A solar-excited Mn 2+ LiAlGeO4 long-lasting-glow germanosilicate fluorescent glass ceramics and its preparation method

Abstract

The present invention discloses a sunlight-excited Mn 2+ : LiAlGeO4 long afterglow germanium silicate fluorescent glass ceramics and its preparation method, belonging to the technical field of inorganic luminescent materials. 2+ The raw materials of LiAlGeO4 long afterglow germanosilicate fluorescent glass ceramics include, by molar parts, 30-50 parts of GeO2, 5-15 parts of SiO2, 5-10 parts of Al2O3, 10-30 parts of ZnO, 5-15 parts of Li2CO3, 5-10 parts of K2CO3 and 0.1 parts of MnCO3. The present invention uses germanosilicate glass as the base glass and precipitates trigonal LiAlGeO4 nanocrystals in the glass through constant temperature heat treatment. The Mn provided by the present invention 2+ :LiAlGeO4 long afterglow germanium silicate fluorescent glass ceramics use transition metal manganese as the luminescent center ion, which can reduce the preparation cost and protect rare earth resources; due to the presence of a large number of defects in the glass matrix, it can effectively capture the electrons in the excitation process and transfer them to Mn 2+ ,produce 4 T1→ 6 A1 transition emits a long green afterglow when excited by sunlight.

Description

Technical Field

[0001] The present invention relates to the technical field of inorganic luminescent materials, and in particular to a sunlight-excited Mn 2+ :LiAlGeO4 long afterglow germanosilicate fluorescent glass ceramics and its preparation method. Background Art

[0002] Long afterglow luminescence refers to the phenomenon that luminescent materials can continue to emit light after the excitation light source is turned off. Due to their unique luminescence properties, long afterglow luminescent materials are widely used in information storage, lighting, anti-counterfeiting and other fields. Currently, the long afterglow materials with excellent performance include SrAl2O4:Eu 2+ , Dy 3+ (green), Sr4Al 14 O 25 :Eu 2+ , Dy 3+ (blue), Sr2MgSi2O7:Eu 2+ , Dy 3 + (blue), Y2O2S:Eu 3+ (red), etc. Most reported long-lasting phosphors are rare earth ion-doped long-lasting phosphors. However, rare earths are non-renewable resources and unsuitable for large-scale applications. Therefore, the development of non-rare earth-doped long-lasting phosphors is of great significance.

[0003] Glass-ceramics, also known as microcrystalline glass, are composite materials composed of glass and nanocrystals. They combine the advantages of glass—excellent physical and chemical stability, ease of preparation and processing into various shapes, and ease of mass production—with the exceptional luminescence properties of crystalline materials, making them ideal luminescent matrix materials. Compared to long-lasting phosphors, long-lasting luminescent glass-ceramics offer greater physical and chemical stability, making them suitable for a wider range of applications. Long-lasting luminescent glass-ceramics that can be excited by sunlight offer significant advantages in outdoor information displays and hold great research value. Summary of the Invention

[0004] The purpose of the present invention is to provide a solar-excited Mn 2+ : LiAlGeO4 long afterglow germanosilicate fluorescent glass ceramics and its preparation method, in order to solve the above problems in the background technology. The present invention uses germanosilicate glass as the base glass, and precipitates LiAlGeO4 nanocrystals of trigonal phase in the glass through constant temperature heat treatment. The Mn provided by the present invention 2+ :LiAlGeO4 long afterglow germanium silicate fluorescent glass ceramics use transition metal manganese as the luminescent center ion, which can reduce the preparation cost and protect rare earth resources; due to the presence of a large number of defects in the glass matrix, it can effectively capture the electrons in the excitation process and transfer them to Mn 2+ ,produce4 T1→ 6 A1 transition, emitting a long green afterglow.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] One of the technical solutions of the present invention is to provide a Mn 2+ :LiAlGeO4 long afterglow germanium silicate fluorescent glass ceramics, raw materials by molar parts, including:

[0007] GeO2 30-50 parts, SiO2 5-15 parts, Al2O3 5-10 parts, ZnO 10-30 parts, Li2CO3 5-15 parts, K2CO3 5-10 parts and MnCO3 0.1 parts.

[0008] Preferably, based on the total molar amount of GeO2, SiO2, Al2O3, ZnO, Li2CO3 and K2CO3 as 100%, the added amount of MnCO3 is 0.1% of the total molar amount of GeO2, SiO2, Al2O3, ZnO, Li2CO3 and K2CO3.

