Ciclo de Seminarios 2010
2010 6 AGO
Viernes 6 de Agosto
11:00 hs. - Auditorio del nivel +63
Edificio TANDAR
"Modelling structure formation in diblock copolymer materials on patterned surfaces"
Prof. Dr. Marcus Müller
(*)
Institut für Theoretische Physik - Georg-August Universität - Göttingen
RESUMEN:
Diblock copolymers self-assemble into a variety of periodic nano-structures in the bulk. The length
scale is dictated by the molecular extension and ranges from 10 nm to 100nm. The application of
copolymer materials have attracted abiding interest for templating nano-structures in
microelectronics and catalysis. If the copolymer material is in contact with a patterned surface,
the morphology of the diblock copolymer may either replicate the surface pattern without defects
over large areas or a more complex reconstruction of the soft morphology at the patterned surface
occurs depending on the mismatch between the symmetry and length scale of surface pattern and bulk
morphology. Certain irregular patterns that do not have an analogue in the bulk phase diagram, can
be replicated by the adding "defectants" to the copolymer material. These are substances;e.g.,
homopolymers or nanoparticles; enrich at locations, where the substrate pattern deviates from the
bulk morphology, and thereby reduce the excess free-energy of these local structures, permitting
defect-free replication. Using computer simulation of soft, coarse-grained polymer models, we
investigate the directed assembly of copolymer materials on various surface patterns. The model
allows us to investigate large, three-dimensional systems with an experimentally relevant degree of
polymerization by computer simulations. Special methods for computing free-energy differences of
self-assembled morphologies and grain-boundaries will be discussed and applied to block copolymers
in thin films. The computer simulation provides a wealth of information about the three-dimensional
structure, its free energy, and also about the kinetics of structure formation.
* Ph.D. (1995) and Habilitation (1999) in theoretical physics from the Johannes Gutenberg-Universität in Mainz, Germany. He researched at the University of Washington, at the University of Mainz, at the Edinburgh Parallel Computing Centre, at the Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas of La Plata, at the Institute of Solid State Research of Jülich, at the University of California and at the Comisión Nacional de Energía Atómica. He was guest professor at the Universidad Nacional de General San Martin, assistant professor at the University of Mainz, and associate professor at the University of Wisconsin-Madison. He is presently university professor at the Institute for Theoretical Physcis at the Georg-August University of Göttingen. He was awarded with the Feodor Lynen fellowship from the Alexander von Humbodt Foundation, with the Sponsorship for the Research of the University of Mainz, with the Heisenberg fellowship of the German Science Foundation, with a Lichtenberg professorship from the Volkswagen Foundation and with the "John H. Dillon" Medal of the American Physical Society.