Abstract Methoxy ethyl oleate, a nonionic surfactant, has been investigated at the air/water interface for various surface properties by employing the Langmuir film balance technique. The ester forms an expanded isotherm at the air/water interface. The minimum area of packing (A 0), initial area of increase of surface pressure (A i), collapse pressure (π c), and area/molecule at collapse pressure (A c) have been estimated from the isotherm curve. ...