Preparation method of ultra-small gadolinium oxide rare earth nanomaterial
Ultra-small and uniform rare earth gadolinium oxide nanomaterials were prepared by heating and high-temperature treatment of gadolinium acetylacetonate and surfactant, which solved the problems of complex process and long cycle in the existing technology and realized the efficient preparation of nanomaterials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI UNIV
- Filing Date
- 2023-06-15
- Publication Date
- 2026-04-21
AI Technical Summary
Existing technologies for preparing Gd2O3 nanoparticles involve complex processes, demanding equipment, and long synthesis cycles, and the nanomaterials exhibit uneven particle size and poor dispersibility.
Ultra-small and uniform rare earth gadolinium oxide nanomaterials were prepared by mixing and heating an aqueous solution of gadolinium acetylacetonate with a surfactant, followed by high-temperature treatment under a protective atmosphere and washing and centrifugation.
It achieves a simple process, low equipment requirements, short synthesis cycle, uniform particle size and good dispersibility of nanomaterials, and is suitable for magnetic resonance imaging contrast agents.
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Figure CN116789160B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of functional materials technology, specifically to a method for preparing ultra-small rare earth gadolinium oxide nanomaterials. Background Technology
[0002] Compared with traditional nanomaterials such as organic dyes and quantum dots, rare-earth luminescent nanomaterials have many advantages, such as large anti-Stokes shift, high chemical stability, long fluorescence lifetime, low background noise, and low toxicity. This has led to their widespread application in lighting displays, 3D imaging, information anti-counterfeiting, biomedicine, and environmental remediation. Gadolinium is one of the important rare-earth elements, and gadolinium-based rare-earth elements, due to their excellent and unique properties, have been widely used in optical, electronic, and magnetic materials. As a rare-earth element, gadolinium has the widest range of applications among all the new rare-earth materials currently being researched, and it will play a crucial role in the modern technological revolution. With the development and application of rare-earth elements, there are many types of luminescent matrix materials. Among them, Gd₂O₃ (gadolinium oxide) has low phonon energy and is easy to dope with other rare-earth luminescent ions (such as Tm). 3+ Er 3+ Yb 3+ Gadolinium oxide (Gd₂O₃) possesses advantages such as minimal absorption of excitation light, good physicochemical stability, and high near-infrared light transmittance, making it an excellent host matrix material for up / down conversion fluorescence. Furthermore, Gd₂O₃ is the most typical and widely used gadolinium-based rare earth material. It is used in the manufacture of X-ray intensifying screens and capacitors; gadolinium oxide is also used as a control material in boiling water nuclear reactors. Gadolinium can be used as an additive in magnets, ensuring that the magnet's performance remains unchanged with temperature. In conclusion, with the research and development of gadolinium oxide, it can be widely applied in many more fields.
[0003] Because the size, morphology, and structure of nanomaterials have a significant impact on their physicochemical properties, they have attracted widespread attention from the academic community. Among them, uniformly sized, monodisperse rare-earth luminescent nanomaterials have received extensive research due to their promising applications in medical diagnosis and treatment. To date, various rare-earth luminescent nanomaterials have been synthesized using different methods, such as electrochemical methods, microemulsion coupling methods, homogeneous precipitation methods, and hydrothermal methods. However, these methods suffer from drawbacks in preparing Gd₂O₃ nanoparticles, including complex processes, demanding equipment requirements, and long synthesis cycles. Summary of the Invention
[0004] To address the problems of existing technologies, the present invention aims to overcome the shortcomings of existing technologies and provide a method for preparing ultra-small rare earth gadolinium oxide nanomaterials. This method features a simple process flow, easily controllable reaction conditions, mild reaction conditions, good process repeatability, low equipment requirements, and a short synthesis cycle. Furthermore, the synthesized nanomaterials have the characteristics of ultra-small particle size, uniform size distribution, good dispersibility, and high yield. The ultra-small functionalized gadolinium oxide rare earth nanoparticles prepared by this method, due to the advantages of nanosize effect, good dispersibility, stability, and high relaxation rate, can significantly shorten the longitudinal relaxation time of water molecules and can be used as an excellent magnetic resonance imaging contrast agent.
