Kinetic Study of Hg(II) Transport Through a Bulk Liquid Membrane Containing Ester Derivative of bis‐Calix[4]arene

Abstract

A kinetic study of Hg(II) transport from an aqueous donor solution into an aqueous acceptor solution through a bulk liquid membrane containing N,N′‐bis[carbonylmethoxy(5,11,17,23‐tetra‐tert‐butyl‐25,26,27‐tris‐(ethoxycarbonyl‐methoxy)calix(4)arenyl)]‐1,2‐diaminoethane as a carrier was studied. The kinetic parameters (k 1d, k 2m, k 2a, t max, R m max, J d max, J a max) for the transport were investigated in terms of the effect of temperature, the stirring rate, the carrier concentration, and the type of solvent. In this study, the pseudo‐first‐order apparent rate constant of the interfacial transport of the Hg(II) is determined by using the spectrophotometric method. The kinetics of the transport was analyzed in the formalism of two consecutive irreversible first‐order reactions. The membrane entrance and exit rate constants were increased with increasing of temperature, stirring rate, and carrier concentration. The membrane entrance and exit rate constants depended on the type of solvent and was found to be in the order of CH2Cl2 > CHCl3 > CCl4. The activation energy values are calculated as 25.50 ± 2.20 and 45.62 ± 4.38 kJ mol−1 for extraction and reextraction, respectively. The values of the calculated activation energy indicate that the process is diffusionally controlled by species.