Preparation method of photonic crystal microbeads with inverse opal structures
By controlling the flow rate in the microfluidic chip to generate microbeads and forming an anti-opal structure during drying and calcining, the problem of long forming time, high cost and poor quality of photonic crystal microbeads is solved, and rapid, economical and high-quality photonic crystal microbead preparation is achieved, and magnetic responsiveness and optical properties are introduced.
Patent Information
- Application Number
- CN202311460915.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-03
- Publication Date
- 2025-05-06
AI Technical Summary
The existing preparation methods for photonic crystal microbeads have problems such as long forming time, high cost, uneven quality and low mechanical strength, making it difficult to quickly and economically obtain high-quality photonic crystal microbeads.
By controlling the flow rate of the aqueous and oily solutions in the microfluidic chip, the oily solution is cut from the aqueous solution to form microbeads, and the anti-opal structure photonic crystal microbeads are formed during drying and calcining.
The rapid molding of photonic crystal microbeads is achieved, with low cost and high quality, and magnetic responsiveness and optical properties are introduced, which eliminates crack problems and improves mechanical strength.
Smart Images
Figure CN119932689A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of photonic crystals, and in particular relates to a method for preparing anti-protein structure photonic crystal microbeads. Background Art
[0002] Photonic crystals are structures with two media of different refractive indices arranged periodically. Photonic crystals have a bandgap and can modulate electromagnetic waves with a response wavelength, selectively allowing light of a certain wavelength to pass through while blocking light of other wavelengths. Incorporating black particles during the self-assembly process of photonic crystals can form a short-range orderly arrangement of colloidal particles, reduce the scattering of incoherent light on the surface of the photonic crystal, thereby improving color saturation and making color resolution clearer.
[0003] Natural photonic crystals are often irregular in shape, which limits their application. At present, artificial photonic crystals are usually prepared by micro-machining methods such as "top-down" lithography and "bottom-up" self-assembly methods. "Top-down" methods such as lithography, electron beam etching, holography and sacrificial template method all require expensive high dielectric constant materials, and the process is relatively complicated, which increases the cost of obtaining completely bandgap photonic crystals. Among the common self-assembly preparation methods, the methods represented by the pulling method, spin coating method, gravity method and natural evaporation method are difficult to evaporate the solvent quickly, and the prepared photonic crystals take a long time to form, which generally takes more than a few days. In addition, during the preparation process, this type of method is easily affected by factors such as ambient temperature, humidity, and colloid concentration. Under long forming cycles and high calcination temperatures, photonic crystal microbeads often have uneven quality, low mechanical strength, and are usually prone to cracks on the surface; self-assembly methods such as centrifugation and electrophoretic deposition can shorten the forming time, but they require additional driving force, and the preparation system is often relatively complex. Therefore, developing a method for preparing photonic crystal microbeads with high forming quality, fast speed and low cost is a major challenge in this field. Summary of the invention
[0004] The purpose of the present invention is to overcome the shortcomings and deficiencies in the prior art, provide a method for preparing anti-protein structure photonic crystal microbeads, introduce the magnetic material of ferroferric oxide and the optical properties of polystyrene opal structure into the system, and synthesize an anti-protein structure photonic crystal microbead with magnetic responsiveness, fluorescence properties and other characteristics.
[0005] The present invention is achieved through the following technical solutions:
[0006] Polystyrene microspheres with a particle size of 200-300nm are configured with a first solvent to form a polystyrene emulsion; nano-ferroferric oxide is configured with a second solvent to form a ferroferric oxide dispersion; the polystyrene emulsion and the ferroferric oxide dispersion are mixed to obtain an aqueous solution; the aqueous solution and the oily solution are respectively injected into different pipes in a microfluidic chip, and the aqueous solution and the oily solution are collected at their respective pipe outlets; wherein the flow rates of the aqueous solution and the oily solution are respectively adjusted in different pipes, so that the aqueous solution and the oily solution are collected at their respective pipe outlets, and then the oily solution cuts the aqueous solution to generate microbeads; the oily solution is silicone oil; the microbeads and the oily solution enter a microbead generation channel together, and a microbead mixture is collected at the outlet of the microbead generation channel; the microbead mixture is dried to remove moisture to obtain solid microbeads; the solid microbeads are calcined to remove polystyrene to obtain inverse opal structure photonic crystal microbeads.
