Paper Number
PL2
Session
Plenary Lectures
Title
Do interfaces matter in rheology?
Presentation Date and Time
October 12, 2021 (Tuesday) 8:30
Track / Room
Plenary Lectures / Ballroom 5-6-7
Authors
- Vermant, Jan (ETH Zurich, Materials Departement)
Author and Affiliation Lines
Jan Vermant
Materials Departement, ETH Zurich, Zurich 8093, Switzerland
Speaker / Presenter
Vermant, Jan
Keywords
interfacial rheology
Text of Abstract
Dealing with interfaces in rheology and fluid mechanics is usually achieved using the Gibbs sharp interface approach, with the stress boundary condition being the way in which we can efficiently describe its effects. This works, even when interfaces become structured and have their own intrinsic rheological response. However, understanding the rheological response of an interface can be challenging due to the unavoidable coupling with the surrounding bulk phases (which act as sinks for momentum) and the fact that interfaces can be compressible, rendering their response more complicated. Our ability to measure the interfacial rheological properties has progressed much over the last years, and we also have a better understanding of its - sometimes subtle - effects, e.g. during the thinning of of liquid films, by using an interplay of experiments and computational interfacial rheology. Understanding how the material functions influence thin film stability we can engineer these properties, building in for example a yield stress, strong elastic reponses into the interface, using many of the ideas and elements of the toolbox that we have in bulk rheology. These can be used to impart stability to multiphase systems in unusual manners However, we also may want to try to a chieve the opposite, e.g. keeping interfaces fluid even when they become crowded such as in cell membranes. In this talk I hope to take you on a journey from fundamentals to applications, coming back to the open questions concerning a simple boundary condition.