Synthesis of polyethylenimine-functionalized poly(glycidyl methacrylate) magnetic microspheres and their excellent Cr(VI) ion removal properties

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• 作者：Xitong Sun ; Liangrong Yang ; Huifang Xing ; Junmei Zhao ; Xiaopei Li ; Yinbin Huang ; Huizhou Liu
• 关键词：PGMA ; Polyethylenimine ; Cr(VI) ; Adsorption ; Equilibrium
• 刊名：Chemical Engineering Journal
• 出版年：December, 2013
• 年：2013
• 卷：234
• 期：Complete
• 页码：338-345
• 全文大小：1551 K

文摘

Micron-sized polyethylenimine-functionalized poly(glycidyl methacrylate) superparamagnetic microspheres (m-PGMA-PEI) were prepared by a process involving: (1) synthesis of PGMA microspheres using the dispersion polymerization method; (2) ring-opening reaction of epoxy groups on PGMA microspheres with ethylenediamine (EDA) to yield amino groups; (3) in situ coprecipitation of Fe₃O₄ nanoparticles into the pores of microspheres; (4) Michael addition of amino groups with methyl acrylate (MA) to yield ester groups; and (5) amidation of the terminal ester groups with polyethylenimine (PEI). Once generated, the resulting m-PGMA-PEI microspheres were tested for their ability to remove Cr(VI) from an aqueous solution in batch experiments. The results demonstrated that Cr(VI) adsorption was significantly pH dependent. The optimized pH value was 2.0. The adsorption isotherm of the adsorbent fit the Langmuir model, with the maximum adsorption capacity of 492.61 mg/g. The Cr(VI) adsorption rate was rapid, and the adsorption reached equilibrium within 15 min. The thermodynamic parameters (螖G⁰, 螖H⁰, 螖S⁰) demonstrated that the adsorption process was endothermic and spontaneous in nature. The presence of the coexisting anions involving Cl^{鈭?/sup>, , and had no remarkable influence on Cr(VI) adsorption except . The regeneration study proved that the m-PGMA-PEI microspheres could be repeatedly utilized with no significant loss of adsorption efficiency.}