A Mg 2+ Method for preparing Eu-containing amorphous calcium carbonate luminescent nanomaterials mediated by

Abstract

The application discloses a kind of Mg 2+ Preparation method of Eu-containing amorphous calcium carbonate luminescent nanomaterial under mediation, belong to solid-state photoluminescence material technical field.The present application first prepares mineralization mother liquor with Ca salt, Eu salt and Mg salt as raw material, then through ammonium carbonate diffusion method (ADM), make (NH4)2CO3 solid decompose into CO2 and NH3, and make it diffuse through gas-liquid interface into mother liquor and carry out mineralization reaction, and at this time, the existence of Mg 2+ Delay the nucleation and growth of calcite and aragonite and other crystal forms, prolong the life of amorphous calcium carbonate and seal Eu 3+ In the structure of amorphous calcium carbonate, and then a rare earth doped Eu-containing amorphous calcium carbonate luminescent nanomaterial with high concentration and highly uniform distribution is obtained.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of solid-state photoluminescence materials, and particularly relates to a preparation method of Eu-containing amorphous calcium carbonate luminescent nanomaterials mediated by Mg 2+ . BACKGROUND

[0002] Nanometer calcium carbonate materials are widely used in industry, agriculture and manufacturing due to their high specific surface area, good dispersibility and enhanced performance. In the industrial field, nanometer calcium carbonate is mainly used as a reinforcing filler in plastic and rubber materials, which can significantly improve the strength and durability of the materials, especially in the automobile and electronics manufacturing fields. In the agricultural field, it can be used as a soil conditioner to improve acidic soil and increase fertility, and can also be used as a carrier for pesticides and fertilizers to achieve controlled release. In the manufacturing field, nanometer calcium carbonate is used in coatings and coatings to improve wear resistance and corrosion resistance, and in paper production to enhance paper strength and smoothness. However, the preparation of nanometer calcium carbonate materials faces technical difficulties such as difficulty in controlling crystal, poor dispersibility, and the surface activity of calcite calcium carbonate is relatively low, which limits the combination ability with other materials and affects the performance of composite materials. Amorphous calcium carbonate materials have greater advantages in industry, agriculture and manufacturing compared to calcite calcium carbonate materials. Amorphous calcium carbonate has higher specific surface area and surface activity, which can better interact with other substances, enhance adsorption performance and reaction activity. For example, in agriculture, amorphous calcium carbonate is more easily reacted with acidic substances in the soil to quickly improve the soil environment; in manufacturing, the better dispersibility and adhesion of amorphous calcium carbonate make its performance in coatings and composite materials more stable and uniform.

[0003] Rare earth-doped nanometer calcium carbonate materials have broad application prospects in biomedical imaging, sensor detection, photocatalysis and other fields, and have gradually become a hot field in recent years. Rare earth elements (such as Eu 3+ , Tb 3+ , etc.) have unique fluorescence properties, which can be introduced into nanometer calcium carbonate materials by doping to endow the material with spectral response ability, and realize specific functions such as photocatalysis or biological imaging through light excitation, effectively overcoming its original limitations, endowing the material with new optical functions and expanding the application range of the material.

[0004] The existing synthesis method of rare earth doped calcium carbonate (such as CN112322286A, a different morphology of nano calcium carbonate luminescent material doped with rare earth ions and its preparation method and application) is mostly carbonization method, which needs to be prepared under high temperature conditions and has various problems. On the one hand, the product is usually calcite crystal type, and the grain size is difficult to control and the dispersity is poor; on the other hand, it is difficult to accurately control the concentration and distribution of rare earth doping, resulting in unstable performance of the material. Therefore, it is necessary to develop a synthesis method of rare earth doped nano calcium carbonate material which is more stable, has high dispersity and controllable doping concentration. SUMMARY

[0005] The present application aims at the problems of the existing preparation method of rare earth doped nano calcium carbonate material, such as the product being calcite crystal type, the grain size being difficult to control, the dispersity being poor, the concentration and distribution of rare earth doping being difficult to accurately control, and the performance being unstable, and proposes a preparation method of Eu-containing amorphous calcium carbonate luminescent nanomaterial under the mediation of Mg 2+ .

