Density and Surface Tension Measurements of Imidazolium-,Quaternary Phosphonium-,and Ammonium-Based Room-Temperature Ionic Liquids:Data and Correlations

摘要

Presented are experimental densities and surface tensions of imidazolium-,quaternary ammonium-,and phosphonium-based room-temperature ionic liquids(RTILs)in the temperature range of(298 to 350)K.Densities of the RTILs decrease slightly with temperature in the studied range(298 to 333)K.At 298 K,the densities of the phosphonium-based RTILs ranged from(0.88 to 1.05)g·cm~(-3),while those of the ammonium-based RTILs ranged from(1.08 to 1.37)g·cm~(-3).The volume expansivities of phosphonium and ammonium RTILs at 1 arm and 298 K are in the range of(5.5 to 6.5)·10~(-4)K~(-1).Surface tension and temperature relationships were established using the van der Waals-Guggenheim equation,sigma=E~s(1-T/T_c)~n,where n approx=1,for the RTILs studied.The Macleod-Sugden-Wright(MSW)equation was used to correlate surface tension with the respective molar volume of the various RTILs.The developed equation can accurately correlate surface tension for this grouping of RTILs with a maximum estimated error of 0.15% within the temperature ranges considered.