Broadband near-infrared stress luminescent material without pre-irradiation as well as preparation method and application of broadband near-infrared stress luminescent material

Abstract

The invention discloses a broadband near-infrared stress luminescent material without pre-irradiation as well as a preparation method and application of the broadband near-infrared stress luminescent material. The material is La < 3 > Ga < 5-5x > GeO < 14: 5x > Cr < 3 + >, wherein x is greater than or equal to 0.0025 and less than or equal to 0.02; the crystal structure belongs to a P321 trigonal system structure, and the active ion is Cr < 3 + >. The preparation method comprises the following steps: respectively weighing a lanthanum-containing compound raw material, a gallium-containing compound raw material, a germanium-containing compound raw material and a chromium-containing compound raw material, uniformly grinding the raw materials, grinding, pre-sintering, calcining, cooling to room temperature along with a furnace, and grinding to obtain the near-infrared stress luminescent material without pre-irradiation. The material disclosed by the invention shows broadband emission in a near-infrared 1 region range, and has good self-energy-supply performance, the stress luminescence intensity can be self-recovered, and the stress luminescence intensity can be kept at a considerable level even if force circulation times are continuously applied for multiple times. The material can be used for preparing a stress luminescent film suitable for biological physiological parameter detection.

Description

Technical Field

[0001] This invention relates to the field of luminescent materials, and in particular to a broadband near-infrared stress luminescent material that does not require pre-irradiation, its preparation method, and its application. Background Technology

[0002] Stress luminescence refers to the luminescence phenomenon produced by materials under external mechanical stress (such as compression, tension, or friction). Due to its unique force-light conversion characteristics, stress luminescent materials have broad application prospects in stress detection, structural health monitoring, and non-destructive testing. In particular, near-infrared stress luminescent materials, due to their strong penetrating power, can effectively reduce autofluorescence interference in biological tissues, making them suitable for deep imaging and monitoring, especially in the biomedical field, enabling more precise detection of physiological parameters.

[0003] However, most current near-infrared stress-luminescent materials rely on defect control and require pre-irradiation charging from an external light source. High-energy irradiation often produces long afterglow luminescence, and these interfering signals further reduce the "purity" of the ML signal, affecting its accuracy and thus limiting its operability in biomedicine.

[0004] Patent CN112063382A proposes a stress material that does not require pre-irradiation and can instantly self-recover luminescence, utilizing Cr 3+ Doping to achieve stress luminescence (LiGa) 5-5x O8:5xCr 3+ This material emits light without external irradiation and possesses self-healing properties, making it suitable for applications such as smart electronic signatures, stress sensors, and bio-stress imaging. However, its emission wavelength is relatively narrow, mainly concentrated around 700 nm, which limits its flexibility and versatility in bio-imaging. Summary of the Invention

[0005] To overcome the aforementioned shortcomings and deficiencies of existing technologies, the purpose of this invention is to provide near-infrared stress-luminescent materials that do not require pre-irradiation. The emission peak is located at 790 nm, generating broadband near-infrared stress luminescence in the 650-1000 nm near-infrared band, achieving near-infrared stress luminescence without the need for pre-irradiation. This invention employs a high-temperature solid-state reaction, resulting in simple preparation conditions and facilitating mass production.

[0006] Another objective of this invention is to provide a method for preparing a near-infrared stress-luminescent material that does not require pre-irradiation and its application.

[0007] The objective of this invention is achieved through the following technical solution: This invention proposes a novel self-powered near-infrared stress-luminescent material, La3Ga, which requires no pre-irradiation. 5- 5x GeO14 :5xCr 3+ (where x is Cr) 3+ (Mole fraction, 0.0025 ≤ x ≤ 0.02). This material does not require a pre-irradiation process, thus overcoming the limitations of existing materials and further expanding its application potential in biomedical imaging and physiological parameter monitoring (such as blood oxygen saturation detection).

[0008] A near-infrared stress-luminescent material that does not require pre-irradiation, with the general chemical formula La3Ga 5-5x GeO 14 :5xCr 3 + , where x is Cr 3+ Mole fraction, 0.0025 ≤ x ≤ 0.02.

