Near-infrared stress fluorescent powder and preparation method thereof

Abstract

The invention provides near-infrared stress fluorescent powder and a preparation method thereof. The general chemical formula of the near-infrared stress fluorescent powder is MgGa2-xCrxO4, wherein x is more than 0 and less than or equal to 0.05. The preparation method of the near-infrared stress fluorescent powder comprises the following steps: a, weighing oxides containing Mg, Ga and Cr elements according to the molar ratio of each element in the general chemical formula MgGa2-xCrxO4 of the fluorescent powder, mixing and grinding to obtain a mixture; b, heating the mixture to 500 DEG C, roasting for 0.5 h, continuously heating to 1300 DEG C, roasting for 6 h, and cooling to room temperature to obtain a sintered body; and c, fully grinding the obtained sintered body to obtain the near-infrared stress fluorescent powder. The novel near-infrared stress fluorescent powder provided by the invention is simple in preparation process, easy to operate and control, high in safety, short in preparation time, high in production efficiency and suitable for industrial large-scale production, popularization and application, and the production cost is greatly reduced compared with the prior art.

Description

Technical Field

[0001] The invention relates to the field of stress luminescent materials, in particular to a near-infrared stress fluorescent powder and a preparation method thereof. Background Art

[0002] The near-infrared region is a non-visible light region that was discovered earlier. Due to the low level of early technology, the spectrum overlapped and the analysis was complicated due to the influence of frequency doubling and frequency combination, which limited the research and application of near-infrared light. It was not until the 1960s that the emergence of commercial instruments and the extensive work done by Norris et al. proposed the theory that the content of a substance is linearly related to the absorption peaks of multiple different wavelengths in the near-infrared region, and used NIR diffuse reflectance technology to determine the moisture, protein, fat and other components in agricultural products, which made near-infrared spectroscopy technology widely used in the analysis of agricultural and sideline products. In the mid-to-late 1960s, with the emergence of various new analytical techniques, coupled with the weaknesses of low sensitivity and poor anti-interference of classical near-infrared spectroscopy analysis technology, people became indifferent to the application of this technology in analytical testing. Since then, near-infrared spectroscopy has entered a period of silence.

[0003] The successful application of multivariate correction technology in spectral analysis, an important part of the chemometrics discipline that emerged in the 1970s, promoted the promotion of near-infrared spectroscopy technology. In the late 1980s, with the rapid development of computer technology, the digitization of analytical instruments and the development of chemometrics were driven. The good results achieved by chemometric methods in solving spectral information extraction and background interference, coupled with the unique characteristics of near-infrared spectroscopy in sample measurement technology, made people re-recognize the value of near-infrared spectroscopy, and the application research of near-infrared spectroscopy in various fields was launched one after another.

[0004] With the further development of near-infrared technology, near-infrared has been extended to many medical fields, such as pharmacology, molecular cell biology and diagnostics. Hospitals in the United States are trying to use a new instrument to help nurses find blood vessels on patients' arms. The principle is to detect the location of blood vessels with the help of near-infrared rays that are harmless to the human body, and project the distribution image of blood vessels onto the arm in real time, so that medical staff know where to insert the needle, which may save them from the pain of "wrongful needles". Near-infrared fluorescent markers emit light in the near-infrared region, where biological molecules do not emit light and there is no spectral overlap interference. Near-infrared fluorescent markers can be excited by visible light of shorter wavelengths, thereby avoiding the dispersion of excitation light and obtaining higher sensitivity. In addition, near-infrared light has a large penetration depth in living biological tissues, can generate light signals in deep tissues, and has almost no effect on the tissues themselves, so it is conducive to obtaining more biological information and plays a positive role in further promoting the development of medical imaging, tumor treatment and other technologies. In addition, near-infrared light can also be used in biometrics, such as fingerprint recognition, iris recognition, and face recognition. Near-infrared light can also be used in LEDs. The new broadband infrared LED launched by OSRAM Opto Semiconductors applies phosphor technology to infrared emitters for the first time, resulting in the successful creation of an LED that can emit broadband infrared light in the wavelength range of 600nm to 1100nm. It has pioneered infrared spectroscopy technology suitable for the consumer goods market and is used in the food industry, agriculture and other industries to measure the moisture, fat, carbohydrates, sugar or protein content in food.

