Fluid of Janus molecules between two walls: the solvation force

Area of Science:

• Colloid and Surface Science
• Statistical Mechanics
• Computational Physics

Background:

• Janus particles exhibit distinct properties due to their spatially varying surface interactions.
• Confining such particles between surfaces introduces complex behaviors influenced by particle-wall and particle-particle interactions.
• Understanding solvation forces is crucial for designing and controlling systems with confined anisotropic particles.

Purpose of the Study:

• To investigate the solvation forces acting on Janus particles confined between planar walls.
• To analyze the influence of wall properties (identical vs. competing) on particle behavior.
• To explore the role of anisotropic interparticle interactions and external parameters (temperature, density) on confined Janus particle systems.

Main Methods:

• Density functional theory (DFT) combined with fundamental measure theory (FMT).
• Mean-field approximation for anisotropic interparticle interactions.
• Modeling Janus particles as spheres with attractive and repulsive domains, with orientation described by internal degrees of freedom.

Main Results:

• Solvation forces were calculated for Janus particles in both identical and Janus-like pores.
• The orientational structure of confined Janus particles was analyzed.
• Dependencies of solvation force and orientational structure on surface field competition, temperature, and density were studied.

Conclusions:

• Anisotropic interactions between confined Janus particles significantly affect solvation forces.
• The nature of the confining walls (competing or identical) plays a critical role in determining solvation forces.
• The interplay between surface fields and interparticle interactions dictates the behavior of confined Janus particles.