US EPA

5452253 

Journal Article 

Potassium ion transport processes across the interface of an immiscible liquid pair in the presence of crown ethers 

Sinru, L; Zaofan, Z; Freiser, H 

1986 

1 

Journal of Electroanalytical Chemistry and Interfacial Electrochemistry
ISSN: 0022-0728 

210 

1 

137-146 

http://www.sciencedirect.com/science/article/pii/0022072886903190
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The mechanism of potassium ion transfer from an aqueous to a 1,2-dichloroethane phase which is facilitated by urushiol crown ether or dibenzo-18-crown-6 in the range of potassium concentrations, cK+, from 0.1 mM to 1 M was studied by current scan polarography at the ascending water electrode, chronopotentiometry, and chronopotentiometry with current reversal at the stationary water electrode. At cK+ below 0.02 M a single polarographic wave is obtained, which corresponds to the transfer of K+-crown ether complex from the aqueous phase. At cK + ≥ 0.02 M, an additional wave appears at a less positive potential which grows at the expense of the first wave, which finally disappears at higher cK+. The second wave results from the transfer of a simple potassium ion across the interface, where it reacts with the crown ether. At cK+ at which the additional wave begins to appear, the formation reaction of K+-crown ether takes place at the aqueous side of the interface.