Micro-mixing channel and micro-fluidic chip for preparing nano-pesticide

Abstract

The invention belongs to the field of micro-fluidic chips, and particularly relates to a micro-mixing channel for preparing nano-pesticide and a micro-fluidic chip. The micro-mixing channel comprises at least two feed ports, at least two inlet channels communicated with the feed ports, an inlet communication channel communicated with the other ends, far away from the feed ports, of all the inlet channels, at least two micro-mixing units communicated with the inlet communication channel, and an outlet communication channel communicated with the last micro-mixing unit, the discharge hole is communicated with the outlet communication channel; the micro-mixing unit is a contraction-expansion mixing chamber internally provided with a date-pit-shaped baffle, and the contraction-expansion mixing chamber comprises an inlet of the contraction-expansion mixing chamber, a middle structure internally provided with the date-pit-shaped baffle and an outlet of the contraction-expansion mixing chamber; and the previous micro-mixing unit is communicated with the inlet of the contraction-expansion mixing chamber of the next micro-mixing unit through the outlet of the contraction-expansion mixing chamber. The micro-mixing channel and the micro-fluidic chip can be used for preparing nano pesticides, and are simple in structure, convenient to process and wide in application range.

Description

Technical Field

[0001] The invention belongs to the field of microfluidic chips, and in particular relates to a micro-mixing channel and a microfluidic chip for preparing nanopesticides. Background Art

[0002] In recent years, nanopesticides have shown great potential in achieving pesticide reduction and efficiency improvement, increasing food production, and protecting the ecological environment, and have become the mainstream of green pesticide innovation and development. However, nanopesticides lack the technology and special equipment that can consistently produce stable and controllable nanoformulations from early development to transformation and application, and urgently need to break through the key challenges and technical bottlenecks of large-scale industrialization. Therefore, the development of new green processing technologies and equipment that can maintain the uniformity and stability of nanopesticides in large-scale production is the premise and guarantee for promoting the promotion and application of nanopesticides.

[0003] Microfluidics is a repeatable and scalable technology that can precisely control the size, morphology and stability of nanoparticles. It has been proven to have the ability to efficiently, stably and controllably produce nanopesticides. Therefore, it has the potential to solve a series of bottleneck problems such as the difficult controllable preparation and scale-up of nanopesticides.

[0004] Microfluidic chips are an indispensable and key part of microfluidic systems, used to quickly and evenly mix fluids in channels and precisely control the reaction process. Compared with traditional reactors, microfluidic chips have the characteristics of large surface area to volume ratio, high mixing efficiency, low reagent consumption, and high controllability. In addition, the throughput of traditional reactions is determined by the size of the reaction vessel, while the scale of microfluidic chip reactions is determined by the flow rate and running time, and can continuously and stably output products of a certain quality.

[0005] Therefore, there is an urgent need in the art to design a new microfluidic chip for preparing nanopesticides that can improve preparation efficiency and meet production needs. Summary of the invention

[0006] The purpose of the present invention is to provide a micro-mixing channel and a microfluidic chip for preparing nanopesticides.

[0007] Based on the above problems, the purpose of the present invention is to provide a micro-mixing channel and a microfluidic chip for preparing nanopesticides, which have a simple structure, convenient processing, and a wide range of applications. The micro-mixing channel and the microfluidic chip of the present invention strengthen the mixing of fluids by combining the two structural designs of the contraction-expansion mixing chamber and the jujube-shaped baffle, and have application potential and prospects in the construction of green nanopesticides.

[0008] In the first aspect of the present invention, a micro - mixing channel is provided. The micro - mixing channel includes at least two feed ports, at least two inlet channels communicating with the feed ports, an inlet connection channel communicating with the other ends of all the inlet channels away from the feed ports, at least two micro - mixing units communicating with the inlet connection channel, an outlet connection channel communicating with the last micro - mixing unit, and a discharge port communicating with the outlet connection channel.

[0009] The micro - mixing unit is a contraction - expansion mixing chamber with a date - pit - shaped baffle inside. The contraction - expansion mixing chamber includes an inlet of the contraction - expansion mixing chamber, a middle structure with a date - pit - shaped baffle inside, and an outlet of the contraction - expansion mixing chamber. The outlet of the contraction - expansion mixing chamber of the previous micro - mixing unit communicates with the inlet of the contraction - expansion mixing chamber of the next micro - mixing unit. The inlet connection channel communicates with the inlet of the contraction - expansion mixing chamber of the first micro - mixing unit, and the outlet connection channel communicates with the outlet of the contraction - expansion mixing chamber of the last micro - mixing unit.

[0010] In the second aspect of the present invention, a microfluidic chip is provided. The microfluidic chip includes at least two feed ports, at least two inlet channels communicating with the feed ports, an inlet connection channel into which all the inlet channels lead at the other ends away from their feed ports, at least two micro - mixing unit assemblies communicating with the inlet connection channel, a vortex mixing flow channel connecting adjacent two micro - mixing unit assemblies, an outlet connection channel communicating with the last micro - mixing unit assembly, and a discharge port communicating with the outlet connection channel.

[0011] The micro - mixing unit assembly includes at least two micro - mixing units. The micro - mixing unit is a contraction - expansion mixing chamber with a date - pit - shaped baffle inside. The contraction - expansion mixing chamber includes an inlet of the contraction - expansion mixing chamber, a middle structure with a date - pit - shaped baffle inside, and an outlet of the contraction - expansion mixing chamber. The outlet of the contraction - expansion mixing chamber of the previous micro - mixing unit communicates with the inlet of the contraction - expansion mixing chamber of the next micro - mixing unit.

[0012] The inlet of the contraction - expansion mixing chamber of the first micro - mixing unit in the first micro - mixing unit assembly communicates with the inlet connection channel, and the outlet of the contraction - expansion mixing chamber of the last micro - mixing unit in the last micro - mixing unit assembly communicates with the outlet connection channel.

[0013] In the third aspect of the present invention, a method for preparing the micro - mixing channel according to the first aspect of the present invention and the microfluidic chip according to the second aspect of the present invention is provided. The method includes processes selected from the following group: etching, MEMS manufacturing process, 3D printing, machining, and ultrafast laser processing.

[0014] In a fourth aspect of the present invention, there is provided the micro-mixing channel described in the first aspect of the present invention and the microfluidic chip described in the second aspect of the present invention, wherein the micro-mixing channel and / or the microfluidic chip has an integral structure; or the micro-mixing channel and / or the microfluidic chip has a split structure, the split structure includes an upper cover plate and a lower bottom plate, and the structures for forming the outer walls of the respective channels and chambers are arranged on the lower bottom plate, and the upper cover plate is covered with the lower bottom plate to form the respective channels and chambers.

[0015] In one or more embodiments, the materials of the integral structure, the upper cover plate and the lower bottom plate are each independently selected from one or more of borosilicate glass, quartz glass, acrylonitrile-butadiene-styrene copolymer, polyamide, polybutylene terephthalate, polyether and polymethyl methacrylate.

