For the first time, the impact of water and metal-oxide nanoparticles (MONPs) on the
electronic structure and optical properties of 1-ethyl-3-methylimidazolium methylsulfate (C 2
mim MS) ionic liquid (IL) is reported. Off-switching of cation-anion interaction and
emergence of new peak at 2970 cm− 1 was observed indicating change in the interaction
strength and conformation of ethyl chain upon dilution. Optical absorption properties and
viscosity of neat IL significantly enhanced by dispersing a very low volume fraction of …