[0007] In the present invention, the flow rate of the aqueous solution and the oily solution is controlled in different channels of the microfluidic chip, and the oily solution is used to cut the aqueous solution at the convergence point to obtain microbeads of appropriate particle size, and silicone oil and microbeads are present in the collected large-scale microbead mixture, and polystyrene is self-assembled to form an opal structure during the drying of the microbeads, and nano-iron tetroxide is filled in the gap of the opal structure, and then calcined to remove polystyrene, and the remaining nano-iron tetroxide forms an inverse opal structure photonic crystal microbead. The preparation method of the inverse opal structure photonic crystal microbead of the present invention is low in cost, easy to operate, mild in reaction conditions, and high in molding quality. The prepared inverse opal structure photonic crystal can meet the required design particle size and is uniform in size, eliminating the cracks generated by the processes such as template drying and long-term calcination, and is conducive to improving mechanical strength while removing polystyrene by calcination, and the magnetic responsiveness of ferroferric oxide and the optical properties of the opal structure are introduced, and the structural color is bright and obvious, and has certain functionality.
[0008] Further, in different pipelines, the flow rates of the aqueous solution and the oil-phase solution are adjusted respectively, so that the aqueous solution and the oil-phase solution are converged at the outlets of their respective pipelines, and in the step of the oil-phase solution cutting the aqueous solution to generate microbeads, the flow rate of the aqueous solution is 2-20 μL / min, the flow rate of the oil-phase solution is 1.5-3 mL / h, and the flow directions of the aqueous solution and the oil-phase solution are perpendicular. The aqueous solution and the oil-phase solution converge at the outlets of their respective pipelines, and by adjusting the flow rates of the aqueous solution and the oil-phase solution and controlling the flow direction, the oil-phase solution cuts the aqueous solution at the convergence point to form microbeads that meet the designed particle size, thereby obtaining a microbead mixture in which the microbeads and the oil-phase solution are mixed.
[0009] Furthermore, in the step of configuring polystyrene microspheres with a particle size of 200-300 nm with a first solvent to form a polystyrene emulsion, the first solvent is deionized water, and the concentration of the polystyrene emulsion is 5-50wt%; in the step of configuring nano-ferroferric oxide with a second solvent to form a ferroferric oxide dispersion, the second solvent is deionized water, and the concentration of the ferroferric oxide dispersion is 2.5-10wt%. The concentrations of the polystyrene emulsion and the ferroferric oxide dispersion are controlled to form an inverse opal structure photonic crystal.
[0010] Furthermore, in the step of mixing the polystyrene emulsion with the ferroferric oxide dispersion to obtain an aqueous solution, the volume percentage of the polystyrene emulsion to the ferroferric oxide dispersion is 5:1-7:1. The mixing ratio in the aqueous solution is controlled so that the ferroferric oxide is filled in the opal structure of the polystyrene in the subsequent self-assembly process.
[0011] Furthermore, in the step of drying the microbead mixture to remove water and obtain solid microbeads, the microbead mixture is evaporated and dried at 60-70°C to remove water, and the polystyrene self-assembles to form an opal structure, and the nano-iron tetroxide fills the gaps in the opal structure. In the process of drying the water, the polystyrene self-assembles to form an opal structure with an ordered lattice, and the nano-iron tetroxide particles fill the gaps in the opal structure, and the temperature is controlled to evaporate the water while promoting the reaction.
[0012] Furthermore, in the step of calcining the solid microbeads to remove polystyrene and obtain inverse opal structure photonic crystal microbeads, the solid microbeads are calcined at 400-500° C. for 6 hours to remove polystyrene. The polystyrene with the opal structure is removed by calcination, and the remaining nano-iron tetroxide forms an inverse opal structure.
