Scanning electron microscopy images of large bundles of SWNTs. Low and high magnification SEM images of small-bundled SWNTs networks grown from 0.4 wt% Co-acetate ethanol solution. (a) Network of bundled SWNTs on 50 nm silica nanoparticles. (b) High magnification image of (a). SWNTs bundles are grown from silica nanoparticles and make connection with each other. (c) SEM image of SWNT bundles on 200 nm silica nanoparticles. (d) High magnification image of (c). More and bigger bundles are grown from silica particles and also make more connections with other bundles or SWNTs.