Surface activity of mixtures of narrow‐range distributed alcohol oxyethylates and sodium dodecylbenzenesulfonate

Surface and interfacial tension, emulsion inversion temperature, and detergency were determined for mixtures of sodium dodecylbenzenesulfonate and narrow‐range distributed alcohol C 12 −C 14 oxyethylates of different hydrophilicity. The mixtures of ionic and nonionic surfactants behave similarly to nonionic and ionic surfactants at the air/water and hydrocarbon/water interfaces, respectively. The air/water interface is mainly occupied by nonionic surfactant molecules. However, the interfacial tensions for mixtures of nonionic and ionic surfactants are similar to those of sodium dodecylbenzenesulfonate. Mixtures of narrow‐range distributed oxyethylates and sodium dodecylbenzenesulfonate have a higher detergency at 40°C than individual components.