Nitrogen-rich organic silicon network material as well as preparation method and application thereof

Abstract

The invention discloses a nitrogen-rich organic silicon network material as well as a preparation method and application thereof, and the preparation method comprises the following steps: in an alkaline environment with a solvent, carrying out nitrogen-hydrogen bond and epoxy group ring-opening addition reaction on a compound containing primary amine or secondary amine and an epoxy group-containing silane coupling agent, and carrying out hydrolytic condensation reaction on alkoxy to obtain the nitrogen-rich organic silicon network material. And freeze-drying to obtain the nitrogen-rich organic silicon network material. The preparation method comprises the following steps: by taking cheap organic amine and an epoxy group-containing silane coupling agent as polymerization units, preparing an organic silicon material through hydrolysis reaction of the silane coupling agent, and introducing the organic amine into the organic silicon material in a covalent bond manner through ring-opening addition of nitrogen-hydrogen bonds of the organic amine and epoxy groups of the epoxy group-containing silane coupling agent. The primary amine, the secondary amine and the tertiary amine can be used as strong binding sites of iodine, so that the adsorption capacity and the removal depth of the material on the iodine are improved; meanwhile, the silicon substrate can ensure that the material has high irradiation resistance and acid resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of adsorption materials, and in particular to a nitrogen-rich organosilicon network material and a preparation method and application thereof. Background Art

[0002] With the development of nuclear energy and nuclear technology, the proportion of radioactive nuclides in the fields of energy, national defense, medicine and industry has been increasing, but this has also led to the generation of a large amount of radioactive waste. Radioactive iodine is the main gaseous pollutant and one of the early warning nuclides for radioactive leakage in nuclear power plants. 129 I has a long half-life of about 1.57×10 7 It is considered to be one of the main sources of long-term radioactive pollutants. 131 Iodine is one of the most widely used radioactive isotopes in nuclear medicine. Its production and use carry the risk of release into the environment. Due to its volatility, diffusivity, and radioactivity, a leak could cause large-scale environmental problems. It can also enter the human body through inhalation or accidental ingestion, causing thyroid cancer or leukemia through internal radiation exposure. Therefore, the monitoring and management of radioactive iodine isotopes are crucial for the sustainable development of the nuclear industry and nuclear medicine, as well as for environmental protection.

[0003] Currently, monitoring of radioactive iodine isotopes primarily utilizes iodine cartridges or other iodine-absorbing devices to continuously sample the air in a specific environment. Adsorbent materials capture radioactive iodine in the air, and detectors measure the characteristic gamma rays emitted by the adsorbed iodine in the cartridges to estimate the radioactive iodine content in the environment, thereby monitoring the operation of nuclear power plants or other nuclear-related departments. Therefore, both the monitoring and control of radioactive iodine depend on the iodine capture performance of the adsorbent material. For the monitoring and control of radioactive iodine, the depth of iodine isotope removal in the mobile gas phase is even more important than the adsorption capacity, as it affects the accuracy of monitoring data and whether the emitted gases meet standards. However, different environments present different interfering factors. For example, the nuclear reprocessing environment is highly radioactive and contains volatile organic compounds and acidic vapors; while the monitoring environment has low iodine concentrations and the air also contains water vapor and suspended microparticles, these are major challenges to the effective capture of iodine.

[0004] Currently, functional materials used for capturing and enriching radioactive iodine primarily include porous carbon materials impregnated with organic amines, metal-doped materials, metal-organic frameworks (MOFs), and covalent organic frameworks (COFs). Amine-impregnated activated carbon is the most commonly used iodine adsorption material in nuclear reprocessing and iodine cartridges. It offers low cost and high iodine removal depth. However, the organic amines in this material are volatile, and prolonged storage can reduce its adsorption efficiency or even render it ineffective. Furthermore, the iodine-adsorbed material can also be contaminated by iodine secondary contamination due to the volatilization of the organic amines. Metal-doped materials, such as silver and bismuth, offer the advantage of high removal depth, but they are expensive, have low adsorption capacity, and are significantly affected by water vapor, limiting their widespread application. Organic porous framework materials, including MOFs, COFs, and CMPs, are recently developed, highly efficient iodine adsorbents. They possess high specific surface area, tunable pore structure, excellent radiation resistance, and high adsorption capacity. However, their preparation is complex, the reaction conditions are demanding, and the cost is high.