[0013] Furthermore, after the step of obtaining the inverse opal structure photonic crystal microbeads, the inverse opal structure photonic crystal microbeads are soaked in n-ethane to remove the silicone oil in the inverse opal structure photonic crystal microbeads and improve the purity.
[0014] Furthermore, the particle size of the nano-iron tetroxide is 20-50 nm. The particle size of the nano-iron tetroxide is controlled to form inverse opal structure photonic crystal micro beads with photonic crystal properties.
[0015] Furthermore, the inner diameter of the microbead generation channel is 200 μm. The inner diameter of the microbead generation channel is controlled to control the particle size of the formed microbeads.
[0016] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is a schematic diagram of the internal structure of a microfluidic chip.
[0018] Figure 2 This is a microscope image of an inverse opal structured photonic crystal bead.
[0019] Figure 3 This is the ultraviolet absorption spectrum of polystyrene at 310nm. DETAILED DESCRIPTION
[0020] The present invention provides a method for preparing an inverse opal structure photonic crystal microbead, comprising the following steps:
[0021] Step S1: polystyrene microspheres with a particle size of 200-300 nm are mixed with a first solvent to form a polystyrene emulsion; nano-ferroferric oxide is mixed with a second solvent to form a ferroferric oxide dispersion;
[0022] Step S2: mixing the polystyrene emulsion with the ferroferric oxide dispersion to obtain an aqueous solution;
[0023] Step S3: injecting the aqueous solution and the oily solution into different channels in the microfluidic chip respectively, and the aqueous solution and the oily solution are collected at the outlets of their respective channels; wherein the flow rates of the aqueous solution and the oily solution are adjusted in the different channels respectively, so that after the aqueous solution and the oily solution are collected at the outlets of their respective channels, the oily solution cuts the aqueous solution to form microbeads; and the oily solution is silicone oil;
[0024] The microbeads and the oil phase solution enter the microbead generation channel together, and the microbead mixed solution is collected at the outlet of the microbead generation channel;
[0025] Step S4: drying the microbead mixture to remove moisture and obtain solid microbeads;
[0026] Step S5: calcining the solid microbeads to remove polystyrene and obtain inverse opal structured photonic crystal microbeads.
[0027] In the present invention, the flow rate of the aqueous solution and the oily solution is controlled in different channels of the microfluidic chip, the oily solution is used to cut the aqueous solution at the convergence to obtain microbeads of appropriate particle size, silicone oil and microbeads are present in the collected microbead mixture, polystyrene self-assembles to form an opal structure during the process of drying the microbeads, nano-iron tetroxide is filled in the gap of the opal structure, and then calcined to remove polystyrene, and the remaining nano-iron tetroxide forms an inverse opal structure photonic crystal microbead. The preparation method of the inverse opal structure photonic crystal microbead of the present invention is low in cost, easy to operate, and mild in reaction conditions. The prepared inverse opal structure photonic crystal can meet the required design particle size and is uniform in size, eliminating the cracks generated by the processes such as template drying and long-term calcination, and calcining is beneficial to improving mechanical strength while removing polystyrene, and the magnetic responsiveness of ferroferric oxide and the optical properties of the opal structure are introduced, and the opal structure of polystyrene presents a red structural color, and the structural color is bright and obvious, and has certain functionality. The inverse opal structure photonic crystal prepared by the present invention has the characteristics of magnetic responsiveness and fluorescence performance, and can be applied to the fields of optical encoding, adsorption, detection and analysis, and compared with the photonic crystals of ordinary structure, it has a significantly increased specific surface area and empty island structure, which is conducive to the application in research on adsorption and the like, and the magnetic responsiveness and bright structural color are also conducive to convenient recovery after use.
[0028] In step S1, the first solvent is deionized water, the concentration of the polystyrene emulsion is 5-50wt%; the particle size of the nano-ferroferric oxide is 20-50nm, the second solvent is deionized water, and the concentration of the ferroferric oxide dispersion is 2.5-10wt%. The concentrations of the polystyrene emulsion and the ferroferric oxide dispersion are controlled to form an inverse opal structure photonic crystal. The particle size of the nano-ferroferric oxide is controlled to form an inverse opal structure photonic crystal microbead with photonic crystal properties.
