Thorium polymer spun fiber precursor, thorium oxide nanofiber and preparation method and application
By preparing thorium polymer spinning precursors and employing electrospinning and heat treatment processes, the problem of thorium oxide nanofiber preparation was solved, and efficient preparation of thorium oxide nanofibers suitable for neutron shielding materials and propagation nuclear fuels was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NUCLEAR POWER INSTITUTE OF CHINA
- Filing Date
- 2023-11-10
- Publication Date
- 2026-06-30
AI Technical Summary
Existing technologies are insufficient for the effective preparation of thorium oxide nanofibers, limiting their application in neutron shielding materials and breederable nuclear fuels.
Thorium oxide nanofibers were prepared by using electrospinning and heat treatment processes after the preparation of thorium polymer spinning precursors.
The prepared thorium oxide nanofibers have uniform diameter, dense structure, and good flexibility, making them suitable for neutron shielding materials and propagation nuclear fuels. The process is simple and the raw materials are economical.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention relates to the field of nuclear materials technology, specifically to thorium polymer spinning precursors, thorium oxide nanofibers, their preparation methods, and applications. Background Technology
[0002] Thorium oxide possesses advantages such as a high melting point, single-phase nature, and high refractive index, making it suitable for the preparation of high-temperature ceramics, refractory materials, and special optical glasses. Meanwhile, thorium-232, the most abundant natural thorium, is a high-performance convertible nuclide with a high thermal neutron absorption cross-section. Therefore, thorium oxide can also be used as a neutron shielding material or a breeder fuel in the field of nuclear technology.
[0003] Current research on thorium oxide materials mainly focuses on bulk materials and nanoparticles. Compared with traditional bulk materials or nanopowders, thorium oxide nanofibers have a stable structure, are lightweight, and have good flexibility, resulting in better secondary processing performance. They can be combined with other materials to form more composite material design schemes, expanding the application of thorium oxide materials and thorium resources. Therefore, the preparation of thorium oxide nanofibers has become a major current research direction. Summary of the Invention
[0004] The purpose of this invention is to provide thorium polymer spinning precursors, thorium oxide nanofibers, preparation methods, and applications, thereby solving the problem of thorium oxide nanofiber preparation.
[0005] This invention is achieved through the following technical solution:
[0006] This invention provides a method for preparing a thorium polymer spinning precursor, comprising:
[0007] Thorium chloride powder was dissolved in methanol, and acetylacetone and triethylamine were added and stirred thoroughly to obtain a thorium-containing polymer solution.
[0008] The thorium-containing polymer solution was concentrated under reduced pressure to obtain a white agglomerate or crystalline powder. A first solvent was added to the white agglomerate or crystalline powder, and the soluble matter was dissolved by stirring and then allowed to stand and filtered. The solution was concentrated under reduced pressure again to obtain a white powder, which is the thorium polymer fiber precursor.
[0009] Furthermore, in the method for preparing the thorium polymer fiber-spinning precursor, 100g of thorium chloride powder is dissolved in 500mL~2000mL of methanol;
[0010] Preferably, the molar ratio of added thorium chloride, acetylacetone, and triethylamine is 1:(0.8~3):(3~5);
[0011] Preferably, the stirring reaction time of thorium chloride, acetylacetone and triethylamine is 0.5h to 3h.
[0012] Furthermore, in the method for preparing the thorium polymer fiber precursor, the temperature for vacuum concentration is 30°C to 60°C.
[0013] Preferably, 100g of white agglomerate or crystalline powder is dissolved in 200mL~1000mL of the first solvent;
[0014] Preferably, the first solvent includes one or more of acetone and tetrahydrofuran;
[0015] Preferably, the first solvent is added to the white agglomerated material or crystalline powder, stirred for 0.5 h to 3 h until the soluble substance is dissolved, and then filtered after standing for 1 to 48 h.
