Spectroscopic study of nanocomposites based on PANI and carbon nanostructures for pH sensors

Nanocomposites of polyaniline (PANI) and two carbon nanostructures - multiwall carbon nanotubes (MWCNTs) and graphene G) were obtained by electrochemical polymerization. PANI based nanocomposites with different concentration of carbon nanostructures (CNS:1, 2 and 3wt%) as well as with different methods for CNS dispersion in the electrolyte, were synthesized. The interactions among the CNS nanostructures and polyaniline matrix were studied and the results confirmed strong interactions among the quinoidal structure of PANI and both CNS. In order to design nanocomposite sensors, PANI/CNS nanocomposites were directly electro-polymerized on gold wires of screen printed electrodes. Their sensing activity was evaluated through the resistivity changes at different pH.