Study on Au nanoparticles, TiO2 nanoclusters, and SiO2 nanoshells coated multi-wall carbon nanotubes/silica gel-glass

Abstract

Multi-wall carbon nanotubes (MWCNTs) coated with crystalline Au nanoparticles, TiO2 nanoclusters, and amorphous SiO2 nanoshells, to represent conductors, semiconductors, and insulators, respectively, were embedded in transparent silica gel-glass. The coated MWCNT/silica gel-glasses were prepared by the sol–gel technique. Scanning electron microscopy (SEM), X-ray diffraction (XRD), UV/Vis spectroscopy, Fourier Transform Infrared (FT-IR) spectroscopy and pore structure measurements were used to investigate the morphology, structure, and texture properties of the coated MWCNT/silica gel-glasses. The hardness and elastic modulus of the silica gel-glasses were characterized using a Nanoindenter and found to depend on the coating materials. Coating the MWCNTs with crystalline Au nanoparticles, TiO2 nanoclusters, and amorphous SiO2 nanoshells leads to an increase in the hardness and elastic modulus, despite the higher specific surface area and pore volume of the coated MWCNT/silica gel-glasses. Consequently, we can conclude that the mechanical properties of coated MWCNT/silica gel-glass might be greatly dependent on the guest MWCNTs rather than the silica gel matrix.