Electrodeposition of Poly(3-hydroxyaniline) from Acidic Aqueous/Acetonitrile Solution

Electrodeposition of poly (3-hydroxyaniline) on platinum electrode from acidic/acetonitrile medium was carried out using cyclic voltammetry technique. The kinetic parameters were calculated by means of ex-situ microgravimetric and electrochemical data. The experimentally obtained kinetic equations were R_P,W = k_W acid]^0.91 monomer]^1.2 electrolyte]^0.69 from microgravimetric data and R_P,E = k_Eacid]^0.92 monomer]^0.96 electrolyte]^0.7 from the values of the anodic current density using cyclic voltammetry technique. The apparent activation energy was calculated by the two techniques and is found to be 145.5 and 143.6 kJ/mol from microgravimetric and electrochemical data, respectively. The mechanism of the electrochemical polymerization reaction has been discussed and thermogravimetric analysis (TGA) is used to confirm the proposed structure and determination of the number of water molecules in the polymeric chain unit.