Paper Number
EF11
Session
Emulsions, Foams, and Interfacial Rheology
Title
Transport of block copolymers to oil-water interfaces and impact on interfacial properties
Presentation Date and Time
October 9, 2017 (Monday) 4:10
Track / Room
Track 1 / Crystal A
Authors
- Davidson, Michael L. (Carnegie Mellon University, Chemical Engineering)
- Gottlieb, Moshe (Ben-Gurion University of the Negev, Chemical Engineering)
- Walker, Lynn M. (Carnegie Mellon University, Chemical Engineering)
Author and Affiliation Lines
Michael L. Davidson1, Moshe Gottlieb2, and Lynn M. Walker1
1Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213; 2Chemical Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel
Speaker / Presenter
Davidson, Michael L.
Text of Abstract
Amphiphilic block copolymers are a broad class of materials that have been used to supplement or replace aliphatic surfactants. Although industrial use has been popular for several decades, determining structure/property relationships for wettability, detergency, and emulsification power is still an active area of research. We have characterized the adsorption behavior of two structures of block copolymer (diblocks of PEO-PDMS and triblocks of PEO-PDMS-PEO, where PEO is polyethylene oxide and PDMS is polydimethylsiloxane) at several fluid/fluid interfaces (water and a series of oils including isooctane, dodecane, silicone oil) using interfacial tensiometry and dilatational rheometry. The effects of interfacial curvature on interfacial tension and dilatational modulus will be discussed. Equilibrium interfacial layers have been characterized for irreversibility by solvent exchange, and these results will be compared with stress-relaxations performed by step changes in interfacial area. Ultra-low surface tensions have been observed at the silicone oil/water interface alongside the spontaneous formation of microbubbles. We explore this for several block copolymers and compare with bulk phase behavior and emulsion stability.