Magnetic polyaniline nanocomposites toward toxic hexavalent chromium removal

The removal of toxic hexavalent chromium (Cr(VI)) from polluted water by magnetic polyaniline (PANI) polymer nanocomposites (PNCs) was investigated. The PNCs were synthesized using a facile surface initiated polymerization (SIP) method and demonstrated unique capability to remove Cr(VI) from polluted solutions with a wide pH range. Complete Cr(VI) removal from a 20.0 mL neutral solution with an initial Cr(VI) concentration of 1.0–3.0 mg L21 was observed after a 5 min treatment period with a PNC load of 10 mg. The PNC dose of 0.6 g L21 was found to be sufficient for complete Cr(VI) removal from 20.0 mL of 9.0 mg L21 Cr(VI) solution. The saturation magnetization was observed to have no obvious decrease after treatment with Cr(VI) solution, and these PNCs could be easily recovered using a permanent magnet and recycled. The Cr(VI) removal kinetics were determined to follow pseudo-first-order behavior with calculated room temperature pseudo-first-order rate constants of 0.185, 0.095 and 0.156 min21 for the solutions with pH values of 1.0, 7.0 and 11.0, respectively. The Cr(VI) removal mechanism was investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and energy-filter transmission electron microscopy (EFTEM). The results showed that PANI was partially oxidized after treatment with Cr(VI) solution, with Cr(VI) being reduced to Cr(III). The EFTEM observation indicated that the adsorbed Cr(III) had penetrated into the interior of the PNCs instead of simply adsorbing on the PNC surface. This synthesized material was found to be easily regenerated by 1.0 mol L21 p-toluene sulfonic acid (PTSA) or 1.0 mol L21 hydrochloric acid (HCl) and efficiently reused for further Cr(VI) removal.

• Autores: Colorado Lopera, Henry Alonso; Gu, Hongbo; Rapole, Sowjanya B.; Sharma, Jaishri; Huang, Yudong; Cao, Dongmei; Luo, Zhiping; Haldolaarachchige, Neel; Young, David P.; Walters, Bryan; Wei, Suying; Guo, Zhanhu
• Tipo de recurso: Article of investigation
• Fecha de publicación: 2012
• Institución: Universidad de Antioquia
• Repositorio: Repositorio UdeA
• Idioma: eng
• OAI Identifier: oai:bibliotecadigital.udea.edu.co:10495/46628
• Acceso en línea: https://hdl.handle.net/10495/46628
• Palabra clave: Polianilinas; Polyanilines; Nanocompuestos (materiales); Nanocomposites (Materials); Polimerizacion; Polymerization; http://id.loc.gov/authorities/subjects/sh2014002578; http://id.loc.gov/authorities/subjects/sh2008002284; https://id.nlm.nih.gov/mesh/D058105
• Rights: openAccess
• License: http://creativecommons.org/licenses/by-nc/4.0/