Investigation of interaction between polyethylene oxide and ionic liquid 1-octyl-3-methyl-imidazolium bromide in aqueous solutions by spectroscopic and viscometric methods

The effect of ionic liquid, 1-octyl-3-methyl imidazolium bromide on the thermodynamic quality of water for polyethylene oxide was studied at the temperature range of 288.15-313 K by viscometric method. The obtained data reveal that thermodynamic quality of water for polyethylene oxide is increased by addition of 1-octyl-3-methyl imidazolium bromide. The flow activation energy was determined and correlated in terms of polymer concentration. The sign of initial slope of the activation energy versus polymer concentration at zero concentration indicates that the thermodynamic quality of ionic liquid aqueous solutions is reduced by increasing temperature. Also, the type of interaction between polyethylene oxide and 1-octyl-3-methyl imidazolium bromide was investigated by FT-IR and UV-Vis spectroscopy methods. The results of FT-IR and UV-Vis spectroscopy confirmed the existence of hydrogen bonding between imidazolium cation and oxygen atom of polyethylene oxide.