[0009] The second technical solution of the present invention is to provide a Mn 2+ The preparation method of LiAlGeO4 long afterglow germanium silicate fluorescent glass ceramics comprises the following steps:

[0010] Mix the raw materials in proportion, smelt, shape, anneal, and heat treat to obtain the Mn 2+ :LiAlGeO4 long afterglow germanosilicate fluorescent glass ceramics.

[0011] Preferably, the mixing is carried out by grinding in an agate mortar for 30 minutes.

[0012] Preferably, the smelting temperature is 1350-1500° C., and the smelting time is 30-60 minutes.

[0013] Preferably, the forming process comprises the following steps:

[0014] The molten glass obtained after the melting operation is poured into a mold, and another mold is used to press-cast the molten glass into bulk glass.

[0015] Preferably, the annealing is performed at 450-500° C. for 2-4 hours.

[0016] Annealing can eliminate the internal stress in the glass system of the present invention.

[0017] Preferably, the heat treatment is performed by heating the temperature to 580-680° C. at a heating rate of 15° C. / min and keeping the temperature for 1-3 hours.

[0018] The third technical solution of the present invention is to provide a Mn 2+ :Application of LiAlGeO4 long afterglow germanium silicate fluorescent glass ceramics in outdoor night display field.

[0019] The beneficial technical effects of the present invention are as follows:

[0020] The fluorescent glass ceramics of the present invention use GeO2 and SiO2 as glass network forming oxides; Al2O3 as glass network intermediate oxides; ZnO, Li2O and K2O as network outer oxides; Mn 2+ The present invention uses germanium silicate glass as the base glass and precipitates LiAlGeO nanocrystals in a rhombohedral phase through constant-temperature heat treatment. The added SiO2 can be used to adjust the glass structure and aid in the heat treatment crystallization process. Under ultraviolet light excitation, it emits green light with a peak at 540nm, and even when the excitation light source is turned off, it still emits a green afterglow. Furthermore, this fluorescent glass-ceramic can be excited by sunlight to produce a long-lasting green afterglow.

[0021] The Mn provided by the present invention 2+ :LiAlGeO4 long afterglow germanium silicate fluorescent glass ceramics use transition metal manganese as the luminescent center ion, which can reduce the preparation cost and protect rare earth resources; due to the presence of a large number of defects in the glass matrix, the defects can effectively capture the electrons in the excitation process and transfer them to Mn 2+ ,produce 4 T1→ 6 A1 transition, emitting a long green afterglow.

[0022] The Mn provided by the present invention 2+ : LiAlGeO4 fluorescent glass ceramics can have long afterglow luminescence performance after being irradiated by sunlight, and this glass ceramic has the characteristics of simple preparation method, batch production, and good acid and alkali resistance. Therefore, the Mn 2+ :LiAlGeO4 long afterglow germanium silicate fluorescent glass ceramics have certain application potential in the fields of optical information storage, optical anti-counterfeiting, outdoor night display, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 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.

[0024] Figure 1 This is the XRD pattern of the product in Example 1.

[0025] Figure 2 This is the excitation spectrum of the product in Example 1.

[0026] Figure 3 This is the emission spectrum of the product of Example 1.

[0027] Figure 4 This is the afterglow spectrum of the product of Example 2 after ultraviolet light excitation.

[0028] Figure 5 This is the afterglow spectrum of the product of Example 2 after being excited by sunlight.

[0029] Figure 6 This is the afterglow decay curve of the product of Example 2 after being excited by sunlight. DETAILED DESCRIPTION

[0030] 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.

[0031] 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.

[0032] 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.

[0033] The terms “include,” “including,” “have,” “contain,” etc. used in the present invention are open-ended terms, meaning including but not limited to.

[0034] Unless otherwise specified, the "room temperature" in the present invention is 20-30°C.

[0035] The raw materials used in the following examples and comparative examples of the present invention are all commercially available products.

[0036] Example 1

[0037] Mn 2+ The raw materials of LiAlGeO4 long afterglow germanium silicate fluorescent glass ceramics are calculated by molar parts as follows:

[0038] 40 parts of GeO2, 5 parts of SiO2, 10 parts of Al2O3, 25 parts of ZnO, 10 parts of Li2CO3, 10 parts of K2CO3 and 0.1 parts of MnCO3.

