Capacitive Properties of Modified and Non Modified Thermally Expanded Graphite Composites With Polyaniline

Abstract

Modified thermally exfoliated graphite with p-nitrophenyldiazonium tetrafluoroborate, followed by reduction of nitrophenyl groups to aminophenyl ones. Composites PAN - graphite, PAN - modified graphite at a constant value of potential 1 V were synthesized by electrochemical method. Their conditional density and electrical conductivity were determined. The electrochemical behavior in 1 M HCl solution was investigated and the capacity of synthesized composites was calculated. The conditional density of PAN composites with modified and non modified graphite increases sharply with increasing graphite content from 0 to 5%. At graphite contents higher than 5%, the density of composites varies very slightly. In the range of graphite contents 0% - 20%, the density is the highest for composites with a graphite content of 5% - 10%. In the case of modified graphite, the density of composites is higher than that of composites with non modified graphite. Analysis of the dependence of the specific conductivity on the content of modified graphite indicates that the conductivity of PAN - graphite composites increases the most with increasing graphite content from 1 to 10%. In this interval, the conductivity increases linearly. This indicates the absence of specific interactions between the components in the synthesized composites, as well as the fact that the nature of the distribution of these components does not change with changes in the graphite content. For a composite with modified graphite, there are two maximum capacities of composites with a graphite content of 2 and 10%. For a composite with non modified graphite on the obtained curves there is a maximum capacity of composites with a graphite content of 2%. Modification of the graphite surface leads to increased interaction between the components of the compo¬site, which resulted in the compaction of its structure. As a result, the capacitive characteristics of modified graphite composites, as well as CVA currents and electrical conductivity, were lower compared to composites with non modified graphite.