Epoxide-mediated synthesis of germania aerogels in acetic acid

A novel alkoxide-free method for the sol-gel synthesis of germania aerogels is proposed. The method is based on the hydrolysis of GeCl 4 by propylene oxide in concentrated acetic acid which is used as a solvent. The proposed protocol allows one to obtain monolithic amorphous germania aerogels constructed of a three-dimensional network of nanoscale (⁓20 nm) particles and possessing specific surface area of about 80 m 2 /g. The addition of hydrochloric acid to the reaction mixture results in the synthesis of nanocrystalline GeO 2 (hexagonal system) aerogels. The synthesized materials were characterized by X-ray diffraction, IR spectroscopy, scanning electron microscopy and low temperature nitrogen adsorption.