[0016] Furthermore, in the method for preparing the thorium polymer spinning precursor, the preparation of the thorium chloride powder includes:
[0017] Thorium nitrate hexahydrate was dissolved in a second solvent and stirred until the solution was clear. Ammonia was then added and stirring continued to form a white precipitate. The white precipitate was filtered out and repeatedly washed with the second solvent. The filtered white precipitate was evenly dispersed in the second solvent, and hydrochloric acid was added dropwise to the solution to completely dissolve the precipitate. The resulting solution was concentrated, evaporated to dryness, and ground to obtain the thorium chloride powder.
[0018] Furthermore, in the method for preparing the thorium polymer fiber-spinning precursor, the second solvent includes one or two of water, methanol, and ethanol.
[0019] Preferably, ammonia is added at a molar ratio of thorium nitrate to ammonia of 1:(3~6);
[0020] Preferably, hydrochloric acid is added at a molar ratio of thorium nitrate to hydrochloric acid of 1:(3~6);
[0021] Preferably, the white precipitate is repeatedly rinsed with a second solvent until the conductivity of the filtrate is less than 500 μS / cm.
[0022] The present invention also provides a thorium polymer spinning precursor prepared by the above-described method.
[0023] The present invention also provides a method for preparing thorium oxide nanofibers comprising the above-mentioned thorium polymer spinning precursor, comprising:
[0024] Thorium polymer spinning precursor, methanol and polyethylene oxide are mixed to prepare a spinning solution;
[0025] Under high voltage static electricity, electrospinning is used to spin the spinning solution into thorium polymer fiber precursor nanofibers.
[0026] The thorium polymer spinning precursor nanofibers are heat-treated in a heat treatment atmosphere to obtain the thorium oxide nanofibers.
[0027] Furthermore, in the method for preparing thorium oxide nanofibers, the mass ratio of the added thorium polymer spinning precursor, methanol, and polyethylene oxide is (50~300):(200~900):1;
[0028] Preferably, in the spinning process, the electrospinning voltage is 3kV~20kV, and the spinning solution speed is 0.3mL / h~2mL / h;
[0029] Preferably, in the spinning process, the spinning temperature is 20℃~40℃, and the spinning humidity is 15%~45%;
[0030] Preferably, in the spinning process, the take-up distance is 5cm to 30cm;
[0031] Preferably, in the heat treatment process, the heat treatment atmosphere is nitrogen, argon, or air;
[0032] Preferably, in the heat treatment process, the heat treatment process is as follows: the temperature is increased to 600℃~1200℃ at a rate of 0.5℃ / min~10℃ / min, held for 1h~5h, and then cooled in the furnace.
[0033] The present invention also provides thorium oxide nanofibers prepared by the above-described method.
[0034] The present invention also provides the application of the above-mentioned thorium oxide nanofibers in neutron shielding materials or propagation nuclear fuels.
[0035] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0036] The thorium polymer spinning precursor prepared by this invention requires relatively economical raw materials and has a simple preparation process. Furthermore, it exhibits high thorium content and stable properties, resulting in good filamentation properties in the prepared spinning solution. The prepared thorium oxide fibers have uniform diameter, dense structure, and excellent flexibility. This thorium oxide nanofiber material can be used as a neutron shielding material, a breeder fuel for nuclear technology, and also as a high-temperature resistant material for the preparation of special ceramics. Attached Figure Description
[0037] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:
[0038] Figure 1 This is a sample image of the thorium polymer fiber-spinning precursor obtained in Example 1 of the present invention;
[0039] Figure 2 This is a sample image of the thorium polymer spinning precursor spinning solution obtained in Example 1 of the present invention;
[0040] Figure 3 A macroscopic photograph (1) of thorium oxide nanofibers obtained in Example 1 of the present invention;
[0041] Figure 4 This is a macroscopic photograph (2) of thorium oxide nanofibers obtained in Example 1 of the present invention;
[0042] Figure 5 This is a microscopic image of thorium oxide nanofibers obtained in Example 1 of the present invention;
[0043] Figure 6 The image shows the XRD pattern of thorium oxide nanofibers obtained in Example 1 of this invention. Detailed Implementation
[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are for explanation only and are not intended to limit the invention. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.
