HOMOGENEOUS NUCLEATION IN SUPERSATURATED VAPOR CONTAINING FOREIGN SEED AEROSOL

The formation of aerosol particles by homogeneous nucleation in a supersaturated vapor containing seed aerosol has been studied experimentally and theoretically. In the laboratory, a room-temperature gas optionally containing zinc chloride particles is continuously mixed with a high-temperature gas saturated with dibutyl phthalate (DBP) vapor in a previously discussed device for the study of aerosol nucleation known as a particle size magnifier (PSM). A highly supersaturated vapor is rapidly formed in the mixing zone of the PSM, and gas-to-particle conversion ensues. The vapor may be converted to the aerosol phase by condensation onto the preexisting particles or by homogeneous nucleation to form new particles which then serve as condensation sites themselves.