Article ID Journal Published Year Pages File Type
9562593 Reactive and Functional Polymers 2005 14 Pages PDF
Abstract
Poly(oxypropylene) bisphosphates (POPBPs) have been synthesized by modification of polypropylene glycols (PPG400, 1200, 2000) and used as macroionophores of metal cations in a multimembrane hybrid system comprising a flowing liquid membrane unit, cation exchange, and pervaporation polymer membranes. POPBPs ability to mediate the selective pertraction of some cations from a multication mixture containing alkali (K+, Na+), alkaline earth (Ca2+, Mg2+) and transient metal cations (Zn2+, Cu2+) has been studied and compared with the properties of respective PPGs. POPBPs, after dissolving in 1,2-dichloroethane (liquid membrane phase), have been observed to transport and separate cations in the following order: Zn2+ > Cu2+ ≫ Ca2+, Mg2+, K+, Na+. An increase in the molecular mass of POP chain changes the position of K+ cations in the order from Zn2+ > Cu2+ > K+ ⩾ Na+, Ca2+ > Mg2+ to Zn+, K+ > Na+ >  Ca2+ > Cu2+, Mg2+ as observed for PPG400 and PPG2000, respectively. High ionic fluxes and separation properties of POPBs are dependent mainly on the presence of ionisable phosphoric acid end-groups. These groups, in cooperation with poly(oxypropylene) chains, mediate the proton-coupled transport of cations (counter-transport) resulting in the effective up-hill transport of Zn2+ cations.
Related Topics
Physical Sciences and Engineering Chemistry Organic Chemistry
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