Covalent grafting of ethylene glycol into the Zn-Al-CO3 layered double hydroxide

Zn-Al-CO3 layered double hydroxide was synthesized at room temperature using a procedure reported elsewhere. After characterization, 0.5 g of the Zn-Al-CO3 layered compound was reacted under air with 15 cm(3) of ethylene glycol at 80 degrees C for a period of 5 days. After washing with acetone and drying at 50 degrees C, the resulting white powder was characterized by X-ray powder diffraction, thermal analysis (simultaneous TG/DSC), elemental analysis (C, H, N, Al, and Zn content), and FTIR spectroscopy. All of the experimental data were consistent with the bidentade grafting of ethylene glycol into the interlayer surface of the Al-Zn double hydroxide. The stoichiometry obtained [Zn0.66Al0.34(OCH2CH2O)](OH)(0.34).0.4H2O] showed that all of the surface hydroxide groups were replaced by ethylene glycol through Al-(Zn)-O-C bonds. Carbonate could not be detected by FTIR, proving that OH- was probably the actual intercalated counteranion. (C) 2000 Academic Press.