Hydrophilic and hydrophobic patterned substrate circulation microchannel reactor and preparation method thereof

Abstract

The present invention discloses a hydrophilic-hydrophobic patterned substrate circulation microchannel reactor and a preparation method thereof, wherein the reactor comprises a first region and a microchannel region arranged side by side, wherein the first region and the microchannel region are connected; the first region comprises a first hydrophilic region and a hydrophobic region arranged in sequence; along the flow direction of the liquid, the size of the first hydrophilic region gradually decreases; the microchannel region comprises a microwall and a fluid channel region arranged in sequence, wherein the first hydrophilic region and the hydrophobic region are both connected to the fluid channel region; a nanocatalyst layer and / or a biological enzyme are also provided on the surface of the fluid channel region; when the liquid circulates in the first region and the microchannel region, it is in a circulation shape. The technology of the present invention is simple and fast, flexible and easy to use, and is suitable for a variety of catalytic reactions and reactors of various forms, and is convenient for large-scale production. The miniaturization and high efficiency of the catalytic reaction make it have strong application value in the safe chemical industry, green chemical industry, and efficient chemical industry.

Description

Technical Field

[0001] The invention relates to a microchannel reactor, in particular to a hydrophilic-hydrophobic patterned substrate circulation microchannel reactor and a preparation method thereof. Background Art

[0002] In chemical reactions, incomplete mixing of reaction liquids and inefficient catalytic processes waste a lot of time and energy. There is a reaction active layer around the catalyst, and the reactants in the active layer can react. The liquid phase catalytic reaction process is: diffusion of reactants, adsorption of reactants on the catalyst surface, catalytic reaction to produce products, desorption of products from the catalyst surface, and diffusion of products. In general chemical catalytic reaction processes, the diffusion and adsorption and desorption of reactants and products often take a long time (20-60 minutes), there is a certain distance between the reactants and the catalyst, and many reactant molecules need to "queue" to wait for participation in the reaction. Therefore, if the "distance" can be shortened and the "waiting time" can be reduced, the reaction efficiency can be greatly improved.

[0003] Microfluidics refers to the science and technology involved in systems that use microchannels (tens to hundreds of microns in size) to process or manipulate tiny fluids (volumes from nanoliters to microliters). It is an emerging interdisciplinary subject involving chemistry, fluid physics, new materials, biology, and biomedical engineering. The behavior of fluids in microchannels of microfluidics is different from that in macroscale channels. These fluid behaviors (phenomena) are not only important features and signs of microfluidics, but also convenient and unique technical means. The main fluid phenomena are laminar flow and droplet behavior manipulation. With these unique fluid phenomena, microfluidics can achieve a series of micromachining and micromanipulation that are difficult to accomplish with conventional methods. Through the microfluidic method, the "distance" between reactants and catalysts can be effectively shortened, and the "waiting time" of reactants can be reduced, which can greatly improve the reaction efficiency.

[0004] Traditional methods for preparing microfluidic microchannels are mostly laser etching, 3D printing, atomic layer deposition, etc. These methods can quickly and accurately prepare controllable micro-nano structures, which are of great significance for the device application of functional materials. However, these methods are costly and time-consuming. For example, laser etching (including mask preparation and etching) takes several weeks to prepare micro-nano structures, and also involves the use of photoresist, a material with high environmental pollution. Scribing is a low-cost, fast (1-5 hours depending on the complexity of the structure), and pollution-free method for preparing micro-nano structures, with an accuracy of up to (20±5) microns, which meets the requirements of most micro-nano structure processing.

[0005] In recent years, micro-template nanoprinting technology has been able to achieve cross-scale printing and manufacturing of multiple functional materials, and has been applied in the fields of wearable electronics, flexible displays, micro-nano circuits, etc. The micro-template printing is used to control the combination of functional material droplets and self-assembly, and the characteristic pattern structure on the micro-template is used to induce orderly shrinkage molding, so that the characteristic size of the final printed and assembled micro-nano pattern can be much smaller than the characteristic pattern on the micro-template. It is an effective micro-nano material processing method. Summary of the invention

[0006] One of the purposes of the present invention is to provide a hydrophilic-hydrophobic patterned substrate circulation microchannel reactor, in which a micron-scale hydrophilic-hydrophobic region is set at the inlet end of the microchannel reactor, and the inlet droplets are divided by the difference in the hydrophilic-hydrophobic regions. The droplets are sucked into the microchannel area by capillary force, thereby initiating the flow of liquid in the microchannel area and forming a circulation between multiple channels to increase the flow rate.

[0007] The technical solution of the present invention is:

[0008] A hydrophilic-hydrophobic patterned substrate circulation microchannel reactor, the reactor comprising a first region and a microchannel region arranged side by side, the first region and the microchannel region being connected;

[0009] The first region includes a first hydrophilic region and a hydrophobic region that are sequentially spaced apart; along the liquid flow direction, the size of the first hydrophilic region gradually decreases;

[0010] The microchannel area includes microwalls and a fluid channel area that are sequentially spaced apart, and the first hydrophilic area and the hydrophobic area are both connected to the fluid channel area; a nano catalyst layer and / or a biological enzyme is also provided on the surface of the fluid channel area;

[0011] When the liquid flows through the first region and the microchannel region, it is in a circular flow.

[0012] The reactor described in the present invention does not require an external pressure pump. At the front end of the microchannel area, the first hydrophilic area and the hydrophobic area divide the injected droplets, and the capillary force of the nanocatalyst and / or the biological enzyme is used to suck the liquid into the fluid channel area. The difference between the hydrophilic and hydrophobic areas and the solvent evaporation drive the liquid to circulate in a directed manner in the reactor.

[0013] In the present invention, the gradually decreasing size of the first hydrophilic region means that when the liquid spreads toward the microchannel region, the cross-sectional area of ​​the liquid spreads becomes smaller and smaller.

[0014] According to the present invention, the reactor further comprises a second region, the microchannel region is located between the first region and the second region, and the second region is a second hydrophilic region.

[0015] According to the present invention, the shape of the first hydrophilic area is a trapezoidal structure.

[0016] According to the present invention, the first region comprises at least one liquid inlet zone; the liquid inlet zone is used for liquid to enter the reactor.

[0017] Preferably, the liquid inlet area includes a first hydrophilic area and a hydrophobic area which are sequentially arranged at intervals.

