MATERIALS SCIENCE AND CHEMISTRY

Being able to handle and manipulate large molecules or other nano-objects in a controlled manner is a central ingredient in many bio- and nanotechnological applications. One increasingly popular approach, e.g., in microfluidic setups, is to use  dielectrophoresis. Here, the nano-objects are exposed to an alternating electric field, which polarizes them. Depending on the polarization, they can then be grabbed and moved around or trapped by an additional field. However, the mechanisms governing the polarization of the objects, which are typically immersed in a salt solution, are very complicated. Simulations allow to disentangle the different processes that contribute to the polarizability and to assess the influence of key factors such as AC…

A team from the physics department of the Johannes Gutenberg University, Mainz, has investigated nucleation processes and interfacial properties of colloidal crystals. Nucleation is omnipresent in our daily life and describes events as diverse as the formation of rain in clouds, the crystallization of proteins or the growth of nano-particles. The studies undertaken using supercomputers Hazel Hen and Hornet of HLRS Stuttgart contribute towards a more fundamental understanding of these processes and the underlying theoretical foundation.

The properties of water at interfaces such as liquid/vapor and liquid/solid interfaces are relevant to many fundamental processes in atmospheric chemistry as well as in biology such as protein folding and aggregation mechanisms. Leveraging HPC resources available at the HLRS, researchers at the Johannes Gutenberg University in Mainz apply ab initio molecular dynamics simulations (AIMD) in both equilibrium and non-equilibrium conditions, as AIMD simulations are an ideal tool for accurate descriptions of heterogeneous condensed phase systems. By simulating the behaviour of water at the nanoscale, the scientists aim for a better understanding about its properties at the interface.

To study phase separation of colloid-polymer mixtures after a quench into the two phase region in a slit-pore geometry, a team of scientists from the Institute of Physics of the Johannes Gutenberg-Universität Mainz and the Forschungszentrum Jülich employ a multiscale approach, the so-called "multiparticle collision dynamics" method using GCS supercomputers.