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] The present application provides a preparation method of Eu-containing amorphous calcium carbonate luminescent nanomaterial under the mediation of Mg 2+ . The preparation method comprises the following steps: preparing a mineralization mother liquor by taking Ca salt, Eu salt and Mg salt as raw materials; performing carbonate mineralization reaction on the mineralization mother liquor and ammonium carbonate powder by ammonium carbonate diffusion method (ADM), and then performing centrifugation and drying to obtain the Eu-containing amorphous calcium carbonate luminescent nanomaterial under the mediation of Mg 2+ .

[0008] Technical principle:

[0009] The present application first prepares a mineralization mother liquor by taking Ca salt, Eu salt and Mg salt as raw materials, and then performs carbonate mineralization reaction by ammonium carbonate diffusion method (ADM), so that (NH4)2CO3 solid is decomposed into CO2 and NH3, and diffuses through the gas-liquid interface into the mother liquor for mineralization reaction. At this time, the existence of Mg 2+ delays the nucleation and growth of calcite and aragonite and the like, prolongs the life of amorphous calcium carbonate, and encloses Eu 3+ in the structure of amorphous calcium carbonate, thereby obtaining the Eu-containing amorphous calcium carbonate luminescent nanomaterial with high rare earth doping concentration and highly uniform distribution.

[0010] Further, the molar concentration ratio of Ca 2+ , Eu 3+ and Mg 2+ in the mineralization mother liquor is 1:1:(1-5).

[0011] Further, the concentration of Ca in the mineralization mother liquor is 100 mmol / L, the concentration of Eu is 100 mmol / L, and the concentration of Mg is 100-500 mmol / L. 2+ 3+ 2+

[0012] Further, the Ca salt is selected from CaCl2, the Eu salt is selected from EuCl3, and the Mg salt is selected from MgCl2.

[0013] Further, the ratio of the volume of the mineralization mother liquor to the mass of the ammonium carbonate powder is 50:2 (mL / g).

[0014] Further, the temperature of the carbonate mineralization reaction is 20-30℃, and the reaction time is 11-12h.

[0015] Further, the centrifugation is specifically as follows: after the reaction solution obtained after the carbonate mineralization reaction is centrifuged once and the supernatant is removed, the lower layer of the precipitate is further centrifuged and washed with ethanol twice.

[0016] Further, the rotation speed of each centrifugation is 3000-3500 rad / min, and the time of each centrifugation is 5-10 min.

[0017] Further, the drying temperature is 90-100℃, and the time is >90 min.

[0018] The application also provides the Mg 2+ mediated Eu-containing amorphous calcium carbonate luminescent nanomaterial prepared by the preparation method.

[0019] Compared with the prior art, the application has the following advantages and technical effects:

[0020] 1. The application realizes the successful preparation of the Eu-containing amorphous calcium carbonate luminescent nanomaterial with controllable rare earth distribution and a rare earth doping concentration of up to 78.3 mol%.

[0021] 2. The Eu-containing amorphous calcium carbonate luminescent nanomaterial synthesized by the application has controllable luminescent performance and excellent brightness, and the preparation process is simple.

[0022] 3. The Eu-containing amorphous calcium carbonate luminescent nanomaterial prepared by the application can be used as a light conversion agent and applied to agricultural plastic films to play the role of a light conversion agent, which is conducive to reducing plant diseases and insect pests, and at the same time, converts ultraviolet light that causes the oxidation and degradation of the agricultural plastic film (polyethylene film) into blue-violet light and red-orange light to promote photosynthesis of plants.

[0023] 4. The application adopts Mg 2+ ​​​The controlled ADM mineralization process fills the technological gap in the field of rare earth element-doped amorphous calcium carbonate nanomaterials, expands the rare earth doping technology process route, and effectively improves the stability of the product and extends its service life.

[0024] 5. This invention not only achieves the introduction of rare earth elements through a simple method, but also, compared with other phosphors prepared by wet methods, the phosphor precursors based on calcium carbonate are mostly amorphous and can emit light without high-temperature calcination. This not only significantly reduces costs but also aligns better with the concept of energy conservation and environmental protection. Furthermore, the industrial preparation technology of calcium carbonate is already quite mature, laying a solid foundation for the large-scale synthesis of luminescent materials. Attached Figure Description

[0025] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0026] Figure 1 Mg prepared in Example 1 2+ XRD pattern of Eu-containing amorphous calcium carbonate luminescent nanomaterials mediated by Eu.

