Organofunctionalized kenyaite for dye removal from aqueous solution

Crystalline layered sodium kenyaite was exchanged to proton kenyaite when reacted with hydrochloric acid solution, providing a new surface with available silanol groups that are able to couple with N-3-tri-methoxysilylpropylethylenediamine silylating agent, after prior expansion of the basal distance with the polar organic solvent dimethyl sulfoxide. The resulting organofunctionalized nanomaterial (2N-Ken) was characterized by elemental analysis, infrared spectroscopy, X-ray diffraction, carbon and silicon nuclear magnetic resonances in the solid state, surface analysis, porosity, thermogravimetry, and electron scanning microscopy. The quantity of silylating agent incorporated into the nanospace, calculated from the nitrogen elemental analysis, was determined as 0.48 mmol g(-1), after expanding of the acidic precursor basal distance from 1.62 to 1.99 nm. The presence of a covalent silicon-carbon bond of the organosilyl moiety on the inorganic layered structure was confirmed through nuclear magnetic resonance. This new nanomaterial has the ability to extract the Sumifix Brilliant Orange 3R textile dye from aqueous solution, using a batchwise process. The effects of stirring time, adsorbent dosage, and pH on the adsorption capacity demonstrated that 4 h is enough to reach equilibrium at 298 +/- K under pH 4.0. Based on error function values (F-error) the data were best fitted to fractional-order and chemisorption kinetic models when compared to pseudo-first-order and pseudo-second-order kinetic models. The equilibrium data were better fitted to the Sips isotherm model. (C) 2009 Elsevier Inc. All rights reserved.