Plenarvorträge - DPG-Tagungen

Symposium Functional Nanoparticles Dienstag
Fachsitzungen
– Hauptvorträge –
SYNP 1 Functional Nanoparticles - I
Zeit: Dienstag 09:30–11:15 Raum: H1
Hauptvortrag SYNP 1.1 Di 09:30 H1
Semiconductor Nanocrystals: Science and Applications —
•Moungi Bawendi — Department of Chemistry, Massachusetts
Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139,
USA
Semiconductor nanocrystal quantum dots that are of high crystal quality
and have high fluorescence quantum yields have spurred detailed studies
of their electronic and optical properties. Their color range with size
as a result of quantum confinement has motivated applications in fields
ranging from biology to optical devices. This talk will review the chemistry
of nanocrystal quantum dots, the study of the fluorescence properties
of single nanocrystal dots and the insights that have been obtained,
the incorporation of nanocrystal dots in organic light emitting devices,
the observation of stimulated emission and lasing from nanocrystal dots
under optical pumping and the application of nanocrystal dots in biological
and biomedical imaging.
Hauptvortrag SYNP 1.2 Di 10:15 H1
Nano-Optics with Chemically Functionalized Metal Nanoparticles
— •Jochen Feldmann — Photonics and Optoelectronics
Group, Physics Department and CeNS, Ludwig-Maximilians-Universität
München, Amalienstrasse 54, D-80799 München, Germany
Hybrid systems comprising (bio-)molecules with specific functions and
metal nanoparticles of variable geometry and size offer unique and novel
possibilities in nano-optics and optical bio-sensing. When molecules and
metal nanoparticles approach each other, their mutual interaction leads
to characteristic changes in the fluorescent [1] and light scattering properties
[2]. Time-resolved fluorescence spectroscopy and single particle light
SYNP 2 Functional Nanoparticles - II
scattering techniques are well suited to study such processes in detail.
Potential applications in bio-photonics and medical diagnostics are discussed.
[1] E. Dulkeith, A.C. Morteani, T. Niedereichholz, T.A. Klar, J. Feldmann,
S. Levi, F.C. van Veggel, D.N. Reinhoudt, and M. Möller,
Phys. Rev. Lett. 89, 203002 (2002)
[2] G. Raschke, S. Kowarik, T. Franzl, C. Sönnichsen, T.A. Klar, J. Feldmann,
A. Nichtl, K. Kürzinger, Nano Letters 3, 935 (2003)
Hauptvortrag SYNP 1.3 Di 10:45 H1
Biomedical Applications of Magnetic Nanoparticles —
•Lutz Trahms — Laboratory for Bioelectricity and Biomagnetism,
Physikalisch-Technische Bundesanstalt Berlin, D-10587 Berlin, Germany
Magnetic nanoparticles (MNP) having dimensions ranging from a few
nanometers up to a few hundred nanometers may be employed as smart
in-vivo probes, which develop their activity only after external stimulation.
Taking advantage of their particular interaction with externally
applied homogeneous or inhomogeneous constant or time dependent magnetic
fields, MNP can be utilised for a variety of biomedical applications.
Magnetic drug targeting and MNP-coupled hyperthermia are promising
new therapies, which may improve the prognosis for cancer patients. A
couple of years ago MNP were introduced into radiological diagnostics as
a new contrast agent for magnetic resonance imaging. Yet little attention
has been given to the applicability of SQUIDs for localising and quantifying
the amount of MNP accumulated in human tissue. With their high
sensitivity to the magnetic relaxation of MNP, SQUID relaxometry of
MNP could become another useful diagnostic method, in particular for
monitoring MNP-based therapies.
Zeit: Dienstag 11:30–13:10 Raum: H1
Hauptvortrag SYNP 2.1 Di 11:30 H1
Deposited Nanoparticles: Models for Heterogeneus Catalysts
— •Hans-Joachim Freund — Fritz-Haber-Institut der Max-Planck-
Gesellschaft, Department of Chemical Physics, Faradayweg 4-6, D-14195
Berlin, Germany
In an attempt to model heterogeneous and heterogenized homogeneous
catalysts, well-ordered thin oxide films of alumina and silica have been
prepared onto which metal nanoparticles have been deposited via evaporation
of metal from an oven. By controlling the flux of the metal and
the surface temperature nanoparticle ensembles with a rather narrow size
distribution and well-defined morphology may be grown. These systems
are well suited to be investigated applying surface science tools. We report
on a variety of properties of such systems including the electronic
structure, the adsorption as well as the reactive properties. In particular,
size and morphology dependences are studied, both under ultrahigh vacuum
as well as under ambient conditions. We show that such systems, to
a certain extent, allow us to bridge the gaps between catalysis and surface
science. Sum Frequency generation is employed to study vibrational
spectra of surfaces species under ambient pressures.
Hauptvortrag SYNP 2.2 Di 12:00 H1
Nanoscale Ferroelectrics — •Marin Alexe — Max-Planck Institute
of Microstructure Physics, D-06120 Halle, Germany
Nanotechnology is expected soon to have a big impact on most of our
life. Sustained effort will be necessary to transform the nowadays dreams
into reality, and the only way to do it is to acquire a good knowledge
on phenomena at nanoscale. The science of atoms and molecules, on
one end, and the science of matter from microstructure to larger scale,
on the other, are generally established. The remaining size spectrum,
roughly from 1 nm to 100 nm, represents the nanoscale at which properties
of materials are clearly size dependent and can be engineered or
tailored. Among all materials, functional materials are expected to play
an important role in the establishing of nanotechnology. Moreover, among
nanoscale functional materials ferroelectrics are expected to have a major
involvement in fields such as sensors and actuators, memory devices, and
optics.
The present lecture will give the last achievements in the nanofabrication
of ferroelectric materials with both top-down and bottom-up approaches.
Preparation and characterization of ultrathin films, nano-rods
and -tubes, and nanostructures will be presented. Special emphasis will
be put on nanoscale ferroelectric crystals fabricated by self-pattering and
nano-shell ferroelectric tubes fabricated using template-mediated methods.
Hauptvortrag SYNP 2.3 Di 12:30 H1
Synthesis and Application of Functional Nanomaterials —
•Andreas Gutsch and Peter Ottersbach — Degussa AG,
Creavis Technologies & Innovation, Paul-Baumann-Str.1, D-45764 Marl,
Germany
Nanomaterials and ultra-thin functional coatings of nanoparticles will
determine the utility of many products in the future. Degussa possesses
many years of experience in the manufacture and marketing of fine powders.
Fumed silica is used in particular as a reinforcing filler in silicone
rubber and to control the rheology of coatings and colorants. Industrial
carbon black is used particularly in the tire industry and as a
pigment in printing inks, coatings and plastics. Nanoscale titanium dioxide
and zinc oxide ensure effective ultraviolet-filter formulations. The
nanoscale character of such pigments enables easy processing and combines
high sun protection factors with transparency and nice skin feel-