[0009] A method for preparing a near-infrared stress-luminescent material without pre-irradiation includes the following steps: S1) According to the general chemical formula La3Ga 5-5x GeO 14 :5xCr 3+ (x is Cr) 3+ Mole fraction (0.0025≤x≤0.02), weigh out lanthanum-containing compound raw materials, gallium-containing compound raw materials, germanium-containing compound raw materials and chromium-containing compound raw materials respectively, grind and mix them evenly to obtain a mixture; S2) Mix and grind the raw materials from step S1) uniformly and pre-calcine at 800-1000℃ for 2-5 hours, controlling the heating rate at 5-10℃ / min during the process. Continue to calcine at 1100-1600℃ for 2-10 hours. After cooling to room temperature in the furnace, grind to obtain the near-infrared stress luminescent material that does not require pre-irradiation.

[0010] In the above method, in step S1), the lanthanum-containing compound raw material is either lanthanum oxide or lanthanum nitrate.

[0011] In the above method, in step S1), the gallium-containing compound raw material is either gallium oxide or gallium nitrate.

[0012] In the above method, in step S1), the germanium-containing compound raw material is either germanium dioxide or germanium nitrate.

[0013] In the above method, in step S1), the chromium-containing compound raw material is either chromium trioxide or chromium nitrate.

[0014] In the above method, in step S1), the preferred molar ratio of the lanthanum-containing compound raw material, the gallium-containing compound raw material, the germanium-containing compound raw material, and the chromium-containing compound raw material is La:Ga:Ge:Cr = 3:4.9:1:0.1.

[0015] The near-infrared stress-luminescent material prepared by the above method without pre-irradiation has a crystal structure belonging to P. 321 Trigonal crystal structure, with Cr as the activating ion. 3+ .

[0016] The above method prepares a near-infrared stress-luminescent material that does not require pre-irradiation, which is used to encapsulate a flexible and transparent low-density polyethylene (LDPE) film into a stress-luminescent thin film.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) The La3Ga of the present invention 5-5x GeO 14 :5xCr 3+ (0.0025≤x≤0.02) The emission band of the near-infrared stress-luminescent material covers the near-infrared region of 650-1000 nm, with the main emission peak located at 737 nm, exhibiting significant broadband emission characteristics (FWHM = 162 nm), and possessing excellent imaging performance in penetrating deep tissues.

[0018] (2) The La3Ga of the present invention 5-5x GeO 14 :5xCr 3+ (0.0025≤x≤0.02) Near-infrared stress-luminescent materials have a low activation threshold and do not require external light source pre-excitation or pre-irradiation, exhibiting excellent self-powered characteristics, making them suitable for long-term, repeated use in biological monitoring and stress detection applications.

[0019] (3) The La3Ga of the present invention 5-5x GeO 14 :5xCr 3+ (0.0025≤x≤0.02) Near-infrared stress-luminescent materials have good structural stability, can be prepared by simple synthesis methods, are easy to mass-produce, and have broad application prospects, especially in the fields of bioimaging and real-time monitoring. Attached Figure Description

[0020] Figure 1 The XRD patterns of the samples with proportions (1)-(5) in Example 1 of the present invention are shown.

[0021] Figure 2 The stress emission spectrum of sample (5) in embodiment 1 of the present invention is shown. Figure 3 This is a demonstration of the biological penetration and imaging application of the sample with ratio (5) in Example 1 of the present invention. Detailed Implementation

[0022] The present invention is further illustrated below through specific embodiments, but these are not intended to limit the invention. Various modifications and improvements made by those skilled in the art based on the basic idea of ​​the present invention, as long as they do not depart from the basic idea of ​​the present invention, are within the scope of the present invention.

