Organic inverse opal photonic crystal with fluorescence and preparation method thereof
By introducing fluorescent molecules through organic polymerization in inverse opal photonic crystals, the problem of poor binding fastness of fluorescence signals is solved, and the signal intensity is improved, which is suitable for areas such as response discoloration and sensing detection.
Patent Information
- Application Number
- CN202311119621.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-08-31
- Publication Date
- 2025-02-28
AI Technical Summary
In the prior art, the binding fastness of the fluorescent signal in the anti-opal photonic crystal is poor, resulting in insufficient signal strength and it is difficult to meet the application needs in the field of responsive discoloration.
Through organic polymerization, fluorescent molecules are introduced into the polymer molecular chain as fluorescent monomers, and through the binding of chemical bonds, fluorescent molecules are firmly introduced into the anti-opal photonic crystal structure.
The binding stability and signal intensity of fluorescent signals are improved, making the photonic crystal more stable and powerful in structural color and fluorescent signals, and is suitable for sensing detection and other fields.
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Figure CN119529366A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of preparation of chromogenic materials, and in particular relates to an organic inverse opal photonic crystal with fluorescence and a preparation method thereof. Background Art
[0002] Inverse opal photonic crystals are photonic crystals prepared using opal photonic crystals as templates, and have a continuous and ordered porous structure. The photonic bandgap, as a notable feature of photonic crystals, has a significant modulation effect on light. When the photonic bandgap of the inverse opal photonic crystal is in the visible light region, light of a specific frequency is reflected because it cannot pass through, and coherent diffraction occurs under the action of the periodic structure to produce structural colors visible to the naked eye. Organic inverse opal photonic crystals can respond to external stimuli by reversibly modulating the lattice parameters and the effective refractive index to produce changes in structural colors, and have obvious advantages in the field of responsive color change.
[0003] Photons at the edge of the bandgap have a slow light effect, which can significantly enhance the interaction between light and matter. Regulating the maximum excitation wavelength or maximum emission wavelength of fluorescence to be located at the edge of the photon bandgap can significantly enhance the fluorescence signal. At present, there are many studies on the introduction of fluorescence signals into inverse opal photonic crystals, but most of the studies use inverse opal photonic crystals as a skeleton support and introduce fluorescent molecules, quantum dots, etc. on the surface of its porous structure by adsorption or loading to construct fluorescent inverse opal photonic crystals. Since this introduction method relies heavily on intermolecular electrostatic effects, hydrogen bonds, etc. for binding, this introduction method has the problem of poor binding strength and needs to be improved. Summary of the invention
[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide an organic inverse opal photonic crystal with fluorescence having high fluorescence binding stability and high signal intensity and a preparation method thereof.
[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions.
[0006] A method for preparing an organic inverse opal photonic crystal with fluorescence comprises the following steps:
[0007] (1) adding a polymerizable monomer, a crosslinking agent, and an initiator to a solvent at a molar ratio of 10:1 to 3:1, and adding a fluorescent molecule to obtain a precursor; wherein the polymerizable monomer comprises one or more of methacrylic acid, hydroxyethyl methacrylate, acrylic acid, acrylamide, and N-isopropylacrylamide, and the fluorescent molecule comprises one or more of protoporphyrin, zinc protoporphyrin, dimethyl protoporphyrin, dihydrochlorin e6, coumarins, AIE molecules, and ionic liquids;
[0008] (2) covering the surface of the opal photonic crystal template assembled on the substrate with an organic film, so that the organic film, the opal photonic crystal and the substrate form a "sandwich" structure, and then filling the precursor obtained in step (1) into the pores of the "sandwich" structure, and then performing ultraviolet polymerization or thermal polymerization;
[0009] (3) removing the organic film and template of the sample obtained after polymerization in step (2) to obtain an organic inverse opal photonic crystal with fluorescence.
[0010] In the above-mentioned method for preparing the fluorescent organic inverse opal photonic crystal, preferably, in step (1), the cross-linking agent comprises methylene bisacrylamide and / or ethylene glycol dimethacrylate.
