Abstract
A series of nonionic Schiff base surface active agents were prepared by the reaction between polyoxyethylene, glyoxalic acid and phenylene diamine. The compounds structures were described by means of micro-elemental analysis, infrared and proton magnetic resonance spectroscopy. The surface activities of the synthesized nonionic surface active agents at the interface were defined using the measurements of surface and interfacial tension. The thermodynamic properties of these surface active agents during adsorption and micellization processes were calculated at 25 °C. The results showed that the increase in the polyoxyethylene chain length (nonionic chains) increases their adsorption tendencies at the interface. The biological activities of the different nonionic surface active agents were measured in terms of inhibition zone diameter and rationalized to their chemical structures and surface activities.
•Three nonionic di-Schiff base surfactants were prepared.•The surfactants can be used in antimicrobial field.•The antimicrobial efficiencies were high towards the microbial growth.•The activity was increased by decreasing the nonionic chain length.