A novel method to prepare chitosan/montmorillonite nanocomposites in the presence of hydroxy-aluminum oligomeric cations

It was shown that chitosan and hydroxy-aluminum pillared montmorillonites were excellent materials for the removal of dyes and metal ions from effluent of dying and finishing. Chitosan, a natural biopolymeric cation, is also a promising candidate to modify montmorillonite as absorbent. Chitosan/hydroxy-aluminum pillared montmorillonite nanocomposites are expected to play a multiplex role in wastewater treatment. In this study, the nanocomposite was synthesized by incorporating hydroxy-aluminum pillared montmorillonite into chitosan solution prepared by dissolving the chitosan into diluted acetic acid. The ratio of chitosan to the cationic exchange capacity of the montmorillonite was about 1:1, 2:1, 3:1, 4:1 and 6:1, respectively. The nanocomposites were characterized by XRD (X-ray diffraction), SEM (scanning electron microscopy) and FT-IR (Fourier transform infrared spectroscopy). The experimental results indicated that the presence of hydroxy-aluminum cation was in favor of the chitosan intercalation and the interlayers of montmorillonites was intercalated with the bilayers of chitosan sheets. The nanocomposites can be used in absorption of organic and metal ions from dying and finishing effluent.