Temperature response type europium ion imprinting composite membrane preparation method and application

[0047] Example 1

[0048] (1) Surface modification of regenerated cellulose membrane

[0049] First, place 0.1211g Tris and 0.2g DA in 100mL deionized water, mix thoroughly under ultrasonic conditions, adjust the pH to 8.5 to obtain a mixed solution, immerse 3 pieces of RCMs in the mixed solution, and react for 0 hours under room temperature shaking to obtain the modified For supporting membrane dRCMs, take out the modified supporting membrane, soak and wash it with deionized water three times for 10 minutes each time, and dry the cleaned modified supporting membrane at room temperature.

[0050] (2) Preparation of non-self-supporting graphene oxide composite film

[0051] First, add 0.5g of silica nanospheres with a diameter of ~300nm to a mixed solution of 100mL of ethanol and water (ethanol:water=4:1), add 3mL of KH-570 after 5 minutes of nitrogen flow, and seal with degreasing tape. React at 80°C for 16 hours. After centrifugation, the product (kSiO2) is washed with alcohol and water for three times. 2 Drying; weigh 5mg of dried kSiO 2 Placed in 50mL deionized water and mixed thoroughly with ultrasound to obtain kSiO with a concentration of 100mg/L 2 Solution, put 5mg GO in 50mL deionized water, mix thoroughly with ultrasound to obtain a GO solution with a concentration of 100mg/L, respectively measure 5mL kSiO 2 The solution and 5mL GO solution were mixed and mixed uniformly under ultrasonic conditions. The solids in the mixed solution were suction filtered onto dRCMs under a vacuum pressure of 0.07MPa to obtain non-self-supporting graphene oxide composite membrane CMs. The CMs were dried at room temperature dry.

[0052] (3) Preparation of temperature-responsive europium ion-imprinted composite membrane

[0053] First, 8mL of a tetrahydrofuran solution with a concentration of 1mol/L phenylmagnesium bromide was heated to 40℃ under the protection of nitrogen, and 0.6mL CS was slowly added dropwise with a syringe. 2 , Keep the temperature at 40℃ for 1 hour under the protection of nitrogen, add 1.1mLC dropwise with a syringe 7 H 7 Br, heated to 50°C for 2 hours under the protection of nitrogen, cool the product naturally to room temperature, add 30mL deionized water, extract with 30mL petroleum ether with a boiling range of bp90~120°C and retain the organic phase to obtain chain transfer reagent CTA; 0.025g EuCl 3 • 6H 2 O, 0.1mmol Am, 0.1mmol NIPAm, and 2mmol EGDMA were added to 60mL of acetonitrile. The solution was mixed uniformly under ultrasonic conditions, and 3 pieces of CMs were added to the above mixed solution. Nitrogen was added to the solution for 10 minutes. Under nitrogen, add 30μL of the prepared CTA and 50mg AIBN to the solution, continue nitrogen flow for 10 minutes, then seal with vacuum glass stopper, degreasing tape and cling film, heat up the reactant to 50℃ and maintain it for 6 hours to make the reactant proceed. After pre-polymerization, the reactants were heated to 60°C, and the reactants were subjected to imprinting polymerization for 12 hours. The product film was taken out and soaked in ethanol for three times for 10 minutes each time, and then washed and soaked three times in deionized water each time. After 10 minutes, dry at room temperature to obtain the imprinted composite membrane; place 3 pieces of the obtained imprinted composite membrane in 200mL of 1mol/L hydrochloric acid solution to elute template ions, and replace the hydrochloric acid solution every 6 hours, the elution process For three days, the eluted membrane was taken out and dried at room temperature to obtain a temperature-responsive europium ion imprinted composite membrane Eu-IIMs-1.

[0054] (4) Static adsorption experiment

[0055] Weigh 5 parts of Eu-IIMs and Eu-NIMs respectively, put them into 10 glass test tubes, and add 10 mL of EuCl with concentrations of 5, 10, 25, 50, 100 mg/L. 3 The aqueous solution is shaken in a constant temperature water bath at 25°C for 3 hours. After the adsorption is completed, the concentration of unadsorbed europium ions in the original solution is measured by ICP, and the adsorption capacity is calculated based on the result.

