A high-temperature long-lasting luminescent material and its preparation method

Abstract

This invention provides an ultra-high temperature long-lasting luminescent material and its preparation method. The ultra-high temperature long-lasting luminescent material is a composite material composed of boron oxide crystals and polycyclic aromatic hydrocarbon molecules. The polycyclic aromatic hydrocarbon molecules are uniformly dispersed in monomolecule form and embedded within the boron oxide crystals, which are translucent crystals formed by in-situ dehydration of boric acid molecules. The ultra-high temperature long-lasting luminescent material of this invention exhibits an extremely high luminescence temperature, reaching up to 400℃. The luminescence color of the ultra-high temperature long-lasting luminescent material of this invention can be adjusted from purple to deep red, and the luminescence wavelength (386-780nm) covers the ultraviolet to near-infrared range, exhibiting time- and temperature-dependent characteristics. The average lifetime of the ultra-high temperature long-lasting luminescent material of this invention can reach 2138ms in a room temperature air environment, and the visually perceptible afterglow time reaches 24s in a room temperature air environment. Furthermore, its long-lasting luminescence performance is stable and it can be stored for extended periods.

Description

Technical Field

[0001] This invention belongs to the field of organic long-lasting luminescent materials, specifically relating to an ultra-high temperature long-lasting luminescent material and its preparation method, particularly a polycyclic aromatic hydrocarbon molecular-based organic ultra-high temperature long-lasting luminescent material, its preparation method, and its application. Background Technology

[0002] Long-lasting luminescent materials have significant application value in fields such as displays, bioimaging, anti-counterfeiting, and data storage [Nat. Rev. Mater. 2020, 5, 869-885]. Long-lasting luminescence under extreme environments, such as ultra-high temperatures, is of great importance for the development of novel optoelectronic integrated devices [Angew. Chem. Int. Ed. 2022, 61, e202208960]. Currently, traditional inorganic phosphors composed of rare-earth ions and transition metal elements have been widely commercialized due to their long emission lifetime and high luminous efficiency [Chem. Soc. Rev. 2016, 45, 2090-2136]. Their long-lasting emission mainly originates from the slow release of trapped charge carriers by impurities, defects, or dopant ions under thermal stimulation. However, the application of these inorganic long-lasting luminescent materials under high-temperature conditions still has many shortcomings, mainly due to the difficulty in precisely controlling the defect distribution, matrix composition, and dopant ions [Nat. Mater. 2017, 16, 543-550].

[0003] Recently, organic molecules and polymers have been widely used in long-lasting luminescent materials due to their good designability and absence of rare metal elements [Nat. Mater. 2015, 14, 685-690]. In these systems, long-lasting emission is mainly based on spin-forbidden triplet exciton group transitions, which initially allowed long-lifetime phosphorescence to be observed only at liquid nitrogen temperatures. Over the past few decades, researchers have developed various strategies, including crystallization, polymerization, host-guest interactions, and heavy atom effects, to achieve long-lived organic phosphorescence in room temperature air environments by promoting intersystem crossings to activate triplet excitons or by suppressing nonradiative transitions to reduce triplet exciton dissipation [Nat. Mater. 2015, 14, 685-690; J. Am. Chem. Soc. 2021, 143, 13675-13685; Angew. Chem. Int. Ed. 2022, 61, e202200236; Angew. Chem. Int. Ed. 2016, 55, 9872-9876]. In addition, thermally activated delayed fluorescence organic long afterglow has also been achieved by controlling the antisystem crosstalk rate constant and the singlet-triplet energy level difference [Angew. Chem. Int. Ed. 2021, 60, 17138-17147]. However, due to the extreme thermal quenching of triplet excitons, these organic long persistent luminescent materials usually cannot survive at high temperatures (>100℃) [Angew. Chem. Int. Ed. 2023, 61, e202205556; Angew. Chem. Int. Ed. 2023, 62, e202302792; Angew. Chem. Int. Ed. 2024, e202318516; Nat. Commun. 2024, 15, 1269]. Summary of the Invention

[0004] The purpose of this invention is to address the problem that organic long-lasting luminescence is difficult to achieve at ultra-high temperatures, and to provide an ultra-high temperature long-lasting luminescent material and its preparation method. In the prior art, only a few organic molecular crystals or composites of organic molecules and polymers can emit long-lasting luminescence at temperatures around 100°C, but it is still difficult to achieve organic long-lasting luminescence at ultra-high temperatures. In contrast, this invention uses polycyclic aromatic hydrocarbons and employs boron oxide crystals as a confining matrix, enabling the realization of various ultra-high temperature long-lasting luminescent materials.

[0005] The objective of this invention can be achieved through the following methods:

[0006] In a first aspect, the present invention provides an ultra-high temperature long-lasting luminescent material, comprising boron oxide crystals and polycyclic aromatic hydrocarbon molecules; wherein the polycyclic aromatic hydrocarbon molecules are uniformly dispersed in the boron oxide crystals in the form of monomolecules.

