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Page 62
November 13-14, 2017 Paris, France
5th International Conference on
PLASMA CHEMISTRY AND
PLASMA PROCESSING
Journal of Biotechnology and Phytochemistry
Volume 1, Issue 2 Plasma Chemistry 2017
Pulsed laser ablation in liquids: what can we
learn from the bubble diagnoses?
D Amans1,2
1Institut Lumière Matière-Université Lyon 1-CNRS, France
2Université de Lyon, France
Pulsed laser ablation in liquids (PLAL) is a versatile
technological approach to producing nanoparticle colloids
with ligand-free or functionalized surfaces. Therefore, PLAL
has aroused a lot of commercial interests recently. Despite this
widespread use, the underlying mechanisms of PLAL are not
fully understood yet. In a first step, a liquid confined plasma
is created by the laser ablation. Then, numerous authors
reported the formation of an expanding bubble from which
nanoparticles are released. According to small angle x-ray
scattering (SAXS) measurements and laser-light scattering
measurements the bubble cavity should support nucleation
and growth of nanoparticles. However, two fundamental
features remain largely unknown: the chemical composition
and the thermodynamic properties within the bubble. Using
time-resolved plasma spectroscopy and ultrafast imaging, we
address both issues. We then develop theoretical approaches.
From a Rayleigh-Plesset based model, we demonstrated
that (i) inertial forces drive the bubble dynamics, (ii)
vapor evolution is adiabatic, and (iii) the bubble is mainly
composed of evaporated solvent. Moreover, we present a fully
microscopic approach based on a first-principle study, and
propose a scenario of composition gas evolution leading to
the first seeds. This approach is illustrated in the framework
of alumina. These results will be discussed in the framework
of the state of the art (diagnoses and models).
J Biot Phyt 2017