[0018] According to the present invention, the first region further comprises a liquid injection area, which is arranged side by side with the liquid inlet area and is close to the microchannel area; the liquid injection area comprises a first hydrophilic area and a hydrophobic area which are arranged in sequence.

[0019] Preferably, the liquid inlet area and the liquid injection area together form the first region.

[0020] According to the present invention, the length of the microchannel area is greater than the length of the liquid injection area and greater than or equal to the length of the liquid inlet area.

[0021] According to the present invention, the thickness of the nanocatalyst and / or biological enzyme is 0.5-5 micrometers, preferably 0.5-2 nanometers.

[0022] According to the present invention, the particle size of the nanocatalyst is 2nm to 900nm. The nanocatalyst can be, but is not limited to, one or more of colloidal microspheres, nanoparticles (such as platinum, gold, silver, copper, zinc oxide, iron oxide, ferroferric oxide, titanium dioxide, silicon dioxide, CdTe quantum dots, etc.), carbon nanotubes, and graphene; or one or more of the core-shell structures of PS nanomicrospheres or infinite nanospheres as cores, and the cores are coated with platinum shells, gold shells, silver shells, copper shells, DNA molecules, organic fluorescent molecules (such as FITC, 6-carboxylic acid fluorescein, sodium fluorescein, etc.), functional organic small molecules (such as vitamins) or functional polymers (polyimide membranes, sodium polystyrene sulfonate, polyvinyl chloride membranes, carboxylated cellulose, etc.).

[0023] The enzyme may be, but is not limited to, one or more of lipase CAL-b, trypsin, sucrose phosphorylase, aminoacylase, glucose isomerase, manganese peroxidase, laccase, ribulose-1,5-bisphosphate carboxylase, α-amylase, urease, cellulase, and the like.

[0024] According to the present invention, the center distance between adjacent microwalls is less than 100 microns, for example, it can be 5 microns, 10 microns, 20 microns, 30 microns, 50 microns, 60 microns, 70 microns, 80 microns, 90 microns, or 99 microns.

[0025] According to the present invention, the height of the micro-wall is 15-25 microns, preferably 25 microns; the average width of the micro-wall is 10-50 microns, preferably 20 microns. The average width of each micro-wall can be the same or different.

[0026] According to the present invention, the material of the bottom surface of the microchannel area is the same as or different from the material of the first hydrophilic area, and both are selected from hydrophilic materials; the material of the hydrophobic area is a hydrophobic material. The hydrophilic material may be a hydrophilic group grafted on the surface of the substrate; the hydrophilic group may be, for example, a sulfonic acid group, a sulfuric acid group, a phosphoric acid group, a carboxylic acid group, an amino group, a quaternary ammonium group, a carboxylic acid ester, etc.; for example, the hydrophobic material may be a hydrophobic group grafted on the surface of the substrate, and the hydrophobic group may be, for example, a hydrocarbon group, such as C 1-20 alkyl.

[0027] The first hydrophilic region refers to a planar region formed by grafting hydrophilic groups on the surface of the substrate; and the hydrophobic region refers to a planar region formed by grafting hydrophobic groups on the surface of the substrate.

[0028] According to the present invention, the material of the micro wall is at least one of polydimethylsiloxane, copolyester, polyvinyl alcohol, polycarbonate, polyvinyl chloride, cellulose acetate, ethyl cellulose, vinyl alcohol-vinyl acetate, ethylene-propylene polymer and sodium alginate, preferably polydimethylsiloxane.

[0029] According to the present invention, the fluid channel area is formed between adjacent micro-walls. The micro-wall is a three-dimensional structure.

[0030] According to the present invention, the fluid channel area is formed by seamlessly combining a substrate and a plurality of micro walls.

[0031] According to the present invention, the substrate can be one or more materials such as silicon, metal, etc. The silicon is, for example, a glass sheet, a single crystal silicon sheet, a silicon dioxide sheet, a quartz sheet or a polydimethylsiloxane film, etc. The metal is, for example, an aluminum sheet, a copper sheet, a nickel sheet or an aluminum oxide sheet, etc.; preferably, an aluminum sheet or a glass sheet.

[0032] The present invention also provides a method for preparing the above-mentioned hydrophilic and hydrophobic patterned substrate circulation microchannel reactor, the method comprising the following steps:

[0033] (1) preparing a substrate containing a hydrophilic-hydrophobic pattern, wherein the substrate containing a hydrophilic-hydrophobic pattern comprises a bottom surface of the microchannel region, and a first hydrophilic region and a hydrophobic region containing the above structure;

[0034] (2) preparing a micro-wall on the bottom surface of the micro-channel area in step (1), so that the micro-channel area is sequentially provided with micro-walls and fluid channel areas, and then preparing a nano-catalyst layer and / or biological enzyme on the surface of the fluid channel area to prepare a micro-channel reactor.

[0035] According to the present invention, in step (1), the substrate containing the hydrophilic and hydrophobic pattern may further include a bottom surface of the second region.

[0036] According to the present invention, in step (1), before modification, the substrate may be subjected to oxidation treatment using an acidic solution or an alkaline solution; the acidic solution may be at least one of sulfuric acid and hydrogen peroxide; preferably, it is a piranha solution, wherein the volume ratio of sulfuric acid to hydrogen peroxide is, for example, 3:1; the alkaline solution may be at least one of an alkali metal solution and an alkaline earth metal solution, for example, a sodium hydroxide solution.

[0037] Exemplarily, the silicon substrate is oxidized using an acidic solution, and the metal substrate is oxidized using an alkaline solution.

[0038] According to a preferred embodiment of the present invention, the specific steps of oxidation treatment of the silicon substrate using an acidic solution are: immersing the silicon substrate in an acidic solution, heating at 120-150° C. for 1-2 hours, taking out the silicon substrate, washing it with deionized water, and drying it to prepare a substrate after surface oxidation treatment, for example, by drying with high-purity nitrogen.

[0039] According to a preferred embodiment of the present invention, the specific steps of oxidizing the metal substrate with an alkaline solution are as follows: immersing the metal substrate in the alkaline solution, reacting at 20-40°C for 3-5 minutes, immediately taking out the metal substrate, washing it with deionized water, immersing it in deionized water, heating it at 80-100°C for 20-40 minutes, taking it out and drying it to prepare a substrate after surface oxidation treatment. For example, high-purity nitrogen is used for drying.

