A bimorph microcrystalline glass material, a preparation method and application thereof

Abstract

The application discloses a kind of double crystal phase microcrystalline glass materials and preparation method and application, belong to luminescent material technical field.The double crystal phase microcrystalline glass material includes Ca2Al2SiO7:Eu 2+ And CaAl2Si2O8:Eu 2+ Double crystal phase;The glass matrix of the double crystal phase microcrystalline glass material includes the following components: SiO2, Al2O3, CaO, Eu2O3.The double crystal phase in the double crystal phase microcrystalline glass material of the application is activated ion Eu 2+ Multiple doping sites are provided, so that the photoluminescence color and long afterglow light color can be realized from blue light to wide yellow light adjustable tuning;The thermal release peak of the double crystal phase microcrystalline glass material is wide and extends to high temperature 650K, and the defect energy level of the surface is very deep and the defect energy level energy storage performance is good.The double crystal phase microcrystalline glass material of the application provides technical support for high temperature scene warning sign and night vision lighting field.

Description

Technical Field

[0001] This invention belongs to the field of luminescent materials technology, specifically relating to a bicrystalline phase microcrystalline glass material, its preparation method, and its application. Background Technology

[0002] With the development of modern industrial production, long-afterglow luminescent materials with good thermal stability are often needed for warning signs in certain high-temperature environments. Long-afterglow luminescent materials are a type of photoluminescent material that emits visible light when photoexcited, while simultaneously storing some light energy in trap levels. After the excitation light stops, the stored energy or charge carriers are slowly released as photons, resulting in long-lasting light emission. The afterglow performance of long-afterglow luminescent materials is closely related to the depth of the defect levels. Generally, the shallower the defect level, the easier it is for charge carriers stored in the metastable defect levels to escape the traps under thermal disturbances at room temperature or even below, resulting in a shorter afterglow time, making it difficult to meet the application requirements of specific high-temperature environments. Conversely, if electrons are trapped in deep defect levels, they can only be slowly released under high-temperature conditions. Therefore, only long-afterglow luminescent materials with deep trap levels can meet the urgent needs of specific high-temperature applications.

[0003] Fluorescent microcrystalline glass is a type of composite material in which micro- and nanocrystalline phases are embedded in an amorphous glass matrix. It combines the advantages of high transparency, easy processing and molding, and low cost of glass, while also possessing the high luminescence efficiency of crystals. It has broad application prospects in solid-state lighting displays, fiber lasers, sensing, and radiation detection. Furthermore, fluorescent microcrystalline glass exhibits good physicochemical stability and can withstand high-temperature thermal shock. Therefore, it can be practically used in emergency displays, traffic signs, warning signs, and environmental beautification projects in high-temperature environments. CN 112537910A discloses a method for preparing long-afterglow luminescent Sr2MgSi2O7:Eu,Dy microcrystalline glass; in this technology, the defect energy level of the Sr2MgSi2O7:Eu,Dy microcrystalline phase is relatively shallow, and the pyrolysis peak T... m With a K value of 357K and a defect energy level depth of 0.7 eV, it is difficult to obtain potential applications in specific high-temperature scenarios. CN110156332A discloses a method for preparing long-afterglow luminescent SrAl2O4:Eu,Dy microcrystalline glass; similarly, the defect energy level depth of this material is also relatively shallow, only 0.47-0.49 eV, making it difficult to apply in high-temperature scenarios.

[0004] To address the problems encountered in the application of fluorescent glass-ceramics, the search for a fluorescent glass-ceramic with long afterglow luminescence characteristics at high temperatures and an afterglow duration of several hours is currently a key research focus in the field of luminescent materials. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a bicrystalline phase microcrystalline glass material, its preparation method and application; the bicrystalline phase microcrystalline glass material has long afterglow luminescence characteristics at high temperature, the emission wavelength is tunable, and the afterglow duration is as long as several hours.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides a bicrystalline phase microcrystalline glass material, the bicrystalline phase microcrystalline glass material comprising Ca2Al2SiO7:Eu 2+ and CaAl2Si2O8:Eu 2+ The glass matrix of the bicrystalline phase microcrystalline glass material comprises the following components: SiO2, Al2O3, CaO, and Eu2O3.

