Multicolor self-recovery mechanoluminescent material, and preparation method and application thereof

Abstract

The invention provides a multicolor self-recovery mechanoluminescent material as well as a preparation method and application thereof. The chemical general formula of the multicolor self-recovery mechanoluminescent material is LiGa (1-x) MxO2, wherein M is any one of Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Nd, Fe, Mn or Cr, and x < lt > is greater than or equal to 0.001; 1; x represents the molar percentage content. According to the invention, by doping different rare earth or transition metal elements in LiGaO2, full-spectrum mechanoluminescence can be realized, the luminescence of the material can be self-recovered without pre-charging, and the material has a good application prospect in the fields of stress sensors, flexible display equipment, crack monitoring, biological imaging, encryption systems and the like. The self-recovery mechanoluminescent material system is broadened, and the mechanoluminescent material is fired in one step by adopting a high-temperature solid-phase reaction method, has the advantages of low cost and simple preparation conditions, and is convenient for mass production.

Description

Technical Field

[0001] The invention relates to the field of luminescent materials, in particular to a multicolor self-recovering mechanoluminescent material, a preparation method and application thereof. Background Art

[0002] Luminescence is the process of releasing energy in the form of light after an object absorbs external energy. Luminescence can be stimulated by many ways, such as photoluminescence, which is caused by the use of light to stimulate the object, electroluminescence, which is the conversion of electrical energy into light energy, chemiluminescence caused by the breaking of chemical bonds, and thermoluminescence caused by the increase in temperature. In addition to the above forms of luminescence, some materials will also emit fluorescence when subjected to external mechanical stimulation (such as friction, compression, grinding and stretching, etc.), which is called mechanoluminescence. Mechanoluminescence is the process of directly converting the mechanical energy received by an object into light energy. It is a rare new type of luminescence. In recent years, with the improvement of the luminescence intensity of such materials, the exploration and reporting of new materials, and the advancement of new detection technologies, the research on mechanoluminescent materials is gradually becoming a research hotspot and has made phased progress. A large number of experiments have also successfully confirmed the high feasibility of using mechanoluminescent materials for a series of advanced applications such as crack detection, pressure sensing, and stress visualization sensing. In particular, mechanoluminescent materials can use mechanical energy commonly found in daily life to excite materials, which can avoid the requirement that traditional materials must use specific excitation sources. They have the advantages of green energy saving and real-time response, so they have potential application value in visual imaging, new light sources and displays, crack monitoring, and anti-counterfeiting encryption of information. However, the current mechanoluminescent material system is quite limited, especially the self-recovering mechanoluminescent materials that do not require pre-charging, mainly sulfides and sulfur oxides. Therefore, there is an urgent need for new self-recovering mechanoluminescent materials with higher efficiency and adjustable luminescent color. Summary of the invention

[0003] The purpose of the present invention is to provide a multicolor self-recovering mechanoluminescent material, a preparation method and application thereof. The multicolor self-recovering mechanoluminescent material is a LiGaO 2 Doping with transition metals or rare earth ions can achieve multicolor emission from the visible to near-infrared bands, opening up new opportunities for LiGaO-based 2 New myristic luminescent materials for the system.

[0004] The present invention is achieved in that:

[0005] The chemical formula of the multicolor self-recovering mechanoluminescent material provided by the present invention is: LiGa 1-x M x O 2; wherein M is a combination of any one or more of Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Nd, Fe, Mn or Cr, 0.001≤x<1; x represents the molar percentage content.

[0006] In the present invention, due to Ga 3+ Ions have similar radii to a variety of rare earth ions and transition metal ions and can be found in LiGaO 2 Different transition metals or rare earth ions are doped in the nanostructured carbon nanotubes. Under the stimulation of mechanical force, they exhibit multicolor mechanoluminescence in the visible to near-infrared bands, and do not require ultraviolet light pre-irradiation. They are self-recovering mechanoluminescent materials. This mechanoluminescent material has good application prospects in stress sensors, flexible display devices, crack monitoring, biological imaging and encryption systems.

