Quantum dot modification-based high-efficiency multicolor luminous silica powder composite material as well as preparation method and application of quantum dot modification-based high-efficiency multicolor luminous silica powder composite material

Abstract

The invention belongs to the technical field of photoelectric materials, and provides a quantum dot modification-based high-efficiency multicolor light-emitting silica powder composite material as well as a preparation method and application of the quantum dot modification-based high-efficiency multicolor light-emitting silica powder composite material. The preparation method comprises the following steps: mixing a cadmium source solution and a selenium source solution for reaction to obtain CdSe quantum dots; the CdSe quantum dots and a zinc source solution are mixed for a reaction, and CdSe / ZnS quantum dots are obtained; the preparation method comprises the following steps: mixing CdSe / ZnS quantum dots, an organic solvent and a silanization reagent for reaction to obtain modified quantum dots; mixing the modified quantum dots and silica powder for reaction to obtain modified silica powder; and mixing the modified silica powder with a binder to obtain the product. The product is suitable for traffic signal lamps and fire-fighting indicating lamps, the photoelectric performance and the environmental stability of the signal lamps are remarkably improved, the visibility and the safety of the signal lamps are improved through multi-color display and reflection performance enhancement, and the product has remarkable application prospects and economic benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of optoelectronic materials, and particularly to a high-efficiency multicolor luminescent silicon micropowder composite material modified by quantum dots, a preparation method thereof, and an application thereof. Background Art

[0002] In modern urban management, traffic signal lights and fire indicator lights are important devices to ensure traffic safety and emergency response. Traditional traffic signal lights and fire indicator lights mainly rely on LEDs and fluorescent materials to provide light sources. Although these materials have relatively high luminous efficiency, the following problems exist in the application process: (1) Balance between luminous efficiency and energy consumption: When traditional LEDs and fluorescent materials improve luminous efficiency, they are often accompanied by high energy consumption, which is particularly prominent for signal lights used for a long time and at high frequencies; (2) Environmental stability: LEDs are prone to aging under harsh environments such as high temperature and high humidity, and the light decay rate of fluorescent materials is relatively fast, which leads to a reduction in the reliability of signal lights during long-term use; (3) Insufficient reflectivity: Existing traffic signal lights and fire indicator lights have insufficient reflectivity when the light source is turned off or the light is insufficient, which affects their visibility and recognition at night or in emergency situations; (4) Limitations of multicolor display: Traditional signal lights are difficult to achieve multicolor display through simple adjustment, which limits their flexibility and recognizability in different application scenarios.

[0003] Therefore, it is of great significance to provide a traffic signal light and a fire indicator light with high brightness, low energy consumption, long lifespan, excellent reflectivity, and capable of achieving multicolor display. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problems existing in the prior art, and provide a high-efficiency multicolor luminescent silicon micropowder composite material modified by quantum dots, a preparation method thereof, and an application thereof, which are used to improve the brightness, environmental stability, and reflectivity of traffic signal lights and fire indicator lights, and simultaneously achieve multicolor luminescence display.

[0005] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0006] The present invention provides a preparation method of a high-efficiency multicolor luminescent silicon micropowder composite material modified by quantum dots, comprising the following steps:

[0007] (1) Mix a cadmium source solution and a selenium source solution and react to obtain CdSe quantum dots;

[0008] (2) Mix the CdSe quantum dots and a zinc source solution and react to obtain CdSe / ZnS quantum dots;

[0009] (3) Mix the CdSe / ZnS quantum dots, organic solvent and silanizing reagent, and carry out a reaction to obtain modified quantum dots;

[0010] (4) Mix the modified quantum dots and silica powder, and carry out a reaction to obtain modified silica powder;

[0011] (5) Mix the modified silica powder and binder to obtain the efficient multicolor luminescent silica powder composite material modified based on quantum dots.

[0012] Preferably, the cadmium source in the cadmium source solution in step (1) includes cadmium oxide, cadmium acetate or cadmium chloride; the solvent of the cadmium source solution includes oleylamine or oleic acid; the concentration of the cadmium source solution is 0.1 - 0.2 mol / L;

[0013] The selenium source in the selenium source solution in step (1) includes selenium powder or hydrogen selenide; the solvent of the selenium source solution includes trioctylphosphine or oleylamine; the concentration of the selenium source solution is 0.1 - 0.15 mol / L;

[0014] The molar ratio of the cadmium source in the cadmium source solution to the selenium source in the selenium source solution in step (1) is 1 - 2:1.

[0015] Preferably, the temperature of the reaction in step (1) is 180 - 220 °C, and the reaction time is 20 - 40 min.

[0016] Preferably, the zinc source in the zinc source solution in step (2) includes zinc acetate or zinc chloride; the solvent of the zinc source solution includes oleylamine or oleic acid; the concentration of the zinc source solution is 0.1 - 0.15 mol / L;

[0017] The molar ratio of the CdSe quantum dots to the zinc source in the zinc source solution in step (2) is 1.5 - 2:1;

[0018] The temperature of the reaction in step (2) is 180 - 220 °C, and the reaction time is 20 - 40 min.

