Paper Number
PO12 

Session
Poster Session

Title
A theoretical model for thermoresponsive nanoemulsions with polymer bridging interactions

Presentation Date and Time
October 17, 2018 (Wednesday) 6:30

Track / Room
Poster Session / Woodway II/III

Authors (Click on name to view author profile)

  1. Ryu, Brian K. (Stanford University, Chemical Engineering)
  2. Nguyen, Tuan (University of California, Santa Barbara)
  3. Fenton, Scott (University of California, Santa Barbara)
  4. Helgeson, Matthew E. (University of California, Santa Barbara)
  5. Zia, Roseanna N. (Stanford University, Chemical Engineering)

Author and Affiliation Lines (in printed abstract book)
Brian K. Ryu1, Tuan Nguyen2, Scott Fenton2, Matthew E. Helgeson2, and Roseanna N. Zia1
1Chemical Engineering, Stanford University, Stanford, CA, CA 94305-4125; 2University of California, Santa Barbara, Santa Barbara, CA 93106

Speaker / Presenter 
Ryu, Brian K.

Text of Abstract
Since antiquity, thermal processing strategies that harness slow dynamics to kinetically arrest phase separations have existed for molecular materials such as metal alloys and ceramics. Through a sophisticated set of quenching, annealing, and tempering strategies, these techniques have led to mesoscopic structures and superior mechanical properties that are otherwise unattainable. For colloidal materials, however, the separation of time scales between colloids and the suspended fluid introduces slow kinetics, thereby complicating the thermal processing of colloidal solids. As a result, thermal processing methods have remained elusive for colloidal systems. The key challenges of studying colloidal materials arise from the difficulty in achieving precise control of interparticle interactions in situ, and in dynamically simulating systems sufficiently large for extended times to observe kinetic and phase behavior while faithfully replicating the physics in silico. In this study, we present results from our large-scale dynamic simulations of a reversible, thermoresponsive bridging nanoemulsion system, in which polymers in the aqueous continuous phase bridge oil droplets via hydrophobic interactions. Helgeson and co-workers have utilized neutron scattering and rheology to establish an interactive potential that accurately describes the model system phase behavior, where the potential parameters that correspond to the depth and range of attraction are modulated in experiment by temperature. In this computational work, we carefully match the polymer bridging interaction to the model for simulation to accurately replicate the kinetics of phase behavior, beginning with the development, testing, and validation of the in silico, temperature-dependent attractive potential.