PALLADIUM(II) EXTRACTION AND EXTRACTANT ADSORPTION AT A LIQUID LIQUIDINTERFACE/

Interfacial tension isotherms were determined for individual palladium (II) extractants and interpreted. The following extractants were consi dered: 4-alkylphenylamines containing from 6 to 14 carbon atoms in the alkyl group, dihexylsulfide, 2-hydroxyethyldecyl sulfide and its part ly fluorinated derivative, decylnicotiniate and N,N-dihexylpyridine-3- carboxamide. 4-Alkylphenylamines exhibited significantly stronger inte rfacial activity than did the other extractants. They adsorbed at the hydrocarbon/water interfaces already at concentrations 10(-5) M and pe rmit to decrease the interfacial tension to 5 mN m(-1). As a result, t hey can be used as a phase transfer catalyst to increase the rate of p alladium(II) extraction with other extractants. When used alone, the i nitial rate of extraction increases with the extractant increasing hyd rophobicity, thus in the order of increased interfacial activity.