Characterization of aerosol particles released during agitation of unprocessed single walled carbon nanotubes, using aerosol particle mass analysis and transmission electron microscopy.
Maynard-A; Ku-BK; Stolzenburg-MR; McMurry-P
Proceedings of the AAAR 23rd Annual Conference, October 4-8, 2004, Atlanta, Georgia. Mount Laurel, NJ: American Association for Aerosol Research, 2004 Oct; :221
As the commercial production of engineered nanomaterials continues to increase, the health and environmental impact of material exposures and releases needs to be quantified and controlled. Single Walled Carbon Nanotubes (SWCNT) represent a unique nanomaterial that is close to production on a commercially viable scale. The size, shape and chemistry of SWCNTs have raised concerns over their harmfulness if inhaled. Recent studies have indicated that unprocessed SWCNT material formed in the gas phase does not readily aerosolize, although when sufficient mechanical energy is imparted to the material, a bimodal aerosol with modes below 50 nm, and between 100 nm and 1 um is generated (Maynard et al. 2004). However, the unprocessed material is a complex matrix consisting of nanotubes, amorphous carbon and transition metal particles, and the relative balance of each within generated particles may profoundly affect aerosol toxicity. Mobility-based size analysis alone is insufficient to determine the structural nature of particles within specific size ranges. To further characterize particles released following agitation of unprocessed SWCNT produced in the HiPCO (High Pressure Carbon Monoxide) process (Bronikowski et al. 2001), Transmission Electron Microscopy (TEM) and Aerosol Particle Mass analysis (APM) (McMurry et al. 2002) have been used to study individual particle morphology and mass. The APM measures the mass of mobilityclassified particles. Together, the two techniques allow an assessment of particle effective density, and enable the APM data to be interpreted in terms of individual particle components. Particles in the mobility diameter ranges of 20 nm - 30 nm, and 100 nm - 150 nm have been studied. Preliminary results indicate that the aerosol primarily consists of compact carbonaceous particles, and not nanotube-rich material.
Aerosols; Aerosol-particles; Microscopy; Particulates; Morphology; Nanotechnology
Abstract; Conference/Symposia Proceedings
Proceedings of the AAAR 23rd Annual Conference, October 4-8, 2004, Atlanta, Georgia