Small angle neutron scattering from D2O–H2O nanodroplets and binary nucleation rates in a supersonic nozzle

Autor:	Judith Wölk, Reinhard Strey, Barbara E. Wyslouzil, Kiril A. Streletzky, Christopher H. Heath
Rok vydání:	2003
Předmět:	Number density Chemistry Scattering Neutron diffraction Nozzle Nucleation Analytical chemistry General Physics and Astronomy Small-angle neutron scattering Molecular physics Light scattering Physics::Atomic and Molecular Clusters Two-phase flow Physical and Theoretical Chemistry
Zdroj:	The Journal of Chemical Physics. 118:5465-5473
ISSN:	1089-7690 0021-9606
DOI:	10.1063/1.1554736
Popis:	Small angle neutron scattering (SANS) experiments were used to characterize binary nanodroplets composed of D2O and H2O. The droplets were formed by expanding dilute mixtures of condensible vapor in a N2 carrier gas through a supersonic nozzle, while maintaining the onset of condensation at a fixed position in the nozzle. It is remarkable, given the small coherent scattering length density of light water, that even the pure H2O aerosol gave a scattering signal above background. The scattering spectra were analyzed assuming a log-normal distribution of droplets. On average, the geometric radius of the nanodroplets rg was rg=13 (±1) nm, the polydispersity ln σr was ln σr=0.19 (±0.07), and the number density N was N=(2±0.2)⋅1011 cm−3. The aerosol volume fractions derived from the SANS measurements are consistent with those derived from the pressure trace experiments, suggesting that the composition of the droplets was close to that of the initial condensible mixture. A quantitative analysis of the scattering...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::57bd00fcdf669120146a20b90a9ddbef https://doi.org/10.1063/1.1554736 Zobrazit plný text záznamu