Paper Number
IR10 My Program
Session
Interfacial Rheology, Surfactants, Foams and Emulsions
Title
Reducing emulsion drop deformation with low surface coverage: High yield particle interfaces
Presentation Date and Time
October 20, 2025 (Monday) 2:30
Track / Room
Track 5 / O’Keeffe + Milagro
Authors
- Abutalebi, Arsalan (Texas Tech University)
- Christopher, Gordon F. (Texas Tech University)
Author and Affiliation Lines
Arsalan Abutalebi and Gordon F. Christopher
Texas Tech University, Lubbock, TX 79410
Speaker / Presenter
Abutalebi, Arsalan
Keywords
colloids; emulsions; interfacial rheology
Text of Abstract
Due to their long-term stability, particle stabilized Pickering emulsions are used extensively across various industries. Commonly, stabilization is derived from fully particle covered, “armored” droplets. However, there is growing concern about the environmental impacts associated with increased global usage of micro- and nanoparticles, resulting in a desire to lessen their usage. It has been shown that particle laden bubbles with high yield stress interfaces can be stable at low surface concentrations. We wish to extend this mechanism to particle covered liquid droplets; however, creating high interfacial yield on o/w interfaces is challenging.
We build on our own previous work that demonstrated planar, o/w interfaces composed of charge bidisperse particles at low surface concentrations have larger interfacial yield stresses, viscoelastic moduli, relatively elasticity, and microstructure complexity compared to monodisperse interfaces. We than replicate bidisperse, planar, o/w particle laden interfaces onto dispersed water droplets in oil using a flow focuser microfluidic device that allows controlled delivery of bidisperse particle systems to the drop interface. Drop deformation during extensional flow and coalescence were studied. When comparing drops whose interfaces had high interfacial yield to those without, there was significant reduction in both deformation and number of coalescence events. This was observed to be true even at surface concentrations as low as 30%. In all cases, if interfacial yield was above 10-4 Pa*m, increased drop stability was observed. Such reduced deformation could significantly enhance emulsion stability and alter Pickering emulsion design.