[0007] As one embodiment of the present invention, the boron oxide crystal is a translucent crystal produced by in-situ dehydration of boric acid molecules.

[0008] In one embodiment of the present invention, the polycyclic aromatic hydrocarbon molecules exist in the boron oxide crystal in a monomolecular dispersion rather than aggregated form. This is determined by the low doping concentration of the polycyclic aromatic hydrocarbon molecules and their good dispersibility in boron oxide; there is no covalent cross-linking between the polycyclic aromatic hydrocarbon molecules and the boron oxide crystal. In the prior art (such as patents: 202211614899.7 and 202111176734.1), composite materials prepared by reacting multifunctional molecules with boric acid are used. At high temperatures, the multifunctional molecules in the composite material continue to undergo carbonization, dehydration, and carboxylation reactions with boric acid. At the same time, the boric acid molecules also continue to decompose to produce water, causing the long afterglow to quench, thus failing to achieve ultra-high temperature long-term continuous luminescence.

[0009] As one embodiment of the present invention, the ultra-high temperature long-lasting luminescent material contains C, N, B, O elements and CC / C=C, CN, BO bonds.

[0010] Secondly, the present invention also provides a method for preparing an ultra-high temperature long-lasting luminescent material, comprising the following steps:

[0011] S1. Mixing of reactants: Dissolve fused-ring aromatic hydrocarbon molecules and boric acid completely in a solvent, heat to evaporate the solvent, and obtain a mixture of fused-ring aromatic hydrocarbon molecules and boric acid;

[0012] S2. Preparation of ultra-high temperature long-lasting luminescent material: The mixture of polycyclic aromatic hydrocarbon molecules and boric acid obtained in step S1 is heated and melted to obtain the ultra-high temperature long-lasting luminescent material.

[0013] In one embodiment of the present invention, in step S1, the polycyclic aromatic hydrocarbon molecule includes 7,8-benzoquinone (4-azaphenanthrene), o-phenanthroline (4,5-diazaphenanthrene), phenanthrene (4,5-diazaphenanthrene), 5,6-benzoquinone (1-azaphenanthrene), 2-aza[4]helicene (2-aza[4]helicene), 4-aza[4]helicene (4-aza[4]helicene), [4]helicene ([4]helicene) One or more of the following: ne), 4,13-diaza[6]helicene, anthra[1,2-f:5,6-f′]diquinoline, benzo[1,2]tetrapheno[8,9-f]quinoline, 4-pyridyl[4]helicene, and 2-pyridyl[4]helicene.

[0014] In one embodiment of the present invention, in step S1, the ratio of the polycyclic aromatic hydrocarbon molecule to boric acid is 1:1000-10000.

[0015] In one embodiment of the present invention, in step S1, the solvent is water. The amount of solvent used is sufficient to completely dissolve the polycyclic aromatic hydrocarbon molecules and boric acid. The purpose of dissolving is to ensure that the polycyclic aromatic hydrocarbon molecules and boric acid are in full contact and mixed uniformly.

[0016] In one embodiment of the present invention, in step S1, the heating temperature is 80-90℃, and the time is 9-12 hours. Specifically, the heating involves placing a solution of polycyclic aromatic hydrocarbon (PAH) molecules and boric acid in a container and heating it openly. Heating allows the solvent to completely evaporate, preventing it from participating in the reaction and ensuring a uniform mixture of PAH molecules and boric acid. To prevent rapid evaporation of the solvent during the melting reaction, which could lead to boiling over, the solvent is removed before the reaction. Dissolving the PAH molecules and boric acid before evaporating the solvent allows for sufficient contact and uniform mixing, ensuring the PAH molecules are uniformly dispersed within the boron oxide crystals. The heating temperature should not be too high, which could cause boiling over, nor too low, which would result in slow evaporation. The evaporation time depends on whether the solvent has completely evaporated.

[0017] In one embodiment of the present invention, in step S2, the heating and melting temperature is 250-300°C, and the heating reaction time is 48-72 hours. The heating and melting temperature should be higher than the melting point of boric acid, allowing the boric acid to fully decompose into boron oxide. Increasing the reaction time and reaction temperature can accelerate the conversion of boric acid to boron oxide. The present invention mainly regulates the degree of boric acid conversion to boron oxide by controlling the reaction temperature, thereby obtaining a high-rigidity and thermally stable boron oxide crystal. Methods that achieve the same effect as the present invention by controlling the reaction time are also within the scope of protection of the present invention. In addition, during the open heating and melting reaction, the solvent generated by the reaction will evaporate, ultimately yielding a solid product. The solid boron oxide crystal can restrict the rotation and vibration of polycyclic aromatic hydrocarbon molecules and prevent oxygen quenching in the air.