[0008] Currently, research on long-afterglow luminescent glass-ceramics largely focuses on the development of single-phase glass-ceramics. However, because a single phase is difficult to produce Eu... 2+ The activation ions provide abundant crystallographic sites, so the emission color of single-phase glass-ceramics is usually uniform and cannot be adjusted, which limits the wide application of the material.

[0009] To address the aforementioned challenges, the bicrystalline microcrystalline glass material of this invention simultaneously comprises Ca2Al2SiO7:Eu 2+ and CaAl2Si2O8:Eu 2+ Crystal phase, bicrystalline phase with activating ion Eu 2+ It provides multiple doping sites, so its photoluminescence color and long-afterglow emission color can be tunable over a wide range from blue to yellow.

[0010] As a preferred embodiment of the bicrystalline phase microcrystalline glass material of the present invention, the Ca2Al2SiO7:Eu 2+ and CaAl2Si2O8:Eu 2+ The twin phase is embedded in the glass matrix.

[0011] As a preferred embodiment of the bicrystalline phase microcrystalline glass material of the present invention, the glass matrix comprises the following components in molar percentage: SiO2 30%-50%, Al2O3 10%-30%, CaO 30%-50%, and Eu2O3 0.02%-0.2%.

[0012] As a more preferred embodiment of the bicrystalline phase microcrystalline glass material of the present invention, the glass matrix comprises the following components in molar percentage: SiO2 40%, Al2O3 20%, CaO 40%, Eu2O3 0.02%. Through extensive experiments, the inventors have discovered that, under preferred conditions, the above components can cause Ca2Al2SiO7:Eu to precipitate in situ under certain heat treatment conditions. 2+ and CaAl2Si2O8:Eu 2+ The bicrystalline phase grains improve the quantum efficiency of glass-ceramics and increase the afterglow time, thus greatly improving optical performance.

[0013] The present invention also provides a method for preparing the bicrystalline phase microcrystalline glass material, the method comprising the following steps:

[0014] S1. Grind SiO2, Al2O3, CaO and Eu2O3 to obtain a mixed powder;

[0015] S2. Place the mixed powder described in step S1 in a reducing atmosphere at a temperature of 1350-1550℃ and melt it for 1-6 hours. Pour it onto a preheated copper mold and cool it to form a precursor amorphous glass.

[0016] S3. The precursor amorphous glass described in step S2 is heat-treated in a reducing atmosphere to obtain the bicrystalline phase microcrystalline glass material.

[0017] In a preferred embodiment of the preparation method of the bicrystalline phase microcrystalline glass material of the present invention, the immersion time in step S1 is 20-30 min.

[0018] In a preferred embodiment of the preparation method of the bicrystalline phase microcrystalline glass material of the present invention, the reducing atmosphere in steps S2 and S3 is provided by H, CO or carbon powder.

[0019] In a preferred embodiment of the preparation method of the bicrystalline phase microcrystalline glass material of the present invention, in step S2, the mixed powder of step S1 is placed in a reducing atmosphere at a temperature of 1500°C for 4 hours to melt.

[0020] In a preferred embodiment of the preparation method of the bicrystalline phase microcrystalline glass material of the present invention, the temperature of the preheated copper mold in step S2 is 400-450℃.

[0021] In a preferred embodiment of the preparation method of the bicrystalline phase microcrystalline glass material of the present invention, in step S3, the heat treatment temperature is 1000-1200℃ and the heat treatment time is 2-8h. The inventors have found through a large number of experiments that in the present invention, if the heat treatment temperature is lower than 1000℃, the glass will not be able to precipitate the crystalline phase. If the heat treatment temperature is too high, the glass will soften and the precipitated crystalline phase may remelt.

[0022] In a more preferred embodiment of the preparation method of the bicrystalline phase microcrystalline glass material of the present invention, the heat treatment temperature is 1050-1200℃ and the heat treatment time is 2-6h.

