Viscosity of ILs and DSILs was determined by using a Rheometer RC30-CPS apparatus (RheoTec Messtechnik GmbH, Germany) with cone-shaped geometry (C50-1). The viscosity of the samples (approximately 0.7 cm 3 ) was measured at 20 °C all obtained systems. In addition, viscosities at higher temperatures (30-80 °C) were recorded for the single-anion ILs, as well as for the DSIL with molar ratios of MCPA and dicamba anions of 5:5. The apparatus was calibrated using a calibration standard with the viscosity of 15.664 Pa•s at 20 °C, manufactured