[0018] As one embodiment of the present invention, by changing the type of polycyclic aromatic hydrocarbon molecules in step S1, a variety of ultra-high temperature long-lasting luminescent materials with different long-lasting luminescence colors are obtained. The luminescence color of the ultra-high temperature long-lasting luminescent materials can be adjusted from purple to deep red, with a maximum emission peak wavelength range of 386-780 nm, covering the ultraviolet to near-infrared region, and exhibiting time- and temperature-dependent characteristics.

[0019] As one embodiment of the present invention, the luminescence temperature of the ultra-high temperature long-continuous luminescence material is as high as 400°C.

[0020] As one embodiment of the present invention, the average lifetime of the ultra-high temperature long-lasting luminescent material can reach 2138ms in a room temperature air environment, and the afterglow time that can be perceived by the naked eye can reach 24s in a room temperature air environment.

[0021] Thirdly, this invention also provides an application of ultra-high temperature long-continuous luminescent material in three-dimensional visualization temperature sensing, anti-counterfeiting, and information encryption.

[0022] Compared with the prior art, the advantages of the present invention include:

[0023] 1) The ultra-high temperature long-lasting luminescent material provided by this invention can emit a full-color ultra-high temperature afterglow that is visible to the naked eye after ultraviolet lamp irradiation is stopped, with a temperature reaching 400℃; the afterglow color ranges from purple to red, and the maximum emission peak ranges from 386nm to 780nm, covering the ultraviolet to near-infrared region, and exhibits time- and temperature-dependent characteristics. The average lifetime of the ultra-high temperature long-lasting luminescent material can reach 2138ms in a room temperature air environment, and the visually perceptible afterglow time reaches 24s in a room temperature air environment, and the long-lasting luminescence performance is stable, allowing for long-term storage;

[0024] 2) The preparation method of the ultra-high temperature long-term continuous luminescent material provided by the present invention is simple, fast and universal, without the need for complex and expensive equipment and harsh operating environment, with low preparation cost and easy to realize industrial production;

[0025] 3) The ultra-high temperature long-term continuous luminescent material provided by this invention has great potential application value in the fields of anti-counterfeiting, optoelectronics, photovoltaics, and photocatalysis. Attached Figure Description

[0026] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0027] Figure 1 This is a schematic diagram illustrating the preparation of the ultra-high temperature long-lasting luminescent materials obtained in Examples 1-12 of the present invention;

[0028] Figure 2 These are luminescence photographs of the ultra-high temperature long-lasting luminescent materials obtained in Examples 1-12 of this invention at different temperatures and delay times after the removal of 365nm ultraviolet excitation light;

[0029] Figure 3 The temperature-dependent delayed emission spectrum of the ultra-high temperature long-lasting luminescent material obtained in Example 5 of this invention is shown.

[0030] Figure 4 The steady-state and delayed emission spectra of the ultra-high temperature long-lasting luminescent material obtained in Example 5 of the present invention and the dilute solution of the polycyclic aromatic hydrocarbon molecule used in Example 5 of the present invention at a low temperature of 77K are shown.

[0031] Figure 5 The X-ray diffraction pattern of the ultra-high temperature long-lasting luminescent material obtained in Example 5 of this invention is shown below.

[0032] Figure 6 The Fourier transform infrared spectrum of the ultra-high temperature long-lasting luminescent material obtained in Example 5 of this invention;

[0033] Figure 7 The X-ray photoelectron spectrum of the ultra-high temperature long-lasting luminescent material obtained in Example 5 of the present invention is shown; where a is the B1s spectrum, b is the O1s spectrum, c is the C1s spectrum, and d is the N1s spectrum.

[0034] Figure 8 The images show the steady-state and delayed emission spectra of the ultra-high temperature long-lasting luminescent materials obtained in Examples 1-6 of this invention; where a is the emission spectrum of Example 1, b is the emission spectrum of Example 2, c is the emission spectrum of Example 3, d is the emission spectrum of Example 4, e is the emission spectrum of Example 5, and f is the emission spectrum of Example 6.

[0035] Figure 9The images show the steady-state and delayed emission spectra of the ultra-high temperature long-lasting luminescent materials obtained in Examples 7-12 of this invention; where a is the emission spectrum of Example 7, b is the emission spectrum of Example 8, c is the emission spectrum of Example 9, d is the emission spectrum of Example 10, e is the emission spectrum of Example 11, and f is the emission spectrum of Example 12.

[0036] Figure 10 These are time-resolved emission decay curves of the ultra-high temperature long-continuous luminescent materials obtained in Examples 1-6 of the present invention; wherein, a is the time-resolved emission decay curve of Example 1, b is the time-resolved emission decay curve of Example 2, c is the time-resolved emission decay curve of Example 3, d is the time-resolved emission decay curve of Example 4, e is the time-resolved emission decay curve of Example 5, and f is the time-resolved emission decay curve of Example 6.