[0011] In the above-mentioned method for preparing fluorescent organic inverse opal photonic crystals, preferably, in step (1), the initiator includes one of 2-hydroxy-methylphenylpropane-1-one (1173), 1-hydroxycyclohexylphenyl ketone (184), diethoxyacetophenone and azobisisobutyronitrile (AIBN).
[0012] In the above-mentioned method for preparing the fluorescent organic inverse opal photonic crystal, preferably, in step (1), the solvent comprises one or more of water, ethanol, methanol and chloroform.
[0013] In the above-mentioned method for preparing the fluorescent organic inverse opal photonic crystal, preferably, in step (2), the organic film comprises a polymethyl methacrylate (PMMA) film or a polyethylene terephthalate (PET) film.
[0014] In the above-mentioned method for preparing fluorescent organic inverse opal photonic crystals, preferably, in step (2), the opal photonic crystals include polystyrene opal photonic crystals, polymethyl methacrylate opal photonic crystals or silica opal photonic crystals.
[0015] In the above-mentioned method for preparing fluorescent organic inverse opal photonic crystals, preferably, in step (2), the average particle size of the opal photonic crystals is 180 nm to 300 nm.
[0016] In the above-mentioned method for preparing the fluorescent organic inverse opal photonic crystal, preferably, in step (2), the time of the ultraviolet polymerization is 2 min to 10 min; and the temperature of the thermal polymerization is 60° C. to 80° C.
[0017] As a general technical concept, the present invention also provides an organic inverse opal photonic crystal with fluorescence obtained by the above-mentioned preparation method.
[0018] Compared with the prior art, the advantages of the present invention are:
[0019] 1. The present invention chemically grafts fluorescent molecules with active groups such as double bonds by organic polymerization, directly grafting them into the polymer chain of the inverse opal photonic crystal to construct an organic inverse opal photonic crystal with fluorescence. Compared with the introduction of fluorescence by surface adsorption / loading and other methods, the stability of the material of the present invention is guaranteed. At the same time, the present invention gives the photonic crystal a fluorescent signal while constructing the structural color, and utilizes the slow light effect of the photon bandgap to enhance the intensity of the fluorescent signal, thereby improving the signal intensity. The present invention utilizes the combination of chemical bonds to firmly introduce the fluorescent molecules into the inverse opal photonic crystal skeleton structure, effectively improving the binding stability of the fluorescent molecules while obtaining the photonic crystal structural color.
[0020] 2. The method of the present invention is easy to operate, has stable fluorescence binding, and has broad application prospects in the fields of sensing and detection. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a scanning electron microscope image of the surface morphology of the polystyrene opal photonic crystal used in Example 1 of the present invention.
[0022] Figure 2 This is a surface scanning electron microscope image of the fluorescent organic inverse opal photonic crystal prepared in Example 1 of the present invention.
[0023] Figure 3 This is a cross-sectional scanning electron microscope image of the fluorescent organic inverse opal photonic crystal prepared in Example 1 of the present invention.
[0024] Figure 4 This is a reflection spectrum diagram of the fluorescent organic inverse opal photonic crystal prepared in Example 1 of the present invention.
[0025] Figure 5 This is a fluorescence spectrum diagram of the fluorescent organic inverse opal photonic crystal prepared in Example 1 of the present invention. DETAILED DESCRIPTION
[0026] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby. The materials and instruments used in the following embodiments are all commercially available.
[0027] Example 1
[0028] A method for preparing a fluorescent organic inverse opal photonic crystal of the present invention comprises the following steps:
[0029] (1) mixing hydroxyethyl methacrylate, ethylene glycol dimethacrylate and 2-hydroxy-methylphenylpropane-1-one (photoinitiator 1173) in a mixed solution of ethanol and water at a molar ratio of 10:1:1, wherein the volume ratio of ethanol to water in the mixed solution is 3:1, and adding an appropriate amount (specifically 10 mg) of ionic liquid to obtain a precursor;
[0030] In this embodiment, the preparation process of the ionic liquid is as follows: 2 mmol of 4-bromomethyl-7-methoxycoumarin is dissolved in chloroform, and then 4 mmol of 1-vinyl imidazole is added, and the mixture is reacted in an oil bath at 80° C. for 12 h, and then washed with anhydrous ether to obtain an ionic liquid, which is dried for later use.
