Preparation method and application of PAM / PB / PAO dual-network hydrogel adsorption material with flexibility and uranium adsorption selectivity

Abstract

The invention relates to a preparation method and application of a PAM / PB / PAO dual-network hydrogel adsorption material with flexibility and uranium adsorption selectivity. The invention relates to a preparation method and application of a PAM / PB / PAO dual-network hydrogel adsorption material. The technical problems that an existing hydrogel uranium adsorption material is poor in mechanical property, uneven in functional group distribution, low in adsorption selectivity in an actual complex water body and insufficient in cycling stability are solved. The method comprises the following steps: carrying out radiation crosslinking treatment to obtain PAM / PB / PAN composite hydrogel; and carrying out amidoximation reaction to obtain the PAM / PB / PAO dual-network hydrogel adsorption material. The material has excellent anti-fatigue property, high adsorption capacity and good cycle stability, and shows remarkable adsorption selectivity on uranyl ions in the presence of various competitive ions. The PAM / PB / PAO dual-network hydrogel adsorption material with flexibility and uranium adsorption selectivity prepared by the invention is applied to the field of uranium adsorption in radioactive waste liquid.

Description

Technical Field

[0001] This invention relates to a method for preparing PAM / PB / PAO dual-network hydrogel adsorbent materials and their applications. Background Technology

[0002] In the treatment of radioactive waste liquids in the nuclear industry, the efficient adsorption and resource recovery of uranium is of great significance. Adsorption methods are widely used due to their advantages of simple operation and low cost. However, traditional powder or particulate adsorption materials have problems such as difficult recovery, poor mechanical strength, and low selectivity for uranium adsorption in complex water bodies. Although hydrogel materials have three-dimensional network structures and functionalization potential, conventional single-network hydrogels have poor mechanical properties, are prone to structural damage in the swollen state, and lack functional groups that specifically chelate uranyl ions, limiting their long-term use under actual working conditions.

[0003] Currently, although studies have explored ways to improve the mechanical properties of hydrogels through dual-network structures or nanocomposites, or to introduce amine oxime groups to enhance the selective adsorption capacity for uranium, challenges remain, including complex preparation processes, uneven distribution of functional groups, and difficulties in synergistically optimizing mechanical stability and adsorption performance. For example, existing dual-network hydrogels still exhibit insufficient modulus under high pressure, while traditional chemical grafting methods easily damage the integrity of the gel network, affecting the material's cycle life. Therefore, developing a hydrogel uranium adsorption material that combines high mechanical strength, excellent adsorption selectivity, good structural stability, and easy recyclability has become a pressing technical challenge in this field. Summary of the Invention

[0004] This invention provides a method for preparing a PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity, and its application. It solves the technical problems of poor mechanical properties, uneven distribution of functional groups, low adsorption selectivity and insufficient cycle stability of existing hydrogel uranium adsorbent materials in actual complex water bodies.

[0005] A method for preparing a PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity, specifically comprising the following steps:

[0006] 1. Acrylamide is dissolved in deionized water, acrylonitrile monomer is added, and after being magnetically stirred and dispersed evenly, pre-irradiated polybutadiene nano-rubber emulsion is added and stirred for 1-5 hours. Then, ultrasonic emulsification is performed to form a stable prepolymer system mixed solution. The mixed solution is placed in a γ-ray irradiation device for radiation crosslinking treatment to obtain PAM / PB / PAN composite hydrogel.

[0007] 2. After the PAM / PB / PAN composite hydrogel obtained in step 1 is swollen and equilibrated, it is added to a weakly alkaline solution containing hydroxylamine hydrochloride and subjected to a amine oxime reaction at a temperature of 60~80 ℃ for 2~48 h. The resulting product is washed with deionized water and then soaked in a large amount of deionized water to obtain the PAM / PB / PAO dual-network hydrogel adsorbent material.

