2026/05/01 by H Wang, Shiteng Wang, Yi Cheng · 1 voice
Engineering · Medicine · #Blood properties and coagulation #Innovative Microfluidic and Catalytic Techniques Innovation #Lattice Boltzmann Simulation Studies
paper · doi:10.1063/5.0321035
openalex publication_date 2026/05/01 · openalex created_date 2026/05/22 · openalex updated_date 2026/06/26
Mixing of miscible fluids with distinct interfacial tensions within microdroplets is a ubiquitous yet fundamentally important phenomenon in natural systems and microfluidic applications; however, the processes with mixing-induced dynamic interfacial tension have remained largely unexplored. Here, we used a ternary color-gradient lattice Boltzmann model to investigate the mixing of binary miscible phases with equal molecular mass inside microdroplet under the effect of concentration-dependent dynamic interfacial tension, demonstrating the coupled evolution of mixing, dynamic interfacial tension, interfacial energy, and flows. Simulations show that, in a static droplet, interfacial tension asymmetry generates tangential flows, driving the higher-interfacial-tension component rapidly toward the droplet interior, to reduce the total interfacial energy to its minimum, and enhancing mixing efficiency with a cashew-like concentration pattern. Extending the analysis to the formation and subsequent flow of binary-miscible-component droplet in microchannels, the influence of interfacial tension contrasts of two miscible dispersed phases against the continuous phase on internal mixing and droplet sizes was systematically examined over various diffusion coefficients. The interfacial-tension-driven flows are found to break the symmetric internal circulation inside droplet and that markedly enhance mixing, while increasing the interfacial tension contrast leads to a slight reduction in the droplet size. For rapid binary diffusion, the interfacial tension asymmetry is quickly relaxed, rendering its impact on flow and mixing insignificant.