Kinetic effects of the complexation reaction in the facilitated ion transfer at liquid membrane systems of one and two polarized interfaces. Theoretical insights.
An in-depth study of the ion transfer facilitated by complexation in the organic phase (TOC mechanism) in liquid membrane systems of one and two polarized interfaces is carried out by taking into account the kinetic effects associated with the complexation reaction. Explicit analytical equations for the normal pulse voltammetric (I/E) and chronoamperometric (I/t) responses with an explicit dependence on the kinetic parameters of the chemical complexation are presented for both kinds of membrane system, which could be useful for modeling artificial and biological membranes. The equations are compared with those obtained by using the widely used approximation of total equilibrium conditions that leads to the transfer by interfacial complexation mechanism (TIC), which only depends on thermodynamic parameters. Simple methods are proposed that allow quantitative determination of the equilibrium and kinetic constants of the complexation reaction in the organic phase for both kinds of membrane system.
Departamento de Química Física, Facultad de Química, Universidad de Murcia, 30100 Murcia, Spain. amolina@um.es
Ángela
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Molina
Encarnación
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Torralba
Carmen
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Joaquín A
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Ortuño
D007477:Ions / Q000737:chemistry; D007700:Kinetics; D008567:Membranes, Artificial; D013816:Thermodynamics
D007477:Ions; D008567:Membranes, Artificial