[0016] In a fifth aspect of the present invention, there is provided the use of the micro-mixing channel described in the first aspect of the present invention and the microfluidic chip described in the second aspect of the present invention in the preparation of nano-pesticides.

[0017] In one or more embodiments, the nano-pesticides are selected from one or more of lambda-cyhalothrin nano-pesticides, emamectin benzoate nano-pesticides, spinosad nano-pesticides, chlorantraniliprole nano-pesticides, imidacloprid nano-pesticides, tebuconazole nano-pesticides and pyraclostrobin nano-pesticides. Description of the Drawings

[0018] Figure 1 It is a two-dimensional schematic diagram of a micro-mixing channel for preparing nano-pesticides in some embodiments of the present invention.

[0019] Figure 2 It is a partial enlarged view of a micro-mixing unit of a micro-mixing channel for preparing nano-pesticides in some embodiments of the present invention; wherein, the width of the middle structure of the contraction-expansion mixing chamber is a, the length of the contraction-expansion mixing chamber is b, the maximum length of the date-pit-shaped baffle is c, the maximum width of the date-pit-shaped baffle is d, and the included angle between the central axes of the two arc surfaces of the date-pit-shaped baffle and the outlet wall surface of the contraction-expansion mixing chamber is θ.

[0020] Figure 3 It is a three-dimensional schematic diagram of a micro-mixing channel for preparing nano-pesticides in some embodiments of the present invention.

[0021] Figure 4 It is a two-dimensional schematic diagram of a micro-mixing channel in a microfluidic chip for preparing nano-pesticides in some embodiments of the present invention.

[0022] Figure 53D schematic diagram of the micro-mixing channel in a microfluidic chip for preparing nano-pesticides in some embodiments of the present invention.

[0023] Figure 6 COMSOL simulation diagram of a microfluidic chip for preparing nano-pesticides in Example 4 of the present invention.

[0024] Figure 7 Physical diagram of a microfluidic chip for preparing nano-pesticides in some embodiments of the present invention.

[0025] Figure 8 Transmission electron microscope image of the lambda-cyhalothrin nano-pesticide prepared in Example 6.

[0026] In the drawings, the same components are denoted by the same reference numerals. The drawings are not drawn to actual scale. The reference numerals are explained as follows: 1 is the first feed port, 2 is the second feed port, 3 is the inlet channel, 4 is the inlet connection channel, 5 is the contraction-expansion mixing chamber, 6 is the jujube-shaped baffle, 7 is the outlet connection channel, 8 is the discharge port, and 9 is the vortex mixing channel. Detailed Description of the Invention

[0027] To enable those skilled in the art to understand the features and effects of the present invention, the following provides a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention. In case of conflict, the definition in this specification shall prevail.

[0028] The theories or mechanisms described and disclosed herein, whether correct or incorrect, shall not limit the scope of the present invention in any way, that is, the content of the present invention can be implemented without being limited by any specific theory or mechanism.

[0029] In this article, terms such as "comprising", "including", "containing" and similar terms cover the meanings of "consisting essentially of" and "consisting of". For example, when this article discloses that "A comprises B and C", it should be considered that "A consists essentially of B and C" and "A consists of B and C" have been disclosed herein.

[0030] In this article, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents and concentrations, are only for the sake of brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be regarded as having covered and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0031] In this article, unless otherwise specified, the percentage refers to the mass percentage and the ratio refers to the mass ratio.

[0032] In this document, when describing embodiments or examples, it should be understood that it is not intended to limit the present invention to these embodiments or examples. On the contrary, all alternatives, improvements, and equivalents of the methods and materials described in the present invention are intended to be covered within the scope defined by the claims.

[0033] In this document, for the sake of brevity of description, not all possible combinations of all technical features in each embodiment or example are described. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered to be within the scope described in this specification.

[0034] In this document, terms such as "upper", "lower", "front", "rear", "left", "right", "length", "width", "depth", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only keywords determined for the convenience of describing the structural relationships of various components or elements of the present invention, and do not specifically refer to that each component or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0035] In this document, terms such as "connected", "joined", "communicated" should be understood in a broad sense. For example, it can be a fixed connection or an integral connection; it can be directly connected or connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances, and it should not be construed as a limitation to the present invention.

[0036] In this document, terms such as "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. The specific meanings of the above terms in the present invention can be understood according to specific circumstances, and it should not be construed as a limitation to the present invention.

[0037] In this document, the meaning of "several" is more than one, the meaning of "multiple" is more than two, "greater than", "less than", etc. are understood as not including the number itself, and "above", "below", etc. are understood as including the number itself.

[0038] The medium in the micro-mixing channels and microfluidic chips of the present invention can be a gas or a liquid, and the micro-mixing channels and microfluidic chips of the present invention can be used for physical or chemical reactions of the medium in the micro-mixing channels.

[0039] The micro-mixing channels and microfluidic chips of the present invention have a three-dimensional structure and are generally flat in shape.

[0040] In the present invention, each component of the micro-mixing channel and the microfluidic chip has a top surface and a bottom surface. The top surface and the bottom surface of the same component are parallel to each other. In the present invention, the depth of each component refers to the distance between the top surface and the bottom surface of each component, the length of each component refers to the maximum dimension of each component in the overall flow direction of the material, and the width of each component refers to the dimension of each component in the direction perpendicular to the overall flow direction of the material and perpendicular to the depth direction of the component.

[0041] In the present invention, the combination of a contraction-expansion mixing chamber and a date-pit-shaped baffle is used to strengthen the mixing of fluids. Therefore, the present invention provides a micro-mixing unit including two structural designs: a contraction-expansion mixing chamber and a date-pit-shaped baffle.

[0042] As Figure 2 shown, the micro-mixing unit is a contraction-expansion mixing chamber with a date-pit-shaped baffle inside. The contraction-expansion mixing chamber includes an inlet of the contraction-expansion mixing chamber, a middle structure with a date-pit-shaped baffle inside, and an outlet of the contraction-expansion mixing chamber. The middle structure of the contraction-expansion mixing chamber has two arc-shaped side walls, which can enhance fluid mixing. Both the inlet and the outlet of the contraction-expansion mixing chamber contain two parallel wall surfaces, which are connected to the arc-shaped side walls of the middle structure. The width of the middle structure of the contraction-expansion mixing chamber is greater than the width of the inlet and the outlet of the contraction-expansion mixing chamber. This design can strengthen mixing by changing the cross-sectional area of the channel. The date-pit-shaped baffle is composed of two arc surfaces. The included angle θ between the central axis of the two arc surfaces forming the date-pit-shaped baffle and the outlet wall surface of the contraction-expansion mixing chamber is 30° - 60°, such as 35°, 40°, 45°, 50°, 55°, 60°, or within the range composed of any two values. This design divides the main flow into two sub-flows through splitting and recombination and then recombines and collides to generate chaotic flow, which can significantly enhance the mixing effect.

