Scrambling material for improving abundance of stable isotope and preparation method thereof

Abstract

The invention belongs to the technical field of stable isotope catalytic conversion, and discloses a frequency disturbing material for improving abundance of stable isotopes and a preparation method of the frequency disturbing material. The preparation method comprises the following steps: mixing boric acid, melamine, sodium hydroxide, fucoxanthin, polyacrylamide, N, N-methylene bisacrylamide, ammonium persulfate and water, dehydrating, synthesizing under a protective atmosphere, and preserving heat under an aerobic condition to obtain porous boron nitride powder; mixing the porous boron nitride powder, a dispersing agent and water to obtain a boron nitride dispersion liquid; and mixing the boron nitride dispersion liquid with a silver nitrate solution, adding a sodium borohydride solution, and carrying out a reduction reaction to obtain the frequency disturbing material for improving the abundance of the stable isotope. The frequency disturbing material disclosed by the invention can realize low-temperature catalytic conversion, has good recycling performance, brings new breakthrough and possibility to the field of isotope conversion, and is expected to provide powerful support for research and development of related fields.

Description

Technical Field

[0001] The invention relates to the technical field of stable isotope catalytic conversion, and in particular to a scrambling material for increasing the abundance of stable isotopes and a preparation method thereof. Background Art

[0002] In the existing technology, the application fields of stable isotopes are constantly expanding. As we all know, carbon contains two stable isotopes: 12 C and 13 C. Oxygen has three stable isotopes 16 O. 17 O and 18 O, thus forming six molecules with different stable isotopes. 13 The process of product C is to use the different boiling points caused by the different molecular weights of the six molecules to enrich the heavy components at the bottom of the distillation tower and the light components at the top of the tower, thereby obtaining an enriched 13 However, in the later stage of the separation process, the diatomic isotope gas is often interfered by other isotopes, which limits the bottom discharge of the tower. 13 The abundance of C.

[0003] In order to solve this problem, catalytic conversion was introduced in the middle link of cryogenic distillation. The key to this method is to add isotope scrambling materials after the distillation tower. The scrambling materials can promote the reaction between the same molecules of isotope gas, recombine isotope atoms, and form isotope compounds that are easy to separate, thereby further purifying the isotopes, and then passing them into the next level of distillation tower, which can improve 13 Therefore, catalytic conversion and scrambling materials play a vital role in the cryogenic distillation process, and they provide effective technical means for obtaining high-abundance isotopes.

[0004] However, some scrambling materials, such as tungsten wire, have a reaction temperature as high as 1200°C, which means that a large amount of energy is required to heat the scrambling material, greatly increasing energy consumption. In addition, the service life of the above-mentioned scrambling materials at high temperatures is relatively short, which not only affects production efficiency, but also increases the frequency of material replacement, further increasing production costs and operational complexity. Considering the above unfavorable factors, the research and development and application of scrambling materials face great difficulties in industrial production. Therefore, in order to promote the industrial production of isotopes, the preparation of a more economical, efficient and durable scrambling material is an urgent problem to be solved. Summary of the invention

[0005] The object of the present invention is to provide a scrambling material for improving the abundance of stable isotopes and a preparation method thereof, so as to solve the technical problems of short service life, low activity and high energy consumption of existing scrambling materials.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for preparing a scrambling material for increasing the abundance of stable isotopes, comprising the following steps:

[0008] (1) mixing boric acid, melamine, sodium hydroxide, phycocyanin, polyacrylamide, N,N-methylenebisacrylamide, ammonium persulfate and water, and dehydrating to obtain a precursor powder;

[0009] (2) Under a protective atmosphere, subjecting the precursor powder to a synthetic reaction to obtain a crude product; then, subjecting the crude product to a heat preservation treatment under an aerobic condition to obtain a porous boron nitride powder;

[0010] (3) Mixing porous boron nitride powder, a dispersant and water to obtain a boron nitride dispersion; mixing the boron nitride dispersion with a silver nitrate solution, adding a sodium borohydride solution for reduction reaction, and obtaining a scrambling material for increasing the abundance of stable isotopes.

