Surfactants adsorption, ITIES

Introduction of the polarized ITIES opened a new stage in the study of adsorption of ionic surfactants, which had been used from the early studies of the ITIES onward [78-81]. 

Mechanical instability of ITIES due to adsorption and chemical desorption of surfactants has been known for many years. For example, Aral et al. studied the instability of the water-octanol interface caused by the adsorption of sodium dodecylsulfate by potentiometry and could relate interfacial polarization and oscillations [79]. The early work has been thoroughly reviewed by Kihara and Maeda [80]. In 2001, Maeda et al. demonstrated that self-sustained oscillations could be studied for a systan comprising cetyltrimethylammonium in water and picric acid in nitrobenzene [81]. 

More recently, this topic has been revisited by Daikhin and Urbakh [88] who presented a kinetic description of ionic surfactant transfer across an ITIES that includes the charging of the interface, adsorption, and transfer as well as characteristics of the electrical circuit. This model showed that the irregular current oscillations are due to a dynamic instability induced by the interplay between the potential-dependent adsorption and direct transfer across the interface. In particular, this model showed that current anomalies occur in a potential range close to the standard ion-transfer potential. 

In a few reports, the interactions of DNA molecules with small organic molecules at the ITIES were investigated by voltammetry to observe the adsorption and desorption of their complexes. Specifically, the intercalations of DNA with A-methylphenantroline and acridine-calix[4]arene were probed voltammetrically by monitoring the transfer of the cationic intercalators. Electrostatic interactions between DNA and dimethyldioc-tadecylammonium at the DCE/water interface gave absorption waves although DNA extraction by the reverse micelles of this surfactant had been reported. ... 

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