Micellization of decyldimethylbenzylammonium chloride at various temperatures studied by densitometry and conductivity

Abstract

The critical micelle concentration (cmc), ionization degree of micellization, β, and standard free energy of micellization, Δ G 0 m, of decylbenzyldimethylammonium chloride in aqueous solution at 15, 25, 35, 45 and 55°C have been estimated from conductivity data. A shallow minimum of the cmc value appears at around 35°C. The apparent molar volumes of the monomeric and micellized surfactant were estimated from density data measured at 15, 25 and 35°C. It is suggested that release of water molecules from the hydration shell of the counter-ions may be an important contribution to the observed apparent expansion of the surfactant upon micellization.