Nanoporous g-Al2O3 samples were synthesized via a sol-gel technique, introducing changes in the Yoldas´ method. The aim of the work was to achieve an effective control of the nanostructure properties and morphology of the final g-Al2O3. The influence of the reagent temperature during the hydrolysis was evaluated in case of water at 5 ºC and 98 ºC, and alkoxide at -18 ºC and room temperature. Sol-gel transitions were performed at 120 ºC and room temperature. All g-Al2O3 samples were characterized by X-ray diffraction, nitrogen adsorption and thermal analysis. Our results showed that temperature of both water and alkoxide has not much influence on the nanostructure of the final g-Al2O3, thus giving a structure very similar to that of samples obtained by the reference method as long as the reaction temperature above 75 ºC is reached soon enough. XRD characterization showed diffraction patterns corresponding to g-Al2O3 for all samples. Also BET specific area values (253-280 m2/g) were similar to those obtained by Yoldas’s original method. The temperature of the sol-gel transition does not affect the resulting sample structure, and crystalline boehmite particles were identified in all dried gels. We analyzed the reproducibility of the samples’ structure by preparing different samples under identical conditions; we found that performing the sol-gel transition at 120 ºC favors the production of more reproducible samples and also reduces significantly the time of the sol-gel reaction.
 M.A. Dimitrijewits de Albani and C.P. Arciprete, “A study of pore size distribution and mean pore size on unsupported gamma-alumina membranes prepared by modifications introduced in the alkoxide hydrolysis step”. J. Mem. Sci., vol 69, pp. 21-28. 1992.
 D. Quatrini, D. Serrano, S. Perez Catán, “Modifications in the microstructure of alumina porous materials by hydrothermal treatment”, Gra. Mat., vol. 3, pp. 125-139. 2001.
 M. Akia, S. M. Alavi, M. Rezaei, Z. F. Yan. “Optimizing the sol-gel parameters on the synthesis of mesostructurenanocrystallineγ-Al2O3”. Mic. Mes. Mat., vol. 122, pp.72-78. 2009.
 B.E. Yoldas, “Alumina Sol Preparation from Alkoxides”. Cer. Bul., vol. 54, no. 3, pp. 289-290. 1975.
 B.E. Yoldas, “Alumina gels that from porous transparent Al2O3”. J. Mat. Sci., vol. 10, pp. 1856-1860. 1975.
 B.E.Yoldas, “Hydrolysis of Aluminium Alkoxides and Bayerite Conversion”. J. Appl. Chem. Bio., vol. 23, pp. 803-809. 1973.
 B.E. Yoldas, “Effect of Variations in Polymerized Oxides on Sintering and Crystalline Transformations”, J. Ame. Cer. Soc., vol. 65, no. 8, pp.387-393. 1982.
 J.Brinker and G.W. Scherer, “Sol-Gel Science. The Physics and Chemistry of Sol-Gel Processing”. USA, CA: Academic Press, INC., 1990.