[0005] Therefore, in view of the technical and performance bottlenecks of existing iodine adsorption materials in terms of adsorption efficiency, selectivity, stability and preparation cost, it is of great significance to research and develop a type of low-cost silicone network material with high removal depth and adsorption capacity for volatile iodine, as well as high selectivity and stability, so as to achieve efficient adsorption and enrichment of radioactive iodine in nuclear reprocessing and low iodine concentration environments. Summary of the Invention

[0006] The present invention addresses the deficiencies in the prior art and provides a nitrogen-rich organosilicon network material, its preparation method, and its application. The material utilizes inexpensive organic amines and epoxy-containing silane coupling agents as polymerization units. The organic amine is prepared through a hydrolysis reaction of the silane coupling agent. The organic amine is covalently introduced into the organosilicon material through ring-opening addition of the nitrogen-hydrogen bond of the organic amine to the epoxy group of the epoxy-containing silane coupling agent. This prevents the degradation of adsorption performance and secondary contamination caused by volatilization of the organic amine. Furthermore, the primary, secondary, and tertiary amines serve as strong binding sites for iodine, thereby increasing the material's iodine adsorption capacity and removal depth. Furthermore, the silicon substrate ensures the material's high radiation and acid resistance, enabling efficient adsorption and enrichment of volatile iodine isotopes.

[0007] In order to solve the above technical problems, the first aspect of the present invention provides a method for preparing a nitrogen-rich organosilicon network material, comprising the following steps:

[0008] In an alkaline environment with a solvent, the compound containing primary or secondary amine and the epoxy-containing silane coupling agent undergo a ring-opening addition reaction of nitrogen-hydrogen bonds with epoxy groups, as well as a hydrolysis condensation reaction of alkoxy groups, and the nitrogen-rich organosilicon network material is obtained after freeze-drying.

[0009] The present invention uses low-cost organic amine and epoxy-containing silane coupling agent as reaction substrates. In an alkaline environment, the silane coupling agent undergoes a hydrolysis reaction to prepare an organic silicon material. Simultaneously, the nitrogen-hydrogen bond of the organic amine reacts with the epoxy group of the epoxy-containing silane coupling agent through a ring-opening addition reaction, thereby introducing a large amount of organic amine into the organic silicon material in the form of a covalent bond. This avoids reduced adsorption performance and secondary pollution caused by volatilization of the organic amine. At the same time, a large amount of organic amine in the organic silicon can serve as strong binding sites for iodine due to the primary, secondary and tertiary amines, thereby achieving a high adsorption capacity and removal depth of the material for iodine. In addition, the organic silicon base can ensure that the material has high radiation resistance and acid resistance, thereby achieving efficient adsorption and enrichment of volatile iodine isotopes.

[0010] Furthermore, the compound containing primary or secondary amine is:

[0011]

[0012]

[0013] One or more of , where n is an integer.

[0014] Furthermore, the epoxy-containing silane coupling agent is: One or more of the .

[0015] Furthermore, the temperature of the ring-opening addition reaction and the hydrolysis condensation reaction is 25-100° C., and the time is 2-48 hours.

[0016] Furthermore, the solvent is one or more of water, methanol, ethanol, toluene, and tetrahydrofuran.

[0017] Furthermore, the mass ratio of the compound containing primary or secondary amine to the epoxy-containing silane coupling agent is 1:3-3:1.

[0018] Furthermore, the alkaline condition is achieved by adding an excess of a compound containing a primary or secondary amine and / or an alkali solution. When the feed ratio of the compound containing a primary or secondary amine is high, it can form an alkaline environment that meets the requirements. When the feed ratio is relatively low, the alkaline environment condition is met by additionally adding an alkali solution. The concentration of the alkali solution is 0.01-0.5M.

[0019] Furthermore, the alkali solution is a solution of one or more of potassium carbonate, sodium hydroxide, potassium hydroxide, ammonia water, and triethylamine, preferably an aqueous solution.

[0020] The second aspect of the present invention provides a nitrogen-rich organosilicon network material prepared by the preparation method described in the first aspect.

[0021] The third aspect of the present invention provides use of the nitrogen-rich organosilicon network material described in the second aspect in adsorbing radioactive nuclides, preferably, the radioactive nuclides are radioactive iodine.

