MATERIALS SCIENCE AND CHEMISTRY

A supramolecular polymer (SMP) has functional groups which interact with each other to form a physical bond. In contrast to chemical bonds, the bond formation in an SMP is reversible and the resulting aggregate morphology in a SMP melt thermally fluctuates. For functional groups allowing only a pairwise association, a ring aggregate is highly important as a ring topologically reduces the mobility of surrounding linear polymers by threading. Using molecular dynamics simulations of SMPs, the effect of ring aggregates on the system relaxation time governing rheological response was investigated. It was shown that the presence of ring aggregates slows down rheological response as measured by a reduction of the so-called entanglement length.

Metallic glasses are very strong and nonetheless elastic, making them appealing for diverse engineering applications. Despite these favourable properties, the failure of metallic glasses sets in directly after the elastic limit, making them brittle. In this project, scientists at the Technische Universität Darmstadt investigate nanostructured metallic glasses as a possible solution to this problem using large-scale molecular dynamics simulations.