Paper Number
PO7
Session
Poster Session
Title
Thermal processing of thermogelling nanoemulsions as a route to tune material properties
Presentation Date and Time
October 17, 2018 (Wednesday) 6:30
Track / Room
Poster Session / Woodway II/III
Authors
- Cheng, Li-Chiun (Massachusetts Institute of Technology)
- Swan, James (Massachusetts Institute of Technology)
- Doyle, Patrick S. (Massachusetts Institute of Technology, Department of Chemical Engineering)
Author and Affiliation Lines
Li-Chiun Cheng, James Swan, and Patrick S. Doyle
Massachusetts Institute of Technology, Cambridge, MA 02139
Speaker / Presenter
Cheng, Li-Chiun
Text of Abstract
Soft matter systems have properties which depend on their processing history. It is generally accepted that material properties can be finely tuned by carefully directing self-assembly. However, for gelling colloidal systems, it is difficult to characterize such path-dependent effects since the colloidal attraction is often provided by adding another component to the system. Therefore, studies of and an understanding of the role of processing on the material properties of attractive colloidal systems are largely lacking. In this work, we systematically studied how processing greatly influences the properties and the microstructures of model attractive colloidal systems. We perform experiments using a thermogelling nanoemulsion as a model system where the isotropic attraction can be precisely tuned via the temperature. The effects of processing conditions on gel formation and properties is tested by performing well-designed sequential temperature jumps. By properly controlling the thermal history, we demonstrate that properties of colloidal gels can be beyond the limit set by direct quenching, which has been a major focus in literature, and that otherwise slow aging of the system associated with a decrease in elasticity can be prevented. Our results provide new experimental evidence of path-dependent rheology and associated microstructures in attractive colloidal systems and provide guidance to future applications in manufacturing complex colloid-based materials