Radiation-resistant deacidification membrane as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of membrane separation, and particularly provides an anti-radiation deacidification membrane as well as a preparation method and application thereof. The anti-radiation deacidification film comprises a base film and a deacidification film layer, the deacidification film layer is arranged on one side of the base film, the deacidification film layer is formed by a cross-linking reaction of graphene oxide and carbon nanodots under the action of a carboxyl activator, and the mass ratio of the graphene oxide to the carbon nanodots is (10-50): 1. The anti-radiation deacidification membrane is good in structural stability, can be used for deacidification treatment of a metal ion solution, can resist radiation of rays, and is particularly suitable for deacidification of a radioactive isotope metal solution.

Description

Technical Field

[0001] The invention relates to the technical field of membrane separation, and in particular to a radiation-resistant acid removal membrane and a preparation method and application thereof. Background Art

[0002] At present, various α and β radionuclides are used as medical isotopes for radiotherapy of tumors. The therapeutic effect of radionuclides mainly comes from the destruction of tumors by their ionizing radiation. α radionuclides have outstanding advantages in tumor treatment due to their short range (50-90µm) and high linear energy transfer (~100keV) in biological tissues.

[0003] 225 Ac is a very important α-therapy nuclide. 225 The most promising way to apply Ac is to use medium-energy protons (>100 MeV) to bombard thorium palladium to cause thorium fission and separate it from the fission products of thorium. 225 In addition to Ac, there are many other fission nuclides (almost all elements in the periodic table), which require multiple steps of separation to obtain high purity. 225 Ac solution. Therefore, the separation and purification process requires the use of a variety of acids, especially sulfuric acid and nitric acid, which results in the obtained 225 Ac solution is mostly acidic, which is obviously not conducive to 225 Ac is a drug label. Although it can be 225 The acidity of the Ac solution is adjusted to neutral, but 225 Impurity ions are introduced into the Ac solution, and these impurity ions may react with 225 Ac competes with the active sites of the drug to be labeled, resulting in reduced labeling efficiency. Therefore, physical rather than chemical methods are used. 225 The deacidification of Ac solution will be more conducive to 225 Ac drug labeling. 225 Ac is a radioactive nuclide, which requires that the deacidification material used must have a certain radiation resistance to ensure the stability of the deacidification effect. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the prior art at least to a certain extent. To this end, one object of the present invention is to provide an anti-radiation acid removal film and a preparation method and application thereof.

[0005] In a first aspect of the present invention, the present invention provides a radiation-resistant acid-depleting film, the radiation-resistant acid-depleting film comprising: Basement membrane; The acid-deoxidizing film layer is arranged on one side of the base film, and is formed by a cross-linking reaction between graphene oxide and carbon nanodots under the action of a carboxyl activator, and the mass ratio of the graphene oxide to the carbon nanodots is (10-50):1.

[0006] The above-mentioned radiation-resistant deacidification film provided by the present invention comprises a basement membrane and a deacidification film layer, the deacidification film layer is arranged on one side of the basement membrane, and the deacidification film layer is formed by cross-linking of graphene oxide and carbon nanodots under the action of a carboxyl activator. The deacidification film layer formed by cross-linking graphene oxide and carbon nanodots has good structural stability, can be used for deacidification of metal ion solutions, thereby reducing the acidity of the solution, and the deacidification film layer can withstand the irradiation of rays while keeping the membrane structure intact, even if high-dose irradiation has little effect on the deacidification performance of the deacidification film layer, so it is particularly suitable for use as a membrane material for the deacidification of radioactive metal ion solutions. Thus, the radiation-resistant deacidification film has good structural stability, can be used for the deacidification of metal ion solutions, and can withstand the irradiation of rays, and is particularly suitable for the deacidification of radioactive isotope metal solutions.