[0023] The present invention also provides the application of the aforementioned bicrystalline microcrystalline glass material in warning signs in high-temperature scenarios.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] The bicrystalline microcrystalline glass material of this invention simultaneously incorporates Ca2Al2SiO7:Eu 2+ and CaAl2Si2O8:Eu 2+ Crystal phase, bicrystalline phase with activating ion Eu 2+ The invention provides multiple doped lattice sites, thus enabling wide-range tunability of both photoluminescence and long-afterglow emission colors, ranging from blue to yellow. The bicrystalline microcrystalline glass material of this invention exhibits broad pyroelectric peaks that extend to a high temperature of 650K, and possesses very deep defect energy levels with excellent energy storage performance. This bicrystalline microcrystalline glass material provides technical support for warning signs and night vision lighting in high-temperature environments. Attached Figure Description

[0026] Figure 1 These are the XRD patterns of the microcrystalline glass materials or non-glass materials described in Examples 1-3 and Comparative Examples 1-2 of this invention;

[0027] Figure 2 This is the normalized excitation and emission spectrum of a bicrystalline phase microcrystalline glass material obtained by heat treatment at 1050°C for 2 hours according to one embodiment of the present invention.

[0028] Figure 3 This is the normalized excitation and emission spectrum of a bicrystalline phase microcrystalline glass material obtained by heat treatment at 1200℃ for 2 hours according to one embodiment of the present invention;

[0029] Figure 4 This is the normalized excitation and emission spectrum of a bicrystalline phase microcrystalline glass material obtained by heat treatment at 1100℃ for 2 hours according to one embodiment of the present invention.

[0030] Figure 5This is a perspective view of the bicrystalline phase microcrystalline glass material according to one embodiment of the present invention;

[0031] Figure 6 This is an X-ray fluorescence spectrum of the bicrystalline phase microcrystalline glass material according to one embodiment of the present invention;

[0032] Figure 7 This is a temperature-varying spectrum of the bicrystalline phase microcrystalline glass material from 300K to 500K according to one embodiment of the present invention;

[0033] Figure 8 This is the afterglow decay curve of the bicrystalline phase microcrystalline glass material described in one embodiment of the present invention;

[0034] Figure 9 This is a pyroelectric spectrum of the bicrystalline phase microcrystalline glass material according to one embodiment of the present invention;

[0035] Figure 10 This is a high-temperature emission spectrum of the bicrystalline phase microcrystalline glass material according to one embodiment of the present invention;

[0036] Figure 11 This is a normalized excitation and emission spectrum of the amorphous glass according to one embodiment of the present invention. Detailed Implementation

[0037] To better illustrate the purpose, technical solution, and advantages of this invention, the invention will be further described below with reference to specific embodiments and comparative examples. The purpose of this description is to provide a detailed understanding of the invention, not to limit its scope. All other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this invention. Unless otherwise specified, the experimental reagents and instruments involved in the implementation of this invention are commonly used reagents and instruments.

[0038] Example 1

[0039] The preparation method of the bicrystalline phase microcrystalline glass material described in this embodiment is as follows:

[0040] S1. Weigh each component according to the molar content of SiO2 40%, Al2O3 20%, CaO 40%, and Eu2O3 0.02%. Mix and grind SiO2, Al2O3, CaO and Eu2O3 for 30 minutes to obtain mixed powder, and put it into a corundum crucible.

[0041] S2. Place the crucible containing the mixed powder from step S1 into a large covered crucible filled with activated carbon, and heat it in a box furnace at 1500℃ for 4 hours to melt it. After melting at high temperature, immediately pour it into a copper mold preheated at 400℃ and cool it rapidly to obtain the precursor amorphous glass.

[0042] S3. The precursor amorphous glass described in step S2 is heat-treated in a reducing atmosphere at a temperature of 1050°C for 2 hours to obtain the bicrystalline phase microcrystalline glass material.

