Since the discovery of carbon nanotubes (NTs), there has been great interest in the synthesis and characterization of similar shaped structures like inorganic nanotubes, nanorods, or nanowires. Imogolites (Al₂SiO₃(OH)₄) are natural aluminosilicate single wall nanotubes. To date, only Ge-Al imogolite analogues have been successfully synthesized 100 times more  concentrated than Si-Al imogolites.

The growth mechanisms of imogolite-like aluminogermanate nanotubes were examined using a combination of local- (XAS at the Ge-Kedge and 27Al NMR) and semilocal scale techniques (in situ SAXS). A model is proposed for the precursors of the nanotubular structure and consist in rooftile-shaped particles, up to 5 nm in size, with ca. 26% of Ge vacancies and varying curvatures. These precursors assemble to form short nanotubes/nanorings observed during the aging process. The final products are most likely obtained by an edge-edge assembly of these short nanotube segments.

Two structures are revealed by SAXS: at 0.25M of Al the Al-Ge imogolite are double-walled NTs whereas at 0.5 M single-walled NTs are obtained.

First tests to reveal cyto  and genotoxicity on various vertebrates cells (human fibroblasts and CHO-K1) are interesting. They show a genotoxicity for concentrations from 8 10^-5 g/L and effects decreasing from proto-imogolite to long tubes