Effect of biochar binding on dielectric properties of color catcher sheets

The dielectric properties in the frequency range of 102 to 106 Hz and at the temperatures of 30 to 60 °C of 0.4 mm thick color catcher sheets (nonwoven textile with ion exchange properties) both in the native state and with bound biochar were investigated using the oscilloscope method. The sample dimensions were 11 cm. To assess the influence of the sample thickness, samples with several (maximum 4) layers were used together with one-layer textile. It was shown that, unlike the data obtained by us earlier, the dielectric properties of the nonwoven textile without additives are caused by near-electrode processes. It was demonstrated as well that in this case, the dispersion of the frequency dependences of inverse resistance (analog of the imaginary component of complex dielectric permittivity) with respect to capacitance (analog of the real component of complex dielectric permittivity) corresponds to the Debye dispersion. Using the obtained results, the dielectric relaxation time (2.4·10–5 s) and the thickness of the near-electrode layer (1.5 ?m) were estimated. Measurements at different temperatures and with several layers of the native textile demonstrated that the parameters of this relaxation process do not depend on both the sample thickness and the temperature. It was found that the sample resistance decreased by 3 orders of magnitude on average in the presence of biochar bound to the textile. In this case, the temperature dependence of the inverse resistance (analog of conductivity for uniform and continuous bodies) obeyed the Arrhenius law. The activation energy of the temperature dependence of the inverse resistance was 0.37 eV, which is greater than the similar value obtained in our work of 2024.