Effective Adsorption of Heavy Metal Cations by Superparamagnetic Poly(aniline-co-m-phenylenediamine)@Fe3O4 Nanocomposite

The development of simple methods for the removal of heavy metal cations from water samples is a relevant field of research. For this purpose, poly(aniline-co-m-phenylenediamine) (PAMpDA) was synthesized via radical oxidation polymerization of aniline with m-phenylenediamine. Then, superparamagnetic poly(aniline-co-m-phenylenediamine)@Fe3O4 (PAMpDA@Fe3O4) nanocomposite was fabricated from PAMpDA, Fe(II), and Fe(III) salts via the in situ coprecipitation technique. The products were characterized in terms of chemical structure, morphology, thermal and magnetic properties by Fourier transform infrared, X-ray diffraction, scanning electron microscopy, thermal gravimetric analysis, and vibrating sample magnetometer, respectively. The capability of PAMpDA and its nanocomposite for the removal of Pb(II), Cd(II), and Co(II) ions was investigated at various contact times, absorbent dosages, pH, and initial concentrations. The experimental data for Co(II) cation with the highest sorption were analyzed by two isotherms and kinetic equations. In addition, the electrical conductivity of PAMpDA and PAMpDA@Fe3O4 nanocomposite was examined after sorption of the heavy metal ions.