[0029] Polystyrene can be prepared by soap-free emulsion polymerization: add water and sodium dodecyl sulfate into a container, introduce N2, heat to 60°C, add methyl methacrylate and acrylic acid, and stir; add styrene and heat to 80°C, add potassium persulfate, and continue the reaction until red polystyrene microspheres are obtained.
[0030] In step S2, in the step of mixing the polystyrene emulsion with the ferroferric oxide dispersion to obtain an aqueous solution, the volume percentage of the polystyrene emulsion to the ferroferric oxide dispersion is 5:1-7:1. The mixing ratio in the aqueous solution is controlled so that the ferroferric oxide is filled in the opal structure of the polystyrene in the subsequent self-assembly process.
[0031] In step S3, the flow rate of the aqueous solution is 2 μL / min, the flow rate of the oil solution is 1.5 mL / h, and the flow directions of the aqueous solution and the oil solution are perpendicular. The aqueous solution and the oil solution converge at their respective pipeline outlets. By adjusting the flow rates of the aqueous solution and the oil solution and controlling the flow direction, the oil solution cuts the aqueous solution at the convergence point to form microbeads that meet the designed particle size, and obtains a microbead mixture in which the microbeads and the oil solution are mixed. The inner diameter of the microbead generation channel is 200 μm. The inner diameter of the microbead generation channel is controlled to control the particle size of the microbeads formed.
[0032] In step S4, the microbead mixture is evaporated and dried at 60-70°C to remove water, and the polystyrene self-assembles to form an opal structure, and the nano-iron tetroxide particles are filled in the gaps of the opal structure. In the process of drying the water, the polystyrene self-assembles to form an opal structure with an ordered lattice, and the nano-iron tetroxide particles are filled in the gaps of the opal structure. The temperature is controlled to evaporate the water while promoting the reaction.
[0033] In step S5, the solid microbeads are calcined at 400-500° C. for 6 hours to remove polystyrene. The polystyrene with the opal structure is removed by calcination, and the remaining nano-iron tetroxide forms an inverse opal structure.
[0034] The method for preparing inverse opal structure photonic crystal microbeads further comprises step S6: soaking the inverse opal structure photonic crystal microbeads with n-hexane to remove silicone oil in the inverse opal structure photonic crystal microbeads through soaking to improve the purity.
[0035] Example 1
[0036] This embodiment provides a method for preparing an inverse opal structure photonic crystal microbead, comprising the following steps:
[0037] Step S1, polystyrene microspheres with a particle size of 200-300 nm and a first solvent are mixed to form a polystyrene emulsion; nano-ferroferric oxide and a second solvent are mixed to form a ferroferric oxide dispersion. The specific operations are as follows:
[0038] Polystyrene microspheres were prepared by soap-free emulsion polymerization. 80 mL of water and 0.008 g of sodium dodecyl sulfate were added to a three-necked flask, N2 was introduced, a stirring bar was added, 1 g of methyl methacrylate and 1 g of acrylic acid were added after heating to 60 °C, 15 g of styrene was added after the reaction was continued for 10 min, the temperature was raised to 80 °C, 0.15 g of potassium persulfate was added, and the reaction was continued for 10 h to obtain red polystyrene microspheres with a particle size of 310 nm.
[0039] 4.72 g of polystyrene microspheres were added to 70 mL of deionized water, stirred for 10 min, and ultrasonicated for 5 min to obtain a 6.7 wt% polystyrene microsphere emulsion;
[0040] 2.5 g of nano-ferroferric oxide was added into 70 mL of deionized water, stirred for 10 min, and ultrasonicated for 5 min to obtain a 3.6 wt % nano-ferroferric oxide dispersion.