[0005] To achieve the above objectives, the specific technical solution of the present invention is as follows:
[0006] A method for preparing ultra-small rare-earth gadolinium oxide nanomaterials includes the following steps:
[0007] S1, Precursors for preparing rare earth salts
[0008] A first part of a mixed solvent of surfactant and octadecene is added to an aqueous solution containing gadolinium acetylacetonate (III) to obtain a mixed solution. The mixed solution is subjected to a first heating reaction until the water in the mixed solution is completely removed, and then the first heating reaction is terminated to obtain the precursor of the rare earth salt.
[0009] S2, reaction solution for synthesizing gadolinium oxide nanomaterials
[0010] A second part of surfactant is added to the rare earth salt precursor, and after mixing and stirring, it is fully dissolved to obtain a mixed solution. The mixed solution is placed in a protective atmosphere for a second heating reaction to obtain a high-temperature gadolinium oxide nanomaterial reaction solution. After the second heating reaction is completed, the heating is stopped, and the high-temperature gadolinium oxide nanomaterial reaction solution is placed in a protective atmosphere and cooled to room temperature to obtain the gadolinium oxide nanomaterial reaction solution.
[0011] Washing of S3, gadolinium oxide nanomaterials
[0012] The gadolinium oxide nanomaterials were washed in a polar solvent, and then the precipitate was collected by centrifugation to obtain gadolinium oxide nanomaterials.
[0013] Preferably, the solvent in the aqueous solution containing gadolinium acetylacetonate (III) is water, and the solute is an aqueous solution of gadolinium acetylacetonate (III).
[0014] Preferably, the aqueous solution containing gadolinium acetylacetonate (III) further includes ytterbium ions and thulium ions.
[0015] Preferably, the temperature of the first heating reaction is 150°C.
[0016] Preferably, the first surfactant is oleylamine and oleic acid in a volume ratio of 1:1, and the second surfactant is 1,2-dodecanediol.
[0017] Preferably, the protective atmosphere is nitrogen or argon.
[0018] Preferably, the parameters for the second heating reaction are: heating rate of 50℃ / min, temperature of 300℃, and holding time of at least 2 hours.
[0019] Preferably, the polar solvent is a mixture of ethanol and cyclohexane in a volume ratio of 3:2, and the ethanol is anhydrous ethanol.
[0020] Preferably, the washing and centrifugation processes are repeated three or more times.
[0021] Preferably, the gadolinium oxide nanomaterial is stored in cyclohexane at a storage temperature of 0~4℃.
[0022] Compared with the prior art, the beneficial effects of the present invention are:
[0023] The present invention proposes a method for preparing ultra-small rare earth gadolinium oxide nanomaterials, which has a milder reaction temperature than existing methods, is simple to operate, has a shorter reaction time, and is conducive to energy saving;
[0024] The present invention proposes a method for preparing ultra-small rare earth gadolinium oxide nanomaterials. The equipment is simple, the process is highly reproducible, the product quality is stable, and it has broad application prospects.
[0025] This invention proposes a method for preparing ultra-small rare earth gadolinium oxide nanomaterials, which produces rare earth gadolinium oxide nanoparticles with uniform particle size, good dispersibility, and ultra-small size.
[0026] This invention proposes a method for preparing ultra-small rare earth gadolinium oxide nanomaterials. The method uses rare earth ion doping to control the particle size of gadolinium oxide nanoparticles. The reaction conditions of this method are easy to control, and the type and amount of rare earth ion doping can be appropriately selected according to actual conditions and needs.
[0027] The present invention proposes a method for preparing ultra-small rare earth gadolinium oxide nanomaterials, which achieves slight agglomeration of gadolinium oxide nanoparticles by adjusting the amount of surfactant used. Attached Figure Description
[0028] Figure 1 The image shown is a transmission electron microscope (TEM) image of rare earth gadolinium oxide nanoparticles prepared in Example 1 of this invention. The inset is a particle size distribution diagram.
[0029] Figure 2The ytterbium ion (Yb) doped in Example 2 of this invention 3+ ) and thulium ions (Tm 3+ Transmission electron microscopy (TEM) images of rare earth gadolinium oxide nanoparticles, with the inset showing the particle size distribution.
[0030] Figure 3 The image shown is a transmission electron microscope (TEM) image of rare earth gadolinium oxide nanoparticles synthesized after adjusting the ratio of oleylamine and oleic acid in Example 3 of this invention. The scale bar is 0.1 μm, and the inset is a TEM image with a scale bar of 50 nm.
