All-titanium dioxide one-dimensional photonic crystal and preparation method thereof
阅读说明：本技术 一种全二氧化钛一维光子晶体及其制备方法 (All-titanium dioxide one-dimensional photonic crystal and preparation method thereof ) 是由 胡昕 张翔 陈欣睿 罗铭 于 2019-10-18 设计创作，主要内容包括：本发明公开了一种全二氧化钛一维光子晶体及其制备方法,该一维光子晶体包括1个以上由介孔二氧化钛薄膜和致密二氧化钛薄膜组成的介孔/致密二氧化钛薄膜对,光子禁带中心波长可在260-800纳米之间任意调节,禁带中心波长的反射率最高可达97.3％,介孔/致密二氧化钛薄膜对是通过先旋涂介孔二氧化钛前驱体,光固化,再旋涂致密二氧化钛前驱体,光固化后煅烧得到,其中,介孔二氧化钛前驱体有二氧化钛前驱体、聚苯乙烯和反应性增容剂组成。本发明通过改变聚苯乙烯的含量、浓度及旋涂转速可以容易地获得不同厚度和折射率的二氧化钛薄膜,从而调控其光子禁带中心波长,可廉价、高效地制备大面积全二氧化钛一维光子晶体。(The invention discloses an all-titanium dioxide one-dimensional photonic crystal and a preparation method thereof, the one-dimensional photonic crystal comprises more than 1 mesoporous/compact titanium dioxide film pair consisting of a mesoporous titanium dioxide film and a compact titanium dioxide film, the central wavelength of a photon forbidden band can be randomly adjusted between 260 plus 800 nanometers, the highest reflectivity of the central wavelength of the forbidden band can reach 97.3%, the mesoporous/compact titanium dioxide film pair is obtained by firstly spin-coating a mesoporous titanium dioxide precursor, photocuring, then spin-coating a compact titanium dioxide precursor, and calcining after photocuring, wherein the mesoporous titanium dioxide precursor consists of a titanium dioxide precursor, polystyrene and a reactive compatibilizer. The invention can easily obtain titanium dioxide films with different thicknesses and refractive indexes by changing the content and concentration of polystyrene and the spin coating speed, thereby regulating and controlling the central wavelength of the photon forbidden band and preparing large-area full titanium dioxide one-dimensional photonic crystals with low cost and high efficiency.)
1. The one-dimensional photonic crystal of all titanium dioxide is characterized by comprising more than 1 mesoporous/compact titanium dioxide film pair consisting of a mesoporous titanium dioxide film and a compact titanium dioxide film.
2. The all-titania one-dimensional photonic crystal of claim 1, further comprising a substrate, wherein the mesoporous titania film of the mesoporous/dense titania film pair is attached to the substrate.
3. The all-titania one-dimensional photonic crystal of claim 1, further comprising a substrate, and a dense titania film connected to the substrate, wherein the mesoporous titania film of the mesoporous/dense titania film pair is connected to the dense titania film.
4. The all-titanium dioxide one-dimensional photonic crystal as claimed in any one of claims 1 to 3, wherein in the mesoporous/dense titanium dioxide thin film pair, the thickness of the mesoporous titanium dioxide thin film is 60 to 350 nm, and the thickness of the dense titanium dioxide thin film is 10 to 150 nm.
5. The one-dimensional photonic crystal of all titanium dioxide as claimed in any one of claims 1 to 4, wherein the central wavelength of the photonic band gap of the one-dimensional photonic crystal is arbitrarily adjusted between 260 nm and 800 nm, and the maximum reflectivity of the central wavelength of the band gap is 97.3%.
6. The all-titanium dioxide one-dimensional photonic crystal according to any one of claims 1 to 5, wherein the mesoporous/dense titanium dioxide thin film pair is obtained by spin-coating a mesoporous titanium dioxide precursor solution, curing with visible light, spin-coating a dense titanium dioxide precursor solution, curing with visible light, and calcining.
7. The all-titanium-dioxide one-dimensional photonic crystal according to claim 6, wherein the dense titanium-dioxide precursor solution is obtained by dissolving a titanium-dioxide precursor and a visible light curing system in a first organic solvent.
