Bon Ki Ku1, Pramod Kulkarni1. 1. Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Division of Applied Research and Technology (DART), 1090 Tusculum Ave, MS-R3, Cincinnati, Ohio 45226, USA.
Abstract
Airborne engineered nanomaterials such as single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), functionalized MWCNT, graphene, fullerene, silver and gold nanorods were characterized using a tandem system of a differential mobility analyzer and an aerosol particle mass analyzer to obtain their airborne transport properties and understand their relationship to morphological characteristics. These nanomaterials were aerosolized using different generation methods such as electrospray, pneumatic atomization, and dry aerosolization techniques, and their airborne transport properties such as mobility and aerodynamic diameters, mass scaling exponent, dynamic shape factor, and effective density were obtained. Laboratory experiments were conducted to directly measure mobility diameter and mass of the airborne nanomaterials using tandem mobility-mass measurements. Mass scaling exponents, aerodynamic diameters, dynamic shape factors and effective densities of mobility-classified particles were obtained from particle mass and the mobility diameter. Microscopy analysis using Transmission Electron Microscopy (TEM) was performed to obtain morphological descriptors such as envelop diameter, open area, aspect ratio, and projected area diameter. The morphological information from the TEM was compared with measured aerodynamic and mobility diameters of the particles. The results showed that aerodynamic diameter is smaller than mobility diameter below 500 nm by a factor of 2 to 4 for all nanomaterials except silver and gold nanorods. Morphologies of MWCNTs generated by liquid-based method, such as pneumatic atomization, are more compact than those of dry dispersed MWCNTs, indicating that the morphology depends on particle generation method. TEM analysis showed that projected area diameter of MWCNTs appears to be in reasonable agreement with mobility diameter in the size range from 100 - 400 nm. Principal component analysis of the obtained airborne particle properties also showed that the mobility diameter-based effective density and aerodynamic diameter are eigenvectors and can be used to represent key transport properties of interest.
Airborne engineered nanomaterials such as single-walled carbon nanotubpan class="Chemical">es (SWCNTs), multi-walled carbon nanotubes (MWCNTs), functionalized MWCNT, graphene, fullerene, silver and gold nanorods were characterized using a tandem system of a differential mobility analyzer and an aerosol particle mass analyzer to obtain their airborne transport properties and understand their relationship to morphological characteristics. These nanomaterials were aerosolized using different generation methods such as electrospray, pneumatic atomization, and dry aerosolization techniques, and their airborne transport properties such as mobility and aerodynamic diameters, mass scaling exponent, dynamic shape factor, and effective density were obtained. Laboratory experiments were conducted to directly measure mobility diameter and mass of the airborne nanomaterials using tandem mobility-mass measurements. Mass scaling exponents, aerodynamic diameters, dynamic shape factors and effective densities of mobility-classified particles were obtained from particle mass and the mobility diameter. Microscopy analysis using Transmission Electron Microscopy (TEM) was performed to obtain morphological descriptors such as envelop diameter, open area, aspect ratio, and projected area diameter. The morphological information from the TEM was compared with measured aerodynamic and mobility diameters of the particles. The results showed that aerodynamic diameter is smaller than mobility diameter below 500 nm by a factor of 2 to 4 for all nanomaterials except silver and gold nanorods. Morphologies of MWCNTs generated by liquid-based method, such as pneumatic atomization, are more compact than those of dry dispersed MWCNTs, indicating that the morphology depends on particle generation method. TEM analysis showed that projected area diameter of MWCNTs appears to be in reasonable agreement with mobility diameter in the size range from 100 - 400 nm. Principal component analysis of the obtained airborne particle properties also showed that the mobility diameter-based effective density and aerodynamic diameter are eigenvectors and can be used to represent key transport properties of interest.
Entities:
Keywords:
aerosolized nanomaterials; morphological descriptors; principal component analysis; transport properties
Authors: Paul A Baron; Gregory J Deye; Bean T Chen; Diane E Schwegler-Berry; Anna A Shvedova; Vincent Castranova Journal: Inhal Toxicol Date: 2008-06 Impact factor: 2.724
Authors: Anna A Shvedova; Elena R Kisin; Robert Mercer; Ashley R Murray; Victor J Johnson; Alla I Potapovich; Yulia Y Tyurina; Olga Gorelik; Sevaram Arepalli; Diane Schwegler-Berry; Ann F Hubbs; James Antonini; Douglas E Evans; Bon-Ki Ku; Dawn Ramsey; Andrew Maynard; Valerian E Kagan; Vincent Castranova; Paul Baron Journal: Am J Physiol Lung Cell Mol Physiol Date: 2005-06-10 Impact factor: 5.464
Authors: Linda M Sargent; Dale W Porter; Lauren M Staska; Ann F Hubbs; David T Lowry; Lori Battelli; Katelyn J Siegrist; Michael L Kashon; Robert R Mercer; Alison K Bauer; Bean T Chen; Jeffrey L Salisbury; David Frazer; Walter McKinney; Michael Andrew; Shuji Tsuruoka; Morinobu Endo; Kara L Fluharty; Vince Castranova; Steven H Reynolds Journal: Part Fibre Toxicol Date: 2014-01-09 Impact factor: 9.400
Authors: Robert R Mercer; James F Scabilloni; Ann F Hubbs; Lori A Battelli; Walter McKinney; Sherri Friend; Michael G Wolfarth; Michael Andrew; Vincent Castranova; Dale W Porter Journal: Part Fibre Toxicol Date: 2013-07-30 Impact factor: 9.400