Comparison of α-Al2O3Synthesized by Sol-Gel Process using AlCl3 andAl(NO3)3as Precursors

Abstract

Present study deals with the synthesis and characterization of Al2O3 using two precursors. In the first method inorganic aluminum chloride (AlCl3)was used whereas in the second method aluminium nitrate(Al(NO3)3), malic acid(C4H6O5) and polyvinylpyrrolidone, PVP ((C6H9NO)n) was used.Owing to the difficulty of synthesis of nanosized α-Al2O3 powder due to grain growth at high temperatures involved during calcinations, Al2O3 was prepared by two different sol gel processes. In the first method AlCl3, ethanol and 28 % NH3was used to form a gelfollowed by calcinations at 1200oC for 2 h.In the second process aluminiumnitrate, malic acid and PVP in the mass ratio of 10:3:1.5 was used to form a gel followed by heating the gel at 60oC for 24 h in an oven and then by heat treating at 1250°C for 2 h to form α-Al2O3. The α-Al2O3 formed wasanalyzed by x-ray diffraction (XRD) and particle size analyzer to characterize the powders in terms of their crystallinity and particle size. Microstructural characterization was performed using SEM and TEM.The thermal stability of particles was analyzed usingDSC/TGA.