8. The all-titanium-dioxide one-dimensional photonic crystal according to claim 6, wherein the mesoporous titanium-dioxide precursor solution is obtained by dissolving a titanium-dioxide precursor, polystyrene, a reactive compatibilizer, and a visible light curing system in a second organic solvent.
9. The all-titanium dioxide one-dimensional photonic crystal according to claim 8, wherein the reactive compatibilizer is a reaction product of pentaerythritol mercaptopropionate and styrene, the reaction product having any one of the following chemical structures, or a mixture of any of the following chemical structures:
10. the one-dimensional photonic crystal of all-titanium dioxide according to claim 8 or 9, wherein the reactive compatibilizer is obtained by uniformly mixing pentaerythritol mercaptopropionate, styrene and triethylamine at room temperature and stirring for a while, and then removing unreacted styrene and triethylamine by rotary evaporation under reduced pressure; wherein the mole ratio of the pentaerythritol mercaptopropionate to the styrene is 1: (1-5); and triethylamine accounts for 0.2-2% of the mass sum of pentaerythritol mercaptopropionate and styrene.
Technical Field
The invention belongs to the technical field of film preparation, and particularly relates to an all-titanium dioxide one-dimensional photonic crystal and a preparation method thereof.
Background
One-dimensional photonic crystals are an important thin film device. For one-dimensional photonic crystals, film quality is critical. The optical properties of the film are severely affected by the defects of the film during the preparation process, and the existence of a large number of defects can greatly increase the light scattering and reduce the adhesive force. The Sol-Gel (Sol-Gel) method, the Physical Vapor Deposition (PVD) method and the Chemical Vapor Deposition (CVD) method are the main methods for preparing the titanium dioxide thin film at present, but the Sol-Gel method requires a long Sol preparation process, and the thin film is prone to cracking and poor in adhesion with the substrate during drying and calcining, so that the defects are difficult to overcome, expensive instruments are required by the PVD and CVD methods, and the preparation efficiency needs to be improved. In our previous patent (
The existing method for preparing the mesoporous titanium dioxide film is basically a self-assembly method based on nano particles or a self-assembly method of a template, the preparation efficiency is low, the defects in large-area preparation cannot be controlled, and particularly, the refractive index of the porous film cannot be regulated. Physical deposition methods, such as pulsed laser deposition (document 2l.c. luca Passoni et al, Self-Assembled nanoscale structures for High-Efficiency Porous photonic crystals, ACS Nano 2014,8, 12167-.
Disclosure of Invention
In view of the above problems, the present invention provides an all-titanium dioxide one-dimensional photonic crystal and a method for preparing the same.
The technical scheme adopted for achieving the purpose of the invention is as follows: the one-dimensional photonic crystal of all titanium dioxide comprises more than 1 mesoporous/compact titanium dioxide film pair consisting of a mesoporous titanium dioxide film and a compact titanium dioxide film.
Preferably, the one-dimensional photonic crystal further comprises a substrate, and the mesoporous titanium dioxide film in the mesoporous/dense titanium dioxide film pair is connected with the substrate.
Preferably, the one-dimensional photonic crystal further comprises a substrate and a compact titanium dioxide film connected with the substrate, and the mesoporous titanium dioxide film in the mesoporous/compact titanium dioxide film pair is connected with the compact titanium dioxide film.
Preferably, the mesoporous/compact titanium dioxide film is centered, the thickness of the mesoporous titanium dioxide film is 60-350 nanometers, and the thickness of the compact titanium dioxide film is 10-150 nanometers.
Preferably, the central wavelength of the photonic forbidden band of the one-dimensional photonic crystal is randomly adjusted between 260-800 nanometers, and the maximum reflectivity of the central wavelength of the forbidden band is 97.3%.
Preferably, the mesoporous/dense titanium dioxide film pair is obtained by spin-coating a mesoporous titanium dioxide precursor solution, performing visible light curing, then spin-coating a dense titanium dioxide precursor solution, performing visible light curing, and then calcining.