[0019] Preferably, the organic solvent in step (3) includes n - hexane, toluene or chloroform; the silanizing reagent includes 3 - mercaptopropyltrimethoxysilane 、 aminopropyltriethoxysilane, phenyltriethoxysilane or trimethoxysilane;

[0020] The mass - volume ratio of the CdSe / ZnS quantum dots, organic solvent and silanizing reagent in step (3) is 1 kg:20 - 40 L:0.2 - 0.5 L.

[0021] Preferably, the temperature of the reaction in step (3) is 20 - 30 °C, and the reaction time is 1 - 3 h.

[0022] Preferably, the particle size of the silica powder in step (4) is 50 - 200 nm;

[0023] The mass ratio of the modified quantum dots to the silica powder in step (4) is 1:8 - 12;

[0024] The temperature of the reaction in step (4) is 20 - 60 °C, and the reaction time is 1 - 3 h.

[0025] Preferably, the binder in step (5) includes epoxy resin, polyurethane or acrylate;

[0026] The mass ratio of the modified silica powder to the binder in step (5) is 5 - 7:1.

[0027] The present invention also provides a highly efficient multicolor luminescent silica powder composite material modified by quantum dots prepared by the preparation method of the highly efficient multicolor luminescent silica powder composite material modified by quantum dots.

[0028] The present invention also provides the application of the highly efficient multicolor luminescent silica powder composite material modified by quantum dots in traffic signal lights or fire indicator lights.

[0029] The beneficial effects of the present invention are:

[0030] The present invention provides a preparation method of a highly efficient multicolor luminescent silica powder composite material modified by quantum dots, comprising the following steps: mixing a cadmium source solution and a selenium source solution and reacting to obtain CdSe quantum dots; mixing the CdSe quantum dots and a zinc source solution and reacting to obtain CdSe / ZnS quantum dots; mixing the CdSe / ZnS quantum dots, an organic solvent and a silanizing reagent and reacting to obtain modified quantum dots; mixing the modified quantum dots and silica powder and reacting to obtain modified silica powder; mixing the modified silica powder and a binder to obtain a highly efficient multicolor luminescent silica powder composite material modified by quantum dots. The present invention provides a highly efficient and multicolor luminescent silica powder composite material, which is applicable to traffic signal lights and fire indicator lights. It not only significantly improves the optoelectronic performance and environmental stability of the signal lights, but also enhances the visibility and safety of the signal lights through multicolor display and reflective performance enhancement, and has significant application prospects and economic benefits.

[0031] Specifically, the high-efficiency multi-color luminescent silicon micropowder composite material prepared by the present invention has the following advantages: (a) High-efficiency luminescence: The quantum dot material has a high quantum yield. Through the composite with silicon micropowder, the photoluminescence quantum yield can reach more than 55%; the high reflectivity of silicon micropowder further improves the luminescence efficiency of quantum dots, enabling the signal lamp to provide a high-brightness light source under low energy consumption conditions; (b) Excellent environmental stability: After surface modification, the stability of the quantum dot material is significantly improved, and it can resist the influence of harsh environments such as high temperature and high humidity; the coating of silicon micropowder further enhances the mechanical strength and weather resistance of the composite material. Under the conditions of a temperature of 85°C and a relative humidity of 85%, the light attenuation rate is only 20%, and the service life exceeds 5000 hours; (c) Multi-color display: By adjusting the size of quantum dots, multi-color luminescence from red to green is achieved, which enables the signal lamp to provide diverse color displays according to the requirements of different application scenarios, improving the visibility and recognition of the signal lamp; (d) Enhanced reflective performance: Silicon micropowder has a high refractive index and reflectivity, which can effectively reflect ambient light and improve the visibility of the sign in the case of the light source being turned off or insufficient light. Under emergency power outage conditions, silicon micropowder reflects and refracts weak light to achieve efficient display and ensure safety; (e) Long service life: The mechanical strength and wear resistance of the composite material are improved, and the service life is significantly extended, reducing the maintenance and replacement costs. Detailed implementation manners

[0032] The present invention provides a preparation method of a high-efficiency multi-color luminescent silicon micropowder composite material based on quantum dot modification, comprising the following steps:

[0033] (1) Mix a cadmium source solution and a selenium source solution and react to obtain CdSe quantum dots;

[0034] (2) Mix the CdSe quantum dots and a zinc source solution and react to obtain CdSe / ZnS quantum dots;

[0035] (3) Mix the CdSe / ZnS quantum dots, an organic solvent and a silanization reagent and react to obtain modified quantum dots;

[0036] (4) Mix the modified quantum dots and silicon micropowder and react to obtain modified silicon micropowder;

[0037] (5) Mix the modified silicon micropowder and a binder to obtain the high-efficiency multi-color luminescent silicon micropowder composite material based on quantum dot modification.

[0038] In the present invention, the cadmium source in the cadmium source solution in step (1) preferably includes cadmium oxide, cadmium acetate or cadmium chloride; the solvent of the cadmium source solution preferably includes oleylamine (CAS No. 112-90-3) or oleic acid (CAS No. 112-80-1); the concentration of the cadmium source solution is preferably 0.1 - 0.2 mol / L, more preferably 0.12 - 0.18 mol / L, and still more preferably 0.15 mol / L.