[0007] The preparation method of the above multicolor self-recovering mechanoluminescent material is as follows:

[0008] a. According to the chemical formula LiGa 1-x M x O 2 In the stoichiometric ratio of each element, lithium carbonate (10% excess), gallium oxide and oxide or carbonate of element M are weighed; the oxide or carbonate of element M refers to: when M is Mn, manganese carbonate is selected; when M is an element other than Mn, the oxide of M is selected;

[0009] b. Place the raw materials weighed in step a in an agate mortar, add anhydrous ethanol to mix thoroughly, grind into powder, and place in a crucible;

[0010] c. Place the crucible in step b into a protective atmosphere of 10% H 2 -90% N 2 Calcine in a high temperature tube furnace at 1300°C for hours;

[0011] d. After cooling naturally to room temperature, take it out and grind it into powder in a mortar to obtain LiGa 1-x M x O 2 Physioluminescent materials.

[0012] The present invention provides a self-recovering LiGaO that can be doped with different rare earth and transition metal elements to achieve full-spectrum mechanoluminescence 2 The preparation method of the system broadens the mechanoluminescent material system. The high temperature solid phase reaction adopted by the present invention has the advantages of low cost, simple preparation conditions, etc., and is convenient for mass production.

[0013] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0014] (1) LiGaO in the present invention 2 The mechanoluminescent material system is prepared by a traditional solid-phase reaction method, which has a simple process, low equipment requirements, easy control of conditions, and low cost. Compared with typical mechanoluminescent materials such as sulfides and sulfur oxides, the mechanoluminescent material provided by the present invention does not produce toxic and harmful substances during the preparation process and is environmentally friendly.

[0015] (2) By doping transition metals or rare earth ions as luminescence centers, full-spectrum multi-color high-efficiency induced luminescence can be achieved, which has potential application value in sensing fields such as stress visualization distribution, temperature and pressure recording, and construction or mechanical engineering structure diagnosis.

[0016] (3) The mechanoluminescence provided by the present invention is self-recovering and does not require pre-irradiation charging or other treatments, thus expanding the application scenarios of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the powder X-ray diffraction pattern of the samples with the ratios (1) to (5) of Example 1.

[0018] Figure 2 This is the mesoluminescence spectrum of the samples with the ratios (1)-(5) of Example 1.

[0019] Figure 3 It is the integrated intensity of the mesoluminescence of the sample with the ratio (2) in Example 1 under 15 times of mechanical force.

[0020] Figure 4 This is the powder X-ray diffraction spectrum of the samples with the ratios (1) to (6) of Example 2.

[0021] Figure 5 This is the mesoluminescence spectrum of the samples with the ratios (1)-(6) of Example 2. DETAILED DESCRIPTION

[0022] The following are some specific LiGaO doped with different ions 2 The preparation method of the mechanoluminescent material is provided to further explain the technical solution of the present invention.

[0023] Example 1

[0024] This example is a high temperature solid phase method for preparing LiGa 1-x O 2 :xMn 2+ The specific preparation process of the mechanoluminescent material is as follows:

[0025] First, select the raw materials. Lithium carbonate is selected as the Li element; gallium oxide (analytical grade) is selected as the Ga element; and manganese carbonate (analytical grade) is selected as the Mn element. Since lithium carbonate will volatilize during the calcination process, lithium carbonate is added in excess of 10%. Lithium carbonate, gallium oxide, and manganese carbonate compound raw materials are weighed according to the molar ratio of each element, a total of 5 groups, with the following ratios:

[0026] (1)Li + :Ga 3+ :Mn 2+ =1.1:0.999:0.001, corresponding to x=0.1%, weigh Li in molar ratio 2 CO 3 0.2845g, Ga 2 O 3 (AR)0.6554g, MnCO 3 (AR) 0.0008g;

[0027] (2)Li + :Ga 3+ :Mn 2+ =1.1:0.995:0.005, corresponding to x=0.5%, weigh Li in molar ratio 2 CO 3 0.2845g, Ga 2 O 3 (AR)0.6528g, MnCO 3 (AR) 0.0040g;

[0028] (3)Li + :Ga 3+ :Mn 2+ =1.1:0.99:0.01, corresponding to x=1%, weigh Li in molar ratio 2 CO 3 0.2845g, Ga 2 O 3 (AR)0.6495g, MnCO 3 (AR) 0.0080g;

[0029] (4)Li + :Ga 3+ :Mn 2+ =1.1:0.97:0.03, corresponding to x=3%, weigh Li in molar ratio 2 CO 3 0.2845g, Ga 2 O 3 (AR)0.6364g, MnCO 3 (AR) 0.0241g;

