Silicate fluorescent micro-ceramic glass with precipitated carbon dots and preparation method thereof
By smelting the silicate fluorescent microcrystalline glass under a reducing carbon source atmosphere, precipitating carbon dots and maintaining transparency, the stability of carbon dots in large-size applications is solved, and its application in the fields of lighting display and anti-counterfeiting is expanded.
Patent Information
- Application Number
- CN202411226502.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-03
- Publication Date
- 2025-09-02
- Estimated Expiration
- 2044-09-03
AI Technical Summary
In the prior art, carbon dot fluorescent materials are mainly in the form of solutions or powders, lacking bulk large-sized materials, and carbon materials are easily combustible at high temperatures, which limits their application in the field of large-size lighting displays; traditional high-temperature heat treatment methods can easily lead to a decrease in transmittance, limiting the application of oxyfluoroglass glass.
The silicate network structure containing fluorescent microcrystalline glass raw materials was prepared by melting the reducing carbon source in the atmosphere. The carbon dots were precipitated in the glass through high temperature smelting, and the coating effect of the silicate network on the carbon dots was used to improve its stability.
It achieves excellent transparency while precipitating carbon dots in glass, and expands the application prospects of carbon dot materials in large-size lighting displays, LED lighting displays, anti-counterfeiting and other fields.
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Figure CN119059734B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of rare earth luminescent materials, and in particular to a silicate fluorescent microcrystalline glass with precipitated carbon dots and a preparation method thereof. Background Art
[0002] Fluorescent glass-ceramics is a composite material of luminescent crystals and glass materials. Today, the most studied fluorescent glass-ceramics is oxyfluoride glass-ceramics, which has the advantages of low phonon energy of fluoride crystals and the high physical and chemical stability of oxide glass, and has been widely studied and applied. The traditional method of preparing fluorescent glass-ceramics is usually to first prepare a base glass through special component design, and then precipitate the crystals in situ in the glass through constant temperature heat treatment, thereby obtaining a composite material of crystals and glass. However, oxyfluoride glass-ceramics prepared by subsequent high-temperature heat treatment can easily lead to a decrease in transmittance due to inaccurate heat treatment conditions, thereby limiting its application.
[0003] Carbon quantum dots, also known as C-dots, are a type of carbon-based, zero-dimensional material. Compared to other heavy metal semiconductor quantum dot materials, C-dots not only possess excellent luminescence properties but also possess excellent water solubility, environmental friendliness, and low cost. They hold great promise for applications in bioimaging, catalysis, display, and anti-counterfeiting. However, currently studied C-dot fluorescent materials are all solutions or phosphors containing C-dots, lacking bulk, large-scale C-dot materials, and thus have not yet expanded their application to large-scale lighting and display applications.
[0004] Because carbon materials typically burn easily at high temperatures, transforming into carbon monoxide or carbon dioxide, there have been no reports of precipitating carbon dots in glass through high-temperature melting and heat treatment. This has limited the development of carbon dot fluorescent glass-ceramics. Therefore, developing a feasible preparation method for carbon dot glass-ceramics is an urgent challenge facing existing technologies. Summary of the Invention
[0005] The present invention aims to provide a silicate fluorescent glass-ceramic with precipitated carbon dots and a method for preparing the same, thereby addressing the aforementioned problems in the background art. The novel silicate fluorescent glass-ceramic with precipitated carbon dots provided by the present invention has a simple preparation method, precipitates carbon dots in the glass while maintaining excellent transparency, and significantly improves the stability of the carbon dots due to the "encapsulation" effect of the silicate network on the precipitated carbon dots.
[0006] To achieve the above object, the present invention provides the following technical solutions:
[0007] One of the technical solutions of the present invention is to provide a fluorescent micro-ceramic glass with precipitated carbon dots, wherein the raw materials include fluorescent micro-ceramic glass raw materials and a reducing carbon source atmosphere;
[0008] The fluorescent glass-ceramic raw materials include, by mole,:
[0009] SiO2 35-55 parts, H3BO 35-20 parts, Na2CO3 5-15 parts, LuF3 3-10 parts, CeF3 1-5 parts and BaF2 10-20 parts.
[0010] Preferably, based on the total molar amount of SiO2, H3BO3, Na2CO3, LuF3, and BaF2 being 100%, the molar addition amount of CeF3 is 1 to 5% of the total molar amount of SiO2, H3BO3, Na2CO3, LuF3, and BaF2.
[0011] Preferably, the reducing carbon source atmosphere is a CO atmosphere.