[0011] Preferably, in the method for preparing a scrambling material for increasing the abundance of stable isotopes, the mass ratio of the boric acid, the melamine, the sodium hydroxide, the phycocyanin, the polyacrylamide, the N,N-methylenebisacrylamide and the ammonium persulfate in step (1) is 1:2-8:0.04-0.1:0.1-0.4:0.02-0.06:0.001-0.006:0.005-0.01.

[0012] Preferably, in the method for preparing a scrambling material for increasing the abundance of stable isotopes, the dehydration temperature in step (1) is 40 to 60° C. and the dehydration time is 1 to 2 days.

[0013] Preferably, in the method for preparing a scrambling material for increasing the abundance of stable isotopes, the temperature of the synthesis reaction in step (2) is 700-800° C., the time is 8-15 h, and the pressure is 0.2-0.5 MPa.

[0014] Preferably, in the method for preparing a scrambling material for increasing the abundance of stable isotopes, the temperature of the insulation treatment in step (2) is 400-500° C. and the time is 10-15 hours.

[0015] Preferably, in the method for preparing a scrambling material for increasing the abundance of stable isotopes, the dispersant in step (3) is sodium dodecylbenzene sulfonate.

[0016] Preferably, in the method for preparing a scrambling material for increasing the abundance of stable isotopes, the mass volume ratio of the porous boron nitride powder, the dispersant and the water in step (3) is 0.5-1 g: 0.25-0.4 g: 30 mL.

[0017] Preferably, in the method for preparing a scrambling material for increasing the abundance of stable isotopes, the mass ratio of the porous boron nitride powder in step (3), the silver nitrate in the silver nitrate solution, and the sodium borohydride in the sodium borohydride solution is 1-2:1:0.3-0.5.

[0018] Preferably, in the method for preparing a scrambling material for increasing the abundance of stable isotopes, the temperature of the reduction reaction in step (3) is 15 to 25° C., and the time is 0.5 to 2 hours.

[0019] The present invention also provides a scrambling material for increasing the abundance of stable isotopes prepared by the preparation method of the scrambling material for increasing the abundance of stable isotopes.

[0020] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention first mixes the raw material for preparing boron nitride with a carbon source, carbonizes and then removes carbon to obtain a continuous porous boron nitride powder. Subsequently, the porous boron carbide powder is mixed with silver nitrate, and under the reduction effect of sodium borohydride, the silver nitrate is reduced to nano silver and loaded on the porous boron carbide powder to obtain the scrambling material of the present invention.

[0022] The scrambling material of the present invention has shown significant advantages in the field of isotope conversion. It can achieve catalytic conversion of isotopes at relatively low temperatures (500°C and below). Compared with the high temperature and high pressure conditions required by traditional methods, this undoubtedly greatly reduces energy consumption and makes the isotope conversion process more economical and efficient.

[0023] At the same time, the scrambled material of the present invention not only has a good catalytic effect, but also has good recycling performance. This means that the material can be reused many times, which not only reduces material waste, but also reduces production costs and improves economic benefits. In practical applications, the reusability of the scrambled material is an important manifestation of its practical application value, and the present invention has made a significant breakthrough in this aspect.

[0024] In addition, the scrambled material of the present invention can be used for stable isotopes 13 C. 18O. This synchronous conversion capability enables the material to be used in multiple fields such as isotope research, biomedicine, and environmental science. For example, in the field of biomedicine, isotope-labeled drugs can be used to study the metabolic process of drugs in the body; in the field of environmental science, isotope tracing technology can be used to study the migration and transformation process of pollutants, which has broad application prospects. DETAILED DESCRIPTION

[0025] The present invention provides a method for preparing a scrambling material for increasing the abundance of stable isotopes, comprising the following steps:

[0026] (1) mixing boric acid, melamine, sodium hydroxide, phycocyanin, polyacrylamide, N,N-methylenebisacrylamide, ammonium persulfate and water, and dehydrating to obtain a precursor powder;

[0027] (2) Under a protective atmosphere, subjecting the precursor powder to a synthetic reaction to obtain a crude product; then, subjecting the crude product to a heat preservation treatment under an aerobic condition to obtain a porous boron nitride powder;

[0028] (3) Mixing porous boron nitride powder, a dispersant and water to obtain a boron nitride dispersion; mixing the boron nitride dispersion with a silver nitrate solution, adding a sodium borohydride solution for reduction reaction, and obtaining a scrambling material for increasing the abundance of stable isotopes.

