Relaxation phenomena of binary polar liquid mixture in C₆H₆ from conductivity of solution measured at 10 GHz electric field

Abstract

The dielectric relaxation times τ _jk ’s and dipole moments µ _jk ’s of the binary (jk) polar mixtures of N,N-dimethyl formamide (DMF) and pyridine dissolved in benzene (i) are estimated using linear slope of σ _jk ″ − σ _ijk ′ curves as well as ratio of slopes of σ _ijk ″ − w _jk and σ _ijk ″ − w _jk curves at w _jk → 0 for different mole fractions τ _jk ’s of pyridine and experimental temperatures under 9.875 GHz electric field. The measured µ _jk ’s and τ _jk ’s agree well with the reported values validating the proposed methods. The solute-solute (dimer) molecular associations are inferred from the plot of τ _jk − x _j and µ _jk − x _j curves for x _j = 0.0 to 0.5 of pyridine and thereafter solute-solvent (monomer) molecular association occurs. The theoretical µ_theo’s are calculated to predict solute-solute and solute-solvent molecular association. The µ _jk − T curves are drawn to show elongation of bond angles and bond moments with temperatures. The thermodynamic energy parameters are calculated from Eyring’s rate theory equations to know the molecular dynamics as well as to ascertain Debye-Smyth relaxation mechanism of the systems.