[0040] Preferably, before deionized water cleaning, the reaction temperature is preferably 30° C., and the reaction time is preferably 3 min.

[0041] Preferably, after deionized water cleaning, the reaction temperature is preferably 90° C., and the reaction time is preferably 30 min.

[0042] Preferably, the concentration of the alkaline solution is 0.2-0.7 mol / L, preferably 0.5 mol / L. For example, the concentration of the sodium hydroxide solution is 0.5 mol / L.

[0043] According to the present invention, in step (1), the specific preparation steps of the substrate containing hydrophilic and hydrophobic patterns are: reacting the substrate after surface oxidation treatment with a silane coupling agent, then covering the top of the substrate with a mask (film), and then irradiating the top of the mask (film) with ultraviolet light to prepare the substrate containing hydrophilic and hydrophobic patterns; wherein the structure of the mask is consistent with the structure of the substrate containing hydrophilic and hydrophobic patterns, the hydrophilic area of ​​the substrate containing hydrophilic and hydrophobic patterns corresponds to the light-transmitting area of ​​the mask, and the hydrophobic area of ​​the substrate containing hydrophilic and hydrophobic patterns corresponds to the light-opaque area of ​​the mask.

[0044] According to the present invention, the mask plate includes a fourth area and a fifth area arranged side by side, the fourth area and the fifth area are connected, the fourth area contains a light-transmitting area and a non-light-transmitting area arranged in sequence at intervals, and the cross-section of the light-transmitting area is preferably an isosceles trapezoid; the fifth area is a light-transmitting area.

[0045] Preferably, the mask further includes a sixth region; the fifth region is located between the fourth region and the sixth region, and the sixth region is a second hydrophilic region.

[0046] The ultraviolet light irradiation refers to reacting the surface-oxidized substrate with a silane coupling agent, tightly covering the mask (film) plate, and then exposing it to ultraviolet light to obtain a substrate containing a hydrophilic and hydrophobic pattern. The preparation process is as follows: Fig.18 shown.

[0047] Wherein, the ultraviolet light irradiation time is 6-20 hours, preferably 8 hours.

[0048] The mask (film) plate is a plate with light-transmitting areas and opaque areas, such as a quartz mask (film) plate or a metal mask (film) plate. The metal mask plate is, for example, one of a molybdenum plate, a copper plate, a nickel plate, etc., preferably a molybdenum plate.

[0049] According to the present invention, in step (2), a nano catalyst layer and / or a biological enzyme is attached to the surface of the fluid channel region using micro-nano self-assembly technology or an enzyme immobilization method.

[0050] The present invention injects reaction liquid into one side of the microchannel area (such as the injection area), utilizes the difference in hydrophilic areas and solvent evaporation to induce directional circulation of the reaction liquid, and can promote the adsorption and desorption of reactants and products during the catalytic reaction, reduce the energy and time consumed by the reactants and products due to the diffusion process, and thus achieve the purpose of improving the efficiency of the catalytic reaction.

[0051] Among them, the micro-nano self-assembly technology refers to the dispersion of nanocatalyst in a solvent. After the solvent evaporates, it spontaneously adsorbs on the inner wall of the fluid channel area to form a nanocatalyst layer, and the particles are arranged closely and neatly.

[0052] According to the present invention, the nano catalyst dispersion is composed of nano catalyst particles, a surfactant and a solvent.

[0053] According to the present invention, the surfactant may be, but is not limited to, at least one of anionic surfactants, cationic surfactants, zwitterionic surfactants, and nonionic surfactants. The anionic surfactant may be, for example, sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, or stearic acid, etc. The cationic surfactant may be, for example, a quaternary ammonium compound (e.g., alkyl dimethyl benzyl ammonium chloride, alkyl dimethyl ethyl benzyl ammonium chloride, etc.; the zwitterionic surfactant may be, for example, an amino acid, betaine, polyacrylamide, lecithin, etc.; the nonionic surfactant may be, for example, one of fatty acid sorbitan, fatty acid glyceride, polysorbate, and Tween; preferably, sodium dodecylbenzenesulfonate.

[0054] The solvent may be, but is not limited to, one or more of water, methanol, ethanol, acetone, ethylene glycol, isopropanol, diethylene glycol, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol butyl ether, ethylene glycol phenyl ether, ethylene glycol benzyl ether, conanol, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol butyl ether, triethylene glycol methyl ether, diacetone alcohol, tridecanol, tetradecanol, dioctyl phthalate, ethyl acetate, butyl acetate, cyclohexanone, xylene, bicyclohexane, cyclohexane, n-butanol, butanone, dimethyl phthalate, and sorbitol.

[0055] According to a preferred embodiment of the present invention, the micro-nano self-assembly technology can, for example, adopt the following steps: uniformly mix the microchannel region and the nanocatalyst dispersion, dry at 50-80°C for 5-60 minutes, and after the solvent in the nanocatalyst dispersion is completely evaporated, prepare a microchannel region loaded with a nanocatalyst layer.

[0056] The thickness of the nanocatalyst layer can be controlled by the mass content of the nanocatalyst in the dispersion during the assembly process. The concentration of the nanocatalyst dispersion is 5-20 mg / mL, preferably 10 mg / mL. The thickness of the nanocatalyst layer is 0.5-5 microns, preferably 0.5-2 nm microns.

[0057] According to the present invention, the enzyme fixation method can be but is not limited to one or more of polymethyl methacrylate (PMMA) physical adsorption, titanium dioxide / alumina sol-gel encapsulation, protein-modified silica (Zbasic2) fixation, lysine-assisted cross-linking polymerization to form enzyme polymer membrane, ion exchange resin fixation, mesoporous silica fixation, gel polyvinyl alcohol (PVA) fixation, polydopamine fixation, alginate embedding, and polyacrylamide embedding.

[0058] According to the present invention, the specific steps of reacting the substrate after surface oxidation treatment with the silane coupling agent are: drying the substrate after surface oxidation treatment with nitrogen and placing it in a vacuum dryer, then adding 0.5-2mL of silane coupling agent to a glass dish in the dryer, vacuumizing for 5-30 minutes, continuously heating at 80°C or higher for 1-2 hours, cooling, and taking it out for use. Among them, the silane coupling agent is preferably 1.5mL; the vacuumizing time is preferably 10 minutes; the heating temperature is preferably 80°C, and the heating time is preferably 1.5 hours.

