Technology for enhancing luminous intensity and water resistance of CaAl2O4: Eu < 2 + >, Nd < 3 + > blue long-afterglow phosphorescent material

Abstract

The invention discloses a technology for enhancing luminous intensity and water resistance of a CaAl2O4: Eu < 2 + >, Nd < 3 + > blue long-afterglow phosphorescent material, which is characterized in that CO (NH2) 2 is used as a fuel, NH4B5O8 is used as a reducing agent and a reactant, and a CaAl2B2O7 long-afterglow material sample with good luminous property and excellent water resistance is synthesized by a one-step combustion method. The CaAl2O4: Eu < 2 + >, Dy < 3 + > long-afterglow material treated by the method has ultrahigh brightness and excellent water resistance, the luminous intensity is only reduced by 17% after the material is soaked in water for 7 days, the operation is simple, and the method is suitable for industrial scale production.

Description

Technical Field

[0001] The present invention relates to a kind of enhanced CaAl2O4:Eu 2+ ,Nd 3+ The invention relates to a technology for improving the luminous intensity and water resistance of long afterglow phosphorescent materials. The technology can enhance the water resistance and photoluminescence intensity of blue long afterglow luminescent materials and belongs to the field of optoelectronic functional materials. Background Art

[0002] Long afterglow material is a new type of phosphorescent material that can convert absorbed ultraviolet or visible light into visible light and can continue to emit light for a long time after the excitation stops. Among the blue long afterglow materials that have been put into commercial use, CaAl2O4:Eu 2+ ,Nd 3+ Long afterglow phosphorescent materials have attracted much attention. It is reported that CaAl2O4:Eu 2+ ,Nd 3+ The luminous intensity of long afterglow phosphorescent materials is low, the afterglow time is short, and because of its alkaline earth aluminate structure, its water resistance is very poor. After contact with water, it will quickly undergo hydrolysis reaction, causing structural damage, which greatly affects the luminescence and afterglow performance of long afterglow materials.

[0003] Currently, researchers are working on CaAl2O4:Eu 2+ ,Nd 3+ The treatment of water resistance of long afterglow phosphorescent materials usually focuses on coating, that is, introducing a layer of organic or inorganic film on the surface of the material to isolate water molecules and reduce the water sensitivity of the material. However, this coating usually reduces the luminescence performance of the long afterglow material, and it will come into contact with water during the coating process, causing unnecessary losses. In 2000, Zhang Ming et al. used methyl silicone oil to treat CaAl2O4:Eu 2+ ,Nd 3+ The long afterglow phosphorescent material was surface treated and then coated with SiO2 on the surface of the luminescent material. Although the water resistance of the powder was improved, its luminescent performance was greatly reduced. In 2000, Zhu Zhongli et al. coated aluminum silicate and aluminum phosphate on the surface of aluminate luminescent materials to improve their water resistance, but the operation method was too complicated and not suitable for large-scale industrial production. In 2005, Sun Zhongxin et al. used the sol-gel method to produce CaAl2O4:Eu 2+ ,Nd 3+ The surface of the long afterglow phosphorescent material is coated with a layer of SiO2. A series of detection methods such as XRD and SEM prove that the coating of amorphous SiO2 is successful. 2+ ,Nd 3+ The long afterglow phosphorescent material is water resistant, but the luminous intensity of the coated material is reduced by 28.9% compared with that before treatment.

[0004] To this end, the present invention develops a simple CaAl2O 4: Eu 2+ ,Nd 3+ Long afterglow material coating technology improves the water resistance of powder and enhances the luminescence intensity of powder, which is conducive to promoting the development of CaAl2O4:Eu 2+ ,Nd 3+ The application of long afterglow materials is of great significance. Summary of the invention

[0005] In order to improve the blue CaAl2O4:Eu 2+ ,Nd 3+ The present invention proposes a method for enhancing the water resistance and luminescence performance of long afterglow materials. 2+ ,Nd 3+ Technology for improving the luminous intensity and water resistance of long-lasting phosphorescent materials.

