Dielectric relaxation studies of binary mixtures of N-methylformamide and benzonitrile in benzene solution using microwave absorption data

摘要

Using standard standing wave microwave techniques and following the single frequency (9.885 GHz) concentration variational method, the dielectric relaxation time (tau) and dipole moment (mu) of binary mixtures of different molar concentrations of N-methylformamide (NMF) in the binary mixtures of N-methylformamide (NMF) and benzonitrile (C_6H_5CN) in benzene solutions have been calculated at different temperatures (25, 30, 35 and 40 deg C). The energy parameters (triangle open H_(epsilon), triangle open F_(epsilon), triangle open S_(epsilon)) for the dielectric relaxation process of binary mixtures containing 50 mol percent of NMF have been calculated at different temperatures and comparison has been made with the corresponding energy parameters (triangle open H_(eta), triangle open F_(eta), triangle open S_(eta)) for the viscous flow process. Based on these studies, it is inferred that dielectric relaxation process can be treated as a rate process just like the viscous flow process. Solute-solvent molecular associations have been proposed.