Density of DSILs was determined using an Automatic Density Meter DDM2911 (Rudolph Research Analytical, Hackettstown, NJ) equipped with a Peltier module for precise temperature control, with the mechanical oscillator method. The measurement was acquired at 20 °C in 5 repetitions for each of the samples (approximately 1.0 cm 3 ). Before the series of measurements, the apparatus was subjected to a two-point calibration using deionized water and air as the references. After each series of measurements, the densimeter was washed with water and organic solvents (methanol and acetone) and dried with airflow. The uncertainty of the density measurement was estimated to be less than 5×10 -4 g cm -3 . Based on the experimental density values obtained at 20 °C (ρ20), and average molecular weights of ILs and DSILs (Mw), the following parameters were calculated: molar volume (Vm 20 ), excess molar volume (V E20 ), average volume of a single ionic pair (Vip 20 ), lattice energy (UPOT 20 ), and standard molar entropy (S°2 0 ), according to the equations below :