Poly-liquid behaviors of self-associating fluids and mesoscopic aggregation in liquid solutions.

In conflict with standard notions of thermodynamics, mesoscopically sized inclusions ("clusters") of a solute-rich liquid have been observed in equilibrated solutions of proteins and other molecules. According to a complexation scenario proposed earlier, a steady-state ensemble of finite-sized droplets of a metastable solute-rich liquid can emerge in a solution, if the solute molecules can form transient complexes with each other and/or solute. Here, we solve for the thermodynamics of an explicit model of a self-associating fluid in which particles can form transient dimers.