[0045] The technical solution of this invention is as follows:
[0046] A method for preparing a thorium polymer fiber-spinning precursor, comprising:
[0047] Thorium chloride powder was dissolved in methanol, and acetylacetone and triethylamine were added and stirred thoroughly to obtain a thorium-containing polymer solution.
[0048] The thorium-containing polymer solution was concentrated under reduced pressure to obtain a white agglomerate or crystalline powder. A first solvent was added to the white agglomerate or crystalline powder, and the soluble matter was dissolved by stirring and then allowed to stand and filtered. The solution was concentrated under reduced pressure again to obtain a white powder, which is the thorium polymer fiber precursor.
[0049] Furthermore, each 100g of thorium chloride powder is dissolved in 500mL to 2000mL of methanol; specifically, each 100g of thorium chloride powder is dissolved in 500mL, 1000mL, 1500mL, or 2000mL of methanol, etc.
[0050] Preferably, the molar ratio of added thorium chloride, acetylacetone, and triethylamine is 1:(0.8~3):(3~5); the molar ratio of added thorium chloride, acetylacetone, and triethylamine can be 1:0.8:3, 1:1:3, 1:1:4, 1:1.5:3.5, 1:2:5, 1:2.5:4, or 1:3:5, etc.
[0051] Preferably, the stirring reaction time of thorium chloride, acetylacetone and triethylamine is 0.5h to 3h, specifically, the stirring reaction time is 0.5h, 1h, 1.5h, 2h, 2.5h or 3h, etc.
[0052] Furthermore, the temperature for vacuum concentration is 30℃~60℃, specifically, the temperature can be 30℃, 35℃, 40℃, 45℃, 50℃, 55℃ or 60℃, etc.
[0053] Preferably, 100g of white agglomerate or crystalline powder is dissolved in 200mL to 1000mL of a first solvent, specifically, 100g of white agglomerate or crystalline powder is dissolved in 200mL, 400mL, 500mL, 600mL, 800mL or 1000mL of a first solvent, etc.
[0054] Preferably, the first solvent includes one or more of acetone and tetrahydrofuran;
[0055] Preferably, a first solvent is added to the white agglomerated material or crystalline powder, and the mixture is stirred for 0.5 h to 3 h until the soluble substance dissolves. Specifically, the stirring time can be 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, or 3 h, etc. After standing for 1 to 48 h, the mixture is filtered. The standing time can be 1 h, 5 h, 10 h, 12 h, 15 h, 20 h, 25 h, 30 h, 35 h, 40 h, 45 h, or 48 h, etc.
[0056] Furthermore, the preparation of the thorium chloride powder includes:
[0057] Thorium nitrate hexahydrate was dissolved in a second solvent and stirred until the solution was clear. Ammonia was then added and stirring continued to form a white precipitate. The white precipitate was filtered out and repeatedly washed with the second solvent. The filtered white precipitate was evenly dispersed in the second solvent, and hydrochloric acid was added dropwise to the solution to completely dissolve the precipitate. The resulting solution was concentrated, evaporated to dryness, and ground to obtain the thorium chloride powder.
[0058] Furthermore, the second solvent includes one or two of water, methanol, and ethanol;
[0059] Preferably, ammonia is added at a molar ratio of thorium nitrate to ammonia of 1:(3~6). Specifically, the molar ratio can be 1:3, 1:4, 1:5 or 1:6, etc.
[0060] Preferably, hydrochloric acid is added at a molar ratio of thorium nitrate to hydrochloric acid of 1:(3~6). Specifically, the molar ratio can be 1:3, 1:4, 1:5 or 1:6, etc.
