Long-range interaction between hydrophilic surfaces immersed in a hydrophobic fluid containing a hydrophilic component at low concentration

Behavior of a hydrophobic fluid containing a hydrophilic component at low concentration, which is confined between macroparticles separated by distance L, is analyzed using the reference interaction site model and hypernetted-chain theory. When the hydrophilicity of the macroparticle surface is sufficiently high, the following is observed. A layer within which particles of the hydrophilic component are enriched is formed around each macroparticle. As L decreases the two enriched layers within the confined domain continue to grow, eventually leading to a phase transition. The range of the macroparticle interaction induced can be far longer than the molecular scale.