Determination of the critical micellar concentration of perfluorinated surfactants by cyclic voltammetry at liquid/liquid interfaces.

BENJAMÍN VIADA; ANA VALERIA JUÁREZ; ERICA MARCELA PACHÓN GÓMEZ; MARIANA A. FERNÁNDEZ; LIDIA MABEL YUDI

ELECTROCHIMICA ACTA

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2018 vol. 263 p. 499 - 499

0013-4686

ypothesis Cyclic voltammetry applied to the interface formed by two immiscible electrolyte solutions can be used for determining critical micellar concentrations (cmc) of charged surfactants provided they exhibit ion transfer currents. ExperimentsThree perfluorinated acids (perfluoroctanoic acid, PFO, perfluorononanoic acid, PFN, and perfluorodecanoic acid, PFD), dissolved in the aqueous phase, was studied by cyclic voltammetry at the water/1,2-dichloroethane interface. Other methodologies, as fluorescence and surface pressure measurements, were also used for comparison.FindingsFrom the variation of voltammetric parameters on surfactant concentration it was possible to determine the cmc for these surfactants, obtaining good agreements with other methodologies. Impedance spectroscopy experiments have been also carried out to characterize the properties of the interface, demonstrating that at high surfactant concentration values, a monolayer with different domains is formed.