[0059] The silane coupling agent may be one or more of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (PFOS), γ-(methacryloyloxy)propyltrimethoxysilane (GPTS), 3-aminopropyltrimethoxysilane (APTS), n-octyltriethoxysilane (OTES), n-decyltrichlorosilane (DTCS), etc., preferably 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (PFOS).

[0060] like Fig.21 As shown, the dimensions of the substrate containing the hydrophilic-hydrophobic pattern are: the inlet width (or longest side) a of the first hydrophilic zone is 100-1000 microns, the outlet width (or shortest side) b of the first hydrophilic zone is 100-1000 microns, the length c of the first hydrophilic zone is 1500-5000 microns, the length d of the liquid inlet zone in the first hydrophilic zone is 1000-2500 microns, the length e of the microchannel zone is greater than 5 mm, the width f of the first region or the microchannel zone is greater than 5 mm, wherein a is greater than b; preferably, a=800 microns, b=400 microns, c=2500 microns, d=1500 microns, e=10 mm, and f is 10 mm to 25 mm.

[0061] The micro-wall is prepared by a slicing method, and the sizes of the multiple micro-walls in the micro-channel area can be the same or different.

[0062] According to a preferred embodiment of the present invention, the specific preparation steps of the micro-wall are as follows: take a polished silicon wafer, use a dicing machine to cut the silicon wafer into a plurality of groove structures, continue to perform surface hydrophobic treatment on the silicon wafer after plasma surface treatment, and prepare a modified silicon wafer. Pour dimethylsiloxane and a curing agent on the surface of the modified silicon wafer (i.e., in the groove), heat, cool, and peel polydimethylsiloxane (PDMS) from the silicon wafer to obtain a micro-wall template, wherein the micro-wall template contains a plurality of micro-walls.

[0063] The groove structure is the same as the structure of the micro-wall, that is, the groove structure is used to cast the reaction raw materials of the micro-wall, and after the reaction of the reaction raw materials of the micro-wall is completed, it is peeled off from the groove structure to prepare a plurality of micro-walls, that is, a micro-wall template, in which the channels between adjacent micro-walls are the fluid channel areas.

[0064] In the present invention, the plasma processing conditions are, for example, air conditions, a power of 200 W, and a processing time of 300 s.

[0065] In the present invention, the hydrophobic treatment step of the silicon wafer surface is: placing the silicon wafer in a vacuum dryer containing trifluoromethyltrimethylsilane, and keeping the temperature at 70-100° C. for 20-60 minutes to prepare a modified silicon wafer. Preferably, the drying temperature is 90° C. and the drying time is 30 minutes.

[0066] In the present invention, Fig. 20 As shown, in the fluid channel area connected to the first hydrophilic area, the liquid flows in the positive direction, and in the fluid channel area connected to the hydrophobic area, the liquid flows in the negative direction.

[0067] The solvent evaporation may be natural evaporation at room temperature, heating evaporation, reduced pressure evaporation, etc., as long as the structure of the microchannel reactor is not destroyed and the catalytic reaction is not affected.

[0068] In the present invention, under the same first region and evaporation conditions, the smaller the cross-sectional area of ​​the fluid channel region in the microchannel region, the faster the reaction liquid flow rate.

[0069] The present invention can control the spreading behavior of droplets by manufacturing hydrophilic and hydrophobic regions with regional differences in wettability. By designing the spacing structure of the first hydrophilic region and the hydrophobic region, the droplets can be effectively divided when the liquid just enters, forming a phenomenon in which there are droplets in the hydrophilic region and no droplets in the hydrophobic region. The driving force of the droplets in the hydrophilic region comes from the gradient Laplace pressure inside the droplets, and the continuous change of its physical form enables liquid self-transport on the one-dimensional conical structure. The axial force generated by the different curvature pressures at both ends of the conical capillary drives the wettable droplets to move toward the narrow mouth, that is, to flow toward the microchannel area.

[0070] Beneficial Effects

[0071] The present invention utilizes micro-nano self-assembly technology to prepare a microchannel region containing a nano-catalytic structure layer and / or a biological enzyme, and controls the flow rate by controlling the cross-sectional size of the fluid channel region, thereby affecting the macroscopic reaction rate. The technology of the present invention is simple and fast, flexible and easy to use, and is applicable to a variety of catalytic reactions and reactors of various forms, and is convenient for large-scale production. The miniaturization and high efficiency of the catalytic reaction make it have strong application value in the safe chemical industry, green chemical industry, and efficient chemical industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 It is a plan view of the mask (film) plate in Example 1 of the present invention; the white area is the light-transmitting area, and the other areas are the non-light-transmitting areas.

[0073] Figure 2 This is a contact angle change diagram of the aluminum sheet in Example 1 of the present invention after surface oxidation treatment and silane coupling agent treatment.

[0074] Figure 3 This is a contact angle diagram of the exposed area and the non-exposed area after the aluminum sheet treated with a silane coupling agent in Example 1 of the present invention is subjected to ultraviolet exposure treatment through a mask (film).

[0075] Figure 4 This is a diagram showing the wetting of the hydrophilic and hydrophobic patterned aluminum substrate by water in Example 1 of the present invention.

[0076] Figure 5 This is a contact angle change diagram of the glass sheet after surface oxidation treatment and silane coupling agent treatment in Example 2 of the present invention.

[0077] Figure 6 This is a contact angle diagram of the exposed area and the non-exposed area after the glass sheet substrate treated with a silane coupling agent is subjected to ultraviolet exposure treatment through a mask (film) plate in Example 2 of the present invention.

[0078] Figure 7 This is a wettability diagram of the glass substrate containing the hydrophilic and hydrophobic pattern in Example 2 of the present invention.

[0079] Figure 8 This is a side view of the microchannel reactor in Example 3 of the present invention.

[0080] Fig. 9 1 is a side view of microchannel areas of different sizes in Example 3 of the present invention. Fig.10 This is a process diagram of the liquid flowing in the reactor in Example 5 of the present invention.

[0081] Fig.11 This is a diagram of the flow velocity measurement method in Example 5 of the present invention.

[0082] Fig.12 Schematic diagram of the structure of the non-hydrophilic and hydrophobic patterned substrate microchannel in Comparative Example 1 of the present invention.

