engleski

Microstructural analysis of sol-gel-derived boehmite nanoparticles

Sol-gel processing from Al-alkoxides is important synthesis route in the preparation of nanosize Al-oxide particles. Many researches investigated the conditions of slow hydrolysis of Al-oxides (group name for Al-hydroxides, -oxyhydroxides and – oxides). In the present work we focused on the synthesis of nanosize boehmite particles using abrupt hydrolysis of Al-sec-butoxide and the influence of the experimental conditions on the properties of the particles synthesized. The obtained results show that processing parameters (pH, temperature and time of the synthesis) significantly influence structural and microstructural properties of the obtained boehmite products. The results of FE-SEM analysis indicate significant difference in the morphology of the obtained boehmites (plates, needles, granules). The results of line broadening analysis of the powder diffraction patterns (Le Bail method - program GSAS) indicate presence of very small anisotropic crystal domains (from 1 to 7 nm in direction 010 and from 2 to 16 nm in direction perpendicular to 010). In all cases parameters that contribute to the strain broadening of the diffraction lines decrease to nearly zero, which indicate that the obtained boehmites are almost strain free.

Al-oxides; powder diffraction; FE-SEM; sol-gel; line broadening analysis

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