Abstract
We use static and dynamic light scattering to determine how the diffusion coefficient of a fractal aggregate in the free molecular regime depends on its morphological properties. Our system is a carbonaceous flame soot aerosol containing fractal aggregates with =1.8. We find that the Epstein equation for the diffusion coefficient holds with an effective mobility radius given by =0.99, where N is the number of monomers per aggregate and a is the monomer radius. This result is quantitatively explained as due to the projectional area of the aggregate which includes monomer-monomer screening.
- Received 14 July 1994
DOI:https://doi.org/10.1103/PhysRevE.50.3397
©1994 American Physical Society