Transcript Physical-Chemical Properties Controlling the Environmental Fate of Nanoparticles

Department of Chemistry
Seminar Announcement
Date/Time/Venue
Title/Speaker
14 Feb (Mon)
11am – 12nn
Physical-Chemical Properties
Controlling the Environmental Fate of
Nanoparticles
@ S8 Level 3
Executive
Classroom
Professor Andrew M Shaw
University of Exeter, UK
Host : Assoc Prof Thorsten Wohland
About the Speaker
Professor Andrew M Shaw received his MA in Natural Sciences from
University of Cambridge and PhD in Physical Chemistry from University
of Southampton in 1992. He carried out his postdoctoral research in
Stanford University in 1999. He joined the faculty at the University of
Exeter in 2001 and is currently an Associate Professor of Physical
Chemistry. He is also the Founder and Director of Research of
EvanesCo Ltd. His research uses the principles of physical chemistry
to make measurements on systems in Chemical Biology. His research
group is currently developing a screening technology that will allow the concentrations of
molecules in blood to be measured that may act as biomarkers of disease and extend the
field of differential diagnosis. His research concentrates on the fundamental the
quantitative description of measurements interpreted with a mathematical model. The
research directions have led to the formation of a company to exploit the technology
commercially with application in the petrochemical industry, production quality
monitoring and Homeland Security. Teaching interests in the School are Physical
Chemistry for the Life Sciences, Astrochemistry and Astrobiology and Forensic Science. All
modules explore the quantitative interpretation of physical processes. He has written a
textbook Astrochemistry: From Astronomy to Astrobiology, published by Wiley in 2006.
Abstract
The physico-chemical properties of the nanoparticles ZnO and CeO2 are considered with
respect to their stability and ultimate fate in the environment and subsequent toxicity. The
negatively charged ZnO particles found in Nanosun and Z-cote commercial materials
have good dispersion stabilities in pure water and poor stabilities in salty media. The
empirical half-life of these dispersions and the mechanisms of stabilisation will be
considered including NICCA adsorption isotherms and adsorption kinetics. Results from
evanescent wave cavity ring-down spectroscopy and their quantitative analysis of the
resulting charged interface structure will be presented. The concentration of nanoparticles
in OECD soil samples is assayed using a new photo-radical generation assay and this is
used to determine the effects of nanoparticle dissolution relative to stability. Adsorption of
Zn2+ to OECD clay surfaces is also considered as a time-dependent source of toxic Zn. The
metal and radical stress responses of E. coli are considered as a comparison organismlevel assay of the physical and chemical properties in the nanoparticle toxicity.
All are Welcome