[0030] (5)Li+ :Ga 3+ :Mn 2+ =1.1:0.95:0.05, corresponding to x=5%, weigh Li in molar ratio 2 CO 3 0.2845g, Ga 2 O 3 (AR)0.6232g, MnCO 3 (AR) 0.0401g;

[0031] The weighed raw materials were placed in an agate mortar, and an appropriate amount of anhydrous ethanol was added to mix them thoroughly. The raw materials were fully ground into powder, and then placed in a crucible and placed in a protective atmosphere of 10% H 2 -90% N 2 It is calcined at 1300℃ for 6 hours in a high-temperature tube furnace, cooled to room temperature naturally, taken out, and ground into powder in a mortar. 1- x O 2 :xMn 2+ Phosphorescent materials.

[0032] The samples formed by the five different ratios in Example 1 were subjected to X-ray diffraction tests, and the results obtained are as follows: Figure 1 shown. Figure 1 The mid-range line was measured using a Bruker D8 Advance X-ray diffractometer with a test voltage of 40 kV, a current of 40 mA, and a Cu target. As the radiation source, the scanning range is 20°-70° with a step size of 0.02°. Figure 1 It can be seen that with the increase of Mn 2+ With the increase of content (x value), the X-ray diffraction peak of the sample did not change significantly, proving that all samples are single pure phase LiGaO 2 , and Mn 2+ Doping has little effect on the structural crystal phase.

[0033] Figure 2 The mechanoluminescence spectra of the samples with the ratios (1) to (5) of Example 1 were measured by an Ocean Optics QEPro fiber optic spectrometer from the United States. The data acquisition integration time was 2 seconds, the scanning step was 1 nm, and the excitation method was friction force, the magnitude was set to 50 N, and the action time was 2 seconds. Figure 2 It can be seen that under the action of mechanical force, the material produces a red luminescence band with a peak value of about 650nm, corresponding to Mn 2+ Ionic 4 T 1 → 6 A 1 Transition.

[0034] Figure 3 The integral intensity of the mechanoluminescence of the sample of the ratio (2) of Example 1 under 15 mechanical forces was measured using the American Ocean Optics QEPro fiber optic spectrometer, with an integration time of 2 seconds and a scanning step of 1 nm; the excitation mode was friction, the magnitude was set to 50N, the action time was 2s, and the force was applied once to obtain a spectrum; before the test, the sample was heated at 300 degrees Celsius for 20 minutes to drain the energy stored in the trap. Figure 3 As shown in the figure, the material has little loss of mesoluminescence intensity after 15 cycles of mechanical force stimulation, which shows the characteristics of self-recovery mesoluminescence. This also verifies that LiGaO 2 The matrix material has self-healing properties.

[0035] Example 2

[0036] This example is a high temperature solid phase method for preparing LiGa 0.99 O 2 :0.01M 3+ The mechanoluminescent material, wherein M is Eu, Tb, Sm, Dy, Tm, Fe, has the following specific preparation process:

[0037] First, select the raw materials. For Li, select lithium carbonate; for Ga, select gallium oxide (analytical grade); for M, select oxide (analytical grade). Since lithium carbonate will volatilize during the calcination process, lithium carbonate is added in excess of 10%. + :Ga 3+ :M 3+ = Lithium carbonate, gallium oxide and M oxide were weighed in a stoichiometric ratio of 1.1:0.99:0.01. The M oxides were europium oxide, terbium oxide, samarium oxide, dysprosium oxide, thulium oxide and iron oxide, a total of 6 groups, with the following proportions:

[0038] (1)Li + :Ga 3+ :M 3+ =1.1:0.99:0.01, weigh Li in molar ratio 2 CO 3 0.2845g, Ga 2 O 3 (AR) 0.6495g, Eu 2 O 3 (AR) 0.0123g;

[0039] (2)Li + :Ga 3+ :M 3+ =1.1:0.99:0.01, weigh Li in molar ratio 2 CO 30.2845g, Ga 2 O 3 (AR)0.6495g, Tb 4 O 7 (AR) 0.0131g;

[0040] (3)Li + :Ga 3+ :M 3+ =1.1:0.99:0.01, weigh Li in molar ratio 2 CO 3 0.2845g, Ga 2 O 3 (AR)0.6495g, Sm 2 O 3 (AR) 0.0122g;

