Thermophysical properties for the binary mixtures of 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [hmim][Tf2N]Â +Â N-methyldiethanolamine (MDEA) at temperatures (303.15 to 323.15) K

► Densities, viscosities and refractive indices for [hmim][Tf2N] + MDEA are measured. ► Excess properties, thermal expansion coefficients and deviations are deduced from the experimental data. ► Redlich-Kister type of equations are used to correlate the excess properties.