Comparisions of the effects of temperature on the W/O microemulsions formed by alkyl imidazole gemini and imidazole ionic liquids type surfactants

Abstract

ABSTRACTThe thermodynamic and structural parameters of the W/O microemulsion systems 12-4-12(a), C12mimBr(b) + butan-1-ol + octane + 5% NaCl solution were studied and compared at different temperatures. The thermodynamic properties of the mixed surfactants W/O microemulsions 12-4-12/SDS(a), C12mimBr/SDS(b) + butan-1-ol + octane + 5% NaCl solution were also studied at different temperatures. They were compared with each other and compared with the above W/O microemulsions containing the single surfactant. In the mixed-surfactants W/O microemulsions, both (the mole fraction of the alcohol in the oil phase) and (the mole fraction of the alcohol in the interfacial layer) are significantly lower, while is significantly higher, compared with the W/O microemulsions containing the single surfactant. As temperature increases, decreases while both and increases. The standard enthalpy change () and entropy change () of transferring alcohol from the continuous oil phase to the interfacial layer are all negative in value. The order of magnitude for both and values is as follows: 12-4-12/SDS < C12mimBr/SDS < 12-4-12 < C12mimBr. As temperature increases, values slightly decrease, while values slightly increase. This leads to the decrease of the values.