Frequency and Temperature Dependence of Ethanol Using the Cole-Cole Relaxation Model

The dielectric constant and loss factor of pure ethanol was analyzed using the Cole-Cole relaxation theory for a temperature range 10°C - 50°C and frequency spectrum of 100kHz to 50MHz, The values obtained were plotted against the frequency and temperature respectively. At the lower rung of the frequency spectrum, the dielectric constant was high and uniformly decreased as the frequency increased until it gets to saturation at 50MHz. The loss factor have peaks of 4.59 at 100kHz and temperature 10°C, 4.38 at 600kHz and temperature of 20°C, 3.97 at 1100kHz and 30°C, 3.68 at 1500kHz and 40°C and 3.40 at 2000kHz and temperature of 50°C. The peaks correspond to the relaxation points at the various frequencies listed. For the temperature dependence, the dielectric constant showed a decrease as the temperature increased for a frequency range of 100 - 500kHz, maintained an almost constant value of dielectric constant for a frequency of 1000kHz then increase weakly as the temperature increased for a frequency range of (2000kHz - 50MHz). The dielectric constant showed a slow response to temperature change while the loss factor showed a quick response to temperature change because it is a temperature sensitive parameter compared to the dielectric constant. An analysis of real and imaginary parts of dielectric permittivity has been elucidated using Cole-Cole plot of the complex permittivity. With the aid of the Cole-Cole plot, the values of static dielectric constant (es), optical dielectric constant (e∞) were determined within the frequency and temperature range of interest. The values obtained were in agreement with standard measurements.