[0027] Figure 2 Mg prepared in Example 2 2+ XRD pattern of Eu-containing amorphous calcium carbonate luminescent nanomaterials mediated by Eu.

[0028] Figure 3 Mg prepared in Example 3 2+ XRD pattern of Eu-containing amorphous calcium carbonate luminescent nanomaterials mediated by Eu.

[0029] Figure 4 XRD pattern of the nanomaterial prepared in Comparative Example 1;

[0030] Figure 5 Mg prepared in Example 3 2+ SEM image of Eu-containing amorphous calcium carbonate luminescent nanomaterials mediated by Eu.

[0031] Figure 6 Mg prepared in Example 3 2+ TEM BF image and HAADF STEM-EDS analysis results of Eu-mediated amorphous calcium carbonate luminescent nanomaterials;

[0032] Figure 7 Mg prepared in Examples 1-3 2+ Luminescence pattern of Eu-containing amorphous calcium carbonate luminescent nanomaterials under 393 nm irradiation;

[0033] Figure 8PL-PLE spectra of the nanomaterials prepared for Examples 1-3 and Comparative Example 1;

[0034] Figure 9 Schematic diagram of the device used for the carbonate mineralization reaction in step (2) for Examples 1-3 and Comparative Example 1. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0036] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0037] The embodiment of the present application provides a kind of Mg 2+ The preparation method of the Eu-containing amorphous calcium carbonate luminescent nanomaterial mediated by Mg 2+ The preparation method of the Eu-containing amorphous calcium carbonate luminescent nanomaterial mediated by Mg

[0038] In a preferred embodiment, the molar concentration ratio of Ca 2+ , Eu 3+ and Mg 2+ in the mineralization mother liquor is 1:1:(1-5). The present application controls the doping concentration of Eu in amorphous calcium carbonate luminescent nanomaterial by controlling the concentration of Mg 2+ , and within the above range, the doping concentration of Eu increases with the increase of the concentration of Mg 2+ .

[0039] In a preferred embodiment, the concentration of Ca 2+ in the mineralization mother liquor is 100 mmol / L, the concentration of Eu 3+ is 100 mmol / L, and the concentration of Mg 2+ is 100-500 mmol / L.

[0040] In a preferred embodiment, the Ca salt is selected from CaCl2; the Eu salt is selected from EuCl3; and the Mg salt is selected from MgCl2.

[0041] In a preferred embodiment, the ratio of the volume of the mineralization mother liquor to the mass of the ammonium carbonate powder is 50:2 (mL / g).

[0042] In a preferred embodiment, the temperature of the carbonate mineralization reaction is 20-30℃, and the reaction time is 11-12h. The present application prevents the transformation of amorphous calcium carbonate into a more stable crystal form by performing the carbonate mineralization reaction at a lower temperature.

[0043] In a preferred embodiment, the centrifugation is performed as follows: the reaction solution obtained after the carbonate mineralization reaction is centrifuged once and the supernatant is removed, and the lower precipitate is further centrifuged twice with ethanol for cleaning and separation.

[0044] In a preferred embodiment, the rotation speed of each centrifugation is 3000-3500 rad / min, and the time of each centrifugation is 5-10 min.

[0045] In a preferred embodiment, the drying temperature is 90-100℃, and the time is >90 min.

[0046] The present application also provides the Mg 2+ containing amorphous calcium carbonate luminescent nanomaterial mediated by Eu

[0047] In the examples and comparative examples below, CaCl2, EuCl3 and MgCl2 are all analytically pure reagents.

[0048] In the examples and comparative examples below, CaCl2, EuCl3 and MgCl2 are all analytically pure reagents.

[0049] Example 1

[0050] The present application also provides the Mg 2+ containing amorphous calcium carbonate luminescent nanomaterial mediated by Eu

[0051] (1) CaCl2, EuCl3 and MgCl2 are used as raw materials to prepare a mineralization mother liquor, and the concentrations of Ca 2+ , Eu 3+ and Mg 2+ in the mineralization mother liquor are 100mM (i.e. the molar ratio of Ca 2+ , Eu 3+ and Mg 2+ in the mineralization mother liquor is 1:1:1);

