engleski

COMBUSTION SYNTHESIS OF AL2O3 WITH ASPARAGINE AS FUEL

Most approaches to porous materials syntheses require the use of templates for gaining the requested morphology and thus are complex, time consuming and costly. Due to its effectiveness and low cost, combustion synthesis is used as an alternative method of porous materials synthesis. It does not need to use a template because of the formation of gases which create a porous structure while escaping the sample. It can be used for production of nanoparticles and gives a pure, homogeneous oxide powder. Alumina was prepared via combustion synthesis from aluminum nitrate nonahydrate using asparagine as a fuel. Equivalence ratio of fuel and oxidizer, φ, on product properties is investigated. Equivalence ratios used were φ=0, 5 for a fuel lean mixture, φ=1 for a stechiometric sample and φ=1, 5 for a fuel rich sample. Methods of analysis used were X-ray diffraction (XRD), infrared spectroscopy with Fourier transformation (FTIR), scanning electron microscopy (SEM) and N2 adsorption/desorption isotherms. XRD analysis showed that the heat liberated in samples during the course of the synthesis was not high enough to obtain γ-Al2O3 so additional thermal treatment of samples was necessary. DTA analysis showed that in all of the as prepared samples there is considerable quantity of residual organic phase. According to SEM analyses and N2 adsorption/desorption isotherms it was determined that equivalence ration has great influence on microstructure and pore distribution of prepared γ-Al2O3.

combustion synthesis, γ-alumina, asparagine

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