US EPA

3580656 

Journal Article 

Measurements of the diffusion-coefficients of ultrathin asbestos fibers 

Gentry, JW; Spurny, KR; Soulen, SA; Schörmann, J 

1988 

Yes 

Journal of Aerosol Science
ISSN: 0021-8502
EISSN: 1879-1964 

19 

7 

1041-1044 

English 

10.1016/0021-8502(88)90096-1 

WOS:A1988R859000065 

A study of the diffusion coefficients of asbestos (1332214) fibers with diameters in the range from 0.03 to 0.08 micrometers in which non continuum effects would be expected, has been carried out using chrysotile (25666971) fibers whose size was determined by electron microscopy. Energy dispersive x-ray analysis and electron diffraction patterns were used to determine fiber composition. The diffusion coefficients were determined through the use of an apparatus in which fiber flow through a breslin type diffusion battery was controlled, with the fraction penetration being measured by transmission electron microscopy. The experimental setup incorporated in this study yielded diffusion coefficients in the range from 6x10(-5) to 1.4x10(-5) centimeters squared per second. These results were greater than what would have been theoretically predicted based upon the mean fiber diameter and aspect ratio, which were 0.061 and 45 micrometers, respectively. It was also determined that, although the diffusion coefficient exhibited a notable dependence on fiber diameter, there was not any documentable trend with increasing aspect ratio. The authors conclude that these results show notable differences between theory and experimental diffusion coefficients. The uncertainty in the measurement derived values was large.