Multi-channel micro-fluid emulsification membrane for large-scale manufacturing of monodisperse emulsion droplets, and use of multi-channel micro-fluid emulsification membrane

Abstract

The present invention relates to the technical field of membrane emulsification, and in particular to a multi-channel micro-fluid emulsification membrane for large-scale manufacturing of monodisperse emulsion droplets, and a use of the multi-channel micro-fluid emulsification membrane. The emulsification membrane comprises at least one through hole, wherein the cross section of the through hole is rectangular, the length of the short side of the cross section of the through hole is 0.005-1.5 mm, and a side length ratio of the short side to the long side is 1:2-1:10. According to the emulsification membrane, membrane emulsification technology is combined with micro-fluidic droplet technology for use, and by means of matrix arrangement and free shaping, low-energy-consumption, high-flux and automatic production of various micro-emulsions having unique manufacturing requirements and small- and narrow-particle-size distribution is satisfied; and on the basis of the micro-fluidic droplet technology, the through hole structure of the present invention can realize high-precision emulsification at an emulsion level comparable to that of traditional dilute solution emulsification under an emulsification condition without the help of external force.

Description

A multi-channel microfluidic emulsification membrane for large-scale production of monodisperse emulsion droplets and its application Technical Field

[0001] The present invention belongs to the field of membrane emulsification technology, specifically a multi-channel microfluidic emulsification membrane and an emulsification device designed based on microfluidic principles, as well as an application method for using the device to mass-produce monodisperse emulsion droplets of uniform size. Background Art

[0002] Emulsion technology is widely used to prepare microdroplets for encapsulating bioactive substances (such as bioactive macromolecule drugs or living cells). It has extensive applications in the chemical, pharmaceutical, and biochemical industries. Highly uniform microdroplets can also be used as standard droplets for various high-precision biochemical and immunological experiments, such as tissue engineering and single-cell and single-molecule research. Common emulsification methods include membrane emulsification, spraying, stirring emulsification, and the emerging microfluidics method. Among them, membrane emulsification technology, characterized by low energy consumption, mild conditions, and high production throughput, has been widely used in the preparation of various cosmetics, food, and drug carriers. Conventional membrane emulsification technology typically utilizes the flow of a dispersed phase through a membrane structure toward a continuous phase. The dispersed phase forms and grows in the membrane pores. Under the combined effects of surface tension, transmembrane pressure, continuous phase drag, and buoyancy, it leaves the membrane surface to form droplets. Because conventional membrane emulsification technology relies on the passive effects of liquid phase forces to achieve emulsification, the droplet size distribution is relatively wide, making it unsuitable for large-scale production of high-precision emulsion products such as drugs and cell carriers. At the same time, due to the limitations of the passive emulsification principle, it will be more difficult to achieve high-throughput production of small-particle emulsions when emulsifying high-viscosity dispersed phases, and therefore it will be even more difficult to apply to the production of viscous microgels such as hydrogels.

[0003] In contrast, microfluidics can produce more uniform droplet emulsions and has therefore become widely used in various biochemical studies. This method typically utilizes two immiscible liquid phases to form a monodisperse emulsion of controlled size under highly controlled microscopic forces. Common microfluidic techniques for producing microdroplets include passive emulsification methods that utilize various structural controls and active emulsification methods that introduce additional forces from an external source. However, these conventional microfluidic droplet technologies have the following problems: 1) Highly precise microfluidic chips are usually required to complete droplet production, and the chip equipment cost is high (CN 105641743A, CN104511320A); 2) The droplet production flux of microfluidic droplet production technologies based on various microchannels is low (<1L / h), and it usually takes a long time to complete the production of a certain dose of uniform microemulsion droplets (CN112275336A, CN110038656A); 3) The emulsion formation process is highly dependent on the flow rate of each liquid phase, and high real-time control requirements are placed on each liquid phase in the production process, making it difficult to achieve large-scale application in actual applications (CN107930542A, CN107511189A).

[0004] Therefore, how to achieve high-throughput preparation of high-viscosity dispersed phases remains a key issue in breaking through the application of microparticles loaded with bioactive substances in clinical or other fields.

[0005] Summary of the Invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a multi-channel microfluidic emulsification membrane design based on microfluidics and an application method thereof for high-throughput mass production of monodisperse emulsion droplets.

[0007] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0008] On one hand, the present invention provides a multi-channel microfluidic emulsification membrane for manufacturing emulsified droplets, comprising at least one through hole, wherein the through hole has a rectangular cross-section, the short side length of the cross section is 0.005-1.5 mm, and the length ratio of the short side to the long side is 1:2-1:10.

[0009] In the above technical solution, further, the through holes are arranged in a rectangular array, the spacing between the through holes in the first direction is 0.2-20 times the length of the long side, and the spacing between the through holes in the second direction is 0.4-20 times the length of the long side.

[0010] In the above technical solution, further, the thickness of the multi-channel microfluidic emulsification membrane is 0.01 mm-10 mm, and the depth of the through hole is more than 1 times the length of the long side.

[0011] In the above technical solution, further, the surface of the multi-channel microfluidic emulsification membrane is strongly hydrophobic or strongly hydrophilic.

[0012] In the above technical solution, further, the multi-channel microfluidic emulsification membrane is a tubular, sheet-shaped, or spherical membrane.

[0013] In the above technical solution, further, the multi-channel microfluidic emulsification membrane is made of one or more combinations of glass, silicon, metal, ceramic, organic polymer, or organic-inorganic composite materials, and the through holes are processed by laser, drilling, etching, 3D printing or integral molding.