[0005] Similarly, stress luminescent materials are also a type of functional materials that have emerged in recent years. Unlike photoluminescent materials that require excitation light sources such as X-rays, ultraviolet rays, and visible light to excite and emit light, stress luminescent materials can produce luminescence when subjected to corresponding mechanical stimulation. This feature makes stress luminescent materials have strong application potential in various fields. Near-infrared stress luminescent materials combine the luminescence characteristics of stress luminescence and near-infrared, giving them deeper application prospects in the medical field. Summary of the invention

[0006] The purpose of the present invention is to provide a near-infrared stress phosphor and a preparation method thereof, so as to provide more choices for the market demand for near-infrared materials.

[0007] The present invention is achieved in that:

[0008] A near-infrared stress phosphor, the general chemical formula of which is: MgGa 2-x Cr x O 4 , where 0<x≤0.05.

[0009] Preferably, when the chemical formula is 0.01≤x≤0.04, the stress luminescence intensity of the near-infrared stress phosphor within the preferred range is relatively strong; more preferably, when the chemical formula is 0.025≤x≤0.03, the luminescence intensity of the near-infrared stress phosphor within the preferred range is relatively stronger; most preferably, when x=0.025 in the chemical formula, the luminescence intensity of the near-infrared stress phosphor is the strongest.

[0010] The present invention also provides a method for preparing a near-infrared stress phosphor, comprising the following steps:

[0011] (a) According to the chemical formula of phosphor: MgGa 2-x Cr x O 4 The molar ratio of each element in the above chemical formula is 0<x≤0.05. The oxides containing Mg, Ga and Cr elements are weighed, mixed and ground to obtain a mixture.

[0012] (b) The mixture is heated to 500° C. and calcined for 0.5 h, and then heated to 1300° C. and calcined for 6 h, and then cooled to room temperature to obtain a sintered body.

[0013] (c) Grinding the obtained sintered body sufficiently to obtain near-infrared stress phosphor.

[0014] The grinding time in step (a) is 15-30 min.

[0015] The heating rate in step (b) is 5-10°C / min.

[0016] In the preparation method of the near-infrared stress phosphor provided by the present invention, step (a) weighing oxides containing Mg, Ga, and Cr elements is specifically: MgO (99.9%), Ga 2 O 3 (99.9%), Cr 2 O 3 (99%).

[0017] The near-infrared stress phosphor prepared by the present invention has a wide excitation wavelength range, high luminous intensity, good stability, high quantum efficiency and high photoelectric conversion efficiency. 3+ A new type of near-infrared stress fluorescent material synthesized by ion doping adopts a high-temperature solid-phase preparation method with simple preparation process, easy operation and control, high safety, short preparation time, high production efficiency, and greatly reduced production cost compared with the existing technology. It is suitable for industrial large-scale production and promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the X-ray diffraction spectrum of the phosphor prepared in Examples 1-7 of the present invention and the standard sample.

[0019] Figure 2 These are the excitation and emission spectra of the phosphor prepared in Example 3 of the present invention.

[0020] Figure 3 is the stress luminescence intensity of the phosphors prepared in Examples 1-7 of the present invention. DETAILED DESCRIPTION

[0021] The following examples are used to further illustrate the present invention, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0022] Example 1

[0023] (1) Weigh the following raw materials: 0.3664 g of magnesium oxide (MgO), 0.3664 g of gallium oxide (Ga 2 O 3 )1.6955g, chromium trioxide (Cr 2 O 3 )0.0069 g, mix well, put it in an agate mortar and grind it thoroughly for 30 min to obtain a mixture.

[0024] (2) The ground mixture powder is placed in a small crucible, heated to 500°C at a heating rate of 5°C / min, sintered at this temperature for 0.5 h, and then heated to 1300°C at a heating rate of 5°C / min, sintered again at this temperature for 6 h, and naturally cooled to room temperature to obtain a sintered body.

[0025] (3) The obtained sintered body is fully ground to obtain a 1.99 Cr 0.01 O 4 Near-infrared stress phosphor.

[0026] The near-infrared stress phosphor prepared in this embodiment has strong near-infrared photoluminescence and stress luminescence.

[0027] Example 2

[0028] (1) Weigh the following raw materials: 0.3664 g of magnesium oxide (MgO), 0.3664 g of gallium oxide (Ga 2 O 3 )1.6870g, chromium trioxide (Cr 2 O 3 )0.0138 g, mix well, put it in an agate mortar and grind it thoroughly for 30 min to obtain a mixture.

