Background
The rare earth doped luminescent nano-particles have wide application prospect in the fields of biomedicine and the like due to the unique luminescent property, so that more and more attention is drawn. When the rare earth nanoparticles are actually applied as a biological fluorescent probe, the interaction between the rare earth nanoparticles and biological macromolecules such as protein, DNA and the like in organisms can be possibly generated, the structure and the function of the biological macromolecules are further influenced, and unknown physiological effects are generated, so that the research on the interaction between the rare earth fluorescent nanoparticles and the proteins has important practical significance on the development of nano biomedicine and the evaluation on the use safety of the rare earth nanoparticles. The affinity of the fluorescent powder changed by the surfactant and the like to organisms can be combined with certain specific sites of the gene, and the gene is marked by the fluorescent powder, so that the application of the principle of selective expression of the gene and the like is explored. Therefore, the research of the fluorescent powder has certain auxiliary potential value for the marking research in the biological fields of genetic engineering, protein engineering, cell engineering and the like. At present, the research on the interaction between rare earth nanoparticles and proteins is very rare, and according to the literature reports, people found that rare earth compounds have some special pharmacological effects, such as anticoagulant effect, anti-inflammatory and bactericidal effect, anti-arteriosclerosis effect, anti-cancer effect and the like in the last 60 th century. Moreover, studies have shown that the toxicity of rare earth complexes is lower than that of some transition metal complexes and partially organically synthesized drugs.
The traditional organic fluorescent dye has poor photochemical stability, wide absorption and emission bands, serious photobleaching and photolysis, and the photolysis product has a killing effect on organisms, thereby greatly limiting the application range of the organic fluorescent dye. However, the semiconductor fluorescent nanocrystals widely studied in recent years have poor chemical stability and unavoidable biological toxicity, and thus their applications are still limited. In comparison, the rare earth nano material has unique physical properties of light, electricity, magnetism and the like, and has small biological toxicity, so the rare earth nano material has wide application prospect in the biological imaging technology. At present, the development of the field of nano-particle phosphors is restricted by the technical problems of complex operation, high production cost, low yield, difficult control of product purity, unsatisfactory light stability and biocompatibility, high product crystallization temperature and the like of the preparation method of the rare earth doped luminescent nano-particles because toxic and harmful substances such as HF and the like are generated in the preparation process, so that the preparation method is not beneficial to people and environment.
Disclosure of Invention
The invention aims to provide a LaF3:Eu3+A nanoparticle phosphor.
Another object of the present invention is to provide the above LaF3:Eu3+A method for preparing a nanoparticle phosphor.
The purpose of the invention is realized by the following technical scheme:
LaF3:Eu3+A nanoparticle phosphor characterized by: the crystal form has a peak of correlation at diffraction angles 2 theta of 24.178 +/-0.2, 24.738 +/-0.2 degrees, 27.585 +/-0.2 degrees, 34.82 +/-0.2 degrees, 43.604 +/-0.2 degrees, 44.738 +/-0.2 degrees, 50.463 +/-0.2 degrees, 52.389 +/-0.2 degrees, 64.402 +/-0.2 degrees, 68.277 +/-0.2 degrees and 70.640 +/-0.2 degrees.
Specifically, the above-mentioned LaF3:Eu3+A nanoparticle phosphor characterized by: it has an X-ray powder diffraction pattern as shown in FIG. 1.
LaF of the invention3:Eu3+The shape of the nano-particle phosphor is that the nano-particles of fluffy long cotton candy are gathered, the particle size is 75-130 nm, and particularly LaF shown in figure 23:Eu3+SEM image of nanoparticle phosphor.
LaF3:Eu3+The preparation method of the nano-particle phosphor is characterized by comprising the following steps:
1. taking La (NO)3)3Solution, Eu (NO)3)3Placing the solution in a proper container, and stirring for 10-15 min by a magnetic stirrer for later use;
2. adding 1-butyl-3-methylimidazole tetrafluoroborate and a surfactant into the mixed solution obtained in the step 1, sealing, and stirring for 2-3 hours for later use; the surfactant is octadecyl ammonium thiophosphate, octadecyl sodium thiophosphate, polyvinylpyrrolidone, polyethyleneimine, sodium oleate, octadecene and polyethylene glycol 400; polyethylene glycol 12000; polyethylene glycol 6000; one or more of polyethylene glycol 2000;
3. transferring the mixed solution obtained in the step 2 to a polytetrafluoroethylene reaction kettle, then placing the reaction kettle in a drying oven, setting the temperature to be 170-190 ℃, reacting for 8-15 hours, and after the reaction is finished, placing the reaction kettle at room temperature to obtain a precipitate crude product 1 for later use;
4. transferring the precipitate crude product 1 obtained in the step 3 into a centrifuge tube, adding ethanol, washing, centrifuging by using a centrifuge at the rotation speed of 5000-7000 r/min for 5-7 min after each washing, pouring supernatant liquor after centrifuging to obtain a crude product 2, placing the crude product 2 in an oven, and drying for 6-8 hours at the drying temperature of 80-90 ℃ to obtain a finished product.