[0014] In the above technical solution, further, the through-hole array is located in the center of the plane of the multi-channel microfluidic emulsification membrane, and a blank area is left at the edge of the membrane without through-holes, wherein the straight-line distance between the through-holes outside the through-hole array and the edge of the membrane is greater than 2 times the length of the long side.

[0015] The second aspect of the present invention provides an emulsification device, comprising the aforementioned multi-channel microfluidic emulsification membrane, wherein the multi-channel microfluidic emulsification membrane is encapsulated in a liquid phase chamber to seal the liquid phase chamber, and the emulsification device is provided with an input hole for introducing a dispersed phase into the liquid phase chamber; preferably, when there are multiple liquid phase chambers, the number of input holes is the same as the number of liquid phase chambers, and corresponds one to one; the multiple liquid phase chambers are arranged in layers, and the liquid phase chambers that are not directly connected to the multi-channel microfluidic emulsification membrane are connected to the multi-channel microfluidic emulsification membrane through input channels, and the outlet of the input channel is lower than the upper surface of the through-hole of the multi-channel microfluidic emulsification membrane, the number of input channels is consistent with the number of through-holes of the multi-channel microfluidic emulsification membrane, and the input channels correspond one to one with the through-holes of the multi-channel microfluidic emulsification membrane.

[0016] In the above technical solution, further, the multi-channel microfluidic emulsion membrane is packaged and sealed by one or more methods selected from the group consisting of hot pressing, gluing, laser welding, ultrasonic welding, bolting, anodic bonding, and plasma bonding.

[0017] A third aspect of the present invention provides a membrane emulsification method, comprising using the emulsification device according to claim 7, comprising the following steps:

[0018] (1) placing an emulsification device in a continuous phase emulsion, with the dispersed phase and the continuous phase placed on both sides of a multi-channel microfluidic emulsification membrane;

[0019] (2) The dispersed phase is introduced into the liquid phase chamber, and the dispersed phase enters the continuous phase through the through-holes of the multi-channel microfluidic emulsification membrane, and continuous emulsification is completed under the induction of emulsification control factors; preferably, the emulsification control factors are selected from one or more of buoyancy, gravity, centrifugal force, electric field force, hydraulic shear force, magnetic force, temperature, interfacial tension, ultraviolet light irradiation, infrared light irradiation, and laser induction.

[0020] In the above technical solution, further, when the buoyancy factor is selected as the emulsification control factor, the density difference between the continuous phase and the dispersed phase is required to be greater than 0.2 g / ml, preferably, the density difference range is 0.3-0.6 g / ml; when preparing the emulsion, if the density of the dispersed phase is greater than that of the continuous phase, the multi-channel microfluidic emulsification membrane is placed horizontally, with the dispersed phase placed above the membrane and the continuous phase placed below the membrane; otherwise, the positions of the dispersed phase and the continuous phase are swapped;

[0021] When the emulsification control factor is the gravity factor, the continuous phase is the gas phase; when preparing the emulsion, the multi-channel microfluidic emulsification membrane is placed horizontally, the dispersed phase is placed above the membrane, and the continuous phase is placed below the membrane;

[0022] When the centrifugal force factor is selected as the emulsification control factor, a density difference is required between the continuous phase and the dispersed phase, and the density of the dispersed phase must be greater than that of the continuous phase. Preferably, the density difference ranges from 0.1 to 0.4 g / ml. When preparing the emulsion, an additional centrifugal device is required. The multi-channel microfluidic emulsification membrane is placed perpendicular to the centrifugal radius, the dispersed phase is placed close to the centrifugal center, and the continuous phase is placed away from the centrifugal center.

[0023] When the emulsification control factor is an electric field force factor, the surface of the multi-channel microfluidic emulsification membrane needs to be gold-sprayed, or a metal-based multi-channel microfluidic emulsification membrane is used, and insulating materials are continuously selected accordingly; when preparing the emulsion, an additional electrostatic generation device is introduced, and a flat electrode with an area larger than the multi-channel microfluidic emulsification membrane is connected to the electrostatic generation device and placed horizontally with the multi-channel microfluidic emulsification membrane, and the multi-channel microfluidic emulsification membrane is grounded;

[0024] When the emulsification control factor is a magnetic factor, a magnetic material needs to be introduced into the continuous phase; when the emulsion is prepared, a parallel magnetic field perpendicular to the multi-channel microfluidic emulsification membrane is additionally introduced.

[0025] A fourth aspect of the present invention provides the use of the aforementioned multi-channel microfluidic emulsification membrane or the aforementioned emulsification device in large-scale production of monodisperse emulsion droplets.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1) The emulsification membrane of the present invention has specific through-holes, which realizes the combination of membrane emulsification technology and microfluidic droplet technology. Through the independent arrangement of through-holes, random arrangement or matrix arrangement, the emulsification membrane meets the low-energy consumption, high-throughput, and automated production of various small-particle and narrow-size distribution microemulsions with unique manufacturing requirements under conditions of extremely high space utilization (for example, using an 8 cm × 8 cm emulsification membrane, emulsion droplets with a particle size of 114.3 ± 0.6 μm can be prepared at a throughput of 71.2 L / h);

[0028] 2) Based on microfluidic droplet technology, the through-hole structure of the present invention can achieve high-precision emulsification at an emulsion level comparable to traditional dilute solution emulsification without the aid of external force, including but not limited to high-viscosity polymer prepolymer solutions such as alginate and sodium carboxymethyl cellulose, to prepare high-viscosity hydrogel emulsion droplets with small particle size and narrow particle size distribution; the emulsion droplet products obtained by the present invention have a particle size range of 0.01-10 mm and a particle size distribution of less than 5%.

