixing chamber through the inlet of the second channel can be controlled to be at a low temperature (e.g., 25°C). This allows for the rapid injection of a low-temperature anionic precursor solution into the hot cationic precursor solution, enabling a rapid nucleation reaction when the anionic and cationic precursor solutions meet within the mixing chamber. Meanwhile, since the temperature of the cation precursor solution is only slightly higher than the nucleation temperature, after the low-temperature anion precursor solution is injected, the temperature of the reaction solution in the mixing chamber drops rapidly to below the nucleation temperature, terminating the quantum dot nucleation. This causes the quantum dot nucleation and growth to separate, which is beneficial for synthesizing high-quality fluorescent quantum dot materials with narrow size distribution.

[0077] In this embodiment, the flow channel further includes a third channel, which connects the outlet of the flow channel and the mixing chamber. The third channel includes a meandering pipeline section disposed in the heating region. The control method further includes driving the reaction liquid to flow along the meandering pipeline section at a preset temperature. This structural arrangement is beneficial for increasing the length of the third channel in the heating region and for increasing the flow time of the reaction liquid in the heating region, thereby providing sufficient growth time for the quantum dots and facilitating the synthesis of high-quality fluorescent quantum dot materials with narrow size distribution.

[0078] Another aspect of this application improves a method for fabricating a microreaction chip, providing a chip substrate with a heating region on the chip substrate; etching the chip substrate to form flow channels on the chip substrate; wherein the flow channels include a first channel and a second channel, the first channel and the second channel forming a mixing cavity at their connection point, and the first channel and / or the second channel being at least partially located within the heating region; the temperature of the solution flowing into the mixing cavity through the inlet of the first channel is T1, the temperature of the solution flowing into the mixing cavity through the inlet of the second channel is T2, and T1 and T2 are different temperature values.

[0079] The etching process to form flow channels on the chip substrate can be a method already disclosed in the prior art, and is not limited here.

[0080] This application also provides a microreaction system comprising any of the microreaction chips described above. Furthermore, the microreaction system may also include a controller module and an injection pump, etc. For other components of the microreaction system besides the microreaction chip, please refer, for example, to the description in CN202011628120.8. The entire contents of CN202011628120.8 are incorporated herein by reference.

[0081] This application provides a microreaction chip, a fabrication method, and a microreaction control method, which are described in detail below. The above description details the microreaction chip, fabrication method, and microreaction control method provided in this application. Specific examples are used to illustrate the principles and implementation methods of the invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the invention.

Claims

1. A method for controlling the synthesis of quantum dot materials, characterized in that, include, A microreactor chip is provided, the microreactor chip including a chip substrate and flow channels disposed on the chip substrate; a heating region is provided on the chip substrate; the flow channels include a first channel and a second channel, the first channel and the second channel forming a mixing cavity at a connection point; at least a portion of the first channel and / or the second channel between their respective inlets and the mixing cavity is located within the heating region. The anion precursor solution is driven to flow into the mixing chamber from the inlet of the first channel, and the temperature at which it flows into the mixing chamber is T1; The cationic precursor solution is driven to flow into the mixing chamber from the inlet of the second channel, and the temperature at which it flows into the mixing chamber is T2; In this process, the anionic precursor solution and the cationic precursor solution are mixed in the mixing chamber to form a reaction solution; T1 or T2 is higher than the nucleation temperature of the reaction solution, and T1 and T2 are different temperature values; the temperature of the reaction solution in the mixing chamber is lower than the nucleation temperature; after the anionic precursor solution is injected, the temperature of the reaction solution in the mixing chamber drops below the nucleation temperature, and quantum dot nucleation terminates, thus separating the quantum dot nucleation and growth. The flow channel also includes a third channel, which connects the outlet of the flow channel and the mixing chamber. The third channel includes a meandering pipeline section disposed in the heating area.

2. The control method as described in claim 1, characterized in that, The chip substrate also has a non-heated area, the first channel is disposed in the non-heated area, the second channel is at least partially located in the heated area, the heated area is adjacent to the non-heated area, the mixing chamber is disposed in the heated area and adjacent to the boundary between the heated area and the non-heated area.

3. The control method as described in claim 1, characterized in that, The inner wall of the flow channel is provided with a protruding structure.

4. The control method as described in claim 2, characterized in that, The non-heated area is located on the upper part of the chip substrate, and the heated area is located at the end of the chip substrate away from the non-heated area. The entrances of the first channel and the second channel are both located on one side of the non-heated area.

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