[0008] Furthermore, the mass percentage of the acrylamide after dissolution in step one is 30%.

[0009] Furthermore, the mass percentage of the polybutadiene nano-rubber emulsion in step one is 42%; the irradiation dose of the pre-irradiation treatment of the polybutadiene nano-rubber emulsion is 10~300 kGy, and the irradiation time is 2~600 h.

[0010] Furthermore, the mass ratio of acrylamide to acrylonitrile monomer in step one is (7.5~5.0):(0.5~3.0); the mass ratio of polybutadiene nano-rubber to acrylamide is (5~100):50.

[0011] Furthermore, the irradiation crosslinking dose of the mixed solution in step one is 5~150 kGy, and the irradiation time is 5~300 h.

[0012] Furthermore, the weakly alkaline solution containing hydroxylamine hydrochloride mentioned in step two is a mixture of hydroxylamine hydrochloride and a weakly alkaline solution, and then the pH is adjusted to 6-9 using an alkaline solution.

[0013] The weakly alkaline solution is an aqueous solution of one or more of DMSO, DMF, CH3OH and CH3CH2OH; the mass concentration of hydroxylamine hydrochloride is 5-10%.

[0014] Furthermore, the alkaline solution is one or a mixture of several of Na2CO3, NaHCO3, NaOH, and triethylamine.

[0015] The aforementioned PAM / PB / PAO dual-network hydrogel adsorbent material, which possesses flexibility and uranium adsorption selectivity, is used as an adsorbent for the adsorption of uranium in radioactive waste liquid.

[0016] The application method is as follows:

[0017] The PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity was added to radioactive waste liquid at a solid-liquid ratio of 0.6 g / L, and the pH of the radioactive waste liquid was controlled at 2.0~7.0. Adsorption was carried out under the conditions of oscillation at a treatment temperature of 25℃ and a rotation speed of 150 r / min.

[0018] This method is applicable to uranium-containing radioactive waste liquids with a uranium concentration of 50~500 mg / L.

[0019] The material described in this invention employs a synergistic strategy of radiation-initiated graft polymerization and amylopyridine modification, using acrylamide as the matrix, polybutadiene nanorubber as the toughening phase, and acrylonitrile as the amylopyridine precursor to construct a three-dimensional dual-network structure that combines excellent mechanical properties with efficient adsorption function.

[0020] Beneficial effects of this invention:

[0021] This invention employs a synergistic strategy of radiation-initiated graft polymerization and cyanohydroxylamine method to construct a dual-network structure of polyacrylamide matrix / nanopolybutadiene rubber toughening phase / polyamine oxime functional phase, achieving dual optimization of material mechanical properties and adsorption function. This material exhibits excellent fatigue resistance, high adsorption capacity, and good cycling stability, demonstrating significant adsorption selectivity for uranyl ions in the presence of multiple competing ions. It solves the technical problems of traditional uranium adsorbent materials, such as easy structural collapse, poor mechanical properties, low adsorption efficiency, and insufficient recyclability in complex fluid environments.

[0022] (1) The double network structure is constructed by one-step γ-ray radiation, which avoids initiator residue, and the process is green and efficient, suitable for large-scale preparation.

[0023] (2) By introducing a nano-rubber toughening phase and a amine oxime functional phase, the material's mechanical properties (compression strength retention rate >90% after 30 cycles of 80% strain) and adsorption capacity (763.40 mg·g) were achieved. -1 ) to achieve synergistic improvement.

[0024] (3) The material exhibits excellent selective adsorption and cycling stability, with a partition coefficient as high as 13750.90 mL·g under the presence of multiple competing ions. -1 The efficiency retention rate exceeded 91.10% after 4 adsorption-desorption cycles.

[0025] (4) This invention provides a novel material solution that combines flexibility, functionality and engineering for the efficient recovery of uranium in complex radiation environments.