[0037] Figure 11 The following are time-resolved emission decay curves of the ultra-high temperature long-continuous luminescent materials obtained in Examples 7-12 of the present invention; wherein, a is the time-resolved emission decay curve of Example 7, b is the time-resolved emission decay curve of Example 8, c is the time-resolved emission decay curve of Example 9, d is the time-resolved emission decay curve of Example 10, e is the time-resolved emission decay curve of Example 11, and f is the time-resolved emission decay curve of Example 12. Detailed Implementation

[0038] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0039] This invention utilizes polycyclic aromatic hydrocarbon molecules and boric acid to prepare ultra-high temperature long-lasting luminescent materials, such as... Figure 1 As shown, polycyclic aromatic hydrocarbon molecules and boric acid are completely dissolved, and then the solvent is completely evaporated to obtain a mixture of polycyclic aromatic hydrocarbon molecules and boric acid. The mixture is then heated and melted until the boric acid decomposes completely to obtain an ultra-high temperature long-lasting luminescent material with a long-lasting luminescence temperature as high as 400℃. By changing the type of polycyclic aromatic hydrocarbon molecules, a variety of ultra-high temperature long-lasting luminescent materials with luminescence colors ranging from purple to red are obtained.

[0040] Example 1

[0041] 100 mg of boric acid and 0.1 mg of polycyclic aromatic hydrocarbon molecule 1 (4-azaphenanthrene, 7,8-benzoquinoline) were added to a 4 mL glass bottle containing 3 mL of deionized water. After initial dissolution, the glass bottle was placed open in a heating block and heated at 90 °C on a heating platform to fully dissolve the boric acid and 7,8-benzoquinoline in the water. Heating was continued overnight (12 h) to completely evaporate the deionized water, yielding a mixture a of 7,8-benzoquinoline and boric acid.

[0042] A mixture of 7,8-benzoquinoline and boric acid was heated to melt at 250°C and cooled to room temperature after 48 hours to obtain a blocky white translucent crystal (1), namely, an ultra-high temperature long-lasting luminescent material 1.

[0043] Figure 2 The images show the luminescence of the ultra-high temperature long-lasting luminescent material 1 (polycyclic aromatic hydrocarbon molecule 1) obtained in this embodiment at different temperatures and delay times after the removal of 365nm ultraviolet excitation light, demonstrating that it can still emit a deep blue long afterglow at an ultra-high temperature of 250℃.

[0044] Example 2

[0045] 100 mg of boric acid and 0.1 mg of polycyclic aromatic hydrocarbon molecule 2 (4,5-diazaphenanthrene, o-phenanthroline) were added to a 4 mL glass bottle containing 3 mL of deionized water. After initial dissolution, the glass bottle was placed open in a heating block and heated at 90 °C on a heating platform to fully dissolve the boric acid and o-phenanthroline in the water. Heating was continued overnight (12 h) to allow the deionized water to completely evaporate, resulting in a mixture b of o-phenanthroline and boric acid.

[0046] A mixture of o-phenanthroline and boric acid b was heated to molten at 250℃ and cooled to room temperature after 48h to obtain a blocky white translucent crystal (2), namely the ultra-high temperature long-lasting luminescent material 2.

[0047] Figure 2 The images show the luminescence of the ultra-high temperature long-lasting luminescent material 2 (polycyclic aromatic hydrocarbon molecule 2) obtained in this embodiment at different temperatures and delay times after the removal of 365nm ultraviolet excitation light, demonstrating that it can still emit a deep blue long afterglow at an ultra-high temperature of 330℃.

[0048] Example 3

[0049] 100 mg of boric acid and 0.1 mg of polycyclic aromatic hydrocarbon molecule 3 (4,5-diazaphenanthrene, phenanthrene) were added to a 4 mL glass bottle containing 3 mL of deionized water. After initial dissolution, the glass bottle was placed open in a heating block and heated at 90 °C on a heating platform to fully dissolve the boric acid and phenanthrene in the water. Heating was continued overnight (12 h) to allow the deionized water to completely evaporate, resulting in a mixture c of phenanthrene and boric acid.

[0050] The mixture of phenanthridine and boric acid c was heated to molten at 250℃ and cooled to room temperature after 48h to obtain a blocky white translucent crystal (3), namely the ultra-high temperature long-lasting luminescent material 3.

[0051] Figure 2 The images show the luminescence of the ultra-high temperature long-lasting luminescent material 3 (polycyclic aromatic hydrocarbon molecule 3) obtained in this embodiment at different temperatures and delay times after the removal of 365nm ultraviolet excitation light, demonstrating that it can still emit a long purple afterglow at an ultra-high temperature of 340℃.