[0043] The present invention provides a micro-mixing channel including the above-mentioned micro-mixing unit. The micro-mixing channel includes at least two feed ports, at least two inlet channels communicating with the feed ports, an inlet communication channel communicating with the other ends of all the inlet channels far from the feed ports, at least two micro-mixing units communicating with the inlet communication channel, an outlet communication channel communicating with the last micro-mixing unit, and a discharge port communicating with the outlet communication channel.

[0044] Specifically, the previous micro-mixing unit communicates with the inlet of the contraction-expansion mixing chamber of the next micro-mixing unit through the outlet of its contraction-expansion mixing chamber; the inlet communication channel communicates with the inlet of the contraction-expansion mixing chamber of the first micro-mixing unit; the outlet communication channel communicates with the outlet of the contraction-expansion mixing chamber of the last micro-mixing unit.

[0045] In the micro-mixing channel of the present invention, the number of micro-mixing units can be 2 - 15, such as 3, 5, 7, 9, 11, 13.

[0046] In some embodiments, the micro-mixing channel includes two feed ports and two inlet channels respectively connected to the two feed ports. Preferably, the included angle between the two inlet channels is 45° - 120°, such as 50°, 60°, 70°, 80°, 90°, 100°, 110°, 120°.

[0047] In the micro-mixing channel of the present invention, the width of the feed port can be 0.1 - 2 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm.

[0048] In the micro-mixing channel of the present invention, the depth of the feed port can be 0.1 - 2 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm.

[0049] In the micro-mixing channel of the present invention, the width of the inlet channel is 0.1 - 2 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm.

[0050] In the micro-mixing channel of the present invention, the depth of the inlet channel is 0.1 - 2 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm.

[0051] In the micro-mixing channel of the present invention, the length of the inlet channel is 2 - 12 mm, such as 3 mm, 5 mm, 7 mm, 9 mm, 11 mm.

[0052] In the micro-mixing channel of the present invention, the width of the inlet connecting channel is 0.1 - 2 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm.

[0053] In the micro-mixing channel of the present invention, the depth of the inlet connecting channel is 0.1 - 2 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm.

[0054] In the micro-mixing channel of the present invention, the length of the inlet connecting channel is 0.5 - 10 mm, such as 0.8 mm, 1 mm, 3 mm, 5 mm, 7 mm, 9 mm.

[0055] In the micro-mixing channel of the present invention, the width of the outlet connecting channel is 0.1 - 2 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm.

[0056] In the micro-mixing channel of the present invention, the depth of the outlet connecting channel is 0.1 - 2 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm.

[0057] In the micro - mixing channel of the present invention, the length of the outlet - connecting channel is 0.5 - 10 mm, such as 0.8 mm, 1 mm, 3 mm, 5 mm, 7 mm, 9 mm.

[0058] In the micro - mixing channel of the present invention, the width of the discharge port is 0.1 - 2 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm.

[0059] In the micro - mixing channel of the present invention, the depth of the discharge port is 0.1 - 2 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm.

[0060] In the micro - mixing channel of the present invention, the width of the middle structure of the contraction - expansion mixing chamber is 1 - 5 mm, such as 2 mm, 3 mm, 4 mm.

[0061] In the micro - mixing channel of the present invention, the depth of the contraction - expansion mixing chamber is 0.1 - 2 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm.

[0062] In the micro - mixing channel of the present invention, the length of the contraction - expansion mixing chamber is 2 - 8 mm, such as 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm.

[0063] In the micro - mixing channel of the present invention, the maximum width of the date - pit - shaped baffle is 0.1 - 2 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm.

[0064] In the micro - mixing channel of the present invention, the depth of the date - pit - shaped baffle is 0.1 - 2 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm.

[0065] In the micro - mixing channel of the present invention, the maximum length of the date - pit - shaped baffle is 0.2 - 4 mm, such as 0.5 mm, 0.8 mm, 1 mm, 2 mm, 3 mm, 4 mm.

[0066] In some embodiments, in the micro - mixing channel of the present invention, the depths of each inlet channel, inlet - connecting channel, each contraction - expansion mixing chamber, each date - pit - shaped baffle, and outlet - connecting channel are the same.

[0067] In some embodiments, in the micro - mixing channel of the present invention, the depths of each feed port, each inlet channel, inlet - connecting channel, each contraction - expansion mixing chamber, each date - pit - shaped baffle, outlet - connecting channel, and discharge port are the same.

[0068] The present invention also provides a microfluidic chip including the above-mentioned micro mixing unit. The microfluidic chip includes at least two feed ports, at least two inlet channels communicating with the feed ports, an inlet communication channel to which all the inlet channels lead at the other end far from their feed ports, at least two micro mixing unit assemblies communicating with the inlet communication channel, a vortex mixing flow channel connecting adjacent two micro mixing unit assemblies, an outlet communication channel communicating with the last micro mixing unit assembly, and a discharge port communicating with the outlet communication channel. The micro mixing unit assembly includes at least two of the above-mentioned micro mixing units.

[0069] Specifically, the outlet of the contraction-expansion mixing chamber of the previous micro mixing unit communicates with the inlet of the contraction-expansion mixing chamber of the next micro mixing unit; the inlet of the contraction-expansion mixing chamber of the first micro mixing unit in the first micro mixing unit assembly communicates with the inlet communication channel; the outlet of the contraction-expansion mixing chamber of the last micro mixing unit in the last micro mixing unit assembly communicates with the outlet communication channel. Each micro mixing unit assembly is arranged in a parallel and circuitous manner, and the head and tail of the latter micro mixing unit assembly are respectively aligned with the tail and head of the previous micro mixing unit assembly.

[0070] In the present invention, the vortex mixing flow channel has an inlet and an outlet. In some embodiments, the vortex mixing flow channel is arc-shaped. The vortex mixing flow channel being arc-shaped means that when observed in the depth direction, the vortex mixing flow channel is arc-shaped as a whole. In some embodiments, the angle between the inlet and the outlet of the vortex mixing channel is 180°, that is, the orientations of the inlet and the outlet are opposite.

[0071] In the microfluidic chip of the present invention, the number of micro mixing unit assemblies can be 2 - 10, such as 5, 6, 8, 9, 10.

[0072] In the microfluidic chip of the present invention, the number of micro mixing units included in each micro mixing unit assembly can be 2 - 15, such as 3, 5, 7, 9, 11, 13.

[0073] In some embodiments, the microfluidic chip includes two feed ports and two inlet channels respectively connected to the two feed ports. Preferably, the included angle between the two inlet channels is 45° - 120°, such as 50°, 60°, 70°, 80°, 90°, 100°, 110°, 120°.

[0074] The feed port, inlet channel, inlet communication channel, contraction-expansion mixing chamber, spindle-shaped baffle, outlet communication channel, and discharge port of the microfluidic chip of the present invention can have the same dimensions (length or maximum length, width or maximum width, depth, etc.) as those of the feed port, inlet channel, inlet communication channel, contraction-expansion mixing chamber, spindle-shaped baffle, outlet communication channel, and discharge port of the micro mixing channel of the present invention.