[0006] The present invention uses CaAl2O4:Eu 2+ ,Nd 3+ Based on long afterglow materials, NH4B5O8 is used as a reducing agent and reaction raw material, CO(NH2)2 is used as a fuel, and CaAl2O4:Eu is made by combustion method. 2+ ,Nd 3+ The surface reacts with NH4B5O8 to produce a continuous and dense amorphous CaAl2B2O7 layer, which improves the water resistance of the powder. At the same time, a large amount of reducing atmosphere is generated to make the residual unreduced Eu 3+ Reduction to Eu 2+ The ultra-high temperature generated by combustion makes CaAl2O4:Eu 2+ ,Dy 3+ The crystallinity is further improved, which enhances the luminescence intensity of the powder. 2+ ,Nd 3+ , CO(NH2)2, NH4B5O8 as raw materials, CO(NH2)2 as fuel, NH4B5O8 as reducing agent and reactant, fuel CO(NH2)2 and CaAl2O4:Eu 2+ ,Nd 3+ The ratio of the theoretical amount is 1 to 3:1. The amount of NH4B5O8 is NH4B5O8 and CaAl2O4:Eu 2+ ,Nd 3+ The mass ratio is 0.5-1.5:1. The CaAl2O4:Eu with good luminescence performance and excellent water resistance can be obtained by reacting at an ignition temperature of 400-600℃ for 5-25min. 2+ ,Nd 3+ Long afterglow material sample. The method of the invention is simple and efficient, which not only improves the water resistance of the powder, but also greatly enhances the luminescence performance of the powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 The CaAl2O4:Eu 2+ ,Nd 3+ XRD patterns of long afterglow materials before and after treatment.

[0008] Figure 2 The ammonium pentaborate treated CaAl2O4:Eu 2+ ,Nd 3+ Scanning electron microscope image of long afterglow material.

[0009] Figure 3 It is CaAl2O4:Eu before and after treatment in the present invention 2+ ,Nd 3+ Excitation spectrum of long afterglow materials.

[0010] Figure 4 It is CaAl2O4:Eu before and after treatment in the present invention 2+ ,Nd 3+ Emission spectra of long afterglow materials.

[0011] Figure 5 It is CaAl2O4:Eu before and after treatment in the present invention 2+ ,Nd 3+ Afterglow decay curve of long afterglow material.

[0012] Figure 6 The ammonium pentaborate treated CaAl2O4:Eu 2+ ,Nd 3+ Comparison of excitation spectra of long afterglow materials in water for 7 days.

[0013] Figure 7 The ammonium pentaborate treated CaAl2O4:Eu 2+ ,Nd 3+ Comparison of emission spectra of long afterglow materials in water for 7 days.

[0014] Figure 8 The ammonium pentaborate treated CaAl2O4:Eu 2+ ,Nd 3+ Comparison of excitation spectra of long afterglow material and untreated material in water for 7 days.

[0015] Fig. 9 The ammonium pentaborate treated CaAl2O4:Eu 2+ ,Nd 3+ Comparison of emission spectra of long afterglow material and untreated material in water for 7 days. DETAILED DESCRIPTION

[0016] The present invention synthesizes CaAl2O4:Eu 2+ ,Nd 3+ The specific process of long afterglow powder with excellent luminescence performance and water resistance is described as follows:

[0017] (1) CaAl2O4:Eu 2+ ,Nd 3+ , NH4B5O8, CO(NH2)2 as raw materials, according to NH4B5O8 and CaAl2O4:Eu 2+ ,Nd 3+ Mass ratio 0.5:1, CO(NH2)2 and CaAl2O4:Eu 2+ ,Nd 3+ The ratio is 1:1 of the theoretical dosage.

[0018] (2) According to the preparation of 5g sample, the corresponding amount of CaAl2O4:Eu was weighed using a precision electronic balance. 2+ ,Nd 3+ , NH4B5O8, CO(NH2)2 raw materials, put the weighed raw materials into an agate mortar, grind for 20 minutes to mix the raw materials evenly, and put them into a 300ml crucible.