[0056] The results show that the highest saturated adsorption capacity of IIMs is 41.06 mg/g, which is significantly higher than the 18.22 mg/g of NIMs.

[0057] (5) Selective adsorption experiment

[0058] Weigh 5 parts of Eu-IIMs, put them into 5 glass test tubes, and add 10 mL of 5, 10, 25, 50, 100 mg/L mixed aqueous solution containing the same concentration of europium ions, lanthanum ions, and gadolinium ions. Shake in a constant temperature water bath at 25°C for 3 hours. After the adsorption is completed, the concentration of unadsorbed europium ions in the original solution is determined by ICP, and the adsorption capacity is calculated based on the result.

[0059] The results showed that the highest saturated adsorption capacity of Eu-IIMs for europium ions in competitive adsorption was 41.06 mg/g, and the highest saturated adsorption capacities for lanthanum and gadolinium ions were 14.32 mg/g and 18.33 mg/g, respectively. The selection factors were respectively Are 2.87 and 2.24.

[0060] (6) Selective permeability experiment

[0061] Self-made combined H-shaped glass permeation device, the middle is disconnected into two grinding mouth branch pipes, Eu-IIMs or Eu-NIMs are fixed between the grinding mouths of the two glass tanks, and the connection is sealed with degreasing tape and waterproof tape to ensure that the device is free from leakage To leak, add a mixed aqueous solution of europium chloride, lanthanum nitrate and gadolinium nitrate with the same ion concentration in one sample cell, add an equal volume of deionized water to the other sample cell, put a magnet in each of the two sample cells, The device is placed in a constant temperature water bath and stirred at 25°C. The ion concentration through the imprinted composite membrane is measured by ICP, and the permeation amount is calculated based on this.

[0062] Eu-IIMs selective permeation experiment results show that the sampling times are 5, 10, 15, 30, 45, 60, 90, 120 in a mixed aqueous solution with the initial concentrations of europium, lanthanum, and gadolinium ions all being 100 mg/L. At 180 minutes, the europium ion concentration in the blank sample cell was 0.027, 0.261, 0.343, 0.527, 0.616, 0.792, 0.838, 0.950, 0.931 mg/L, and the lanthanum ion concentration was 0.026, 0.230, 0.363, 0.584, 0.652, 0.781, 0.856, 0.940, 0.984 mg/L, the measured gadolinium ion concentrations were 0.028, 0.229, 0.358, 0.579, 0.630, 0.785, 0.864, 0.983, 0.971 mg/L.

[0063] Eu-NIMs selective permeation experiment results show that the sampling time is 5, 10, 15, 30, 45, 60, 90, 120 in a mixed aqueous solution with the initial concentration of europium ion, lanthanum ion, and gadolinium ion at 100 mg/L. At 180 minutes, the europium ion concentration in the blank sample cell was 0.068, 0.279, 0.398, 0.597, 0.679, 0.790, 0.901, 0.937, 1.210 mg/L, and the lanthanum ion concentration was 0.072, 0.281, 0.384, 0.583, 0.680, 0.814, 0.897, 0.914, 1.205 mg/L, and the measured gadolinium ion concentrations were 0.064, 0.273, 0.392, 0.591, 0.685, 0.795, 0.882, 0.928, 1.197 mg/L, respectively.

[0065] Example 2

[0066] (1) Surface modification of regenerated cellulose membrane

[0067] First, place 0.1211g Tris and 0.2g DA in 100mL deionized water, mix thoroughly under ultrasonic conditions and adjust the pH to 8.5 to obtain a mixed solution. Immerse 3 pieces of RCMs in the mixed solution and react for 3 hours under room temperature shaking to obtain the modified solution. For supporting membrane dRCMs, take out the modified supporting membrane, soak and wash it with deionized water three times for 10 minutes each time, and dry the cleaned modified supporting membrane at room temperature.