[0075] In the microfluidic chip of the present invention, the width of the vortex mixing channel is 0.1 - 2 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm.

[0076] In the microfluidic chip of the present invention, the depth of the vortex mixing channel is 0.1 - 2 mm, such as 0.2 mm, 0.5 mm, 1 mm, 1.5 mm.

[0077] In the microfluidic chip of the present invention, the length of the vortex mixing channel is 4 - 20 mm, such as 8 mm, 10 mm, 12 mm, 15 mm, 18 mm.

[0078] The micro - mixing channel and the microfluidic chip of the present invention can be prepared by conventional methods in the art. For example, the methods for preparing the micro - mixing channel and / or the microfluidic chip include processes selected from the following group: etching, MEMS manufacturing process, 3D printing, machining, and ultrafast laser processing.

[0079] In some embodiments, the micro - mixing channel and / or the microfluidic chip has an integral structure. In other embodiments, the micro - mixing channel and / or the microfluidic chip has a split structure, and the split structure includes an upper cover plate and a lower bottom plate. The structure for forming the outer walls of each channel and chamber is arranged on the lower bottom plate, and the upper cover plate is covered with the lower bottom plate to form each channel and chamber.

[0080] The materials of the above - mentioned integral structure, upper cover plate, and lower bottom plate are each independently selected from one or more of borosilicate glass, quartz glass, acrylonitrile - butadiene - styrene copolymer, polyamide, polybutylene terephthalate, polyether, and polymethyl methacrylate, and preferably borosilicate glass.

[0081] Method

[0082] The present invention also provides a method for preparing nano - pesticides, which uses the micro - mixing channel or microfluidic chip of the present invention for preparation. It can be prepared by conventional methods for preparing nano - pesticides in the art. For example, the preparation method can refer to patent application CN118120757A.

[0083] Application

[0084] The present invention provides the application of the micro - mixing channel and the microfluidic chip of the present invention in the preparation of nano - pesticides. In some embodiments, the nano - pesticides are selected from one or more of lambda - cyhalothrin nano - pesticides, emamectin benzoate nano - pesticides, spinosad nano - pesticides, chlorantraniliprole nano - pesticides, imidacloprid nano - pesticides, tebuconazole nano - pesticides, and pyraclostrobin nano - pesticides, and preferably one or two of lambda - cyhalothrin nano - pesticides and emamectin benzoate nano - pesticides.

[0085] The particle size of the nano-pesticide prepared using the micro-mixing channel or the microfluidic chip of the present invention can be below 250 nm, preferably below 200 nm, such as 1 - 200 nm, 20 - 180 nm, 50 - 150 nm. Compared with traditional pesticides, the nano-pesticide prepared using the micro-mixing channel and / or microfluidic chip of the present invention has a smaller particle size and can obtain a larger specific surface area after being sprayed on the leaf surface.

[0086] The polydispersity index of the nano-pesticide prepared using the micro-mixing channel or the microfluidic chip of the present invention is less than 0.2, indicating that the nano-pesticide prepared using the micro-mixing channel and / or microfluidic chip of the present invention is well-dispersed and there is no agglomeration phenomenon in the solution.

[0087] The present invention has the following beneficial effects:

[0088] 1. The present invention combines two structural designs of a contraction-expansion mixing chamber and a jujube pit-shaped baffle. The structure of the contraction-expansion mixing chamber realizes enhanced mixing by changing the cross-sectional area of the channel, and the structure of the jujube pit-shaped baffle divides the main flow into two sub-flows through splitting and recombination and then recombines and collides to generate chaotic flow, significantly enhancing the mixing effect.

[0089] 2. The micro-mixing channel and microfluidic chip of the present invention have strong scalability. The jujube pit-shaped baffle structure in the micro-mixing channel can be expanded and changed as needed, and the number and spacing of the baffles can be increased, and the shape and size of the baffles can be changed to meet different mixing requirements.

[0090] 3. The micro-mixing channel and microfluidic chip of the present invention can be applied to the efficient preparation of nano-pesticides, which is beneficial to industrial scale-up.

[0091] The following further elaborates the present invention in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. The experimental methods without specific conditions noted in the following embodiments are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer. Unless otherwise specified, percentages and parts are calculated by weight. The methods, reagents and materials used in the embodiments are conventional methods, reagents and materials in the art unless otherwise specified. The raw material compounds in the embodiments can be obtained through commercial channels.

[0092] Example 1 Micro-mixing channel

[0093] As Figure 1 and Figure 3As shown in the figure, the micro-mixing channel for preparing nano-pesticides in this embodiment includes a first feed port 1, a second feed port 2, two inlet channels 3 (a first inlet channel and a second inlet channel), an inlet connection channel 4, five contraction-expansion mixing chambers 5, five jujube-shaped baffles 6, an outlet connection channel 7, and a discharge port 8. The first feed port 1 and the second feed port 2 are respectively connected to the first inlet channel and the second inlet channel. The first inlet channel and the second inlet channel are connected to the head end of the inlet connection channel 4. The tail end of the inlet connection channel 4 is connected to the first contraction-expansion mixing chamber 5. The inner wall of the contraction-expansion mixing chamber 5 is in an arc structure. Each contraction-expansion mixing chamber 5 is provided with one jujube-shaped baffle 6. The contraction-expansion mixing chambers 5 are connected in sequence. The last contraction-expansion mixing chamber 5 is connected to the outlet connection channel 7 and the discharge port 8 in sequence.

[0094] When the fluids to be mixed are difficult to complete rapid mixing, it is necessary to improve the mixing performance of the micromixer. By appropriately increasing the number of micro-mixing units included in the micro-mixing channel of the micromixer, the fluids can be divided and converged multiple times in the micro-mixing channel, thereby improving the fluid mixing efficiency. As Figure 2 shown, a micro-mixing unit consists of a contraction-expansion mixing chamber 5 and a jujube-shaped baffle 6. The number of micro-mixing units in Embodiment 1 is 5.

[0095] In this embodiment, the width of the first feed port 1 is 1 mm, and the depth is 1 mm. The width of the second feed port 2 is 1 mm, and the depth is 1 mm. The width of the inlet channel 3 is 1 mm, the length is 5.6 mm, and the depth is 1 mm. The included angle between the first inlet channel and the second inlet channel is 96°. The width of the inlet connection channel 4 is 1 mm, the length is 1 mm, and the depth is 1 mm.

[0096] In this embodiment, the contraction-expansion mixing chamber 5 has two arc-shaped side walls, an inlet, and an outlet. The fluid flows into the contraction-expansion mixing chamber 5 from the inlet of the contraction-expansion mixing chamber 5 and flows out of the contraction-expansion mixing chamber 5 from the outlet of the contraction-expansion mixing chamber 5. The widths at both ends (the inlet end and the outlet end) of the contraction-expansion mixing chamber 5 are smaller than the width a of the middle structure. The width a of the middle structure of the contraction-expansion mixing chamber 5 is 2 mm, the length b is 3 mm, and the depth is 1 mm.

