A method for preparing a photothermal dynamically tunable color long afterglow transparent glass-ceramic and its application

Abstract

This invention discloses a method for preparing a photothermal dynamically tunable color-changing long-afterglow transparent glass-ceramic and its application. The raw materials are weighed and mixed according to the molar ratio of 39.5 parts ZnO, 30 parts SiO2, 10 parts Al2O3, 10 parts H3BO3, 6-10 parts K2CO3, 1-4 parts Li2CO3, and 0.5 parts MnCO3, then ground uniformly. The mixture is then fully melted in a high-temperature furnace under a reducing atmosphere, cooled and annealed to obtain the original glass. Further heat treatment is performed under a reducing atmosphere, followed by polishing to obtain a dynamically tunable color-changing long-afterglow transparent glass-ceramic. The material of this invention exhibits dynamic afterglow color control characteristics dependent on the excitation wavelength or charging temperature. This breaks through the application limitation of traditional afterglow materials that can only emit light statically. For the first time, multi-mode dynamically tunable color-changing afterglow luminescence is achieved in a single glass body. Furthermore, the good thermal stability and high hardness value confirm that the material has good application tolerance under extreme working environments.

Description

Technical Field

[0001] This invention relates to the preparation and application of a long-afterglow luminescent material, specifically to the preparation of a light / heat controllable dynamic multicolor long-afterglow luminescent transparent glass ceramic and its application in information storage and display. Background Technology

[0002] Long-afterglow luminescent materials can maintain continuous radiation for a long time after the removal of external excitation. This unique optical energy storage characteristic makes them promising for applications in multi-color displays, high-density information storage, and dynamic optical encryption. However, existing long-afterglow luminescent materials (including inorganic, organic, or hybrid systems) generally suffer from inherent limitations such as a single emission color and static untuning. Their afterglow output lacks the ability to evolve in the spatiotemporal dimensions, making it difficult to meet the urgent needs of next-generation multifunctional optoelectronic devices for dynamically programmable optical information. At the same time, environmental stability (such as abrasion resistance and resistance to damp heat aging) and ease of application are also significant challenges for these materials in practical applications.

[0003] In comparison, transparent glass / ceramics exhibit irreplaceable comprehensive advantages in physicochemical stability (including high hardness, corrosion resistance, and thermal stability). On the one hand, glass materials can achieve controllable precipitation of nanocrystals within the glass matrix through phase separation strategies, designing multi-coordination environments for activator ions. On the other hand, through ion doping, component regulation, and thermal process adjustments, the crystal field environment and defect state environment of the activator ions can be further customized, thereby constructing multicolor afterglow emission centers with different decay dynamics within a single glass-ceramic system. This is expected to break through the inherent paradigm of static, monochromatic emission in traditional long-afterglow materials, realizing the dynamic evolution of afterglow color in a monolithic, transparent solid medium, providing a revolutionary solution for the development of high-dimensional information storage materials. Furthermore, its inherent excellent optical transparency directly empowers the construction of true three-dimensional information storage platforms. Summary of the Invention

[0004] To address the technical problem that existing single-system long-afterglow luminescent materials can only achieve static, monochromatic emission, thus severely limiting their application in multidimensional optical information storage, this paper provides a light / thermal dynamically tunable color long-afterglow luminescent transparent glass-ceramic, its preparation method, and its applications.

[0005] The afterglow emission color of the fabricated glass-ceramic can be easily tuned by changing the excitation wavelength and excitation temperature. Furthermore, dynamic multicolor afterglow emission can be achieved in a single glass-ceramic body by changing the local temperature field and local excitation wavelength, giving it great application potential in the field of optical information storage.

[0006] The technical solution of the present invention: I. A photothermal dynamically adjustable color-changing long-afterglow luminescent transparent glass-ceramic: The original glass of the transparent glass ceramic is composed of the following molar fractions: 39.5 parts ZnO, 30 parts SiO2, 10 parts Al2O3, 10 parts H3BO3, 6-10 parts K2CO3, 1-4 parts Li2CO3 and 0.5 parts MnCO3.

[0007] The main crystalline phase of the transparent glass-ceramic is Zn1.7SiO4:Li. Mn 2+ The two emission peaks are located in the Zn1.7SiO4:Li nanocrystalline phase and glass phase, respectively, with the two emission peaks located in the 520-540 nm and 600-650 nm wavelength bands, respectively.

[0008] The excitation wavelength range of the transparent glass ceramic is 254 nm-380 nm, and the excitation / charging temperature range is 20℃-250℃.

