CONSTRUCTION AND TEST OF LAMINAR-FLOW DIFFUSION CHAMBER - HOMOGENEOUSNUCLEATION OF DBP AND N-HEXANOL

A laminar flow diffusion chamber was constructed for nucleation studie s. The performance of the chamber was tested by investigating the homo geneous nucleation of DBP and n-hexanol vapours. The observed experime ntal nucleation rates varied from 10(2) to 10(8) s-1 cm-3. The experim ental nucleation rates for DBP were observed to be from 3 to 5 orders of magnitude higher than the nucleation rates predicted by the classic al nucleation theory. The experimental results were compared with the self-consistent theory by Girschick, S., Chiu, C.-P. and McMurry, P. ( IM) Time-dependent aerosol models and homogeneous nucleation rates. Ae rosol Sci. Technol. 13, 465 and with the Dillmann-Meier nucleation the ory. The experimental nucleation rates were also compared with other e xperimental studies. The results of the nucleation rate of DBP agree q uite well with the earlier experimental results. For n-hexanol the exp erimental nucleation rates are not as reliable as for DBP due to diffe rent losses. However, the experimental nucleation rates of n-hexanol a gree well with the classical theory and are several orders of magnitud e smaller than the earlier experimental results.