[0029] 3) Different from the passive emulsification scheme in traditional microfluidic droplet technology, the present invention significantly reduces the control parameters required for droplet production. Based on control factors such as buoyancy, gravity, centrifugal force, electric field force, and magnetic force, the preparation of monodisperse emulsions can be achieved without precisely limiting the dispersed phase input flow rate.

[0030] 4) Compared with the traditional high-precision membrane emulsification process for producing microspheres and microdroplets (CN 1939281A, CN105246580A), the multi-channel microfluidic emulsification membrane of the present invention is based on the microfluidic control mechanism of microfluidic droplet technology, which significantly reduces the supporting emulsification factors (shear equipment, stirring equipment, tangential flow rate), simplifies the production process, and reduces equipment construction costs;

[0031] 5) When the multi-channel microfluidic emulsification membrane of the present invention is used to continuously produce emulsion droplets, the continuous phase and the dispersed phase exhibit a spontaneous separation effect under different production environments. Therefore, after emulsification is completed, the dispersed phase emulsion droplets can automatically separate from the continuous phase, completing the initial separation step, eliminating separation steps such as centrifugation and drying in traditional emulsification processes.

[0032] 6) The independent arrangement of the through-holes of the emulsifying membrane of the present invention can avoid the possibility of collision and fusion between multiple droplets when droplets are formed, so that each through-hole emulsifies relatively independently, avoiding contamination between droplets and uneven product size. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram of the planar structure of a multi-channel microfluidic emulsification membrane;

[0034] Figure 2 Schematic diagram of the three-dimensional structure of a multi-channel microfluidic emulsification membrane;

[0035] Figure 3 is a three-dimensional schematic diagram of the emulsification device, wherein 1 is the input hole, 2 is the liquid phase chamber, 3 is the multi-channel microfluidic emulsification membrane, and 4 is the input channel;

[0036] Figure 4: Micrograph of a multi-channel microfluidic emulsification membrane;

[0037] FIG5 shows the droplet formation on the surface of the multi-channel microfluidic emulsion membrane containing 30 through-holes in Example 1;

[0038] FIG6 is a micrograph of droplet formation in a single membrane pore when preparing a water-in-oil emulsion using a multi-channel microfluidic emulsification membrane according to Example 1;

[0039] FIG7 is a micrograph of a water-in-oil emulsion product prepared by a multi-channel microfluidic emulsification membrane according to Example 1;

[0040] FIG8 is a micrograph of droplet formation in a single membrane pore when preparing water-in-oil emulsions using multi-channel microfluidic emulsification membranes with different pore sizes according to Example 2;

[0041] FIG9 is a diagram showing the particle size distribution of water-in-oil emulsion droplets prepared by emulsification membranes with different pore sizes in Example 2;

[0042] FIG10 is a product photograph of the PEGDA600 gel obtained by preparing the multi-channel microfluidic emulsification membrane in Example 3 for 1 minute, wherein the upper white emulsion contains the obtained gel product;

[0043] FIG11 is a diagram showing the size distribution of different gel products prepared by the multi-channel microfluidic emulsification membrane in Example 3;

[0044] Figure 12 is a schematic diagram of the three-dimensional structure of a multi-channel microfluidic emulsification membrane, where X is the pore spacing in the first direction, Y is the pore spacing in the second direction, L is the length of the long side of the pore, h is the length of the short side, and H is the through-pore depth (i.e., membrane thickness);

[0045] Figure 13 shows the droplet formation on the surface of the multi-channel microfluidic emulsion membrane containing 300 through-holes in Example 1

[0046] FIG14 is a schematic diagram of a multilayer emulsification device for producing yin-yang structured microgels;

[0047] FIG15 is a schematic diagram of a multilayer emulsification device for producing core-shell microgels;

[0048] FIG16 is a cell-laden microgel having a yin-yang structure obtained by preparing the membrane in Example 8;

[0049] FIG17 is a dual fluorescent microgel with a yin-yang structure prepared in Example 4;

[0050] FIG18 is a cell-laden microgel prepared in Example 7, wherein the green bright spots are rat mesenchymal stem cells transfected with green fluorescent protein;

[0051] FIG19 is a diagram of the E. coli-loaded microgel prepared in Example 6;

[0052] FIG20 is a magnetic particle-carrying microgel prepared in Example 9;

[0053] FIG21 is a PMMA microgel prepared in Example 10;

[0054] FIG22 is a core-shell structure microgel prepared in Example 5;

[0055] FIG23 is a polyethylene glycol dimethacrylate microgel prepared in Example 11;

[0056] Figure 24 is a schematic diagram of the preparation apparatus of Example 10;

[0057] Figure 25 is a schematic diagram of the preparation apparatus of Example 11;

[0058] FIG26 is an electron micrograph of the planar structure of different multi-channel microfluidic emulsification membranes used in Example 12;

[0059] FIG. 27 is a diagram showing the actual production effect of the multi-channel microfluidic emulsification membrane of structure i-iii shown in FIG. 26 used in Example 12. FIG. DETAILED DESCRIPTION

[0060] The present invention will be further described below with reference to specific examples, but the present invention is not limited thereto in any way.

