Covalent Grafting of Phenylphosphonate Groups onto the Interlamellar Aluminol Surface of Kaolinite.
Kaolinite (K) was reacted with phenylphosphonic acid (PPA) in a water:acetone (1:1 V/V) solution (molar ratio 1 K:3 PPA), at 95 +/- 5 degreesC for different periods of time. Two different compounds (white powders) were identified but only one was isolated as a single phase and characterized by X-ray diffraction (powder method), thermal analysis (TG-DSC), Fourier-transformed infrared spectroscopy, and chemical analysis. The first compound showed a layer expansion of 7.86 Å and the second, a layer expansion of 9.29 Å, obtained as a decomposition product. Both compounds are consistent with the grafting of the phenylphosphonate group to the layers of kaolinite. The compounds have a formula of Al2Si2O5(OH)(HO3PPh)3.0 . 2H2O, as determined by thermal (water and total organic matter loss) and chemical (C content) analysis, respectively. Copyright 1998 Academic Press.
Guimarães
JL
Department of Chemistry, Federal University of Paraná, Curitiba, PR, CEP 81531-990, Brazil
Peralta-Zamora
P
Wypych
F