10.1021/jp309661p.s001 Jonas Schenk Jonas Schenk Ulrich Panne Ulrich Panne Merwe Albrecht Merwe Albrecht Interaction of Levitated Ionic Liquid Droplets with Water American Chemical Society 2012 vibrational spectroscopy atmosphere absorption rate spectroscopic data band shifts equilibrium mole fraction alkylsulfate anions hydrogen bond PF type Liquid Droplets BF 4 Raman spectra WaterThe influence analysis 2012-12-06 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Interaction_of_Levitated_Ionic_Liquid_Droplets_with_Water/2463316 The influence of a humid or dry atmosphere on acoustically levitated ionic liquid droplets was studied by volumetric analysis and vibrational spectroscopy. Imidazolium-based ionic liquids with two types of anions, fluorinated (BF<sub>4</sub> and PF<sub>6</sub>) and alkylsulfate anions, were investigated. The amount of absorbed water was correlated with structural differences of the ionic liquids and analyzed in terms of equilibrium mole fraction as well as absorption rate. The type of anion had the most significant influence on the amount of adsorbed water from the atmosphere. Furthermore, spectral changes in the in situ Raman spectra due to absorbed water were studied for all investigated ionic liquids. For 1-ethyl-3-methylimidazolium ethylsulfate, an exemplary detailed analysis of the intermolecular interactions between cations, anions and water was carried out based on the spectroscopic data. The observed band shifts were explained with a hydrogen bond between the anion and water.