Synthesis and characterization of physicochemical properties of hydrophilic imidazolium-based ionic liquids

A series of ionic liquids based on Octyl and Decyl methylimidazolium with different anions such as chloride, glycinate, dihydrogen phosphate and trihydrogen diphosphate, were synthesized and characterized by 1 HNMR and elemental analysis. IL containing trihydrogen diphosphate anion, was synthesized for the first time. Physicochemical properties, including density, viscosity, surface tension, refractive index, and pH, were measured in temperature range 283.15 to 363.15 K and atmospheric pressure. The effects of temperature, alkyl chain, and anion type on physicochemical properties were investigated. The results revealed that the physicochemical properties decreased as a function of temperature. Unlike viscosity, other properties, such as density, surface tension, refractive index and pH values, decreased, while alkyl chain length increased. Understanding ILs properties and determining their unique abilities helps researchers to use them in new applications. These long alkyl chain ILs, are being used as surfactants to reduce Oil/Water interfacial tension in EOR process.