[0029] (2) The ground mixture powder is placed in a small crucible, heated to 500°C at a heating rate of 5°C / min, sintered at this temperature for 0.5 h, and then heated to 1300°C at a heating rate of 5°C / min, sintered again at this temperature for 6 h, and naturally cooled to room temperature to obtain a sintered body.

[0030] (3) The obtained sintered body is fully ground to obtain a 1.98 Cr 0.02 O 4 Near-infrared stress phosphor.

[0031] The near-infrared stress luminescence intensity of the near-infrared stress phosphor prepared in this embodiment is equivalent to that in Embodiment 1.

[0032] Example 3

[0033] (1) Weigh the following raw materials: 0.3664 g of magnesium oxide (MgO), 0.3664 g of gallium oxide (Ga 2 O 3 )1.6827g, chromium trioxide (Cr 2 O 3 )0.0173 g, mix well, put it in an agate mortar and grind it thoroughly for 30 min to obtain a mixture.

[0034] (2) The ground mixture powder is placed in a small crucible, heated to 500°C at a heating rate of 5°C / min, sintered at this temperature for 0.5 h, and then heated to 1300°C at a heating rate of 5°C / min, sintered again at this temperature for 6 h, and naturally cooled to room temperature to obtain a sintered body.

[0035] (3) The obtained sintered body is fully ground to obtain a 1.975 Cr 0.025 O 4 Near-infrared stress phosphor.

[0036] The near-infrared stress luminescence intensity of the near-infrared stress phosphor prepared in this embodiment is about 3.5 times that of Embodiment 1 or 2. The near-infrared stress luminescence intensity of the near-infrared stress phosphor prepared in this embodiment reaches the highest.

[0037] Example 4

[0038] (1) Weigh the following raw materials: 0.3664 g of magnesium oxide (MgO), 0.3664 g of gallium oxide (Ga 2 O 3 )1.6801g, chromium trioxide (Cr 2 O 3 )0.0193 g, mix well, put it in an agate mortar and grind it thoroughly for 30 min to obtain a mixture.

[0039] (2) The ground mixture powder is placed in a small crucible, heated to 500°C at a heating rate of 5°C / min, sintered at this temperature for 0.5 h, and then heated to 1300°C at a heating rate of 5°C / min, sintered again at this temperature for 6 h, and naturally cooled to room temperature to obtain a sintered body.

[0040] (3) The obtained sintered body is fully ground to obtain a 1.972 Cr 0.028 O 4 Near-infrared stress phosphor.

[0041] Compared with Example 3, the near-infrared stress luminescence intensity of the near-infrared stress phosphor prepared in this example is reduced, but still higher than that of Examples 1 and 2.

[0042] Example 5

[0043] (1) Weigh the following raw materials: 0.3664 g of magnesium oxide (MgO), 0.3664 g of gallium oxide (Ga 2 O 3 )1.6784g, chromium trioxide (Cr 2 O 3 )0.0207 g, mix well, put it in an agate mortar and grind it thoroughly for 30 min to obtain a mixture.

[0044] (2) The ground mixture powder is placed in a small crucible, heated to 500°C at a heating rate of 5°C / min, sintered at this temperature for 0.5 h, and then heated to 1300°C at a heating rate of 5°C / min, sintered again at this temperature for 6 h, and naturally cooled to room temperature to obtain a sintered body.

[0045] (3) The obtained sintered body is fully ground to obtain a 1.97 Cr 0.03 O 4 Near-infrared stress phosphor.

[0046] Compared with Example 4, the near-infrared stress luminescence intensity of the near-infrared stress phosphor prepared in this example continues to decrease, but is still higher than that of Examples 1 and 2.

[0047] Example 6

[0048] (1) Weigh the following raw materials: 0.3664 g of magnesium oxide (MgO), 0.3664 g of gallium oxide (Ga 2 O 3 )1.6742g, chromium trioxide (Cr 2 O 3 )0.0242 g, mix well, put it in an agate mortar and grind it thoroughly for 30 min to obtain a mixture.

[0049] (2) The ground mixture powder is placed in a small crucible, heated to 500°C at a heating rate of 5°C / min, sintered at this temperature for 0.5 h, and then heated to 1300°C at a heating rate of 5°C / min, sintered again at this temperature for 6 h, and naturally cooled to room temperature to obtain a sintered body.

[0050] (3) The obtained sintered body is fully ground to obtain a 1.965 Cr 0.035 O 4 Near-infrared stress phosphor.

