title: Characterization of exposures to nanoscale particles and fibers during solid core drilling of hybrid carbon nanotube advanced composites.
abstract: This work investigated exposures to nanoparticles and nanofibers during solid core drilling of two types of advanced carbon nanotube (CNT)-hybrid composites: (1) reinforced plastic hybrid laminates (alumina fibers and CNT); and (2) graphite-epoxy composites (carbon fibers and CNT). Multiple real-time instruments were used to characterize the size distribution (5.6 nm to 20 microm), number and mass concentration, particle-bound polyaromatic hydrocarbons (b-PAHs), and surface area of airborne particles at the source and breathing zone. Time-integrated samples included grids for electron microscopy characterization of particle morphology and size resolved (2 nm to 20 microm) samples for the quantification of metals. Several new important findings herein include generation of airborne clusters of CNTs not seen during saw-cutting of similar composites, fewer nanofibers and respirable fibers released, similarly high exposures to nanoparticles with less dependence on the composite thickness, and ultrafine (< 5 nm) aerosol originating from thermal degradation of the composite material.
authors.affiliation: Department of Work Environment, University of Massachusetts Lowell, Lowell, MA 01854, USA. Dhimiter_Bello@uml.edu
authors.forename: Dhimiter
authors.initials: D
authors.lastname: Bello
authors.forename: Brian L
authors.initials: BL
authors.lastname: Wardle
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Namiko
authors.initials: N
authors.lastname: Yamamoto
authors.forename: Christopher
authors.initials: C
authors.lastname: Santeufemio
authors.forename: Marilyn
authors.initials: M
authors.lastname: Hallock
authors.forename: M Abbas
authors.initials: MA
authors.lastname: Virji
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis* / Q000737:chemistry; D004391:Dust; D004784:Environmental Monitoring / Q000379:methods; D008854:Microscopy, Electron; D053758:Nanoparticles / Q000032:analysis* / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000032:analysis* / Q000737:chemistry; D016273:Occupational Exposure / Q000032:analysis*; D010316:Particle Size
chemical_list: D000395:Air Pollutants, Occupational; D004391:Dust; D037742:Nanotubes, Carbon