[0043] The XRD pattern of the bicrystalline microcrystalline glass material prepared in this embodiment is as follows: Figure 1 As shown, Figure 1 The results show that Ca2Al2SiO7:Eu precipitates in the bicrystalline phase microcrystalline glass material described in Example 1. 2+ and CaAl2Si2O8:Eu 2+ The bicrystalline phase, the microcrystalline glass material described in Example 1, exhibited bright blue-green luminescence. Its excitation and emission spectra at room temperature were measured using an Edinburgh FS980 fluorescence spectrometer, and the results are as follows: Figure 2 As shown; the emission spectrum shows that Eu 2+ 4f 6 5d 1 -4f 7 The transition is a typical broad-peak emission, with a center wavelength of 467nm and a full width at half maximum (FWHM) of 146nm.

[0044] Example 2

[0045] The preparation method of the bicrystalline phase microcrystalline glass material described in this embodiment is as follows:

[0046] S1. Weigh each component according to the molar content of SiO2 40%, Al2O3 20%, CaO 40%, and Eu2O3 0.2%. Mix and grind SiO2, Al2O3, CaO and Eu2O3 for 30 minutes to obtain mixed powder, and put it into a corundum crucible.

[0047] S2. Place the crucible containing the mixed powder from step S1 into a large covered crucible filled with activated carbon, and heat it in a box furnace at 1500℃ for 4 hours to melt it. After melting at high temperature, immediately pour it into a copper mold preheated at 400℃ and cool it rapidly to obtain the precursor amorphous glass.

[0048] S3. The precursor amorphous glass described in step S2 is heat-treated in a reducing atmosphere at a temperature of 1200°C for 2 hours to obtain the bicrystalline phase microcrystalline glass material.

[0049] The XRD pattern of the bicrystalline microcrystalline glass material prepared in this embodiment is as follows: Figure 1 As shown, Figure 1 As shown, the bicrystalline phase microcrystalline glass material described in Example 2 precipitates Ca2Al2SiO7:Eu 2+ and CaAl2Si2O8:Eu 2+The bicrystalline phase, the microcrystalline glass material described in Example 1, exhibited bright blue-green luminescence. Its excitation and emission spectra at room temperature were measured using an Edinburgh FS980 fluorescence spectrometer, and the results are as follows: Figure 3 As shown, the emission spectrum shows double-peak emission, with emission peaks at 434 nm in the blue region and 528 nm in the green region.

[0050] Example 3

[0051] The preparation method of the bicrystalline phase microcrystalline glass material described in this embodiment is as follows:

[0052] S1. Weigh each component according to the molar content of SiO2 40%, Al2O3 20%, CaO 40%, and Eu2O3 0.02%. Mix and grind SiO2, Al2O3, CaO and Eu2O3 for 30 minutes to obtain mixed powder, and put it into a corundum crucible.

[0053] S2. Place the crucible containing the mixed powder from step S1 into a large covered crucible filled with activated carbon, and heat it in a box furnace at 1500℃ for 2 hours to melt it. After melting at high temperature, immediately pour it into a copper mold preheated at 400℃ and cool it rapidly to obtain the precursor amorphous glass.

[0054] S3. The precursor amorphous glass described in step S2 is heat-treated in a reducing atmosphere at a temperature of 1200°C for 2 hours to obtain the bicrystalline phase microcrystalline glass material.

[0055] The XRD pattern of the bicrystalline microcrystalline glass material prepared in this embodiment is as follows: Figure 1 As shown, Figure 1 As shown, the bicrystalline phase microcrystalline glass material described in Example 3 precipitates Ca2Al2SiO7:Eu 2+ and CaAl2Si2O8:Eu 2+ Bicrystalline phase; The microcrystalline glass material described in Example 3 exhibited bright blue-green luminescence. Its excitation and emission spectra at room temperature were measured using an Edinburgh FS980 fluorescence spectrometer, and the results are as follows: Figure 4 As shown, the emission spectrum shows a double-peak emission with a peak at 423 nm and a half-peak width of 78 nm.