[0009] The transparent glass ceramic is excited by laser light of the excitation wavelength at the ambient temperature of the excitation temperature to produce long afterglow emission, and the afterglow color can be changed with the excitation temperature or the excitation wavelength.

[0010] II. A method for preparing a photothermal dynamically tunable color-changing long-afterglow luminescent transparent glass-ceramic: The method includes the following steps: S1. Weigh out the glass raw materials according to the molar ratio and composition of 39.5 parts ZnO, 30 parts SiO2, 10 parts Al2O3, 10 parts H3BO3, 6-10 parts K2CO3, 1-4 parts Li2CO3 and 0.5 parts MnCO3, mix them and grind them evenly to obtain the mixed raw materials; S2. The mixed raw materials are fully melted in a high-temperature furnace under a reducing atmosphere, cooled and shaped, and then annealed to obtain the original glass. S3. The original glass is heat-treated in a reducing atmosphere and polished to obtain a dynamically tunable color long afterglow luminescent glass-ceramic.

[0011] In step S2), the melting temperature is 1430-1480 ℃, the time is 40 min, the reducing atmosphere is provided by activated carbon particles, the cooling and molding temperature is 300-350 ℃, and the annealing temperature is 500 ℃.

[0012] In step S3), the heat treatment temperature is 620-700 ℃, the heating rate is 7 ℃ / min, and the holding time is 120-180min.

[0013] III. A method for photothermal dynamically tunable color-changing long-afterglow luminescence of transparent glass-ceramics: The method is controlled as follows: Within the excitation temperature range of 20 ℃-80 ℃, changing the external excitation wavelength from 254 nm to 365 nm causes a reversible change in the afterglow color from green to orange-red due to the bimodal emission intensity change of the transparent glass ceramic. Within the wavelength range of 350 nm to 380 nm, changing the excitation temperature from 20 ℃ to 250 ℃ causes a reversible change in the afterglow color from orange-red to green due to the bimodal emission intensity change of the transparent glass ceramic.

[0014] The application of the aforementioned photothermal dynamically adjustable color long afterglow luminescent transparent glass ceramic in information storage and display.

[0015] The long afterglow described in this invention refers to afterglow emission that lasts for at least 30 minutes after the laser excitation is removed; specific experimental tests have shown that afterglow emission lasts for 2 hours.

[0016] This invention first precisely controls the Li2CO3 doping concentration and the phase separation process during heat treatment to drive the in-situ controllable precipitation of non-stoichiometric Zn from the glass matrix. 1.7 SiO4:Li nanocrystals are formed, creating a dual-phase composite structure where the glassy and crystalline phases coexist. Secondly, by controlling the subsequent heat treatment process, the activation of Mn ions is guided... 2+ Selective distribution occurs between the glass and crystalline phases, while the concentration of deep traps within the crystalline phase is selectively enhanced. Ultimately, based on this differentiated two-phase structure and defect modulation, the material can achieve dynamic, reversibly modulated long-afterglow luminescence depending on the excitation wavelength or charging temperature.

[0017] The core of this invention lies in: using Li + A doping-synergistic thermal treatment phase separation strategy enables the controllable in-situ precipitation of non-stoichiometric Zn1.7SiO4:Li nanocrystals in glass, with Mn acting as an activator ion. 2+ By providing differentiated dual-phase (glassy / crystalline) coordination environments and localized defect states, different afterglow decay dynamics can be constructed at the dual emission centers. The resulting material exhibits dynamic afterglow color modulation characteristics dependent on excitation wavelength or charging temperature. This makes it of significant application potential in high-dimensional optical information fields such as multi-dimensional information storage and dynamic anti-counterfeiting. Meanwhile, the material's high mechanical hardness and thermal stability indicate its resilience in extreme environments.

[0018] The beneficial effects of this invention are as follows: (1) The light / heat dynamically tunable color long afterglow luminescent transparent glass-ceramic prepared by this invention has sensitive wavelength / temperature response characteristics: when switching the excitation wavelength or changing the charging temperature, a dynamic and reversible afterglow color change from green to orange can be achieved. Based on this characteristic, different colors of afterglow information can be written into different regions of the same glass-ceramic material simply by adjusting the excitation wavelength or the local temperature field. This method breaks through the bottleneck of traditional afterglow materials being limited by chemical composition and spatial distribution when controlling the luminescence color, and provides a highly convenient material basis for applications such as multicolor dynamic display, high-dimensional information storage, and spatial programmable encryption.

[0019] (2) The glass-ceramic prepared by this invention has a hardness of up to 9.3-10.7 GPa, which is superior to the hardness of most transparent glass-ceramics and has good thermal stability. Therefore, this material can maintain structural integrity and performance stability under extreme environments such as high temperature and high mechanical stress, thus expanding its application range in practical working conditions.

