Dielectric dispersion study of binary mixtures of methyl ethers with water at 298.15 K using frequency domain technique

A precision LCR meter along with a liquid dielectric cell have been used to measure the capacitance and resistance of the binary mixtures of methyl ethers with water at 298.15 K in the frequency range of 20 Hz to 2 MHz. The measured values are used to compute the complex dielectric permittivity ε*(ω). The parameters like complex electrical modulus M*(ω), complex electrical conductivity σ*(ω) and loss tangent (tan δ) are obtained from the complex dielectric permittivity values of the samples. The values of excess dielectric permittivity of the samples are calculated using the respective static dielectric permittivity values. The refractive indices of all the samples were measured using Abbe’s refractometer at 298.15 K. All these parameters are used to gain insight into the concentration dependent variation in dielectric and electrical properties of the binary mixtures. A dominance of electrode polarization effect in the lower frequency region is observed for all the samples studied here

Dielectric relaxation and molecular interaction study of aqueous amides

Dielectric permittivity spectra of amides (DMF and DMA) over entire concentrations with aqueous solution have been measured with different frequency ranges at 25 °C. The permittivity spectra of amide-water mixtures at lower frequencies (20 Hz to 2 MHz) have been measured using Agilent Precision LCR meter E4980A and the same have been measured at higher frequencies using time domain reflectometry technique in the frequency range of 10 MHz to 30 GHz. The permittivity spectra have been fitted in Cole-Davidson model in order to evaluate the dielectric parameters. Further the Excess permittivity, Kirkwood correlation factor, Bruggeman factor have been calculated to study the molecular interactions in amides with water molecules. The study has been extended to confirm the molecular interactions among the unlike molecules using the volumetric properties