[0061] Preferably, the white precipitate is repeatedly rinsed with a second solvent until the conductivity of the filtrate is less than 500 μS / cm.
[0062] A method for preparing thorium oxide nanofibers, comprising:
[0063] Thorium polymer spinning precursor, methanol and polyethylene oxide are mixed to prepare a spinning solution;
[0064] Under high voltage static electricity, electrospinning is used to spin the spinning solution into thorium polymer fiber precursor nanofibers.
[0065] The thorium polymer spinning precursor nanofibers are heat-treated in a heat treatment atmosphere to obtain the thorium oxide nanofibers.
[0066] Furthermore, the mass ratio of the added thorium polymer fiber-spinning precursor, methanol, and polyethylene oxide is (50~300):(200~900):1. Specifically, this mass ratio can be 50:200:1, 100:300:1, 150:400:1, 200:500:1, 230:600:1, 250:700:1, 280:800:1, or 300:900:1, etc.
[0067] Preferably, in the spinning process, the electrospinning voltage is 3kV~20kV, specifically, the voltage can be 3 kV, 5kV, 8 kV, 10 kV, 12 kV, 15 kV, 18 kV or 20 kV, etc.; the spinning solution speed is 0.3mL / h~2mL / h, the speed can be 0.3mL / h, 0.5mL / h, 0.7mL / h, 1.0mL / h, 1.3mL / h, 1.5mL / h, 1.7mL / h or 2mL / h, etc.
[0068] Preferably, in the spinning process, the spinning temperature is 20℃~40℃, specifically, the temperature can be 20℃, 22℃, 25℃, 27℃, 30℃, 32℃, 35℃, 37℃ or 40℃, etc.; the spinning humidity is 15%~45%, specifically, the humidity can be 15%, 20%, 25%, 30%, 35% or 40%, etc.
[0069] Preferably, in the spinning process, the take-up distance is 5cm to 30cm. Specifically, this distance can be 5cm, 10cm, 15cm, 20cm, 25cm, or 30cm, etc.
[0070] Preferably, in the heat treatment process, the heat treatment atmosphere is nitrogen, argon, or air;
[0071] Preferably, in the heat treatment process, the heat treatment process is as follows: heating to 600℃~1200℃ at a rate of 0.5℃ / min~10℃ / min, holding at that temperature for 1h~5h, and then cooling in the furnace. Specifically, the heating rate can be 0.5℃ / min, 1℃ / min, 3℃ / min, 5℃ / min, 6℃ / min, 7℃ / min, 8℃ / min, 9℃ / min, or 10℃ / min, etc.; heating to 600℃, 650℃, 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, 1000℃, 1050℃, 1100℃, 1150℃, or 1200℃, etc.; and the holding time can be 1h, 2h, 3h, 4h, or 5h.
[0072] Example 1: The preparation of thorium oxide nanofibers provided in this example includes:
[0073] (1) Weigh 60g of thorium nitrate hexahydrate crystals and dissolve them in deionized water. Stir until the solution is clear. Add 0.5mol of ammonia water and stir to form a white precipitate. Filter the white precipitate and rinse it repeatedly with deionized water until the conductivity of the filtrate is 300μS / cm. Disperse the filtered precipitate in 500ml of methanol and add 0.5mol of hydrochloric acid to the solution to dissolve the precipitate. After the solution is concentrated, dried and ground, thorium chloride powder is obtained.
[0074] (2) Weigh 40g of thorium chloride powder obtained in step (1), dissolve it in 500ml of methanol, add 10g of acetylacetone and 40g of triethylamine, stir thoroughly for 1 hour to obtain a thorium-containing polymer solution.
[0075] (3) The thorium-containing polymer solution obtained in step (2) is concentrated under reduced pressure at 35°C until a white agglomerate or crystalline powder is formed. 350 ml of acetone is added to the powder, stirred and dissolved for 1 h, and then allowed to stand for 10 h. The filtrate is obtained by filtration and concentrated again under reduced pressure at 35°C until a white powder, i.e., the thorium polymer fiber precursor, is formed. Figure 1 Image of the obtained thorium polymer fiber precursor sample.
