Mechanoluminescent material with high luminous intensity and controllable afterglow and preparation method of mechanoluminescent material

Abstract

The invention provides a mechanoluminescent material with high luminous intensity and controllable afterglow and a preparation method thereof, and belongs to the technical field of functional materials. The preparation method comprises the following steps: mixing aluminum oxide, strontium carbonate, europium oxide, dysprosium oxide, neodymium oxide and boric acid to obtain mixed powder, and calcining the mixed powder to obtain the mechanoluminescent material SrAl2O4: Eu < 2 + >, Dy < 3 + >, Nd < 3 + > (SAOEDN). In the invention, the three rare earth elements of europium, dysprosium and neodymium synergistically regulate the energy level structure of the mechanoluminescent material, the trap depth of the mechanoluminescent material is improved, the mechanoluminescent performance is improved, the doping of the multi-element rare earth elements can realize the on-demand adjustment of the afterglow of the mechanoluminescent material, and the mechanoluminescent material has good application prospects. The prepared mechanoluminescent material with high luminous intensity and controllable afterglow has wide application prospects in the fields of structural health monitoring, biomedicine, flexible sensing devices and the like.

Description

Technical Field

[0001] The invention relates to the technical field of functional materials, and mainly relates to a mechanoluminescent material with high mechanoluminescent intensity and controllable afterglow and a preparation method thereof. Background Art

[0002] Mechanoluminescence (ML) refers to the phenomenon that materials convert mechanical energy into light energy when subjected to mechanical stimulation (such as pressure, impact, etc.), thereby achieving luminescence. Unlike traditional sensing methods, ML materials can autonomously emit light of various wavelengths under the stimulation of mechanical deformation without relying on external energy input. This self-powered luminescence property makes ML materials suitable for monitoring mechanical deformation of two-dimensional and three-dimensional surfaces based on the principle of visual perception. The unique force-light properties of ML materials give them great application potential in structural health monitoring, anti-counterfeiting technology, new light source development, biomedicine and other fields. Strontium oxide-based mechanoluminescent materials (SrAl2O4:Eu 2+ , SrAl2O4:Eu 2+ ,Dy 3+ ) is a typical mechanoluminescent material with good mechanoluminescence effect, which can emit green light under the stimulation of mechanical action. However, the low mechanoluminescence intensity and difficult to control afterglow time of traditional strontium aluminate-based mechanoluminescent materials have significantly restricted their application scope in stress sensing. Therefore, studying how to effectively improve the mechanoluminescence intensity of strontium aluminate-based materials, adjust the afterglow time as needed, and how to better test the mechanoluminescence effect of mechanoluminescent materials have become key issues and challenges faced by the ML research field. Summary of the invention

[0003] In view of this, the present invention provides a mechanoluminescent material (SrAl2O4:Eu 2+ ,Dy 3+ ,Nd 3+ )(SAOEDN) and its preparation method

[0004] In order to achieve the above-mentioned invention object, the present invention provides the following technical solutions:

[0005] The present invention utilizes a multi-element rare earth ion doping strategy to coordinately regulate the trap depth, thereby improving the mechanoluminescence performance and achieving adjustable afterglow.

[0006] In order to achieve the above-mentioned invention object, the present invention provides the following technical solutions:

[0007] The present invention provides a method for preparing a strontium aluminate-based mesoluminescent material with high luminous intensity and controllable afterglow, comprising the following steps:

[0008] 1. Weigh aluminum oxide, strontium carbonate, europium oxide, dysprosium oxide, neodymium oxide and boric acid according to the corresponding molar ratio.

[0009] 2. Using ethanol as a dispersant, magnetic stirring and drying are performed after mixing to obtain a uniformly mixed raw material powder.

[0010] 3. The above powder is calcined at high temperature to obtain SAOEDN material.

[0011] 4. Grind and sieve the material to obtain uniform and fine SAOEDN powder with different particle sizes.

[0012] The europium oxide doping concentration is weighed according to 0.1%, 0.2%, 0.3%, 0.4% and 0.5 mol% of aluminum oxide, the molar ratio of aluminum oxide to europium oxide is 1:0.005-0.025 and the europium oxide concentration is not zero.

[0013] The dysprosium oxide doping concentration is weighed according to 0.1%, 0.2%, 0.3%, 0.4% and 0.5 mol% of aluminum oxide, and the molar ratio of aluminum oxide to dysprosium oxide is 1:0-0.025.

[0014] The doping concentration of neodymium oxide is weighed according to 0.1%, 0.2%, 0.3%, 0.4% and 0.5 mol% of aluminum oxide, and the molar ratio of aluminum oxide to neodymium oxide is 1:0-0.025.

[0015] The calcination temperature is 1000-1600° C., and the calcination time is 3-5 hours.

[0016] The invention provides a strontium aluminate-based mesoluminescent material obtained by the above preparation method.