[0039] In the present invention, the selenium source in the selenium source solution in step (1) preferably includes selenium powder or hydrogen selenide; the solvent of the selenium source solution preferably includes trioctylphosphine (CAS No. 4731-53-7) or oleylamine; the concentration of the selenium source solution is preferably 0.1 - 0.15 mol / L, more preferably 0.11 - 0.14 mol / L, and still more preferably 0.12 - 0.13 mol / L.

[0040] In the present invention, the molar ratio of the cadmium source in the cadmium source solution to the selenium source in the selenium source solution in step (1) is preferably 1 - 2:1, more preferably 1.2 - 1.8:1, and still more preferably 1.5 - 1.6:1.

[0041] In the present invention, the temperature of the reaction in step (1) is preferably 180 - 220 °C, more preferably 190 - 210 °C, and still more preferably 200 °C; the reaction time is preferably 20 - 40 min, more preferably 25 - 35 min, and still more preferably 30 min.

[0042] In the present invention, after the reaction in step (1) is completed, post-treatment is carried out to ensure that the obtained CdSe quantum dots have high purity and high stability; the post-treatment preferably includes the following steps: naturally cooling the system, then adding a precipitating agent to cause precipitation of the quantum dots, performing centrifugal separation after precipitation, washing the sample obtained by centrifugal separation to remove unreacted precursors and residual solvents, and obtaining CdSe quantum dots after washing; performing vacuum drying on the CdSe quantum dots to facilitate further processing of the CdSe quantum dots; or dispersing the CdSe quantum dots in an organic solvent for storage to ensure good dispersibility of the CdSe quantum dots.

[0043] In the present invention, the target temperature for natural cooling is preferably 20 - 25°C, more preferably 21 - 24°C, and even more preferably 22 - 23°C; the precipitating agent preferably includes ethanol or acetone; the amount of the precipitating agent can be determined by conventional technical means in the art; the rotation speed for centrifugal separation is preferably 6000 - 10000 r / min, more preferably 7000 - 9000 r / min, and even more preferably 8000 r / min; the time for centrifugal separation is preferably 10 - 15 min, more preferably 11 - 14 min, and even more preferably 12 - 13 min; the washing reagent preferably includes ethanol or n-hexane; the number of washing times is preferably ≥2 times, more preferably ≥3 times, and even more preferably ≥4 times; the temperature for vacuum drying is preferably 40 - 60°C, more preferably 45 - 55°C, and even more preferably 50°C; the time for vacuum drying can be determined by conventional technical means in the art; the organic solvent preferably includes n-hexane, toluene or chloroform.

[0044] In the present invention, the zinc source in the zinc source solution in step (2) preferably includes zinc acetate or zinc chloride; the solvent of the zinc source solution preferably includes oleylamine or oleic acid; the concentration of the zinc source solution is preferably 0.1 - 0.15 mol / L, more preferably 0.11 - 0.14 mol / L, and even more preferably 0.12 - 0.13 mol / L.

[0045] In the present invention, the molar ratio of the CdSe quantum dots to the zinc source in the zinc source solution in step (2) is preferably 1.5 - 2:1, more preferably 1.6 - 1.9:1, and even more preferably 1.7 - 1.8:1; at the specific molar ratio in the present invention, it can ensure that the ZnS shell fully covers the CdSe core and provides sufficient stability and luminescence efficiency.

[0046] In the present invention, the temperature of the reaction in step (2) is preferably 180 - 220°C, more preferably 190 - 210°C, and even more preferably 200°C; the time of the reaction is preferably 20 - 40 min, more preferably 25 - 35 min, and even more preferably 30 min.

[0047] In the present invention, after the reaction in step (2) is completed, post-treatment is carried out to ensure that the CdSe quantum dots react completely with the zinc source and form a stable ZnS shell, ensuring that the obtained quantum dots have high purity and high stability; the post-treatment preferably includes the following steps: rapidly cooling the system to terminate the reaction and prevent excessive growth of the quantum dots; then adding a precipitating agent to cause the quantum dots to precipitate, and after the precipitation is completed, centrifugal separation is carried out, and the sample obtained by centrifugal separation is washed to remove unreacted precursors and residual solvents, and CdSe / ZnS quantum dots are obtained after the washing is completed; the CdSe / ZnS quantum dots are vacuum-dried to facilitate the next treatment of the CdSe / ZnS quantum dots; or the CdSe / ZnS quantum dots are dispersed in an organic solvent for storage to ensure good dispersibility of the CdSe / ZnS quantum dots.

