Condensed film formation of binary mixtures of cetyltrimethylammonium bromide and cetyldimethylbenzylammonium chloride in a wide potential region at the mercury/electrolyte interface

Argiro Koniari; Antonis Avranas

doi:10.1016/j.jcis.2006.08.043

Condensed film formation of binary mixtures of cetyltrimethylammonium bromide and cetyldimethylbenzylammonium chloride in a wide potential region at the mercury/electrolyte interface

J Colloid Interface Sci. 2006 Dec 1;304(1):172-9. doi: 10.1016/j.jcis.2006.08.043. Epub 2006 Sep 20.

Authors

Argiro Koniari¹, Antonis Avranas

Affiliation

¹ Laboratory of Physical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.

PMID: 16989847
DOI: 10.1016/j.jcis.2006.08.043

Abstract

The adsorption of binary mixtures of cetyltrimethylammonium bromide (CTAB) and cetyldimethylbenzylammonium chloride (CDBACl) at the mercury/electrolyte interface was studied in various electrolyte systems. The optimum surfactant concentration and electrolyte ratio was searched for, to obtain the formation of a condensed film at as wide a potential range as possible at the highest temperature possible. The optimum conditions found were 2 x 10(-4) M CTAB and 2 x 10(-4) M CDBACl in 0.07 M KF and 0.03 M KBr at 2 degrees C. The capacitances vs time curves were used for the reconstruction of isochronous capacitance vs potential curves. These curves showed that in that system the condensed film was formed in the potential range from -0.4 to -1.9 V vs Ag/AgCl in less than 220 s. The stability of this film, following the removal of the mercury drop from the solution, was also studied.