[0017] The present invention also provides a standard test block for the intensity of mesoluminescence, which is prepared by compounding the above-mentioned mesoluminescent material with a transparent epoxy resin and curing it through a mold, and is used to test the mesoluminescent properties of materials with different doping ratios.

[0018] The present invention provides a mechanoluminescent material (SrAl2O4:Eu 2+ ,Dy 3+ ,Nd 3+ ) comprises the following steps: mixing strontium carbonate, aluminum oxide, europium oxide, dysprosium oxide, neodymium oxide and boric acid to obtain a mixed powder, and calcining the mixed powder at a high temperature to obtain the mechanoluminescent material with high luminous intensity and controllable afterglow. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 SrAl2O4:1%Eu 2+(SAOE) and SrAl2O4:1%Eu 2+ ,1%Dy 3+ ,1%Nd 3+ , XRD pattern of (SAOEDN);

[0020] Figure 2 SrAl2O4:1%Eu 2+ ,1%Dy 3+ ,1%Nd 3+ , excitation spectrum of (SAOEDN);

[0021] Figure 3 ML afterglow time of strontium aluminate based mesoluminescent materials with different doping ratios DETAILED DESCRIPTION

[0022] The present invention provides a mechanoluminescent material with high luminous intensity and controllable afterglow and a preparation method thereof, comprising the following synthesis steps:

[0023] Aluminum oxide, strontium carbonate, europium oxide, dysprosium oxide, neodymium oxide, and boric acid are weighed in corresponding molar ratios and then mixed evenly to obtain a calcined powder precursor;

[0024] calcining the powder precursor at high temperature to obtain the strontium aluminate-based multi-component rare earth doped mesoluminescent powder;

[0025] In the present invention, unless otherwise specified, all raw materials used are commercially available products.

[0026] In the present invention, the rare earth elements include three rare earth elements of europium, dysprosium and neodymium. In particular, the addition of neodymium enables the three elements to better enhance the intensity of electroluminescence and better regulate the afterglow time.

[0027] In the present invention, boric acid is further added to the mixed powder precursor as a flux, which helps to improve the degree of solid solution and crystallinity of each component during the calcination process, thereby improving the mesoluminescent effect of the above-mentioned mesoluminescent material.

[0028] In the present invention, the mixing method of the mixed powder includes wet stirring and dry powder grinding. The wet grinding uses ethanol as a dispersion medium, and after stirring with a magnetic stirrer, the mixture is moved to a ball mill for further ball milling, heated and dried, and the powder is moved to a mortar for grinding to obtain a mixed powder precursor.

[0029] In the present invention, the high-temperature calcination is carried out in a hydrogen furnace, and natural cooling is carried out after the calcination is completed.

[0030] In the present invention, the calcined powder is initially ground manually and then further ground and sieved using an ultrasonic sieving apparatus and sieves of different mesh sizes, so that powders of different particle sizes can be obtained according to needs.

[0031] In the specific embodiment of the present invention, the ratio between the raw materials is calculated according to the stoichiometric ratio of the product.

[0032] In the present invention, the mechanoluminescence afterglow time refers to the time required for the luminescence intensity of the test material to decrease to 10% of the mechanoluminescence peak value.

[0033] The present invention also provides a method for preparing a standard test block for characterizing the mechanoluminescence performance of a material. The mechanoluminescence powder prepared above is mixed with transparent epoxy resin glue in different proportions, and a standard mechanoluminescence intensity performance test block with a certain size can be prepared by molding.

[0034] The epoxy resin described in the present invention is a commercially available highly transparent epoxy resin, the main components of which are epoxy resin, transparent defoamer and the like.

[0035] The following is a clear and complete description of the technical solution of a high-luminous intensity and controllable afterglow mechanoluminescent material and a preparation method thereof described in the present invention in combination with examples. The described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Example 1

[0037] Preparation of three rare earth element doped strontium aluminate based mesoluminescent materials SrAl2O4:1%Eu by high temperature solid phase reaction 2+ ,1%Dy 3+ ,1%Nd 3+ ,(SAOEDN), includes the following steps:

[0038] Step 1: Weigh 0.1 mol Al2O3, 0.1 mol SrCO3, 0.0005 mol Eu2O3, 0.0005 mol Dy2O3, 0.0005 mol Nd2O3, and 0.01 mol H3BO3 according to the chemical atomic stoichiometric ratio, mix the raw materials, put them into a beaker, add a magnetic rotor and an appropriate amount of ethanol, and stir on a magnetic stirrer for 2 hours.

[0039] Step 2: Transfer the mixture obtained in step 1 to a zirconia ball mill. The ball mill beads in the ball mill are arranged in a mass ratio of 1:1 to the mixture. The ball mill beads are graded according to the principle of equal surface area. The fully ground suspension is placed in a drying oven to dry ethanol to obtain a uniformly dispersed precursor powder, and the precursor powder is transferred to a corundum crucible.

[0040] Step 3: Transfer the precursor powder to a hydrogen furnace and calcine the sample at 1400°C for 4 h in a mixed reducing atmosphere of 95% nitrogen and 5% hydrogen.

