A series of nonionic Schiff base surfactants were prepared by the reaction between polyethylene glycol, glyoxalic acid
and phenylene diamine. The prepared compounds were characterized using elemental analysis, FTIR and 1H-NMR
spectroscopy. The surface activities of the prepared nonionic surfactants were determined using surface and interfacial
tension measurements. The thermodynamic properties of these surfactants in adsorption and micellization were
calculated at 25oC. The results showed that the increase in the polyethylene glycol chain length (nonionic chains)
increases their adsorption tendencies at the interface.