[0012] The working principle of CeF3 as a color-producing fluorescent material has not been fully studied. Currently, only the variable valence state of the Ce element has been shown to be related. The present inventors' research found that even if CeF3 is replaced with rare earth fluoride raw materials such as EuF3, TbF3, GdF3, and TmF3, the original effect cannot be maintained.
[0013] The second technical solution of the present invention is to provide a method for preparing the fluorescent micro-ceramic glass with precipitated carbon dots, which is prepared by melting fluorescent micro-ceramic glass raw materials in a reducing carbon source atmosphere.
[0014] Preferably, the preparation method comprises the following steps:
[0015] SiO2, H3BO3, Na2CO3, LuF3, CeF3 and BaF2 are used as raw materials for fluorescent microcrystalline glass, mixed in proportion, and poured into a 20mL alumina crucible. Then, the crucible containing the raw materials for fluorescent microcrystalline glass is placed into a large alumina crucible with a capacity of 500mL and filled with carbon powder for smelting to obtain glass melt, which is then molded to obtain the fluorescent microcrystalline glass with precipitated carbon points.
[0016] The carbon powder here can create a carbon reducing atmosphere and is also the carbon source of carbon quantum dots.
[0017] Preferably, the mixing is carried out by grinding in an agate mortar for 30 minutes.
[0018] Preferably, the smelting temperature is 1480° C. and the smelting time is 45 minutes.
[0019] Preferably, the forming process comprises the following steps:
[0020] The molten glass is poured into a room temperature mold, and another room temperature iron plate is used to press-cast the molten glass into bulk glass.
[0021] The beneficial technical effects of the present invention are as follows:
[0022] The preparation method of the novel silicate fluorescent microcrystalline glass with precipitated carbon dots provided by the present invention is simple, and excellent transparency is maintained while precipitating carbon dots in the glass. In addition, the stability of the carbon dots is greatly improved due to the "coating" effect of the silicate network structure on the precipitated carbon dots.
[0023] The fluorescent micro-ceramic glass provided by the present invention also has the advantage of adjustable shape and size, which can effectively expand the application field of carbon dot materials and show its application prospects in the field of large-scale lighting.
[0024] The present invention prepares microcrystalline glass containing carbon quantum dots by a high-temperature melting method for the first time. The preparation method of the microcrystalline glass is simple and convenient, and the color is adjustable, so it can be applied to LED lighting display, anti-counterfeiting and other fields. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0026] Figure 1 This is the emission spectrum of the product of Example 1 under 300nm ultraviolet light excitation.
[0027] Figure 2 This is the excitation spectrum of the product in Example 1 at a monitoring wavelength of 366 nm.
[0028] Figure 3 This is the emission spectrum of the product of Example 1 under 400nm violet light excitation.
[0029] Figure 4 This is the excitation spectrum of the product in Example 1 when the monitoring wavelength is 600 nm.
[0030] Figure 5 The transmission spectrum and actual photograph of the product of Example 1 in the range of 250-750nm.
[0031] Figure 6 This is the emission spectrum of the product of Comparative Example 1 under 400nm ultraviolet light excitation.
[0032] Figure 7 This is the emission spectrum of the product of Comparative Example 2 under 400nm ultraviolet light excitation. DETAILED DESCRIPTION
[0033] Various exemplary embodiments of the present invention are now described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention.
[0034] In addition, for numerical ranges in the present invention, it is understood that each intervening value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any stated value or stated range, and any other stated value or intervening value in the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.
[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention.
[0036] The terms “include,” “including,” “have,” “contain,” etc. used in the present invention are open-ended terms, meaning including but not limited to.
[0037] Unless otherwise specified, the "room temperature" in the present invention is 20-30°C.
[0038] The raw materials used in the following examples and comparative examples of the present invention are all commercially available products.
[0039] Example 1
[0040] Preparation of fluorescent glass-ceramics with precipitated carbon dots:
[0041] (1) Mixing the raw materials according to the following molar fractions to obtain fluorescent glass-ceramics raw materials:
[0042] SiO2 55 parts, H3BO3 10 parts, Na2CO3 15 parts, LuF3 10 parts, CeF3 1 part and BaF2 10 parts;
[0043] (2) Weigh 20 g of fluorescent microcrystalline glass raw material, put it into an agate mortar and grind it thoroughly for 30 minutes to mix the raw materials evenly, then pour it into a 30 mL alumina crucible, then put the crucible containing the fluorescent microcrystalline glass raw material into a large crucible with a capacity of 500 mL and 300 g of carbon powder, cover it with a mullite lid to seal it, and then place it in a silicon-molybdenum rod electric furnace at 1460°C and smelt it in a CO reducing atmosphere for 40 minutes, then quickly pour the glass melt into a cast iron mold at room temperature and cover it with another iron plate at room temperature, cool and shape it, cut, grind and polish it to make a fluorescent microcrystalline glass with precipitated carbon points of 10 mm × 10 mm × 1.5 mm in size.