Preferably, the thickness of each mesoporous/dense titanium dioxide film pair may be the same or different, and is designed according to the requirement.
Specifically, the compact titanium dioxide precursor solution is obtained by dissolving a titanium dioxide precursor and a visible light curing system in an organic solvent.
More specifically, the titanium dioxide precursor is a reaction product of alkoxy titanium and acetoacetic acid ethylene glycol methacrylate, and the reaction product has any one of the following chemical structures or a mixture of any several of the following chemical structures:
wherein R is ethyl, butyl or isopropyl, and n is 1-5.
More specifically, the titanium dioxide precursor is obtained by uniformly mixing alkoxy titanium and acetoacetic acid glycol methacrylate, cooling to room temperature, adding an ethanol solution under the stirring condition for reaction, and carrying out reduced pressure rotary evaporation to remove reaction byproducts, wherein the molar ratio of the alkoxy titanium to the acetoacetic acid glycol methacrylate is 1: (0.5 to 2); the water content in the ethanol solution is 0-5 mol% of alkoxy titanium, the ethanol content in the ethanol solution is 1-5% of the sum of the mass of the alkoxy titanium and the mass of the acetoacetic acid ethylene glycol methacrylate, and the alkoxy titanium is selected from one or more of tetraethyl titanate, tetrabutyl titanate and tetraisopropyl titanate.
More specifically, the visible light curing system comprises a photoinitiator and a co-initiator, wherein the photoinitiator is camphorquinone, and the co-initiator is ethyl 4-dimethylaminobenzoate.
More specifically, the organic solvent is one or more selected from ethylene glycol monomethyl ether, tert-butyl methacrylate and methyl methacrylate.
Specifically, the mesoporous titanium dioxide precursor solution is obtained by dissolving a titanium dioxide precursor, polystyrene, a reactive compatibilizer and a visible light curing system in an organic solvent.
More specifically, the organic solvent is one or more selected from toluene, xylene and chlorobenzene.
More specifically, the reactive compatibilizer is a reactant of pentaerythritol mercaptopropionate and styrene, and the reaction product has any one of the following chemical structures or a mixture of any several of the following chemical structures:
more specifically, the reactive compatibilizer is obtained by uniformly mixing pentaerythritol mercaptopropionate, styrene and triethylamine at room temperature, stirring for a period of time, and then carrying out reduced pressure rotary evaporation to remove unreacted styrene and triethylamine; wherein the mole ratio of the pentaerythritol mercaptopropionate to the styrene is 1: (1-5); and triethylamine accounts for 0.2-2% of the mass sum of pentaerythritol mercaptopropionate and styrene.
The preparation method of the all-titanium dioxide one-dimensional photonic crystal comprises the following steps:
1) preparing a compact titanium dioxide film on the surface of the substrate;
2) spin-coating a layer of mesoporous titanium dioxide precursor solution on the surface of the compact titanium dioxide film obtained in the step 1), and curing by visible light in an inert gas atmosphere;
3) repeating the step 2) for more than 0 times;
4) then spin-coating a layer of compact titanium dioxide precursor solution on the surface of the titanium dioxide precursor solution, and curing the titanium dioxide precursor solution by visible light under the inert gas atmosphere;
5) repeating the step 4) for more than 0 times;
6) calcining the titanium dioxide film in a muffle furnace to obtain 1 mesoporous/compact titanium dioxide film pair;
7) repeating the steps 2) to 6) for more than 0 times to obtain the all-titanium dioxide one-dimensional photonic crystals with different cycles, namely different numbers of mesoporous/compact titanium dioxide film pairs.
The preparation method of the all-titanium dioxide one-dimensional photonic crystal can also be prepared by the following steps:
1) spin-coating a layer of mesoporous titanium dioxide precursor solution on the surface of the substrate, and curing by using visible light under the inert gas atmosphere;
2) repeating the step 1) for more than 0 times;
3) then a layer of compact titanium dioxide precursor solution is coated on the surface of the titanium dioxide precursor solution in a spinning mode, and visible light is used for curing in the inert gas atmosphere;
4) repeating the step 3) for more than 0 times;
5) calcining the titanium dioxide film in a muffle furnace to obtain 1 mesoporous/compact titanium dioxide film pair;
6) repeating the steps 1) to 5) for more than 0 times to obtain the all-titanium dioxide one-dimensional photonic crystals with different periods, namely different numbers of mesoporous/compact titanium dioxide film pairs.
