Paper Number
GR10
Session
Gallery of Rheology Contest
Title
Interfacial rheology and thin liquid films
Presentation Date and Time
October 13, 2021 (Wednesday) 6:30
Track / Room
Gallery of Rheology / Ballroom Pre Function
Authors
- Alicke, Alexandra (ETH Zurich, Department of Materials)
- Vermant, Jan (ETH Zurich, Materials Departement)
Author and Affiliation Lines
Alexandra Alicke and Jan Vermant
Department of Materials, ETH Zurich, Zurich, Switzerland
Speaker / Presenter
Alicke, Alexandra
Keywords
emulsions; flow-induced instabilities; foams; interfacial rheology; surfactants
Text of Abstract
The macroscopic stability of multiphase soft materials, such as emulsions and foams, is directly related to the microscopic stability of the films surrounding its droplets or bubbles. The drainage dynamics of these thin liquid films display an intricate balance between surface and bulk properties. In our research, we are interested in understanding the role of interfacial rheological properties on thin film drainage. For this, we typically carry out microfluidic scale experiments of nanometer-thick draining films and relate their behavior to results obtained from different interfacial rheology techniques. Here, we present a somewhat more literal and ludic representation of our scientific interests - inspired by careful observations during cleaning procedures and as a reminder that science is present even in the most trivial daily tasks. This sequence of macroscopic photographs shows the beautiful interference patterns that arise when a free-standing soap film forms in a double-wall ring geometry used for interfacial rheology. Both glycerol and surfactant were used to slow down drainage by increasing bulk viscosity and enhancing Marangoni flows, displaying a myriad of colors and patterns that reflect the nm-thickness inhomogeneities that emerge