Conductive mixtures of two non-conducting liquids: octanoic acid and bis(2-ethylhexyl)amine

Dielectric measurements on mixtures of two amphiphiles, octanoic acid (OA) and bis(2-ethylhexyl)amine (BEEA), have been performed at room temperature in the mHz-GHz frequency range, showing that the conductivity of the mixtures can be up to seven orders of magnitude higher than that of the neat liquids [1]. The viscosity of the OA:BEEA mixtures also increases up to four orders of magnitude with respect to the pure components. The observed features might depend on the formation of suitable OA/BEEA adducts [2]. Along with the role of breaking and reforming of hydrogen bonds in the system, steric factors have to be considered in order to account for the observed effect on the conductivity, which is less evident or absent if different binary mixtures of amphiphilic molecules are studied [3,4]. A deeper understanding of the link between the structure of the chosen surfactant molecules, their arrangement at the nanoscale level, and the macroscopic conductivity might help to design novel materials with enhanced performances.