Scanning electron microscopy images of small bundles of SWNTs. Low and high magnification SEM images of small-bundled SWNTs networks grown from 0.2 wt% Co-acetate ethanol solution. (a) Two- or three-dimensional SWNTs bundles networks are grown on 50 nm silica nanoparticles. (b) High magnification SEM image of the same sample shown at (a). Small size bundles of SWNTs are interconnected on silica nanoparticles. (c) SWNTs bundles grown on 200 nm silica nanoparticles. (d) High magnification SEM image of sample on 200 nm silica nanoparticles. The bundle size is slightly bigger than that of image (b).