[0083] Fig.13 This is a real picture of the linear mask (film) plate in comparative example 2 of the present invention; wherein, the white area is the light-transmitting area, and the other areas are non-light-transmitting areas.

[0084] Fig.14 This is a water wetting diagram of the linear hydrophilic-hydrophobic patterned aluminum sheet substrate in Comparative Example 2 of the present invention.

[0085] Fig.15 This is a process diagram of liquid injection, liquid inflow, and flow in the fluid channel area of ​​the microchannel reactor of the linear hydrophilic-hydrophobic patterned substrate in Comparative Example 2 of the present invention.

[0086] Fig.16 This is a diagram showing the segmentation of deionized water droplets by the hydrophilic and hydrophobic patterned aluminum sheet substrate in Test Example 1 of the present invention after being heated at 120° C. for a period of time.

[0087] Fig.17 It is a schematic diagram of the three-dimensional structure of the reactor in Example 4 of the present invention.

[0088] Fig.18 This is a flow chart for preparing a hydrophilic-hydrophobic patterned substrate as described in Example 1 of the present invention.

[0089] Fig.19 This is a schematic diagram of the planar structure of the reactor in Example 4 of the present invention.

[0090] Fig. 20 This is a top view of the reactor in Example 4 of the present invention.

[0091] Fig.21 It is a schematic diagram of the dimensions of the reactor of the present invention.

[0092] In the figure: 1, first area; 11, first hydrophilic area; 12, hydrophobic area; 2, microchannel area; 21, microwall; 22, fluid channel area; 3, second area; 4, liquid inlet area; 5, liquid injection area; 6, fourth area; 7, fifth area; 8, light-transmitting area; 9, non-light-transmitting area; 10, sixth area; 13, substrate; 14, mask. DETAILED DESCRIPTION

[0093] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0094] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0095] Example 1

[0096] A method for preparing a substrate containing a hydrophilic-hydrophobic pattern is as follows:

[0097] The structure diagram of the molybdenum mask (film) plate 14 in this embodiment 1 is as follows Figure 1As shown, the white area is a light-transmitting area 8, and the other areas are non-light-transmitting areas 9. The mask includes a fourth area 6 and a fifth area 7 arranged side by side, the fourth area 6 and the fifth area 7 are connected, the fourth area 6 includes light-transmitting areas 8 and non-light-transmitting areas 9 arranged in sequence, and the shape of the light-transmitting area 8 is an isosceles trapezoid; the fifth area 7 is a light-transmitting area. The non-light-transmitting area can be covered with cardboard, for example, as long as the area is not light-transmitting.

[0098] As a preferred implementation manner, the molybdenum mask further includes a sixth region 10; the fifth region 7 is located between the fourth region 6 and the sixth region 10, and the sixth region 10 is a second hydrophilic region.

[0099] The aluminum sheet substrate 13 with a size of 2.5×2 cm was immersed in a sodium hydroxide solution with a concentration of 0.5 mol / L, reacted at 30°C for 3 min, and the aluminum sheet was immediately taken out, repeatedly washed with deionized water, immersed in deionized water, heated at 90°C for 30 min, taken out and dried with nitrogen to prepare the substrate 13 after surface oxidation treatment; the contact angle change was measured, and the test results were as follows: Figure 2 ( Figure 2 as shown in the middle figure).

[0100] The aluminum substrate after surface oxidation treatment was modified with 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (PFOS) by chemical vapor deposition method, and the steps are as follows: the aluminum substrate after surface oxidation treatment was laid flat in a vacuum dryer, 3 to 4 drops of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane were dripped into it, and after vacuum treatment for 15 minutes, it was placed in an oven at 80°C and heated for 2 hours, and then taken out for use; the contact angle change was measured, such as Figure 2 ( Figure 2 as shown in the right figure).

[0101] A molybdenum mask 14 is covered on the aluminum sheet treated with a silane coupling agent, wherein the structure of the mask 14 is consistent with the structure of the substrate 13 containing the hydrophilic and hydrophobic pattern, the hydrophilic area in the substrate 13 containing the hydrophilic and hydrophobic pattern corresponds to the light-transmitting area of ​​the mask 14, and the hydrophobic area in the substrate 13 containing the hydrophilic and hydrophobic pattern corresponds to the opaque area of ​​the mask 14; 350W ultraviolet light is irradiated for 8 hours to obtain the aluminum sheet substrate 13 containing the hydrophilic and hydrophobic pattern; the exposure area ( Figure 3 Left) and non-exposed area ( Figure 3 The contact angle of the right side was tested, and the results are as follows Figure 3 2 mL of deionized water was dropped on the aluminum sheet, and then the aluminum sheet was placed at 45° to remove the excess deionized water, and the wetting of the deionized water on the hydrophilic and hydrophobic aluminum sheet substrate was obtained, as shown in Figure 4 As shown. Wherein, the preparation process of the substrate containing hydrophilic and hydrophobic patterns is as follows Fig.18 shown.

[0102] Example 2

[0103] The structural diagram of the molybdenum mask (film) plate in Example 2 is the same as that in Example 1.

[0104] Immerse the glass slide (2cm×2.5cm) in piranha solution (concentrated sulfuric acid and hydrogen peroxide 3:1, v / v) and heat at 125℃ for 1-2h. Take out the glass slide and wash it with deionized water 2-3 times, blow dry with high-purity nitrogen to prepare the substrate after surface oxidation treatment; measure the change of its contact angle, such as Figure 5 ( Figure 5 as shown in the middle figure).

[0105] Place the glass substrate after surface oxidation treatment flat in a vacuum dryer, add 3-4 drops of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane, evacuate for 15 minutes, heat in an oven at 80℃ for 2 hours, take out and set aside; measure the change in contact angle, such as Figure 5 ( Figure 2 The molybdenum mask was covered on the glass sheet treated with silane coupling agent and irradiated with 350W ultraviolet lamp for 8 hours to obtain a glass sheet substrate containing hydrophilic and hydrophobic patterns; the exposed area ( Figure 6 Left) and non-exposed area ( Figure 6 The contact angle of the right side was tested, and the results are as follows Figure 6 2 mL of deionized water was dropped on the aluminum sheet, and then the aluminum sheet was placed at 45° to remove the excess deionized water, and the wetting of the deionized water on the hydrophilic and hydrophobic glass sheet substrate was obtained, as shown in Figure 7 shown.

