Preparation and characterization of “clickable” polyaniline derivatives on graphene modified electrodes

Abstract

The electrochemical polymerization of 2- and 3-ethynylaniline and copolymers with aniline was investigated. It is found that 3-ethynylaniline is more reactive than 2-ethynylaniline and, in the presence of aniline it electropolymerizes. The effect of the electrode material on the electropolymerization of 3-ethynylaniline and its copolymers with aniline was studied and graphene-modified electrodes show very good performance for the formation of a PANI-like polymer, as demonstrated by FTIR and Raman measurements. The graphene layer thickness also appears to influence the polymerization, the best results obtained for the thinnest films used. Finally, copolymers of aniline and 3-ethynylaniline were chemically prepared at room temperature. These copolymers display PANI-like structure with alkyne grafted groups and showed good electrochemical response, slightly different to that of the parent PANI with lower electrical conductivity. Preliminary tests indicate that the PANI derivative can be successfully clicked to poly(ethylene glycol) by a thiol-yne click reaction.