[0052] Example 4

[0053] 100 mg of boric acid and 0.1 mg of polycyclic aromatic hydrocarbon molecule 4 (1-azaphenanthrene, 5,6-benzoquinoline) were added to a 4 mL glass bottle containing 3 mL of deionized water. After initial dissolution, the glass bottle was placed open in a heating block and heated at 90 °C on a heating platform to fully dissolve the boric acid and 5,6-benzoquinoline in the water. Heating was continued overnight (12 h) to allow the deionized water to completely evaporate, yielding a mixture d of 5,6-benzoquinoline and boric acid.

[0054] A mixture of 5,6-benzoquinoline and boric acid was heated and melted at 250℃, and cooled to room temperature after 48h to obtain a blocky white translucent crystal (4), namely the ultra-high temperature long-lasting luminescent material 4.

[0055] Figure 2 The images show the luminescence of the ultra-high temperature long-lasting luminescent material 4 (polycyclic aromatic hydrocarbon molecule 4) obtained in this embodiment at different temperatures and delay times after the removal of 365nm ultraviolet excitation light, demonstrating that it can still emit a deep blue long afterglow at an ultra-high temperature of 330℃.

[0056] Example 5

[0057] 100 mg of boric acid and 0.1 mg of polycyclic aromatic hydrocarbon molecule 5 (2-aza[4]helicene, 2-aza[4]helicene) were added to a 4 mL glass bottle containing 3 mL of deionized water. After initial dissolution, the glass bottle was placed open in a heating block and heated at 90 °C on a heating platform to fully dissolve boric acid and 2-aza[4]helicene in water. Heating was continued overnight (12 h) to allow the deionized water to completely evaporate, resulting in a mixture e of 2-aza[4]helicene and boric acid.

[0058] A mixture of 2-aza[4]spiroene and boric acid was heated and melted at 250℃, and cooled to room temperature after 48h to obtain a blocky white translucent crystal (5), namely, an ultra-high temperature long-lasting luminescent material 5.

[0059] Figure 2The images show the emission of the ultra-high temperature long-lasting luminescent material 5 (polycyclic aromatic hydrocarbon molecule 5) obtained in this embodiment at different temperatures and delay times after the removal of 365nm ultraviolet excitation light, demonstrating that it can still emit a long blue afterglow at an ultra-high temperature of 400℃. Figure 3 The image shows the temperature-dependent delayed emission spectrum of the ultra-high temperature long-lasting luminescent material 5 obtained in this embodiment. The delayed emission spectrum mainly consists of two emission peaks, located at 455 nm and 560 nm, respectively. The emission peak at 560 nm has a shoulder peak at a position of 528 nm. The two delayed emission peaks are attributed to thermally activated delayed fluorescence and phosphorescence, respectively. Figure 4 The image shows the steady-state and delayed emission spectra of the ultra-high temperature long-lasting luminescent material 5 and the fused ring aromatic molecule 2 azirospirene [4] at a low temperature of 77K. It can be seen from the image that the luminescence source of the prepared ultra-high temperature long-lasting luminescent material is the monomolecular dispersed fused ring aromatic molecule rather than its aggregate. Figure 5 , 6 Figures 7 and 8 show the X-ray diffraction pattern, Fourier transform infrared spectrum, and X-ray photoelectron spectrum of the ultra-high temperature long-lasting luminescent material 5 obtained in this embodiment, respectively. As can be seen from the figures, the prepared ultra-high temperature long-lasting luminescent material is a complex of boron oxide crystal and polycyclic aromatic hydrocarbon molecules. The boron oxide crystal is a blocky semi-transparent crystal produced by in-situ dehydration of boric acid molecules. There is no covalent cross-linking between the polycyclic aromatic hydrocarbon molecules and the boron oxide crystal.

[0060] Example 6

[0061] 100 mg of boric acid and 0.1 mg of polycyclic aromatic hydrocarbon molecule 6 (4-aza[4]helicene) were added to a 4 mL glass bottle containing 3 mL of deionized water. After initial dissolution, the glass bottle was placed open in a heating block and heated at 90 °C on a heating platform to fully dissolve the boric acid and 4-aza[4]helicene in the water. Heating was continued overnight (12 h) to completely evaporate the deionized water, resulting in a mixture f of 4-aza[4]helicene and boric acid.

[0062] A mixture of 4-aza[4]spirolene and boric acid was heated to melt at 250℃ and cooled to room temperature after 48h to obtain a blocky pale yellow translucent crystal (6), namely the ultra-high temperature long-lasting luminescent material 6.

[0063] Figure 2 The images show the luminescence of the ultra-high temperature long-lasting luminescent material 6 (polycyclic aromatic hydrocarbon molecule 6) obtained in this embodiment at different temperatures and delay times after the removal of 365nm ultraviolet excitation light, demonstrating that it can still emit a long blue-green afterglow at an ultra-high temperature of 380℃.

