On the effect of temperature on the dielectric relaxation time of some benzene derivatives and certain of their binary mixtures

On the visco-elastic and dielectric behaviour of two alcohols and their binary mixture

“…The above observation is inconsistent with the literature; namely, from literature [11,13] it can be seen that the results obtained could be explained in the case of certain simple molecules in the light of Debye theory, but they show some serious anomalies in other molecules leading to certain modifications to the Debye equation. In particular, the assumption of linear dependence on viscosity for the relaxation time irrespective of the size and the shape of the surrounding molecules was found to be valid in the case of some simple molecules and surrounded by medium to low viscosity.…”

Thermodynamic parameters of poly(ethylene glycol) from dielectric relaxation studies

“…The relaxation rate depends strongly on the temperature. The theory of thermal activation over potential barrier described by Blythe and Bloor,6 employed by earlier workers16, 19–21 can successfully be adopted to estimate the thermodynamic parameters such as change in molar free energy of activation Δ G , change in molar enthalpy of activation Δ H , and change in molar entropy of activation Δ S . Here, transition of polymer molecule from one state to another, overcoming the potential barrier of certain height takes place.…”

“…For the calculation of the relaxation time τ at any temperature T , the expression for loss tangent tan δ computed by measured values of ε′ and ε″, employing Whiffen and Thompson model, as was done by Sannaningannavar et al19 and Ayachit and coworkers20 was adopted. According to them …”

“…If appropriate frequency of the microwave is under use, then microwave frequencies are capable of influencing the orientation polarization of the polar polymer materials 10–14. The orientation polarization being temperature dependent2, 15–20 helps to obtain meaningful information, like shape, size, and the rotating molecular entities. The molecular dynamics is characterized by the observed values of relaxation times4–9 in microwave frequency region.…”