[0026] The PAM / PB / PAO dual-network hydrogel adsorbent material prepared by this invention, which has flexibility and uranium adsorption selectivity, is applied in the field of uranium adsorption in radioactive waste liquid. Attached Figure Description

[0027] Figure 1 This is the preparation process of Example 1 and the adsorption mechanism diagram of the obtained PAM / PB / PAO dual-network hydrogel adsorption material;

[0028] Figure 2These are the infrared spectra of PAM / PB / PAN and PAM / PB / PAO before and after the reaction with the amine oxime in Example 1.

[0029] Figure 3 This is a scanning electron microscope image of the surface of the PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1;

[0030] Figure 4 This is the compressive strength-strain diagram (ε=80%) of the PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1 after 30 cycles of compression.

[0031] Figure 5 This is a graph showing the effect of uranium solution pH on the adsorption capacity of the PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1.

[0032] Figure 6 The graph shows the effect of adsorption time on the adsorption capacity of the PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1.

[0033] Figure 7 The adsorption isotherm diagram is shown for the PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1.

[0034] Figure 8 The graph shows the effect of competing ions on the adsorption capacity of the PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1.

[0035] Figure 9 The graph shows the adsorption / desorption efficiency of the PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1 after 4 cycles.

[0036] Figure 10 The graph shows a comparison of the adsorption performance of the PAM / PB / PAO dual-network hydrogel adsorbent materials prepared in Example 1, Example 2, Example 3, Example 4, and Example 5. Detailed Implementation

[0037] Specific Implementation Method 1: This implementation method describes a preparation method for a PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity, specifically carried out according to the following steps:

[0038] 1. Acrylamide is dissolved in deionized water, acrylonitrile monomer is added, and after being magnetically stirred and dispersed evenly, pre-irradiated polybutadiene nano-rubber emulsion is added and stirred for 1-5 hours. Then, ultrasonic emulsification is performed to form a stable prepolymer system mixed solution. The mixed solution is placed in a γ-ray irradiation device for radiation crosslinking treatment to obtain PAM / PB / PAN composite hydrogel.

[0039] 2. After the PAM / PB / PAN composite hydrogel obtained in step 1 is swollen and equilibrated, it is added to a weakly alkaline solution containing hydroxylamine hydrochloride and subjected to a amine oxime reaction at a temperature of 60~80 ℃ for 2~48 h. The resulting product is washed with deionized water and then soaked in a large amount of deionized water to obtain the PAM / PB / PAO dual-network hydrogel adsorbent material.

[0040] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the mass percentage of acrylamide after dissolution in step one is 30%. Everything else is the same as in Specific Implementation Method One.

[0041] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that: the mass percentage of the polybutadiene nano-rubber latex in step one is 42%; the irradiation dose of the pre-irradiation treatment of the polybutadiene nano-rubber latex is 10~300 kGy, and the irradiation time is 2~600 h. Everything else is the same as in Specific Implementation Method One or Two.

[0042] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that: the mass ratio of acrylamide to acrylonitrile monomer in step one is (7.5~5.0):(0.5~3.0); the mass ratio of polybutadiene nano-rubber to acrylamide is (5~100):50. Everything else is the same as in Specific Implementation Methods One to Three.

[0043] Specific Implementation Method Five: This implementation method differs from one of Specific Implementation Methods One to Four in that the irradiation crosslinking dose of the mixed solution in step one is 5~150 kGy, and the irradiation time is 5~300 h. Everything else is the same as in one of Specific Implementation Methods One to Four.

[0044] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that: the weakly alkaline solution containing hydroxylamine hydrochloride mentioned in step two is a mixture of hydroxylamine hydrochloride and a weakly alkaline solution, and then the pH is adjusted to 6-9 using an alkaline solution;

[0045] The weakly alkaline solution is an aqueous solution of one or more of DMSO, DMF, CH3OH, and CH3CH2OH; the mass concentration of hydroxylamine hydrochloride is 5-10%. Other aspects are the same as in any one of embodiments one to five.