[0022] Beneficial effects of the present invention:

[0023] The present invention prepares an organosilicon material through a hydrolysis reaction of a silane coupling agent, and simultaneously introduces a large amount of organic amines into the organosilicon material in the form of covalent bonds through a ring-opening addition reaction between an organic amine containing active hydrogen and an epoxy group of an epoxy-containing silane coupling agent, thereby avoiding a decrease in adsorption performance and secondary pollution caused by volatilization of the organic amines. At the same time, a large amount of organic amines in the organosilicon can serve as strong binding sites for iodine due to the primary, secondary and tertiary amines, thereby achieving a high adsorption capacity and removal depth of the material for iodine.

[0024] The organic silicon base in the nitrogen-rich organic silicon network material prepared by the present invention can ensure that the material has high radiation resistance and acid resistance, so as to achieve efficient adsorption and enrichment of volatile iodine isotopes.

[0025] The invention uses organic amine and silane coupling agent as polymerization units, has low cost and simple preparation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 FTIR spectra of the material of Example 1 of the present invention, wherein: a, KH560; b, PEI; c, NSF-PEI-1; d, NSF-PEI-2; e, NSF-PEI-3;

[0028] Figure 2 The solid state of the material of Example 1 of the present invention 29 Si NMR spectra, where: c, NSF-PEI-1; d, NSF-PEI-2; e, NSF-PEI-3;

[0029] Figure 3 This is the XPS spectrum of the material of Example 1 of the present invention, wherein: c, NSF-PEI-1; d, NSF-PEI-2; e, NSF-PEI-3;

[0030] Figure 4In the figure, AC are the EDS spectra of NSF-PEI-1, NSF-PEI-2 and NSF-PEI-3 in Example 1, and DF are the SEM images of the products NSF-PEI-1, NSF-PEI-2 and NSF-PEI-3 in Example 1;

[0031] Figure 5 In the figure, A is a comparison chart of iodine adsorption of NSF-PEI-1, NSF-PEI-2, and NSF-PEI-3 under the same conditions in Example 1, and B is a comparison chart of iodine adsorption of NSF-PEI-2 at different temperatures;

[0032] Figure 6 In the figure, A is the room temperature static iodine adsorption capacity versus time curve of NSF-PEI-2 in Example 1, and B is the dynamic iodine removal efficiency versus time curve of NSF-PEI-2;

[0033] Figure 7 This is a comparison chart of the adsorption efficiency of iodine vapor by NSF-PEI-2 in Example 1 in the presence of water, n-hexane or 5% HNO3;

[0034] Figure 8 A is the FTIR graph of the product of Example 1 after irradiation, wherein: a, NSF-PEI-1; b, NSF-PEI-2; c, NSF-PEI-3; B is a comparison of the adsorption capacity of the product of Example 1 before and after irradiation;

[0035] Figure 9 This is the FTIR spectrum of the product of Example 2, where: a, NSF-TEPA-1; b, NSF-TEPA-2;

[0036] Figure 10 In the figure, AB are EDS spectra of NSF-TEPA-1 and NSF-TEPA-2, products of Example 2, respectively; CD are SEM images of NSF-TEPA-1 and NSF-TEPA-2, products of Example 2, respectively;

[0037] Figure 11 This is a comparison chart of iodine adsorption in the gas phase of the products NSF-TEPA-1 and NSF-TEPA-2 of Example 2 at 75°C. DETAILED DESCRIPTION

[0038] The following will provide a clear and complete description of the technical solutions of the present invention in conjunction with specific embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0039] Example 1

[0040] This embodiment relates to a method for preparing a nitrogen-rich organosilicon network material, comprising the following steps:

[0041] In groups, 0.5 g of polyethyleneimine (PEI) was dissolved in 10 mL of H2O and stirred for 10 minutes. The solution became alkaline. Then, different amounts of γ-(2,3-epoxypropoxy)propyltrimethoxysilane (KH560) were added dropwise and stirred at 75°C for 2 hours. This caused hydrolysis and condensation of the silyl groups in KH560, as well as a ring-opening addition reaction between the primary or secondary amines of PEI and the epoxy groups in KH560. The solution gradually gelled. The resulting gel was washed with deionized water and freeze-dried to obtain a white material (NSF-PEI). The products were labeled NSF-PEI-1, NSF-PEI-2, and NSF-PEI-3 at a mass ratio of PEI:KH560 of 1:1, 2:1, and 3:1, respectively. The reaction formula for this example is:

