Liquid-vapor transition driven by bond disorder

We report grand-canonical Monte Carlo simulations of an equimolar mixture of hard colloids coated with long polymers that have a complementary functionalization. Such systems have the potential to function as self-healing materials. Under conditions where the complementary polymer ends are strongly associated, we observe a first-order vapor-liquid transition from a dilute gas of colloidal dimers to a dense, liquidlike phase. This transition is driven exclusively by the increase in entropy associated with bond disorder—an effect that was predicted theoretically by Zilman et al. [Phys. Rev. Lett. 91, 015901 (2003)]. Our simulations rationalize experimental observations by Schmatko et al. [Soft Matter 03 (2007) 703.