Publication Date:
2014-01-16
Description:
We study the unary and binary nucleation and growth of nonane–D 2 O nanodroplets in a supersonic nozzle. Fourier Transform Infrared spectroscopy measurements provide the overall composition of the droplets and Small Angle X-ray Scattering experiments measure the size and number density of the droplets. The unary nucleation rates J max of nonane, 9.4 × 10 15 〈 J max /cm −3 s −1 〈 2.0 × 10 16 , and those of D 2 O, 2.4 × 10 17 〈 J max /cm −3 s −1 〈 4.1 × 10 17 , measured here agree well with previous results. In most of the binary condensation experiments new particle formation is dominated by D 2 O, but the observed nucleation rates are decreased by up to a factor of 6 relative to the rates measured for pure D 2 O, an effect that can be partly explained by non-isothermal nucleation theory. The subsequent condensation of D 2 O is inhibited both by the increased temperature of the binary droplets relative to the pure D 2 O droplets, and because the binary droplet surface is expected to be comprised largely of nonane. For the one case where nonane appears to initiate condensation, we find that the nucleation rate is about 50% higher than that observed for pure nonane at comparable p v0 , consistent with significant particle formation driven by D 2 O.
Print ISSN:
0021-9606
Electronic ISSN:
1089-7690
Topics:
Chemistry and Pharmacology
,
Physics
