Interfacial Jamming in Complex Fluids Induced by Surface-Active Agents

Investigating the transport processes of nonimmiscible fluids, especially in the presence of surface-active agents, is crucial across various industries and environments.^1,2 By affecting interfacial dynamics, these agents can also lead to jamming-like behavior, where local movement stops not due to crowding in the bulk but because of obstruction at the interface. This study explores the fundamental mechanisms behind jamming in the oil-water system, both with and without surfactants and nanoparticles, using coarse-grained Dissipative Particle Dynamics (DPD) simulations.^3-6 We discuss how flow conditions, capillary pressure, and the presence of surface-active agents influence jamming behavior, especially at interfaces and in complex fluids, to optimize transport through confined spaces. Our simulations show that amphiphilic Janus nanoparticles and surfactants significantly change meniscus shape, movement, the onset of jamming, and the jamming location within a bottleneck-shaped channel. Jamming tends to happen beyond the constriction, rather than at the narrowest point. This position can be predicted either by applying a force balance or by minimizing the system's energy. Regarding the effect of nanoparticles, the rearrangement of NPs after jamming is also observed at the jamming point. Understanding these mechanisms offers strategic guidance for enhancing interfacial transport and system performance in both industrial and environmental applications.

References

1. S. Kaur and A. Roy, Environment, Development and Sustainability, 2021, 23, 9617-9640.

2. I. Gavrielatos et al., J. Petroleum Science and Engineering, 2017, 152, 664-674.

3. T. X. Nguyen et al. Polymers, 2022, 14, 543.

4. T. X. Nguyen, et al., The Journal of Physical Chemistry B, 2022, 126, 6314-6323.

5. T. X. Nguyen, et al., The Journal of Physical Chemistry B, 2024, 128, 3016-3026.

6. T. X. Nguyen, et al., ACS Applied Materials & Interfaces, 2025, 17, 27351-27365.