SYNTHESIS AND CHARACTERIZATION OF THE LAYERED ZIRCONIUM ARSENATE ZR2O3(HASO4)CENTER-DOT-NH(2)O

Layered sodium zirconium arsenate of composition Zr2O3(NaAsO4). 3H(2)O was prepared by the reaction between Zr(OC3H7)(4) and sodium arsenate in alkaline media (pH > 12) under mild hydrothermal conditions (180-2 00 degrees C). Two hydrogen forms of the zirconium arsenate (psi-ZrAs) Zr2O3(HAsO4). 3H(2)O and Zr2O3(HAsO4). H2O, were prepared by acid tre atment of the sodium form. The intercalation of n-alkylamines into the psi-ZrAs from the gas phase was studied. The synthesized materials we re characterized by elemental analysis, thermogravimetric analysis, in frared spectroscopy and powder X-ray diffraction. The data indicate th at the zirconium arsenate is isostructural to psi-Zr2O3)(HPO4). nH(2)O (n = 0.5, 1.5). The new compounds exhibit high hydrolytic stability i n alkaline media. The ion exchange behavior of the psi-Zr2O3(HAsO4). 3 H(2)O towards alkali, alkaline-earth, and some di- and tri-valent meta l cations in different solutions was studied over a wide pH range (2-1 4) by the batch technique. (C) 1998 Elsevier Science Ltd.