Modification of Aluminium Alkoxide with Different Long-Chain Chelating Agent: Hydrolysis and Characterization of the Product

Abstract

An aluminum alkoxide, [Al(OCH 2 CH 2 OCH 2 CH 3 ) 3 ] (O 1 ), was synthesized by alcohol exchange method and after characterization by 27 Al NMR, 1 H NMR, infrared spectroscopies and mass spectrometry was used as a precursor for the preparation of high quality c-alumina. c-aluminas also were prepared from [Al(OCH 2 CH 2 OCH 2 CH 2 OCH 3 ) 3 ] (O 2 ) and [Al(OCH 2 CH(CH 3 )CH 3 ) 3 ] (O 3 ) in an identical hydrolysis condition and their textural parameters compared to that of prepared from O 1 . The gels obtained from hydrolysis of aluminum alkoxides by sol-gel processing were characterized by X-ray powder diffraction, thermal analysis, scanning electron microscopy (SEM), and nitrogen adsorption-desorption analysis. The X-ray diffraction patterns showed the materials obtained from hydrolysis of O 1 , O 2 and O 3 are pseudoboehmite and converts to c-alumina by calcinations at 800°C. The alumina obtained from hydrolysis of O 3 showed higher surface area (S BET ), slightly above 200 m 2 /g and lower particle size, about 40-50 nm, than aluminas prepared from the hydrolysis of O 1 and O 2 . SEM showed that morphology of alumina obtained from O 2 is different to a great extent than the ones obtained from other precursors. Moreover, a transparent monolith gel has been prepared from O 1 .