کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
612106 | 880691 | 2007 | 10 صفحه PDF | دانلود رایگان |
Water purification is of extreme importance worldwide. p-Nitrophenol was used as a test chemical to design and test an organoclay for the removal of p-nitrophenol from an aqueous solution. Synthesis of the organoclay with methyltrioctadecylammonium bromide [CH3(CH2)17]3NBr(CH3) labeled as MTOAB results in multiple expansions of the montmorillonite clay from 1.24 nm to a maximum of 5.20 nm as is evidenced by the XRD patterns. Thermal analysis shows strong bonding of the surfactant to the clay siloxane layers and the interaction of the p-nitrophenol with the clay surfaces. It is proposed that the p-nitrophenol penetrates the siloxane layer of the clay and bonds through the ditrigonal space of the siloxane hexagonal units to the inner OH units. Such a concept is supported by the observation of an additional infrared band at 3652 cm−1 for the organoclay. Shifts in the p-nitrophenol OH stretching vibrations mean a strong interaction of the p-nitrophenol molecule. Significant changes in the siloxane stretching bands are also observed.
The mechanism of adsorption of p-nitrophenol on both nontreated montmorillonite and surfactant intercalated montmorillonite was studied by X-ray diffraction, thermogravimetry, and infrared spectroscopy. On the untreated and low CEC intercalated montmorillonite the p-nitrophenol adsorbed on the cation hydration sphere. At high CEC values the p-nitrophenol replaced the surfactant cation in the interlayer and bonded directly to the siloxane surface.Figure optionsDownload as PowerPoint slide
Journal: Journal of Colloid and Interface Science - Volume 314, Issue 2, 15 October 2007, Pages 405–414