Further, in order to make the light stability of the nanoparticle phosphor better, a LaF3:Eu3+A method for producing a nanoparticle phosphor, characterized in that La (NO) described in step 13)3The solution concentration was 0.25mol/L, 19ml, the Eu (NO)3)3The concentration of the solution is 0.25mol/L, and the dosage is 1 ml;
further, in order to make the crystallization temperature of the nanoparticle phosphor higher and the dispersibility better, a LaF3:Eu3+The preparation method of the nanoparticle phosphor is characterized in that in the step 2, the mass of the 1-butyl-3-methylimidazole tetrafluoroborate is 2.8g, the surfactant is preferably a composite surfactant composed of polyvinylpyrrolidone and sodium oleate, the mass ratio of the composite surfactant to the surfactant is 1: 2-2.5, and the total using amount of the composite surfactant is 0.04 g.
In order to ensure the purity of the product and further improve the yield of the product, LaF3:Eu3+The preparation method of the nano-particle phosphor is characterized in that the ethanol in the step 4 is absolute ethanol, the addition amount of the absolute ethanol is 4-6 times of the mass of 1 of the crude precipitate, and the washing times are 3 times.
The invention has the following beneficial effects:
the invention relates to a LaF3:Eu3+The nano-particle phosphor has high purity and yield which can reach more than 93.8 percent, the product has better light stability and biocompatibility, the product has high crystallization temperature which can reach 178.3 ℃, and better crystallinity and dispersibility, and in addition, the toxic and harmful substances are less released in the preparation process, the product is friendly to human and environment, the luminous intensity of the product is high, the mass production is easy to realize, the preparation raw materials are simple and easy to obtain, the price is low, and the nano-particle phosphor is worthy of market popularization and application.
Detailed Description
The present invention is described in detail below by way of examples, it should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and those skilled in the art can make some insubstantial modifications and adaptations of the present invention based on the above-described disclosure.
Example 1
1. Taking 0.25mol/L La (NO)3)3Solution 19ml, 0.25mol/L Eu (NO)3)3Placing 1ml of the solution in a beaker, placing the beaker in a magnetic stirrer, and stirring for 10min for later use;
2. adding 2.8g of 1-butyl-3-methylimidazole tetrafluoroborate, 0.012g of polyvinylpyrrolidone and 0.028g of oleic acid into the mixed solution in the step 1, sealing, and stirring for 2 hours for later use;
3. transferring the mixed solution obtained in the step 2 to a polytetrafluoroethylene reaction kettle, then placing the reaction kettle in an oven, setting the temperature to be 170 ℃, reacting for 12 hours, and after the reaction is finished, placing the reaction kettle at room temperature to obtain a precipitate crude product 1 for later use;
4. transferring the precipitate crude product 1 obtained in the polytetrafluoroethylene reaction kettle in the step 3 into a centrifuge tube, adding absolute ethyl alcohol for washing for 3 times, wherein the use amount of the ethyl alcohol is 4 times of the mass of the crude product 1 each time, performing centrifugal treatment by using a centrifugal machine after washing each time is finished, rotating the centrifugal machine at 5000r/min, centrifuging for 5min, pouring supernatant liquor after centrifuging is finished, obtaining a crude product 2, placing the crude product 2 in a drying oven, and drying for 6h at the drying temperature of 80 ℃ to obtain a finished product.
The determination shows that the product yield is 93.8%, and the product crystallization temperature is 178.3 ℃.
Experiment one: stability test: the LaF obtained in example 1 was taken3:Eu3+The nano-particle phosphor finished product is placed in a common sealed plastic bag for 3 months, and is taken out after 3 months, and XRD test is carried out, and experimental results show that the X-ray diffraction pattern of the nano-particle phosphor finished product is not obviously changed, namely, the components of the nano-particle phosphor are not changed, the fluorescence intensity is compared with 0 day, the approximation degree reaches more than 99%, and the luminous intensity is not changed basically, so that the nano-particle phosphor finished product is considered to have good light stability.
Example 2
LaF prepared in example 13:Eu3+XRD test of the nano-particle phosphor:
adopts Dandong, TD-3500 and Chinese X-ray diffractometer, the radiation source is Cu Bak, the wavelength is 1.54060m, the scanning angle is 20-80 degrees, the voltage is 30kV, the current is 20mA, and the scanning speed is 2.4 degrees/min. The X-ray diffraction pattern of the X-ray nano-particles is shown in figure 1.
The LaF3: Eu3+The nanoparticle phosphor has an emission peak at a diffraction angle 2 theta of 24.178 + -0.2, 24.738 + -0.2 °, 27.585 + -0.2 °, 34.82 + -0.2 °, 43.604 + -0.2 °, 44.738 + -0.2 °, 50.463 + -0.2 °, 52.389 + -0.2 °, 64.402 + -0.2 °, 68.277 + -0.2 ° and 70.640 + -0.2 °.
