Synthesis and properties of amide-based cationic gemini surfactants with semi-rigid spacer

Abstract A series of novel gemini surfactants (m-E2Ph-m) with ester groups and a benzene ring as rigid spacer were synthesized and characterized by IR, 1H NMR and Mass spectrometry. The effect of hydrophobic chain length on the surface properties and aggregation behavior of the gemini surfactants were investigated by the measurements of surface tension, electrical conductivity, fluorescence. The critical micelle concentration (CMC) of these surfactants decreases with increasing alkyl chain length. The thermodynamic parameters exhibited that the micellization was a spontaneous and exothermic process in environment. The micellization process became more beneficial with the increase of alkyl chain length and the decrease of temperature.