[0068] (2) Preparation of non-self-supporting graphene oxide composite film

[0069] First, add 0.5g of silica nanospheres with a diameter of ~300nm to a mixed solution of 100mL of ethanol and water (ethanol:water=4:1), add 3mL of KH-570 after 5 minutes of nitrogen flow, and seal with degreasing tape. React at 80°C for 16 hours. After centrifugation, the product (kSiO2) is washed with alcohol and water for three times. The kSiO2 is washed under vacuum at 40°C. 2 Drying; weigh out 5mg of dried kSiO 2 Placed in 50mL deionized water and mixed thoroughly with ultrasound to obtain kSiO with a concentration of 100mg/L 2 Solution, put 5mg GO in 50mL deionized water, mix thoroughly with ultrasound to obtain a GO solution with a concentration of 100mg/L, respectively measure 5mL kSiO 2 The solution and 5mL GO solution were mixed, mixed uniformly under ultrasonic conditions, and the solids in the mixed solution were suction filtered onto dRCMs under a vacuum pressure of 0.07MPa to obtain non-self-supporting graphene oxide composite film CMs. The CMs were dried at room temperature dry.

[0070] (3) Preparation of temperature-responsive europium ion-imprinted composite membrane

[0071] First, 8mL of a tetrahydrofuran solution with a concentration of 1mol/L phenylmagnesium bromide was heated to 40℃ under the protection of nitrogen, and 0.6mL CS was slowly added dropwise with a syringe. 2 , Keep the temperature at 40℃ for 1 hour under the protection of nitrogen, add 1.1mLC dropwise with a syringe 7 H 7 Br, heated to 50°C for 2 hours under the protection of nitrogen, cool the product naturally to room temperature, add 30mL deionized water, extract with 30mL petroleum ether with a boiling range of bp90~120°C and retain the organic phase to obtain chain transfer reagent CTA; add 0.05gEuCl 3 • 6H 2 O, 0.2mmol Am, 0.2mmol NIPAm, 4mmol EGDMA were added to 60mL of acetonitrile, the solution was mixed uniformly under ultrasonic conditions, 3 pieces of CMs were added to the above mixed solution, nitrogen was added to the solution for 10 minutes, while maintaining continuous flow Under nitrogen, add 30μL of the prepared CTA and 50mg AIBN to the solution, continue nitrogen flow for 10 minutes, then seal with vacuum glass stopper, degreasing tape and cling film, heat up the reactant to 50℃ and maintain it for 6 hours to make the reactant proceed. After pre-polymerization, the reactants were heated to 60°C, and the reactants were subjected to imprinting polymerization for 24 hours. The product film was taken out and soaked in ethanol for three times for 10 minutes each time, and then washed and soaked three times in deionized water each time. After 10 minutes, dry at room temperature to obtain the imprinted composite membrane; place 3 pieces of the obtained imprinted composite membrane in 200mL of 1mol/L hydrochloric acid solution to elute template ions, and replace the hydrochloric acid solution every 6 hours. The elution process For three days, the eluted membrane was taken out and dried at room temperature to obtain a temperature-responsive europium ion imprinted composite membrane Eu-IIMs-2.

[0072] (4) Static adsorption experiment

[0073] Weigh 5 parts of Eu-IIMs and Eu-NIMs respectively, put them into 10 glass test tubes, and add 10 mL of EuCl with concentrations of 5, 10, 25, 50, 100 mg/L. 3 The aqueous solution was shaken in a constant temperature water bath at 35°C for 3 hours. After the adsorption was completed, the concentration of unadsorbed europium ions in the original solution was measured by ICP, and the adsorption capacity was calculated based on the result.

[0074] The results show that the highest saturated adsorption capacity of IIMs is 41.06 mg/g, which is significantly higher than the 18.22 mg/g of NIMs.

[0075] (5) Selective adsorption experiment

[0076] Weigh 5 parts of Eu-IIMs, put them into 5 glass test tubes, and add 10 mL of 5, 10, 25, 50, 100 mg/L mixed aqueous solution containing the same concentration of europium, lanthanum, and gadolinium ions. Shake in a constant temperature water bath at 35°C for 3 hours. After the adsorption is completed, the concentration of unadsorbed europium ions in the original solution is determined by ICP, and the adsorption capacity is calculated based on the results.