[0029] In the present invention, the method of mixing boric acid, melamine, sodium hydroxide, chlorophyll, polyacrylamide, N,N-methylenebisacrylamide, ammonium persulfate and water in step (1) is preferably as follows: boric acid, melamine, sodium hydroxide and chlorophyll are sequentially added to water for mixing, polyacrylamide and N,N-methylenebisacrylamide are then sequentially added, the mixture is mixed in a water bath, and finally ammonium persulfate is added for further mixing.

[0030] In the present invention, the temperature of the water bath condition is preferably 50 to 60°C, more preferably 55 to 60°C, and even more preferably 60°C.

[0031] The present invention does not limit the source of the fucoidan in step (1), and commercially available products known to those skilled in the art may be used.

[0032] In the present invention, the polyacrylamide in step (1) is preferably non-ionic polyacrylamide; the molecular weight of the polyacrylamide is preferably 8 million to 12 million, more preferably 8 million to 10 million, and more preferably 10 million.

[0033] In the present invention, the mass ratio of the boric acid, the melamine, the sodium hydroxide, the phycocyanin, the polyacrylamide, the N,N-methylenebisacrylamide and the ammonium persulfate in step (1) is preferably 1:2-8:0.04-0.1:0.1-0.4:0.02-0.06:0.001-0.006:0.005-0.01, further preferably 1:4-8:0.06-0.08:0.25-0.4:0.03-0.06:0.002-0.004:0.008-0.01, and more preferably 1:6:0.08:0.4:0.06:0.004:0.01.

[0034] In the present invention, the mass volume ratio of the boric acid to the water in step (1) is preferably 1 g: 30-60 mL, more preferably 1 g: 35-50 mL, and even more preferably 1 g: 45 mL.

[0035] In the present invention, the dehydration temperature in step (1) is preferably 40-60°C, more preferably 45-55°C, and more preferably 50°C; the dehydration time is preferably 1-2 days, more preferably 1.5-2 days, and more preferably 2 days.

[0036] In the present invention, the step (1) preferably further comprises grinding and dispersing after the dehydration. The present invention does not limit the conditions of the grinding and dispersing, and a method well known to those skilled in the art can be used.

[0037] In the present invention, the protective atmosphere in step (2) is preferably nitrogen or argon, more preferably nitrogen.

[0038] In the present invention, the temperature of the synthesis reaction in step (2) is preferably 700-800°C, more preferably 720-780°C, more preferably 780°C; the time is preferably 8-15h, more preferably 10-15h, more preferably 12h; the pressure is preferably 0.2-0.5MPa, more preferably 0.2-0.4MPa, more preferably 0.4MPa.

[0039] In the present invention, the synthesis reaction in step (2) preferably further comprises washing and grinding in sequence. The present invention does not limit the conditions of the washing and grinding, and the schemes well known to those skilled in the art can be adopted.

[0040] In the present invention, the temperature of the heat preservation treatment in step (2) is preferably 400-500°C, more preferably 420-450°C, and more preferably 450°C; the time is preferably 10-15h, more preferably 12-15h, and more preferably 12h.

[0041] In the present invention, the dispersant in step (3) is preferably sodium dodecylbenzene sulfonate.

[0042] In the present invention, the mass volume ratio of the porous boron nitride powder, the dispersant and the water in step (3) is preferably 0.5-1g: 0.25-0.4g: 30mL, more preferably 0.7-1g: 0.35-0.4g: 30mL, and more preferably 1g: 0.4g: 30mL.