[0042]

[0043] Test Example 1-1

[0044] The reactants PEI and KH560 and the products NSF-PEI-1, NSF-PEI-2 and NSF-PEI-3 in Example 1 were subjected to infrared FTIR testing. The results are as follows: Figure 1 As shown in the figure, it can be observed that due to the cross-linking of KH560 and PEI, a peak at 907 cm -1 The epoxy group peak disappears, while the peak at 1193 cm -1 The Si-CH2-R stretching vibration belonging to KH560 appears at 3276 cm -1 The absorption peak centered at 1296 cm is attributed to the stretching vibration of NH and overlaps with the stretching vibration of OH of unpolymerized silanol. -1 、1109cm -1 and 1050cm -1 The absorption peak at 1599 cm is attributed to CN stretching vibration. -1 The absorption peak at 941 cm is attributed to the NH bending vibration, while the absorption peak at 941 cm -1 The absorption peak at 1109 cm-1 is attributed to the bending vibration of Si-OH. -1 The absorption peak at is enhanced compared with PEI, which is due to the presence of a strong Si-O-Si stretching absorption band, which overlaps with the CN stretching vibration.

[0045] The products NSF-PEI-1, NSF-PEI-2 and NSF-PEI-3 of Example 1 were solid-state 29 Si nuclear magnetic resonance (SSNMR) test, the results are as follows Figure 2 As shown, it can be seen that due to the hydrolysis condensation of KH560, NSF-PEI exhibits T2 (-59 ppm) and T3 (-68 ppm) resonances, which are attributed to C-Si(OSi)2(OH) and C-Si(OSi)3, respectively.

[0046] X-ray photoelectron spectroscopy analysis was performed on the products NSF-PEI-1, NSF-PEI-2 and NSF-PEI-3 of Example 1. The results are as follows: Figure 3 As shown, the peaks at 531 eV, 398 eV, 285 eV, 102 eV, and 153 eV are attributed to O 1s, N 1s, C 1s, Si2p, and Si 2s, respectively.

[0047] In summary, the results of FTIR, SSNMR and XPS confirmed the successful synthesis of NSF-PEI.

[0048] Test Example 1-2

[0049] Figure 4 AC are the EDS spectra of the products NSF-PEI-1, NSF-PEI-2 and NSF-PEI-3 in Example 1, respectively. Figure 4 Figures DF are SEM images of NSF-PEI-1, NSF-PEI-2, and NSF-PEI-3, products from Example 1. EDS spectra show that the nitrogen content of the material gradually increases with increasing PEI mass ratio. The SEM images show that NSF-PEI is a blocky particle, and the morphology of NSF-PEI with different feed ratios is the same.

[0050] Test Example 1-3

[0051] Under ambient pressure, NSF-PEI-1, NSF-PEI-2, and NSF-PEI-3 of Example 1 were placed in a sealed container and exposed to iodine vapor at a certain temperature. The mass ratio of iodine to NSF-PEI was 50. The adsorption capacity was measured by gravimetric method at fixed time intervals. The results are as follows: Figure 5 As shown in Figure A. Within the first 3 hours, the adsorption rate of iodine vapor increased rapidly, and after 5 hours, the adsorption equilibrium was reached. The iodine adsorption capacities of NSF-PEI-1, NSF-PEI-2, and NSF-PEI-3 were determined to be 4.6 g / g, 5.8 g / g, and 6.0 g / g, respectively. In addition, the iodine adsorption of NSF-PEI-2 at different temperatures was tested, and the results are shown in Figure A. Figure 5As shown in B. In the range of 55-95 ° C, the adsorption capacity of NSF-PEI-2 increases with the increase of temperature. The maximum iodine vapor adsorption capacity is 5.6 g / g at 55 ° C, and increases to 6.1 g / g at 95 ° C.

