Super-strained pva / sao composite fluorescent material and preparation method thereof

Abstract

This invention discloses a PVA / SrAl2O4:Eu composite with excellent stress performance. 2+ ,Dy 3+ This composite material uses PVA as a matrix and innovatively combines it with SrAl2O4:Eu 2+ ,Dy 3+ By combining pure-phase phosphors, a composite thin film material with water resistance, high brightness, and strong mechanical properties can be synthesized. This method overcomes the shortcomings of powders in terms of flexibility and structural integrity, making them more suitable for mechanical applications.

Description

Technical Field

[0001] This invention discloses a PVA / SrAl2O4:Eu composite material exhibiting excellent strain properties. 2+ ,Dy 3+ (PVA / SAO) composite material and its preparation method: This material is prepared by adjusting the appropriate PVA:SrAl2O4:Eu... 2+ ,Dy 3+ By adjusting the PVA:SAO ratio, different strain properties of PVA / SrAl2O4:Eu were obtained. 2+ ,Dy 3+ Long afterglow composite luminescent materials; this technology belongs to the field of optoelectronic functional materials. Background Technology

[0002] Rare-earth-doped long-afterglow luminescent materials have been widely used in a range of fields, including emergency lighting, near-infrared bioimaging, anti-counterfeiting, and metal flaw detection. Among the many material systems, rare-earth-doped strontium aluminate long-afterglow materials stand out due to their superior properties such as high photoluminescence intensity and long afterglow lifetime, as well as their simple and mature preparation process, making them highly favored in the research field.

[0003] Although a large amount of research focuses on SrAl2O4:Eu 2+ ,Dy 3+ The synthesis, phosphorescence mechanism, and polymer coating of phosphors were investigated, revealing many excellent luminescent properties. However, SrAl2O4:Eu 2+ ,Dy 3+ Phosphors are brittle ceramic materials with low fracture toughness, making them prone to cracking under mechanical stress, vibration, or impact. Abrasion and spalling of the particle surface can occur, leading to surface defects and a decrease in luminescent performance. More importantly, in the absence of a protective polymer matrix, SrAl2O4:Eu 2+ ,Dy 3+ The powder lacks flexibility and structural integrity, making it unsuitable for strain stress applications. In 2010, SBMishra et al. successfully synthesized SrAl2O4:Eu 2+ ,Dy 3+ The composite of long-afterglow phosphors with EVA polymers can produce samples with relatively low strength, which is still insufficient for applications requiring high mechanical strength. In 2020, P. Jha et al. proposed combining SrAl2O4:Eu... 2+ ,Dy 3+ While loading phosphors into PDMS solves the environmental stability problem, PDMS and hydrophilic SrAl2O4:Eu 2 + ,Dy 3+Phosphors inherently possess interfacial incompatibility, resulting in weak interfacial bonding. Under high-energy impacts, this easily leads to phosphor detachment or interfacial debonding, significantly limiting their lifespan. In recent years, few researchers have integrated long-afterglow materials into polymers to enhance mechanical properties. This is due to the complex preparation process, difficulties in sample encapsulation, the tendency of phosphors to agglomerate, and low tensile strength.

[0004] Therefore, this invention develops a SrAl2O4:Eu material that exhibits excellent stress performance. 2+ ,Dy 3+ Novel composite materials with long afterglow luminescence are expected to advance the development of SrAl2O4:Eu 2+ ,Dy 3+ Long-afterglow luminescent materials are of great significance in the field of optoelectronic functional materials. Summary of the Invention

[0005] This study successfully prepared a PVA / SrAl2O4:Eu compound with excellent stress response performance. 2+ ,Dy 3+ Long-afterglow luminescent composite material. Its preparation process is as follows: First, using SrCO3, Al2O3, Eu2O3, and Dy2O3 as raw materials, and H3BO3 as a flux, calcination is carried out at 1200~1400°C under a carbon atmosphere protection with a heating rate of 5°C / min to synthesize high-brightness SrAl2O4:Eu 2+ ,Dy 3+ Powder. Then, 1-3 grams of PVA are dissolved in an appropriate amount of warm distilled water and stirred at 75°C to form a transparent solution. Next, the phosphor prepared above is added to the PVA solution and stirred thoroughly to form a uniform viscous gel. Finally, the gel is poured into a mold and dried to obtain a composite film material that is both flexible and translucent.

[0006] This invention combines PVA with SrAl2O4:Eu 2+ ,Dy 3+ The composite of long-afterglow luminescent materials not only effectively solves the core problems of phosphors being easily hydrolyzed and having poor environmental stability, but also successfully expands the application of this material from traditional signage and lighting to the emerging field of strain-stress sensing. Attached Figure Description

[0007] Figure 1 This invention synthesizes SrAl2O4:Eu 2+ ,Dy 3+ XRD pattern of the composite material.

[0008] Figure 2 This invention synthesizes SrAl2O4:Eu 2+ ,Dy 3+Scanning electron microscope image of the composite material.

[0009] Figure 3 This invention synthesizes SrAl2O4:Eu 2+ ,Dy 3+ Excitation spectrum of the composite material.

[0010] Figure 4 This invention synthesizes SrAl2O4:Eu 2+ ,Dy 3+ Emission spectrum of the composite material.