[0031] Figure 4 Transmission electron microscopy (TEM) image of rare earth gadolinium oxide nanoparticles synthesized after adjusting the amount of 1,2-dodecanediol in Example 4 of this invention. Detailed Implementation
[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0033] To facilitate understanding, the English terms mentioned below will be explained first:
[0034] M: Abbreviation for volumetric molar concentration in mol / L.
[0035] Example 1:
[0036] S1, Precursors for preparing rare earth salts
[0037] Add 1 mL of oleic acid, 1 mL of oleylamine and 10 mL of octadecene to 2 mL of a 0.2 M aqueous solution containing gadolinium acetylacetonate (III) to obtain a mixed solution. The mixed solution is subjected to a first heating reaction at 150 °C until the water in the mixed solution is completely removed, and then the first heating reaction is stopped to allow the rare earth ions to be completely dissolved in the mixed organic solution, thereby obtaining the precursor of the rare earth salt.
[0038] S2, reaction solution for synthesizing gadolinium oxide nanomaterials
[0039] At room temperature, 1g of surfactant 1,2-dodecanediol is added to the rare earth salt precursor. After mixing and stirring until fully dissolved, a mixed solution is obtained. The mixed solution is then placed under a protective atmosphere for a second heating reaction, with the temperature increased to 300°C at a rate of 50°C / min and held for 2 hours to obtain a high-temperature gadolinium oxide nanomaterial reaction solution. After the second heating reaction is completed, heating is stopped, and the high-temperature gadolinium oxide nanomaterial reaction solution is cooled to room temperature under a protective atmosphere to obtain the gadolinium oxide nanomaterial reaction solution.
[0040] Washing of S3, gadolinium oxide nanomaterials
[0041] The cooled gadolinium oxide nanomaterials were washed in a polar solvent, and then the precipitate was collected by centrifugation. The washing and centrifugation were repeated three times to obtain gadolinium oxide nanomaterials.
[0042] The gadolinium oxide nanomaterials prepared in this embodiment are as follows: Figure 1 As shown, the gadolinium oxide nanoparticles are spherical, uniformly sized, and well dispersed, with a particle size of 2-3 nm.
[0043] The gadolinium oxide nanomaterials prepared in this embodiment are suitable for storage in 4 mL of cyclohexane.
[0044] Example 2:
[0045] S1, Precursors for preparing rare earth salts
[0046] A mixture of 1.6 mL of a 0.2 M aqueous solution containing gadolinium acetylacetonate (III), 0.38 mL of a 0.2 M aqueous solution containing ytterbium acetylacetonate (III), and 0.02 mL of a 0.2 M aqueous solution containing thulium trichloride (III) was prepared to contain gadolinium acetylacetonate (III). A mixed solvent of 1 mL oleic acid, 1 mL oleylamine, and 10 mL octadecene was added to the gadolinium acetylacetonate (III) aqueous solution to obtain a mixed solution. The mixed solution was subjected to a first heating reaction at 150 °C until the water in the mixed solution was completely removed, thereby completely dissolving the rare earth ions in the mixed organic solution to obtain the precursor of the rare earth salt.
[0047] S2, reaction solution for synthesizing gadolinium oxide nanomaterials
[0048] At room temperature, 1g of surfactant 1,2-dodecanediol was added to the rare earth salt precursor. After mixing and stirring until fully dissolved, a mixed solution was obtained. The mixed solution was then placed under a high-purity argon protective atmosphere for a second heating reaction, with the temperature increased to 300°C at a rate of 50°C / min and held for 2 hours to obtain a high-temperature gadolinium oxide nanomaterial reaction solution. After the second heating reaction was completed, heating was stopped, and the high-temperature gadolinium oxide nanomaterial reaction solution was placed under a high-purity argon protective atmosphere and cooled to room temperature to obtain the gadolinium oxide nanomaterial reaction solution.
[0049] Washing of S3, gadolinium oxide nanomaterials
[0050] The cooled gadolinium oxide nanomaterials were washed in a polar solvent, and then the precipitate was collected by centrifugation. The washing and centrifugation were repeated three times to obtain gadolinium oxide nanomaterials.