[0048] In the present invention, the target temperature for rapid cooling is preferably 20-25 °C, more preferably 21-24 °C, and even more preferably 22-23 °C; the precipitating agent preferably includes ethanol or acetone; the dosage of the precipitating agent can be determined by conventional technical means in the art; the rotation speed for centrifugal separation is preferably 6000-10000 r / min, more preferably 7000-9000 r / min, and even more preferably 8000 r / min; the time for centrifugal separation is preferably 10-15 min, more preferably 11-14 min, and even more preferably 12-13 min; the washing reagent preferably includes ethanol or n-hexane; the number of washing times is preferably ≥2 times, more preferably ≥3 times, and even more preferably ≥4 times; the temperature for vacuum drying is preferably 40-60 °C, more preferably 45-55 °C, and even more preferably 50 °C; the time for vacuum drying can be determined by conventional technical means in the art; the organic solvent preferably includes n-hexane, toluene or chloroform.

[0049] In the present invention, the CdSe / ZnS quantum dots obtained by the reaction in step (2) have a CdSe core and a ZnS shell, and the formation of the ZnS shell can further improve the stability and luminescence efficiency of the quantum dots.

[0050] In the present invention, by adjusting the size of the CdSe / ZnS quantum dots, luminescence of different colors can be achieved; among them, when the quantum dot size is 1-2.8 nm, blue light is emitted, and the emission wavelength is 450-470 nm; when the quantum dot size is 3-3.8 nm, green light is emitted, and the emission wavelength is 520-540 nm; when the quantum dot size is 4-6 nm, red light is emitted, and the emission wavelength is 630-650 nm.

[0051] In the present invention, the size of CdSe / ZnS quantum dots is affected by the following factors: (a) reaction temperature: the higher the temperature, the faster the core growth, and the larger the generated quantum dots; (b) reaction time: extending the reaction time allows the core to continue growing, forming larger quantum dots; (c) precursor concentration: a higher precursor concentration helps accelerate the growth of the core, thereby generating quantum dots with a larger size, while a lower precursor concentration will generate smaller quantum dots; (d) reaction solvent: the type and concentration of solvents such as oleic acid and oleylamine affect the growth rate of the core.

[0052] In the present invention, the organic solvent described in step (3) preferably includes n-hexane, toluene or chloroform; the silanizing agent preferably includes 3-mercaptopropyltrimethoxysilane, aminopropyltriethoxysilane, phenyltriethoxysilane or trimethoxysilane.

[0053] In the present invention, the mass-volume ratio of the CdSe / ZnS quantum dots, the organic solvent and the silanizing agent described in step (3) is preferably 1 kg: 20-40 L: 0.2-0.5 L, more preferably 1 kg: 25-35 L: 0.25-0.45 L, and still more preferably 1 kg: 30 L: 0.3-0.4 L.

[0054] In the present invention, the temperature of the reaction described in step (3) is preferably 20-30 °C, more preferably 22-28 °C, and still more preferably 25 °C; the reaction time is preferably 1-3 h, more preferably 1.5-2.5 h, and still more preferably 2 h.

[0055] In the present invention, after the reaction in step (3) is completed, post-treatment is carried out to ensure that the product has high purity and high stability; the post-treatment preferably includes the following steps: allowing the system to cool naturally to prevent degradation or side reactions of the product; then adding a precipitating agent to promote precipitation of the material, and after precipitation is completed, centrifugal separation is carried out. The sample obtained by centrifugal separation is washed to remove residual impurities and ensure the purity of the product. After washing, modified quantum dots are obtained; the modified quantum dots are vacuum dried to facilitate further processing of the modified quantum dots; or the modified quantum dots are dispersed in an organic solvent for storage to ensure good dispersibility of the modified quantum dots.

[0056] In the present invention, the target temperature for natural cooling is preferably 20 - 25°C, more preferably 21 - 24°C, and even more preferably 22 - 23°C; the precipitant preferably includes ethanol or acetone; the amount of the precipitant can be determined by conventional technical means in the art; the rotation speed for centrifugal separation is preferably 6000 - 8000 r / min, more preferably 6500 - 7500 r / min, and even more preferably 7000 r / min; the time for centrifugal separation is preferably 10 - 15 min, more preferably 11 - 14 min, and even more preferably 12 - 13 min; the washing reagent preferably includes ethanol or n - hexane; the number of washing times is preferably ≥2 times, more preferably ≥3 times, and even more preferably ≥4 times; the temperature for vacuum drying is preferably 40 - 50°C, more preferably 43 - 47°C, and even more preferably 45°C; the time for vacuum drying can be determined by conventional technical means in the art; the organic solvent preferably includes n - hexane, toluene or chloroform.

[0057] In the present invention, the surface of the modified quantum dots obtained by the reaction in step (3) has thiol groups and can react with silicon micropowder subsequently.

[0058] In the present invention, the particle size of the silicon micropowder in step (4) is preferably 50 - 200 nm, more preferably 100 - 150 nm, and even more preferably 120 nm.

[0059] In the present invention, the mass ratio of the modified quantum dots to the silicon micropowder in step (4) is preferably 1:8 - 12, more preferably 1:9 - 11, and even more preferably 1:10.

[0060] In the present invention, the stirring speed for mixing in step (4) is preferably 400 - 600 r / min, more preferably 450 - 550 r / min, and even more preferably 500 r / min; the temperature for the reaction is preferably 20 - 60°C, more preferably 30 - 50°C, and even more preferably 40°C; the reaction time is preferably 1 - 3 h, more preferably 1.5 - 2.5 h, and even more preferably 2 h.

