Synthesis of carbon-silica core-shell nanofibers from a dispersion of fluorinated carbon nanofibers in solvated polysiloxane

Carbon-silica core-shell fibers (which unusually consist of carbon nanofibers coated with silica) were synthesized using a two-step process. First, fluorination of carbon nanofibers (CNFs) allows their homogenous dispersion into a polysiloxane matrix. A longlife dispersion of nanofibers in solvated polysiloxane has been prepared. Second, the polysiloxane/fluorinated carbon was thermally treated in air until 700 degrees C. Defluorination and conversion of polysiloxane into silica occur and result in carbon-silica core-shell fibers. The thermal treatment of the polysiloxane/carbon and the resulting silica/carbon-silica core-shell nanostructures were investigated using solid state nuclear magnetic resonance using F-19, C-13 H-1, and Si-29 nuclei, X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopies. (C) 2012 Elsevier Ltd. All rights reserved.