[0097] In this embodiment, a jujube-shaped baffle 6 is provided in the contraction-expansion mixing chamber 5. The maximum width d of the jujube-shaped baffle 6 is 0.7 mm, the maximum length c is 1.4 mm, and the depth is 1 mm. The side surface of the jujube-shaped baffle 6 consists of two arc surfaces. The included angle θ between the central axes of the two arc surfaces of the jujube-shaped baffle 6 and the outlet wall surface of the contraction-expansion mixing chamber is 45°.

[0098] In this embodiment, the width of the outlet connecting channel 7 is 1 mm, the length is 2 mm, and the depth is 1 mm. The width of the discharge port 8 is 1 mm, and the depth is 1 mm.

[0099] In specific applications, the two fluids flow in from the first feed port 1 and the second feed port 2 respectively. Since the fluids are in a laminar flow state, the two fluids basically do not mix in the inlet connecting channel 4. Subsequently, the two fluids enter the micro-mixing unit. The structure of the contraction-expansion mixing chamber 5 can squeeze and stretch the fluids, destroying the laminar flow of the fluids. The spindle-shaped baffle 6 causes the fluids to be shunted. Subsequently, the fluids flow through the two side channels and recombine again at the tail of the spindle-shaped baffle 6. By shunting and recombining the fluids multiple times, the fluids can be repeatedly stretched, cut, and stacked, strengthening the mixing of the two-phase fluids. Finally, the fluids flow out of the contraction-expansion mixing chamber 5 and into the outlet connecting channel 7, and the mixing is completed at the discharge port 8.

[0100] The micro-mixing channel of this embodiment has a split structure. The material of the upper cover plate is borosilicate glass. The material of the lower bottom plate is borosilicate glass.

[0101] Micro-mixing channel of Embodiment 2

[0102] The micro-mixing channel for preparing nano-pesticides in this embodiment includes a first feed port 1, a second feed port 2, two inlet channels 3 (the first inlet channel and the second inlet channel), an inlet connecting channel 4, 10 contraction-expansion mixing chambers 5, 10 spindle-shaped baffles 6, an outlet connecting channel 7, and a discharge port 8. The first feed port 1 and the second feed port 2 are respectively connected to the first inlet channel and the second inlet channel. The first inlet channel and the second inlet channel are connected to the head end of the inlet connecting channel 4. The tail end of the inlet connecting channel 4 is connected to the first contraction-expansion mixing chamber 5. The inner wall of the contraction-expansion mixing chamber 5 is in an arc structure. One spindle-shaped baffle 6 is provided in each contraction-expansion mixing chamber 5. The contraction-expansion mixing chambers 5 are connected in sequence. The last contraction-expansion mixing chamber 5 is connected to the outlet connecting channel 7 and the discharge port 8 in sequence.

[0103] When the fluids to be mixed are difficult to complete rapid mixing, it is necessary to improve the mixing performance of the micro-mixer. By appropriately increasing the number of micro-mixing units included in the micro-mixing channel of the micro-mixer, the fluids can be shunted and converged multiple times in the micro-mixing channel, thereby improving the fluid mixing efficiency. As Figure 2 shown, a micro-mixing unit consists of a contraction-expansion mixing chamber 5 and a spindle-shaped baffle 6. The number of micro-mixing units in Embodiment 2 is 10.

[0104] In this embodiment, the width of the first feed inlet 1 is 0.5 mm, and the depth is 0.5 mm. The width of the second feed inlet 2 is 0.5 mm, and the depth is 0.5 mm. The width of the inlet channel 3 is 0.5 mm, the length is 4 mm, and the depth is 0.5 mm. The included angle between the first inlet channel and the second inlet channel is 90°. The width of the inlet connecting channel 4 is 0.5 mm, the length is 1 mm, and the depth is 0.5 mm.

[0105] In this embodiment, the contraction-expansion mixing chamber 5 has two arc-shaped side walls, an inlet and an outlet. The fluid flows into the contraction-expansion mixing chamber 5 from the inlet of the contraction-expansion mixing chamber 5 and flows out of the contraction-expansion mixing chamber 5 from the outlet of the contraction-expansion mixing chamber 5. The widths at both ends (the inlet end and the outlet end) of the contraction-expansion mixing chamber 5 are smaller than the width a of the middle structure. The width a of the middle structure of the contraction-expansion mixing chamber 5 is 1 mm, the length is 2 mm, and the depth is 0.5 mm.

[0106] In this embodiment, a date-pit-shaped baffle 6 is provided in the contraction-expansion mixing chamber 5. The maximum width d of the date-pit-shaped baffle 6 is 0.4 mm, the maximum length c is 0.8 mm, and the depth is 0.5 mm. The side surface of the date-pit-shaped baffle 6 is composed of two arc surfaces. The included angle θ between the central axes of the two arc surfaces of the date-pit-shaped baffle 6 and the outlet wall surface of the contraction-expansion mixing chamber is 45°.

[0107] In this embodiment, the width of the outlet connecting channel 7 is 0.5 mm, the length is 2 mm, and the depth is 0.5 mm. The width of the discharge port 8 is 0.5 mm, and the depth is 0.5 mm.

[0108] In specific applications, the two fluids flow in from the first feed inlet 1 and the second feed inlet 2 respectively. Since the fluids are in a laminar flow state, the two fluids basically do not mix in the inlet connecting channel 4. Subsequently, the two fluids enter the micro-mixing unit. The structure of the contraction-expansion mixing chamber 5 can squeeze and stretch the fluids, destroying the laminar flow of the fluids. The date-pit-shaped baffle 6 causes the fluids to be split, and then the fluids flow through the two side channels and recombine again at the tail of the date-pit-shaped baffle 6. Through multiple split-recombination of the fluids, the fluids can be repeatedly stretched, cut, and stacked, strengthening the mixing of the two-phase fluids. Finally, the fluids flow out of the contraction-expansion mixing chamber 5 and into the outlet connecting channel 7, and the mixing is completed at the discharge port 8.

[0109] The micro-mixing channel of this embodiment has a split structure. The material of the upper cover plate is borosilicate glass. The material of the lower bottom plate is borosilicate glass.

[0110] Micro-mixing channel of Embodiment 3

[0111] The micro - mixing channel for preparing nano - pesticides in this embodiment includes a first feed port 1, a second feed port 2, two inlet channels 3 (the first inlet channel and the second inlet channel), an inlet connection channel 4, 8 contraction - expansion mixing chambers 5, 8 jujube - kernel - shaped baffles 6, an outlet connection channel 7, and a discharge port 8. The first feed port 1 and the second feed port 2 are respectively connected to the first inlet channel and the second inlet channel. The first inlet channel and the second inlet channel are connected to the head end of the inlet connection channel 4. The tail end of the inlet connection channel 4 is connected to the first contraction - expansion mixing chamber 5. The inner wall of the contraction - expansion mixing chamber 5 is of an arc - shaped structure. Each contraction - expansion mixing chamber 5 is provided with 1 jujube - kernel - shaped baffle 6. The contraction - expansion mixing chambers 5 are connected in sequence. The last contraction - expansion mixing chamber 5 is connected to the outlet connection channel 7 and the discharge port 8 in sequence.

