PHOTOCHEMICAL AEROSOL FORMATION OF HALOIDBENZENES - COMPARISON BETWEEN THEORY AND EXPERIMENT

Experimental data of haloidbenzene (PhHal) photonucleation by Dubtsov et al. (1992 J. Aerosol Sci. 23, 181) are reevaluated using improved c omputer simulations of number concentration and size distribution duri ng photonucleation based on solving the Smoluchowski coagulation equat ions. A new two-step algorithm for their solution was used. A new appr oach to determine monomer formation rate and a minimal detectable clus ter size is proposed. Measured number concentrations vs irradiation ti me and size distributions (2-100 nm) are in reasonable agreement with the model results. The experimentally observed bimodal particle size d istribution with irradiation time-dependent concentration ratio betwee n modes is reproduced in the model. The model also qualitatively corre ctly describes the temporal evolution of the size distribution. Remain ing quantitative discrepancies are discussed.