Polyaniline (PAn) doped with dodecylbenzenesulfonic acid (DBSA) was synthesized by emulsion polymerization using ammonium persulfate (APS) as an initiator in the presence of a constant magnetic field (0.6 T). The effects of magnetic field, the concentrations of APS, DBSA and the reaction temperature on the film formation of PAn doped with DBSA were discussed by the quartz crystal microbalance (QCM) technique. The experimental result showed that via the plot of the PAn film growth rate versus the magnetic field intensity the growth rate increased with the increasing magnetic intensity. The kinetic orders were obtained by the relationship between the concentrations of the reactants and the film growth rate. The activation energy calculated from the temperature dependence of the growth rate was 41.08 kJ/mol. The UV-visible spectra of the PAn polymerization were measured and compared to the polymerization process of the PAn using the QCM technique. The result showed that the absorption intensity of the PAn polymerized in the presence of a magnetic field was greater than that of the PAn polymerized in the absence of a magnetic field at the same time.

Key words: polyaniline, kinetics, magnetic field, quartz crystal microbalance (QCM)