[0046] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that the alkaline solution is one or a mixture of several of Na₂CO₃, NaHCO₃, NaOH, and triethylamine. Everything else is the same as in Specific Implementation Methods One to Six.

[0047] Specific Implementation Method 8: In this implementation method, a PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity is used as an adsorbent for the adsorption of uranium in radioactive waste liquid.

[0048] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method Eight in that: the application method of a PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity is as follows:

[0049] The PAM / PB / PAO dual-network hydrogel adsorbent material, which exhibits flexibility and uranium adsorption selectivity, was added to the radioactive waste liquid at a solid-liquid ratio of 0.6 g / L. The pH of the radioactive waste liquid was controlled at 2.0–7.0, and adsorption was carried out under oscillation conditions at a treatment temperature of 25°C and a rotation speed of 150 r / min. Other procedures were the same as in Specific Embodiment Eight.

[0050] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods Eight or Nine in that it is applied to uranium-containing radioactive waste liquid with a uranium concentration of 50-500 mg / L. Everything else is the same as in Specific Implementation Methods Eight or Nine.

[0051] The scope of this invention is not limited to the above-described embodiments; a combination of one or more specific embodiments can also achieve the purpose of the invention.

[0052] Example 1:

[0053] This embodiment describes a method for preparing a PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity, which is carried out according to the following steps:

[0054] 1. Acrylamide was dissolved in deionized water to a mass percentage of 30%. Acrylonitrile monomer was added at a mass ratio of 5:0.5. After being magnetically stirred and dispersed evenly, 42% pre-irradiated polybutadiene nano-rubber emulsion was added. The irradiation dose of the pre-irradiated polybutadiene nano-rubber emulsion was 200 kGy, and the mass ratio of polybutadiene nano-rubber to acrylamide was 25:50. The mixture was stirred for 3 hours and then ultrasonically emulsified to form a stable prepolymer system. The mixed solution was placed in a gamma-ray irradiation device for radiation crosslinking treatment at a dose of 10 kGy for 10 hours to obtain a PAM / PB / PAN composite hydrogel.

[0055] 2. After the PAM / PB / PAN composite hydrogel obtained in step 1 is swollen and equilibrated, it is added to a weakly alkaline solution containing hydroxylamine hydrochloride. The weakly alkaline solution containing hydroxylamine hydrochloride is a mixture of hydroxylamine hydrochloride and a weakly alkaline solution. Then, the pH is adjusted to 7.5 with triethylamine. The weakly alkaline solution is a mixture of CH3OH and H2O in a volume ratio of 1:1, and the mass concentration of hydroxylamine hydrochloride is 5%. The amylated reaction is carried out at a temperature of 70℃ for 6 h. The resulting product is washed 5 times with deionized water and then soaked in a large amount of deionized water for 24 h to obtain the PAM / PB / PAO dual-network hydrogel adsorbent material.

[0056] Example 2:

[0057] The difference between this embodiment and Example 1 is that the mass ratio of acrylamide to acrylonitrile monomer in step one is 5:1. Everything else is the same as in Example 1.

[0058] Example 3:

[0059] The difference between this embodiment and Example 1 is that the mass ratio of acrylamide to acrylonitrile monomer in step one is 5:1.5. Everything else is the same as in Example 1.

[0060] Example 4:

[0061] The difference between this embodiment and Embodiment 1 is that the irradiation dose of the polybutadiene nano-rubber emulsion pre-irradiation treatment in step one is 100 kGy, and the mass ratio of polybutadiene nano-rubber to acrylamide is 15:50. Everything else is the same as in Embodiment 1.

[0062] Example 5:

[0063] The difference between this embodiment and Embodiment 1 is that the irradiation crosslinking dose in step two is 20 kGy, and the irradiation time is 40 h. Everything else is the same as in Embodiment 1.

