The evaluation of the behaviour at the air/water mixtures interface of a new series of oligoethoxylated monoalkyled F-alkyl α-bromoesters of general formula RF-CHBr-CO-O-(C2H4O)2-RH has been investigated at 20°C by measurement of surface tension (γs) of the water/ethanol surfactant solution. Critical micelle concentrations (CMC), surface excesses (Γ) and molecular areas (A) have been obtained from these measurements. The study of these physicochemical parameters allowed us to establish the relationship between the surfactant molecular structure and its interfacial properties. In addition we have studied in this work the variation of γs, CMC and Γ with the amount of ethanol used in the mixed ethanol/water solvent. This study allowed us to determine by extrapolation the theoretical values of γs, CMC and Γ in pure water, which could not be obtained experimentally regarding the low solubility of these surfactants in water.
B. Jedidi Yaïch, K. Debbabi, R. Naejus, C. Damas, R. Coudert, A. Baklouti
F-alkyl, oligoethoxylated, nonionic surfactants; solution behaviour; surface properties