pH Effect on the uranium adsorption from seawater by a macroporous fibrous polymeric material containing amidoxime chelating functional group

Recovery of uranyl from aqueous solutions using amidoximated polyacrylonitrile/exfoliated Na-montmorillonite composite

“…Similar phenomenon was observed using different adsorbents [30]. Electrostatic interaction, H + concentration and the uranyl species may be responsible for this.…”

Poly(amidoxime)-reduced graphene oxide composites as adsorbents for the enrichment of uranium from seawater

“…Once initiated by (NH 4 ) 2 S 2 O 8 , acrylonitrile monomers began to polymerize and form many tiny and irregular protuberances on GO surfaces, which give a good dispersion status of PAO on GO surfaces. The polymerized poly(acrylonitrile) could function as new "active centers" for a further polymerization process to form porous microstructures, which provided convenient diffusion channels for metal ions (such as UO 2 2+ ) into the interior of adsorbent [27][28][29] and also improved its adsorption capacity. However, too much poly(acrylonitrile) in the formed pore and hole can reduce the pore size and/or even fill the pores of adsorbents (such as 4.0PAO/rGO), which would have an adverse effect on the interior diffusion of UO 2 2+ in PAO/rGO composites and would reduce its adsorption capability.…”

“…This result suggests that the adsorption of UO 2 2+ on PAO/rGO composites is affected by the hydrolysis of UO 2 2+ ions and the protonation-deprotonation of PAO in aqueous solutions. Barber et al [18] and Zhang et al [28,29] reported that PAO is normally protonated in acidic solution, and that the protonation-deprotonation of PAO and the hydrolysis of UO 2 2+ ions in aqueous solution are important factors that affect the adsorption of UO 2 2+ on PAO-containing materials.…”

Preparation and chelation adsorption property of composite chelating material poly(amidoxime)/SiO2 towards heavy metal ions

“…Among these chelation groups, amidoxime group has very strong chelation action towards many rare earth and heavy metal ions, so the chelating materials carrying amidoxime groups attract much attention in the enrichment, recovery and removal of rare earth and heavy metal ions [17][18][19]. Especially, in uranium recovery from seawater, the amidoxime-type chelating materials play a unique role [20][21][22][23]. Most of amidoxime-type chelating adsorption materials are derived from the chemical transform of polyacrylonitrile [24][25][26].…”