Properties of star-shaped polymer with poly(oxyethylene) branches and monoesters of phosphoric acid end groups in pertraction of alkali, alkaline earth, and transient metal cations

Abstract

A functionalized star-shaped polymer [CH 3O(CH 2CH 2O) n ] x –[DGEEG]–[(CH 2CH 2O) m P(O)(ONa) 2] x , (MPOE–[DGEEG]–POEP), with the overall molecular mass approx. 2×10 5 and more than 40 side-arms, was used as the macroionophore of metal cations in a complex membrane system MHS[FLM-PV]. The system comprised a hybrid membrane system (MHS) with a liquid membrane (FLM) flowing between two cation-exchange membranes. Additionally, the FLM was continuously dehydrated by applying the pervaporation method (PV). The macroionophore, after dissolving in 1,2-dichloroethane, has been observed to mediate selective pertraction (liquid membrane transport) of Zn 2+ and K + cations from a multication feed solution containing alkali (K +, Na +), alkaline earth (Mg 2+, Ca 2+) and transition metal cations (Cu 2+, Zn 2+). In parallel experiments it was found that poly(ethylene glycol)s (PEG4000 and 6000) transports selectively only K + cations. The following selectivity sequences have been established from the values of separation coefficients and ionic fluxes. MPOE-DGEEG-POEP: Zn 2+>K +>Na +>Cu 2+, Mg 2+, Ca 2+; PEG4000: K +≫Na +>Zn 2+, Cu 2+, Ca 2+, Mg 2+; PEG6000: K +≫Zn 2+, Ca 2+, Na +, Cu 2+, Mg 2+.