Nanoparticle Dynamics and Aggregation Behavior in Nanofluids: A Particle-scale Simulation Study

Researchers at South China University of Technology have conducted a comprehensive study on nanoparticle dynamics and aggregation behavior in nanofluids, shedding light on the complex factors affecting these processes. By developing two key dimensionless numbers, the Brownian number (Br) and the adhesion number (Ad), the team has innovatively condensed the complex factors into a manageable framework. Simulation results reveal that Brownian motion and adhesion exert nonmonotonic effects on aggregation, with both factors influencing the outcome in different ways. The study provides valuable insights into predicting the aggregation behavior of nanofluids under complex conditions and has been peer-reviewed.

Key Takeaways:

• The study focuses on particle-scale understanding of nanoparticle dynamics and aggregation behavior in nanofluids, which is crucial for accurately characterizing their functionality.
• The research team developed two key dimensionless numbers, the Brownian number (Br) and the adhesion number (Ad), to describe the complex factors affecting nanoparticle aggregation.
• Simulation results revealed that both Brownian motion and adhesion exert nonmonotonic effects on aggregation, promoting or inhibiting the process depending on their intensity.
• The study proposes an aggregation phase diagram as a function of Br and Ad, providing a valuable tool for predicting aggregation behavior under complex conditions.
• The research has been peer-reviewed and validates the findings through experiments.
• The study's outcomes have significant implications for the development of nanofluids and other nanotechnology applications.

Statistics:

• The research was supported by the National Natural Science Foundation of China (NSFC), Guangzhou Science and Technology Plan Project, China, Basic and Applied Basic Research Foundation of Guangdong Province, China.
• The study involved simulations of typical particle dynamics using discrete element method coupled with a lattice Boltzmann model and immersed moving boundary (DEM-LBM-IMB).
• The simulation results revealed that Brownian motion promotes aggregation by increasing the frequency of particle collisions, but excessive Brownian motion beyond the interparticle adhesion threshold reduces the adhesion ratio after collisions and amplifies particle separation.
• The study validated the aggregation phase diagram through experiments and provided insights into predicting the aggregation behavior of nanofluids under complex conditions.

Sources:

• Nanoparticle Dynamics and Aggregation Behavior In Nanofluids: a Particle-scale Simulation Study. Physical Review E, 2025;112(1). Physical Review E can be contacted at: Amer Physical Soc, One Physics Ellipse, College Pk, MD 20740-3844, USA.
• Rong-Rong Cai, et al. Investigators at South China University of Technology Detail Findings in Nanoparticles (Nanoparticle Dynamics and Aggregation Behavior In Nanofluids: a Particle-scale Simulation Study). Nanotechnology Weekly. August 25, 2025; p 403.