Factors influencing electrochemical release of 2,6-anthraquinone disulphonic acid from polypyrrole

Abstract Polypyrrole-2,6-anthraquinone disulphonic acid (PP/AQSA) was prepared galvanostatically from an aqueous solution containing 0.25 M pyrrole and 0.25 M AQSA. Elemental analysis confirmed AQSA incorporation with a loading of 41 mg AQSA/100 mg polymer. PP/AQSA deposited onto reticulated vitreous carbon cartridges was placed into a flow through electrochemical reactor cell for release studies. The release of AQSA was stimulated by the application of negative potentials to the polymer. Electrochemical release was also affected by the ionic strength, pH and the nature of the solvent into which AQSA was released. It was found that the rate of release increased with increasing negative potentials, ionic strength and pH of the solution. The maximum rate of release was obtained in a solution containing acetonitrite-water mixtures (50/50 v/v). It was found that only 17% of the AQSA incorporated into the polymer could be released in 0.1 M NaCl after 1.5 h with an applied potential of −0.80 V.