[0056] The 1mm thick bicrystalline microcrystalline glass prepared in this embodiment maintains a certain degree of transparency, allowing the numbers behind it to be seen, such as... Figure 5 As shown.

[0057] Figure 6 The results showed that X-ray fluorescence spectroscopy revealed that the microcrystalline glass material is composed of Ca, Al, and Si.

[0058] The temperature-varying spectrum of the bicrystalline phase microcrystalline glass material from 300K to 500K was measured, and the results are as follows: Figure 7 As shown, the bicrystalline microcrystalline glass material still exhibits a certain luminescence intensity at 500K.

[0059] The afterglow duration of the bicrystalline phase microcrystalline glass material was measured at room temperature, and the results are as follows: Figure 8 As shown, the afterglow duration of the microcrystalline glass material after charging is still an order of magnitude higher than the background intensity after 1 hour.

[0060] The bicrystalline phase microcrystalline glass material was subjected to THL pyroelectric spectroscopy. Figure 9 The results show that the pyrolysis peak of the microcrystalline glass material is broad and extends to a high temperature of 650K, indicating that the microcrystalline glass material has a very deep defect energy level and good energy storage performance of the defect energy level.

[0061] The emission spectrum of the bicrystalline phase glass-ceramic material was tested at 437 K, and the results are as follows: Figure 10 As shown, due to the deep defect energy levels of the bicrystalline microcrystalline glass, electrons stored in the deep traps are released at high temperatures and then released as photons as they return from the conduction band to the valence band. Therefore, it has good long afterglow emission at 473k.

[0062] Example 4

[0063] The difference between the preparation method of the bicrystalline phase microcrystalline glass material described in this embodiment and that in Example 1 is only that: in step S1, each component is weighed according to the molar content of SiO2 30%, Al2O3 10%, CaO 50%, and Eu2O3 0.2%; the rest are the same as in Example 1.

[0064] The bicrystalline phase microcrystalline glass material exhibits bright blue-green luminescence and long afterglow luminescence characteristics at high temperatures.

[0065] Example 5

[0066] The difference between the preparation method of the bicrystalline phase microcrystalline glass material described in this embodiment and that in Example 1 is only that: in step S1, each component is weighed according to the molar content of SiO2 50%, Al2O3 30%, CaO 30%, and Eu2O3 0.02%; the rest are the same as in Example 1.

[0067] The bicrystalline microcrystalline glass material exhibits bright blue-green luminescence, while the sample also has a certain degree of transparency and can exhibit long afterglow luminescence well at high temperatures.

[0068] Comparative Example 1

[0069] The preparation method of the microcrystalline glass material described in this comparative example is as follows:

[0070] S1. Weigh each component according to the molar content of SiO2 40%, Al2O3 20%, CaO 40%, and Eu2O3 0.02%. Mix and grind SiO2, Al2O3, CaO and Eu2O3 for 30 minutes to obtain mixed powder, and put it into a corundum crucible.

[0071] S2. Place the crucible containing the mixed powder from step S1 into a large covered crucible filled with activated carbon, and heat it in a box furnace at 1500℃ for 4 hours to melt it. After melting at high temperature, immediately pour it into a copper mold preheated at 400℃ and cool it rapidly to obtain the precursor amorphous glass.

[0072] S3. The precursor amorphous glass described in step S2 is heat-treated in a reducing atmosphere at a temperature of 900°C for 8 hours to obtain the amorphous glass material.

[0073] The XRD pattern of the amorphous glass material prepared in this comparative example is as follows: Figure 1 As shown, Figure 1 As shown, compared with Example 1, the amorphous glass material showed no crystalline phase precipitation.

[0074] Comparative Example 2

[0075] The preparation method of the microcrystalline glass material described in this comparative example is as follows:

[0076] S1. Weigh each component according to the molar content of SiO2 40%, Al2O3 20%, CaO 40%, and Eu2O3 0.02%. Mix and grind SiO2, Al2O3, CaO and Eu2O3 for 30 minutes to obtain mixed powder, and put it into a corundum crucible.

