Synthesis and characterization of a novel core-shell magnetic nanocomposite via surface-initiated RAFT polymerization for highly efficient and selective adsorption of uranium(VI)

In this work, the nanoparticles possessing a macro-initiator (MNPs@SCSOEt) were firstly obtained by surface-initiated RAFT polymerization. The structure of the nanocomposite was characterized by FT-IR, SEM, TEM, TGA, XPS and VSM. The effects of pH, contact time, initial uranium concentrations, coexisting ions and temperature on the U(VI) adsorption by MNPs@PAO were investigated in detail. The adsorption process was found to be in good agreement with pseudo-second order kinetic model and Langmuir adsorption isotherm model. The maximum adsorption capacity was estimated to be 216.45 mg/g by fitting Langmuir model with the equilibrium data. The adsorption process was endothermic and spontaneous. In addition, the adsorption capacity of MNPs@PAO for U(VI) decreased slightly after five successive adsorption/desorption cycles. (author)