Small volume determination of the viscosity-density product for ionic liquids using quartz crystal harmonics

Data for the physical properties of room temperature ionic liquids (RTIL) as a function of chemical composition is limited, owing to the expense and difficulty of producing large volumes of pure samples for characterization. In this work we demonstrate that the viscosity-density values, obtained using impedance analysis of a quartz crystal microbalance are consistent with those obtained using a viscometer and density meter, but only requires a sample volume two orders of magnitude smaller. We also demonstrate that the third harmonic yields closest correlation out of all the harmonics from the fundamental to the eleventh.