[0041] (4)Li + :Ga 3+ :M 3+ =1.1:0.99:0.01, weigh Li in molar ratio 2 CO 3 0.2845g, Ga 2 O 3 (AR)0.6495g, Dy 2 O 3 (AR) 0.0131g;

[0042] (5)Li + :Ga 3+ :M 3+ =1.1:0.99:0.01, weigh Li in molar ratio 2 CO 3 0.2845g, Ga 2 O 3 (AR)0.6495g, Tm 2 O 3 (AR) 0.0135g;

[0043] (6)Li + :Ga 3+ :M 3+ =1.1:0.99:0.01, weigh Li in molar ratio 2 CO 3 0.2845g, Ga 2 O 3 (AR)0.6495g,Fe 2 O 3 (AR) 0.0056g;

[0044] The weighed raw materials were placed in an agate mortar, and an appropriate amount of anhydrous ethanol was added to mix them thoroughly. The raw materials were fully ground into powder, and then placed in a crucible and placed in a protective atmosphere of 10% H 2 -90% N 2 It is calcined at 1300℃ for 6 hours in a high-temperature tube furnace, cooled to room temperature naturally, taken out, and ground into powder in a mortar. 0.99 O 2 :0.01M 3+ Mechanoluminescent material, wherein M is Eu, Tb, Sm, Dy, Tm, Fe.

[0045] The samples formed by the ratios (1) to (6) in Example 2 were subjected to X-ray diffraction tests, and the results obtained are as follows: Figure 4 shown. Figure 4 The mid-range line was measured using a Bruker D8 Advance X-ray diffractometer with a test voltage of 40 kV, a current of 40 mA, and a Cu target. As the radiation source, the scanning range is 20°-70° with a step size of 0.02°. Figure 4 It can be seen that after doping with different ions, the X-ray diffraction peaks of the samples did not change significantly, proving that all samples are single pure phase LiGaO 2 , and doping has little effect on the structural crystal phase.

[0046] Figure 5 The mechanoluminescence spectra of the samples with the ratios (1) to (6) of Example 2 were measured by an Ocean Optics QEPro fiber optic spectrometer in the United States. The data acquisition integration time was 2 seconds, the scanning step was 1 nm, and the excitation method was friction force, the magnitude was set to 50 N, and the action time was 2 seconds. Figure 5 It can be seen that under the action of mechanical force, the material can emit emission bands originating from characteristic transitions of different ions, and its emission band covers visible to near-infrared.

Claims

1. A multicolor self-recovering mechanoluminescent material, characterized in that: The general chemical formula is LiGa 1-x M x O2; wherein M is any one of Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Nd, Fe, Mn or Cr, 0.001≤x<1.

2. The multicolor self-recovering mechanoluminescent material according to claim 1, characterized in that: The value of x is 0.001≤x≤0.

05.

3. The multicolor self-recovering mechanoluminescent material according to claim 1, characterized in that: M is Mn, Eu, Tb, Sm, Dy, Tm or Fe.

4. A method for preparing the multicolor self-recovering mechanoluminescent material according to claim 1, characterized in that: The steps include: a. According to the chemical formula LiGa 1-x M x Weigh 10% excess lithium carbonate, gallium oxide and oxide or carbonate of M in the stoichiometric ratio of each element in O2. The oxide or carbonate of M refers to: when M is Mn, manganese carbonate is selected; when M is an element other than Mn, the oxide of M is selected; b. Place the raw materials weighed in step a in an agate mortar, add anhydrous ethanol to mix thoroughly, grind into powder, and place in a crucible; c. Place the crucible in step b into a high temperature tube furnace and calcine at 1300° C. for 6 hours; d. After cooling naturally to room temperature, take it out and grind it into powder in a mortar to obtain LiGa 1-x M x O2 mesoluminescent material.

5. The method for preparing a multicolor self-recovering mechanoluminescent material according to claim 4, characterized in that the steps In c, a protective atmosphere of 10% H2-90% N2 is introduced into the high temperature tube furnace.

6. Application of the multicolor self-recovering mechanoluminescent material described in any one of claims 1 to 3 and the multicolor self-recovering mechanoluminescent material prepared by the method described in any one of claims 4 to 5 in stress sensors, flexible display devices, crack monitoring, bio-imaging or encryption systems.

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