Collection and characterization of airborne nanoparticulates

This paper describes the use of a thermal precipitation device to collect representative, airborne nanoparticulates on transmission electron microscope (TEM) grid supports and their characterization using a bright field (BF)–dark field (DF)–selected area electron diffraction (SAED)–energy dispersive spectrometry (EDS) analysis protocol. Two airborne nanoparticulate regimes are illustrated and compared: (1) general nanoparticulates, composed of nanocrystalline aggregates containing from 2 to >1000 individual particles, ranging in size from approximately 1 to 100 nm and (2) complex, branched clusters of amorphous, carbonaceous spherules (containing from 50 to >1000 spherules, which range in size from 10 to 40 nm in diameter) and carbon nanocrystal aggregates containing nanotubes and other polyhedra. Commercial nanoparticulate aggregates of TiO2 and Si3N4 are also observed in the context of characterization standards and the nanotechnology potential for contributing to atmospheric pollutants.