[0064] Example 6:

[0065] The difference between this embodiment and Embodiment 1 is that in step one, the mixed solution is placed in a gamma-ray irradiation device for radiation crosslinking treatment. The irradiation crosslinking dose is 40 kGy, and the irradiation time is 40 h. Everything else is the same as in Embodiment 1.

[0066] Example 7:

[0067] The difference between this embodiment and Embodiment 1 is that in step one, the mixed solution is placed in a gamma-ray irradiation device for radiation crosslinking treatment, and the irradiation crosslinking dose is 15 kGy. Everything else is the same as in Embodiment 1.

[0068] Example 8:

[0069] The difference between this embodiment and Embodiment 1 is that the weakly alkaline solution in step two is an aqueous solution of DMSO and DMF, with a total volume ratio of DMSO and DMF to H2O of 1:1. Everything else is the same as in Embodiment 1.

[0070] Example 9:

[0071] The difference between this embodiment and Embodiment 1 is that NaHCO3 is used to adjust the pH in step two. Everything else is the same as in Embodiment 1.

[0072] Example 10:

[0073] The difference between this embodiment and Embodiment 1 is that the pH value in step two is 6.0. Everything else is the same as in Embodiment 1.

[0074] Example 11:

[0075] The difference between this embodiment and Example 1 is that the reaction temperature for step two, the oximeization of the amine, is 60°C. Everything else is the same as in Example 1.

[0076] Example 12:

[0077] The difference between this embodiment and Example 1 is that the reaction time for step two, the oxime oxidation, is 4 hours. Everything else is the same as in Example 1.

[0078] Figure 1 This is the preparation process of Example 1 and the adsorption mechanism diagram of the obtained PAM / PB / PAO dual-network hydrogel adsorbent material.

[0079] Figure 2 This is the infrared spectrum of PAM / PB / PAN and PAM / PB / PAO before and after the amine oxime reaction in Example 1; the 2245 cm⁻¹ value of PAM / PB / PAN and PAM / PB / PAO in the figure is shown. -1 The peak at 1640 cm⁻¹ is a characteristic peak for -CN, which disappears after the addition of a amine oxime. In the infrared spectrum of PAM / PB / PAO, the peak is at 1640 cm⁻¹. -1 1027cm -1 and 936cm -1 The appearance of new characteristic peaks at the point is attributed to the stretching vibrations of C=N, CN, and NO, respectively, indicating that the amylopyroxylation reaction was successful and that amylopyroxyroxy groups are present on the surface of the adsorbent material.

[0080] Figure 3 This is a scanning electron microscope image of the surface of the PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1. PAM / PB / PAO has a three-dimensional porous structure, which helps uranyl ions in the solution to fully contact with surface active groups, thereby improving adsorption performance.

[0081] Figure 4This is the compressive strength-strain curve of the PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1 after 30 cycles of compression; the curve (ε=80%) is derived from... Figure 4 It can be seen that the PAM / PB / PAO uranium adsorbent material retains more than 90% of its compressive strength after 30 cycles of 80% strain.

[0082] Uranium adsorption performance test of the PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1.

[0083] The PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1 was applied to uranium adsorption testing in water. The specific process is as follows:

[0084] Batch experiments were conducted under the conditions of uranium solution concentration of 100 mg / L, solid-liquid ratio of 0.25 g / L, and temperature of 25℃, within a pH range of 2.0 to 6.0. The adsorption capacity of uranyl ions was measured and calculated using a UV spectrophotometer, and the effect of pH on the adsorption capacity of PAM / PB / PAO was analyzed. Figure 5 As the pH increases from 2.0 to 5.5, the adsorption capacity of PAM / PB / PAO for uranyl ions gradually increases. As the pH continues to increase, the adsorption capacity decreases. Therefore, the preferred pH for uranium adsorption testing is 5.5.