[0043] In the present invention, the method for mixing the porous boron nitride powder, dispersant and water in step (3) is preferably ultrasound; the frequency of the ultrasound is preferably 20 to 40 kHz, more preferably 25 to 40 kHz, and more preferably 40 kHz; the time of the ultrasound is preferably 1 to 1.5 h, more preferably 1.2 to 1.5 h, and more preferably 1.5 h.

[0044] In the present invention, the mass ratio of the porous boron nitride powder, the silver nitrate in the silver nitrate solution and the sodium borohydride in the sodium borohydride solution in step (3) is preferably 1-2:1:0.3-0.5, more preferably 1-1.6:1:0.4-0.5, and more preferably 1.4:1:0.4.

[0045] The present invention does not limit the concentrations of the silver nitrate solution and the sodium borohydride solution in step (3), and any solution familiar to those skilled in the art may be used.

[0046] In the present invention, the temperature of the reduction reaction in step (3) is preferably 15-25°C, more preferably 20-25°C, and more preferably 20°C; the time is preferably 0.5-2h, more preferably 1-2h, and more preferably 1.5h.

[0047] In the present invention, the rotation speed of mixing the boron nitride dispersion and the silver nitrate solution in step (3) and the reduction reaction is independently preferably 600 to 1000 r / min, more preferably 750 to 1000 r / min, and more preferably 850 r / min.

[0048] In the present invention, after the reduction reaction in step (3), the process preferably further comprises: washing, centrifugation, and freeze-drying in sequence. The present invention does not limit the conditions of washing, centrifugation, and freeze-drying, and any method known to those skilled in the art can be used.

[0049] The present invention also provides a scrambling material for increasing the abundance of stable isotopes prepared by the preparation method of the scrambling material for increasing the abundance of stable isotopes.

[0050] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] Example 1

[0052] This embodiment provides a method for preparing a scrambling material for increasing the abundance of stable isotopes, comprising the following steps:

[0053] (1) 1 part of boric acid, 6 parts of melamine, 0.08 parts of sodium hydroxide and 0.4 parts of phycocyanin are sequentially added into 50 mL / g of water (the volume of water is calculated relative to the amount of boric acid used) and stirred, and then 0.06 parts of nonionic polyacrylamide (molecular weight of 10 million) and 0.004 parts of N,N-methylenebisacrylamide are sequentially added, mixed and stirred in a water bath at 60° C., and finally 0.01 parts of ammonium persulfate are added and stirred continuously to obtain a precursor gel; the precursor gel is dehydrated at 50° C. for 2 days, and ground and dispersed to obtain a precursor powder;

[0054] (2) placing the precursor powder into a heating furnace, reacting it at 780°C and 0.4 MPa for 12 hours under nitrogen protection, and then washing and grinding it in sequence to obtain a crude product; then the crude product is kept at 450°C in an air environment for decarbonization for 12 hours to obtain a porous boron nitride powder;

[0055] (3) 1 g of porous boron nitride powder, 0.4 g of sodium dodecylbenzene sulfonate and 30 mL of water were mixed and ultrasonically treated at 40 kHz for 1.5 h to obtain a boron nitride dispersion; the boron nitride dispersion was mixed and stirred with a silver nitrate solution at 800 r / min, and a sodium borohydride solution was added. The mass ratio of porous boron nitride powder, silver nitrate and sodium borohydride in the system was 1:1:0.4. The reduction reaction was carried out at 20°C and 1000 r / min for 1 h, and then washed, centrifuged and freeze-dried in sequence to obtain a scrambling material for increasing the abundance of stable isotopes.

[0056] The scrambled material prepared in Example 1 was loaded into an isotope scrambler. The operating temperature of the scrambler was 450°C. 12 C 18 The CO raw material gas of O is passed into the isotope scrambler, and the isotope molecules complete the catalytic reaction on the surface of the scrambler material. The reaction products are analyzed by isotope mass spectrometer. 12 C 18 The abundance of O was 0.92%, the conversion rate was 88.5%, and no byproduct CO2 was formed in the reaction product. After repeating the catalytic conversion of CO raw gas with the same abundance for 6 times,12 C 18 The conversion rate of O is still 80.2%, and the catalytic activity retention rate of the scrambling material is 90.62%, which has good recycling performance.