[0106] Example 3

[0107] Preparation of micro-wall 21 in micro-channel region 2 of micro-channel reactor

[0108] The side view of the microchannel reactor is shown in Figure 8 As shown, the bottom portion refers to a substrate containing a hydrophilic-hydrophobic pattern (i.e., a hydrophilic-hydrophobic patterned substrate). Figure 8In the figure, h is the longest width of the fluid channel area 22, i is the shortest width of the fluid channel area 22, j is the height of the fluid channel area 22, and k is the average width of the micro wall. Take a two-inch single-sided polished silicon wafer, load a blade with a thickness of 25 microns on a dicing machine, set the planned slice depth to 20 microns, and the dicing spacing to 60, 80 or 100 microns, respectively, and divide the polished surface of the two-inch silicon wafer into a groove structure with a depth of 20 microns, a width of 20 microns, and a center spacing of 60, 80 or 100 microns. After the silicon wafer is subjected to plasma surface treatment (air conditions, 200W, 300s), it is placed in a vacuum dryer containing 20 microliters of trifluoromethyltrimethylsilane, evacuated, and kept at 90°C for 30 minutes for hydrophobic treatment to prepare a modified silicon wafer. After taking out the modified silicon wafer, pour 7 grams of mixed liquid with a mass ratio of 1:10 of dimethylsiloxane and curing agent on the surface of the silicon wafer, put it into a vacuum dryer for 10 minutes after leveling, put it into an oven at 90 degrees Celsius for 60 minutes, and then peel off the polydimethylsiloxane (PDMS) from the silicon wafer to obtain a PDMS micro-wall template, which contains a plurality of micro-walls, the height of the micro-wall is 25 microns, the average width k is 20 microns, and the center spacing of adjacent micro-walls 21 is 60 microns, 80 microns or 100 microns. The fluid channel area 22 is between adjacent micro-walls 21.

[0109] Preparation of TiO2 microchannel reactor

[0110] Prepare TiO2 nanoparticles aqueous dispersion (concentration of 10 mg / mL, particle size of 3.5 nm, containing 1 mg / mL sodium dodecyl sulfate SDS), ultrasonicate for 15 min, and set aside. Cut the above PDMS micro-wall template into 0.4 cm×0.4 cm square pieces, that is, the plane area of ​​the microchannel area is 0.4 cm×0.4 cm. After the PDMS micro-wall template is treated with plasma surface (air condition, 30 W, 30 s), take 0.7 microliters of TiO2 aqueous dispersion (10 mg / mL) and drop it on the bottom surface of the microchannel area 2 containing the aluminum sheet substrate after hydrophilic and hydrophobic patterning obtained in Example 1, cover the dispersion with a 0.4 cm×0.4 cm PDMS micro-wall template (make sure that the inlet section of the fluid channel area 22 is flush with the left edge of the microchannel area 2), and place it in a 60°C oven for 10 min. After the water is completely evaporated, a dense nano-catalytic layer with TiO2 catalyst (thickness 0.5-2nm) loaded on three sides of the PDMS micro-wall can be obtained, that is, the surface (left side, right side, and upper side) of the fluid channel area contains a nano-catalyst layer, that is, a TiO2 microchannel reactor composed of a PDMS micro-wall, a TiO2 nanoparticle catalytic layer, and a hydrophilic and hydrophobic patterned substrate is prepared, wherein the longest width h of the fluid channel area 22 is 50, 70, and 90 microns, respectively. Fig. 9 As shown, Fig. 9A side view of a microchannel region containing fluid channel regions of varying widths.

[0111] Example 4

[0112] A hydrophilic and hydrophobic patterned substrate circulation microchannel reactor, such as Fig. 20 As shown, the reactor comprises a first region 1 and a microchannel region 2 arranged side by side, and the first region 1 and the microchannel region 2 are connected;

[0113] The first region 1 comprises a first hydrophilic region 11 and a hydrophobic region 12 which are arranged in sequence and at intervals; along the direction of liquid flow, the first hydrophilic region 11 has a trapezoidal structure;

[0114] The microchannel area 2 includes microwalls 21 and a fluid channel area 22 that are arranged in sequence. The first hydrophilic area 11 and the hydrophobic area 12 are both connected to the fluid channel area 22. A nanocatalyst layer is also provided on the surface of the fluid channel area 22. The nanocatalyst is TiO2 nanoparticles, and the thickness of the nanocatalyst layer is 0.5-2nm.

[0115] When the liquid flows through the first region 1 and the microchannel region 2, it is in a circular flow.

[0116] The center spacing between adjacent micro-walls is 60 microns, 80 microns or 100 microns. The average width k of each micro-wall is the same, which is 20 microns. The height of the micro-wall is 25 microns.

[0117] Wherein, the material of the micro-wall has the meaning as described in the above embodiment 3.

[0118] The material of the first hydrophilic region 11 and the material of the hydrophobic region 21 both have the above meanings.

[0119] As a preferred embodiment of the present application, the reactor further comprises a second region 3, the microchannel region 2 is located between the first region 1 and the second region 3, and the second region 3 is a second hydrophilic region.

[0120] The material of the second hydrophilic area is the same as that of the first hydrophilic area 11 .

[0121] In this embodiment, the fluid channel area 22 is formed between adjacent micro-walls 21 .

[0122] As another preferred embodiment of the present invention, Fig.19 As shown, the first region 1 includes a liquid inlet region 4 and a liquid injection region 5; the liquid inlet region 4 is used for liquid to enter the reactor. The liquid injection region 4 and the liquid inlet region 5 are arranged side by side, and the liquid inlet region 4 is close to the microchannel region 2; the liquid inlet region 4 and the liquid injection region 5 together form the first region 1.

[0123] The liquid inlet area 4 includes a first hydrophilic area 11 and a hydrophobic area 12 which are arranged in sequence and at intervals.

[0124] The liquid injection area 5 includes a first hydrophilic area 11 and a hydrophobic area 12 which are arranged in sequence and at intervals.

