High-performance reactive silver-ion adsorption and reductive performance of poly(N-methylaniline)

Self-assembled poly(N-methylaniline) (PNMA) microspheres were prepared in a facile way by an unstirred polymerization of N-methylaniline monomers with ammonium persulfate as an oxidizing agent at different temperatures. The polymers were characterized by FTIR and UV-vis spectroscopy, SEM, TEM and wide-angle X-ray diffraction. Furthermore, adsorption property of PNMA microspheres for silver ions from aqueous solution was investigated by batch experiments. The results revealed that PNMA showed a high-performance adsorption for silver ions by chelation and redox reaction. The maximum adsorption capacity was up to 2.460g/g for silver ions on PNMA microspheres prepared at 0 degrees C, at an initial silver ion concentration of 160mmol/L at 25 degrees C for 48hr. The adsorption process fits the pseudo-second-order kinetics and Freundlich isotherm models. Moreover, the PNMA microspheres exbihit high reductive performances for Au(III) and Pd(II) ions. Therefore, the PNMA microspheres have great potential application in removal and recovery of metal ions from industrial wastewater.