Generation and characterization of ultrafine chain aggregate aerosols

Continuously stable well-characterized chain aggregate aerosol sources generated from a flame aerosol generator are described. To characterize the length of the chain aggregate a new image processing software was developed to measure the length distribution of aggregates. This program measures the path length of the aggregate that has been skeletonized into one pixel in width while maintaining its length and shape. In order to generate monodisperse chain aggregate sources a differential mobility analyzer was used to classify aggregates according to electrical mobility. A series of experiments were conducted to generate singly charged monodisperse chain aggregate aerosol sources. The operational range of the system for generation of monodisperse chain aggregates is described. Single-mode chain aggregates with a geometric mean particle length between 1.50 and 3.20 μm and a length standard deviation around 1.3 were generated.