Dr. Karol Palczynski "Molecular Dynamics Simulations of Condensed Phases: Molecular Crystals and Polymer Glasses"
Helmholtz Zentrum Berlin für Materialien und Energie, Germany
What |
|
---|---|
When |
Nov 21, 2018 from 02:15 PM to 03:00 PM |
Where | Seminarraum A, FMF, Stefan-Meier-Str. 21, Freiburg |
Add event to calendar |
vCal iCal |
Most opto-electronic and mechanical properties of molecular materials such as organic semiconductor devices and plastics are determined by the structure and alignment of the molecules in their condensed phases. Structure and alignment, in turn, depend on the interactions between the molecules. Molecular dynamics (MD) simulations, in which the interatomic forces are calculated by numerically solving a classical many-body Hamiltonian, will be a great help in predicting the condensed-phase structures of yet unexplored materials in the future.
In the present, we are paving the way to that goal by exploring how established theories and simulation methods can be applied in new ways to link experimentally accessible macroscopic properties of condensed phases to their microscopic origins.
In this talk, I will present two of our most exciting projects to that end.
We have demonstrated that MD simulations using a well-balanced non-polarizable force field and careful simulated cooling can be employed to grow molecular crystals of para-sexiphenyl molecules with experimentally consistent structures and solid to liquid-crystal phase behavior over a wide temperature range [1].
We have also developed an expeditious method for parameterizing a simple yet surprisingly powerful coarse-grained bisphenol-A polycarbonate model. It successfully reproduced the thermal expansion behavior, the glass transition temperature as a function of the molecular weight, and several elastic properties [2].
We regard work like this as a key requirement for targeted material design in the future.
[1] Cryst. Growth Des., 2014, 14, 3791−3799, dx.doi.org/10.1021/cg500234r
[2] Phys. Rev. Mat. 1, 2017, 043804, dx.doi.org/10.1103/PhysRevMaterials.1.043804
invited by Prof. Joachim Dzubiella