Preferably, when the visible light source is used for curing, the curing time is 10 minutes; the calcination temperature is 400-700 ℃, and the calcination time is 2-20 minutes.
Compared with the prior art, the invention has the advantages that:
1) when the mesoporous titanium dioxide film is prepared, the reactive compatibilizer is added, so that the phase separation size of the high-molecular pore-forming agent is reduced, and the problem that defects are easy to generate during calcination is solved; polystyrene is selected as a proper pore-making agent, and because the thermal decomposition temperature of the polystyrene is between the two thermal decomposition temperatures of the titanium dioxide precursor, and the polystyrene has a certain carbon residue rate, when the mixture is thermally decomposed, the residual carbon of the polystyrene can be used as a separant to prevent titanium dioxide nanoparticles from agglomerating and enlarging or being converted into a compact film.
2) The invention overcomes the problem that the refractive index is limited by the size of colloidal particles when preparing the mesoporous titanium dioxide film by a sol-gel method, and the refractive index can be adjusted by the dosage of polystyrene.
3) The invention can prepare the all-titanium dioxide one-dimensional photonic crystal and the mesoporous titanium dioxide film with different refractive indexes with low cost and high efficiency.
Drawings
FIG. 1 shows the effect of the amount of the reactive compatibilizer used in example 6 on the surface morphology of the mesoporous titanium dioxide film.
FIG. 2 shows the effect of the kind of the reactive compatibilizer in example 7 on the morphology of the mesoporous titanium dioxide film.
FIG. 3 is an SEM cross-sectional photograph of an all-titania one-dimensional photonic crystal of example 9.
FIG. 4 shows the reflectance spectra of example 9, comparative example 1, and simulations.
FIG. 5 is a schematic diagram of a full titanium dioxide/titanium dioxide one-dimensional photonic crystal structure according to the present invention.
FIG. 6 is a schematic view of another all-titania/titania one-dimensional photonic crystal structure according to the present invention.
Detailed Description
The following detailed description of the present invention will be further described with reference to the accompanying drawings and examples to facilitate further understanding of the present invention by those skilled in the art, and should not be construed as limiting the claims.
Based on the problems in the prior art, the invention designs an all-titanium dioxide one-dimensional photonic crystal and a novel preparation method thereof, and the method adopts the reaction of pentaerythritol mercaptopropionate and styrene to prepare a reactive compatibilizer; taking a chelate prepared by reacting alkoxy titanium and acetoacetic acid ethylene glycol methacrylate as a titanium dioxide precursor, dissolving the titanium dioxide precursor in an organic solvent, adding a visible light initiation system to prepare a compact titanium dioxide precursor solution, and independently spin-coating the solution on a substrate and calcining the solution to obtain a titanium dioxide compact film; dissolving a titanium dioxide precursor, polystyrene, a reactive compatibilizer and a visible light initiation system in an organic solvent to prepare a mesoporous titanium dioxide precursor solution, directly spin-coating the mesoporous titanium dioxide precursor solution on a substrate or spin-coating the mesoporous titanium dioxide precursor solution on the substrate which is independently spin-coated with a titanium dioxide dense film, spin-coating the dense titanium dioxide precursor solution on the surface of the substrate after visible light curing, calcining the mesoporous titanium dioxide precursor solution after visible light curing to obtain a mesoporous/dense titanium dioxide film pair, repeatedly preparing the mesoporous/dense titanium dioxide film pair, adjusting photon forbidden bands of the mesoporous/dense titanium dioxide film pair by controlling the film thickness to obtain full titanium dioxide one-dimensional photonic crystals with different structural colors, wherein the central wavelength of the forbidden bands can be adjusted within 260-800 nanometers, and the reflectivity can reach as.