[0052] In the static adsorption experiment at room temperature, NSF-PEI-2 was exposed to iodine vapor at 25°C, and its mass change was measured at intervals. Its adsorption capacity was measured by gravimetric method. The results are as follows: Figure 6 As shown in Figure A. In the dynamic adsorption experiment, the iodine vapor required for the experiment was prepared by the gas distribution method. 100 mg of NSF-PEI-2 sample was loaded into a quartz column (column inner diameter 0.8 cm, adsorbent loading height 0.4 cm). Both ends of the adsorption column were filled with absorbent cotton to prevent adsorbent movement. The gas flow rate was 150 mL / min. 0.1 mol / L sodium hydroxide solution was used to wash the iodine-containing nitrogen gas flow before and after column loading. The initial iodine content in the solution and the iodine content remaining after adsorption were determined by ultraviolet spectrometry. The results are shown in Figure 1. Figure 6 As shown in B.

[0053] Depend on Figure 6 As shown in Figure A, in the static adsorption experiment at room temperature, the iodine adsorption capacity of NSF-PEI-2 slowly increases with the increase of adsorption time until it reaches adsorption equilibrium at 155h, and its maximum adsorption capacity can reach 6g / g. Figure 6 As shown in Figure B, in the dynamic adsorption experiment, NSF-PEI-2 can achieve 100% iodine vapor removal rate within 4.6 h, that is, 100 mg of NSF-PEI-2 can completely purify 41.2 L of iodine vapor with a concentration of 284 mg / m at a flow rate of up to 150 mL / min at 25 °C. 3 iodine-containing nitrogen. As the amount of filtered gas increased, the iodine removal rate of the material decreased, but it still maintained an iodine removal rate of 95% within 27.5 hours (i.e., 247.5L of iodine-containing nitrogen). Subsequently, the iodine removal efficiency of NSF-PEI-2 slowly decreased, finally falling to 0% after 274 hours. By weighing the mass change before and after adsorption, the adsorption capacity of NSF-PEI-2 in dynamic adsorption was 3.7g / g, and its dynamic adsorption capacity can reach 61.2% of its static adsorption capacity.

[0054] Test Example 1-4

[0055] At 75°C, NSF-PEI-2 was exposed to iodine vapor in the presence of a certain amount of water, n-hexane, or 5% nitric acid for 24 hours to examine its selectivity. Figure 7 As shown, where q e,i is the adsorption capacity of NSF-PEI-2 in the presence of water, n-hexane, or nitric acid, qe,b is the adsorption capacity of NSF-PEI-2 in air (Blank). It can be seen that in the presence of gaseous organic solvents, water vapor or acidic atmosphere, the iodine adsorption capacity of NSF-PEI-2 remains above 95% of the blank group.

[0056] Test Example 1-5

[0057] 150 mg of NSF-PEI-1, NSF-PEI-2 and NSF-PEI-3 with different nitrogen contents were sealed in colorless glass bottles. 60 Co was used as the emission source and irradiated with 200 kGy of gamma rays at a dose rate of 2.6 kGy / h. The chemical structure of the irradiated sample was characterized by FTIR and its adsorption capacity for iodine vapor was measured. The results are shown in Figure 2. Figure 8 As shown in A and B. Comparison of FTIR spectra of NSF-PEI before and after irradiation ( Figure 1 and Figure 8 A), it can be found that the material before and after irradiation basically maintains the same characteristic peaks, and the adsorption capacity of iodine vapor of NSF-PEI after irradiation at 75°C remains above 95% of that of the original sample ( Figure 8 In B, q e is the adsorption capacity of NSF-PEI after γ-ray irradiation, q0 is the adsorption capacity of NSF-PEI before γ-ray irradiation), indicating that NSF-PEI has good radiation resistance.

[0058] Example 2

[0059] In groups, 0.5 mol of tetraethylenepentamine (TEPA) was dissolved in 50 mL of H₂O and stirred for 10 minutes, resulting in an alkaline solution. Subsequently, varying amounts of γ-(2,3-epoxypropyloxy)propyltrimethoxysilane (KH560) were added dropwise and stirred at 75°C for 2 hours. This resulted in hydrolysis and condensation of the silyl groups in KH560, as well as ring-opening addition of the primary or secondary amines of TEPA with the epoxy groups in KH560. The solution gradually gelled. The resulting gel was washed with deionized water and freeze-dried to obtain a white material (NSF-TEPA). The products at the mass ratios of TEPA:KH560 = 1:2 and 1:1, respectively, were labeled NSF-TEPA-1 and NSF-TEPA-2.

