Performance improvement of micron-sized fibrous metal filters by direct growth of carbon nanotubes

Carbon nanotubes were synthesized directly by thermal chemical vapor deposition onto the surface of micron-sized metallic fibers to improve the filtration performance of a conventional metal filter. Depending on the synthesis conditions, carbon nanotubes grew up to consist of microstructures like bushes surrounding the metal fibers or like webs crossing between the fibers. The carbon nanotubes grown around the fibers collected more particulate pollutants, so that the filtration efficiency increased without significant increase of pressure drop. Especially, the filtration performance was improved when the CNTs formed the microstructures having the morphology such as naps or weeds on the micron-fibers.