Homogeneous phase synthesis of chitosan silica hybrid materials in ionic liquid medium and adsorption of Fe(III) from aqueous solutions

Two chitosan silica hybrid materials were prepared by a two-step process in 78–84% yields using the homogeneous phase reaction of 3-(triethoxysilyl)propyl isocyanate with chitosan dissolved in 1-n-butyl-3-methylimidazolium chloride ionic liquid (∼10% w/w), which was followed by NH₄OH catalyzed hydrolysis of triethoxysilyl groups and then sol-gel process. These new hybrid materials were shown to adsorb up to about 95% of Fe³⁺ from 5 × 10⁻⁴ M aqueous solution at room temperature in 24 h.