[0051] The gadolinium oxide nanomaterials prepared in this embodiment are as follows: Figure 2 As shown, the gadolinium oxide nanoparticles are spherical, uniformly sized, and well-dispersed, with a particle size of 8-9 nm. The gadolinium oxide nanomaterials prepared in this example are suitable for storage in 4 mL of cyclohexane.
[0052] It should be noted that in this embodiment, ytterbium acetylacetonate (III) and thulium trichloride (III) are used for doping ytterbium ions and thulium ions. In actual implementation, other water-soluble substances can be used instead.
[0053] Example 3:
[0054] S1, Precursors for preparing rare earth salts
[0055] Add 300 μL of oleic acid, 300 μL of oleylamine and 10 mL of octadecene to 2 mL of a 0.2 M aqueous solution containing gadolinium acetylacetonate (III) to obtain a mixed solution. The mixed solution is then subjected to a first heating reaction at 150 °C until the water in the mixed solution is completely removed, thereby completely dissolving the rare earth ions in the mixed organic solution to obtain the precursor of the rare earth salt.
[0056] S2, reaction solution for synthesizing gadolinium oxide nanomaterials
[0057] At room temperature, 1g of surfactant 1,2-dodecanediol was added to the rare earth salt precursor. After mixing and stirring until fully dissolved, a mixed solution was obtained. The mixed solution was then placed under a high-purity argon protective atmosphere for a second heating reaction, with the temperature increased to 300°C at a rate of 50°C / min and held for 2 hours to obtain a high-temperature gadolinium oxide nanomaterial reaction solution. After the second heating reaction was completed, heating was stopped, and the high-temperature gadolinium oxide nanomaterial reaction solution was placed under a high-purity argon protective atmosphere and cooled to room temperature to obtain the gadolinium oxide nanomaterial reaction solution.
[0058] Washing of S3, gadolinium oxide nanomaterials
[0059] The cooled gadolinium oxide nanomaterials were washed in a polar solvent, and then the precipitate was collected by centrifugation. The washing and centrifugation were repeated three times to obtain gadolinium oxide nanomaterials.
[0060] The gadolinium oxide nanomaterials prepared in this embodiment are as follows: Figure 3 As shown, the gadolinium oxide nanoparticles are spherical, uniform in size distribution, and well dispersed. Reducing the amount of oleylamine and oleic acid used will cause the gadolinium oxide nanoparticles to slightly agglomerate, but the particle size will not change significantly compared with the gadolinium oxide nanomaterials prepared in Example 2.
[0061] The gadolinium oxide nanomaterials prepared in this embodiment are suitable for storage in 4 mL of cyclohexane.
[0062] Example 4:
[0063] S1, Precursors for preparing rare earth salts
[0064] Add 1 mL of oleic acid, 1 mL of oleylamine and 10 mL of octadecene to 2 mL of a 0.2 M aqueous solution containing gadolinium acetylacetonate (III) to obtain a mixed solution. The mixed solution is subjected to a first heating reaction at 150 °C until the water in the mixed solution is completely removed, and then the first heating reaction is stopped to allow the rare earth ions to be completely dissolved in the mixed organic solution, thereby obtaining the precursor of the rare earth salt.
[0065] S2, reaction solution for synthesizing gadolinium oxide nanomaterials
[0066] At room temperature, 311 mg of surfactant 1,2-dodecanediol was added to the rare earth salt precursor. After mixing and stirring until fully dissolved, a mixed solution was obtained. The mixed solution was then placed under a high-purity argon protective atmosphere for a second heating reaction, with the temperature increased to 300°C at a rate of 50°C / min and held for 2 hours to obtain a high-temperature gadolinium oxide nanomaterial reaction solution. After the second heating reaction was completed, heating was stopped, and the high-temperature gadolinium oxide nanomaterial reaction solution was cooled to room temperature under a high-purity argon protective atmosphere to obtain the gadolinium oxide nanomaterial reaction solution.
[0067] Washing of S3, gadolinium oxide nanomaterials
[0068] The cooled gadolinium oxide nanomaterials were washed in a polar solvent, and then the precipitate was collected by centrifugation. The washing and centrifugation were repeated three times to obtain gadolinium oxide nanomaterials.
