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ID 114004
Author
Setoura, Kenji Osaka University
Strasser, Michael University of Tokushima
Uwada, Takayuki Josai University
Miyasaka, Hiroshi Osaka University
Content Type
Journal Article
Description
Pump-probe transient extinction spectroscopy was applied to analyze 355-nm picosecond laser heating-induced phenomena of 60-nm-diameter aqueous gold nanoparticles (AuNPs) under a high pressure of 60 MPa. Kinetic spectroscopy revealed that a supercritical layer surrounding the AuNP nucleated with a lifetime of approximately 1 ns in its dynamic expansion and decay behavior for a fluence of 19.6 mJ cm−2. Moreover, we observed in the post-mortem transmission electron micrographs a number of fragments, a small percentage of size-reduced cores, and erupted particles, among the intact particles after 60 shots, suggesting that evaporation occurs under laser illumination. The particle temperature calculation indicated that evaporation begins with a liquid droplet AuNP surrounded by a supercritical layer at temperatures below the boiling point of gold. By applying high pressure, we are able to obtain a clear picture of the evaporation event, which was not possible at ambient pressure because the forming bubble caused particle temperatures to rise uncontrollably. In this study, we shed light on the critical role of the supercritical layer formed around the AuNP under high pressure during laser-induced evaporation.
Description Alternative
Pulsed-laser illumination of aqueous gold colloids under high pressure enables the evaporation from liquid droplets surrounded by supercritical water layer.
Journal Title
Physical Chemistry Chemical Physics
ISSN
14639076
14639084
NCID
AA11301773
AA11723355
Publisher
The Royal Society of Chemistry
Volume
18
Issue
6
Start Page
4994
End Page
5004
Published Date
2016-01-14
EDB ID
DOI (Published Version)
URL ( Publisher's Version )
FullText File
language
eng
TextVersion
Author
departments
Science and Technology