[0061] The multi-channel microfluidic emulsification membrane disclosed in the embodiments of the present invention combines the membrane emulsification concept with microfluidic droplet technology. Taking the preparation of hydrogel-based polymers as an example, it can continuously and stably prepare a variety of hydrogel emulsion droplets, and can automatically complete the separation of the continuous phase and the dispersed phase by using the density difference between the liquid phases. The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0062] The multi-channel microfluidic emulsification membrane disclosed in the present invention, as shown in Figures 1 and 2, is provided with a plurality of through-holes on its substrate to form a rectangular array. The cross-section of the through-hole is rectangular, the length h of the short side of the cross section is 0.005-1.5mm, the length ratio of the short side to the long side is 1:2-1:10, and the through-holes are arranged in a rectangular array. The spacing X between the through-holes in the first direction is 0.2-20 times the length L of the long side, and the spacing Y between the through-holes in the second direction is 0.4-20 times the length L of the long side (Figure 12). The thickness of the multi-channel microfluidic emulsification membrane is 0.01mm-10mm, and the depth H of the through-hole is more than 1 times the length of the long side. Figure 4 is a micrograph of the multi-channel microfluidic emulsification membrane.

[0063] As shown in Figure 3, the emulsification device includes a multi-channel microfluidic emulsification membrane 3 and a liquid phase chamber 2. The multi-channel microfluidic emulsification membrane is fixedly encapsulated in the liquid phase chamber by a clamp or other encapsulation method, so that the liquid phase chamber is sealed and the liquid phase chamber side of the multi-channel microfluidic emulsification membrane is completely isolated from the other side of the multi-channel microfluidic emulsification membrane, except for the through-holes of the multi-channel microfluidic emulsification membrane. The emulsification device also includes an input hole 1, which is connected to the input pipe of the dispersed phase and is used to introduce the dispersed phase into the liquid phase chamber. The emulsification device is placed as a whole in a continuous phase reservoir, and the multi-channel microfluidic emulsification membrane and the liquid phase chamber are both immersed below the continuous phase liquid surface. As shown in Figure 14 or 15, the emulsification device includes two liquid phase chambers, which are arranged in layers. The multi-channel microfluidic emulsification membrane is fixedly encapsulated in the upper liquid phase chamber by a clamp or other encapsulation method, so that the upper and lower liquid phase chambers are sealed, and one side of the liquid phase chamber of the multi-channel microfluidic emulsification membrane is completely isolated from the other side of the multi-channel microfluidic emulsification membrane. Each layer of the liquid phase chamber is provided with an input hole 1, and each input hole is connected to an input pipe of a dispersed phase to introduce different dispersed phases into the two liquid phase chambers. The liquid phase chamber that is not directly connected to the multi-channel microfluidic emulsification membrane is connected to the multi-channel microfluidic emulsification membrane through the input channel 4. The outlet of the input channel 4 is lower than the upper surface of the through-hole of the multi-channel microfluidic emulsification membrane. The number of input channels is consistent with the number of through-holes of the multi-channel microfluidic emulsification membrane, and the input channels correspond one-to-one to the through-holes of the multi-channel microfluidic emulsification membrane.

[0064] For example, consider a case where the density of the continuous phase is greater than that of the dispersed phase. The dispersed phase is injected into the liquid phase chamber, and any residual air within the chamber is evacuated. The dispersed phase is then injected uniformly at a set flow rate. As it passes through the through-pores of the multichannel microfluidic emulsification membrane, it propels itself at a constant curvature interface within the pores. Upon reaching the pore outlet, the dispersed phase drag and interfacial tension between the two phases drive the dispersed phase within the membrane pores to rapidly enter the droplets at the outlet, rapidly reducing the curvature of the interphase interface within the membrane pores and completing the droplet detachment step. After detaching from the membrane surface, the droplets, driven by the density difference between the two phases, accumulate in the upper layer of the continuous phase and remain stable under the action of surfactants. Collecting the surface-enriched emulsion droplets yields the microemulsion product.

[0065] The multi-channel microfluidic emulsification membrane can be made of one or more combinations of glass, silicon, metal, organic polymer, or organic-inorganic composite materials. The processing method can be laser, drilling, etching, 3D printing (Figure 4) or overall molding, and hydrophilic or hydrophobic treatment can be performed according to the target emulsion properties.

[0066] It can be seen that the multi-channel microfluidic emulsification membrane based on microfluidic droplet technology disclosed in the present invention and its application have simple supporting equipment and concise production process, and can adapt to the preparation of different types of hydrogel microemulsions; use microfluidic droplet technology to ensure the continuous formation of emulsion droplets; and use the physical properties of the dispersed phase itself to complete the separation of the emulsion. Compared with traditional microfluidic droplet technology, the present invention combines the membrane emulsification concept and, through the design of a multi-channel microfluidic emulsification membrane, greatly shortens the production time of microgel emulsions while maintaining the microgel particle size distribution, simplifies the production process, and significantly increases the production throughput, providing an efficient platform for the production of polymer microemulsions.

[0067] Example 1 Preparation of water-in-oil droplets using a multi-channel microfluidic emulsification membrane containing 30 and 300 through-holes

[0068] The membrane pore size is 60×300μm, the pore depth is 500μm, and the spacing between pores in the first and second directions is 300μm. Ultrapure water is used as the dispersed phase, and HFE7500 containing 1% Krytox-COOH is used as the continuous phase.

[0069] The dispersed phase is pre-input into the liquid phase chamber through the input hole 1 to evacuate the gas inside the dispersed phase. After the continuous phase is injected into the emulsification tank, the emulsification device is placed so that the emulsification membrane is placed horizontally and the membrane holes are kept facing upward. The dispersed phase is input into the liquid phase chamber through the input hole 1 at a flow rate of 1 ml / min. The droplet formation on the surface of the multi-channel microfluidic emulsification membrane containing 30 through-holes is shown in Figure 5, and the droplet formation on the surface of the multi-channel microfluidic emulsification membrane containing 300 through-holes is shown in Figure 13, among which the droplet formation in a single emulsification hole is shown in Figure 6. The droplets generated by emulsification are automatically enriched on the liquid surface of the emulsification tank, as shown in Figure 7. The product can be obtained by taking the upper emulsion droplets.

