High surface area, ordered nanoporous carbon (CMK-3) and its chelating polymer composites were successfully prepared and utilized
for the removal of U(VI) from aqueous solutions. Carboxymethylated polyethyleneimine (CMPEI) with a strong chelating property
was introduced to the pore surface and inner pores of CMK-3 substrate. CMPEI-modified CMK-3 composite (CMPEI/CMK-3) was characterized
by scanning electron microscopy and nitrogen sorption. U(VI) sorption capacity was significantly improved by the surface modification
of CMK-3 by CMPEI. The CMPEI/CMK-3 showed enormously increased sorption capacities, compared with those of previous sorbents
(e.g., surface-functionalized silicas). In particular, the CMPEI/CMK-3 showed a significantly high uranium retention property
while allowing only about 1% U(VI) to leach out over a 4 month time period, when treated with polyacrylic acid.