[0069] The gadolinium oxide nanomaterials prepared in this embodiment are as follows: Figure 4 As shown, gadolinium oxide nanoparticles slightly aggregate, and after aggregation, they are distributed in a cloud-like pattern.
[0070] The gadolinium oxide nanomaterials prepared in this embodiment are suitable for storage in 4 mL of cyclohexane.
[0071] It should be noted that in Examples 1 to 4 above, the polar solvent was anhydrous ethanol and cyclohexane in a volume ratio of 3:2. Of course, in actual implementation, other polar organic compounds, such as acetone, can also be used for preparation.
[0072] It should be noted that the mixing and stirring used in Examples 1 to 4 above can be magnetic stirring, mechanical stirring or ultrasonic vibration, so that the metal oxide is uniformly dispersed in the solvent.
[0073] It should be noted that the protective atmosphere of the high-purity argon used in Examples 1 to 4 above can also be replaced with a high-purity argon protective atmosphere.
[0074] It should be noted that in Examples 1 to 4 above, the various reagents used in the reaction solution for synthesizing gadolinium oxide nanomaterials are chemically pure, such as oleylamine, oleic acid, or 1,2-dodecanediol; the various reagents used for washing and preserving gadolinium oxide nanomaterials are analytically pure, such as ethanol and cyclohexane.
[0075] In summary, the ultra-small rare earth gadolinium oxide nanoparticles prepared in Examples 1 to 4 have good dispersibility, uniform particle size, and can easily enter biological bodies for some magnetic resonance imaging applications.
[0076] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended embodiments and their equivalents.
Claims
1. A method for preparing ultra-small gadolinium oxide rare earth nanomaterials, characterized in that, A method for preparing ultra-small rare-earth gadolinium oxide nanomaterials includes the following steps: S1, Precursors for preparing rare earth salts A first part of a mixed solvent of surfactant and octadecene is added to an aqueous solution containing gadolinium acetylacetonate to obtain a mixed solution. The mixed solution is subjected to a first heating reaction until the water in the mixed solution is completely removed, and then the first heating reaction is ended to obtain the precursor of the rare earth salt. The first surfactant is oleylamine and oleic acid in a volume ratio of 1:1; The temperature of the first heating reaction is 150°C; S2, reaction solution for synthesizing gadolinium oxide nanomaterials A second part of surfactant is added to the rare earth salt precursor, and after mixing and stirring, it is fully dissolved to obtain a mixed solution. The mixed solution is placed in a protective atmosphere for a second heating reaction to obtain a high-temperature gadolinium oxide nanomaterial reaction solution. After the second heating reaction is completed, the heating is stopped, and the high-temperature gadolinium oxide nanomaterial reaction solution is placed in a protective atmosphere and cooled to room temperature to obtain the gadolinium oxide nanomaterial reaction solution. The second surfactant is 1,2-dodecanediol; The parameters for the second heating reaction are: heating rate of 50℃ / min, temperature of 300℃, and holding time of at least 2 hours; Washing of S3, gadolinium oxide nanomaterials The gadolinium oxide nanomaterials were washed in a polar solvent, and then the precipitate was collected by centrifugation to obtain gadolinium oxide nanomaterials.
2. The method for preparing ultra-small rare earth gadolinium oxide nanomaterials according to claim 1, characterized in that, The aqueous solution containing gadolinium acetylacetonate is an aqueous solution in which water is the solvent and gadolinium acetylacetonate is the solute.
3. The method for preparing ultra-small rare earth gadolinium oxide nanomaterials according to claim 2, characterized in that, The aqueous solution containing gadolinium acetylacetonate also includes ytterbium ions and thulium ions.
4. The method for preparing ultra-small rare earth gadolinium oxide nanomaterials according to claim 1, characterized in that, The protective atmosphere is nitrogen or argon.
5. The method for preparing ultra-small rare earth gadolinium oxide nanomaterials according to claim 1, characterized in that, The polar solvent is a mixture of ethanol and cyclohexane in a 3:2 ratio, and the ethanol is anhydrous ethanol.
6. The method for preparing ultra-small rare earth gadolinium oxide nanomaterials according to claim 1, characterized in that, The washing and centrifugation processes are repeated at least three times.
7. The method according to any one of claims 1 to 6, wherein the method is characterized by, The gadolinium oxide nanomaterials are stored in cyclohexane at a temperature of 0-4°C.