| Nanoparticle aggregates such as carbon spherules, fullerenes consisting of a mixture of aggregates of crystalline graphite nanoparticle, and aggregates of different sizes of multiwall carbon nanotubes and other nanopolyhedra, were collected by thermophoretic precipitation from different combustion sources, and observed by transmission electron microscopy. The combustion-fuel sources used in this research studies were from: natural gas-air, propane air kitchen stove top flame exhausts and natural gas-air water heater roof-top exhausts. The carbon nanotubes structures and end cap variations as well as fullerenes structures were observed to be the same as carbon nanotubes especially, multi-wall carbon nanotubes, produced by arc-evaporation. Nanoparticle aggregation, or the occurrence of carbon nanotubes, arise as aggregates with sizes ranging from 0.5 mum to 1.5 mum. |