[0031] (2) Covering the surface of a polystyrene opal photonic crystal template assembled on a substrate (specifically, a glass substrate) with a PET film, wherein the average particle size of the polystyrene opal photonic crystal is 232 nm, and the organic film, the opal photonic crystal and the substrate form a "sandwich" structure, and the precursor obtained in step (1) is spontaneously infiltrated into the pores of the "sandwich" structure by capillary action to fill the pores, and after the bubbles are discharged, the pores are placed under an ultraviolet lamp for irradiation to perform a photopolymerization reaction for 2-3 minutes;
[0032] In this embodiment, the polystyrene opal photonic crystal can firstly prepare polystyrene microspheres by emulsion polymerization, and then construct the monodisperse polystyrene microspheres into polystyrene opal photonic crystals on a substrate by heating convection self-assembly. Both emulsion polymerization and heating convection self-assembly are conventional methods.
[0033] (3) The photopolymerized sample is first placed in an ethanol solution, the PET film is manually peeled off, and then the sample is immersed in a DMF solution to remove the template, thereby obtaining an organic inverse opal photonic crystal with fluorescence.
[0034] Figure 1 This is a SEM image of the polystyrene opal photonic crystal template used in Example 1. The microspheres are regularly arranged in the form of an FCC array. Figure 2 This is a surface scanning electron micrograph of the fluorescent organic inverse opal photonic crystal obtained in Example 1. The sample exhibits a porous structure and the FCC array of the template is well maintained. Figure 3 This is a scanning electron microscope image of the cross section of the fluorescent organic inverse opal photonic crystal obtained in Example 1, which exhibits a regular and ordered porous structure identical to the surface. Figure 4 This is a reflection spectrum diagram of the fluorescent organic inverse opal photonic crystal obtained in Example 1 in water. The maximum reflection wavelength in water is 535 nm, showing a green structural color. Figure 5The fluorescence spectrum of the fluorescent organic inverse opal photonic crystal obtained in Example 1 under the excitation wavelength of 330nm is obtained. Its emission wavelength is 392nm, emitting blue fluorescence. The sample is not affected after multiple solvent washings, multiple swelling and shrinking, and its fluorescence signal still exists. Fluorescence can still be seen after multiple ultraviolet irradiation.
[0035] Example 2
[0036] A method for preparing a fluorescent organic inverse opal photonic crystal of the present invention is basically the same as that of Example 1, except that in the ionic liquid preparation process of step (1), 4-bromomethyl-7-methoxycoumarin is replaced by 1-(4-bromophenyl)-1,2,2-triphenylethylene.
[0037] Example 3
[0038] A method for preparing a fluorescent organic inverse opal photonic crystal of the present invention is basically the same as that of Example 1, except that: in step (1), the ionic liquid is replaced with a protoporphyrin zinc solution (0.2 mg / mL, 200 μL is added); in step (2), the average particle size of the polystyrene opal photonic crystal template is 241 nm.
[0039] Example 4
[0040] A method for preparing a fluorescent organic inverse opal photonic crystal of the present invention is substantially the same as that of Example 3, except that in step (1), the protoporphyrin zinc solution is replaced by a protoporphyrin solution.
[0041] Example 5
[0042] A method for preparing a fluorescent organic inverse opal photonic crystal of the present invention is substantially the same as that of Example 3, except that in step (1), the protoporphyrin zinc solution is replaced by a protoporphyrin dimethyl ester solution.
[0043] Example 6
[0044] A method for preparing a fluorescent organic inverse opal photonic crystal of the present invention is substantially the same as that of Example 1, except that in step (1), hydroxyethyl methacrylate is replaced by acrylamide.
