Synthesis of Amidoxime‐modified Hollow Organic Porous Nanospheres for Efficient Uranium Adsorption from Aqueous Solution

Abstract

Despite its disadvantages, nuclear power still has some advantages over traditional fossil fuels and could have a part to play in solving the current energy crisis. Among them, nuclear waste (mainly uranium and plutonium) is the inevitable product of the extensive development and application of nuclear power, and its recovery and storage technology are on the focus of scientific research. Herein, amidoxime‐modified hollow organic porous nanospheres (HOPNs‐AO) were prepared by co‐hyper‐crosslinking from polylactide‐b‐polystyrene (PLA‐b‐PS) diblock copolymer and benzeneacetonitrile based on the Scholl coupling reaction. Owing to the specific adsorption property of amidoxime groups for uranyl ions, the obtained HOPNs‐AO exhibited excellent adsorption capacity (qmax=519.5 mg ⋅ g−1), chemical stability, and selectivity for uranyl ions in an aqueous solution. In addition, HOPNs‐AO can still maintain more than 80 % adsorption capacity in the fifth cycle. The above results indicate that the successful design of this material provides a meaningful way for the recovery of uranium ions in aqueous solution.

4-(5-Benzyl-3-((4-fluorophenyl)sulfonyl)-5-methyl-4,5-dihydrofuran-2-yl)-2-nitrobenzamide

“…Residual 1 H and 13 C peaks in deuterated solvent (CDCl 3 ) were used for chemical shift calibration without the need for an additional internal standard. 1 H NMR: reference CDCl 3 δ = 7.26 ppm and 13 C NMR: reference CDCl 3 δ = 77.16 ppm. Data for 1 H NMR are reported as follows: chemical shifts (δ) in parts per million (ppm), multiplicity (described as follows: s, singlet; bs, broad singlet; d, doublet; t, triplet; q, quadruplet; dd, doublet of doublet; ddd, doublet of doublet of doublet; m, multiplet), coupling constants (J) in Hertz (Hz) and integration.…”

“…The product was obtained as a light orange solid. 1 H NMR (400 MHz, CDCl 3 ): δ (ppm) 8.32 (s, 1H, CH Ar ), 7.86 (d, 3 J H-H = 8.0 Hz, 1H, CH Ar ), 7.78 (d, 3 J H-H = 8.0 Hz, 1H, CH Ar ), 6.80 (dd, 3 J H-H = 10.9 Hz, 3 J H-H = 17.6 Hz, 1H, CH), 6.05 (d, 3 J H-H = 17.6 Hz, 1H, H-CH 2 ), 5.66 (d, 3 J H-H = 10.9 Hz, 1H, H-CH 2 ). 13…”

“…The reaction vessel was allowed to stir at 80 • C for 72 h. The TLC monitoring reaction was performed using cyclohexane-AcOEt (1:1) as an eluent and visualized with ultraviolet light under a UV-Lamp VL-6.CL., 254 nm (6 W), with a retardation factor of 0.45, and verified via low-resolution LC-MS. After the reaction, the resulting mixture was concentrated under vacuum and the residue was purified by flash column chromatography using a mixture of petroleum ether-AcOEt (from 9:1 to 4:6) as an eluent to give the desired product as a light brown solid with a yield of 39% (196 mg). 1 H NMR (400 MHz, CDCl 3 ): δ (ppm) 8.88 (s, 1H, CH Ar ), 8.45 (d, 3 J H-H = 8.1 Hz, 1H, CH Ar ), 8.12 (d, 3 J H-H = 8.1 Hz, 1H, CH Ar ), 7.92-7.89 (m, 2H, CH Ar ), 7.34-7.29 (m, 2H, CH Ar ), 4.79 (s, 2H, CH 2 ). 13 C NMR (100 MHz, CDCl 19 In a microwave vial of 20 mL equipped with a stirring bar, a solution of manganese (III) acetate dihydrate (2.1 equiv.)…”

“…Yield: 37% (84 mg). 1 H NMR (400 MHz, CDCl 3 ): δ (ppm) 8.45 (d, 4 J H-H = 1.6 Hz, 1H, CH Ar ), 8.06 (dd, 4 J H-H = 1.6 Hz, 3 J H-H = 8.1 Hz, 1H, CH Ar ), 7.94 (d, 3 J H-H = 8.2 Hz, 1H, CH Ar ), 7.58-7.54 (m, 2H, 2CH Ar ), 7.24-7.12 (m, 5H, 5CH Ar ), 7.05 (d, 3 J H-H = 8.2 Hz, 2H, 2CH Ar ), 3.04 (d, 2 J H-H = 14.7 Hz, 2H, CH 2 ), 2.92-2.82 (m, 2H, CH 2 ), 1.43 (s, 3H, CH 3 ). 13 In a microwave vial of 20 mL equipped with a stirring bar, a solution of compound 3 (45 mg, 0.09 mmol), in water (2 mL) and ethanol (9 mL) was inserted.…”

“…Amidoxime is a functional group extensively studied for environmental applications, for example in the treatment of seawater or wastewater [1][2][3]. The growing number of citations and publications over time indicates significant interest, which extends to other fields such as polymer science, organic chemistry and medicinal chemistry [4][5][6][7][8].…”