Effects of FeCl3/ammonium persulfate composite oxidant and magnetic field on film growth rate of polyaniline doped with dodecylbenzenesulfonic acid

Polyaniline (PANI) doped with dodecylbenzenesulfonic acid (DBSA) was synthesized by emulsion polymerization using FeCl₃/ammonium persulfate (APS) as composite oxidant. The effects of different magnetic field (MF) intensities, the molar ratios of FeCl₃/APS, and the concentrations of DBSA on the film growth rate of PANI were analyzed by using a quartz crystal microbalance (QCM) technique. The film growth rate of PANI increased with increasing MF intensity and the concentration of DBSA. However, the film growth rate of PANI decreased with increasing molar ratio of FeCl₃/APS. The polymerization conditions were optimized tentatively by cyclic voltammetry (CV) testing. The peak currents and conductivity were the largest for PANI prepared under the following conditions: MF intensity 0.4 T, molar ratio of FeCl₃/APS 2:1, and concentration of DBSA 0.05 mol/L. The UV–Vis spectra of the PANI polymerization showed that the absorption intensity of PANI polymerized in the presence of MF was greater than that of PANI polymerized in the absence of MF, at the same reaction time.