TABLE OF CONTENTS Research into condensation and growth of materials from a vapor has been occurring since the early 1900's but only until the early 1960's has it been formulated in a more concise way. Starting with methods previously applied to atmospheric aerosol condensation Sutugin and Fuchs were able to apply the classical theory to get a first glimpse at the import that the competing processes of coalescence and aggregation play. The work done in the 1990's by Flagan and co-workers and Windeler and co-workers has greatly improved the understanding and application of aerosol condensation theory. With the process of initial nucleation of nanocrystal nuclei unknown, they were still able to formulate a theory that incorporates Brownian collision, aggregation and coalescence growth through surface area minimization and solid state diffusion and agglomerate versus single particle formation.
The factors found to be important to nanocrystal growth from a precursor aerosol were the collision and coalescence times. The collision time gives that time needed for the volume of an agglomerate to double and is highly dependent upon the density of material vapor, the volume of an agglomerate the primary particle diameter and volume loading. The characteristic coalescence time is that needed for an agglomerate of two primary particles to completely coalesce into one spherical nanoparticle. It is highly dependent upon the temperature. Coalescence-limited growth occurs when temperatures fall below approximately 80% of the bulk material's melting point and high volume loading of precursor material such that coalescence of agglomerate particles cannot occur rapidly...