[0007] Furthermore, the mass ratio of graphene oxide to carbon nanodots in the deacidification film layer is (10-50):1. The inventors found that if the mass ratio of graphene oxide to carbon nanodots is too large, that is, too much graphene oxide is added, the deacidification speed is too slow; if the mass ratio of graphene oxide to carbon nanodots is too small, that is, too little graphene oxide is added, the effective pore size of the membrane is too large, which is not conducive to metal ion retention. Therefore, controlling the mass ratio of graphene oxide to carbon nanodots in the deacidification film layer within the above range can effectively improve the stability of the membrane structure and enhance the deacidification ability of the membrane.

[0008] Preferably, the radiation-resistant deacidification membrane can intercept trivalent cations. Further, the trivalent cations include Fe 3+ Cr 3+ 、Al 3+ 、Au 3+ 、Co 3+ etc., more preferably intercepting high-valent radioactive isotope trivalent cations, wherein the high-valent radioactive isotope trivalent cations include Ac 3+ ,La 3+ or Am 3+ wait.

[0009] Preferably, the radiation-resistant deacidification film has a radiation-resistant dose of 50 kGy-300 kGy.

[0010] According to the above-mentioned radiation-resistant deacidification membrane provided by the present invention, in the deacidification membrane layer, the particle size of the carbon nanodots is 3nm-7nm. For example, the particle size of the carbon nanodots is 3nm, 4nm, 5nm, 6nm, 7nm, etc., or the range between any two of the above values. By controlling the particle size of the carbon nanodots within the above range, the number of ion channels can be effectively regulated, thereby affecting the deacidification efficiency of the membrane.

[0011] According to the above-mentioned radiation-resistant deacidification film provided by the present invention, in the deacidification film layer, the oxygen content of the graphene oxide is 5%-40%. For example, the oxygen content of the graphene oxide is 5%, 10%, 15%, 20%, 30%, 40%, etc., or a range between any two of the above values. By controlling the oxygen content of the graphene oxide within the above range, the dispersibility of the graphene oxide solution can be improved, thereby improving the film-forming effect and enhancing the deacidification performance of the film.

[0012] Preferably, the particle size of the carbon nanodots in the deacidified film layer is 3nm-7nm, and the oxygen content of the graphene oxide is 15%-20%.

[0013] According to the above-mentioned radiation-resistant acid-degrading film provided by the present invention, in the acid-degrading film layer, the mass ratio of the graphene oxide to the carboxyl activator is 1: (1-10), preferably 1: 5. Controlling the mass ratio of the graphene oxide to the carboxyl activator within the above range can ensure that the graphene oxide and the carbon nanodots fully undergo cross-linking reaction, thereby improving the film-forming effect and the uniformity of the film.

[0014] In some embodiments of the present invention, the carboxyl activator is selected from at least one of 1-ethyl-(3-dimethylaminopropyl)carbodiimide (EDC), N-hydroxysuccinimide (NHS), and N,N'-dicyclohexylcarbodiimide (DCC).

[0015] According to the above-mentioned radiation-resistant acid-removing film provided by the present invention, the thickness of the acid-removing film layer is 50nm-150nm. For example, the thickness of the acid-removing film layer is 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 120nm, 130nm, 150nm, etc., or the range between any two of the above-mentioned values. Controlling the thickness of the acid-removing film layer within the above-mentioned range can ensure the efficiency of the film acid-removing.

[0016] According to the above-mentioned radiation-resistant acid-degradation film provided by the present invention, the pore size of the base film is 0.1µm-200µm, preferably 0.4µm-25µm.

[0017] In some embodiments of the present invention, the thickness of the base film is 100µm-200µm.

[0018] In some embodiments of the present invention, the base membrane is selected from one of a polytetrafluoroethylene microporous filter membrane, a mixed cellulose microporous filter membrane, a polypropylene microporous filter membrane, and a polyvinylidene fluoride microporous filter membrane.

[0019] In a second aspect of the present invention, the present invention provides a method for preparing the above-mentioned radiation-resistant acid removal film, the method comprising: (1) mixing a graphene oxide solution, a carbon nanodot solution and a carboxyl activator solution in water and then ultrasonically treating the mixture at room temperature to obtain a membrane slurry; (2) The membrane layer slurry is vacuum filtered and assembled on the base membrane to form a deacidified membrane layer.