[0112] When the fluids to be mixed are difficult to complete rapid mixing, it is necessary to improve the mixing performance of the micromixer. By appropriately increasing the number of micro - mixing units included in the micro - mixing channel of the micromixer, the fluids can be divided and converged multiple times in the micro - mixing channel, thereby improving the fluid mixing efficiency. As Figure 2 shown, a micro - mixing unit consists of a contraction - expansion mixing chamber 5 and a jujube - kernel - shaped baffle 6. The number of micro - mixing units in Embodiment 3 is 8.

[0113] In this embodiment, the width of the first feed port 1 is 2 mm, and the depth is 2 mm. The width of the second feed port 2 is 2 mm, and the depth is 2 mm. The width of the inlet channel 3 is 2 mm, the length is 8 mm, and the depth is 2 mm. The included angle between the first inlet channel and the second inlet channel is 120°. The width of the inlet connection channel 4 is 2 mm, the length is 2 mm, and the depth is 2 mm.

[0114] In this embodiment, the contraction - expansion mixing chamber 5 has two arc - shaped side walls, an inlet, and an outlet. The fluid flows into the contraction - expansion mixing chamber 5 from the inlet of the contraction - expansion mixing chamber 5 and flows out of the contraction - expansion mixing chamber 5 from the outlet of the contraction - expansion mixing chamber 5. The widths at both ends (the inlet end and the outlet end) of the contraction - expansion mixing chamber 5 are smaller than the width a of the middle structure. The width a of the middle structure of the contraction - expansion mixing chamber 5 is 4 mm, the length is 6 mm, and the depth is 2 mm.

[0115] In this embodiment, a jujube - kernel - shaped baffle 6 is provided in the contraction - expansion mixing chamber 5. The maximum width d of the jujube - kernel - shaped baffle 6 is 1 mm, the maximum length c is 2 mm, and the depth is 2 mm. The side surface of the jujube - kernel - shaped baffle 6 consists of two arc surfaces. The included angle θ between the central axes of the two arc surfaces of the jujube - kernel - shaped baffle 6 and the outlet wall surface of the contraction - expansion mixing chamber is 40°.

[0116] In this embodiment, the width of the outlet connection channel 7 is 2 mm, the length is 3 mm, and the depth is 2 mm. The width of the discharge port 8 is 2 mm, and the depth is 2 mm.

[0117] In specific applications, two fluids flow in from the first feed port 1 and the second feed port 2 respectively. Since the fluids are in a laminar flow state, the two fluids basically do not mix in the inlet connection channel 4. Subsequently, the two fluids enter the micro-mixing unit. The structure of the contraction-expansion mixing chamber 5 can squeeze and stretch the fluids, destroying the laminar flow of the fluids. The spindle-shaped baffle 6 causes the fluids to be diverted. Subsequently, the fluids flow through the two side channels and recombine again at the tail of the spindle-shaped baffle 6. Through multiple diverting-recombining of the fluids, the fluids can be repeatedly stretched, cut, and stacked, strengthening the mixing of the two-phase fluids. Finally, the fluids flow out of the contraction-expansion mixing chamber 5 and into the outlet connection channel 7, and the mixing is completed at the discharge port 8.

[0118] The micro-mixing channel of this embodiment has a split structure. The material of the upper cover plate is borosilicate glass. The material of the lower bottom plate is borosilicate glass.

[0119] Microfluidic chip of Embodiment 4

[0120] As Figure 4 and Figure 5 shown, the microfluidic chip for preparing nano-pesticides of this embodiment includes a first feed port 1, a second feed port 2, two inlet channels 3 (the first inlet channel and the second inlet channel), an inlet connection channel 4, 15 contraction-expansion mixing chambers 5, 15 spindle-shaped baffles 6, an outlet connection channel 7, a discharge port 8, and a vortex mixing channel 9. The first feed port 1 and the second feed port 2 are respectively connected to the first inlet channel and the second inlet channel. The first inlet channel and the second inlet channel are connected to the head end of the inlet connection channel 4. The tail end of the inlet connection channel 4 is connected to the contraction-expansion mixing chamber 5. The microfluidic chip of this embodiment includes 3 micro-mixing unit assemblies, and each micro-mixing unit assembly includes 5 contraction-expansion mixing chambers 5. The inner wall of the contraction-expansion mixing chamber 5 has an arc-shaped structure. One spindle-shaped baffle 6 is provided in each contraction-expansion mixing chamber 5. The contraction-expansion mixing chambers 5 in each micro-mixing unit assembly are connected in sequence. Adjacent micro-mixing unit assemblies are connected through the vortex mixing channel 9. Adjacent micro-mixing unit assemblies are arranged in a parallel and circuitous shape, and the head and tail of the latter micro-mixing unit assembly are respectively aligned with the tail and head of the former micro-mixing unit assembly. The last contraction-expansion mixing chamber 5 is connected to the outlet connection channel 7 and the discharge port 8 in sequence.

[0121] When the fluids to be mixed are difficult to achieve rapid mixing, it is necessary to improve the mixing performance of the micromixer. By appropriately increasing the number of micromixing units included in the micromixing channels of the micromixer, the fluids can be divided and converged multiple times in the micromixing channels, thereby improving the fluid mixing efficiency. A micromixing unit consists of a contraction-expansion mixing chamber 5 and a date-pit-shaped baffle 6. As Figure 4 shown, in Embodiment 4, the micromixing units are distributed in multiple rows and in a meandering shape, and adjacent rows are connected by a vortex mixing channel 9.

[0122] In Embodiment 4, the number of rows of micromixing units is 3 rows, and the number of micromixing units in each row is 5.

[0123] In this embodiment, the width of the first feed port 1 is 1 mm, and the depth is 1 mm. The width of the second feed port 2 is 1 mm, and the depth is 1 mm. The width of the inlet channel 3 is 1 mm, the length is 5.6 mm, and the depth is 1 mm. The angle between the first inlet channel and the second inlet channel is 96°. The width of the inlet connecting channel 4 is 1 mm, the length is 1 mm, and the depth is 1 mm.

[0124] In this embodiment, the contraction-expansion mixing chamber 5 has two arc-shaped side walls, one inlet and one outlet. The fluid flows into the contraction-expansion mixing chamber 5 from the inlet of the contraction-expansion mixing chamber 5 and flows out of the contraction-expansion mixing chamber 5 from the outlet of the contraction-expansion mixing chamber 5. The widths at both ends (the inlet end and the outlet end) of the contraction-expansion mixing chamber 5 are smaller than the width a of the middle structure. The width a of the middle structure of the contraction-expansion mixing chamber 5 is 2 mm, the length is 3 mm, and the depth is 1 mm.