[0039] Mn 2+ Preparation of LiAlGeO4 long afterglow germanosilicate fluorescent glass ceramics:

[0040] Use GeO2, SiO2, Al2O3, ZnO, Li2CO3, K2CO3, and MnCO3 powders with a purity of ≥99.99% as the initial raw materials, mix them in proportion, weigh 20g of the raw materials, put them into an agate mortar and grind them for 30 minutes to make them fully mixed. Pour the evenly mixed glass raw materials into an alumina crucible and cover it with a mullite lid, then place it in a 1350℃ silicon-molybdenum rod lifting furnace and melt it for 60 minutes, then quickly pour the molten glass liquid onto a stainless steel plate at room temperature and press it into solid glass with another stainless steel plate at room temperature, then quickly transfer the glass to a 450℃ muffle furnace for annealing for 2 hours, and after it cools naturally to room temperature, the initial glass can be obtained. Finally, the annealed initial glass is heated to 580℃ in a muffle furnace at a heating rate of 15℃ / min and kept warm for 2 hours to obtain Mn 2+ :LiAlGeO4 long afterglow germanosilicate fluorescent glass ceramics.

[0041] Figure 1 This is the XRD pattern of the product of Example 1. As can be seen from the figure, LiAlGeO4 nanocrystals are precipitated in the glass of this product after heat treatment.

[0042] Effect Verification 1

[0043] The product of Example 1 was tested for excitation spectrum (monitoring wavelength 540nm) and emission spectrum (excitation wavelength 340nm). The test results are as follows: Figure 2 and Figure 3 shown.

[0044] Figure 2 This is the excitation spectrum of the product in Example 1.

[0045] Figure 3 This is the emission spectrum of the product of Example 1.

[0046] Figure 2 and Figure 3 Shows the Mn content of this glass ceramic 2+ excitation and emission wavelengths; in this glass ceramic, Mn 2+ Located at the center of the tetrahedron, it has 4 coordinations, so Mn 2+In this system, the transition of 4T1→6A1 shows green luminescence (540 nm). The excitation spectrum shows that the optimal excitation wavelength is 340 nm, which belongs to Mn 2+ Typical excitation and emission wavelengths.

[0047] Example 2

[0048] Mn 2+ The raw materials of LiAlGeO4 long afterglow germanium silicate fluorescent glass ceramics are calculated by molar parts as follows:

[0049] 250 parts of GeO, 10 parts of SiO, 5 parts of Al2O3, 20 parts of ZnO, 15 parts of Li2CO3, 5 parts of K2CO3 and 0.1 parts of MnCO3.

[0050] Mn 2+ Preparation of LiAlGeO4 long afterglow germanosilicate fluorescent glass ceramics:

[0051] Use GeO2, SiO2, Al2O3, ZnO, Li2CO3, K2CO3, and MnCO3 powders with a purity of ≥99.99% as the initial raw materials, mix them in proportion, weigh 20g of the raw materials, put them into an agate mortar and grind them for 30 minutes to make them fully mixed. Pour the evenly mixed glass raw materials into an alumina crucible and cover it with a mullite lid, then place it in a 1400℃ silicon-molybdenum rod lifting furnace and melt it for 50 minutes, then quickly pour the molten glass liquid onto a stainless steel plate at room temperature and press it into solid glass with another stainless steel plate at room temperature, then quickly transfer the glass to a 450℃ muffle furnace for annealing for 2 hours, and after it cools naturally to room temperature, the initial glass can be obtained. Finally, the annealed initial glass is heated to 620℃ in a muffle furnace at a heating rate of 15℃ / min and kept warm for 3 hours to obtain Mn 2+ :LiAlGeO4 long afterglow germanosilicate fluorescent glass ceramics.

[0052] Effect Verification 2

[0053] The product of Example 2 was excited with 340nm ultraviolet light and sunlight for 5 minutes, and the afterglow spectrum was tested. Figure 4-5 shown.

[0054] The product of Example 2 was irradiated with sunlight for 20 minutes and the afterglow decay curve was tested. Figure 6 shown.

[0055] Figure 4 This is the afterglow spectrum of the product of Example 2 after ultraviolet light excitation.

[0056] Figure 5 This is the afterglow spectrum of the product of Example 2 after being excited by sunlight.

[0057] Figure 6 This is the afterglow decay curve of the product of Example 2 after being excited by sunlight.

[0058] like Figure 4 As shown in FIG, after 5 minutes of ultraviolet irradiation, the glass ceramics prepared in this embodiment detected strong green long afterglow luminescence. Figure 5 As shown in Figure 2, when the glass ceramic sample is exposed to sunlight for 5 minutes, a green long afterglow luminescence can also be detected. Figure 6 As shown, the glass ceramic was exposed to the solar system for 20 minutes. After 12 hours of afterglow decay, the afterglow luminescence intensity was still higher than the instrument background intensity, indicating that the glass ceramic can be effectively excited by sunlight to produce long afterglow luminescence, and is suitable for use in the field of night lighting display.

