A NOTE ON THE GROWTH OF PRIMARY PARTICLES IN AGGLOMERATE STRUCTURES BY COALESCENCE

Aerosol particles at high concentrations grow by collisions and coales cence. If coalescence is faster, particles remain individual and spher ical, and primary particle growth is determined by the collision rate, When collisions are faster, dendritic agglomerates consisting of a la rge number of primary particles form, Primary particle growth is then determined by the coalescence rate, In this Note a model is given for predicting primary particle growth based on the linear decay law for t he surface area of a coalescing structure, In the collision-limited pr imary particle growth regime, the linear decay law is applied to the c oalescing pairs of particles, In the coalescence-limited regime large agglomerates are present, and the linear decay law is applied to subre gions of the agglomerates. (C) 1996 Academic Press, Inc.