Microwave dielectric measurements of binary mixtures of nicotinamide and 1-propanol in benzene solutions at a constant temperature

Abstract

The properties of the binary mixtures of nicotinamide and 1-propanol have been studied at constant temperature 303 K in dilute solutions of benzene at microwave frequency 9.385 GHz. The values of different dielectric parameters namely; static permittivity (ε₀)_,dielectric constant (<img src='http://www.niscair.res.in/jinfo/epsilon-dash1.gif' border=0>), dielectric loss factor (<img src='http://www.niscair.res.in/jinfo/epsilon-dash2.gif' border=0>)and optical permittivity (ε_∞) have been determined for five different mole fractions of nicotinamide in 1-propanol. The values of permittivity and dielectric loss are used to evaluate relaxation time for overall molecular rotation (<img src='/image/spc_char/tow.gif' border=0>₁), relaxation time for intramolecular rotations (<img src='/image/spc_char/tow.gif' border=0>₂), most probable relaxation time (<img src='/image/spc_char/tow.gif' border=0>₀) and dipole moment (<img src='/image/spc_char/micro.gif' border=0> ) at a constant temperature. Different values of relaxation times are found to increase with the mole fraction of nicotinamide in all binary mixtures while the values of dipole moment decrease with the increase in the mole fraction of nicotinamide. The energy parameter (Δ<i>F</i>_ε) for dielectric relaxation process of the mixtures is also calculated which increases with the mole fraction of nicotinamide. It is found that the dielectric relaxation process can be treated as a rate process. Present investigations suggest the existence of both the intramolecular and overall orientation in the binary mixtures.