[0077] The results showed that the highest saturated adsorption capacity of Eu-IIMs for europium ions in competitive adsorption was 41.06 mg/g, and the highest saturated adsorption capacities for lanthanum and gadolinium ions were 14.32 mg/g and 18.33 mg/g, respectively. The selection factors were respectively Are 2.87 and 2.24.

[0078] (6) Selective permeability experiment

[0079] Self-made combined H-shaped glass permeation device, the middle is disconnected into two grinding mouth branch pipes, Eu-IIMs or Eu-NIMs are fixed between the grinding mouths of the two glass tanks, and the connection is sealed with degreasing tape and waterproof tape to ensure that the device is free To leak, add a mixed aqueous solution of europium chloride, lanthanum nitrate and gadolinium nitrate with the same ion concentration in one sample cell, add an equal volume of deionized water to the other sample cell, put a magnet in each of the two sample cells, The device is placed in a constant temperature water bath and stirred at 35°C. The ion concentration through the imprinted composite membrane is measured by ICP, and the permeation amount is calculated based on this.

[0080] Eu-IIMs selective permeation experiment results show that the sampling time is 5, 10, 15, 30, 45, 60, 90, 120 in a mixed aqueous solution with the initial concentration of europium ion, lanthanum ion and gadolinium ion of 100 mg/L. At 180 minutes, the europium ion concentrations in the blank sample cell were 0.011, 0.053, 0.075, 0.117, 0.149, 0.178, 0.191, 0.238, 0.265 mg/L, and the lanthanum ion concentrations were 0.029, 0.223, 0.348, 0.507, 0.668, 0.774, 0.855, 0.926, 0.997 mg/L, the measured gadolinium ion concentrations were 0.038, 0.210, 0.338, 0.455, 0.583, 0.681, 0.751, 0.838, 0.907 mg/L.

[0081] Eu-NIMs selective permeation experiment results show that the sampling time is 5, 10, 15, 30, 45, 60, 90, 120 in a mixed aqueous solution with the initial concentration of europium ion, lanthanum ion, and gadolinium ion at 100 mg/L. At 180 minutes, the europium ion concentration in the blank sample cell was 0.088, 0.270, 0.378, 0.563, 0.696, 0.771, 0.858, 0.908, 0.997 mg/L, and the measured lanthanum ion concentration was 0.059, 0.273, 0.388, 0.565, 0.714, 0.804, 0.915, 0.958, 1.048 mg/L, and the measured gadolinium ion concentrations were 0.034, 0.260, 0.368, 0.555, 0.675, 0.751, 0.831, 0.891, 0.967 mg/L, respectively.

[0082] by figure 2 It can be seen that, compared with the unmodified silica nanospheres, the surface of the silica nanospheres modified by KH-570 has a translucent coating layer, which combines image 3 The phenomenon that the imprinted polymer is distributed around the nanospheres in the scanning image indicates that the surface of the silica nanospheres has been successfully modified. by image 3 In the SEM image, it can be seen that, compared with the membrane materials obtained in other steps, a uniformly dispersed and irregularly shaped imprinted polymer layer appears on the surface of the finally obtained Eu-IIMs, which proves the successful synthesis of europium ion imprinted polymer layer on the membrane surface , Combined with the excellent selective adsorption data of Eu-IIMs at 35℃, the results show that Eu-IIMs have specific adsorption of template ions (europium ions) and promote the permeation of non-template ions (lanthanum ions and gadolinium ions).

[0083] Example 3

[0084] (1) Surface modification of regenerated cellulose membrane

[0085] First, put 0.1211g Tris and 0.2g DA in 100mL deionized water, mix thoroughly under ultrasonic conditions, adjust the pH to 8.5 to obtain a mixed solution, immerse 3 pieces of RCMs in the mixed solution, and react for 6 hours under room temperature shaking to obtain the modified For supporting membrane dRCMs, take out the modified supporting membrane, soak and wash it with deionized water three times for 10 minutes each time, and dry the cleaned modified supporting membrane at room temperature.

