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KAISERSLAUTERN
Fachbereich Physik
EINLADUNG
ZU\A PHYSI KALISCHEN KOLLOQU I UM
AM MONTAG,25. Juni 2012 UM 17.15 UHR
HS 46t270
ES SPRICHT:
Prof. Geoffrey A. Ozin
Materials Chemistry and Nanochemistry Research Group, Center for lnorganic
and Polymeric Nanomaterials, Chemistry Department, University of Toronto
Thema:
" Green Nanochemistry "
Nanomaterials prepared by nanochemistry approaches are polydispersions with a characteristic nanoparticle size distribution.
This means that nanoparticle propeties measured and reported
to date, whether chemical, physical or biological, refer to an
ensemble average. This makes the quantitative evaluation of
their toxicity, whether in vivo or in vitro, precarious at best as
one never can be absolutely sure whether it is a specific size,
shape or surface property of a nanopartlcle or a certain group of
nanoparticles or every nanoparticle in an ensemble that is responsible for a positive toxicity test result and may therefore
pose a health and safety hazard to researchers, manufacturers
and consumers. The same uncertainty applies to the behavior,
fate, bioavailabilty and effects of nanoparticles that escape into
the environment.
Currently many Fortune 500 companies and about 1500 spin-off
companies around the world are involved in nano R&D and there
aTe now about 600 nano-based products on the market. It is
ironic that while nanoparticles are gainfully exploited
in
nanoscience and nanotechnology and celebrated for their exquisite size, shape and surface tunable properties, it is precisely these
attributes that are potentially problematic in health and safety matters when trying to quantify the toxicity of a poly-dispersion of
nanopaticles where it is impossible to decide whether it is the size, shape or surface of all, some, one or none of these nanoparticles that we have to be concerned about.
With this in mind it makes sense to intensify the global research effort of the nanochemistry community on the synthesis and study
of nanoparticles that are purportedly "green", The newest collection of "green" nanoparticles to have caught my attention recently
and which seem to be most promising candidates in this context are based on C, Si, Ge, Bi whose appealing energy storage, optical, optoelectronic, photonic and biomedical attributes are gaining much attention.
In this lecture I will describe our recent work on the synthesis and size separation of poly-dispersions of colloidally stable silicon
nanocrystals into mono-dispersions, the measurement of representative size dependent properties, and steps towards their integration into optoelectronic and biomedical devices. So when contemplating growing your nano materials garden for pleasure or
profit, think "green"l
Der Gast wird betreut von Herrn Prof. von Freymann.
GASTE SIND HERZLICH WILLKOMMEN.
KAFFEEAUSSCHANK AB 17.00 UHR
Kaiserslautern, den 18.06.2012
DIE DOZENTEN DES FACHBEREICHS