LaF prepared in example 13:Eu3+The scanning result of the nano-particle phosphor is shown in figure 2.
From FIG. 2, LaF can be seen3:Eu3+The shape of the cotton candy is that fluffy long cotton candy nanoparticles are gathered, and the particle size is about 75-130 nm.
LaF prepared in example 13:Eu3+The fluorescent property of the nano-particle phosphor is tested, and the experimental result is shown in figure 3.
FIG. 3 shows the samples in LaF2.95:Eu0.05As can be seen from the graph, the monitored wavelength of the excitation spectrum of the sample is 590nm, which corresponds to Eu3+Of ions5D0→7F2Transition, the strongest peak is obviously seen at 396.8nm from the excitation spectrum, corresponding to Eu3+Of ions7F0→5L6And (4) transition. The wavelength of the emission spectrum was monitored at 397nm, with the strongest peak of the spectrum appearing at 592.0 nm.
Example 3
1. Taking 0.25mol/L La (NO)3)3Solution 19ml, 0.25mol/L Eu (NO)3)3Placing 1ml of the solution in a beaker, placing the beaker in a magnetic stirrer, and stirring for 15min for later use;
2. adding 2.8g of 1-butyl-3-methylimidazole tetrafluoroborate, 0.013g of polyvinylpyrrolidone and 0.027g of oleic acid into the mixed solution in the step 1, sealing, and stirring for 2 hours for later use;
3. transferring the mixed solution obtained in the step 2 to a polytetrafluoroethylene reaction kettle, then placing the reaction kettle in an oven, setting the temperature to be 190 ℃, reacting for 8 hours, and after the reaction is finished, placing the reaction kettle at room temperature to obtain a precipitate crude product 1 for later use;
4. transferring the precipitate crude product 1 obtained in the polytetrafluoroethylene reaction kettle in the step 3 into a centrifuge tube, adding absolute ethyl alcohol for washing for 3 times, wherein the use amount of the ethyl alcohol is 6 times of the mass of the crude product 1 each time, a centrifuge is required for centrifugal treatment after each time of washing is finished, the rotation speed of the centrifuge is 7000r/min, the centrifugation time is 7min, after the centrifugation is finished, pouring supernatant liquor to obtain a crude product 2, placing the crude product 2 into an oven, and setting the drying temperature to be 90 ℃ for drying for 8h to obtain a finished product.
The determination shows that the product yield is 94.2%, and the product crystallization temperature is 178.7 ℃.
Experiment one: stability test: the LaF obtained in example 3 was taken3:Eu3+The nano-particle phosphor finished product is placed in a common sealed plastic bag for 3 months, and is taken out after 3 months, and XRD test is carried out, and experimental results show that the X-ray diffraction pattern of the nano-particle phosphor finished product is not obviously changed, namely, the components of the nano-particle phosphor are not changed, the fluorescence intensity is compared with 0 day, the approximation degree reaches more than 99%, and the luminous intensity is not changed basically, so that the nano-particle phosphor finished product is considered to have good light stability.
Example 4
1. Taking 0.25mol/L La (NO)3)3Solution 19ml, 0.25mol/L Eu (NO)3)3Placing 1ml of the solution in a beaker, placing the beaker in a magnetic stirrer, and stirring for 13min for later use;
2. adding 2.8g of 1-butyl-3-methylimidazole tetrafluoroborate, 0.011g of polyvinylpyrrolidone and 0.029g of oleic acid into the mixed solution in the step 1, sealing, and stirring for 3 hours for later use;
3. transferring the mixed solution obtained in the step 2 to a polytetrafluoroethylene reaction kettle, then placing the reaction kettle in an oven, setting the temperature to be 180 ℃, reacting for 13 hours, and after the reaction is finished, placing the reaction kettle at room temperature to obtain a precipitate crude product 1 for later use;
4. transferring the precipitate crude product 1 obtained in the polytetrafluoroethylene reaction kettle in the step 3 into a centrifugal tube, adding absolute ethyl alcohol for washing for 3 times, wherein the use amount of the ethyl alcohol is 5 times of the mass of the crude product 1 each time, performing centrifugal treatment by using a centrifugal machine after washing each time, rotating the centrifugal machine at 6000r/min, centrifuging for 6min, pouring supernatant liquid after centrifuging to obtain a crude product 2, placing the crude product 2 in a drying oven, and drying for 7h at the drying temperature of 85 ℃ to obtain a finished product.
The product yield is 94.6% and the product crystallization temperature is 179.1 ℃ by determination.
Experiment one: stability test: LaF from example 4 was used3:Eu3+The nano-particle phosphor finished product is placed in a common sealed plastic bag for 3 months, and is taken out after 3 months, and XRD test is carried out, and experimental results show that the X-ray diffraction pattern of the nano-particle phosphor finished product is not obviously changed, namely, the components of the nano-particle phosphor are not changed, the fluorescence intensity is compared with 0 day, the approximation degree reaches more than 99%, and the luminous intensity is not changed basically, so that the nano-particle phosphor finished product is considered to have good light stability.