Single step modification of micrometer-sized polystyrene particles by electromagnetic polyaniline and sorption of chromium(VI) metal ions from water

This article describes a single-step reproducible approach for the surface modification of micrometer-sized polystyrene (PS) core particles to prepare electromagnetic PS/polyaniline–Fe₃O₄ (PS/PANi–Fe₃O₄) composite particles. The electromagnetic PANi–Fe₃O₄ shell was formed by simultaneous seeded chemical oxidative polymerization of aniline and precipitation of Fe₃O₄ nanoparticles. The weight ratio of PS to aniline was optimized to produce core–shell structure. PS/PANi–Fe₃O₄ composite particles were used as adsorbent for the removal of Cr(VI) via anion-exchange mechanism. The composite particles possessed enough magnetic property for magnetic separation. The adsorption was highly pH dependent. Adsorption efficiency reached 100% at pH 2 in 120 min when 0.05 g of composite particles was mixed with 30 mL 5 mg L^?1 Cr(VI) solution. The adsorption isotherm fitted best with Freundlich model and maximum adsorption capacity approached 20.289 mg g^?1 at 323 K. The prepared composite was found to be an useful adsorbent for the removal of soluble Cr(VI) ions. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47524.