Reactive & Functional Polymers, Vol.52, No.3, 149-161, 2002
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
A functionalized star-shaped polymer [CH3O(CH2CH2O)(n)](x) -[DGEEG]-[(CH2CH2O)(m)P(O)(ONa)(2)](x,) (MPOE-[DGEEG]-POEP), with the overall molecular mass approx. 2 X 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 Zn2+ and K+ cations from a multication feed solution containing alkali (K+, Na+), alkaline earth (Mg2+, Ca2+) and transition metal cations (Cu2+, Zn2+). 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: Zn2+ >K+> Na+> CU2+, Mg2+, Ca2+; PEG4000: K+ >> Na+ > Zn2+, CU2+, Ca2+, Mg2+; PEG6000: K+ << Zn2+ Ca2+, Na+, CU2+, Mg2+. (C) 2002 Elsevier Science B.V. All rights reserved.