Evolution of an Aerosol Size Distribution During Gas-to-Particle Conversion

6 EVOLUTION OF AN AEROSOL SIZE DISTRIBUTION DURING GAS-TO-PARTICLE CONVERSION 

Atmospheric aerosols evolve in size by coagulation and gas-to-particle conversion. To understand the evolution of a size spectrum it is necessary to understand the influences of these two phenomena. Aerosols in the size range 0.01 to 1.0 /im diameter grow principally by gas-to-particle conversion, the process by which vapor molecules diffuse to the surface of a particle and subsequently are incorporated into the particle. 

The main objective of this section is to theoretically compare aerosol size spectra evolving by the mechanisms of diffusion-, surface reaction-, and volume reaction-controlled growth. The results will provide a basis for the interpretation of atmospheric and laboratory aerosol size spectra with respect to the original growth mechanisms. 

Let us consider the continuous condensation equation, (12.8), written in terms of particle mass m as the size variable, so that n(m, t) is the size distribution function based on particle mass, and / ,(m, t) is the rate of change of a mass of a particle of mass m due to condensation  

The study of the evolution of an aerosol distribution from an initial shape 

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