Unusual liquid phases for indented colloids with depletion interactions

TL;DR

This paper investigates indented colloids with depletion interactions, revealing how lock-and-key bonding influences phase behavior, leading to porous liquids with large voids and potential for controlled porous structure assembly.

Contribution

It introduces a detailed analysis of phase transitions in indented colloids, highlighting the impact of specific binding on phase properties and porous structure formation.

Findings

Critical point shifts to lower density with increased lock-and-key binding.

Liquid phase exhibits large percolating voids, indicating porosity.

Bond network topology critically influences system properties.

Abstract

We study indented spherical colloids, interacting via depletion forces. These systems exhibit liquid-vapor phase transitions whose properties are determined by a combination of strong "lock-and-key" bonds and weaker non-specific interactions. As the propensity for lock-and-key binding increases, the critical point moves to significantly lower density, and the coexisting phases change their structure. In particular, the liquid phase is "porous", exhibiting large percolating voids. The properties of this system depend strongly on the topological structure of an underlying bond network: we comment on the implications of this fact for the assembly of equilibrium states with controlled porous structures.