Changes in the surfaces of adsorbed p-nitrophenol on methyltrioctadecylammonium bromide organoclay--an XRD, TG, and infrared spectroscopic study.
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 [CH(3)(CH(2))(17)](3)NBr(CH(3)) 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.
Zhou
Qin
Q
Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China.
Frost
Ray L
RL
He
Hongping
H
Xi
Yunfei
Y
D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry*; D001546:Bentonite / Q000737:chemistry; D001965:Bromides / Q000737:chemistry*; D002627:Chemistry, Physical / Q000379:methods; D000077215:Clay; D009596:Nitrophenols / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry; D013055:Spectrophotometry, Infrared; D013499:Surface Properties; D013696:Temperature; D013818:Thermogravimetry / Q000379:methods; D014961:X-Ray Diffraction
D000538:Aluminum Silicates; D001965:Bromides; D009596:Nitrophenols; D000644:Quaternary Ammonium Compounds; D001546:Bentonite; D012964:Sodium; C051470:ammonium bromide; D000077215:Clay; C024836:4-nitrophenol