With reference to fig. 5, the all-titania/titania one-dimensional photonic crystal of the present invention is composed of a substrate and n mesoporous/dense titania film pairs, wherein the mesoporous/dense titania film pairs are composed of a mesoporous titania film and a dense titania film, and the mesoporous titania film in the mesoporous/dense titania film pairs is connected to the substrate.
With reference to fig. 6, the all-titania/titania one-dimensional photonic crystal according to the present invention is composed of a substrate, a dense titania film connected to the substrate, and n mesoporous/dense titania film pairs, wherein the mesoporous/dense titania film pairs are composed of a mesoporous titania film and a dense titania film, and the mesoporous titania film in the mesoporous/dense titania film pairs is connected to the dense titania film connected to the substrate.
The preparation method of the all-titanium dioxide/titanium dioxide one-dimensional photonic crystal comprises two methods, wherein the first method comprises the following steps:
1) titanium dioxide precursor preparation
Uniformly mixing metered alkoxy titanium and acetoacetic acid ethylene glycol methacrylate, cooling to room temperature, dissolving metered deionized water in ethanol to prepare an ethanol solution, and adding the ethanol solution to react under the stirring condition; and (3) carrying out reduced pressure rotary evaporation to remove reaction byproducts, thus obtaining a titanium dioxide precursor, wherein the molar ratio of alkoxy titanium to acetoacetic acid ethylene glycol methacrylate is 1: (0.5 to 2); the dosage of the deionized water is 0-5 mol% relative to the alkoxy titanium, the dosage of the ethanol is 1-5% of the sum of the mass of the alkoxy titanium and the mass of the acetoacetic acid ethylene glycol methacrylate, and the alkoxy titanium is selected from one or more of tetraethyl titanate, tetrabutyl titanate and tetraisopropyl titanate;
2) preparation of reactive compatibilizers
Uniformly mixing pentaerythritol mercaptopropionate, styrene and triethylamine at room temperature, stirring for a period of time, and carrying out reduced pressure rotary evaporation to remove unreacted styrene and triethylamine to obtain the product; wherein the mole ratio of the pentaerythritol mercaptopropionate to the styrene is 1: (1-5); triethylamine accounts for 0.2-2% of the mass sum of pentaerythritol mercaptopropionate and styrene;
3) preparation of dense titanium dioxide precursor solution
Dissolving the titanium dioxide precursor prepared in the step 1) in an organic solvent, adding a visible light curing system to obtain a compact titanium dioxide precursor solution, and sealing in a dark place for later use, wherein the visible light curing system comprises a photoinitiator and an auxiliary initiator, the photoinitiator is camphorquinone, the auxiliary initiator is ethyl 4-dimethylaminobenzoate, and the organic solvent is one or more selected from methyl methacrylate, tert-butyl methacrylate or ethylene glycol monomethyl ether;
4) preparation of mesoporous titanium dioxide precursor solution
Dissolving the titanium dioxide precursor prepared in the step 1), styrene and the reactive compatibilizer prepared in the step 2) in an organic solvent, adding a visible light curing system to obtain a mesoporous titanium dioxide precursor solution, and sealing the solution in a dark place for later use, wherein the visible light curing system comprises a photoinitiator and an auxiliary initiator, the photoinitiator is camphorquinone, the auxiliary initiator is ethyl 4-dimethylaminobenzoate, and the organic solvent is one or more selected from toluene, xylene and chlorobenzene;
5) preparation of dense titanium dioxide film
Spin-coating a layer of compact titanium dioxide precursor on the surface of the substrate and curing for 10 minutes by visible light under the inert gas atmosphere; then calcining the titanium dioxide film in a muffle furnace at the temperature of 400-700 ℃ for 2-20 minutes to obtain a compact titanium dioxide film;
6) preparation of mesoporous/dense titanium dioxide film pair
Spin-coating a layer of mesoporous titanium dioxide precursor solution on the surface of the compact titanium dioxide film obtained in the step 5), curing for 10 minutes by visible light in an inert gas atmosphere, repeating the step for more than 0 times, spin-coating a layer of compact titanium dioxide precursor on the surface of the compact titanium dioxide film, curing for 10 minutes by visible light in an inert gas atmosphere, and repeating the step for more than 0 times; then placing the titanium dioxide film in a muffle furnace to calcine for 2-20 minutes at 400-700 ℃ to obtain 1 mesoporous/compact titanium dioxide film pair;
7) preparation of full titanium dioxide one-dimensional photonic crystal
Repeating the step 6) for more than 0 times to obtain the all-titanium dioxide one-dimensional photonic crystals with different periods.