[0085] Under the conditions of uranium solution concentration of 100 mg / L, solid-liquid ratio of 0.25 g / L, pH of 5.5, and temperature of 25℃, the effect of adsorption time on the adsorption capacity of PAM / PB / PAO was tested by controlling the adsorption time at 10 min, 20 min, 60 min, 90 min, 120 min, 150 min, 180 min, 240 min, 420 min, and 600 min.

[0086] Figure 6 The graph shows the effect of adsorption time on the adsorption capacity of the PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1. The results show that the adsorbent in Example 1 has a high adsorption efficiency for uranium, with rapid adsorption occurring within 90 min and reaching adsorption equilibrium at 420 min.

[0087] Under the conditions of a solid-liquid ratio of 0.25 g / L, pH of 5.5, adsorption time of 420 min, and temperature of 25℃, the uranium solution concentration was adjusted to 5 mg·L⁻¹. -1 20 mg·L -1 30 mg·L -1 50 mg·L -1 80 mg·L -1 120 mg·L -1 200 mg·L -1 250 mg·L-1 350 mg·L -1 Calculate the adsorption capacity of the adsorbent under different uranium solution concentrations.

[0088] Figure 7 The adsorption isotherm diagram of the PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1 is shown. The isotherm was fitted and analyzed, and it conforms to the Langumir model. The maximum adsorption capacity calculated by the fitting was 763.40 mg / g, indicating that the adsorbent adsorbs uranyl ions mainly through monolayer chemisorption and has a high adsorption capacity.

[0089] A mixed solution of CaCl2, MgCl2, K2(SO4)2, Ni(NO3)2, Cu(NO3)2, NaNO3, ZnCl2, and UO2(NO3)2·6H2O with a concentration of 100 mg / L was prepared, and the pH of the solution was adjusted to 5.5. 20 mL of the above solution was transferred to a 50 mL centrifuge tube, and 10 mg of adsorbent (the PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1) was added. The tube was shaken at 298 K for 18 h. After adsorption was complete, the supernatant was collected, and the concentrations of uranyl ions and other metal cations in the supernatant were measured by ICP-MS. The adsorption capacity and adsorption efficiency of the adsorbent for these ions were calculated.

[0090] Figure 8 The figure shows the effect of competing ions on the adsorption capacity of the PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1. As can be seen from the figure, among the many ions, the adsorbent's adsorption capacity for uranium is much greater than that for other metal ions, with a partition coefficient as high as 13750.90 mL·g under the presence of multiple competing ions. -1 This indicates that the PAM / PB / PAO dual-network hydrogel adsorbent material has excellent adsorption selectivity.

[0091] Weigh 10 mg of the adsorbent material (the PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1) and add it to a solution with a concentration of 100 mg·L⁻¹. -1 The uranium solution was adjusted to pH 5.5 and placed in a constant temperature water bath shaker at 298 K and 150 rpm for 18 h to allow adsorption to complete. The adsorption capacity was then tested, and the adsorption efficiency was calculated. The filtered adsorbent was then added to a solution with a concentration of 0.5 mol·L⁻¹. -1 Na₂CO₃ solution or 0.1 mol·L⁻¹ -1 The solution was shaken in an HNO3 desorption solution at a constant temperature of 298 K for 18 hours. After desorption was complete, the uranium ion concentration in the solution was measured by ICP-MS, and the desorption efficiency was calculated. The above operation was repeated several times until the adsorption efficiency of the adsorbent material decreased significantly.

[0092] Figure 9 The graph shows the adsorption-desorption efficiency of the PAM / PB / PAO dual-network hydrogel adsorbent material prepared in Example 1 after 4 adsorption-desorption cycles. The results show that the efficiency retention rate of the PAM / PB / PAO dual-network hydrogel adsorbent material after 4 adsorption-desorption cycles exceeds 91.10%.