[0076] (4) Weigh 3g of the thorium polymer obtained in step (3), add it to 10g of methanol solvent, and then add 0.03g of polyethylene oxide (PEO) to obtain a transparent and clear thorium polymer spinning solution. Figure 2 The spinning solution for the obtained thorium polymer spinning precursor;
[0077] (5) Using the spinning solution prepared in step (4) as raw material, electrospinning is carried out to obtain thorium polymer spinning precursor nanofibers. The electrospinning voltage is 10KV, the spinning solution propulsion speed is 1ml / h, the spinning temperature is 30℃, the spinning humidity is 30%, and the take-up distance is 20cm.
[0078] (6) The thorium polymer nanofibers obtained in step (5) are heated to 850°C in air at a heating rate of 2°C / min and kept at that temperature for 3 hours to obtain thorium oxide nanofibers.
[0079] Figure 3 , 4 Macroscopic images of thorium oxide nanofibers were obtained. Figure 5 The obtained microscopic images of thorium oxide nanofibers, Figure 6 The XRD pattern of the thorium oxide nanofibers obtained in this embodiment shows that the thorium oxide nanofibers have a smooth surface, a complete and dense structure, and good flexibility.
[0080] Example 2: The preparation of thorium oxide nanofibers provided in this example differs from that in Example 1 in that the thorium chloride used in step (2) is commercially available thorium tetrachloride.
[0081] The thorium oxide nanofibers obtained in this embodiment are the same as those in Example 1, indicating that the thorium chloride prepared by the present invention can fully meet the quality required for commercial purchase.
[0082] Example 3: The preparation of thorium oxide nanofibers provided in this example differs from that in Example 1 in that:
[0083] In step (1), anhydrous ethanol was used as the solvent. Ammonia was added at a molar ratio of ammonia to thorium nitrate of 5:1 to obtain a white precipitate. After filtration, hydrochloric acid was added to the precipitate at a molar ratio of hydrochloric acid to thorium nitrate of 5:1 to dissolve the precipitate. The obtained solution was concentrated, dried and ground to obtain thorium chloride powder.
[0084] The thorium oxide nanofibers obtained in this embodiment are the same as those in Example 1, and the obtained fibers have a uniform diameter and are smooth and dense.
[0085] Example 4: The preparation of thorium oxide nanofibers provided in this example differs from that in Example 1 in that:
[0086] Step (2) Weigh 40g of thorium chloride powder obtained in step (1), dissolve it in 500ml of methanol, add 30g of acetylacetone and 45g of triethylamine, stir thoroughly for 1 hour to obtain a thorium-containing polymer solution.
[0087] In this embodiment, the amount of acetylacetone in the thorium-containing polymer solution is three times that in Example 1. After the solution was left to stand for a long time, a small amount of crystals appeared at the bottom of the container. The precursor obtained in this embodiment has poor spinnability, and the prepared fibers are short in length and have extremely low strength.
[0088] Example 5: The preparation of thorium oxide nanofibers provided in this example differs from that in Example 1 in that:
[0089] The thorium-containing polymer solution obtained in step (3) is concentrated under reduced pressure at 45°C until a white agglomerate or crystalline powder is formed. 350 ml of acetone is added to the powder, stirred and dissolved for 1 hour, and then allowed to stand for 10 hours. The filtrate is obtained by filtration and concentrated again under reduced pressure at 45°C until a white powder is formed, which is the thorium polymer fiber precursor.
[0090] Compared to Example 1, the spinnability of the obtained precursor decreased, and the sol-gel filament length became shorter. The strength of the prepared thorium oxide nanofibers also decreased.