[0041] Step 4: Cool naturally, use ethanol as a dispersant for the calcined powder, ball-mill it again, and then dry it to remove the ethanol. Then, use an ultrasonic vibration sieving instrument to sieve the powder to obtain SAOEDN mechanoluminescent powder of different particle sizes.

[0042] The raw materials in step 1 are mixed with europium oxide and sintered in the same way to obtain SrAl2O4:Eu 2+ (SAOE), SAOE and SAOEDN were subjected to XRD test, and the obtained spectrum was compared with the standard card. Figure 1 The results show that the doping of rare earth elements does not change the structure of the strontium aluminate crystal itself, nor does it introduce impurities into the crystal, confirming the successful doping of rare earth elements. Figure 2 As shown, the results show that the material has a high luminescence intensity under ultraviolet light excitation in the wavelength range of 320nm-370nm, and the excitation wavelength corresponding to its peak intensity is 365nm. Therefore, ultraviolet light with a wavelength of 365nm is selected in the subsequent material excitation and charging to facilitate testing.

[0043] Example 2

[0044] Preparation of mechanoluminescent materials with different rare earth element doping ratios by high temperature solid phase reaction method, SrAl2O4:2%Eu 2+ ,3%Dy 3+ ,1%Nd 3+ For example, the following steps are included:

[0045] Step 1: Weigh 0.1 mol Al2O3, 0.1 mol SrCO3, 0.001 mol Eu2O3, 0.0015 mol Dy2O3, 0.0005 mol Nd2O3 and 0.01 mol H3BO3 respectively according to the chemical atomic stoichiometric ratio, put the raw materials into a beaker, add a magnetic rotor and an appropriate amount of ethanol, stir on a magnetic stirrer for 2 h to obtain a raw material mixture.

[0046] Step 2: Transfer the mixture to a zirconia ball mill. The ball mill beads in the ball mill are set at a mass ratio of 1:1 to the powder sample. The ball mill beads are graded according to the principle of equal surface area. The fully ground suspension is placed in a drying oven to dry the ethanol to obtain a uniformly dispersed precursor powder, and the precursor powder is transferred to a corundum crucible.

[0047] Step 3: Transfer the raw material powder to a hydrogen furnace and calcine the sample at 1400°C for 4 hours in a mixed reducing atmosphere of 95% nitrogen and 5% hydrogen.

[0048] Step 4: Cool naturally, use ethanol as a dispersant to ball-mill the calcined powder again, and then dry it to remove the ethanol. Then, use an ultrasonic vibration sieving instrument to sieve the powder to obtain different rare earth element-doped luminescent powders of different particle sizes.

[0049] The performance of mechanoluminescence and mechanoluminescence afterglow of SAOEDN materials with various doping ratios was tested. The results are shown in the attached figure. Figure 3 As shown in the figure, it can be seen that the mechanoluminescence intensity of SAOEDN material is greatly improved on the basis of Eu element doping, which is two orders of magnitude higher than that of SAOE, proving that the doping of Dy and Nd elements effectively improves the mechanoluminescence effect of SAOE. Figure 3 At the same time, the ML afterglow test results of the materials prepared by changing the doping ratios of different rare earth elements are shown. It can be seen from the ML afterglow time results that the ML afterglow time of SAOE is extremely short, while the ML afterglow time of SAOEDN material doped with three elements can be adjusted from 50s to 325s by changing the doping ratios of different rare earth elements, demonstrating the adjustable afterglow performance of the material.

Claims

1. A mesoluminescent material with high mesoluminescent intensity and controllable afterglow and a preparation method thereof, characterized in that: The following steps are involved: Aluminum oxide, strontium carbonate, europium oxide, dysprosium oxide, neodymium oxide and boric acid are weighed according to corresponding molar ratios and dispersed to obtain uniformly mixed raw material powders; the powders are calcined at high temperature to obtain the mechanoluminescent material.

2. The preparation method according to claim 1, characterized in that: The rare earth elements include europium, dysprosium and neodymium.

3. The preparation method according to claim 1 or 2, characterized in that: The molar ratio of aluminum oxide to europium oxide is 1:0.005-0.025 and the concentration of europium oxide is not zero.

4. The preparation method according to claim 1 or 2, characterized in that: The molar ratio of aluminum oxide to dysprosium oxide is 1:0 to 0.

025.

5. The preparation method according to claim 1 or 2, characterized in that: The molar ratio of aluminum oxide to neodymium oxide is 1:0 to 0.

025.

6. The preparation method according to claim 1 or 2, characterized in that: Boric acid is also added during the mixing, and the molar ratio of aluminum oxide to boric acid is 1:0 to 0.

15.

7. The preparation method according to claim 1 or 2, characterized in that: The calcination temperature is 1000-1600° C., and the calcination time is 3-5 hours.

8. The mechanoluminescent material obtained by the preparation method according to any one of claims 1 to 7.

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