[0060] Test Example 2-1

[0061] The products NSF-TEPA-1 and NSF-TEPA-2 of Example 2 were subjected to FTIR analysis. The results are as follows: Figure 9 As shown, it can be seen that 3287cm -1The absorption peak centered at 2929 cm is attributed to the stretching vibration of NH and overlaps with the stretching vibration of OH of the unhydrolyzed polymerized silanol. -1 and 2852cm -1 The absorption peak at 1451 cm is attributed to the symmetric and antisymmetric stretching vibrations of methylene (-CH2-). -1 The absorption peak at 1305cm is attributed to the bending vibration of methylene (-CH2-). -1 、1093cm -1 and 1018cm -1 The absorption peak at 1093 cm is attributed to the CN stretching vibration. The Si-O-Si stretching vibration absorption peak is at 1093 cm -1 The peaks overlap. At 1198cm -1 The absorption peak is attributed to the Si-CH2-R stretching vibration and is located at 933 cm -1 The absorption peak at is attributed to the bending vibration of Si-OH. Thus, the FTIR results confirm the successful synthesis of NSF-TEPA.

[0062] Test Example 2-2

[0063] Figure 10 AB are the EDS spectra of NSF-TEPA-1 and NSF-TEPA-2, products of Example 2, respectively. Figure 10 Figures C and D are SEM images of NSF-TEPA-1 and NSF-TEPA-2, products from Example 2. EDS spectra show that the nitrogen content of the materials gradually increases with increasing TEPA mass ratio. The SEM images show that NSF-TEPA-1 is a blocky particle, while NSF-TEPA-2 is an irregular porous polymer.

[0064] Test Example 2-3

[0065] Under ambient pressure, a certain amount of NSF-TEPA was placed in a sealed container and exposed to iodine vapor at 75°C. The mass ratio of iodine to NSF-TEPA was 50:1. The iodine adsorption capacity was measured by gravimetric method at a predetermined time. Figure 11 As shown, the iodine adsorption capacities of NSF-TEPA-1 and NSF-TEPA-2 were determined to be 2.8 g / g and 3.6 g / g, respectively.

[0066] The present invention has been described in detail above with reference to specific embodiments and exemplary examples. However, these descriptions should not be construed as limiting the present invention. Those skilled in the art will appreciate that various equivalent substitutions, modifications, or improvements may be made to the technical solutions and implementations of the present invention without departing from the spirit and scope of the present invention, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for preparing a nitrogen-rich organosilicon network material, characterized in that: The steps include: In an alkaline environment with a solvent, the compound containing primary or secondary amine and the epoxy-containing silane coupling agent undergo a ring-opening addition reaction of nitrogen-hydrogen bonds with epoxy groups, as well as a hydrolysis condensation reaction of alkoxy groups, and the nitrogen-rich organosilicon network material is obtained after freeze-drying.

2. The method for preparing the nitrogen-rich organosilicon network material according to claim 1, wherein: The compound containing primary amine or secondary amine is: One or more of , where n is an integer.

3. The method for preparing the nitrogen-rich organosilicon network material according to claim 1, wherein: The epoxy-containing silane coupling agent is: One or more of the .

4. The method for preparing the nitrogen-rich organosilicon network material according to claim 1, wherein: The temperature of the ring-opening addition reaction and the hydrolysis condensation reaction is 25-100° C., and the time is 2-48 hours.

5. The method for preparing the nitrogen-rich organosilicon network material according to claim 1, wherein: The solvent is one or more of water, methanol, ethanol, toluene and tetrahydrofuran.

6. The method for preparing the nitrogen-rich organosilicon network material according to claim 1, wherein: The mass ratio of the compound containing primary or secondary amine to the epoxy-containing silane coupling agent is 1:3-3:

1.

7. The method for preparing the nitrogen-rich organosilicon network material according to claim 1, wherein: The alkaline condition is achieved by adding an excess of a compound containing a primary or secondary amine and / or adding an alkali solution, wherein the concentration of the alkali solution is 0.01-0.5M.

8. The method for preparing the nitrogen-rich organosilicon network material according to claim 7, wherein: The alkali solution is a solution of one or more of potassium carbonate, sodium hydroxide, potassium hydroxide, ammonia water, and triethylamine.

9. A nitrogen-rich organosilicon network material prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the nitrogen-rich organosilicon network material according to claim 9 in adsorbing radioactive nuclides.

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