[0091] Example 6: The preparation of thorium oxide nanofibers provided in this example differs from that in Example 1 in that:
[0092] The thorium-containing polymer solution obtained in step (3) is concentrated under reduced pressure at 35°C until a white agglomerate or crystalline powder is formed. 1500 ml of acetone is added to the powder, stirred and dissolved for 1 hour, and then allowed to stand for 10 hours. The filtrate is obtained by filtration and concentrated again under reduced pressure at 35°C until a white powder is formed, which is the thorium polymer fiber precursor.
[0093] The surface smoothness of the obtained precursor fiber decreased, and some crystals could be seen precipitating. Therefore, compared with Example 1, the surface of the obtained thorium oxide nanofiber had slag balls.
[0094] Example 7: The preparation of thorium oxide nanofibers provided in this example differs from that in Example 1 in that:
[0095] The thorium polymer solution obtained in step (3) is concentrated under reduced pressure at 35°C until a white agglomerate or crystalline powder is formed. 350 ml of acetone is added to the powder, stirred and dissolved for 1 h, and then allowed to stand for 30 h. The filtrate is obtained by filtration and concentrated again under reduced pressure at 35°C until a white powder is formed, which is the thorium polymer fiber precursor.
[0096] Compared with Example 1, the obtained thorium oxide nanofibers have a uniform diameter, are smooth and dense, indicating that the standing time has no significant effect on the quality of the thorium oxide nanofibers.
[0097] Example 8: The preparation of thorium oxide nanofibers provided in this example differs from that in Example 1 in that:
[0098] Step (4) Weigh 1.5g of the thorium polymer obtained in step (3), add it to 10g of methanol solvent, and then add 15mg of polyethylene oxide (PEO) to obtain a transparent and clear thorium polymer spinning solution. Compared with Example 1, the uniformity of fiber diameter decreased, and beads appeared on some fibers.
[0099] Example 9: The preparation of thorium oxide nanofibers provided in this example differs from that in Example 1 in that:
[0100] Step (4) Weigh 3g of the thorium polymer obtained in step (3), add it to 10g of methanol solvent, and then add 15mg of polyethylene oxide (PEO) to obtain a transparent and clear thorium polymer spinning solution. Compared with Example 1, the obtained fibers become ribbon-like and have a larger diameter.
[0101] Example 10: The preparation of thorium oxide nanofibers provided in this example differs from that in Example 1 in that: in step (5), the electrospinning voltage is 8KV, the spinning solution propulsion speed is 1.5ml / h, the spinning temperature is 30℃, the spinning humidity is 30%, and the take-up distance is 20cm.
[0102] Compared to Example 1, the sol-spinning state is more stable and the fiber diameter is more uniform.
[0103] Example 11: The preparation of thorium oxide nanofibers provided in this example differs from that in Example 1 in that: in step (5), the electrospinning voltage is 8KV, the spinning solution propulsion speed is 3ml / h, the spinning temperature is 25℃, the spinning humidity is 45%, and the take-up distance is 20cm.
[0104] Compared to Example 1, the uniformity of the obtained fibers decreased, and a small number of fibers showed adhesion.
[0105] Example 12: The preparation of thorium oxide nanofibers provided in this example differs from that in Example 1 in that: in step (6), the thorium polymer nanofibers are heated to 800°C in nitrogen at a heating rate of 2°C / min and kept at that temperature for 1 hour.
[0106] The obtained fibers have a uniform diameter, are smooth and dense, and have smaller grains than those in Example 1.
[0107] Example 13: The preparation of thorium oxide nanofibers provided in this example differs from that in Example 1 in that: in step (6), the thorium polymer nanofibers are heated to 1100°C in air at a heating rate of 2°C / min and kept at that temperature for 3 hours.
[0108] The obtained fibers have a uniform diameter, are smooth and dense, and have larger grains than those in Example 1.