[0125] Example 5

[0126] A 1 mg / mL green fluorescent microsphere (particle size 500 nm) aqueous solution was prepared for use. The microchannel reactors with fluid channel areas of 50, 70, and 90 micrometers in width were prepared by the method of Example 3. 0.5-1 microliter of 1 mg / mL green fluorescent microsphere (particle size 500 nm) aqueous solution was dripped into the channel opening of the reactor respectively from one end of the injection area, and the reactor was observed and photographed under a fluorescence microscope. The results are as follows: Fig.10 As shown, a droplet is dripped into the injection area 5, and when the droplet contacts the liquid inlet area, the droplet spreads along the first hydrophilic area 11 to form a triangular micro-droplet; when the droplet contacts the entrance of the fluid channel area 22, it quickly flows into the fluid channel area 22 under the action of capillary force. When the fluid channel area 22 connected to the first hydrophilic area 11 is filled with liquid, the Laplace pressure generated by the curved liquid surface of the micro-droplet continues to push the liquid forward, and liquid continuously flows out of the outlet of the fluid channel area 22. When the outflowing liquid contacts the empty fluid channel areas 22 corresponding to the hydrophobic areas on both sides, it flows back again under the action of capillary force. After filling the fluid channel area 22, the outflowing liquid flows from the hydrophobic area with low adhesion to the hydrophilic area with high adhesion, forming a reflux cycle. As shown Fig. 20 As shown, in the fluid channel area connected to the first hydrophilic area, the liquid flows in the positive direction, and in the fluid channel area connected to the hydrophobic area, the liquid flows in the negative direction.

[0127] When all the fluid channel areas are filled with liquid, the fluid flow rates of the fluid channel areas 22 with widths of 50, 70, and 90 microns in the microchannel reactor are measured respectively, and the flow rates are calculated based on the particle movement. The test method is as follows: Fig.11 The timing starts from the random position of the fluorescent microsphere in the fluid channel area and ends at any position in the fluid channel area. The test results are shown in Table 1. By comparison, it can be seen that the narrower the width of the fluid channel area 22, the faster the flow rate (the flow rate is fastest in the 50 micron fluid channel area).

[0128] Table 1 Flow rate measurement data in different fluid channel areas in Example 5

[0129]

[0130]

[0131] Comparative Example 1

[0132] The difference between the microchannel reactor of Comparative Example 1 and the TiO2 microchannel reactor of Example 3 is that the substrate of Comparative Example 1 is a fully hydrophilic non-patterned aluminum sheet substrate; the rest of the structure is the same as the TiO2 microchannel reactor of Example 3.

[0133] The preparation method of the fully hydrophilic non-patterned aluminum sheet substrate is the same as the preparation method of the substrate containing hydrophilic and hydrophobic patterns described in Example 1, except that the mask used in the fully hydrophilic non-patterned aluminum sheet substrate is a mask of a fully light-transmitting area.

[0134] The microchannel reactor of Comparative Example 1 was prepared according to the TiO2 microchannel reactor method of Example 3 (the widths of the fluid channel regions were 50, 70, and 90 microns, respectively). Fig.12 As shown, Fig.12 In the embodiment, the substrate is a fully hydrophilic non-patterned aluminum sheet substrate.

[0135] The flow rate is measured by the method of Example 5, and the test results are shown in Table 2. By comparison, it can be seen that in the hydrophilic and hydrophobic patterned substrate circulation microchannel reactor of the present application, the fluid flow rate is significantly higher than the microchannel reactor of the non-hydrophilic and hydrophobic pattern in Comparative Example 1, and the flow rates in the channels of 50, 70, and 90 microns are increased by 4.3, 4.6, and 2.5 times, respectively. The segmentation of the droplets by the hydrophilic and hydrophobic pattern substrate effectively increases the flow rate in the channel. This is because in the hydrophilic and hydrophobic patterned circulation microchannel reactor, the droplets are spread only on the micro first hydrophilic area before entering the fluid channel area, forming a curved liquid surface with a smaller radius of curvature of the micro droplets, which produces a larger Laplace pressure to push the liquid forward. In the microchannel reactor of the non-hydrophobic and hydrophobic patterned substrate, the droplets are freely spread before entering the microchannel, the liquid surface has a large radius of curvature, and the Laplace pressure is small. The liquid flow is driven mainly by the evaporation of the liquid at the outlet, so the flow rate is relatively small.

[0136] Table 2 Flow rate measurement data in different fluid channel areas in Comparative Example 1

[0137] Channel width (μm) <![CDATA[Flow velocity (μm s -1 )]]> 50 534 70 394 90 285

[0138] Comparative Example 2

[0139] The method for preparing a substrate containing a hydrophilic and hydrophobic pattern is as described in Example 1, except that a linear mask (film) plate (such as Fig.13 As shown in FIG. 2 , each first hydrophilic region in Comparative Example 2 has a rectangular cross section. A linear hydrophilic-hydrophobic patterned aluminum substrate is obtained, and the infiltration of deionized water thereon is shown in FIG. Fig.14 shown.

[0140] A linear hydrophilic-hydrophobic patterned substrate microchannel reactor was prepared according to the method of Example 3, and a liquid flow behavior test was performed on the linear hydrophilic-hydrophobic patterned substrate microchannel reactor according to the method of Example 5. The test process is as follows: Fig.15 As shown, when the droplet is in the stripe-shaped hydrophilic pattern area, there is no driving force to drive the droplet to move to the right into the microchannel.

[0141] Test Example 1

[0142] The aluminum sheet substrate containing the hydrophilic and hydrophobic pattern in Example 1 was subjected to a heat resistance test.

[0143] The hydrophilic and hydrophobic patterned aluminum substrate obtained in Example 1 was placed on a hot plate and heated. The contact angle of the hydrophilic area was measured every 15 minutes to observe the change in the substrate wettability during the heating process and test its heat resistance. During the heating process, the hydrophilicity of the exposed area of ​​the aluminum sheet was lost to a certain extent, but the aluminum sheet substrate remained relatively hydrophilic when heated at 120°C and 160°C for 60 minutes, and the wettability was greatly different from that of the unexposed area, and the droplets could still be split. The results are shown in Figure 2. Fig.16 As shown in Table 3. The hydrophilic-hydrophobic patterned aluminum substrate has good heat resistance.