[0020] (3) The transparent glass ceramic prepared by the present invention can be combined with femtosecond laser direct writing technology to directly realize the drawing of afterglow patterns and information encoding in three-dimensional space inside the material, breaking through the technical bottleneck of traditional luminescent materials being limited to surface or two-dimensional patterning, and providing key technical support for multi-dimensional light storage and dynamic three-dimensional display. Attached Figure Description

[0021] Figure 1 The XRD diffraction pattern and optical photograph of the sample in Example 1 are shown.

[0022] Figure 2 The images show the afterglow emission spectra of the sample from Example 1 after excitation at 365 nm and 254 nm.

[0023] Figure 3 The afterglow spectral chromaticity diagram of the glass-ceramic sample in Example 1 is a temperature-dependent result of charging.

[0024] Figure 4 The changes in fluorescence intensity and afterglow intensity of the glass-ceramic sample under varying temperature conditions in Example 1 are shown.

[0025] Figure 5 Thermal stability (cold and hot cycling) test of fluorescence / afterglow intensity of glass-ceramic sample in Example 1.

[0026] Figure 6 The value represents the hardness of the glass / glass-ceramic sample prepared in Example 1.

[0027] Figure 7 This is a physical image of a photomask used in Example 1 for multicolor afterglow information storage / display (by changing the local charging temperature field).

[0028] Figure 8 This is a physical image of a photomask used in Example 1 for multicolor afterglow information storage / display (utilizing local excitation wavelength changes).

[0029] Figure 9 The glass-ceramic prepared in Example 1 is used in a three-dimensional afterglow information storage image.

[0030] Figure 10 The image shows the afterglow emission spectrum of the glass-ceramic prepared in Comparative Example 1 under 254 nm excitation.

[0031] Figure description: GCXXX, glass-ceramics, XXX represents the heat treatment temperature for glass-ceramic applications. BG, untreated sample.

[0032] Table 1 compares the dynamic tunable afterglow performance of different materials.

[0033] Table 2 shows the composition systems and hardness values ​​(GPa) of common transparent glass-ceramic systems. Detailed Implementation

[0034] The present invention will be further described below with reference to embodiments, but these embodiments are not intended to limit the scope of the invention.

[0035] The embodiments of the present invention are as follows: Example 1 A method for preparing a light / heat dynamically tunable color long afterglow luminescent transparent glass-ceramic is as follows: Weigh out 12g of the corresponding chemical raw materials according to the following composition and molar percentages: 39.5% ZnO, 30% SiO2, 10% Al2O3, 10% H3BO3, 7% K2CO3, 3% Li2CO3, and 0.5% MnCO3. Grind the mixture in an agate mortar for 15 minutes to ensure thorough mixing. Place the mixture in an alumina crucible and transfer it to a large crucible (300ml) containing activated carbon particles (1-2mm diameter) in a high-temperature furnace at 1450℃. Cover and melt for 40 minutes. Pour the molten glass onto a brass plate at 300℃ to cool and solidify. Then, transfer the solidified glass to a muffle furnace at 500℃ for annealing for 2 hours to eliminate internal stress and obtain the original glass.

[0036] The original glass was heated to a temperature range of 620 ℃-700 ℃ at a heating rate of 7 ℃ / min and held at that temperature for 2 hours to carry out a crystallization reaction, ultimately yielding a Zn-containing glass. 1.7 Transparent glass-ceramic sample of SiO4 nanocrystals ( Figure 1 ).

[0037] The afterglow color of this material exhibits a significant excitation wavelength dependence: at room temperature charging temperature, when the excitation wavelength changes from 365 nm to 254 nm, the intensity of the bimodal peaks in its emission spectrum changes dynamically, with a significant enhancement in the green band, leading to a macroscopic afterglow color shift from orange to green. Figure 2 ).

[0038] Meanwhile, under the condition of fixed excitation at 365 nm, the afterglow color also exhibits an excitation temperature dependence: taking sample GC700 as an example, as the excitation / charge temperature increases from 298 K to 473 K, the afterglow color also changes from orange to green, and its CIE color coordinates correspondingly change from (0.483, 0.489) to (0.410, 0.551). Figure 3 ).

[0039] The afterglow emission intensity of the test material was measured at different temperature points. The afterglow emission intensity measured after excitation at 125 ℃ was still higher than that measured after excitation at room temperature. Figure 4 ).

[0040] Meanwhile, after multiple thermal cycling tests under 254 nm excitation, the material's fluorescence intensity and afterglow intensity remained stable. Figure 5 The above results demonstrate the excellent high-temperature luminescence stability of this glass-ceramic.