[0109] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for preparing a thorium polymer spinning precursor, characterized in that, include: Thorium chloride powder was dissolved in methanol, and acetylacetone and triethylamine were added and stirred thoroughly to obtain a thorium-containing polymer solution. The thorium-containing polymer solution was concentrated under reduced pressure to obtain a white binder or crystalline powder. A first solvent was added to the white binder or crystalline powder, and the soluble matter was dissolved by stirring. The mixture was then allowed to stand and filtered. The solution was concentrated under reduced pressure again to obtain a white powder, which is the thorium polymer fiber-spinning precursor. The first solvent includes one or more of acetone and tetrahydrofuran; The molar ratio of added thorium chloride, acetylacetone, and triethylamine is 1:(0.8~3):(3~5); The stirring reaction time for thorium chloride, acetylacetone, and triethylamine is 0.5 h to 3 h. The temperature for vacuum concentration is 30℃~60℃; 100g of thorium chloride powder is dissolved in 500mL~2000mL of methanol; Each 100g of white binder or crystalline powder is dissolved in 200mL~1000mL of the first solvent.
2. The method for preparing the thorium polymer spinning precursor according to claim 1, characterized in that, Add the first solvent to the white binder or crystalline powder, stir for 0.5 h to 3 h until the soluble substance dissolves, let stand for 1 h to 48 h and then filter.
3. The method for preparing the thorium polymer spinning precursor according to claim 1, characterized in that, The preparation of the thorium chloride powder includes: Thorium nitrate hexahydrate was dissolved in a second solvent and stirred until the solution was clear. Ammonia was then added and stirring continued to form a white precipitate. The white precipitate was filtered out and repeatedly washed with the second solvent. The filtered white precipitate was evenly dispersed in the second solvent, and hydrochloric acid was added dropwise to the solution to completely dissolve the precipitate. The resulting solution was concentrated, evaporated to dryness, and ground to obtain the thorium chloride powder. The second solvent includes one or two of water, methanol, and ethanol.
4. The method for preparing the thorium polymer spinning precursor according to claim 3, characterized in that, Add ammonia water at a molar ratio of thorium nitrate to ammonia water of 1:(3~6); Add hydrochloric acid at a molar ratio of thorium nitrate to hydrochloric acid of 1:(3~6); The white precipitate was repeatedly rinsed with a second solvent until the conductivity of the filtrate was less than 500 μS / cm.
5. A thorium polymer spinning precursor prepared by the method for preparing a thorium polymer spinning precursor according to any one of claims 1-4.
6. A method for preparing thorium oxide nanofibers comprising the thorium polymer spinning precursor of claim 5, characterized in that, include: Thorium polymer spinning precursor, methanol and polyethylene oxide are mixed to prepare a spinning solution; Under high voltage static electricity, electrospinning is used to spin the spinning solution into thorium polymer fiber precursor nanofibers. The thorium polymer spinning precursor nanofibers were heat-treated in a heat treatment atmosphere to obtain the thorium oxide nanofibers. The mass ratio of the added thorium polymer fiber-spinning precursor, methanol, and polyethylene oxide is (50~300):(200~900):1; In the spinning process, the electrospinning voltage is 3kV~20kV, and the spinning solution speed is 0.3mL / h~2mL / h; In the spinning process, the spinning temperature is 20℃~40℃, and the spinning humidity is 15%~45%; In the spinning process, the take-up distance is 5cm to 30cm.
7. The method for preparing thorium oxide nanofibers according to claim 6, characterized in that, In the heat treatment process, the heat treatment atmosphere is nitrogen, argon or air; In the heat treatment process, the heat treatment process is as follows: the temperature is increased to 600℃~1200℃ at a rate of 0.5℃ / min~10℃ / min, held for 1h~5h, and then cooled in the furnace.
8. Thorium oxide nanofibers prepared by the method of thorium oxide nanofibers according to claim 6 or 7.
9. The application of thorium oxide nanofibers as described in claim 8 in neutron shielding materials or breederable nuclear fuels.