Morphological and chemical/physical characterization of Fe-doped synthetic chrysotile nanotubes

In the field of thin-layered-structured inorganic nanotubes, morphological, structural, and chemical/physical modifications induced in synthetic stoichiometric chrysotile nanotubes have been evaluated as a function of the extent of Fe doping, Fe doped synthetic chrysotile nanocrystals have been obtained in the range from 0.29 wt.-% up to 1.37 wt.-% Fe. A partial Fe replacement for Si and Mg has been observed through the modification of Fourier-transform infrared (FTIR) absorption bands. FTIR spectroscopic, X-ray diffraction,and thermogravimetric analyses provide evidence for FE inclusion into the chrysotile crystal structure, in both octahedral and tetrahedral sites, which induces a flattening of the curved brucite-like layers in the stoichiometric chrysotile. Further characterization by morphological analysis (scanning electron microscopy, transmission electron microscopy, and atomic force microscopy) has revealed the effect of Fe doping on the aggregation of chrysotile nanotubes. The results appear interesting in light of the proposed possibilities of synthetic chrysotile fibers to represent an alternative to carbon nanotubes for innovative technological applications.