[0070] Example 2 Preparation of Water-in-Oil Droplets Using Multi-channel Microfluidic Emulsification Membranes with Through-holes of Different Sizes

[0071] Membrane pore sizes ranged from 500×150μm, 1000×200μm, 1440×340μm, 3000×600μm, 4000×800μm, 6000×1200μm, and 8000×1600μm, with pore depths ranging from 500 to 8000μm. The pore depths were all equal to the long side length of the membrane pores, and the spacing between pores in the first and second directions was the same as the long side length. The multichannel microfluidic emulsification membrane was sealed within a liquid phase chamber to create an emulsification device. Ultrapure water was used as the dispersed phase, and HFE7500 containing 1% Krytox-COOH was used as the continuous phase. The dispersed phase was pre-injected through the input port to evacuate the gas inside the liquid phase chamber. After the continuous phase was injected into the emulsification cell, the emulsification device was placed, with the multichannel microfluidic emulsification membrane positioned horizontally with the pores facing upward. The dispersed phase was introduced through the input port, and droplet formation at different membrane pore sizes is shown in Figure 8. The droplets produced by emulsification are automatically enriched on the liquid surface of the emulsification pool. The product can be obtained by taking the upper layer of emulsion droplets. The size distribution of emulsion droplets produced by membranes of different specifications is shown in Figure 9.

[0072] Example 3 Preparation of Alginic Acid and Polyethylene Glycol Microgels Using Emulsified Membrane

[0073] The formulas of alginate (Alg) and polyethylene glycol diacrylate (PEGDA) prepolymer solutions are:

[0074] Alginic acid: 1% alginate solution dissolved in 50 mM calcium EDTA;

[0075] Polyethylene glycol dimethacrylate: a 10% solution of polyethylene glycol diacrylate (PEGDA600) with a molecular weight of 600 dissolved in 1% photoinitiator 2959.

[0076] The above-mentioned hydrogel prepolymer is used as the dispersed phase, and HFE7500 containing 1% Krytox-COOH is used as the continuous phase. The membrane pore size is 2000×400μm, the pore depth is 2000μm, the spacing between the pores in the first direction is 400μm, and the spacing between the pores in the second direction is 800μm. The multi-channel microfluidic emulsification membrane is sealed in the liquid phase chamber to obtain an emulsification device. The dispersed phase is pre-input through the input hole to evacuate the gas inside the liquid phase chamber. After the continuous phase is injected into the emulsification tank, it is placed in the emulsification device so that the emulsification membrane is placed horizontally and the membrane pores are kept facing upward. The dispersed phase is input through the input hole, and the emulsified droplets are automatically enriched on the liquid surface of the emulsification tank. Different curing methods are used to induce hydrogel curing (alginate: add glacial acetic acid solution to the emulsification tank; PEGDA600: with a wavelength of 365nm and a power of 2W / cm 2 The desired hydrogel product can be obtained after separation, as shown in Figure 10. The size distribution of different types of gels is shown in Figure 11.

[0077] Example 4 Preparation of Alginate Yin-Yang (Janus) Structure Microgel Using an Integrated Multilayer Emulsion Membrane

[0078] The formula of alginate (Alg) prepolymer is:

[0079] Alginate A: 1% 5-aminofluorescein-modified alginate solution dissolved in 50 mM calcium ethylenediaminetetraacetic acid;

[0080] Alginate B: 1% rhodamine B-modified alginate solution dissolved in 50 mM calcium EDTA;

[0081] The hydrogel prepolymer described above was used as the dispersed phase, and HFE7500 containing 1% Krytox-COOH was used as the continuous phase. The membrane pore size was 2000×400μm, with a pore depth of 2000μm and a spacing of 2000μm between the pores in both the first and second directions. Alginate A and Alginate B were placed in two separate liquid phase chambers, arranged one above the other. The upper chamber of Alginate A was directly connected to the multichannel microfluidic emulsification membrane, while the lower chamber of Alginate B was connected to each through-hole of the multichannel microfluidic emulsification membrane via 800×400μm input channels, with the outlets of the input channels below the top surface of the multichannel microfluidic emulsification membrane (Figure 14). The multichannel microfluidic emulsification membrane was sealed within the upper liquid phase chamber to obtain an emulsification device. The dispersed phase was pre-injected into each of the two liquid phase chambers through different input holes to evacuate the air from the liquid phase chambers. After the continuous phase is injected into the emulsification tank, the emulsification device is placed, with the emulsified membrane positioned horizontally with the membrane pores facing upward. Alginate A and alginic acid B are introduced into the two liquid phase chambers through different input ports. By controlling the flow rates of the different dispersed phases, multi-petal microgels with different chamber ratios are obtained. The emulsified droplets automatically accumulate on the surface of the emulsification tank. Glacial acetic acid solution is added to the emulsification tank to induce crosslinking of the yin-yang structured alginate microgels. After separation, the desired hydrogel product is obtained, as shown in Figure 17.

