MORPHOLOGICAL AND DYNAMIC CHARACTERIZATION OF PB FUME PARTICLES UNDERGOING BROWNIAN COAGULATION

Morphological changes of Pb fume particles undergoing Brownian coagulation in a flowing system were studied using computer image processing of two-dimensional electron micrographs to measure radii of gyration and perimeters. From these two parameters; (1) fractal dimensions were calculated considering the aggregates as multifractal; changes in fractal dimension were related to the degree of agglomeration; (2) volume equivalent diameters were calculated based on a new relationship between volume and projected area for fractal aggregates, presented in Appendix A. The validity of this equation was confirmed for aggregates composed of small numbers of primary particles (n < 30); and (3) dynamic shape factors were calculated and comparison was made with a new relationship between shape factor and volume equivalent diameter presented in Appendix B. © 1990.