[0019] (3) Place the 300 ml crucible containing the raw materials into a muffle furnace preheated to 400-600°C and react for 15 minutes.

[0020] (4) After sintering, the furnace is cooled, and the sample is washed with alcohol, centrifuged, and dried to obtain CaAl2O4:Eu with good luminescence performance and excellent water resistance. 2+ ,Nd 3+ @CaAl2B2O7 long afterglow material sample.

[0021] Figure 1 CaAl2O4:Eu prepared after washing and drying with ethanol 2+ ,Nd 3+ From the XRD diagrams of the long afterglow material before and after treatment, it can be seen that no other impurities appear after the combustion treatment. It is judged that the generated CaAl2B2O7 is amorphous and the crystallinity of CaAl2O4 improves.

[0022] Figure 2 The prepared CaAl2O4:Eu treated with ammonium pentaborate 2+ ,Nd 3+ From the scanning electron microscope image of the long afterglow material, it can be seen that the particle size of the sample prepared by the present invention is between 3 and 4 μm, with good dispersibility and fine particle size.

[0023] Figure 3The prepared CaAl2O4:Eu 2+ ,Nd 3+ The excitation spectrum of the long afterglow material shows a broadband spectrum of 348 nm. Compared with before treatment, the excitation spectrum of the powder after combustion treatment with ammonium pentaborate has been significantly improved.

[0024] Figure 4 The prepared CaAl2O4:Eu 2+ ,Nd 3+ The emission spectrum of the long afterglow material shows that the sample has the highest emission peak at 440nm. Compared with before treatment, the emission spectrum of the powder after combustion treatment with ammonium pentaborate has been significantly improved.

[0025] Figure 5 The prepared CaAl2O4:Eu 2+ ,Nd 3+ The afterglow attenuation curve of the long afterglow material shows that the afterglow attenuation of the treated powder is better than that of the untreated powder, and has good afterglow performance.

[0026] Figure 6 The prepared CaAl2O4:Eu treated with ammonium pentaborate 2+ ,Nd 3+ Comparison of the excitation spectra of long afterglow materials in water for 7 days. It can be seen that after 7 days of soaking in water, the excitation spectrum of the powder has not changed much.

[0027] Figure 7 The prepared CaAl2O4:Eu treated with ammonium pentaborate 2+ ,Nd 3+ Comparison of emission spectra of long afterglow materials in water for 7 days. It can be seen that after 7 days of soaking in water, the emission spectrum of the powder has not changed much, and the luminous intensity has only decreased by 17%.

[0028] Figure 8 The prepared CaAl2O4:Eu treated with ammonium pentaborate 2+ ,Nd 3+ Comparison of the excitation spectra of the long afterglow material and the untreated material in water for 7 days. It can be seen that the untreated powder has almost no excitation spectrum.

[0029] Fig. 9 The prepared CaAl2O4:Eu treated with ammonium pentaborate 2+ ,Nd 3+ Comparison of emission spectra of long afterglow material and untreated material in water for 7 days. It can be seen that the untreated powder hardly emits light after being soaked in water for 7 days.

Claims

1. An enhanced CaAl2O4:Eu 2+ ,Nd 3+ The technology of improving the luminous intensity and water resistance of long afterglow phosphorescent materials is based on CaAl2O4:Eu 2+ ,Nd 3+ , CO(NH2)2, NH4B5O8 as raw materials, CO(NH2)2 as fuel, NH4B5O8 as reducing agent and reactant, fuel CO(NH2)2 and CaAl2O4:Eu 2+ ,Nd 3+ The ratio of NH4B5O8 to CaAl2O4:Eu is 1 to 3:1 in theoretical dosage. 2+ ,Nd 3+ The mass ratio is 0.5-1.5:

1. The CaAl2O4:Eu with good luminescence performance and excellent water resistance can be obtained by reacting at an ignition temperature of 400-600℃ for 5-25min. 2+ ,Nd 3+ Long afterglow material samples.

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