An investigation on molecular dynamics of binary mixtures of Nmethylformamide and Ethanol in microwave region

摘要

The dielectric constant (e¢ ) and dielectric loss (e² ) of the binary mixtures of N-methylformamide and Ethanol have been calculated at 9.883GHz by using standard standing microwave techniques. Gopalakrishna’s single frequency concentration variation method has been used to calculate dipole moment (m) and dielectric relaxation time (t) for different mole-fractions of NMF in the binary mixture at different temperatures of 250C, 300C, 350C and 400C. The variation of dielectric relaxation time with the mole-fraction of NMF in the whole concentration range of the binary mixtures was found to be non-monotonic. The solute-solute and solutesolvent type of molecular associations may be proposed based upon above observations. Using Eyring rate equations the energy parameters (DH,DF,DS ) for the dielectric relaxation process and the viscous flow process have been calculated. It is found from the comparison of energy parameters that just like the viscous flow process the dielectric relaxation process can also be treated as the rate process.