[0061] In the present invention, the binder in step (5) preferably includes epoxy resin, polyurethane or acrylate.

[0062] In the present invention, the mass ratio of the modified silicon micropowder to the binder in step (5) is preferably 5 - 7:1, more preferably 5.5 - 6.5:1, and even more preferably 6:1.

[0063] The present invention also provides a highly efficient multicolor luminescent silicon micropowder composite material modified by quantum dots prepared by the preparation method of the highly efficient multicolor luminescent silicon micropowder composite material modified by quantum dots described above.

[0064] In the present invention, the photoluminescence quantum yield of the high-efficiency multicolor luminescent silicon micropowder composite material modified with quantum dots reaches more than 50%, the luminescence wavelength is 520 - 540 nm, the full width at half maximum (FWHM) of luminescence is 25 - 30 nm, and the reflectivity reaches more than 92%.

[0065] In the present invention, the high-efficiency multicolor luminescent silicon micropowder composite material modified with quantum dots is encapsulated by a transparent polycarbonate material to protect it from environmental factors (such as humidity, temperature, and ultraviolet rays). The measured transmittance reaches more than 90%, and the ultraviolet radiation resistance intensity exceeds 1500 h.

[0066] In the present invention, the high-efficiency multicolor luminescent silicon micropowder composite material modified with quantum dots has a light attenuation rate of only 20% under the conditions of a temperature of 85°C and a relative humidity of 85%, and the service life exceeds 5000 h.

[0067] The present invention also provides the application of the high-efficiency multicolor luminescent silicon micropowder composite material modified with quantum dots in traffic signal lights or fire indicator lights.

[0068] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0069] Example 1

[0070] A cadmium source solution with a concentration of 0.1 mol / L (the cadmium source is cadmium acetate and the solvent is oleylamine) and a selenium source solution with a concentration of 0.1 mol / L (the selenium source is selenium powder and the solvent is trioctylphosphine) are mixed. The molar ratio of the cadmium source in the cadmium source solution to the selenium source in the selenium source solution is 1.5:1, and the reaction is carried out at 200°C for 30 min; after the reaction is completed, the system is naturally cooled to 25°C, then ethanol is added, and after precipitation, centrifugal separation is carried out at 8000 r / min for 12 min. The sample obtained by centrifugal separation is washed 3 times with ethanol and then vacuum dried at 50°C for 12 h to obtain CdSe quantum dots;

[0071] The above-mentioned CdSe quantum dots and a zinc source solution with a concentration of 0.1 mol / L (the zinc source is zinc acetate and the solvent is oleylamine) are mixed. The molar ratio of the CdSe quantum dots to the zinc source in the zinc source solution is 1.7:1, and the reaction is carried out at 200°C for 30 min; after the reaction is completed, the system is quickly cooled to 25°C by an ice-water bath, then acetone is added, and after precipitation, centrifugal separation is carried out at 8000 r / min for 12 min. The sample obtained by centrifugal separation is washed 3 times with n-hexane and then vacuum dried at 50°C for 12 h to obtain CdSe / ZnS quantum dots (with a size of 2.5 nm, emitting blue light, and the wavelength is 450 - 470 nm);

[0072] Mix CdSe / ZnS quantum dots, n-hexane, and 3-mercaptopropyltrimethoxysilane. The mass-volume ratio of CdSe / ZnS quantum dots, organic solvent, and silanizing reagent is 1 kg: 20 L: 0.2 L. React at 25 °C for 2 h. After the reaction, naturally cool the system to 25 °C, then add ethanol. After precipitation, centrifuge at 7000 r / min for 12 min. Wash the sample obtained by centrifugation with ethanol three times, and then vacuum dry at 45 °C for 12 h to obtain modified quantum dots.

[0073] Mix the modified quantum dots and silica powder with a particle size of 120 nm. The mass ratio of the modified quantum dots to the silica powder is 1:10. React at a rotation speed of 500 r / min and a temperature of 25 °C for 2 h to obtain modified silica powder.

[0074] Mix the modified silica powder and epoxy resin. The mass ratio of the modified silica powder to the binder is 6:1 to obtain a (blue) high-efficiency multicolor luminescent silica powder composite modified by quantum dots.

[0075] Example 2

[0076] Mix a cadmium source solution with a concentration of 0.12 mol / L (the cadmium source is cadmium acetate and the solvent is oleylamine) and a selenium source solution with a concentration of 0.1 mol / L (the selenium source is selenium powder and the solvent is trioctylphosphine). The molar ratio of the cadmium source in the cadmium source solution to the selenium source in the selenium source solution is 1.6:1. React at 200 °C for 30 min. After the reaction, naturally cool the system to 23 °C, then add acetone. After precipitation, centrifuge at 7000 r / min for 14 min. Wash the sample obtained by centrifugation with ethanol four times, and then vacuum dry at 55 °C for 12 h to obtain CdSe quantum dots.