[0041] Step S2, mixing the polystyrene emulsion with the ferroferric oxide dispersion to obtain an aqueous solution, the specific operation is as follows:
[0042] 10mL polystyrene microsphere emulsion and 2mL nano ferroferric oxide dispersion were mixed, and ultrasonicated for 5min to obtain an aqueous solution. The aqueous solution contained polystyrene microspheres, nano ferroferric oxide and deionized water. It is understandable that the polystyrene microsphere emulsion and the nano ferroferric oxide dispersion can be mixed in a ratio of 5:1 by volume percentage.
[0043] Step S3, injecting the aqueous solution and the oil solution into different pipes in the microfluidic chip respectively, and the aqueous solution and the oil solution are collected at the outlets of their respective pipes; wherein, the flow rates of the aqueous solution and the oil solution are adjusted in different pipes respectively, so that after the aqueous solution and the oil solution are collected at the outlets of their respective pipes, the oil solution cuts the aqueous solution to generate microbeads; the microbeads and the oil solution enter the microbead generation channel together, and the microbead mixture is collected at the outlet of the microbead generation channel; the oil solution is silicone oil. The specific operation is:
[0044] The aqueous solution and the oil solution obtained in step S2 are respectively injected into different channels in the microfluidic chip, and the flow rate of the aqueous solution is adjusted to 2 μL / min, and the flow rate of the oil solution is adjusted to 1.5 mL / h. The flow directions of the aqueous solution and the oil solution are perpendicular. At the confluence, the aqueous solution is cut by the oil solution to form microbeads of uniform size of about 200 μm, and enters the microbead generation channel together with the oil solution;
[0045] Figure 1 is a schematic diagram of the internal structure of the microfluidic chip. In this embodiment, please refer to Figure 1 The microfluidic chip includes a first pipeline 1, a second pipeline 2, a third pipeline 3 and a microbead generation pipeline 4 which are arranged in parallel in sequence. The first pipeline 1, the second pipeline 2 and the third pipeline 3 are connected at their respective outlets, and a convergence is formed at the outlet of the second pipeline 2, and the microbead generation pipeline 4 is connected to the convergence. The inner diameters of the first pipeline 1 and the third pipeline 3 are 300 μm, the inner diameter of the second pipeline 2 is 20 μm, and the inner diameter of the microbead generation pipeline 4 is 300 μm-1 mm, and its inner diameter gradually increases along the outlet direction.
[0046] Among them, the first pipeline 1 and the third pipeline 3 are oil phase solution pipelines, and the second pipeline 2 is an aqueous phase solution pipeline. Under the action of gas pressure, the aqueous phase solution and the oil phase solution flow to the converging point and are squeezed into the microbead generation pipeline 4. In this process, since the flow speed of the oil phase solution is much higher than that of the aqueous phase solution and the flow direction is vertical, the aqueous phase solution is continuously cut by the oil phase solution to form a microbead structure. The microbeads and the oil phase solution are squeezed into the microbead generation pipeline 4 together to form an "oil-in-water" structure to obtain a microbead mixture. A collection container filled with silicone oil is provided at the outlet of the microbead generation pipeline 4, and the microbead mixture enters the collection container.
[0047] Step S4, drying the microbead mixture to remove moisture and obtain solid microbeads, specifically: evaporating the microbead mixture at 60-70°C for 48h, drying to remove moisture, polystyrene self-assembles to form an opal structure, and nano-iron tetroxide fills the gaps in the opal structure. In the process of drying the moisture, polystyrene self-assembles to form an opal structure of an ordered lattice, and nano-iron tetroxide particles fill the gaps in the opal structure, and the temperature is controlled to evaporate the moisture while promoting the reaction. The solid microbead size obtained after evaporation is 50-150μm.
[0048] Step S5, calcining the solid microbeads to remove polystyrene and obtain inverse opal structure photonic crystal microbeads, specifically, slowly heating the solid microbeads to 500°C and calcining for 6 hours to remove polystyrene and leave nano-iron tetroxide. The polystyrene with opal structure is removed by calcination, and the remaining nano-iron tetroxide forms an inverse opal structure.