[0051] Compared with Example 5, the near-infrared stress luminescence intensity of the near-infrared stress phosphor prepared in this example continues to decrease, but is still higher than that of Examples 1 and 2.

[0052] Example 7

[0053] (1) Weigh the following raw materials: 0.3664 g of magnesium oxide (MgO), 0.3664 g of gallium oxide (Ga 2 O 3 )1.6699g, chromium trioxide (Cr 2 O 3 )0.0276 g, mix well, put it in an agate mortar and grind it thoroughly for 30 min to obtain a mixture.

[0054] (2) The ground mixture powder is placed in a small crucible, heated to 500°C at a heating rate of 5°C / min, sintered at this temperature for 0.5 h, and then heated to 1300°C at a heating rate of 5°C / min, sintered again at this temperature for 6 h, and naturally cooled to room temperature to obtain a sintered body.

[0055] (3) The obtained sintered body is fully ground to obtain a 1.96 Cr 0.04 O 4 Near-infrared stress phosphor.

[0056] The near-infrared stress luminescence intensity of the near-infrared stress phosphor prepared in this embodiment is comparable to that of embodiments 1 and 2.

[0057] Example 8: Testing the performance of the prepared phosphor

[0058] Experimental methods:

[0059] Detection of the phosphor MgGa prepared in Examples 1-7 1.99 Cr 0.01 O 4 (x = 0.01), MgGa 1.98 Cr 0.02 O4 (x = 0.02), MgGa 1.975 Cr 0.025 O 4 (x = 0.025), MgGa 1.972 Cr 0.028 O 4 (x=0.028),MgGa 1.97 Cr 0.03 O 4 (x = 0.03), MgGa 1.965 Cr 0.035 O 4 (x = 0.0.035) and MgGa 1.96 Cr 0.04 O 4 (x = 0.04) and the X-ray diffraction pattern compared with the standard sample card PDF10-0113, such as Figure 1 shown.

[0060] Example 3: Sample MgGa prepared 1.975 Cr 0.025 O 4 The excitation and emission spectra of Figure 2 As shown in the figure, the excitation wavelength λ ex =423nm, emission wavelength λ em =724nm.

[0061] Detection of the phosphor MgGa prepared in Examples 1-7 1.99 Cr 0.01 O 4 (x = 0.01), MgGa 1.98 Cr 0.02 O 4 (x = 0.02), MgGa 1.975 Cr 0.025 O 4 (x = 0.025), MgGa 1.972 Cr 0.028 O 4 (x=0.028),MgGa 1.97 Cr 0.03 O 4 (x = 0.03), MgGa 1.965 Cr 0.035 O 4 (x = 0.0.035) and MgGa 1.96 Cr 0.04 O 4 The emission spectrum of the material is as follows: Figure 3As shown. Figure 3 It can be seen that the stress luminescence intensity of the near-infrared stress phosphors prepared in Examples 3-5 is relatively strong; in particular, the stress luminescence intensity of the phosphor prepared in Example 3 is the strongest.

Claims

1. A near-infrared stress phosphor, Its characteristics are: Its chemical formula is: MgGa 2-x Cr x O 4 , where 0<x≤0.

05.

2. The near-infrared stress phosphor according to claim 1, Its characteristics are: The value range of x is 0.025≤x≤0.

03.

3. The near-infrared stress phosphor according to claim 2, Its characteristics are: x＝0.025。 4. A method for preparing near-infrared stress phosphor, Its characteristics include Follow these steps: a. According to the chemical formula of phosphor: MgGa 2-x Cr x O 4 The molar ratio of each element in the above formula is 0<x≤0.

05. The oxides containing Mg, Ga and Cr are weighed, mixed and ground to obtain a mixture. b. The mixture in step a is heated to 500° C. and calcined for 0.5 h, then continued to be heated to 1300° C. and calcined for 6 h, and then cooled to room temperature to obtain a sintered body; c. Grind the obtained sintered body thoroughly to obtain near-infrared stress phosphor.

5. The method for preparing the near-infrared stress phosphor according to claim 4, Its characteristics are: The grinding time in step a is 15-30 min.

6. The method for preparing the near-infrared stress phosphor according to claim 4, Its characteristics are: The heating rate in step b is 5-10°C / min.

7. The method for preparing the near-infrared stress phosphor according to claim 4, Its characteristics are: The value range of x in step a is 0.025≤x≤0.03.

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