[0057] Example 2

[0058] This embodiment provides a method for preparing a scrambling material for increasing the abundance of stable isotopes, comprising the following steps:

[0059] (1) 1 part of boric acid, 2 parts of melamine, 0.06 parts of sodium hydroxide and 0.2 parts of phycocyanin are sequentially added to 30 mL / g of water (the volume of water is calculated relative to the amount of boric acid used) and stirred, and then 0.03 parts of non-ionic polyacrylamide (molecular weight 8 million) and 0.002 parts of N,N-methylenebisacrylamide are sequentially added, mixed and stirred in a water bath at 50° C., and finally 0.006 parts of ammonium persulfate are added and stirred continuously to obtain a precursor gel; the precursor gel is dehydrated at 45° C. for 1.5 days, and ground and dispersed to obtain a precursor powder;

[0060] (2) placing the precursor powder into a heating furnace, reacting it at 720°C and 0.3 MPa for 10 hours under nitrogen protection, and then washing and grinding it in sequence to obtain a crude product; then the crude product is kept at 420°C in an air environment for 15 hours for carbon removal to obtain a porous boron nitride powder;

[0061] (3) 0.7 g of porous boron nitride powder, 0.35 g of sodium dodecylbenzene sulfonate and 30 mL of water were mixed and ultrasonically treated at 25 kHz for 1 h to obtain a boron nitride dispersion; the boron nitride dispersion was mixed and stirred with a silver nitrate solution at 650 r / min, and a sodium borohydride solution was added. The mass ratio of porous boron nitride powder, silver nitrate and sodium borohydride in the system was 1.4:1:0.3. The reduction reaction was carried out at 25°C and 850 r / min for 2 h, and then washed, centrifuged and freeze-dried in sequence to obtain a scrambling material for increasing the abundance of stable isotopes.

[0062] The scrambled material prepared in Example 2 was loaded into the isotope scrambler. The operating temperature of the scrambler was 400°C. 12 C 18 The CO raw material gas of O is passed into the isotope scrambler, and the isotope molecules complete the catalytic reaction on the surface of the scrambler material. The reaction products are analyzed by isotope mass spectrometer. 12 C 18 The abundance of O was 0.46%, the conversion rate was 87.56%, and no byproduct CO2 was formed in the reaction product. After repeating the catalytic conversion of CO raw gas with the same abundance for 6 times, 12 C 18The conversion rate of O is still 76.8%, and the catalytic activity retention rate of the scrambling material is 87.7%, which has good recycling performance.

[0063] Example 3

[0064] This embodiment provides a method for preparing a scrambling material for increasing the abundance of stable isotopes, comprising the following steps:

[0065] (1) 1 part of boric acid, 6 parts of melamine, 0.04 parts of sodium hydroxide and 0.3 parts of phycocyanin are sequentially added to 45 mL / g of water (the volume of water is calculated relative to the amount of boric acid used) and stirred, and then 0.05 parts of non-ionic polyacrylamide (molecular weight of 12 million) and 0.006 parts of N,N-methylenebisacrylamide are sequentially added, mixed and stirred in a water bath at 50° C., and finally 0.008 parts of ammonium persulfate are added and stirred continuously to obtain a precursor gel; the precursor gel is dehydrated at 55° C. for 1 day, and ground and dispersed to obtain a precursor powder;

[0066] (2) placing the precursor powder into a heating furnace, reacting it at 750°C and 0.2 MPa for 15 hours under argon protection, and then washing and grinding it in sequence to obtain a crude product; then the crude product is kept at 500°C for 10 hours in an air environment to remove carbon, and porous boron nitride powder is obtained;

[0067] (3) 0.8 g of porous boron nitride powder, 0.35 g of sodium dodecylbenzene sulfonate and 30 mL of water were mixed and ultrasonically treated at 35 kHz for 1.2 h to obtain a boron nitride dispersion; the boron nitride dispersion was mixed and stirred with a silver nitrate solution at 600 r / min, and a sodium borohydride solution was added. The mass ratio of porous boron nitride powder, silver nitrate and sodium borohydride in the system was 2:1:0.3. The reduction reaction was carried out at 15°C and 650 r / min for 0.8 h, and then washed, centrifuged and freeze-dried in sequence to obtain a scrambling material for increasing the abundance of stable isotopes.