[0093] The adsorption capacity of the adsorbent material was tested under the following conditions: uranium solution concentration of 100 mg / L, solid-liquid ratio of 0.25 g / L, pH of 5.5, adsorption time of 420 min, and temperature of 25℃. Figure 10 The graph shows a comparison of the adsorption performance of the PAM / PB / PAO dual-network hydrogel adsorbent materials prepared in Example 1, Example 2, Example 3, Example 4, and Example 5. The results show that the saturated adsorption capacity of the adsorbent materials prepared in Example 3, Example 4, and Example 5 is lower than that of Example 1.

Claims

1. A method for preparing a PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity, characterized in that... This method is specifically carried out in the following steps:

1. Acrylamide is dissolved in deionized water, acrylonitrile monomer is added, and after being magnetically stirred and dispersed evenly, pre-irradiated polybutadiene nano-rubber emulsion is added and stirred for 1-5 hours. Then, ultrasonic emulsification is performed to form a stable prepolymer system mixed solution. The mixed solution is placed in a γ-ray irradiation device for radiation crosslinking treatment to obtain PAM / PB / PAN composite hydrogel.

2. After the PAM / PB / PAN composite hydrogel obtained in step 1 is swollen and equilibrated, it is added to a weakly alkaline solution containing hydroxylamine hydrochloride and subjected to a amine oxime reaction at a temperature of 60~80 ℃ for 2~48 h. The resulting product is washed with deionized water and then soaked in a large amount of deionized water to obtain the PAM / PB / PAO dual-network hydrogel adsorbent material.

2. The method for preparing a PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity according to claim 1, characterized in that... The mass percentage of acrylamide after dissolution in step one is 30%.

3. The method for preparing a PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity according to claim 1, characterized in that... The mass percentage of the polybutadiene nano-rubber emulsion in step one is 42%; the irradiation dose of the polybutadiene nano-rubber emulsion pre-irradiation treatment is 10~300 kGy, and the irradiation time is 2~600 h.

4. The method for preparing a PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity according to claim 1, characterized in that... The mass ratio of acrylamide to acrylonitrile monomer in step one is (7.5~5.0):(0.5~3.0); the mass ratio of polybutadiene nano-rubber to acrylamide is (5~100):

50.

5. The method for preparing a PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity according to claim 1, characterized in that... The irradiation crosslinking dose of the mixed solution in step one is 5~150 kGy, and the irradiation time is 5~300 h.

6. The method for preparing a PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity according to claim 1, characterized in that... The weakly alkaline solution containing hydroxylamine hydrochloride mentioned in step two is a mixture of hydroxylamine hydrochloride and a weakly alkaline solution, and then the pH is adjusted to 6-9 using an alkaline solution; The weakly alkaline solution is an aqueous solution of one or more of DMSO, DMF, CH3OH and CH3CH2OH; the mass concentration of hydroxylamine hydrochloride is 5-10%.

7. The method for preparing a PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity according to claim 6, characterized in that... The alkaline solution is one or a mixture of several of Na2CO3, NaHCO3, NaOH and triethylamine.

8. The application of the PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity prepared according to claim 1, characterized in that... The aforementioned PAM / PB / PAO dual-network hydrogel adsorbent material, which possesses flexibility and uranium adsorption selectivity, is used as an adsorbent for the adsorption of uranium in radioactive waste liquid.

9. The application of the PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity according to claim 8, characterized in that... The application method is as follows: The PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity was added to radioactive waste liquid at a solid-liquid ratio of 0.6 g / L, and the pH of the radioactive waste liquid was controlled at 2.0~7.

0. Adsorption was carried out under the conditions of oscillation at a treatment temperature of 25℃ and a rotation speed of 150 r / min.

10. The application of the PAM / PB / PAO dual-network hydrogel adsorbent material with flexibility and uranium adsorption selectivity according to claim 9, characterized in that... This method is applicable to uranium-containing radioactive waste liquids with uranium concentrations of 50–500 mg / L.

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