Paper Number
PO93 

Session
Poster Session

Title
The effect of polymer chain flexibility on the interfacial viscoelasticity at the air/water interface

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. Ashkenazi, Daniel (Ben Gurion University, Chemical Engineering)
  2. Alexandris, Stelios (FORTH, Institute of Electronic Structure and Laser)
  3. Vermant, Jan (ETH Zürich, Materials)
  4. Vlassopoulos, Dimitris (FORTH and University of Crete)
  5. Gottlieb, Moshe (Ben Gurion University, Chemical Engineering)

Author and Affiliation Lines (in printed abstract book)
Daniel Ashkenazi1, Stelios Alexandris2, Jan Vermant3, Dimitris Vlassopoulos4 and Moshe Gottlieb1
1Chemical Engineering, Ben Gurion University, Beer Sheva 8410501, Israel; 2Institute of Electronic Structure and Laser, FORTH, Heraklion 70013, Greece; 3Materials, ETH Zürich, Zürich, Switzerland; 4FORTH and University of Crete, Heraklion, Greece

Speaker / Presenter 
Ashkenazi, Daniel

Keywords
experimental methods; interfacial rheology

Text of Abstract
Fluid interfaces play a crucial role in many biological and industrial processes. Exploration of the poorly understood interplay between polymer molecular characteristics, polymer organization at the interface, and their effect on the mechanical properties of the interface is a prerequisite for a proper design for a multitude of interface-dominated processes. Insoluble polymers are an interesting system to examine at liquid interfaces due to the ability to distinguish the effect of different attributes of the polymer on the morphological and rheological properties of the interface. Furthermore, when one wishes to impart viscoelastic properties to interfaces, using polymers seems as a natural choice. This contribution shows that polymers with different chain flexibility follow significant interfacial rheology and microstructure variations. A comparison between PDMS and flexible polyacrylates such as poly(n butyl acrylate) were found to have microstructure composed of discrete islets of polymer, with no discernible interfacial rheology. Whereas interfacial rheology measurements for relatively rigid polymethyl acrylates such a poly(tert-butyl methacrylate) show a transition from a liquid-like to elastic solid-like interface and uniform sheet morphology. The differences in the rheology and microstructure of the polymer-laden interfaces is illustrated by a combination of classical rectangular Langmuir-Pockels trough, Brewster's angle microscope, and interfacial shear rheometers.