Modeling the Mass Transfer of Semivolatile Organics in Combustion Aerosols

A radial diffusion model was developed to describe the mass transfer of semivolatile organics into and of combustion aerosols. The model combustion aerosol of a solid carbon core that is surrounded by a , liquid-like, organic layer. Diffusion takes place within the organic layer and is controlled by mass at the particle surface. Modeling of semi volatiles the tuning of two separate parameters: a diffusion (D) and a surface mass transfer coefficient (α). testing of the model on the uptake of pyrene by diesel exhaust aerosol at a temperature 25 °C suggests that diffusion coefficients for are of the order of 10^(-15) cm^2/s and that surface mass transfer coefficients for pyrene are of the order of 10^(-10) cm/s.