Paper Number
PO40 

Session
Poster Session

Title
Self-similar growth of nanoscopic mesas in stratifying micellar foam films

Presentation Date and Time
October 12, 2022 (Wednesday) 6:30

Track / Room
Poster Session / Riverwalk A

Authors (Click on name to view author profile)

1. Xu, Chenxian (University of Illinois Chicago, Department of Chemical Engineering)
2. Zhang, Yiran (10X Genomics)
3. Kemal, Subinur I. (Abbott)
4. Sharma, Vivek (University of Illinois Chicago, Department of Chemical Engineering)

Author and Affiliation Lines (in printed abstract book)
Chenxian Xu¹, Yiran Zhang², Subinur I. Kemal³ and Vivek Sharma^1
1Department of Chemical Engineering, University of Illinois Chicago, Chicago, IL; ²10X Genomics, San Francisco, CA; ³Abbott, San Diego, CA

Speaker / Presenter 
Xu, Chenxian

Keywords
flow-induced instabilities; foams; surfactants

Text of Abstract
Freestanding films of soft matter exhibit stratification due to confinement-induced structuring and layering of supramolecular structures like micelles. Stratification in micellar films proceeds by the growth of thinner domains at the expense of surrounding thicker film, and local volume conservation leads to the formation of nanoscopic ridges at the moving front. The ridge often undergoes an instability leading to the nucleation of nanoscopic mesas, that grow and coalesce over time along the moving front. The shape and size of ridges and mesas in stratifying films are visualized and analyzed using interferometry, digital imaging, and optical microscopy (IDIOM) protocols, with unprecedented high spatial (thickness < 10 nm, lateral ~500 nm) and temporal resolution (< 1 ms). In this contribution, we analyze the shape evolution of mesas in an effort to develop a comprehensive understanding of drainage by stratification in micellar foam films, including the role played by the contribution of supramolecular oscillatory structural forces to disjoining pressure.