[0064] Example 7

[0065] 100 mg of boric acid and 0.1 mg of polycyclic aromatic hydrocarbon molecule 7 ([4]helicene, [4]spirolene) were added to a 4 mL glass bottle containing 3 mL of deionized water. After initial dissolution, the glass bottle was placed open in a heating block and heated at 90 °C on a heating platform to fully dissolve the boric acid and [4]spirolene in the water. Heating was continued overnight (12 h) to completely evaporate the deionized water, resulting in a mixture of [4]spirolene and boric acid g.

[0066] A mixture of helene and boric acid g was heated and melted at 250℃[4] and cooled to room temperature after 48h to obtain a blocky white translucent crystal (7), namely, an ultra-high temperature long-lasting luminescent material 7.

[0067] Figure 2 The images show the emission of the ultra-high temperature long-lasting luminescent material 7 (polycyclic aromatic hydrocarbon molecule 7) obtained in this embodiment at different temperatures and delay times after the removal of 365nm ultraviolet excitation light, demonstrating that it can still emit a long blue afterglow at an ultra-high temperature of 330℃.

[0068] Example 8

[0069] 100 mg of boric acid and 0.1 mg of polycyclic aromatic hydrocarbon molecule 8 (4,13-diaza[6]helicene, 4,13-diaza[6]helicene) were added to a 4 mL glass bottle containing 3 mL of deionized water. After initial dissolution, the glass bottle was placed open in a heating block and heated at 90 °C on a heating platform to fully dissolve the boric acid and 4,13-diaza[6]helicene in the water. Heating was continued overnight (12 h) to completely evaporate the deionized water, resulting in a mixture h of 4,13-diaza[6]helicene and boric acid.

[0070] A mixture of 4,13 diaza[6]spirolene and boric acid was heated and melted at 250°C for 48 hours and then cooled to room temperature to obtain a blocky, pale yellow, translucent crystal (8), which is an ultra-high temperature long-lasting luminescent material 8.

[0071] Figure 2 The images show the luminescence of the ultra-high temperature long-lasting luminescent material 8 (polycyclic aromatic hydrocarbon molecule 8) obtained in this embodiment at different temperatures and delay times after the removal of 365nm ultraviolet excitation light, demonstrating that it can still emit a long green afterglow at an ultra-high temperature of 350℃.

[0072] Example 9

[0073] 100 mg of boric acid and 0.1 mg of polycyclic aromatic hydrocarbon molecule 9 (anthra[1,2-f:5,6-f′]diquinoline, diaza-S-type[7]helicene) were added to a 4 mL glass bottle containing 3 mL of deionized water. After initial dissolution, the glass bottle was placed open in a heating block and heated at 90 °C on a heating platform to fully dissolve the boric acid and diaza-S-type[7]helicene in the water. Heating was continued overnight (12 h) to completely evaporate the deionized water, resulting in a mixture of diaza-S-type[7]helicene and boric acid.

[0074] A mixture of diaza-type S-type[7]spirolene and boric acid was heated and melted at 250℃, and cooled to room temperature after 48h to obtain a blocky pale yellow translucent crystal (9), namely, an ultra-high temperature long-lasting luminescent material 9.

[0075] Figure 2 The images show the emission of the ultra-high temperature long-lasting luminescent material 9 (polycyclic aromatic hydrocarbon molecule 9) obtained in this embodiment at different temperatures and delay times after the removal of 365nm ultraviolet excitation light, showing that it can still emit a long yellow-green afterglow at an ultra-high temperature of 370℃.

[0076] Example 10

[0077] 100 mg of boric acid and 0.1 mg of polycyclic aromatic hydrocarbon molecule 10 (benzo[1,2]tetrapheno[8,9-f]quinoline, aza-S-type[7]spirolene) were added to a 4 mL glass bottle containing 3 mL of deionized water. After initial dissolution, the glass bottle was placed open in a heating block and heated at 90 °C on a heating platform to fully dissolve the boric acid and aza-S-type[7]spirolene in the water. Heating was continued overnight (12 h) to completely evaporate the deionized water, resulting in a mixture of aza-S-type[7]spirolene and boric acid.

[0078] A mixture of fused azide S-type[7]spiroene and boric acid was heated at 250°C and cooled to room temperature after 48 hours to obtain a blocky, pale yellow, translucent crystal (10), which is an ultra-high temperature long-lasting luminescent material 10.

[0079] Figure 2 The images show the emission of the ultra-high temperature long-lasting luminescent material 10 (polycyclic aromatic hydrocarbon molecule 10) obtained in this embodiment at different temperatures and delay times after the removal of 365nm ultraviolet excitation light, demonstrating that it can still emit a long yellow afterglow at an ultra-high temperature of 350℃.

[0080] Example 11

[0081] 100 mg of boric acid and 0.1 mg of polycyclic aromatic hydrocarbon molecule 11 (4-(4-pyridyl)[4]helicene, 4-pyridine[4]helicene) were added to a 4 mL glass bottle containing 3 mL of deionized water. After initial dissolution, the glass bottle was placed open in a heating block and heated at 90 °C on a heating platform to fully dissolve the boric acid and 4-pyridine[4]helicene in the water. Heating was continued overnight (12 h) to allow the deionized water to evaporate completely, resulting in a mixture k of 4-pyridine[4]helicene and boric acid.