[0041] Its dual-mode (excitation wavelength, temperature) afterglow color modulation capability and high temperature stability have significant advantages over previously reported dynamic multicolor long afterglow materials (Table 1).

[0042] Table 1: Comparison of Dynamically Tunable Afterglow Performance in Different Materials In addition, compared with previously reported transparent glass-ceramics, this glass / glass-ceramic exhibits a superior hardness value, reaching up to 10.7 GPa. Figure 6 (Table 2).

[0043] Table 2: Common Transparent Glass-Ceramic Composition Systems and Hardness Values ​​(GPa) Example 2 A method for preparing a light / heat dynamically tunable color long afterglow luminescent transparent glass-ceramic is as follows: Weigh out 12 g of the corresponding chemical raw materials according to the following composition and molar percentages: 39.5% ZnO, 30% SiO2, 10% Al2O3, 10% H3BO3, 6% K2CO3, 4% Li2CO3, and 0.5% MnCO3. Grind the mixture in an agate mortar for 15 min to ensure thorough mixing. Place the mixture in an alumina crucible and transfer it to a large crucible (300 ml) containing activated carbon particles (1-2 mm diameter) in a high-temperature furnace at 1430 °C. Cover and melt for 40 min. Pour the molten glass onto a brass plate at 300 °C to cool and solidify. Then, transfer the solidified glass to a muffle furnace at 500 °C for annealing for 2 hours to eliminate internal stress and obtain the original glass.

[0044] The original glass was heated to 600℃-680℃ at a heating rate of 7℃ / min and held at that temperature for two hours to carry out a crystallization reaction, ultimately yielding a Mn-containing glass. 2+ Activated Zn 1.7 SiO4:Li nanocrystals are light / thermal dynamically tunable, color-changing, long-afterglow luminescent transparent glass-ceramics.

[0045] Application testing: 1) Application of local temperature field changes in multidimensional information storage / display: The long-afterglow luminescent glass-ceramic surface prepared in Example 1 was photomasked, and a differential temperature field (298 K / 423 K) was provided in different regions of the glass using a soldering iron, followed by pre-charging at 365 nm. After the UV lamp was turned off, different regions of the glass exhibited different afterglow colors. Specifically, the sample charged at 423 K showed green afterglow emission, while the region charged at room temperature showed orange afterglow emission, thus achieving the effect of multi-dimensional information storage / encryption. Figure 7 ).

[0046] 2) Application of excitation wavelength variation in multidimensional information storage / display: The long-afterglow luminescent glass-ceramic surface prepared in Example 1 was subjected to photomask treatment, and differentiated excitation wavelengths (365 nm / 254 nm) or their combinations were provided in different regions of the glass for pre-charging of the sample. After the ultraviolet lamp was turned off, different regions of the glass exhibited different afterglow colors. Specifically, the glass-ceramic region excited by 365 nm for 2 s exhibited orange afterglow emission, the glass-ceramic region excited by 254 nm for 2 s exhibited green emission, and the glass-ceramic region excited by 254 nm and then by 365 nm ultraviolet light for 1 s successively exhibited yellow afterglow emission, thus achieving the effect of multi-dimensional information storage / encryption. Figure 8 ).

[0047] 3) Applications in three-dimensional spatial information storage: By focusing a femtosecond laser (365 nm, 2 W, 11 kHz) beam into the glass and controlling the displacement coordinates (X, Y, Z) of the laser focus in three-dimensional space to change the excitation path, it is possible to write afterglow information into the glass in three-dimensional space. Figure 9 ).

[0048] Comparative Example 1: According to the following composition and molar percentages: 39.5% ZnO, 30% SiO2, 10% Al2O3, 10% H3BO3, 10% K2CO3, 0% Li2CO3, and 0.5% MnCO3, 12 g of the corresponding chemical raw materials were weighed and ground in an agate mortar for 15 min to ensure thorough mixing. The mixture was placed in an alumina crucible and transferred to a large crucible (300 ml) containing activated carbon particles (1-2 mm diameter) in a high-temperature furnace at 1430 °C, and then covered and melted for 40 min. The molten glass was poured onto a brass plate at 300 °C to cool and solidify. The solidified glass was then transferred to a muffle furnace at 500 °C for annealing for 2 hours to eliminate internal stress and obtain the original glass. Transparent afterglow glass-ceramic containing the β-Zn2SiO4 crystalline phase was successfully prepared by crystallizing the original glass at a rate of 7 °C / min to 700 °C and holding for 2 hours. Under 254 nm excitation, the emission spectrum of this material mainly consists of two bands: 582 nm and 647 nm, corresponding to Mn in the β-Zn2SiO4 crystal phase, respectively. 2+ The luminescence of Mn in the glass phase 2+ The emission is luminescent. However, due to the weak intensity of the emission peak at 582 nm and the small wavelength difference between the two peaks, its spectrum is difficult to visually exhibit a significant change in intensity distribution, thus failing to achieve afterglow emission with dynamic tunability. Figure 10 ).

