Successful Coupling of a Bis-Amidoxime Uranophile with a Hydrophilic Backbone for Selective Uranium Sequestration.
The amidoxime group (-RNH2NOH) has long been used to extract uranium from seawater on account of its high affinity toward uranium. The development of tunable sorbent materials for uranium sequestration remains a research priority as well as a significant challenge. Herein, we report the design, synthesis, and uranium sorption properties of bis-amidoxime-functionalized polymeric materials (BAP 1-3). Bifunctional amidoxime monomers were copolymerized with an acrylamide cross-linker to obtain bis-amidoxime incorporation as high as 2 mmol g-1 after five synthetic steps. The resulting sorbents were able to uptake nearly 600 mg of uranium per gram of polymer after 37 days of contact with a seawater simulant containing 8 ppm uranium. Moreover, the polymeric materials exhibited low vanadium uptake with a maximum capacity of 128 mg of vanadium per gram of polymer. This computationally predicted and experimentally realized selectivity of uranium over vanadium, nearly 5 to 1 w/w, is one of the highest reported to date and represents an advancement in the rational design of sorbent materials with high uptake capacity and selectivity.
['Piechowicz|Marek|M|', 'Abney|Carter W|CW|http://orcid.org/0000-0002-1809-9577', 'Thacker|Nathan C|NC|', 'Gilhula|James C|JC|', 'Wang|Youfu|Y|', 'Veroneau|Samuel S|SS|', 'Hu|Aiguo|A|http://orcid.org/0000-0003-0456-7269', 'Lin|Wenbin|W|http://orcid.org/0000-0001-7035-7759']
amidoxime seawater DFT cooperative binding uranium extraction