| AVS 55th International Symposium & Exhibition | |
| Nanometer-scale Science and Technology | Friday Sessions |
| Session NS+NC-FrM |
| Session: | Nanoscale Processes |
| Presenter: | S.J. Tsai, University of Massachusetts Lowell |
| Authors: | S.J. Tsai, University of Massachusetts Lowell E. Ada, University of Massachusetts Lowell J. Isaacs, Northeastern University M. Ellenbecker, University of Massachusetts Lowell |
| Correspondent: | Click to Email |
As part of ongoing efforts for the respiratory protection of researchers in the Center for High Rate Nanomanufacturing, nanoparticle exposure levels in various nanoparticle research laboratories were measured. The exposure assessments studied were associated with the use of nanoparticles during various machines processing and handling solid nanoparticles. Background particle number concentrations and particle size distributions varied significantly among the laboratories. Breathing zone particle number concentrations and particle size distributions were not significantly different from those of background when the process or handling was performed inside a laboratory fume hood or an effective local exhaust hood. However, high workers’ breathing zone particle number concentrations were measured for a few operations that were performed without proper local exhaust ventilation. A TSI Fast Mobility Particle Sizer was used to measure airborne particle concentration from 5 nm to 560 nm in 32 size channels. Air samples were also collected on TEM grids placed on polycarbonate membrane filters and particles were characterized by transmission electron microscopy and scanning electron microscopy. Measurement locations were the room background, the researcher’s breathing zone, and the source location. Airborne particle concentrations measured at breathing zone locations were analyzed to characterize exposure level. Elevated concentrations at the source location compared to the background concentration were found in most laboratories. Typically, nanoparticle agglomerates were formed at particle sizes ranging from nanometer to micrometer. Nanoalumina particles with individual particle size less than 100 nm formed airborne particle agglomerates as small as 200 nm and as large as above a few micrometers. Exposure levels to airborne nanoparticles were affected by the properties of nanoparticles (size, shape, density), humidity and the airflow pattern of the environment. Our study is committed to ensuring that nanoparticle research is carried out in a healthful and environmentally beneficial manner. Complete results will be fully discussed in the presentation.