Mixing-demixing transition and void formation in quasi-2D binary mixtures on a sphere

Area of Science:

• Surface science
• Materials science
• Physical chemistry

Background:

• Observed heterogeneous domain structures on cell and vesicle surfaces.
• Domain formation occurs due to molecule adsorption onto composite membranes.

Purpose of the Study:

• To model binary mixtures on spherical particle surfaces.
• To investigate the impact of miscibility and adsorbing particle (AP) addition on mixture structure.
• To quantify mixing and demixing effects induced by APs.

Main Methods:

• Developed a minimal quasi-2D model for binary mixtures on spherical surfaces.
• Introduced a geodesic mixing parameter (Ξ) to analyze AP effects.
• Analyzed void size distributions to understand void formation mechanisms.

Main Results:

• Defined the geodesic mixing parameter (Ξ) to distinguish AP-induced mixing/demixing.
• Demonstrated that APs and miscibility influence domain structure.
• Showed that AP-mixture interactions and miscibility control void formation, altering distribution tails.

Conclusions:

• The geodesic mixing parameter (Ξ) effectively quantifies AP influence on binary mixture structure.
• Void formation is governed by interplay between miscibility and AP-mixture interactions.
• The model provides a framework for understanding complex surface phenomena.