[0023] Example 1 A near-infrared stress-luminescent material that does not require pre-irradiation and its preparation method, the method comprising the following steps: Lanthanum oxide, gallium oxide, germanium dioxide, and chromium oxide were selected as starting materials. The raw materials were weighed according to the stoichiometric ratio of each element, resulting in a total of 5 groups. The proportions are as follows: (All proportions below refer to molar ratios) (1) La: Ga: Ge: Cr = 3:5:1:0 corresponds to x = 0.00; (2) La: Ga: Ge: Cr = 3:4.9875:1:0.0125 corresponds to x = 0.0025; (3) La: Ga: Ge: Cr = 3:4.975:1:0.025 corresponds to x = 0.005; (4) La: Ga: Ge: Cr = 3:4.95:1:0.05 corresponds to x = 0.01; (5) La: Ga: Ge: Cr = 3:4.9:1:0.1 corresponds to x = 0.02; After the mixture is ground and mixed evenly, it is placed into an alumina crucible; the alumina crucible is then placed in a high-temperature box furnace. The heating rate is strictly controlled at 5℃ / min, and the mixture is pre-calcined at 800℃ for 2 hours, cooled to room temperature, and ground and mixed evenly; then it is calcined at 1250℃ for 5 hours, cooled to room temperature in the furnace, and ground to obtain the target near-infrared stress luminescent material, that is, a near-infrared stress luminescent material that does not require pre-irradiation.

[0024] Figure 1 The XRD patterns of the near-infrared stress-luminescent materials obtained according to proportions (1)-(5) in Example 1 are shown. Cu target Kα rays were used as the irradiation source, with a test voltage of 40 kV, a current of 40 mA, a scan step size of 0.02° / step, and a scan speed of 0.12 s / step. XRD pattern analysis results indicate that the sample obtained after holding at 1250℃ for 5 hours is La3Ga5GeO. 14 The structure is intact and no other impurity phases have been introduced.

[0025] Figure 2The stress emission spectrum of the sample obtained according to the ratios (2)-(5) in Example 1 covers the emission band of 600-1000 nm. The stress emission detection system of this invention was self-built and includes two parts: a stress application system and a spectral collection system. A uniaxial universal testing machine (model: CMT1104, range 10 kN, accuracy class 0.5) is used to apply compressive stress. The optical signal collection system consists of a laptop computer (Lenovo ThinkPad E480), a spectrometer, and a compatible fiber optic probe. The spectrometer is manufactured by Marine Optics, Inc., and uses a QE65pro for signal detection in the visible band (300-1000 nm), equipped with a Hamamatsu FFT-CCD detector. Figure 2 It can be seen that under a stress stimulus of 25 N, all samples can produce near-infrared stress emission centered at approximately 737 nm, with a wavelength range covering 600-1000 nm, corresponding to Cr 3+ of 4 T1→ 4 A2 transition. With Cr... 3+ As the doping concentration increases, the emission peak intensity gradually increases, the emission peak redshifts, and the full width at half maximum (FWHM) increases.

[0026] Example 2 Lanthanum oxide, gallium oxide, germanium dioxide, and chromium trioxide were selected as starting materials, with a molar ratio of La:Ga:Ge:Cr = 3:4.9:1:0.1, corresponding to x = 0.02. The four compounds were weighed separately, and the mixture was ground and homogenized before being placed in an alumina crucible and then placed in a high-temperature box furnace. The heating rate was strictly controlled at 5℃ / min, and the mixture was pre-calcined at 800℃ for 2 hours. After cooling to room temperature, it was ground and homogenized; then calcined at 1100℃ for 2 hours, cooled to room temperature in the furnace, and ground again to obtain the near-infrared stress-luminescent material that does not require pre-irradiation. Spectroscopic analysis was performed according to the method in Example 1, and the results were similar to those in Example 1.

[0027] Example 3 Lanthanum oxide, gallium oxide, germanium dioxide, and chromium trioxide were selected as starting materials, with a molar ratio of La:Ga:Ge:Cr = 3:4.9:1:0.1, corresponding to x = 0.02. The four compounds were weighed separately, and the mixture was ground and homogenized before being placed in an alumina crucible and then placed in a high-temperature box furnace. The heating rate was strictly controlled at 5℃ / min, and the mixture was pre-calcined at 800℃ for 2 hours. After cooling to room temperature, it was ground and homogenized; then calcined at 1200℃ for 5 hours, and after cooling to room temperature in the furnace, it was ground again to obtain the near-infrared stress-luminescent material that does not require pre-irradiation. Spectroscopic analysis was performed according to the method in Example 1, and the results were similar to those in Example 1.