[0011] Figure 5 This invention synthesizes SrAl2O4:Eu 2+ ,Dy 3+ Afterglow decay curve of composite material.

[0012] Figure 6 This invention synthesizes SrAl2O4:Eu 2+ ,Dy 3+ Tensile strength measurement results of composite materials prepared at different proportions.

[0013] Figure 7 This invention synthesizes SrAl2O4:Eu 2+ ,Dy 3+ Temperature-dependent fluorescence emission spectra of composite materials. Detailed Implementation

[0014] In this invention, SrAl2O4:Eu 2+ ,Dy 3+ The detailed manufacturing process of composite materials is described below: (1) This invention uses PVA, SrCO3, Al2O3, Eu2O3, and Dy2O3 as raw materials, and H3BO3 as a flux. The reaction mixture is based on the ratio of SrAl2O4:Eu... 2+ ,Dy 3+ The stoichiometric ratio of each raw material is used to calculate the amount of each raw material. The amount of flux H3BO3 added is 0~20%, and the amount of PVA is 1~3 grams.

[0015] (2) According to the stoichiometric ratio for preparing 2g of phosphor, weigh the corresponding amounts of SrCO3, Al2O3, Eu2O3, Dy2O3 and H3BO3 raw materials using a precision electronic balance, and mix and grind them thoroughly.

[0016] (3) Place the uniformly mixed powder raw material in a corundum crucible and then place it in a muffle furnace. Under the protection of a flowing carbon reducing atmosphere, heat the material to 1200°C~1400°C at a heating rate of 5°C / min and calcine it at this temperature for 1-5 hours.

[0017] (4) After calcination, the sintered body was naturally cooled to room temperature in the furnace. After grinding and sieving, a high-brightness, pure-phase SrAl2O4:Eu was obtained. 2+ ,Dy 3+ Fluorescent powder.

[0018] (5) Weigh 1-3 grams of PVA particles into a beaker and add 15 ml of distilled water. Place the beaker in a 75°C water bath or on a magnetic stirrer and stir continuously until the PVA is completely dissolved to form a transparent and homogeneous solution.

[0019] (6) The phosphor prepared in step (4) is gradually added to the above PVA solution at a mass ratio of PVA to phosphor of 1:1 to 1:4, and stirred continuously at 75°C for 15 min until a uniformly dispersed viscous gel is formed.

[0020] (7) Pour the obtained uniform gel into a flat mold or petri dish and dry it at room temperature for 24-48 hours. After the moisture has completely evaporated, the PVA / SrAl2O4:Eu gel, which is both flexible and translucent, can be peeled off. 2+ ,Dy 3+ Composite thin film materials.

[0021] Figure 1 The SrAl2O4:Eu prepared in this invention 2+ ,Dy 3+ The XRD patterns of the composite material samples, compared with the diffraction peaks of the standard card PDF#34-0379, indicate that different ratios of PVA / SrAl2O4:Eu... 2+ ,Dy 3+ All composite materials were successfully composited, with the phosphor crystallinity remaining the best when the ratio of 1PVA:2SAO was used.

[0022] Figure 2 The prepared SrAl2O4:Eu 2+ ,Dy 3+ Scanning electron microscope images of long-afterglow luminescent material samples show SrAl2O4:Eu 2+ ,Dy 3+ The particles are fully encapsulated and bonded by the PVA matrix, exhibiting excellent compatibility and interfacial bonding.

[0023] Figure 3 The prepared SrAl2O4:Eu 2+ ,Dy 3+ The excitation spectrum of the composite material sample is a broadband spectrum at 365 nm.

[0024] Figure 4The prepared SrAl2O4:Eu 2+ ,Dy 3+ The emission spectrum of the composite material sample shows that the sample has the highest emission peak at 520 nm and can emit bright green light under ultraviolet and visible light excitation.

[0025] Figure 5 The prepared SrAl2O4:Eu 2+ ,Dy 3+ The afterglow decay curves of the composite material samples show that the samples have good long afterglow performance.

[0026] Figure 6 This invention synthesizes SrAl2O4:Eu 2+ ,Dy 3+ The tensile strength measurement results of the composite materials prepared at different ratios show that the 1PVA:1SAO ratio exhibits the best overall performance in terms of strength and toughness among all samples.

[0027] Figure 7 This invention synthesizes SrAl2O4:Eu 2+ ,Dy 3+ The temperature-dependent fluorescence emission spectrum of the composite material shows that the SrAl2O4:Eu composite material prepared at 35°C... 2+ ,Dy 3+ Composite materials have the highest emission spectral intensity.

Claims

1. A PVA / SrAl2O4:Eu strain-resistant composite material with excellent strain properties 2+ ,Dy 3+ Composite materials and preparation technology, selecting high-brightness SrAl2O4:Eu 2+ ,Dy 3+ The powder is a luminescent material. Weigh 1-3 grams of PVA, add it to an appropriate amount of warm distilled water, stir at 20-100℃ to obtain a transparent solution, and then add 1-10 grams of SrAl2O4:Eu 2+ ,Dy 3+ The powder is stirred to form a viscous gel, which is then transferred to a mold and dried at 10~60℃ for 1~48 hours to obtain a flexible, semi-transparent composite material.

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