Electrosynthesis and characterisation of poly(safranine T) electroactive polymer films

The phenazine safranine T has been electropolymerised by potential cycling at carbon film electrodes in nitrate-containing solutions at different pH: 2.0, 5.5, and 7.0, as well as from chloride solution, pH 5.5. The electroactive polymer obtained, poly(safranine T), has been analysed by cyclic voltammetry in different electrolyte solutions and its morphology examined using scanning electron microscopy. The surface coverage was calculated and found to be the highest for the film formed in chloride solution, pH 5.5, with 8.7 nmol cm− 2. The other films had lower coverages, from 5.3 to 7.8 nmol cm− 2, and are similar to those obtained for other phenazine dye polymers. Although the fastest polymerisation occurred in solutions at pH 5.5, the best electrochemical properties resulted from electropolymerisation at pH 2.0. Analysis of the cyclic voltammograms showed that in most cases the electrochemical processes at the polymer coated electrodes are limited by surface reactions. Scanning electron microscopy data confirmed the results obtained by cyclic voltammetry and showed that the most compact film was obtained in chloride solution.