[0125] In this embodiment, a date-pit-shaped baffle 6 is provided in the contraction-expansion mixing chamber 5. The maximum width d of the date-pit-shaped baffle 6 is 0.7 mm, the maximum length c is 1.4 mm, and the depth is 1 mm. The side surface of the date-pit-shaped baffle 6 consists of two arc surfaces. The angle θ between the central axes of the two arc surfaces of the date-pit-shaped baffle 6 and the outlet wall surface of the contraction-expansion mixing chamber is 45°.

[0126] In this embodiment, the width of the vortex mixing channel 9 is 1 mm, the length is 7 mm, and the depth is 1 mm. The vortex mixing channel 9 is arc-shaped. The angle between the inlet and the outlet of the vortex mixing channel 9 is 180°.

[0127] In this embodiment, the width of the outlet connecting channel 7 is 1 mm, the length is 2 mm, and the depth is 1 mm. The width of the discharge port 8 is 1 mm, and the depth is 1 mm.

[0128] In specific applications, the two fluids flow in from the first feed port 1 and the second feed port 2 respectively. Since the fluids are in a laminar flow state, the two fluids basically do not mix in the inlet communication channel 4. Subsequently, the two fluids enter the micro-mixing unit. The structure of the contraction-expansion mixing chamber 5 can squeeze and stretch the fluids, destroying the laminar flow of the fluids. The spindle-shaped baffle 6 causes the fluids to be split, and then the fluids flow through the two side channels and recombine again at the tail of the spindle-shaped baffle 6. By splitting and recombining the fluids multiple times, the fluids can be repeatedly stretched, cut, and stacked, strengthening the mixing of the two-phase fluids. Finally, the fluids flow out of the contraction-expansion mixing chamber 5 and into the outlet communication channel 7, and the mixing is completed at the discharge port 8.

[0129] The physical diagram of the microfluidic chip of this embodiment is as Figure 7 shown.

[0130] The microfluidic chip of this embodiment has a split structure. The material of the upper cover plate is borosilicate glass. The material of the lower bottom plate is borosilicate glass.

[0131] Simulation of the microfluidic chip in Example 5

[0132] The microfluidic chip of Example 4 is simulated using COMSOL software. The three-dimensional model of the microfluidic chip is mixed and simulated in a steady state using two physical fields: laminar flow and dilute species transport. The material selected in the model is water; the concentrations of the first feed port 1 and the second feed port 2 are 0 and 1 mol / m 3 respectively; at the inlet of the microfluidic chip, a velocity inlet boundary condition is adopted; at the outlet of the microfluidic chip, a pressure outlet boundary condition is adopted; except for the inlet and outlet, all wall boundary conditions are no-slip; the fluid density, dynamic viscosity, and diffusion coefficient used in this simulation are 1000 kg / m 3 , 0.001 Pa·s, and 1×10 -11 m 2 / s respectively. The mixing degree of the microfluidic chip is usually represented by the mass fraction of the fluid components. The mass fraction distribution diagram of the fluid in the microfluidic chip is as Figure 6 shown. It can be seen from Figure 6 that the two fluids are completely mixed and uniform at the outlet of the microfluidic chip, indicating that the microfluidic chip has excellent mixing effects.

[0133] Preparation of lambda-cyhalothrin nano-pesticide in Example 6

[0134] The microfluidic chip of Example 4 was used to prepare highly efficient lambda-cyhalothrin nano-pesticide. One syringe pump was connected to the first feed port 1 to pump the organic phase, and another syringe pump was connected to the second feed port 2 to pump the aqueous phase. The organic phase and the aqueous phase were rapidly mixed in the microfluidic chip and then flowed out from the outlet 8 and were sampled by a centrifuge tube. The organic phase was an ethanol aqueous solution (volume ratio of ethanol to water was 8:2) dissolving a certain mass fraction of the pesticide lambda-cyhalothrin (mass fraction of lambda-cyhalothrin in the organic phase was 1% (w / v)) and the carrier zein (mass fraction of zein in the organic phase was 0.5% (w / v)), and the aqueous phase was ultrapure water. The organic phase and the aqueous phase with a volume ratio of 1:4 were rapidly mixed through the microfluidic chip at a total flow rate of 28 mL / min to obtain the lambda-cyhalothrin nano-pesticide. The DLS characterization analysis was carried out on the lambda-cyhalothrin nano-pesticide prepared in this example. The particle size of the lambda-cyhalothrin nano-pesticide was about 137.2 ± 0.1 nm, and the polydispersity index was 0.07 ± 0.01. The transmission electron microscope image was as shown in Figure 8 shown.

[0135] Preparation of emamectin benzoate nano-pesticide in Example 7

[0136] The microfluidic chip of Example 4 was used to prepare emamectin benzoate nano-pesticide. One syringe pump was connected to the first feed port 1 to pump the organic phase, and another syringe pump was connected to the second feed port 2 to pump the aqueous phase. The organic phase and the aqueous phase were rapidly mixed in the microfluidic chip and then flowed out from the outlet 8 and were sampled by a centrifuge tube. The organic phase was an ethanol aqueous solution (volume ratio of ethanol to water was 8:2) dissolving a certain mass fraction of the pesticide emamectin benzoate (mass fraction of emamectin benzoate in the organic phase was 2% (w / v)) and the carrier zein (mass fraction of zein in the organic phase was 2% (w / v)), and the aqueous phase was ultrapure water. The organic phase and the aqueous phase with a volume ratio of 1:4 were rapidly mixed through the microfluidic chip at a total flow rate of 81 mL / min to obtain the emamectin benzoate nano-pesticide. The DLS characterization analysis was carried out on the emamectin benzoate nano-pesticide prepared in this example. The particle size of the emamectin benzoate nano-pesticide was about 72.59 ± 1.24 nm, and the polydispersity index was 0.17 ± 0.01.

[0137] It should be noted that the above-described embodiments should be understood as illustrative and not limiting the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims. For those skilled in the art, without departing from the essence and scope of the present invention, some non-essential improvements and adjustments made to the present invention still fall within the scope of protection of the present invention.

Claims

1. A micro-mixing channel, characterized in that: The micro-mixing channel comprises at least two feed ports, at least two inlet channels connected to the feed ports, an inlet communication channel connected to the other end of all the inlet channels away from the feed ports, at least two micro-mixing units connected to the inlet communication channel, an outlet communication channel connected to the last micro-mixing unit, and an outlet connected to the outlet communication channel; The micro-mixing unit is a contraction-expansion mixing chamber with a jujube-shaped baffle disposed inside, the contraction-expansion mixing chamber includes an inlet of the contraction-expansion mixing chamber, a middle structure with a jujube-shaped baffle disposed inside, and an outlet of the contraction-expansion mixing chamber, the previous micro-mixing unit is connected to the inlet of the contraction-expansion mixing chamber of the next micro-mixing unit through the outlet of its contraction-expansion mixing chamber, the inlet communication channel is connected to the inlet of the contraction-expansion mixing chamber of the first micro-mixing unit, and the outlet communication channel is connected to the outlet of the contraction-expansion mixing chamber of the last micro-mixing unit.