[0044] Effect Verification 1
[0045] The product of Example 1 was tested for excitation spectrum and emission spectrum, and the test results are as follows: Figure 1 and Figure 2 shown.
[0046] Figure 1 This is the emission spectrum of the product of Example 1 under 300nm ultraviolet light excitation.
[0047] Figure 2 This is the excitation spectrum of the product in Example 1 at a monitoring wavelength of 366 nm.
[0048] Figure 3 This is the emission spectrum of the product of Example 1 under 400nm violet light excitation.
[0049] Figure 4 This is the excitation spectrum of the product in Example 1 when the monitoring wavelength is 600 nm.
[0050] Figure 5 The transmission spectrum and actual photograph of the product of Example 1 in the range of 250-750nm.
[0051] like Figure 1 As shown, under the excitation of 300nm ultraviolet light, the glass-ceramic emits a broadband spectrum with a peak at 366nm, which corresponds to Ce 3+ Energy level transition of ion 5d to 4f. Figure 2 This corresponds to Ce 3+ The energy level transition from ion 4f to 5d has a central wavelength of 300nm. Figure 3 The emission spectrum of the glass-ceramic under the excitation of light with a wavelength of 400nm is shown. Under this excitation condition, the glass-ceramic emits a broadband red light with a central wavelength of 600nm. Because there are no other red-emitting ions doped in this glass system, it can be determined that this red light is the emission of carbon quantum dots. The excitation spectrum was tested with a monitoring wavelength of 600nm, as shown in Figure 2. Figure 4As shown in Figure 2, the emission spectrum also presents a broadband spectrum centered at 400 nm. In addition, according to the transmittance spectrum and the actual photograph ( Figure 5 ) It can be seen that the glass-ceramics has high transparency. Figure 1-5 It can be seen that in this glass-ceramic system, carbon quantum dots and Ce 3+ The luminescence of the nanocrystals is independent of each other, which results in the glass-ceramics emitting different colors under different excitation wavelengths, which is expected to be applied in the field of optical anti-counterfeiting.
[0052] Example 2
[0053] Preparation of fluorescent glass-ceramics with precipitated carbon dots:
[0054] (1) Mixing the raw materials according to the following molar fractions to obtain fluorescent glass-ceramics raw materials:
[0055] SiO250 parts, H3BO315 parts, Na2CO315 parts, LuF35 parts, CeF32 parts and BaF215 parts;
[0056] (2) Weigh 20 g of fluorescent microcrystalline glass raw material, put it into an agate mortar and grind it thoroughly for 30 minutes to mix the raw materials evenly, then pour it into a 30 mL alumina crucible, then put the crucible containing the fluorescent microcrystalline glass raw material into a large crucible with a capacity of 500 mL and 300 g of carbon powder, cover it with a mullite lid to seal it, and then place it in a silicon-molybdenum rod electric furnace at 1480°C and smelt it in a CO reducing atmosphere for 40 minutes, then quickly pour the glass melt into a cast iron mold at room temperature and cover it with another iron plate at room temperature, cool and shape it, cut, grind and polish it to make fluorescent microcrystalline glass with precipitated carbon points of 10 mm × 10 mm × 1.5 mm in size.
[0057] Comparative Example 1 (Compared with Example 1, only the atmosphere was modified to 5 vol% H2-95 vol% N2)
[0058] Preparation of glass-ceramics:
[0059] (1) Mixing the raw materials according to the following molar fractions to obtain fluorescent glass-ceramics raw materials:
[0060] SiO2 55 parts, H3BO3 10 parts, Na2CO3 15 parts, LuF3 10 parts, CeF3 1 part and BaF2 10 parts;
[0061] (2) Weigh 20 g of fluorescent microcrystalline glass raw material, put it into an agate mortar and grind it thoroughly for 30 minutes to mix the raw materials evenly, then pour it into a 30 mL alumina crucible, then put the crucible containing the fluorescent microcrystalline glass raw material into a large crucible with a capacity of 500 mL and 300 g of carbon powder, cover it with a mullite lid to seal it, and then place it in a silicon-molybdenum rod electric furnace at 1460°C in a 5 vol% H2-95 vol% N2 mixed atmosphere to smelt for 40 minutes, then quickly pour the glass melt into a cast iron mold at room temperature and cover it with another iron plate at room temperature, cool and shape it, cut, grind and polish it to make microcrystalline glass with a size of 10 mm × 10 mm × 1.5 mm.