Or, the preparation method of the all-titanium dioxide/titanium dioxide one-dimensional photonic crystal comprises two methods, wherein the second method comprises the following steps:
1) titanium dioxide precursor preparation
Uniformly mixing metered alkoxy titanium and acetoacetic acid ethylene glycol methacrylate, cooling to room temperature, dissolving metered deionized water in ethanol to prepare an ethanol solution, and adding the ethanol solution to react under the stirring condition; and (3) carrying out reduced pressure rotary evaporation to remove reaction byproducts, thus obtaining a titanium dioxide precursor, wherein the molar ratio of alkoxy titanium to acetoacetic acid ethylene glycol methacrylate is 1: (0.5 to 2); the dosage of the deionized water is 0-5 mol% relative to the alkoxy titanium, the dosage of the ethanol is 1-5% of the sum of the mass of the alkoxy titanium and the mass of the acetoacetic acid ethylene glycol methacrylate, and the alkoxy titanium is selected from one or more of tetraethyl titanate, tetrabutyl titanate and tetraisopropyl titanate;
2) preparation of reactive compatibilizers
Uniformly mixing pentaerythritol mercaptopropionate, styrene and triethylamine at room temperature, stirring for a period of time, and carrying out reduced pressure rotary evaporation to remove unreacted styrene and triethylamine to obtain the product; wherein the mole ratio of the pentaerythritol mercaptopropionate to the styrene is 1: (1-5); triethylamine accounts for 0.2-2% of the mass sum of pentaerythritol mercaptopropionate and styrene;
3) preparation of dense titanium dioxide precursor solution
Dissolving the titanium dioxide precursor prepared in the step 1) in an organic solvent, adding a visible light curing system to obtain a compact titanium dioxide precursor solution, and sealing in a dark place for later use, wherein the visible light curing system comprises a photoinitiator and an auxiliary initiator, the photoinitiator is camphorquinone, the auxiliary initiator is ethyl 4-dimethylaminobenzoate, and the organic solvent is one or more selected from methyl methacrylate, tert-butyl methacrylate or ethylene glycol monomethyl ether;
4) preparation of mesoporous titanium dioxide precursor solution
Dissolving the titanium dioxide precursor prepared in the step 1), styrene and the reactive compatibilizer prepared in the step 2) in an organic solvent, adding a visible light curing system to obtain a mesoporous titanium dioxide precursor solution, and sealing the solution in a dark place for later use, wherein the visible light curing system comprises a photoinitiator and an auxiliary initiator, the photoinitiator is camphorquinone, the auxiliary initiator is ethyl 4-dimethylaminobenzoate, and the organic solvent is one or more selected from toluene, xylene and chlorobenzene;
5) preparation of mesoporous/dense titanium dioxide film pair
Firstly, spin-coating a layer of mesoporous titanium dioxide precursor solution on the surface of the substrate, curing for 10 minutes by visible light under the atmosphere of inert gas, repeating the step for more than 0 time, then spin-coating a layer of compact titanium dioxide precursor on the surface of the substrate, curing for 10 minutes by visible light under the atmosphere of inert gas, and repeating the step for more than 0 time; calcining the titanium dioxide film in a muffle furnace at the temperature of 400-700 ℃ for 2-20 minutes to obtain 1 mesoporous/compact titanium dioxide film pair;
6) preparation of full titanium dioxide one-dimensional photonic crystal
Repeating the step 5) for more than 0 times to obtain the all-titanium dioxide one-dimensional photonic crystals with different periods.
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