SAFT-P: A plaquette level perturbation for self-assembly in patchy colloids

TL;DR

SAFT-P is a new theoretical approach that models patchy colloids at the plaquette level, capturing local topology effects and improving predictions of phase behavior in complex self-assembling systems.

Contribution

It introduces a plaquette-level extension of SAFT that retains patch topology information and enhances modeling of self-assembly and phase behavior.

Findings

SAFT-P accurately predicts topology-dependent critical points.

It discriminates between particles with identical valence but different patch layouts.

Improves predictions in regimes lacking patch-specific interactions.

Abstract

We introduce SAFT-P, a plaquette-level extension of Statistical Associating Fluid Theory for patchy particles. By treating local clusters as associating superparticles and contracting their free energy back to monomer densities, SAFT-P retains information about patch topology that is lost in conventional SAFT. Grand-canonical Monte Carlo simulations of binary and ternary mixtures show that SAFT-P captures topology-dependent critical points and coexistence curves and discriminates between particles with identical valence but different patch layouts. Beyond topology, incorporating plaquette-scale correlations also improves predictions in regimes where patch specific interactions are absent. Results indicate that resolving correlations at the plaquette scale provides an analytical route to model complex condensates and self-assembly with topology-sensitive local structure.