[0082] Example 5 Preparation of Alginate Core-Shell Microgel Using an Integrated Multilayer Emulsion Membrane

[0083] The formula of the alginate (Alg) shell prepolymer solution is: 1% 5-aminofluorescein-modified alginate solution dissolved in 50 mM calcium ethylenediaminetetraacetic acid;

[0084] The core prepolymer solution formula is: 10% rhodamine-modified dextran solution;

[0085] The above-mentioned prepolymer was used as the dispersed phase, and HFE7500 containing 1% Krytox-COOH was used as the continuous phase. The membrane pore size was 2000×400μm, the pore depth was 2000μm, and the spacing between the pores in the first and second directions was 2000μm. The shell prepolymer and the core prepolymer were placed in different liquid phase chambers. The shell prepolymer chamber was connected to the multichannel microfluidic emulsification membrane, and the core prepolymer chamber was connected to each through-hole of the multichannel microfluidic emulsification membrane via an input channel. The outlet of the input channel was lower than the top surface of the multichannel microfluidic emulsification membrane and was placed in the center of each through-hole (Figure 15) to ensure that the shell prepolymer entered the two sides of the through-hole and the core prepolymer entered the middle. Each through-hole had three 500×400μm emulsification channels, of which the two side emulsification channels input the shell prepolymer, and the middle emulsification channel was connected to the input channel to input the core prepolymer. The multichannel microfluidic emulsification membrane is encapsulated in a sealed liquid phase chamber to create an emulsification device. The dispersed phase is pre-injected into the two liquid phase chambers through different input ports to evacuate the air from the liquid phase chambers. After the continuous phase is injected into the emulsification tank, the emulsification device is placed, with the emulsification membrane positioned horizontally with the membrane holes facing upward. The dispersed phase is then fed into the two liquid phase chambers through different input ports. The resulting emulsified droplets are automatically accumulated on the liquid surface of the emulsification tank. Glacial acetic acid solution is added to the emulsification tank to induce crosslinking of the yin-yang structured alginate microgels. After separation, the desired hydrogel product is obtained, as shown in Figure 22.

[0086] Example 6 Preparation of Escherichia coli-loaded alginate microgels using an integrated multi-channel microfluidic emulsification membrane

[0087] The formula of alginate (Alg) prepolymer solution is: E. coli concentration is 10 10 / ml, 1% alginate solution containing 50 mM calcium EDTA;

[0088] The above-mentioned hydrogel prepolymer was used as the dispersed phase, and HFE7500 containing 1% Krytox-COOH was used as the continuous phase. The membrane pore size was 3000 × 1500 μm, the pore depth was 10,000 μm, and the spacing between pores in the first and second directions was 200 μm. As in Example 3, glacial acetic acid solution was added to the emulsification tank to induce cross-linking of the alginate microgel. After separation, the desired hydrogel product was obtained, as shown in Figure 19.

[0089] Example 7 Preparation of Alginate Microgels Carrying Rat Mesenchymal Stem Cells Using an Integrated Multichannel Microfluidic Emulsion Membrane

[0090] The formula of alginate (Alg) prepolymer solution is: the concentration of rat mesenchymal stem cells transfected with green fluorescent protein is 4x10 6 / ml, 1% alginate solution containing 50 mM calcium EDTA;

[0091] The above-mentioned hydrogel prepolymer was used as the dispersed phase, and HFE7500 containing 1% Krytox-COOH was used as the continuous phase. The membrane pore size was 50 × 5 μm, the pore depth was 50 μm, and the spacing between pores in the first and second directions was 1000 μm. As in Example 3, glacial acetic acid solution was added to the emulsification tank to induce crosslinking of the anionic and anionic alginate microgels. After separation, the desired hydrogel product was obtained, as shown in Figure 18.

[0092] Example 8 Preparation of Alginate Yin-Yang (Janus) Structure Cell-Laden Microgels Using an Integrated Multi-Channel Microfluidic Emulsion Membrane

[0093] The formula of alginate (Alg) prepolymer is:

[0094] Alginate A: 1% 5-aminofluorescein modified alginate solution dissolved in 50 mM calcium ethylenediaminetetraacetic acid, containing 2 × 10 6 / ml rat mesenchymal stem cells;

[0095] Alginate B: Arginine-glycine-aspartic acid fragment modified alginate solution dissolved in 50 mM calcium ethylenediaminetetraacetic acid, containing 2×10 6 / ml green fluorescent protein-transfected HeLa cells;

[0096] The above-mentioned hydrogel prepolymer was used as the dispersed phase, and HFE7500 containing 1% Krytox-COOH was used as the continuous phase. The membrane pore size was 2000×400 μm, the pore depth was 2000 μm, and the spacing between pores in the first and second directions was 2000 μm. Alginate A and alginic acid B were placed in different liquid phase chambers. The chamber for alginic acid A was directly connected to the multichannel microfluidic emulsion membrane, while the chamber for alginic acid B was connected to each through-hole of the multichannel microfluidic emulsion membrane via an 800×400 μm input channel, with the outlet of the input channel below the top surface of the multichannel microfluidic emulsion membrane (Figure 14). As in Example 4, glacial acetic acid solution was added to the emulsification tank to induce crosslinking of the yin-yang structured alginate microgel. After separation, the desired cell-laden microgel product was obtained, as shown in Figure 16. The nuclei of rat mesenchymal stem cells were stained with DAPI, showing blue fluorescence.

