Adsorption of Ni(II) ions on colloidal hybrid organic-inorganic silica composites

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• 作者：Rattiya Singhon ; Jé ; rô ; me Husson ; Michael Knorr ; Boris Lakard ; Myriam Euvrard ; ^{myriam.euvrard@univ-fcomte.fr}
• 关键词：Silica ; Chitosan ; Adsorbent ; Surface grafting ; Nickel ; Adsorption isotherms
• 刊名：Colloids and Surfaces B ; Biointerfaces
• 出版年：2012
• 期刊代码：14_09277765
• 类别：ms
• 出版时间：1 May, 2012
• 卷：93
• 期：Complete
• 页码：1-7
• 文件大小：623 K

摘要

Two new silica-based composites were prepared as adsorbents for the capture of Ni(II) ions. The first strategy consists in coating chitosan on colloidal fumed silica after acidic treatment yielding the composite SiO₂ + CS. The second route involves in a first step surface condensation of triethoxysilylbutyronitrile, followed by acidic hydrolysis of the surface-bound nitrile groups affording silica particles covered by carboxylic group. In a third step, chitosan has been grafted on the surface-bound C(O)OH groups yielding the composite SiO₂(CO₂H) + CS. The novel hybrid materials were characterized by IR spectroscopy, scanning electron and AFM microscopy, and zeta potential measurements. Batch experiments were conducted to study the sorption performance of these composites for Ni(II) removal from aqueous NiCl₂ solution at different pH. Both Langmuir, Freundlich, and Temkin isotherm models provide good fits with the experimental data. It was shown that these low-cost materials present a promising capacity to adsorb Ni(II) ions. At pH 7, the maximum adsorption capacity q_maxof Ni(II) on the adsorbent, is found to be 182 mg g^鈭? for SiO₂ + CS, and 210 mg g^鈭? for SiO₂(CO₂H) + CS.