[0077] Mix the above CdSe quantum dots with a zinc source solution with a concentration of 0.12 mol / L (the zinc source is zinc acetate and the solvent is oleylamine). The molar ratio of the CdSe quantum dots to the zinc source in the zinc source solution is 1.8:1. React at 200 °C for 30 min. After the reaction, quickly cool the system to 22 °C by an ice-water bath, then add ethanol. After precipitation, centrifuge at 7500 r / min for 13 min. Wash the sample obtained by centrifugation with n-hexane four times, and then vacuum dry at 50 °C for 12 h to obtain CdSe / ZnS quantum dots (with a size of 3.5 nm, emitting green light, and a wavelength of 520 - 540 nm).

[0078] Mix CdSe / ZnS quantum dots, n-hexane, and aminopropyltriethoxysilane. The mass-volume ratio of CdSe / ZnS quantum dots, organic solvent, and silanizing reagent is 1 kg: 20 L: 0.3 L, and react at 25 °C for 2 h. After the reaction, naturally cool the system to 23 °C, then add acetone. After precipitation, centrifuge at 6500 r / min for 14 min. Wash the sample obtained by centrifugation with ethanol 4 times, and then vacuum dry at 43 °C for 12 h to obtain modified quantum dots.

[0079] Mix the modified quantum dots and silica powder with a particle size of 120 nm. The mass ratio of the modified quantum dots to the silica powder is 1:12, and react at a rotation speed of 600 r / min and a temperature of 25 °C for 2 h to obtain modified silica powder.

[0080] Mix the modified silica powder and a binder (epoxy resin). The mass ratio of the modified silica powder to the binder is 6:1 to obtain a (green) high-efficiency multicolor luminescent silica powder composite based on quantum dot modification.

[0081] Example 3

[0082] Mix a cadmium source solution with a concentration of 0.1 mol / L (the cadmium source is cadmium chloride and the solvent is oleylamine) and a selenium source solution with a concentration of 0.12 mol / L (the selenium source is selenium powder and the solvent is trioctylphosphine). The molar ratio of the cadmium source in the cadmium source solution to the selenium source in the selenium source solution is 1.7:1, and react at 200 °C for 30 min. After the reaction, naturally cool the system to 24 °C, then add acetone. After precipitation, centrifuge at 7500 r / min for 13 min. Wash the sample obtained by centrifugation with ethanol 4 times, and then vacuum dry at 48 °C for 12 h to obtain CdSe quantum dots.

[0083] Mix the above CdSe / ZnS quantum dots and a zinc source solution with a concentration of 0.12 mol / L (the zinc source is zinc chloride and the solvent is oleylamine). The molar ratio of the CdSe / ZnS quantum dots to the zinc source in the zinc source solution is 1.9:1, and react at 200 °C for 30 min. After the reaction, quickly cool the system to 21 °C by an ice-water bath, then add ethanol. After precipitation, centrifuge at 7000 r / min for 14 min. Wash the sample obtained by centrifugation with n-hexane 3 times, and then vacuum dry at 52 °C for 12 h to obtain CdSe / ZnS quantum dots (with a size of 5.0 nm, emitting red light, and a wavelength of 630 - 650 nm).

[0084] Mix CdSe / ZnS quantum dots, n-hexane, and phenyltriethoxysilane. The mass-volume ratio of CdSe / ZnS quantum dots, organic solvent, and silanizing agent is 1 kg: 20 L: 0.25 L. React at 25 °C for 2 h. After the reaction, naturally cool the system to 24 °C, then add acetone. After precipitation, centrifuge at 6800 r / min for 15 min. Wash the sample obtained by centrifugation 4 times with ethanol, and then vacuum dry at 46 °C for 12 h to obtain modified quantum dots.

[0085] Mix the modified quantum dots and silica powder with a particle size of 150 nm. The mass ratio of the modified quantum dots to the silica powder is 1:12. React at a rotation speed of 500 r / min and a temperature of 25 °C for 2 h to obtain modified silica powder.

[0086] Mix the modified silica powder and a binder (epoxy resin). The mass ratio of the modified silica powder to the binder is 6:1 to obtain a highly efficient multicolor luminescent silica powder composite based on quantum dot modification (red).

[0087] Example 4

[0088] Mix a cadmium source solution with a concentration of 0.11 mol / L (the cadmium source is cadmium chloride and the solvent is oleylamine) and a selenium source solution with a concentration of 0.1 mol / L (the selenium source is selenium powder and the solvent is trioctylphosphine). The molar ratio of the cadmium source in the cadmium source solution to the selenium source in the selenium source solution is 1.8:1. React at 200 °C for 30 min. After the reaction, naturally cool the system to 22 °C, then add ethanol. After precipitation, centrifuge at 8500 r / min for 11 min. Wash the sample obtained by centrifugation 3 times with n-hexane, and then vacuum dry at 52 °C for 12 h to obtain CdSe quantum dots.

[0089] Mix the above CdSe / ZnS quantum dots and a zinc source solution with a concentration of 0.12 mol / L (the zinc source is zinc chloride and the solvent is oleylamine). The molar ratio of the CdSe / ZnS quantum dots to the zinc source in the zinc source solution is 1.8:1. React at 200 °C for 30 min. After the reaction, quickly cool the system to 20 °C by an ice-water bath, then add acetone. After precipitation, centrifuge at 7200 r / min for 14 min. Wash the sample obtained by centrifugation 4 times with ethanol, and then vacuum dry at 49 °C for 12 h to obtain CdSe / ZnS quantum dots (with a size of 4.5 nm, emitting red light, and a wavelength of 630 - 650 nm).