[0049] Step S6, soaking the inverse opal structure photonic crystal microbeads with n-hexane, specifically, the following operations: since in step S5, the nano-iron tetroxide is soaked in a collection container filled with silicone oil, the nano-iron tetroxide with the inverse opal structure is moved into the soaking container, soaked with n-hexane, the silicone oil between the gaps of the nano-iron tetroxide with the inverse opal structure is removed, and the n-hexane is replaced multiple times to obtain the inverse opal structure photonic crystal microbeads. Due to the volatility of n-hexane, this process often produces a large amount of water vapor, so it must be operated in a certain dry and constant temperature environment, otherwise it will affect the assembly.
[0050] Figure 2 For a microscope image of an inverse opal structured photonic crystal microbead, see Figure 2 The size of the prepared inverse opal structured photonic crystal microbeads is 122.21 μm. Figure 3 This is the UV absorption spectrum of polystyrene at 310nm, please refer to Figure 3The particle size of the polystyrene prepared in this case is 310nm, and the ultraviolet absorption peak is located at 610-720nm, that is, the red light in the visible light region, which means that the opal structure formed by the polystyrene in step S4 has the optical property of red structural color. In step S5, the solid microbeads are calcined to remove the polystyrene, and the remaining nano-iron tetroxide forms an inverse opal structure, while the original opal structure is formed by holes. The prepared inverse opal structure photonic crystal has the characteristics of magnetic responsiveness and fluorescence performance, and can be applied to optical coding, adsorption, detection and analysis and other fields.
[0051] Example 2
[0052] This embodiment 2 provides a method for preparing inverse opal structure photonic crystal microbeads, the main steps of which are the same as those of embodiment 1, and the main difference from embodiment 1 is that:
[0053] Step S1, polystyrene microspheres with a particle size of 200-300nm are mixed with a first solvent to form a polystyrene emulsion, the first solvent is deionized water, and the concentration of the polystyrene emulsion is 5wt%; nano-ferroferric oxide is mixed with a second solvent to form a ferroferric oxide dispersion, the second solvent is deionized water, and the concentration of the ferroferric oxide dispersion is 2.5wt%.
[0054] In step S2, the polystyrene emulsion is mixed with the ferroferric oxide dispersion to obtain an aqueous solution, wherein the polystyrene microsphere emulsion and the nano ferroferric oxide dispersion are mixed in a ratio of 5:1 by volume.
[0055] Step S3, adjusting the flow rates of the aqueous solution and the oil phase solution in different pipelines respectively, so that the aqueous solution and the oil phase solution are combined at their respective pipeline outlets, and then the oil phase solution cuts the aqueous solution to generate microbeads, the flow rate of the aqueous solution is 2 μL / min, and the flow rate of the oil phase solution is 1.5 mL / h.
[0056] Example 3
[0057] This embodiment 3 provides a method for preparing inverse opal structure photonic crystal microbeads, the main steps of which are the same as those of embodiment 1, and the main difference from embodiment 1 is that:
[0058] Step S1, polystyrene microspheres with a particle size of 200-300nm are mixed with a first solvent to form a polystyrene emulsion, the first solvent is deionized water, and the concentration of the polystyrene emulsion is 50wt%; nano-ferroferric oxide is mixed with a second solvent to form a ferroferric oxide dispersion, the second solvent is deionized water, and the concentration of the ferroferric oxide dispersion is 10wt%.
[0059] Step S3, adjusting the flow rates of the aqueous solution and the oil solution in different pipelines respectively, so that the aqueous solution and the oil solution are combined at their respective pipeline outlets, and then the oil solution cuts the aqueous solution to form microbeads, the flow rate of the aqueous solution is 20 μL / min, and the flow rate of the oil solution is 3 mL / h.
[0060] The flow rates of the aqueous solution and the oil solution were adjusted in different pipelines respectively, so that the aqueous solution and the oil solution were combined at their respective pipeline outlets. In the step of cutting the aqueous solution with the oil solution to generate microbeads, the flow rate of the aqueous solution was 20 μL / min, and the flow rate of the oil solution was 3 mL / h.