[0086] (2) Preparation of non-self-supporting graphene oxide composite film

[0087] First, add 0.5g of silica nanospheres with a diameter of ~300nm to a mixed solution of 100mL of ethanol and water (ethanol:water=4:1), add 3mL of KH-570 after 5 minutes of nitrogen flow, and seal with degreasing tape. React at 80°C for 16 hours. After centrifugation, the product (kSiO2) is washed with alcohol and water for three times. The kSiO2 is washed under vacuum at 40°C. 2 Drying; weigh out 5mg of dried kSiO 2 Placed in 50mL deionized water and mixed thoroughly with ultrasound to obtain kSiO with a concentration of 100mg/L 2 Solution, put 5mg GO in 50mL deionized water, mix thoroughly with ultrasound to obtain a GO solution with a concentration of 100mg/L, respectively measure 5mL kSiO 2 The solution and 5mL GO solution were mixed and mixed uniformly under ultrasonic conditions. The solids in the mixed solution were suction filtered onto dRCMs under a vacuum pressure of 0.07MPa to obtain non-self-supporting graphene oxide composite membrane CMs. The CMs were dried at room temperature dry.

[0088] (3) Preparation of temperature-responsive europium ion-imprinted composite membrane

[0089] First, 8mL of a tetrahydrofuran solution with a concentration of 1mol/L phenylmagnesium bromide was heated to 40℃ under the protection of nitrogen, and 0.6mL CS was slowly added dropwise with a syringe. 2 , Keep the temperature at 40℃ for 1 hour under the protection of nitrogen, add 1.1mLC dropwise with a syringe 7 H 7 Br, heated to 50°C for 2 hours under the protection of nitrogen, and the product was naturally cooled to room temperature, then 30mL deionized water was added, extracted with 30mL petroleum ether with a boiling range of bp90~120°C, and the organic phase was retained to obtain a chain transfer reagent CTA; add 0.075g EuCl 3 • 6H 2 O, 0.3mmol Am, 0.3mmol NIPAm, and 6mmol EGDMA were added to 60mL of acetonitrile, and the solution was mixed uniformly under ultrasonic conditions. Three pieces of CMs were added to the above mixed solution. Nitrogen was added to the solution for 10 minutes. Under nitrogen, add 30μL of the prepared CTA and 50mg AIBN to the solution, continue nitrogen flow for 10 minutes, then seal with vacuum glass stopper, degreasing tape and cling film, heat up the reactant to 50℃ and maintain it for 6 hours to make the reactant proceed. After pre-polymerization, the reactants were heated to 60°C, and the reactants were subjected to imprinting polymerization for 36 hours. The product film was taken out and soaked in ethanol for three times for 10 minutes each, and then washed and soaked in deionized water three times, After 10 minutes, dry at room temperature to obtain the imprinted composite membrane; place 3 pieces of the obtained imprinted composite membrane in 200mL of 1mol/L hydrochloric acid solution to elute template ions, and replace the hydrochloric acid solution every 6 hours, the elution process For three days, the eluted membrane was taken out and dried at room temperature to obtain a temperature-responsive europium ion imprinted composite membrane Eu-IIMs-3.

[0090] (4) Static adsorption experiment

[0091] Weigh 5 parts of Eu-IIMs and Eu-NIMs respectively, put them into 10 glass test tubes, and add 10 mL of EuCl with concentrations of 5, 10, 25, 50, 100 mg/L. 3 The aqueous solution is shaken in a constant temperature water bath at 45°C for 3 hours. After the adsorption is completed, the concentration of unadsorbed europium ions in the original solution is measured by ICP, and the adsorption capacity is calculated based on the result.

[0092] The results show that the highest saturated adsorption capacity of IIMs is 41.06 mg/g, which is significantly higher than the 18.22 mg/g of NIMs.