[0068] The scrambled material prepared in Example 3 was loaded into the isotope scrambler. The operating temperature of the scrambler was 480°C. 12 C 18 The CO raw material gas of O is passed into the isotope scrambler, and the isotope molecules complete the catalytic reaction on the surface of the scrambler material. The reaction products are analyzed by isotope mass spectrometer. 12 C 18 The abundance of O was 0.38%, the conversion rate was 83.47%, and no byproduct CO2 was formed in the reaction product. After repeating the catalytic conversion of CO raw gas with the same abundance for 6 times, 12 C 18 The conversion rate of O is still 70.52%, and the catalytic activity retention rate of the scrambling material is 84.48%, which has good recycling performance.

[0069] Example 4

[0070] This embodiment provides a method for preparing a scrambling material for increasing the abundance of stable isotopes, comprising the following steps:

[0071] (1) 1 part of boric acid, 4 parts of melamine, 0.08 parts of sodium hydroxide and 0.25 parts of phycocyanin are sequentially added to 35 mL / g of water (the volume of water is calculated relative to the amount of boric acid used) and stirred, and then 0.04 parts of nonionic polyacrylamide (molecular weight of 10 million) and 0.003 parts of N,N-methylenebisacrylamide are sequentially added, mixed and stirred in a water bath at 55° C., and finally 0.005 parts of ammonium persulfate are added and stirred continuously to obtain a precursor gel; the precursor gel is dehydrated at 48° C. for 1.2 days, and ground and dispersed to obtain a precursor powder;

[0072] (2) placing the precursor powder into a heating furnace, reacting it at 700°C and 0.35MPa for 8 hours under nitrogen protection, and then washing and grinding it in sequence to obtain a crude product; then the crude product is kept at 440°C in an air environment for decarbonization for 13 hours to obtain a porous boron nitride powder;

[0073] (3) 1 g of porous boron nitride powder, 0.4 g of sodium dodecylbenzene sulfonate and 30 mL of water were mixed and ultrasonically treated at 36 kHz for 1.4 h to obtain a boron nitride dispersion; the boron nitride dispersion was mixed and stirred with a silver nitrate solution at 900 r / min, and a sodium borohydride solution was added. The mass ratio of porous boron nitride powder, silver nitrate and sodium borohydride in the system was 1.6:1:0.5. The reduction reaction was carried out at 20°C and 750 r / min for 1.5 h, and then washed, centrifuged and freeze-dried in sequence to obtain a scrambling material for increasing the abundance of stable isotopes.

[0074] The scrambled material prepared in Example 4 was loaded into the isotope scrambler. The operating temperature of the scrambler was 430°C. 12 C 18 The CO raw material gas of O is passed into the isotope scrambler, and the isotope molecules complete the catalytic reaction on the surface of the scrambler material. The reaction products are analyzed by isotope mass spectrometer. 12 C 18 The abundance of O was 1.5%, the conversion rate was 86.84%, and no byproduct CO2 was formed in the reaction product. After repeating the catalytic conversion of CO raw gas with the same abundance for 6 times, 12 C 18 The conversion rate of O is still 75.81%, and the catalytic activity retention rate of the scrambling material is 87.29%, which has good recycling performance.

[0075] Comparative Example 1

[0076] This comparative example provides a method for preparing a scrambling material, which differs from Example 1 in that step (3) is deleted, and other parameter conditions are the same as those of Example 1.

