The interplay between flow and attractive interactions in colloidal gels results in complex particle trajectories and velocity profiles that are not evident from bulk rheological measurements. We use high-speed confocal microscopy to investigate the local velocity of a low volume fraction (ϕ = 0.20) thermogelling nanoemulsion system as it flows through a cylindrical capillary at temperatures below and above the gel point. The nanoemulsions are composed of poly(dimethyl siloxane) droplets in a continuous phase of sodium dodecyl sulfate, de-ionized water, and a gelator molecule, poly(ethylene glycol diacrylate). The trajectories of fluorescent polystyrene tracer beads in the oil-rich domains are tracked using two-dimensional image processing. While the velocity profiles agree with those computed from rheometry measurements for nanoemulsion suspensions below the gel point temperature, increasing attractive interactions above the gel point results in statistically significant deviations. Specifically, the velocity measurements indicate a higher yield stress and a larger degree of shear thinning than expected from bulk rheology measurements, resulting in a more plug-shaped velocity profile as temperature and associated interdroplet attraction increase. These deviations from theoretical predictions are likely due to structural heterogeneity. Confocal microscopy images show that small, fluidized clusters are found in high shear rate regions near the capillary walls, while large dense clusters form in low shear rate regions closer to the center of the capillary.
Skip Nav Destination
Local velocity of thermoresponsive colloidal gels in rate-driven flow
Article navigation
March 2021
Research Article|
March 26 2021
Local velocity of thermoresponsive colloidal gels in rate-driven flow
Special Collection:
Dynamics of Out-of-Equilibrium Soft Materials
Kristine M. Smith
;
Kristine M. Smith
Department of Chemical and Biomolecular Engineering, North Carolina State University
, Raleigh, North Carolina 27695, USA
Search for other works by this author on:
Adriana San-Miguel
;
Adriana San-Miguel
Department of Chemical and Biomolecular Engineering, North Carolina State University
, Raleigh, North Carolina 27695, USA
Search for other works by this author on:
Lilian C. Hsiao
Lilian C. Hsiao
a)
Department of Chemical and Biomolecular Engineering, North Carolina State University
, Raleigh, North Carolina 27695, USA
a)Author to whom correspondence should be addressed: [email protected]
Search for other works by this author on:
a)Author to whom correspondence should be addressed: [email protected]
Note: This paper is part of the special topic, Dynamics of Out-of-Equilibrium Soft Materials.
Physics of Fluids 33, 033113 (2021)
Article history
Received:
December 28 2020
Accepted:
February 15 2021
Citation
Kristine M. Smith, Adriana San-Miguel, Lilian C. Hsiao; Local velocity of thermoresponsive colloidal gels in rate-driven flow. Physics of Fluids 1 March 2021; 33 (3): 033113. https://doi.org/10.1063/5.0042109
Download citation file:
Pay-Per-View Access
$40.00
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Citing articles via
Chinese Academy of Science Journal Ranking System (2015–2023)
Cruz Y. Li (李雨桐), 李雨桐, et al.
Fall and breakup of miscible magnetic fluid drops in a Hele–Shaw cell
M. S. Krakov (М. С. Краков), М. С. Краков, et al.
Referee acknowledgment for 2024
Alan Jeffrey Giacomin
Related Content
Probing structure in colloidal gels of thermoreversible rodlike virus particles: Rheology and scattering
J. Rheol. (September 2012)
Microstructure and nonlinear signatures of yielding in a heterogeneous colloidal gel under large amplitude oscillatory shear
J. Rheol. (September 2014)
Kinetic studies of chemical shrinkage and residual stress formation in thermoset epoxy adhesives under confined curing conditions
AIP Conference Proceedings (May 2015)
Discussion of 010405JOR by J. Kim et al.
J. Rheol. (September 2014)
Effect of Hyaluronic Acid on the Self Assembling Behaviour of PEO‐PPO Copolymers in Aqueous Solution
AIP Conference Proceedings (July 2008)