[0020] After mixing graphene oxide solution, carbon nanodot solution and carboxyl activator solution in water, ultrasonic treatment is performed at room temperature. Under the action of carboxyl activator, graphene oxide and carbon nanodot undergo cross-linking reaction. The film layer slurry obtained after the reaction is vacuum filtered and assembled on the base film, that is, a deacidification film layer is formed on the base film. At the same time, the preparation method of the radiation-resistant deacidification film is simple, easy to operate, and the prepared materials are easy to obtain, low in cost, and have significant economic value and application prospects. Thus, the method can be used to prepare an anti-radiation deacidification film with excellent deacidification performance and radiation resistance.

[0021] According to the method for preparing the radiation-resistant deacidification film provided by the present invention, in step (1), the ultrasonic treatment time is 20 min-40 min. For example, the ultrasonic treatment time is 20 min, 25 min, 30 min, 35 min, 40 min, etc., or a range between any two of the above values. Controlling the ultrasonic treatment time within the above range can ensure that the graphene oxide and the carbon nanodots fully undergo cross-linking reaction.

[0022] Furthermore, the power of the ultrasonic treatment is 20W-200W.

[0023] In some embodiments of the present invention, the concentration of graphene oxide in the graphene oxide solution is 0.01-1.0 mg / mL, preferably 0.2-0.5 mg / mL; The concentration of the carbon nanodots in the carbon nanodot solution is 0.05-0.25 mg / mL, preferably 0.1-0.15 mg / mL; The concentration of the carboxyl activator in the carboxyl activator solution is 5-25 mg / mL.

[0024] In some embodiments of the present invention, in step (1), the volume of water used is 20 mL-500 mL, preferably 100 mL-300 mL; The added volume of graphene oxide solution is 0.8-5.0 mL, preferably 1.0-2.0 mL; The volume of the carbon nanodot solution added is 50-500µL, preferably 150-300µL; The volume of carboxyl activator solution added is 10-100 µL.

[0025] In some embodiments of the present invention, after the acid-depleting film layer is formed, the acid-depleting film layer is dried and washed.

[0026] In some embodiments of the present invention, in step (2), the drying temperature is 50-90° C., and the drying time is 20 min-60 min.

[0027] In some embodiments of the present invention, in step (2), the dried radiation-resistant deacidified film is soaked in deionized water for washing. Specifically, the soaking and washing can be repeated multiple times, with the deionized water being replaced every 2 hours to 6 hours.

[0028] In some embodiments of the present invention, in step (2), the degree of vacuum used in vacuum filtration and assembly of the membrane slurry on the base membrane is 0.07 MPa.

[0029] In the third aspect of the present invention, the present invention proposes the use of the above-mentioned radiation-resistant acid-removing membrane in reducing the acidity of a high-valent radioactive isotope solution.

[0030] In some embodiments of the present invention, the hydrogen ion concentration in the high-valent radioactive isotope solution is 0.1 mol / L-10 mol / L. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 It is a schematic diagram of the structure of the device used in the present invention to verify the performance of the acid removal membrane; Figure 2 is the La in the deacidification film performance test of Example 1 of the present invention and Comparative Example 1 3+ Comparison chart of diffusion rates; Figure 3 The H in the deacidification film performance test of Example 1 and Comparative Example 1 of the present invention + Comparison chart of diffusion rates; Figure 4 is the La of the deacidified film after irradiation in Example 1 of the present invention 3+ and H + Diagram of the change of diffusion amount over time; Figure 5 The La of the deacidification film before and after irradiation in Example 1 of the present invention is 3+ and H + Comparison of diffusion rates. DETAILED DESCRIPTION

[0033] 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. The present invention is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present invention in any way.

[0034] Example 1 Lanthanum nitrate (La(NO3)3) deacidification experiment. Since La and Ac have similar chemical properties, La is used to simulate the medical isotope in this example. 225 Deacidification process of Ac.

[0035] The graphene oxide used in this embodiment was prepared in the laboratory.

[0036] Carbon nanodots were purchased from Xianfeng Nano Co., Ltd., model number XF353-1.