[0077] The scrambled material prepared in Comparative Example 1 was loaded into an isotope scrambler, the operating temperature of the scrambler was 450°C, and the abundance was 8.03%. 12 C 18 The CO raw material gas of O is passed into the isotope scrambler, and the isotope molecules complete the catalytic reaction on the surface of the scrambler material. The reaction products are analyzed by isotope mass spectrometer. 12 C 18 The abundance of O was 4.69%, the conversion rate was 41.59%, and a small amount of byproduct CO2 was generated in the reaction product. After repeating the catalytic conversion of CO raw gas with the same abundance twice, 12 C 18 The conversion rate of O was only 32.5%, and the catalytic activity retention rate of the scrambled material was only 78.14%.

[0078] In summary, the scrambled material of the present invention can achieve low-temperature catalytic conversion and has good recycling performance, which brings new breakthroughs and possibilities to the field of isotope conversion. Its potential and value in practical applications cannot be ignored, and it is expected to provide strong support for research and development in related fields.

[0079] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a scrambling material for increasing the abundance of stable isotopes, It is characterized in that The following steps are involved: (1) mixing boric acid, melamine, sodium hydroxide, phycocyanin, polyacrylamide, N,N-methylenebisacrylamide, ammonium persulfate and water, and dehydrating to obtain a precursor powder; (2) Under a protective atmosphere, subjecting the precursor powder to a synthetic reaction to obtain a crude product; then, subjecting the crude product to a heat preservation treatment under an aerobic condition to obtain a porous boron nitride powder; (3) Mixing porous boron nitride powder, a dispersant and water to obtain a boron nitride dispersion; mixing the boron nitride dispersion with a silver nitrate solution, adding a sodium borohydride solution for reduction reaction, and obtaining a scrambling material for increasing the abundance of stable isotopes.

2. A method for preparing a scrambling material for increasing the abundance of stable isotopes as claimed in claim 1, It is characterized in that The mass ratio of the boric acid, the melamine, the sodium hydroxide, the phycocyanin, the polyacrylamide, the N,N-methylenebisacrylamide and the ammonium persulfate in step (1) is 1:2-8:0.04-0.1:0.1-0.4:0.02-0.06:0.001-0.006:0.005-0.

01.

3. A method for preparing a scrambling material for increasing the abundance of stable isotopes as claimed in claim 1 or 2, It is characterized in that The dehydration temperature in step (1) is 40-60° C. and the time is 1-2 days.

4. A method for preparing a scrambling material for increasing the abundance of stable isotopes as claimed in claim 1, It is characterized in that The temperature of the synthesis reaction in step (2) is 700-800° C., the time is 8-15 hours, and the pressure is 0.2-0.5 MPa.

5. A method for preparing a scrambling material for increasing the abundance of stable isotopes as claimed in claim 1 or 4, It is characterized in that The temperature of the heat preservation treatment in step (2) is 400-500° C. and the time is 10-15 hours.

6. A method for preparing a scrambling material for increasing the abundance of stable isotopes as claimed in claim 1, It is characterized in that The dispersant in step (3) is sodium dodecylbenzene sulfonate.

7. A method for preparing a scrambling material for increasing the abundance of stable isotopes as claimed in claim 6, It is characterized in that In step (3), the mass volume ratio of the porous boron nitride powder, the dispersant and the water is 0.5-1 g: 0.25-0.4 g: 30 mL.

8. A method for preparing a scrambling material for increasing the abundance of stable isotopes as claimed in claim 7, It is characterized in that In step (3), the mass ratio of the porous boron nitride powder, the silver nitrate in the silver nitrate solution and the sodium borohydride in the sodium borohydride solution is 1-2:1:0.3-0.

5.

9. A method for preparing a scrambling material for increasing the abundance of stable isotopes as claimed in any one of claims 6 to 8, It is characterized in that The temperature of the reduction reaction in step (3) is 15-25° C. and the time is 0.5-2 h.

10. The scrambling material for increasing the abundance of stable isotopes prepared by the method for preparing a scrambling material for increasing the abundance of stable isotopes as claimed in any one of claims 1 to 9.