[0082] A mixture of 4-pyridine[4]spiroene and boric acid was heated to melt at 250°C and cooled to room temperature after 48 hours to obtain a blocky pale yellow translucent crystal (11), namely the ultra-high temperature long-lasting luminescent material 11.

[0083] Figure 2 The images show the luminescence of the ultra-high temperature long-lasting luminescent material 11 (polycyclic aromatic hydrocarbon molecule 11) obtained in this embodiment at different temperatures and delay times after the removal of 365nm ultraviolet excitation light, demonstrating that it can still emit a long blue-green afterglow at an ultra-high temperature of 400℃.

[0084] Example 12

[0085] 100 mg of boric acid and 0.1 mg of polycyclic aromatic hydrocarbon molecule 12 (2-(4-pyridyl)[4]helicene, 2-pyridine[4]helicene) were added to a 4 mL glass bottle containing 3 mL of deionized water. After initial dissolution, the glass bottle was placed open in a heating block and heated at 90 °C on a heating platform to fully dissolve boric acid and 2-pyridine[4]helicene in water. Heating was continued overnight (12 h) to completely evaporate the deionized water, resulting in a mixture l of 2-pyridine[4]helicene and boric acid.

[0086] A mixture of 2-pyridine[4]spiroene and boric acid was heated to melt at 250℃ and cooled to room temperature after 48h to obtain a blocky pale yellow translucent crystal (12), namely the ultra-high temperature long continuous luminescent material 12.

[0087] Figure 2 The images show the luminescence of the ultra-high temperature long-lasting luminescent material 12 (polycyclic aromatic hydrocarbon molecule 12) obtained in this embodiment at different temperatures and delay times after the removal of 365nm ultraviolet excitation light, demonstrating that it can still emit a long blue-green afterglow at an ultra-high temperature of 400℃.

[0088] Example 13

[0089] 100 mg of boric acid and 0.01 mg of polycyclic aromatic hydrocarbon molecule 12 (2-(4-pyridyl)[4]helicene, 2-pyridine[4]helicene) were added to a 4 mL glass bottle containing 3 mL of deionized water. After initial dissolution, the glass bottle was placed open in a heating block and heated at 90 °C on a heating platform to fully dissolve boric acid and 2-pyridine[4]helicene in water. Heating was continued overnight (12 h) to allow the deionized water to completely evaporate, resulting in a mixture m of 2-pyridine[4]helicene and boric acid.

[0090] A mixture of pyridine[4]spiroene and boric acid was heated to melt at 250°C and cooled to room temperature after 48 hours to obtain a blocky pale yellow translucent crystal (13), namely the ultra-high temperature long-lasting luminescent material 13, which can still emit a long blue-green afterglow at an ultra-high temperature of 400°C.

[0091] Comparative Example 1

[0092] 10 mg of boric acid and 10 mg of polycyclic aromatic hydrocarbon molecule 5 (2-aza[4]helicene, 2-aza[4]helicene) were added to a 4 mL glass bottle containing 3 mL of deionized water. After initial dissolution, the glass bottle was placed open in a heating block and heated at 90 °C on a heating platform to fully dissolve boric acid and 2-aza[4]helicene in water. Heating was continued overnight (12 h) to allow the deionized water to completely evaporate, resulting in a mixture n of 2-aza[4]helicene and boric acid.

[0093] A mixture of 2-aza[4]spirolene and boric acid was heated to melt at 250°C and cooled to room temperature after 48 hours to obtain a blocky white crystalline substance (14).

[0094] Excessive use of polycyclic aromatic hydrocarbon molecules causes molecular aggregation, leading to the disappearance of long-lasting luminescence.

[0095] Comparative Example 2

[0096] Add 100 mg of boric acid and 0.1 mg of citric acid to a 4 mL glass bottle containing 3 mL of deionized water. After initial dissolution, place the glass bottle open in a heating block and heat it at 90 °C on a heating platform to fully dissolve the boric acid and citric acid in the water. Continue heating overnight (12 h) to allow the deionized water to completely evaporate, resulting in a mixture of citric acid and boric acid.

[0097] A mixture of citric acid and boric acid was heated to molten state at 250°C and cooled to room temperature after 48 hours to obtain a blocky brown translucent crystal (15).

[0098] Citric acid reacts with boric acid and carbonizes during heating, causing the product to fail to emit a long afterglow.

[0099] Comparative Example 3

[0100] 100 mg of boric acid and 0.1 mg of polycyclic aromatic hydrocarbon molecule 5 (2-aza[4]helicene, 2-aza[4]helicene) were added to a 4 mL glass bottle containing 3 mL of deionized water. After initial dissolution, the glass bottle was placed open in a heating block and heated at 90 °C on a heating platform to fully dissolve the boric acid and 2-aza[4]helicene in the water. Heating was continued overnight (12 h) to completely evaporate the deionized water, resulting in a mixture p of 2-aza[4]helicene and boric acid.

