Hyperuniformity in ternary fluid mixtures: the role of wetting and hydrodynamics

Abstract

Phase separation in multicomponent fluids is central to understanding the organization of complex materials and biological structures. The multicomponent Cahn-Hilliard-Navier-Stokes (CHNS) equations offer a robust framework for modeling such systems, capturing both diffusive dynamics and hydrodynamic interactions. In this work, we investigate hyperuniformity---characterized by suppressed large-scale density fluctuations---in ternary fluid mixtures. These serve as prototypical example of multicomponent fluids and are governed by the ternary CHNS equations. Using large-scale direct numerical simulations in two dimensions, we systematically explore the influence of wetting conditions and hydrodynamic effects on emergent hyperuniformity. Similar to binary systems we observe that the presence of hydrodynamics weakens the hyperuniform characteristics. However, also the wetting properties have an effect. We find that in partial wetting regimes, all three components exhibit comparable degrees of hyperuniformity. In contrast, for complete wetting scenarios, where one component preferentially wets the other two, the wetting component displays a significant reduction in hyperuniformity relative to the others. These findings suggest that wetting asymmetry can act as a control parameter for spatial order in multicomponent fluids.