Composition dependent density of ternary aqueous solutions of ionic surfactants and salts

Abstract Surfactants exist in atmospheric aerosols mixed with inorganic salts and can significantly influence the formation of cloud droplets due to bulk–surface partitioning surface tension depression. To model these processes, we need continuous parametrizations concentration dependent properties aqueous surfactant–salt solutions for full composition range from pure water surfactant or salt. We have developed density functions based on pseudo-separation method Young’s mixing rule apparent partial molal volumes that mimic marine environments. The framework requires only parameters binary water–salt water–surfactant systems includes effect salinity micellization composition-dependent critical micelle (CMC). evaluate different models data available literature find most suitable representations volume sodium chloride (NaCl) CMC selected surfactants NaCl solutions. compare results experimental data, obtained additional measurements, containing one ionic octanoate, decanoate, dodecanoate dodecylsulfate relative ratios. Our follows trends increasing densities concentrations ratios both, below above CMC, capturing salt micellization.