[0028] Example 4 Lanthanum oxide, gallium oxide, germanium dioxide, and chromium trioxide were selected as starting materials, with a molar ratio of La:Ga:Ge:Cr = 3:4.9:1:0.1, corresponding to x = 0.02. The four compounds were weighed separately, and the mixture was ground and homogenized before being placed in an alumina crucible and then placed in a high-temperature box furnace. The heating rate was strictly controlled at 5℃ / min, and the mixture was pre-calcined at 800℃ for 2 hours. After cooling to room temperature, it was ground and homogenized; then calcined at 1300℃ for 7 hours, and after cooling to room temperature in the furnace, it was ground again to obtain the near-infrared stress-luminescent material that does not require pre-irradiation. Spectroscopic analysis was performed according to the method in Example 1, and the results were similar to those in Example 1.

[0029] Example 5 Lanthanum oxide, gallium oxide, germanium dioxide, and chromium trioxide were selected as starting materials, with a molar ratio of La:Ga:Ge:Cr = 3:4.9:1:0.1, corresponding to x = 0.02. The four compounds were weighed separately, and the mixture was ground and homogenized before being placed in an alumina crucible and then placed in a high-temperature box furnace. The heating rate was strictly controlled at 5℃ / min, and the mixture was pre-calcined at 800℃ for 2 hours. After cooling to room temperature, it was ground and homogenized; then calcined at 1400℃ for 10 hours, and after cooling to room temperature in the furnace, it was ground to obtain the near-infrared stress-luminescent material that does not require pre-irradiation. Spectroscopic analysis was performed according to the method of Example 1, and the results were similar to those of Example 1.

[0030] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the embodiments described above. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A near-infrared stress-luminescent material that does not require pre-irradiation, characterized in that, The general chemical formula is La3Ga 5- 5x GeO 14 :5xCr 3+ , where x is Cr 3+ Mole fraction, 0.0025 ≤ x ≤ 0.02; has P 321 Trigonal crystal structure, luminescent ion is Cr 3+ .

2. The method for preparing a near-infrared stress-luminescent material without pre-irradiation as described in claim 1, characterized in that, Includes the following steps: S1) According to the general chemical formula La3Ga 5-5x GeO 14 :5xCr 3+ Weigh out lanthanum-containing compound raw materials, gallium-containing compound raw materials, germanium-containing compound raw materials and chromium-containing compound raw materials respectively, grind and mix them evenly to obtain a mixture; S2) The mixture obtained in step S1) is pre-calcined while controlling the heating rate, then calcined, cooled to room temperature in the furnace, and then ground to obtain a near-infrared stress luminescent material that does not require pre-irradiation.

3. The method for preparing a near-infrared stress-luminescent material without pre-irradiation according to claim 2, characterized in that, The lanthanum-containing compound raw material mentioned in step S1) is either lanthanum oxide or lanthanum nitrate.

4. The method for preparing a near-infrared stress-luminescent material without pre-irradiation according to claim 2, characterized in that, The gallium-containing compound raw material mentioned in step S1) is either gallium oxide or gallium nitrate.

5. The method for preparing a near-infrared stress-luminescent material without pre-irradiation according to claim 2, characterized in that, The germanium-containing compound raw material mentioned in step S1) is one of germanium dioxide or germanium nitrate.

6. The method for preparing a near-infrared stress-luminescent material without pre-irradiation according to claim 2, characterized in that, The chromium-containing compound raw material mentioned in step S1) is either chromium trioxide or chromium nitrate.

7. The method for preparing a near-infrared stress-luminescent material without pre-irradiation according to claim 2, characterized in that, In step S1), the molar ratio of the lanthanum-containing compound raw material, the gallium-containing compound raw material, the germanium-containing compound raw material, and the chromium-containing compound raw material is 3:4.9:1:0.

1.

8. The method for preparing a near-infrared stress-luminescent material without pre-irradiation according to claim 2, characterized in that, The pre-firing temperature in step S2) is 800-1000℃, the pre-firing time is 2-5h, and the heating rate is controlled at 5-10℃ / min during the process.

9. The method for preparing a near-infrared stress-luminescent material without pre-irradiation according to claim 2, characterized in that, The calcination temperature in step S2) is 1100-1600℃, and the calcination time is 2-10h.

10. The application of the near-infrared stress-luminescent material without pre-irradiation as described in claim 1 in a flexible and transparent low-density polyethylene stress-luminescent film.

Images