[0037] The preparation process of the radiation-resistant acid-removing film of this embodiment is as follows: 1.5 mL of 0.1 mg / mL graphene oxide (oxygen content 20%) solution, 100 µL of 0.1 mg / mL carbon nanodots (particle size 4-5 nm) and 50 µL of 20 mg / mL EDC solution were added to 25 mL of deionized water, and diluted to 250 mL after ultrasonic treatment at room temperature at a power of 50 W for 30 min. The diluted solution was filtered on a polytetrafluoroethylene microporous filter membrane with a pore size of 0.45 µm to form a deacidified film layer on the polytetrafluoroethylene microporous filter membrane. The entire deacidified film obtained above was placed in an 80 ° C blast drying oven and dried for 10 min. After naturally cooling to room temperature, it was immersed in deionized water. The deionized water was replaced every 2 to 6 hours. The deacidified film was washed clean and taken out to dry naturally. The thickness of the deacidified film layer in the obtained radiation-resistant deacidified film was 100 nm.

[0038] The difference between the radiation-resistant acid-degradation film of this embodiment and the radiation-resistant acid-degradation film of embodiment 1 is as follows: The thickness of the acid-free film layer in the radiation-resistant acid-free film obtained in Example 2 is 50 nm.

[0039] The difference between the radiation-resistant acid-degradation film of this embodiment and the radiation-resistant acid-degradation film of embodiment 1 is as follows: The thickness of the acid-free film layer in the radiation-resistant acid-free film obtained in Example 3 is 130 nm.

[0040] A commercially available acid removal membrane was used, which was produced in China, model ADM-8040 and brand Huamotech.

[0041] The performance of the acid removal films of the embodiments and comparative examples was tested as follows: (1) Inspection of deacidification performance Prepare lanthanum nitrate solution and equipment. The structure of the experimental equipment is as follows: Figure 1 As shown, the concentration of lanthanum nitrate in the lanthanum nitrate solution is 50 mg / L, and the concentration of hydrogen ions in the lanthanum nitrate solution is 3 mol / L.

[0042] like Figure 1 As shown, the deacidification membrane is sandwiched between two electrolytic cells, and the deacidification membrane layer of the deacidification membrane of the embodiment is placed facing the left electrolytic cell. Then, the above 80 ml lanthanum nitrate solution is added to the left electrolytic cell, and an equal amount of deionized water is added to the right, and the device is placed on a magnetic stirrer for stirring. The pH of the right electrolytic cell is measured 2 h, 5 h, 7 h, ... 48 h from the start of the experiment, and 80 μL of the sample is sampled at the same time to determine the La content in the sample. 3+ concentration.

[0043] The test results of the deacidification membrane performance of the embodiments and comparative examples are shown in Table 1.

[0044] Table 1

[0045] It can be seen from the data in Table 1 that when the deacidification film layer of Example 2 is thinner, compared with the deacidification film of Example 1, the retention of La 3+ The ability to intercept La 3+ The effect is still significantly higher than that of the commercially available deacidification membrane. Compared with Example 1, the thickness of the deacidification membrane of Example 3 is increased. Compared with Example 1, the H + The removal efficiency of La decreased slightly. 3+ The interception capacity is better than that of the commercial deacidification membrane (Comparative Example 1), indicating that the deacidification membrane of the present invention is significantly better than the commercial membrane in the denitration effect of metal ions.

[0046] Can also be combined Figure 2 and Figure 3 , La of Example 1 and Comparative Example 1 3+ and H + The relationship between the diffusion amount and time is as follows Figure 2 and Figure 3 As shown, from Figure 2 and Figure 3 It can be seen that the diffusion rates of the acid-removing membrane of Example 1 of the present invention and the commercially available acid-removing membrane of the comparative example are not much different, but the acid-removing membrane of the present invention has a greater effect on La 3+The diffusion rate is significantly lower than that of the commercial deacidification membrane, indicating that the deacidification membrane of the present invention is significantly better than the commercial membrane in the denitration effect of metal ions.