[0045] Example 7
[0046] A method for preparing a fluorescent organic inverse opal photonic crystal of the present invention is basically the same as that of Example 1, except that in step (1), hydroxyethyl methacrylate is replaced by N-isopropylacrylamide.
[0047] Example 8
[0048] A method for preparing a fluorescent organic inverse opal photonic crystal of the present invention is basically the same as that of Example 1, except that: in step (1), the polystyrene opal photonic crystal is replaced by a silica opal photonic crystal; and in step (4), the DMF solution is replaced by an HF solution.
[0049] The present invention introduces fluorescent molecules as fluorescent monomers into polymer molecular chains by means of organic polymerization, and firmly introduces the fluorescent molecules into the photonic crystal structure by chemical bond combination, thereby effectively improving the binding stability of the introduced fluorescence while obtaining the photonic crystal structural color. The method is easy to operate and has stable fluorescence binding, and has broad application prospects in the fields of sensing and detection.
[0050] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as above in the preferred embodiment, it is not used to limit the present invention. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention, still fall within the scope of protection of the technical solution of the present invention.
Claims
1. A method for preparing a fluorescent organic inverse opal photonic crystal, characterized in that: The following steps are involved: (1) adding a polymerizable monomer, a crosslinking agent, and an initiator to a solvent at a molar ratio of 10:1 to 3:1, and adding a fluorescent molecule to obtain a precursor; wherein the polymerizable monomer comprises one or more of methacrylic acid, hydroxyethyl methacrylate, acrylic acid, acrylamide, and N-isopropylacrylamide, and the fluorescent molecule comprises one or more of protoporphyrin, zinc protoporphyrin, dimethyl protoporphyrin, dihydrochlorin e6, coumarins, AIE molecules, and ionic liquids; (2) covering the surface of the opal photonic crystal template assembled on the substrate with an organic film, so that the organic film, the opal photonic crystal and the substrate form a "sandwich" structure, and then filling the precursor obtained in step (1) into the pores of the "sandwich" structure, and then performing ultraviolet polymerization or thermal polymerization; (3) removing the organic film and template of the sample obtained after polymerization in step (2) to obtain an organic inverse opal photonic crystal with fluorescence.
2. The method for preparing the fluorescent organic inverse opal photonic crystal according to claim 1, characterized in that: In step (1), the cross-linking agent includes methylene bisacrylamide and / or ethylene glycol dimethacrylate.
3. The method for preparing the fluorescent organic inverse opal photonic crystal according to claim 1, characterized in that: In step (1), the initiator includes one of 2-hydroxy-methylphenylpropane-1-one, 1-hydroxycyclohexyl phenyl ketone, diethoxyacetophenone and azobisisobutyronitrile.
4. The method for preparing the fluorescent organic inverse opal photonic crystal according to claim 1, characterized in that: In step (1), the solvent includes one or more of water, ethanol, methanol and chloroform.
5. The method for preparing a fluorescent organic inverse opal photonic crystal according to any one of claims 1 to 4, characterized in that: In step (2), the organic film includes a polymethyl methacrylate film or a polyethylene terephthalate film.
6. The method for preparing a fluorescent organic inverse opal photonic crystal according to any one of claims 1 to 4, characterized in that: In step (2), the opal photonic crystal includes polystyrene opal photonic crystal, polymethyl methacrylate opal photonic crystal or silica opal photonic crystal.
7. The method for preparing a fluorescent organic inverse opal photonic crystal according to any one of claims 1 to 4, characterized in that: In step (2), the average particle size of the opal photonic crystals is 180 nm to 300 nm.
8. The method for preparing a fluorescent organic inverse opal photonic crystal according to any one of claims 1 to 4, characterized in that: In step (2), the time of the ultraviolet polymerization is 2 min to 10 min; the temperature of the thermal polymerization is 60° C. to 80° C.
9. An organic inverse opal photonic crystal with fluorescence obtained by the preparation method according to any one of claims 1 to 8.