[0093] (5) Selective adsorption experiment

[0094] Weigh 5 parts of Eu-IIMs, put them into 5 glass test tubes, and add 10 mL of 5, 10, 25, 50, 100 mg/L mixed aqueous solution containing the same concentration of europium ions, lanthanum ions, and gadolinium ions. Shake in a constant temperature water bath at 45°C for 3 hours. After the adsorption is completed, the concentration of unadsorbed europium ions in the original solution is determined by ICP, and the adsorption capacity is calculated based on the results.

[0095] The results showed that the highest saturated adsorption capacity of Eu-IIMs for europium ions in competitive adsorption was 41.06 mg/g, and the highest saturated adsorption capacities for lanthanum and gadolinium ions were 14.32 mg/g and 18.33 mg/g, respectively. The selection factors were respectively Are 2.87 and 2.24.

[0096] (6) Selective permeability experiment

[0097] Self-made combined H-shaped glass permeation device, the middle is disconnected into two grinding mouth branch pipes, Eu-IIMs or Eu-NIMs are fixed between the grinding mouths of the two glass tanks, and the connection is sealed with degreasing tape and waterproof tape to ensure that the device is free from leakage To leak, add a mixed aqueous solution of europium chloride, lanthanum nitrate and gadolinium nitrate with the same ion concentration in one sample cell, add an equal volume of deionized water to the other sample cell, put a magnet in each of the two sample cells, The device is placed in a constant temperature water bath and stirred at 45°C. The ion concentration through the imprinted composite membrane is measured by ICP, and the permeation amount is calculated based on this.

[0098] Eu-IIMs selective permeation experiment results show that the sampling times are 5, 10, 15, 30, 45, 60, 90, 120 in a mixed aqueous solution with the initial concentrations of europium, lanthanum, and gadolinium ions all being 100 mg/L. At 180 minutes, the europium ion concentration in the blank sample cell was 0.025, 0.258, 0.348, 0.524, 0.655, 0.686, 0.823, 0.934, 1.268 mg/L, and the lanthanum ion concentration was 0.027, 0.225, 0.351, 0.521, 0.644, 0.769, 0.847, 0.930, 1.053 mg/L, and the measured concentrations of gadolinium ions were 0.034, 0.217, 0.346, 0.479, 0.613, 0.685, 0.764, 0.890, 0.984 mg/L, respectively.

[0099] Eu-NIMs selective permeation experiment results show that the sampling time is 5, 10, 15, 30, 45, 60, 90, 120 in a mixed aqueous solution with the initial concentration of europium ion, lanthanum ion, and gadolinium ion at 100 mg/L. At 180 minutes, the europium ion concentration in the blank sample cell was 0.065, 0.264, 0.384, 0.558, 0.671, 0.785, 0.854, 0.912, 1.215 mg/L, and the lanthanum ion concentration was 0.062, 0.273, 0.391, 0.534, 0.684, 0.821, 0.876, 0.905, 1.169 mg/L, and the measured gadolinium ion concentrations were 0.057, 0.250, 0.397, 0.537, 0.673, 0.776, 0.861, 0.931, 1.193 mg/L, respectively.

[0100] The transmission diagram of the material in Example 3 is similar to that in Example 2, which is determined by figure 2 It can be seen that, compared with the unmodified silica nanospheres, the surface of the silica nanospheres modified by KH-570 has a translucent coating layer, which combines image 3 The phenomenon that the imprinted polymer is distributed around the nanospheres in the scanning image indicates that the surface of the silica nanospheres has been successfully modified. The scanning electron micrograph of the film material in Example 3 is similar to that in Example 2, which is determined by image 3 It can be seen that, compared with the membrane materials obtained in other steps, a uniformly dispersed and irregularly shaped imprinted polymer layer appeared on the surface of the finally obtained Eu-IIMs, which proved that the europium ion imprinted polymer layer was successfully synthesized on the membrane surface.

[0101] Combining the experimental data and characterization results of Example 1, Example 2 and Example 3, the results show that the prepared Eu-IIMs has high specific adsorption to template ions (europium ions) and promotes non-template ions at 35°C (Lanthanum ion and Gadolinium ion) permeation performance, that is, the Eu-IIMs prepared have the ability to recognize and separate europium ions with temperature response.