Characterization and evaluation of nanoparticle release during the synthesis of single-walled and multiwalled carbon nanotubes by chemical vapor deposition.

Airborne nanoparticles released during the synthesis of single-walled and multi-walled carbon nanotubes were measured and characterized. This study reported the field measurements during the development of carbon nanotube production. Monitoring data were taken and the sampling methods to characterize aerosol release were developed along with the modification of carbon nanotube production in a time period from 2006 to 2009. Particle number concentrations for diameters from 5 nm to 20 microm were measured using the fast mobility particle sizer and the aerodynamic particle sizer; the particles released from the furnace were found to be less than 500 nm in diameter. The morphology and elemental composition of the released nanoparticles were characterized by scanning and transmission electron microscopy and energy dispersive spectroscopy. Different operating conditions of multi-walled carbon nanotubes (MWCNT) production were studied to evaluate their effects on the number and morphology of aerosol particles, and the number of particles released. Carbon nanotube filaments and carbon particles in clusters were found among the released aerosol particles during production of multiwalled carbon nanotubes.