[0077] S2. Place the crucible containing the mixed powder from step S1 into a large covered crucible filled with activated carbon, and heat it in a box furnace at 1500℃ for 4 hours to melt it. After melting at high temperature, immediately pour it into a copper mold preheated at 400℃ and cool it rapidly to obtain the precursor amorphous glass.

[0078] The XRD pattern of the amorphous glass material prepared in this comparative example is as follows: Figure 1 As shown, Figure 1 As shown, compared with Example 1, the amorphous glass material showed no crystalline phase precipitation. Figure 11 The results show that its excitation peak is at 365nm and its emission peak is at 478nm.

[0079] Comparative Example 3

[0080] The preparation method of the microcrystalline glass material described in this comparative example is as follows:

[0081] S1. Weigh each component according to the molar content of SiO2 40%, Al2O3 20%, CaO 40%, and Eu2O3 0.02%. Mix and grind SiO2, Al2O3, CaO and Eu2O3 for 30 minutes to obtain mixed powder, and put it into a corundum crucible.

[0082] S2. Place the crucible containing the mixed powder from step S1 into a large covered crucible filled with activated carbon, and heat it in a box furnace at 1500℃ for 4 hours to melt it. After melting at high temperature, immediately pour it into a copper mold preheated at 400℃ and cool it rapidly to obtain the precursor amorphous glass.

[0083] S3. The precursor amorphous glass described in step S2 is heat-treated in a reducing atmosphere at a temperature of 1300°C for 8 hours. The resulting glass softens and cannot be used to obtain microcrystalline glass.

[0084] In summary, the bicrystalline phase microcrystalline glass material prepared in the embodiments of the present invention has high crystallinity and a certain degree of transparency; when the heat treatment temperature is within the range of the present invention, different Eu values... 2+ Microcrystalline glass materials prepared at certain doping concentrations can emit broadband spectra in the 400-700 nm wavelength range under ultraviolet light excitation, and the doping concentration increases with increasing Eu concentration. 2+ As the doping concentration increases, the excitation peak shifts from blue light to green light; after the illumination stops, the microcrystalline glass material exhibits long afterglow luminescence characteristics, with an afterglow duration of up to several hours.

[0085] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present invention and not to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A bicrystalline phase microcrystalline glass material, characterized in that, The bicrystalline glass-ceramic material includes Ca2Al2SiO7:Eu 2+ and CaAl2Si2O8:Eu 2+ The bicrystalline phase; the glass matrix of the bicrystalline phase microcrystalline glass material comprises the following molar percentage components: SiO2 30%-50%, Al2O3 10%-30%, CaO 30%-50%, and externally doped Eu2O3 0.02%-0.2%; the preparation method of the bicrystalline phase microcrystalline glass material includes the following steps: S1. Grind SiO2, Al2O3, CaO and Eu2O3 to obtain a mixed powder; S2. Place the mixed powder described in step S1 in a reducing atmosphere at a temperature of 1350-1550℃ and melt it for 1-6 hours. Pour it onto a preheated copper mold and cool it to form a precursor amorphous glass. S3. Heat-treat the precursor amorphous glass described in step S2 in a reducing atmosphere to obtain the bicrystalline phase microcrystalline glass material. In step S3, the heat treatment temperature is 1000-1200℃ and the heat treatment time is 2-8h.

2. The bicrystalline phase microcrystalline glass material as described in claim 1, characterized in that, The Ca2Al2SiO7:Eu 2+ and CaAl2Si2O8:Eu 2+ The twin phase is embedded in the glass matrix.

3. The bicrystalline phase microcrystalline glass material as described in claim 1, characterized in that, The glass matrix comprises the following components in molar percentage: 40% SiO2, 20% Al2O3, 40% CaO, and 0.02% Eu2O3.

4. The bicrystalline phase microcrystalline glass material as described in claim 1, characterized in that, In step S3, the heat treatment temperature is 1050-1200℃ and the heat treatment time is 2-6h.

5. The application of the bicrystalline microcrystalline glass material according to any one of claims 1-4 in warning signs in high-temperature environments.

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