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

A laminar flow diffusion chamber was constructed for nucleation studies. The performance of the chamber was tested by investigating the homogeneous nucleation of DBP and n-hexanol vapours. The observed experimental nucleation rates varied from 10(2) to 10(8) s-1 cm-3. The experimental nucleation rates for DBP were observed to be from 3 to 5 orders of magnitude higher than the nucleation rates predicted by the classical 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. Aerosol Sci. Technol. 13, 465 and with the Dillmann-Meier nucleation theory. The experimental nucleation rates were also compared with other experimental studies. The results of the nucleation rate of DBP agree quite well with the earlier experimental results. For n-hexanol the experimental nucleation rates are not as reliable as for DBP due to different losses. However, the experimental nucleation rates of n-hexanol agree well with the classical theory and are several orders of magnitude smaller than the earlier experimental results.