An investigation on molecular dynamics of binary mixtures of N-methylacetamide and tetramethylurea in microwave region

Abstract

The dielectric relaxation times (<i>τ</i>)and the dipole moments (<i>µ</i>) of the binary mixtures of different molar concentrations of tetramethylurea (TMU) in the binary mixtures of N-methylacetamide (NMA) and tetramethylurea (TMU) in benzene solutions have been calculated by using standard standing wave microwave techniques and Gopala Krishna’s single frequency (9.90 GHz) concentration variational method at different temperatures (25 °C, 30 °C, 35 °C and 40 °C)<em>.</em> The energy parameters (<img src='http://www.niscair.res.in/jinfo/delta.gif' border=0><em>H</em>_e, <img src='http://www.niscair.res.in/jinfo/delta.gif' border=0><em>F</em>_e, <img src='http://www.niscair.res.in/jinfo/delta.gif' border=0><em>S</em>_e) for the dielectric relaxation process of binary mixtures containing 30% mole-fraction of TMU have been calculated at the respective given temperatures and the comparison has been made with the corresponding energy parameters (<img src='http://www.niscair.res.in/jinfo/delta.gif' border=0><em>H</em>_η, <img src='http://www.niscair.res.in/jinfo/delta.gif' border=0><em>F</em>_η, <img src='http://www.niscair.res.in/jinfo/delta.gif' border=0><em>S</em>_η) for the viscous flow. On the basis of the observations, it is found that the dielectric relaxation process can be treated as the rate process like the viscous flow process. The solute-solute and solute-solvent types of the molecular associations have been predicted.