[0047] (2) Inspection of radiation resistance The deacidification membrane obtained in Example 1 was irradiated with γ-ray for 150 kGy and then subjected to the above-mentioned deacidification experiment of La(NO3)3. The pH and La 3+ The results are shown in Table 2.

[0048] Table 2

[0049] From the data in Table 2, it can be seen that after the deacidification film of Example 1 is irradiated, although the H + Removal efficiency and La 3+ The interception capacity of the present invention is reduced, but compared with the acid-removing membrane of the commercial comparative example 1 which is not irradiated, the acid-removing membrane of the present invention is irradiated. + The removal efficiency decreased, but for La 3+ The interception capacity of the commercially available deacidification membrane of Example 1 which has not been irradiated is not much different. The deacidification membrane of Example 1 after irradiation can still be used to remove high-concentration acid in La(NO3)3 solution, indicating that the deacidification membrane of the present invention has certain radiation resistance and can be used to reduce the acidity of medical radioisotope solution. However, the commercial membrane used in Example 1 becomes fragile after the same dose of irradiation, and breaks into many pieces with a slight touch, so the deacidification experiment cannot be carried out.

[0050] Can also be combined Figure 4 and Figure 5 After irradiation, the deacidified film of Example 1 was La 3+ and H + The relationship between the diffusion amount and time is as follows Figure 4 shown. Figure 5 The La of the deacidification film of Example 1 before and after irradiation 3+ and H + The comparison of diffusion rates shows that the deacidification membrane of Example 1 has a strong effect on H + The diffusion rate is lower than that of the unirradiated deacidified film, La 3+ The diffusion rate is slightly higher. Although the deacidification performance of the deacidification membrane is reduced after irradiation, the deacidification membrane after irradiation can still be used to remove high-concentration acid in La(NO3)3 solution, indicating that the deacidification membrane of the present invention has certain anti-radiation performance and can be used to reduce the acidity of medical radioisotope solution.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A radiation-resistant acid removal film, characterized in that: include: Basement membrane; The acid-deoxidizing film layer is arranged on one side of the base film, and is formed by a cross-linking reaction between graphene oxide and carbon nanodots under the action of a carboxyl activator, and the mass ratio of the graphene oxide to the carbon nanodots is (10-50):

1.

2. The radiation-resistant acid removal film according to claim 1, characterized in that: The particle size of the carbon nanodots is 3nm-7nm.

3. The radiation-resistant acid removal film according to claim 1, characterized in that: The oxygen content of the graphene oxide is 5%-40%.

4. The radiation-resistant acid removal film according to any one of claims 1 to 3, characterized in that: The mass ratio of the graphene oxide to the carboxyl activator is 1:(1-10); And / or, the carboxyl activator is at least one selected from 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, and N,N'-dicyclohexylcarbodiimide.

5. The radiation-resistant acid removal film according to any one of claims 1 to 3, characterized in that: The thickness of the acid-removing film layer is 50nm-150nm.

6. The radiation-resistant acid removal film according to any one of claims 1 to 3, characterized in that: The pore size of the basement membrane is 0.1-200 µm; And / or, the base membrane is selected from one of polytetrafluoroethylene microporous filter membrane, mixed cellulose microporous filter membrane, polypropylene microporous filter membrane and polyvinylidene fluoride microporous filter membrane.

7. A method for preparing the radiation-resistant acid-depleting film according to any one of claims 1 to 6, characterized in that: include: (1) mixing a graphene oxide solution, a carbon nanodot solution and a carboxyl activator solution in water and then ultrasonically treating the mixture at room temperature to obtain a membrane slurry; (2) The membrane layer slurry is vacuum filtered and assembled on the base membrane to form a deacidified membrane layer.

8. The method according to claim 7, characterized in that: In step (1), the ultrasonic treatment time is 5 min to 40 min; And / or, the power of the ultrasonic treatment is 20W-200W.

9. Use of the radiation-resistant acid-removing film according to any one of claims 1 to 6 in reducing the acidity of a high-valent radioactive isotope solution.

10. The use according to claim 9, characterized in that: The hydrogen ion concentration in the high-valent radioactive isotope solution is 0.1 mol / L-10 mol / L.

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