This event has passed.
Tuesday, April 16, 2024 – 12:00PM to 1:00PM
Presenter
Harm-Anton Klok
Thomas Lord Department of Mechanical Engineering & Materials Science welcomes Prof. Dr. Harm-Anton Klok, Ecole Polytechnique Fédérale de Lausanne (EPFL), to present a MEMS Seminar: ""Mechanochemistry of Solvent-Swollen Surface-Grafted Polymer Brushes, and Polymer Networks."
Abstract: Mechanical forces have been known for a long time to facilitate bond cleavage reactions in polymer materials. Typically, the impact of force on the stability and reactivity of polymers is investigated by subjecting polymers to relatively high mechanical forces such as those that are the result of ultrasonication, high shear flow fields, or that are exerted on polymers during tensile testing or mastication processes. Much less investigated, in contrast, are the effects of much weaker forces, such as those that are generated by solvent swelling of crosslinked networks, on the stability of polymers. This talk will highlight recent work from our laboratory that indicates that solvent-swelling of surface-grafted polymer brush films, or of covalently crosslinked polymer networks, mechanochemically accelerates chemical reactions, which can lead to bond cleavage at polymer brush interfaces, or trigger polymer network degradation.
Bio: Harm-Anton Klok is Full Professor at the Institutes of Materials, and Chemical Sciences and Engineering at the Ecole Polytechnique Fédérale de Lausanne (EPFL) (Lausanne, Switzerland). He studied chemical technology at the University of Twente (Enschede, The Netherlands) from 1989 to 1993 and received his Ph.D. in 1997 from the University of Ulm (Germany) after working with Martin Möller. After postdoctoral research with David N. Reinhoudt (University of Twente) and Samuel I. Stupp (University of Illinois at Urbana-Champaign, USA), he joined the Max Planck Institute for Polymer Research (Mainz, Germany) in early 1999 as a project leader in the group of Klaus Müllen. In November 2002, he was appointed to the faculty of EPFL. Since 2012 he is Director of the Institute of Materials (~ Department Head) and also directs the Molecular and Hybrid Materials Characterization Center at EPFL. His research interests include polymer surface and interface science, polymer nanomedicine and polymer synthesis and functionalization.