[0052] (2) Put the beaker containing 50 mL of the mineralization mother liquor and the beaker containing 2 g of ammonium carbonate powder on the multi-magnetic stirrer simultaneously, and carry out the carbonate mineralization reaction under the conditions of stirring, sealing, normal pressure and 25±3℃. (The schematic diagram of the device used for the carbonate mineralization reaction is shown in Figure 1) Figure 9 After 11 h of reaction, the reaction solution is obtained;

[0053] (3) Pour the reaction solution obtained in step (2) into a centrifuge tube, and use a low-speed centrifuge to carry out primary centrifugation. Then, the supernatant is sucked out, and the precipitate is reserved. The obtained precipitate is further centrifuged and separated twice with ethanol. The rotation speed of each centrifugation is 3500 rad / min, and the time length of each centrifugation is 5 min. After centrifugation, the precipitate obtained by centrifugation is placed in a glass culture dish, and is placed in a blast drying oven for drying at 90℃ for 90 min. Mg 2+ Eu-containing amorphous calcium carbonate luminescent nanomaterial mediated by Mg

[0054] The Mg 2+ Eu-containing amorphous calcium carbonate luminescent nanomaterial mediated by Mg Figure 1 of Example 1 is subjected to XRD analysis, and the results are shown in Figure 2. Figure 1 It can be seen from Figure 2 that the crystal form of the nanomaterial obtained in Example 1 is consistent with the characteristics of amorphous calcium carbonate as a whole, and there is a peak value consistent with the <104> crystal face diffraction of calcite PDF standard card (JCPDS: 05-0586), indicating that the nanomaterial as a whole is amorphous calcium carbonate with a trace amount of calcite crystal structure.

[0055] Example 2

[0056] The difference from Example 1 is that in step (1), the concentration of Mg 2+ in the mineralization mother liquor is 200 mM (i.e., the molar concentration ratio of Ca 2+ , Eu 3+ and Mg 2+ in the mineralization mother liquor is 1:1:2), and the others are the same as in Example 1.

[0057] The Mg 2+ Eu-containing amorphous calcium carbonate luminescent nanomaterial mediated by Mg Figure 2 of Example 2 is subjected to XRD analysis, and the results are shown in Figure 4. Figure 2 It can be seen from Figure 4 that the crystal form of the nanomaterial obtained in Example 2 is consistent with the characteristics of amorphous calcium carbonate as a whole, and there is a peak value consistent with the <104> crystal face diffraction of calcite PDF standard card (JCPDS: 05-0586), indicating that the nanomaterial as a whole is amorphous calcium carbonate with a trace amount of calcite crystal structure.

[0058] Example 3

[0059] The difference from Example 1 is that, in step (1), the Mg in the mineralization mother liquor... 2+ The concentration is 500 mM (i.e., Ca in the mineralization mother liquor). 2+ Eu 3+ and Mg 2+ The molar concentration ratio is 1:1:5, and other aspects are the same as in Example 1.

[0060] The Mg prepared in Example 3 2+ XRD analysis was performed on Eu-containing amorphous calcium carbonate luminescent nanomaterials mediated by [the method described in the original text]. The results are shown in [the original text]. Figure 3 .from Figure 3 It can be seen that the overall crystal structure of the nanomaterial obtained in Example 3 conforms to the characteristics of amorphous calcium carbonate.

[0061] Figure 5 Mg prepared in Example 3 2+ SEM images of Eu-containing amorphous calcium carbonate luminescent nanomaterials mediated by [a specific method / mechanism]. Figure 5 It can be seen that the Eu-containing amorphous calcium carbonate luminescent nanomaterial particles prepared in Example 3 are uniform.

[0062] Figure 6 Mg prepared in Example 3 2+ TEM BF image and HAADF STEM-EDS analysis results of Eu-containing amorphous calcium carbonate luminescent nanomaterials mediated by calcium carbonate. From left to right in the image, the images show the TEM BF image, the HAADF STEM-EDS analysis results for Ca, and the HAADF STEM-EDS analysis results for Eu. Figure 6 It can be seen that Eu is uniformly distributed in the nanomaterial.

[0063] Comparative Example 1

[0064] The difference from Example 1 is that step (1) is: a mineralization mother liquor is prepared using CaCl2 and EuCl3 as raw materials, wherein the Ca in the mineralization mother liquor is... 2+ The concentration was 100 mM, Eu 3+ The concentration was 100 mM; other details were the same as in Example 1.