[0144] Table 3 Changes in contact angle of the hydrophilic area during heating of the hydrophilic and hydrophobic patterned aluminum sheet in Test Example 1

[0145]

[0146] The above is an explanation of the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hydrophilic and hydrophobic patterned substrate circulation microchannel reactor, characterized in that: The reactor comprises a first region and a microchannel region disposed side by side, wherein the first region and the microchannel region are in communication; The first region includes a first hydrophilic region and a hydrophobic region that are sequentially spaced apart; along the liquid flow direction, the size of the first hydrophilic region gradually decreases; The microchannel area includes microwalls and a fluid channel area that are sequentially spaced apart, and the first hydrophilic area and the hydrophobic area are both connected to the fluid channel area; a nano catalyst layer and / or a biological enzyme is also provided on the surface of the fluid channel area; When the liquid circulates in the first region and the microchannel region, it is in a circular flow shape; The reactor further comprises a second region, the microchannel region is located between the first region and the second region, and the second region is a second hydrophilic region.

2. The microchannel reactor according to claim 1, characterized in that: The first hydrophilic area is in a trapezoidal shape.

3. The microchannel reactor according to claim 1, characterized in that: The first region includes at least one liquid inlet area; the liquid inlet area includes a first hydrophilic area and a hydrophobic area which are sequentially arranged at intervals.

4. The microchannel reactor according to claim 3, characterized in that: The first region further comprises a liquid injection area, which is arranged side by side with the liquid inlet area and is close to the microchannel area; the liquid injection area comprises a first hydrophilic area and a hydrophobic area which are arranged in sequence and at intervals.

5. The microchannel reactor according to claim 4, characterized in that: The liquid inlet area and the liquid injection area together form the first region.

6. The microchannel reactor according to claim 1, characterized in that: The thickness of the nano catalyst layer and / or biological enzyme is 0.5-5 microns.

7. The microchannel reactor according to claim 1, characterized in that The particle size of the nanocatalyst is 2nm to 900nm; the nanocatalyst is selected from one or more of colloidal microspheres, nanoparticles, carbon nanotubes, and graphene; or selected from one or more of a core-shell structure with PS nanomicrospheres or inorganic nanospheres as cores and a platinum shell, gold shell, silver shell, copper shell, DNA molecule, organic fluorescent molecule, functional organic small molecule or functional polymer as the outer surface of the core; The enzyme is selected from one or more of lipase CAL-b, trypsin, sucrose phosphorylase, aminoacylase, glucose isomerase, manganese peroxidase, laccase, ribulose-1,5-bisphosphate carboxylase, α-amylase, urease and cellulase.

8. The microchannel reactor according to claim 1, characterized in that: The material of the bottom surface of the microchannel area is the same as or different from the material of the first hydrophilic area, and both are selected from hydrophilic materials; the material of the hydrophobic area is a hydrophobic material; The hydrophilic material is a hydrophilic group grafted on the surface of the substrate; the hydrophilic group is a sulfonic acid group, a sulfate group, a phosphoric acid group, a carboxylic acid group, an amino group, a quaternary ammonium group, or a carboxylate; The hydrophobic material is a hydrophobic group grafted on the surface of the substrate, and the hydrophobic group is C 1-20 alkyl.

9. The microchannel reactor according to claim 1, characterized in that: The material of the micro wall is at least one of polydimethylsiloxane, copolyester, polyvinyl alcohol, polycarbonate, polyvinyl chloride, cellulose acetate, ethyl cellulose, vinyl alcohol-vinyl acetate, ethylene-propylene polymer and sodium alginate.

10. The microchannel reactor according to claim 1, characterized in that: The fluid channel area is formed between adjacent micro walls.

11. The microchannel reactor according to claim 10, characterized in that: The fluid channel area is formed by seamlessly combining a substrate and a plurality of micro walls.

12. The microchannel reactor according to claim 11, characterized in that: The substrate is one or more materials of silicon and metal. The silicon is a glass sheet, a single crystal silicon sheet, a silicon dioxide sheet, a quartz sheet or a polydimethylsiloxane film. The metal is an aluminum sheet, a copper sheet, a nickel sheet or an aluminum oxide sheet.

13. The method for preparing a microchannel reactor according to any one of claims 1 to 12, characterized in that: The method comprises the following steps: (1) preparing a substrate containing a hydrophilic-hydrophobic pattern, wherein the substrate containing a hydrophilic-hydrophobic pattern comprises a bottom surface of the microchannel region, a first hydrophilic region, and a hydrophobic region; (2) preparing a micro-wall on the bottom surface of the micro-channel area in step (1), so that the micro-channel area is sequentially provided with micro-walls and fluid channel areas, and then preparing a nano-catalyst layer and / or biological enzyme on the surface of the fluid channel area to prepare a micro-channel reactor.

14. The preparation method according to claim 13, characterized in that: In step (1), the substrate containing the hydrophilic and hydrophobic pattern further includes a bottom surface of the second region.

15. The preparation method according to claim 13, characterized in that: In step (1), before modification, the substrate is oxidized using an acidic solution or an alkaline solution.

16. The preparation method according to claim 13, characterized in that: In step (1), the specific preparation steps of the substrate containing hydrophilic and hydrophobic patterns are as follows: after the substrate after surface oxidation treatment is reacted with a silane coupling agent, a mask is covered on the substrate, and ultraviolet light is irradiated on the mask to prepare the substrate containing hydrophilic and hydrophobic patterns; wherein the structure of the mask is consistent with the structure of the substrate containing hydrophilic and hydrophobic patterns, the hydrophilic area of ​​the substrate containing hydrophilic and hydrophobic patterns corresponds to the light-transmitting area of ​​the mask, and the hydrophobic area of ​​the substrate containing hydrophilic and hydrophobic patterns corresponds to the light-opaque area of ​​the mask.

17. The preparation method according to claim 16, characterized in that: The mask plate includes a fourth area and a fifth area arranged side by side, the fourth area and the fifth area are connected, the fourth area includes a light-transmitting area and a non-light-transmitting area arranged in sequence at intervals, and the cross-section of the light-transmitting area is an isosceles trapezoid; the fifth area is a light-transmitting area.

18. The preparation method according to claim 17, characterized in that: The mask also includes a sixth region; the fifth region is located between the fourth region and the sixth region, and the sixth region is a second hydrophilic region.

19. The preparation method according to claim 13, characterized in that: In step (2), a nano catalyst layer and / or biological enzyme is attached to the surface of the fluid channel region using micro-nano self-assembly technology or enzyme immobilization method.

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