The Eindhoven University of Technology (TU/e), Department of Mechanical Engineering has a vacancy for a PhD student on 'Molecular simulation of chemical degradation in glassy polymers' in the Polymer Technology group.
We are looking for a PhD student for a four-year research project on the topic of molecular simulation of chemical degradation in glassy polymers. In this computational/theoretical project you will develop and perform molecular simulations (rare-event sampling, transition-state theory, network dynamics) in order to study chemical degradation of glassy polymers by small penerant molecules.
In the course of physical ageing, or under conditions of oxidative stress, glassy polymers (e.g., polycarbonate) undergo damage initiation and progression in the form of microcracks which finally lead to ultimate damage and loss of their good mechanical properties. Even worse, exposure of polymers to aggressive chemicals or UV-irradiation accelerates chemical degradation. For the functionality of the polymer product to be ensured, the polymeric matrix must remain sufficiently stable throughout the desired life-time and stand up to the thermo-mechanical chemical stresses which thereby arise. However, a bottom-up (i.e., molecular-level based) understanding of how glassy polymers interact with different chemical environments is still missing.
This PhD project is part of a larger project funded by the Dutch Polymer Institute (http://www.polymers.nl
): While this PhD project is concerned with chemical degradation, another researcher is working on the effect of UV-irradiation. Since both projects make use of the same underlying technique, a close collaboration is essential and of mutual benefit.
Since ageing mechanisms affect the polymer at the molecular scale, investigation of the change in macroscale properties using atomistically-detailed molecular simulations can provide crucial insights into the processes of physical and chemical ageing (this project), as well as UV-induced degradation. Predictions obtained from molecular modelling can limit the need for expensive and time-consuming application tests.
The major complication of using molecular simulations for chemical reactions is the enormous disparity in time-scales. Therefore, instead of using conventional molecular dynamics, an innovative methodology has been developed recently, allowing molecular simulation of polymeric glasses at long time-scales, solely based on their atomistic structure and chemistry, at realistic conditions; this methodology is based on rare-event sampling (transitions between minima in energy-landscape, via saddle-points), using transition-state theory, and network dynamics. This project will use this technique to study the chemical reactions in glassy polymers, for specific systems of industrial relevance.