Small angle x-ray scattering measurements probe water nanodroplet evolution under highly non-equilibrium conditions.
Our in situ small angle X-ray scattering (SAXS) measurements yield an unprecedented and detailed view of rapidly evolving H{sub 2}O nanodroplets formed in supersonic nozzles. The SAXS experiments produce spectra in a few seconds that are comparable to small angle neutron scattering (SANS) spectra requiring several hours of integration time and the use of deuterated compounds. These measurements now make it possible to quantitatively determine the maximum nucleation and growth rates of small droplets formed under conditions that are far from equilibrium. Particle growth is directly followed from about 10 {micro}s to 100 {micro}s after particle formation with growth rates of 0.2 to 0.02 nm {micro}s{sup -1}. The peak H{sub 2}O nucleation rates lie between 10{sup 17} and 10{sup 18} cm{sup -3} s{sup -1}.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); National Science Foundation (NSF); Donors of Petroleum Research Fund
- DOE Contract Number:
- DE-AC02-06CH11357
- OSTI ID:
- 939328
- Report Number(s):
- ANL/XSD/JA-60197; TRN: US0806753
- Journal Information:
- Phys. Chem. Chem. Phys., Vol. 9, Issue 39 ; 2007; ISSN 1463-9076
- Country of Publication:
- United States
- Language:
- ENGLISH
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