The density, dynamic viscosity and kinematic viscosity of protic and aprotic polar solvent (pure and mixed) systems: An experimental and theoretical insight of thermophysical properties

We report herein the thermophysical properties of pure protic and aprotic polar solvents (water, dimethyl sulfoxide and N,N-dimethyl formamide) and their mixed (binary and ternary) systems. The experimental density (ρ) and viscosity (η) were determined for these systems by varying temperature range from 293.15 K to 343.15 K. The excess properties (viz., excess molar volumes (V ^E ), excess thermal expansion coefficient (α _E ), viscosity deviation (Δη) and excess Gibb's free energy (ΔG ^E ) for viscous flow) were computed for mixed systems from experimental values. The excess properties of the mixed systems show clearly a non-ideal behaviour. Especially, a mixture of water with aprotic polar component show better thermophysical properties than pure systems. The pure (DMF) system shows increasing dynamic viscosity values at higher temperature region. Both the binary as well as ternary mixed systems show maximum activation energy (E _a ) in the presence of water depicts their thermal stability of the mixed systems. The thermal expansion coefficient (α) also revealed increase in the thermal behaviour for the protic-aprotic systems. In addition to that, thermodynamic parameters are also evaluated for better understanding of thermal stability.