Removal of Actinides from Acidic Solution via Carrier-Mediated Facilitated Transport Across Mesoporous Substrates with Nanoengineered Surfaces: Thiol Self-Assembled Monolayers with D(tBu)ΦD(iBu)CMPO Ligands

Abstract:

The surface engineering of polycarbonate track-etched (PCTE) membranes was performed to create a permselective membrane for the removal of trace levels of fission products and transuranic metals from acidic streams. Electroless gold deposition was used to place a gold coating on the PCTE substrates. The gold coating was subsequently functionalized through the formation of a self-assembled monolayer of dodecanethiol, which was further functionalized with di-(4-t-butylphenyl)-N, N-diisobutylcarbamoylmethylphosphine oxide. Transport characteristics of metal ions, ¹³⁷Cs, ⁸⁵Sr, ²⁴¹Am, and ²³⁹Pu, were obtained using a two-compartment diffusion apparatus. Transport studies showed that the functionalized membranes enhance the transport rates of ²⁴¹ Am and ²³⁹Pu and inhibit the transport of ¹³⁷Cs and ⁸⁵Sr. Diffusion studies over an extended time revealed that the facilitated transport characteristics of ²³⁹Pu through the ligand-coated membranes are dependent on nitrate anion concentrations in the feed and sink cells.