[0097] Example 9 Preparation of Alginate Microgels Carrying Magnetic Particles Using an Integrated Single-Layer Multi-Channel Microfluidic Emulsion Membrane

[0098] The formula of alginate (Alg) prepolymer solution is: 1% alginate solution containing 1% ferroferric oxide nanoparticles and 50 mM calcium ethylenediaminetetraacetic acid;

[0099] The hydrogel prepolymer described above was used as the dispersed phase, and soybean oil containing 1% TWEEN-80 was used as the continuous phase. The membrane pore size was 500 × 100 μm, the pore depth was 1000 μm, and the spacing between pores in both the first and second directions was 1000 μm. The multichannel microfluidic emulsification membrane was sealed within a liquid phase chamber to form an emulsification device. The input port of the emulsification device was connected to the dispersed phase input pipeline, and the dispersed phase was pre-injected to evacuate the gas within the dispersed phase. After the continuous phase was injected into the emulsification tank, the emulsification tank was placed above a rubidium magnet. The emulsification device was placed within the emulsification tank, with the multichannel microfluidic emulsification membrane positioned horizontally with the membrane pores facing downward and facing the rubidium magnet. A parallel magnetic field was introduced perpendicular to the multichannel microfluidic emulsification membrane. The dispersed phase was introduced through the input port, and the resulting emulsified droplets accumulated automatically at the bottom of the emulsification tank. Glacial acetic acid solution was added to the emulsification tank to induce crosslinking of the alginate microgels. After separation, the desired hydrogel product was obtained, as shown in Figure 20.

[0100] Example 10 Preparation of polymethyl methacrylate (PMMA) microparticles based on electric field force using an integrated multi-channel microfluidic emulsification membrane

[0101] The formula of polymethyl methacrylate (PMMA) prepolymer solution is: 1% by mass of photoinitiator 1173 and 20% by mass of methyl methacrylate dissolved in toluene solution;

[0102] The prepolymer described above serves as the dispersed phase, and HFE7500 fluorinated liquid containing 1% perfluoropolyether surfactant serves as the continuous phase. The membrane pore size is 400 × 80 μm, the pore depth is 1000 μm, and the spacing between pores in the first and second directions is 600 μm. The membrane surface is silver-plated. After sealing in a liquid phase chamber, the emulsification device is assembled. The inlet port of the emulsification device is connected to the inlet pipe of the dispersed phase. The dispersed phase is pre-injected to evacuate the gas within the dispersed phase. A grounding wire is then introduced into the liquid phase chamber to ground the dispersed phase. After the continuous phase is injected into the emulsification cell, the cell is placed on a high-voltage flat electrode and the voltage is adjusted to 20 kV. The emulsification device is then placed into the cell, with the multi-channel microfluidic emulsification membrane positioned horizontally with the membrane pores facing downward, as shown in Figure 24. The dispersed phase is then introduced, and the resulting emulsified droplets automatically accumulate at the bottom of the cell. The emulsion at the bottom of the cell is then irradiated with a UV light source, and the desired microparticle product is obtained after separation, as shown in Figure 21.

[0103] Example 11 Using a single-layer multi-channel microfluidic emulsification membrane, high-throughput preparation of polyethylene glycol dimethacrylate (PEGDA) microparticles based on centrifugal force

[0104] The formula of polyethylene glycol dimethacrylate (PEGDA) prepolymer solution is: ethylene glycol diacrylate (EGDMA) solution containing 1% by mass of photoinitiator 614;

[0105] The prepolymer described above is used as the dispersed phase, and an aqueous solution containing 20% ​​polyvinyl alcohol is used as the continuous phase. The membrane pore size is 400×80μm, the pore depth is 1000μm, and the spacing between the pores in the first and second directions is 600μm. After being sealed in a liquid phase chamber, an emulsification device is obtained. The input port of the emulsification device is connected to the input pipeline of the dispersed phase, and the dispersed phase is pre-injected to evacuate the gas inside the dispersed phase. The emulsification tank is placed on a centrifugal device, and the emulsification device is placed in the emulsification tank, so that the multi-channel microfluidic emulsification membrane is perpendicular to the centrifugal radius. The centrifugal device is started, the dispersed phase is introduced, and the emulsification process is initiated, as shown in Figure 25. After emulsification is completed, the centrifuge is turned off, and the emulsion product naturally settles to the bottom of the emulsification tank. The emulsion at the bottom of the emulsification tank is irradiated with an ultraviolet light source, and the desired microparticle product is obtained after separation, as shown in Figure 23.

[0106] Example 12 Preparation of Water-in-Oil Droplets Using a Multichannel Microfluidic Emulsification Membrane with Irregularly Arranged Rectangular Holes

[0107] The membrane pore size is 300×60μm, with a pore depth of 500μm. Each through-hole is independently and randomly arranged, as shown in Figure 26. Figure 26 shows three emulsification membranes formed by random arrangement. These three multichannel microfluidic emulsification membranes are sealed in a liquid phase chamber to obtain an emulsification device. Ultrapure water is used as the dispersed phase, and HFE7500 containing 1% Krytox-COOH is used as the continuous phase. The dispersed phase is pre-injected through the input hole to evacuate the gas inside the liquid phase chamber. After the continuous phase is injected into the emulsification tank, it is placed in the emulsification device, with the multichannel microfluidic emulsification membrane placed horizontally with the membrane pores facing upward, and the dispersed phase is injected through the input hole. The droplets generated by emulsification are automatically enriched on the liquid surface of the emulsification tank, and the product is obtained by taking the upper layer of emulsion droplets. The droplet size distributions produced by the membrane structures formed by the three different random arrangements of rectangular holes are the same and similar to the droplet products obtained by the through-holes arranged in an array of the same specifications (Figure 13). The droplet size difference coefficients are all <3%, as shown in Figure 27.

