Effect of concentration of Al2(SO4)3•18H2O on the synthesis of nanosized alumina

Nanosized alumina has been prepared by the gelation of the solution containing aluminum sulphate and urea followed by low temperature calcination. The effect of different concentrations on pH and its ultimate effect on gelation were studied. Gel formation occurred in the solutions containing 1:20 salt/urea ratio. Aluminum hydroxide and nanoparticles of alumina were characterized by SEM, DTA and TG. The process describes the formation of aluminum hydroxide Al(OH)(3) and its thermal decomposition to Aluminum hydroxyoxide AlOOH and finally to aluminum oxide Al2O3. Nanoparticles of alumina produced were spherical with average particle size of 200 nm.