[0062] Effect Verification 2
[0063] The product of comparative example 1 was excited with 400nm light, and the test results were as follows: Figure 5 shown.
[0064] Figure 6 This is the emission spectrum of the product of Comparative Example 1 under 400nm ultraviolet light excitation.
[0065] like Figure 6 As shown, the glass does not emit broadband red light with a peak at 600 nm under the excitation of light with a wavelength of 400 nm. This is because no carbon element is introduced during the melting process and no carbon quantum dots are precipitated in the glass.
[0066] Comparative Example 2 (Compared with Example 1, only the atmosphere was changed to air)
[0067] Preparation of glass-ceramics:
[0068] (1) Mixing the raw materials according to the following molar fractions to obtain fluorescent glass-ceramics raw materials:
[0069] SiO2 55 parts, H3BO3 10 parts, Na2CO3 15 parts, LuF3 10 parts, CeF3 1 part and BaF2 10 parts;
[0070] (2) Weigh 20 g of fluorescent microcrystalline glass raw material, put it into an agate mortar and grind it thoroughly for 30 minutes to mix the raw materials evenly, then pour it into a 30 mL alumina crucible, then put the crucible containing the fluorescent microcrystalline glass raw material into a large crucible with a capacity of 500 mL and 300 g of carbon powder, cover it with a mullite lid to seal it, and then place it in a silicon-molybdenum rod electric furnace at 1460°C in an air atmosphere (air flow rate is...) and smelt it for 40 minutes, then quickly pour the glass melt into a cast iron mold at room temperature and cover it with another iron plate at room temperature, cool and shape it, cut, grind and polish it to make microcrystalline glass with a size of 10 mm × 10 mm × 1.5 mm.
[0071] Effect Verification 3
[0072] The product of comparative example 2 was excited with 400nm light, and the test results were as follows: Figure 6 shown.
[0073] Figure 7 This is the emission spectrum of the product of Comparative Example 2 under 400nm ultraviolet light excitation.
[0074] like Figure 7 As shown, under the excitation of light with a wavelength of 400nm, the glass does not emit broadband red light with a peak at 600nm. This is because no carbon element is introduced during the melting process and no carbon quantum dots are precipitated in the glass.
[0075] In combination with Example 1, Comparative Example 1 and Comparative Example 2, it can be determined that the microcrystalline glass with precipitated carbon quantum dots prepared by the present invention is formed when the carbon in the molten environment is "locked" in the glass network structure during the glass melting process. Compared with traditional oxyfluoride microcrystalline glass, this microcrystalline glass has precipitated carbon quantum dots without the need for subsequent heat treatment. In addition, compared to traditional carbon quantum dot materials, the carbon quantum dots in the microcrystalline glass prepared by the present invention emit red light with a central wavelength of 600nm under the excitation of light with a wavelength of 400nm.
[0076] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.
Claims
1. A fluorescent micro-ceramic glass with precipitated carbon dots, characterized in that: The raw materials include fluorescent micro-ceramic glass raw materials and reducing carbon source atmosphere; The fluorescent glass-ceramic raw materials include, by mole,: SiO2 35-55 parts, H3BO 35-20 parts, Na2CO3 5-15 parts, LuF3 3-10 parts, CeF3 1-5 parts and BaF2 10-20 parts.
2. The fluorescent glass-ceramics with precipitated carbon dots according to claim 1, characterized in that: The reducing carbon source atmosphere is a CO atmosphere.
3. A method for preparing the fluorescent glass-ceramics with precipitated carbon dots according to claim 1 or 2, characterized in that: It is made by melting fluorescent microcrystalline glass raw materials in a reducing carbon source atmosphere.
4. The preparation method according to claim 3, characterized in that The preparation method comprises the following steps: SiO2, H3BO3, Na2CO3, LuF3, CeF3 and BaF2 are used as raw materials for fluorescent microcrystalline glass, mixed in proportion, and poured into a 20mL alumina crucible. Then, the crucible containing the raw materials for fluorescent microcrystalline glass is placed into a large alumina crucible with a capacity of 500mL and filled with carbon powder for smelting to obtain glass melt, which is then molded to obtain the fluorescent microcrystalline glass with precipitated carbon points.
5. The preparation method according to claim 4, characterized in that The mixing method is grinding in an agate mortar for 30 minutes.
6. The preparation method according to claim 3 or 4, characterized in that The smelting temperature is 1480° C. and the smelting time is 45 minutes.
Citation Information
Patent Citations
Rare earth doped microcrystalline glass of precipitated beta-NaGdF4 nanocrystalline and preparation method thereof
CN102603194A
Rare-earth-doping-free cyan luminescent microcrystalline glass and preparation method thereof
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