Electrical Properties of Partial Carbonized Nanoporous Resin Based on Resorcinol-Formaldehyde

Organic xerogel compounds were prepared by sol-gel method from resorcinol-formaldehyde mixtures in acetone using picric acid as catalyst. The electrical properties of the obtained nanoporous carbon structures were explored by changing the pyrolysis temperature. In this study, the electrical conductivity σ can be expressed as σ=σ^sub 0^exp(-E^sub σ^/kT), where E^sub σ^ depends on the carbonized temperature. The dc and ac conductivities of the obtained amorphous carbon have been investigated from 80 degrees Celsius to 300 degrees Celsius and in the frequency range between 40 Hz and 10^subp 6^ Hz for samples pyrolysed at different temperatures in the insulator-metal transition range. The temperature dependence of samples pyrolysed at low temperatures (T^sub p^=600 degrees Celsius-675 degrees Celsius) follows a Mott law, whereas samples pyrolysed at high temperature (Tp=1,000 degrees Celsius) show an Arrhenius dependence.