2. The micro-mixing channel according to claim 1, characterized in that: The micro-mixing channel has one or more of the following features: The feed opening has a width of 0.1-2 mm and a depth of 0.1-2 mm; The inlet channel has a width of 0.1-2 mm, a depth of 0.1-2 mm, and a length of 2-12 mm; The inlet communication channel has a width of 0.1-2 mm, a depth of 0.1-2 mm, and a length of 0.5-10 mm; The middle structure of the contraction-expansion mixing chamber has a width of 1-5 mm, a depth of 0.1-2 mm, and a length of 2-8 mm; The maximum width of the jujube-shaped baffle is 0.1-2mm, the depth is 0.1-2mm, and the maximum length is 0.2-4mm; The outlet communication channel has a width of 0.1-2 mm, a depth of 0.1-2 mm, and a length of 0.5-10 mm; The width of the discharge port is 0.1-2 mm, and the depth is 0.1-2 mm; Preferably, the micro-mixing channel comprises two feed ports and two inlet channels respectively connected to the two feed ports; preferably, the angle between the two inlet channels is 45°-120°; The micro-mixing channel includes 2-15 micro-mixing units.

3. The micro-mixing channel according to claim 1, characterized in that: The micro-mixing channel has one or more of the following features: The middle structure of the contraction-expansion mixing chamber has two arc-shaped side walls; The inlet of the contraction-expansion mixing chamber and the outlet of the contraction-expansion mixing chamber each have two parallel walls, and the walls are connected to the arc-shaped side walls of the middle structure; The width of the middle structure of the contraction-expansion mixing chamber is greater than the width of the inlet and outlet of the contraction-expansion mixing chamber; The jujube-shaped baffle is composed of two curved surfaces; Preferably, the angle between the central axis of the two curved surfaces of the jujube-shaped baffle and the outlet wall surface of the contraction-expansion mixing chamber is 30°-60°.

4. A microfluidic chip, characterized in that: The microfluidic chip comprises at least two feed ports, at least two inlet channels connected to the feed ports, an inlet communication channel to which all the inlet channels lead at the other end away from the feed ports, at least two micro-mixing unit assemblies connected to the inlet communication channel, a vortex mixing channel connecting two adjacent micro-mixing unit assemblies, an outlet communication channel connected to the last micro-mixing unit assembly, and an outlet connected to the outlet communication channel; The micro-mixing unit assembly includes at least two micro-mixing units, each of which is a contraction-expansion mixing chamber with a jujube-shaped baffle disposed therein, the contraction-expansion mixing chamber including an inlet of the contraction-expansion mixing chamber, a middle structure with a jujube-shaped baffle disposed therein, and an outlet of the contraction-expansion mixing chamber, and the outlet of the contraction-expansion mixing chamber of the upper micro-mixing unit is connected to the inlet of the contraction-expansion mixing chamber of the lower micro-mixing unit through the outlet of the contraction-expansion mixing chamber thereof; The inlet of the contraction-expansion mixing chamber of the first micro-mixing unit in the first micro-mixing unit assembly is communicated with the inlet communication channel, and the outlet of the contraction-expansion mixing chamber of the last micro-mixing unit in the last micro-mixing unit assembly is communicated with the outlet communication channel.

5. The microfluidic chip according to claim 4, characterized in that: The microfluidic chip has one or more of the following features: The feed opening has a width of 0.1-2 mm and a depth of 0.1-2 mm; The inlet channel has a width of 0.1-2 mm, a depth of 0.1-2 mm, and a length of 2-12 mm; The inlet communication channel has a width of 0.1-2 mm, a depth of 0.1-2 mm, and a length of 0.5-10 mm; The middle structure of the contraction-expansion mixing chamber has a width of 1-5 mm, a depth of 0.1-2 mm, and a length of 2-8 mm; The maximum width of the jujube-shaped baffle is 0.1-2mm, the depth is 0.1-2mm, and the maximum length is 0.2-4mm; The vortex mixing channel has a width of 0.1-2 mm, a depth of 0.1-2 mm, and a length of 4-20 mm; The outlet communication channel has a width of 0.1-2 mm, a depth of 0.1-2 mm, and a length of 0.5-10 mm; The width of the discharge port is 0.1-2 mm, and the depth is 0.1-2 mm; Preferably, the microfluidic chip comprises two feed ports, and two inlet channels respectively connected to the two feed ports; preferably, the angle between the two inlet channels is 45°-120°; Each of the micro-mixing unit assemblies includes 2-15 micro-mixing units; The microfluidic chip includes 2-10 micro-mixing unit assemblies.

6. The microfluidic chip according to claim 4, characterized in that: The microfluidic chip has one or more of the following features: The middle structure of the contraction-expansion mixing chamber has two arc-shaped side walls; The inlet of the contraction-expansion mixing chamber and the outlet of the contraction-expansion mixing chamber each have two parallel walls, and the walls are connected to the arc-shaped side walls of the middle structure; The width of the middle structure of the contraction-expansion mixing chamber is greater than the width of the inlet and outlet of the contraction-expansion mixing chamber; The jujube-shaped baffle is composed of two curved surfaces; Preferably, the angle between the central axis of the two curved surfaces of the jujube-shaped baffle and the outlet wall surface of the contraction-expansion mixing chamber is 30°-60°.

7. The microfluidic chip according to claim 4, characterized in that: The micro-mixing unit assemblies are arranged in parallel and in a circuitous manner, and the head and tail of a subsequent micro-mixing unit assembly are respectively aligned with the tail and head of a previous micro-mixing unit assembly; and / or the vortex mixing flow channel is in an arc shape.

8. A method for preparing the micro-mixing channel according to any one of claims 1 to 3 and the microfluidic chip according to any one of claims 4 to 7, characterized in that: The method comprises a process selected from the group consisting of etching, MEMS manufacturing process, 3D printing, machining and ultrafast laser processing.

9. The micro-mixing channel according to any one of claims 1 to 3 and the microfluidic chip according to any one of claims 4 to 7, characterized in that: The micro-mixing channel and / or the microfluidic chip have an integrated structure; or The micro-mixing channel and / or the microfluidic chip has a split structure, which includes an upper cover plate and a lower bottom plate, and the structure for forming the outer wall of each channel and chamber is arranged on the lower bottom plate, and the upper cover plate and the lower bottom plate are covered to form each channel and chamber; Preferably, the materials of the integrated structure, the upper cover plate and the lower base plate are independently selected from one or more of borosilicate glass, quartz glass, acrylonitrile-butadiene-styrene copolymer, polyamide, polybutylene terephthalate, polyether and polymethyl methacrylate.

10. Use of the micro-mixing channel according to any one of claims 1 to 3 and the microfluidic chip according to any one of claims 4 to 7 in the preparation of nanopesticides; preferably, the nanopesticide is selected from one or more of high-efficiency chlorflucythrinate nanopesticide, avermectin benzoate nanopesticide, spinosad nanopesticide, chlorantraniliprole nanopesticide, imidacloprid nanopesticide, tebuconazole nanopesticide and pyraclostrobin nanopesticide.

Images