[0059] Example 3

[0060] Mn 2+ The raw materials of LiAlGeO4 long afterglow germanium silicate fluorescent glass ceramics are calculated by molar parts as follows:

[0061] GeO245 parts, SiO215 parts, Al2O37.5 parts, ZnO 22.5 parts, Li2CO35 parts, K2CO35 parts and MnCO30.1 parts.

[0062] Mn 2+ Preparation of LiAlGeO4 long afterglow germanosilicate fluorescent glass ceramics:

[0063] Use GeO2, SiO2, Al2O3, ZnO, Li2CO3, K2CO3, and MnCO3 powders with a purity of ≥99.99% as the initial raw materials, mix them in proportion, weigh 20g of the raw materials, put them into an agate mortar and grind them for 30 minutes to make them fully mixed. Pour the evenly mixed glass raw materials into an alumina crucible and cover it with a mullite lid, then place it in a 1450℃ silicon-molybdenum rod lifting furnace and melt it for 45 minutes, then quickly pour the molten glass liquid onto a stainless steel plate at room temperature and press it into solid glass with another stainless steel plate at room temperature, then quickly transfer the glass to a 500℃ muffle furnace for annealing for 2 hours, and after it cools naturally to room temperature, the initial glass can be obtained. Finally, the annealed initial glass is heated to 640℃ in a muffle furnace at a heating rate of 15℃ / min and kept warm for 3 hours to obtain Mn 2+ :LiAlGeO4 long afterglow germanosilicate fluorescent glass ceramics.

[0064] Example 4

[0065] Mn 2+ The raw materials of LiAlGeO4 long afterglow germanium silicate fluorescent glass ceramics are calculated by molar parts as follows:

[0066] 45 parts of GeO2, 5 parts of SiO2, 10 parts of Al2O3, 20 parts of ZnO, 15 parts of Li2CO3, 5 parts of K2CO3 and 0.1 parts of MnCO3.

[0067] Mn 2+ Preparation of LiAlGeO4 long afterglow germanosilicate fluorescent glass ceramics:

[0068] Use GeO2, SiO2, Al2O3, ZnO, Li2CO3, K2CO3, and MnCO3 powders with a purity of ≥99.99% as the initial raw materials, mix them in proportion, weigh 20g of the raw materials, put them into an agate mortar and grind them for 30 minutes to make them fully mixed. Pour the evenly mixed glass raw materials into an alumina crucible and cover it with a mullite lid, then place it in a 1500℃ silicon-molybdenum rod lifting furnace and melt it for 30 minutes, then quickly pour the molten glass liquid onto a stainless steel plate at room temperature and press it into solid glass with another stainless steel plate at room temperature, then quickly transfer the glass to a 500℃ muffle furnace for annealing for 2 hours, and after it cools naturally to room temperature, the initial glass can be obtained. Finally, the annealed initial glass is heated to 680℃ in a muffle furnace at a heating rate of 15℃ / min and kept warm for 4 hours to obtain Mn 2+ :LiAlGeO4 long afterglow germanosilicate fluorescent glass ceramics.

[0069] 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 Mn 2+ :LiAlGeO4 long afterglow germanium silicate fluorescent glass ceramics, characterized in that, The raw materials, in parts by mole, include: GeO2 30-50 parts, SiO2 5-15 parts, Al2O3 5-10 parts, ZnO 10-30 parts, Li2CO3 5-15 parts, K2CO3 5-10 parts and MnCO3 0.1 parts.

2. Mn according to claim 1 2+ : A method for preparing LiAlGeO4 long afterglow germanium silicate fluorescent glass ceramics, characterized in that: The following steps are involved: Mix the raw materials in proportion, smelt, shape, anneal, and heat treat to obtain the Mn 2+ :LiAlGeO4 long afterglow germanosilicate fluorescent glass ceramics.

3. The preparation method according to claim 2, characterized in that The mixing method is grinding in an agate mortar for 30 minutes.

4. The preparation method according to claim 2, characterized in that The smelting temperature is 1350-1500° C., and the smelting time is 30-60 minutes.

5. The preparation method according to claim 2, characterized in that The molding process comprises the following steps: The molten glass obtained after the melting operation is poured into a mold, and another mold is used to press-cast the molten glass into bulk glass.

6. The preparation method according to claim 2, characterized in that The annealing is performed at 450-500° C. for 2-4 hours.

7. The preparation method according to claim 2, characterized in that The heat treatment is performed by heating the temperature to 580-680° C. at a heating rate of 15° C. / min and keeping the temperature for 1-3 hours.

8. The Mn according to claim 1 2+ :Application of LiAlGeO4 long afterglow germanium silicate fluorescent glass ceramics in outdoor night display field.

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