[0049] As can be seen from this implementation, the material of the present invention exhibits the characteristic of dynamic adjustment of afterglow color depending on the excitation wavelength or charging temperature. This breaks the application limitation of traditional afterglow materials that can only emit light statically, and for the first time realizes multi-mode dynamic tunable color afterglow emission in a single glass body.

[0050] Meanwhile, the transparency of the glass-ceramic material of this invention provides a key material basis for realizing cutting-edge applications such as three-dimensional optical information storage and display; the good thermal stability and high hardness value confirm that the material has good application tolerance in extreme working environments.

[0051] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A photothermal dynamically tunable color-changing long-afterglow luminescent transparent glass-ceramic, characterized in that, The original glass of the transparent glass ceramic is composed of the following molar fractions: 39.5 parts ZnO, 30 parts SiO2, 10 parts Al2O3, 10 parts H3BO3, 6-10 parts K2CO3, 1-4 parts Li2CO3 and 0.5 parts MnCO3.

2. The photothermal dynamically tunable color long afterglow luminescent transparent glass-ceramic according to claim 1, characterized in that, The main crystalline phase of the transparent glass-ceramic is Zn1.7SiO4:Li. Mn 2+ The two emission peaks are located in the Zn1.7SiO4:Li nanocrystalline phase and glass phase, respectively, with the two emission peaks located in the 520-540 nm and 600-650 nm wavelength bands, respectively.

3. The photothermal dynamically tunable color long afterglow luminescent transparent glass-ceramic according to claim 1, characterized in that, The excitation wavelength range of the transparent glass ceramic is 254 nm-380 nm, and the excitation / charging temperature range is 20 ℃-250 ℃.

4. The photothermal dynamically tunable color long afterglow luminescent transparent glass-ceramic according to claim 1, characterized in that, The transparent glass ceramic is excited by laser light of the excitation wavelength at the ambient temperature of the excitation temperature to produce long afterglow emission, and the afterglow color can be changed with the excitation temperature or the excitation wavelength.

5. A method for preparing the photothermal dynamically tunable color-changing long-afterglow luminescent transparent glass-ceramic according to any one of claims 1-4, characterized in that, The method includes the following steps: S1. Weigh out the glass raw materials according to the molar ratio and composition of 39.5 parts ZnO, 30 parts SiO2, 10 parts Al2O3, 10 parts H3BO3, 6-10 parts K2CO3, 1-4 parts Li2CO3 and 0.5 parts MnCO3, mix them and grind them evenly to obtain the mixed raw materials; S2. The mixed raw materials are fully melted in a high-temperature furnace under a reducing atmosphere, cooled and shaped, and then annealed to obtain the original glass. S3. The original glass is heat-treated in a reducing atmosphere and polished to obtain a dynamically tunable color long afterglow luminescent glass-ceramic.

6. The preparation method according to claim 5, characterized in that: In step S2), the melting temperature is 1430-1480 ℃, the time is 40 min, the reducing atmosphere is provided by activated carbon particles, the cooling and molding temperature is 300-350 ℃, and the annealing temperature is 500 ℃.

7. The preparation method according to claim 5, characterized in that: In step S3), the heat treatment temperature is 620-700 ℃, the heating rate is 7 ℃ / min, and the holding time is 120-180 min.

8. The photothermal dynamically tunable color long afterglow luminescent transparent glass ceramic prepared by the method of any one of claims 5-7.

9. A method for producing photothermal dynamically tunable color long-afterglow luminescent transparent glass ceramics based on the method described in any one of claims 5-7, characterized in that: The method is controlled as follows: Within the excitation temperature range of 20℃-80℃, changing the external excitation wavelength from 254 nm to 365 nm causes a reversible change in the afterglow color from green to orange-red due to the bimodal emission intensity change of the transparent glass ceramic; within the wavelength range of 350 nm-380 nm, changing the excitation temperature from 20℃ to 250℃ causes a reversible change in the afterglow color from orange-red to green due to the bimodal emission intensity change of the transparent glass ceramic.

10. The application of the photothermal dynamically tunable color long afterglow luminescent transparent glass-ceramic prepared by the method according to any one of claims 5-7, characterized in that, Applications in information storage and display.

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