Iron(III) extraction from chloride media by N,N'-tetrasubstituted malonamides: an interfacial study

M Soledade C S Santos; Ana Paula Paiva

doi:10.1016/j.jcis.2013.09.017

Iron(III) extraction from chloride media by N,N'-tetrasubstituted malonamides: an interfacial study

J Colloid Interface Sci. 2014 Jan 1:413:78-85. doi: 10.1016/j.jcis.2013.09.017. Epub 2013 Sep 25.

Authors

M Soledade C S Santos¹, Ana Paula Paiva

Affiliation

¹ Centro de Química e Bioquímica (CQB), Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa (DQB-FCUL), Rua Ernesto de Vasconcelos, Edifício C8, 1749-016 Lisboa, Portugal. Electronic address: mssantos@fc.ul.pt.

PMID: 24183433
DOI: 10.1016/j.jcis.2013.09.017

Abstract

The interfacial behaviour of two N,N'-tetrasubstituted malonamides, N,N'-dimethyl-N,N'-diphenyl malonamide (DMDPHMA) and N,N'-dimethyl-N,N'-dicyclohexylmalonamide (DMDCHMA), in the liquid-liquid (L/L) extraction of iron(III) from hydrochloric acid solutions, was studied. The experimental results obtained validate the absence of third phases for these systems. The equilibrium adsorption constants and surface excess concentrations, estimated by the Szyszkowski model, explain the experimental extraction efficiency patterns for both malonamides in the two diluents tested, 1,2-dichloroethane (1,2-DCE) and toluene. A solvation type mechanism is in accordance with all the results obtained, accounting for the structural and diluent effects observed.

Keywords: Interfacial tension; Iron(III) extraction from chloride media; N,N′-tetrasubstituted malonamides; Structural and diluent effects.