[0108] Anyone skilled in the art will be able to utilize the above-disclosed technical content to make many possible changes and modifications to the technical solution of the present invention, or to modify it into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention that do not depart from the content of the technical solution of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A multi-channel microfluidic emulsification membrane for producing monodisperse emulsion droplets, characterized in that: It comprises at least one through hole, the cross section of the through hole is rectangular, the short side length of the cross section is 0.005-1.5 mm, preferably, the short side length of the cross section is 0.01-0.5 mm, and the length ratio of the short side to the long side is 1:2-1:

10.

2. The multi-channel microfluidic emulsification membrane according to claim 1, characterized in that: The through holes are independently randomly arranged or independently arranged in a rectangular array; preferably, the through holes are arranged in a rectangular array, and the spacing between the through holes in the first direction is 0.2-20 times the length of the long side, and the spacing between the through holes in the second direction is 0.4-20 times the length of the long side.

3. The multi-channel microfluidic emulsification membrane according to claim 1, characterized in that: The thickness of the multi-channel microfluid emulsification membrane is 0.01 mm-10 mm, and the depth of the through hole is more than 1 times the length of the long side.

4. The multi-channel microfluidic emulsification membrane according to claim 1, characterized in that: The multi-channel microfluidic emulsification membrane is made of one or more combinations of glass, silicon, metal, ceramic, organic polymer, or organic-inorganic composite materials, and the through holes are processed by laser, drilling, etching, 3D printing or integral molding.

5. The multi-channel microfluidic emulsification membrane according to claim 1, characterized in that: The through hole array is located in the center of the multi-channel microfluidic emulsification membrane plane, and a blank area is left at the edge of the membrane without through holes, wherein the straight-line distance between the through holes outside the through hole array and the membrane edge is greater than twice the length of the long side.

6. A monodisperse emulsion droplet preparation device based on a multi-channel microfluidic emulsification membrane, characterized in that: It comprises the multi-channel microfluidic emulsification membrane as claimed in claim 1, wherein the multi-channel microfluidic emulsification membrane is encapsulated in a liquid phase chamber to seal the liquid phase chamber, and the emulsification device is provided with an input hole for introducing a dispersed phase into the liquid phase chamber.

7. The monodisperse emulsion droplet preparation device based on a multi-channel microfluidic emulsification membrane according to claim 6, characterized in that: When there are multiple liquid phase chambers, the number of input holes is the same as the number of liquid phase chambers and corresponds one to one; multiple liquid phase chambers are arranged in layers, and the liquid phase chambers that are not directly connected to the multi-channel microfluidic emulsification membrane are connected to the multi-channel microfluidic emulsification membrane through input channels, and the outlets of the input channels are lower than the upper surfaces of the through holes of the multi-channel microfluidic emulsification membrane. The number of input channels is consistent with the number of through holes of the multi-channel microfluidic emulsification membrane, and the input channels correspond one to one with the through holes of the multi-channel microfluidic emulsification membrane; preferably, the input channel is placed at the center of each through hole.

8. A method for large-scale preparation of monodisperse emulsion droplets, characterized in that: The method comprises using the emulsification device according to claim 6 or 7, comprising the following steps: (1) placing an emulsification device in a continuous phase, so that the dispersed phase and the continuous phase are placed on both sides of a multi-channel microfluidic emulsification membrane; (2) introducing a dispersed phase into the liquid phase chamber, and the dispersed phase enters the continuous phase through the through holes of the multi-channel microfluidic emulsification membrane, and completes continuous emulsification under the induction of an emulsification control factor; the emulsification control factor is selected from one or more of buoyancy, gravity, centrifugal force, electric field force, and magnetic force.

9. The method for large-scale preparation of monodisperse emulsion droplets according to claim 8, wherein when the emulsification control factor is the buoyancy factor, the density difference between the continuous phase and the dispersed phase is greater than 0.2 g / ml, preferably, the density difference ranges from 0.3 to 0.6 g / ml; if the density of the dispersed phase is greater than that of the continuous phase, the multi-channel microfluidic emulsification membrane is placed horizontally, with the dispersed phase placed above the membrane and the continuous phase placed below the membrane; otherwise, the positions of the dispersed phase and the continuous phase are swapped; When the emulsification control factor is gravity, the continuous phase is selected as gas phase; the multi-channel microfluidic emulsification membrane is placed horizontally, the dispersed phase is placed above the membrane, and the continuous phase is placed below the membrane; When the emulsification control factor is the centrifugal force factor, the centrifugal force is provided by a centrifugal device, the density of the dispersed phase is greater than that of the continuous phase, and preferably, the density difference ranges from 0.1 to 0.4 g / ml; the membrane surface of the multi-channel microfluidic emulsification membrane is placed perpendicular to the centrifugal radius, the dispersed phase is placed in the membrane close to the centrifugal center, and the continuous phase is placed away from the centrifugal center; When the emulsification control factor is an electric field force factor, an electrostatic generating device is used to generate an electric field, and the surface of the multi-channel microfluidic emulsification membrane is subjected to gold spraying, or a metal-based multi-channel microfluidic emulsification membrane is used, and the continuous phase is an insulating material; a flat electrode with an area larger than the multi-channel microfluidic emulsification membrane is connected to the electrostatic generating device and placed horizontally to the multi-channel microfluidic emulsification membrane, and the multi-channel microfluidic emulsification membrane is grounded; When the emulsification control factor is a magnetic factor, a magnetic material is introduced into the continuous phase, and a parallel magnetic field is introduced perpendicular to the multi-channel microfluidic emulsification membrane.

10. Use of the multi-channel microfluidic emulsification membrane according to claim 1 or the device according to claims 6 and 7 in large-scale production of monodisperse emulsion droplets.

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