[0101] A mixture of 2-aza[4]spirolene and boric acid was heated at 100°C for 48 h and then cooled to room temperature to obtain a white powder product (16).

[0102] Boric acid does not decompose into boron oxide. At high temperatures, boric acid undergoes cracking to produce water, causing the long afterglow to disappear at lower temperatures.

[0103] Application effect verification:

[0104] Figure 2 The images show the luminescence of the ultra-high temperature long-lasting luminescent materials obtained in Examples 1-12 at different temperatures and delay times after the removal of 365nm ultraviolet excitation light. As can be seen from the images, the luminescence color of the prepared ultra-high temperature long-lasting luminescent materials can be adjusted from purple to deep red, and has time and temperature dependent characteristics. The afterglow time that can be seen with the naked eye reaches 24s in a room temperature air environment, and it can still emit multi-colored long afterglow at an ultra-high temperature of 400℃.

[0105] Figure 5-7 The X-ray diffraction pattern, Fourier transform infrared spectrum, and X-ray photoelectron spectrum of the ultra-high temperature long-lasting luminescent material 5 obtained in Example 5 are shown in the figure. It can be seen from the figure that the prepared ultra-high temperature long-lasting luminescent material contains C, N, B, O elements and CC / C=C, CN, and BO bonds.

[0106] Figure 8 and 9 The figures show the steady-state and delayed emission spectra of the ultra-high temperature long-lasting luminescent materials obtained in Examples 1-12. It can be seen from the figures that the maximum emission peak wavelength range of the prepared ultra-high temperature long-lasting luminescent materials is 386-780 nm, covering the ultraviolet to near-infrared region.

[0107] Figure 10 and 11 The graph shows the time-resolved emission decay curves of the ultra-high temperature long-lasting luminescent materials obtained in Examples 1-12. It can be seen from the graph that the average lifetime of the prepared ultra-high temperature long-lasting luminescent materials can reach 2138 ms in a room temperature air environment.

[0108] This invention has many specific applications, and the above description is only a preferred embodiment. It should be noted that the above embodiments are for illustrative purposes only and are not intended to limit the scope of protection of this invention. For those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A high-temperature, long-lasting luminescent material, characterized in that, It includes boron oxide crystals and polycyclic aromatic hydrocarbon molecules; the polycyclic aromatic hydrocarbon molecules are uniformly dispersed in the boron oxide crystals in the form of monomolecules; The polycyclic aromatic hydrocarbon molecules include one or more of the following: 7,8-benzoquinoline, o-phenanthroline, phenanthridine, 5,6-benzoquinoline, 2-aza[4]spirene, 4-aza[4]spirene, [4]spirene, 4,13-diaza[6]spirene, diazaS-type[7]spirene, azaS-type[7]spirene, 4-pyridine[4]spirene, and 2-pyridine[4]spirene; The ratio of the polycyclic aromatic hydrocarbon molecule to boric acid is 1:1000-10000.

2. The ultra-high temperature long-lasting luminescent material according to claim 1, characterized in that, The boron oxide crystal is a translucent crystal produced by in-situ dehydration of boric acid molecules.

3. The ultra-high temperature long-lasting luminescent material according to claim 1, characterized in that, The ultra-high temperature long-term continuous luminescent material contains C, N, B, and O elements, as well as CC / C=C, CN, and BO bonds.

4. A method for preparing the ultra-high temperature long-lasting luminescent material as described in claim 1, characterized in that, Includes the following steps: S1. Mixing of reactants: The polycyclic aromatic hydrocarbon molecules and boric acid are completely dissolved in a solvent, and the solvent is evaporated by heating to obtain a mixture of polycyclic aromatic hydrocarbon molecules and boric acid. S2. Preparation of ultra-high temperature long-lasting luminescent materials: The mixture of polycyclic aromatic hydrocarbon molecules and boric acid obtained in step S1 is heated and melted to obtain the ultra-high temperature long-lasting luminescent material.

5. The preparation method according to claim 4, characterized in that, In step S1, the heating temperature is 80-90 °C and the heating time is 9-12 h.

6. The preparation method according to claim 4, characterized in that, In step S2, the heating and melting temperature is 250-300°C, and the heating reaction time is 48-72 h.

7. The preparation method according to claim 4, characterized in that, By changing the type of polycyclic aromatic hydrocarbon molecules in step S1, a variety of ultra-high temperature long-lasting luminescent materials with different long-lasting luminescent colors can be obtained.

8. The application of the ultra-high temperature long-continuous luminescent material as described in claim 1 in three-dimensional visualization temperature sensing, anti-counterfeiting, and information encryption.

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