[0061] The present invention is not limited to the above-mentioned embodiments. If various changes or modifications to the present invention do not depart from the spirit and scope of the present invention, and if these changes and modifications fall within the scope of the claims and equivalent technologies of the present invention, the present invention is also intended to include these changes and modifications.
Claims
1. A method for preparing inverse opal structure photonic crystal microbeads, characterized in that: The following steps are involved: Polystyrene microspheres with a particle size of 200-300 nm are mixed with a first solvent to form a polystyrene emulsion; nano-ferroferric oxide is mixed with a second solvent to form a ferroferric oxide dispersion; Mixing the polystyrene emulsion with the ferroferric oxide dispersion to obtain an aqueous solution; The aqueous solution and the oily solution are respectively injected into different channels in the microfluidic chip, and the aqueous solution and the oily solution are collected at the outlets of their respective channels; wherein the flow rates of the aqueous solution and the oily solution are respectively adjusted in the different channels, so that after the aqueous solution and the oily solution are collected at the outlets of their respective channels, the oily solution cuts the aqueous solution to form microbeads; the oily solution is silicone oil; The microbeads and the oil phase solution enter the microbead generation channel together, and the microbead mixed solution is collected at the outlet of the microbead generation channel; The microbead mixture is dried to remove water and obtain solid microbeads; the solid microbeads are calcined to remove polystyrene and obtain inverse opal structure photonic crystal microbeads.
2. The method for preparing inverse opal structure photonic crystal microbeads according to claim 1, characterized in that: The flow rates of the aqueous solution and the oil-phase solution are adjusted in different pipelines respectively, so that the aqueous solution and the oil-phase solution are combined at their respective pipeline outlets, and in the step of the oil-phase solution cutting the aqueous solution to generate microbeads, the flow rate of the aqueous solution is 2-20 μL / min, the flow rate of the oil-phase solution is 1.5-3 mL / h, and the flow directions of the aqueous solution and the oil-phase solution are perpendicular.
3. The method for preparing inverse opal structure photonic crystal microbeads according to claim 1, characterized in that: In the step of preparing polystyrene microspheres with a particle size of 200-300 nm and a first solvent to form a polystyrene emulsion, the first solvent is deionized water, and the concentration of the polystyrene emulsion is 5-50wt%; In the step of configuring nano-ferroferric oxide and a second solvent to form a ferroferric oxide dispersion, the second solvent is deionized water, and the concentration of the ferroferric oxide dispersion is 2.5-10 wt %.
4. The method for preparing inverse opal structure photonic crystal microbeads according to claim 1, characterized in that: In the step of mixing the polystyrene emulsion with the ferroferric oxide dispersion to obtain an aqueous phase solution, the volume percentage of the polystyrene emulsion to the ferroferric oxide dispersion is 5:1-7:
1.
5. The method for preparing inverse opal structure photonic crystal microbeads according to claim 1, characterized in that: In the step of drying the microbead mixture to remove moisture and obtain solid microbeads, the microbead mixture is evaporated and dried at 60-70° C. to remove moisture, and polystyrene self-assembles to form an opal structure, and nano-iron tetroxide fills the gaps in the opal structure.
6. The method for preparing inverse opal structure photonic crystal microbeads according to claim 1, characterized in that: In the step of calcining the solid microbeads to remove polystyrene and obtain inverse opal structure photonic crystal microbeads, the solid microbeads are calcined at 400-500° C. for 6 hours to remove polystyrene.
7. The method for preparing inverse opal structure photonic crystal microbeads according to claim 1, characterized in that: After the step of obtaining the inverse opal structure photonic crystal microbeads, the inverse opal structure photonic crystal microbeads are soaked in n-hexane.
8. The method for preparing inverse opal structure photonic crystal microbeads according to claim 1, characterized in that: The particle size of nano-ferroferric oxide is 20-50nm.
9. The method for preparing inverse opal structure photonic crystal microbeads according to claim 1, characterized in that: The inner diameter of the microbead generation channel is 200 μm.