[0065] The nanomaterials prepared in Comparative Example 1 were subjected to XRD analysis, and the results are shown in the figure. Figure 4 By Figure 4 The data in the comparison was compared with the PDF standard card (JCPDS:05-0586) to confirm that the nanomaterial prepared in Comparative Example 1 has a calcite-type crystal structure.

[0066] The nanomaterials prepared in Examples 1-3 and Comparative Example 1 were characterized by ICP-OES to obtain Eu. 3+ The doping levels were determined, and the results are shown in Table 1.

[0067] Table 1. Eu content in the nanomaterials prepared in Examples 1-3 and Comparative Example 1 3+ doping amount

[0068]

[0069] As can be seen from Table 1, in the absence of Mg 2+ In the case of mediation, Eu 3+ The doping amount in calcium carbonate was 49.6 mol%, while the Mg content in the mineralization mother liquor was increased. 2+ Concentration can further enhance Eu 3+ Doping amount in amorphous calcium carbonate nanomaterials.

[0070] Figure 7 Mg prepared in Examples 1-3 2+ A photograph of Eu-containing amorphous calcium carbonate luminescent nanomaterials irradiated at 393 nm. From Figure 7 It can be seen that the nanomaterials prepared in Examples 1-3 can all emit bright red light, among which the nanomaterial prepared in Example 3 emits the brightest red light.

[0071] Figure 8 The PL-PLE spectra of the nanomaterials prepared in Examples 1-3 and Comparative Example 1 are shown. Figure 8 It can be seen that, under the same Eu 3+ At a certain concentration, by increasing the Mg content in the mineralization mother liquor 2+ Concentration can further enhance the luminescent properties of the material.

[0072] Figure 9 This is a schematic diagram of the apparatus used for the carbonate mineralization reaction in step (2) of Examples 1-3 and Comparative Example 1. From... Figure 9 It can be seen that through the ammonium carbonate diffusion method, solid (NH4)2CO3 decomposes into CO2 and NH3. CO2 and NH3 diffuse across the gas-liquid interface into the mother liquor, producing CO32-. 2- CO3 2- With Ca in the mother liquor 2+ The reaction produces calcium carbonate.

[0073] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A Mg 2+ method for preparing a Eu-containing amorphous calcium carbonate luminescent nanomaterial under mediation of Mg The method comprises the following steps: Preparation of a mineralization mother liquor with Ca salt, Eu salt and Mg salt as raw materials; The mineralized mother liquor and ammonium carbonate powder are subjected to a carbonate mineralization reaction by ammonium carbonate diffusion method, and then subjected to centrifugation and drying to obtain the Mg 2+ containing Eu amorphous calcium carbonate luminescent nanomaterials mediated by the enzyme.

2. The production method according to claim 1, characterized by, The ratio of the molar concentrations of Ca 2+ , Eu 3+ and Mg 2+ in the mineralizing mother liquor is 1:1:(1-5).

3. The preparation method according to claim 2, characterized in that, Ca in the mineralized mother liquor 2+ The concentration was 100 mmol / L, Eu 3+ The concentration was 100 mmol / L, Mg 2+ The concentration is 100-500 mmol / L.

4. The method of claim 1, wherein, The Ca salt is selected from CaCl2; and / or, the Eu salt is selected from EuCl3; and / or, the Mg salt is selected from MgCl2.

5. The preparation method according to claim 1, characterized in that, The ratio of the volume of the mineralization mother liquor to the mass of the ammonium carbonate powder is 50 mL:2 g.

6. The method of claim 1, wherein, The temperature of the carbonate mineralization reaction is 20-30 ℃, and the reaction time is 11-12 h.

7. The preparation method according to claim 1, characterized in that, The centrifugation is specifically as follows: the reaction solution obtained after the carbonate mineralization reaction is centrifuged once, and the supernatant is removed; then the lower layer of the precipitate is further centrifuged twice with ethanol for cleaning and separation.

8. The preparation method according to claim 7, characterized in that, The rotation speed of each centrifugation is 3000-3500 rad / min, and the time of each centrifugation is 5-10 min.

9. The method of claim 1, wherein, The drying temperature is 90-100 ℃, and the time is > 90 min.

10. The Mg prepared by the method of any one of claims 1-9 2+ luminescent nanomaterials containing Eu under mediation of amorphous calcium carbonate.

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