[0090] Mix CdSe / ZnS quantum dots, toluene, and 3-mercaptopropyltrimethoxysilane. The mass-volume ratio of CdSe / ZnS quantum dots, organic solvent, and silanizing agent is 1 kg: 25 L: 0.3 L, and react at 25 °C for 2 h; after the reaction, naturally cool the system to 21 °C, then add ethanol, and after precipitation, centrifuge at 6700 r / min for 13 min. Wash the sample obtained by centrifugation three times with n-hexane, and then vacuum dry at 44 °C for 12 h to obtain modified quantum dots;

[0091] Mix the modified quantum dots and silica powder with a particle size of 120 nm. The mass ratio of the modified quantum dots to the silica powder is 1:10, and react at a rotation speed of 500 r / min and a temperature of 25 °C for 2 h to obtain modified silica powder;

[0092] Mix the modified silica powder and polyurethane. The mass ratio of the modified silica powder to the binder is 6:1 to obtain a (red) highly efficient multicolor luminescent silica powder composite based on quantum dot modification.

[0093] Example 5

[0094] Mix a cadmium source solution with a concentration of 0.14 mol / L (the cadmium source is cadmium acetate and the solvent is oleylamine) and a selenium source solution with a concentration of 0.11 mol / L (the selenium source is selenium powder and the solvent is trioctylphosphine). The molar ratio of the cadmium source in the cadmium source solution to the selenium source in the selenium source solution is 1.7:1, and react at 200 °C for 30 min; after the reaction, naturally cool the system to 21 °C, then add acetone, and after precipitation, centrifuge at 7800 r / min for 10 min. Wash the sample obtained by centrifugation four times with ethanol, and then vacuum dry at 47 °C for 12 h to obtain CdSe quantum dots;

[0095] Mix the above CdSe / ZnS quantum dots and a zinc source solution with a concentration of 0.15 mol / L (the zinc source is zinc acetate and the solvent is oleylamine). The molar ratio of the CdSe / ZnS quantum dots to the zinc source in the zinc source solution is 1.9:1, and react at 200 °C for 30 min; after the reaction, quickly cool the system to 19 °C through an ice-water bath, then add ethanol, and after precipitation, centrifuge at 7200 r / min for 15 min. Wash the sample obtained by centrifugation three times with n-hexane, and then vacuum dry at 53 °C for 12 h to obtain CdSe / ZnS quantum dots (with a size of 4.5 nm, emitting red light, and a wavelength of 630 - 650 nm);

[0096] Mix CdSe / ZnS quantum dots, n-hexane, and phenyltriethoxysilane. The mass-volume ratio of CdSe / ZnS quantum dots, n-hexane, and phenyltriethoxysilane is 1 kg: 20 L: 0.3 L, and react at 25 °C for 2 h. After the reaction, naturally cool the system to 20 °C, then add acetone. After precipitation, centrifuge at 6600 r / min for 12 min. Wash the sample obtained by centrifugation 4 times with ethanol, and then vacuum dry at 42 °C for 12 h to obtain modified quantum dots.

[0097] Mix the modified quantum dots and silica powder with a particle size of 120 nm. The mass ratio of the modified quantum dots to the silica powder is 1:10, and react at a rotation speed of 500 r / min and a temperature of 25 °C for 2 h to obtain modified silica powder.

[0098] Mix the modified silica powder and epoxy resin. The mass ratio of the modified silica powder to the epoxy resin is 6:1 to obtain a (red) high-efficiency multicolor luminescent silica powder composite material modified with quantum dots.

[0099] Performance Test

[0100] Perform optical performance tests on the high-efficiency multicolor luminescent silica powder composite materials obtained in Examples 1 to 5, and detect their environmental stability at 85 °C / 85% humidity. The results are shown in Table 1.

[0101] Table 1 Performance Test Results of Luminescent Silica Powder Composite Materials in Examples 1 to 5

[0102]

[0103]

[0104] As can be seen from Table 1, the high-efficiency multicolor luminescent silica powder composite material prepared in the present invention has a photoluminescence quantum yield of over 55%; the full width at half maximum (FWHM) of luminescence is below 28 nm, the reflectivity is above 92%, and the transmittance is above 90%; under the conditions of a temperature of 85 °C and a relative humidity of 85%, the light attenuation rate is below 20%, and the service life exceeds 5000 h. This shows that the high-efficiency multicolor luminescent silica powder composite material prepared in the present invention has the characteristics of high-efficiency luminescence, multicolor display, long life, excellent reflective performance, and environmental stability, and is suitable for traffic signal lights and fire indicator lights, which can improve their visibility and safety.

