Study of poly(acrylamidoxime) brushes conformation with uranium adsorption by neutron reflectivity

Chain conformation of surface tethered poly(acrylamidoxime) brushes plays an important role in increasing their uranium adsorption capacity in seawater. In this work, poly(acrylamidoxime) brushes are prepared via surface-initiated activators regenerated by electron transfer atom-transfer radical polymerization. For the first time, in situ neutron reflectivity experiments are employed to investigate the conformation of poly(acrylamidoxime) brushes in deuterated water containing UO22+ ions. It is found that the poly(acrylamidoxime) brushes shrink when UO22+ ions are adsorbed due to the multiple coordination effect. However, this phenomenon is unfavorable for further adsorption of UO22+ ions in poly(acrylamidoxime) brushes because UO22+ ions solutions are subsequently discharged from the polymer brushes.