Phase Transitions Affected by Interconversion and Applications to Three Atomistic Models

We present a general description of phase separation driven by spinodal decomposition in a binary fluid with molecular interconversion of the components. We show that without a "source'' of interconversion the system always reaches macroscopic phase separation with the domain growth enhanced by interconversion (slow phase amplification). Addition of a source of interconversion drives the system away from equilibrium and creates the possibility for arrested phase separation - the existence of non-growing (steady-state) mesoscopic phase domains. We apply the theory to three different atomistic models: the model of Glotzer et al., where interconversion is provided only by a reaction source independent from phase separation; the model of Buldyrev et al., where the presence of an external source can cause arrested phase separation or phase amplification; and the model of Uralcan et al., where an internal source originates from unbalanced intermolecular forces. The theory is in agreement with the results of simulations performed for these models.