Location of phenothiazine in sodium dodecyl sulfate/n-pentanol/water microemulsions

The location of phenothiazine (PTZ) in sodium dodecyl sulfate (SDS)/n-pentanol (n-C5H11OH)/water microemulsions is studied by cyclic voltammetry at a Pt electrode. The results indicate that PTZ exists in the membrane phase of microemulsion droplets with its N atom or S atom toward the polar head of the surfactant. In addition, we examine the effect of the compositions and structures of the microemulsions, pH, temperature, and the inorganic salts on the location distribution for PTZ in the membrane phase of the microemulsions. The results show that the location distribution for PTZ in the membrane phase of the microemulsions is mainly dependent on the hydrogen bond between the -NH in PTZ and n-pentanol (or the -SO4- of SDS) and on the electrostatic interaction between the S atom (or N atom) in PTZ and the polar head of SDS.