[0105] As can be seen from the above embodiments, the present invention provides a method for preparing a high-efficiency multicolor luminescent silicon micropowder composite material modified with quantum dots, comprising the following steps: mixing a cadmium source solution and a selenium source solution and reacting to obtain CdSe quantum dots; mixing the CdSe quantum dots and a zinc source solution and reacting to obtain CdSe / ZnS quantum dots; mixing the CdSe / ZnS quantum dots, an organic solvent and a silanizing reagent and reacting to obtain modified quantum dots; mixing the modified quantum dots and silicon micropowder and reacting to obtain modified silicon micropowder; and mixing the modified silicon micropowder and a binder to obtain a high-efficiency multicolor luminescent silicon micropowder composite material modified with quantum dots. The present invention provides a high-efficiency and multicolor luminescent silicon micropowder composite material, which is applicable to traffic signal lights and fire indicator lights. It not only significantly improves the optoelectronic performance and environmental stability of the signal lights, but also enhances the visibility and safety of the signal lights through multicolor display and enhanced reflective performance, and has significant application prospects and economic benefits.

[0106] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of an efficient multicolor luminescent silicon micropowder composite material based on quantum dot modification, characterized in that, It includes the following steps: (1) Mix a cadmium source solution and a selenium source solution and carry out a reaction to obtain CdSe quantum dots; (2) Mix the CdSe quantum dots and a zinc source solution and carry out a reaction to obtain CdSe / ZnS quantum dots; (3) Mix the CdSe / ZnS quantum dots, an organic solvent and a silanizing reagent and carry out a reaction to obtain modified quantum dots; (4) Mix the modified quantum dots and silica powder and carry out a reaction to obtain modified silica powder; (5) Mix the modified silica powder and a binder to obtain the high-efficiency multicolor luminescent silica powder composite material modified with quantum dots as described.

2. The preparation method of the high-efficiency multicolor luminescent silicon micro powder composite material modified by quantum dots according to claim 1, characterized in that, In step (1), the cadmium source in the cadmium source solution includes cadmium oxide, cadmium acetate or cadmium chloride; the solvent of the cadmium source solution includes oleylamine or oleic acid; the concentration of the cadmium source solution is 0.1 - 0.2 mol / L; In step (1), the selenium source in the selenium source solution includes selenium powder or hydrogen selenide; the solvent of the selenium source solution includes trioctylphosphine or oleylamine; the concentration of the selenium source solution is 0.1 - 0.15 mol / L; In step (1), the molar ratio of the cadmium source in the cadmium source solution to the selenium source in the selenium source solution is 1 - 2:

1.

3. The preparation method of the high-efficiency multicolor luminescent silicon micropowder composite material based on quantum dot modification according to claim 1 or 2, characterized in that, In step (1), the temperature of the reaction is 180 - 220 °C, and the reaction time is 20 - 40 min.

4. The preparation method of the high-efficiency multicolor luminescent silicon micropowder composite material modified by quantum dots according to claim 3, characterized in that, In step (2), the zinc source in the zinc source solution includes zinc acetate or zinc chloride; the solvent of the zinc source solution includes oleylamine or oleic acid; the concentration of the zinc source solution is 0.1 - 0.15 mol / L; In step (2), the molar ratio of the CdSe quantum dots to the zinc source in the zinc source solution is 1.5 - 2:1; In step (2), the temperature of the reaction is 180 - 220 °C, and the reaction time is 20 - 40 min.

5. The preparation method of the high-efficiency multicolor luminescent silicon micropowder composite material modified by quantum dots according to claim 4, characterized in that, In step (3), the organic solvent includes n-hexane, toluene or chloroform; the silanizing reagent includes 3-mercaptopropyltrimethoxysilane, aminopropyltriethoxysilane, phenyltriethoxysilane or trimethoxysilane; In step (3), the mass-to-volume ratio of the CdSe / ZnS quantum dots, the organic solvent and the silanizing reagent is 1 kg:20 - 40 L:0.2 - 0.5 L.

6. The preparation method of the high-efficiency multicolor luminescent silicon micro-powder composite material modified based on quantum dots according to claim 5, characterized in that In step (3), the temperature of the reaction is 20 - 30 °C, and the reaction time is 1 - 3 h.

7. The preparation method of the high-efficiency multicolor luminescent silicon micropowder composite material based on quantum dot modification according to claim 5 or 6, characterized in that, In step (4), the particle size of the silica powder is 50 - 200 nm; In step (4), the mass ratio of the modified quantum dots to the silica powder is 1:8 - 12; In step (4), the temperature of the reaction is 20 - 60 °C, and the reaction time is 1 - 3 h.

8. The preparation method of the high-efficiency multicolor light-emitting silicon micropowder composite material based on quantum dot modification according to claim 7, characterized in that, In step (5), the binder includes epoxy resin, polyurethane or acrylate; In step (5), the mass ratio of the modified silica powder to the binder is 5 - 7:

1.

9. The high-efficiency multicolor luminescent silica powder composite material modified with quantum dots prepared by the preparation method of the high-efficiency multicolor luminescent silica powder composite material modified with quantum dots according to any one of claims 1 - 8.

10. Application of the high-efficiency multicolor luminescent silica powder composite material modified with quantum dots according to claim 9 in traffic signal lights or fire indicator lights.

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