The adsorption of cations by ionic phosphorylated polymers

Abstract

A preliminary investigation of the adsorption properties of ionic diallyl phosphate polymers has been conducted. Sodium diallyl phosphate polymer (NaDAP), separates hexavalent uranium (UO22+) quantitatively from alkaline earths (Ca and Sr), ferric and divalent elements of the first transitional period, aluminium and lanthanides dissolved together in a 2% w/v solution of disodium ethylene‐diaminetetra‐acetate. Unlike in quantitative separations of uranium from other cations by anion exchangers, the presence of sulphuric acid and the reduction of ferric to ferrous ion is not essential with NaDAP, and nitrate, chloride or perchlorate anions do not interfere. Elution of the adsorbed uranium is conducted with a solution of sodium carbonate. Separation from thorium and fission product β‐activity (after 96 hours' decay) under similar conditions was 91% and 92% respectively. The adsorption sequence for the resin is Th4+ > Fe3+ > UO22+ > La3+ > Cu2+ > Ca2+ > Na. From analogy with complexes formed with dibutyl phosphate and the high affinity of the resin for polyvalent cations it appears that these are adsorbed through the formation of stable foru‐membered ring complexes with the resin functional groups. An equivalent of acid is liberated for each equivalent of uranyl and ferric ion adsorbed by acid diallyl phosphate polymer (HDAP).

Phosphonate‐Containing Polymeric Networks: Swelling in Water Controlled by Metal Ions

“…However, the La 3+ cation is much larger than the Fe 3+ cation, the resulting distance between the phosphonates was increased and allows some diffusion of water into the gel. In conclusion, the water absorption of the discs reflects the classification of the cations Fe 3+ > La 3+ > Ca 2+ . In the pictures shown in Figure , it can be seen that the edges of the discs are ragged and wavy.…”

“…In conclusion, the water absorption of the discs refl ects the classifi cation of the cations Fe 3+ > La 3+ > Ca 2+ . [ 28 ] In the pictures shown in Figure 2 , it can be seen that the edges of the discs are ragged and wavy. Probably, the uncontrolled swelling can Macromol.…”

Cation-Exchange Techniques in Radiochemistry

“…A separation of UO from Fe , Cu , 2+ 2+ Co and La was described. The four latter ions were eluted with EDTA 2+ and UO with carbonate (293). A separation from fission products was 2+ also described.…”