A single-walled-carbon-nanotube filter for removal of viral and bacterial pathogens

An investigation of a novel, highly permeable, single -walled carbon nanotube (SWNT) filter's use for effective removal of bacterial and viral pathogens from water at low pressures was demonstrated. The filter was developed by using a poly( vinylidine fluoride) (PVDF)-based microporous membrane covered with a thin layer of SWNTs. The experiments result showed that E.coli bacteria are completely retained on the SWNT filter and are effectively inactivated upon contact with the SWNTs. The viruses can also be completely removed by a depth-filtration mechanism, that is, capture by nanotube bundles inside the SWNT layer. The development of SWNT-hybrid filter, where the SWNTs are immobilized on a microporous ceramic filter, would be robust, permitting reuse, as the high thermal resistance of carbon nanotubes and ceramics would allow for simple thermal regeneration of the filter. The SEM images and inactivation test results indicate that the SWNT filter is effective in completely retaining the E.coli cells.