In the present work, we report an alternative way to prepare inorganic particles of alumina by sol-gel, starting with a metal alkoxide (aluminum butoxide) with controlled pore sizes to obtain a maximum amount of air hollows occluded inside the particle to produce a favorable change in the effective refraction index of the clusters. Furthermore, we characterized the texture and fractal nature of the synthesized materials by means of transmission electron microscopy, thermodynamic analysis of adsorption-desorption isotherms, and small-angle X-ray scattering. The results of this study give a deeper insight into the mechanisms of gel formation.