Molecular theory for the phase equilibria and cluster distribution of associating fluids with small bond angles

TL;DR

This paper introduces a new molecular theory for associating fluids that incorporates small bond angle effects, validated through simulations, and reveals significant impacts on phase behavior and liquid-vapor transitions.

Contribution

The paper presents a novel theoretical framework that accounts for small bond angles, steric hindrance, ring formation, and double bonding in associating fluids, validated against Monte Carlo simulations.

Findings

Theory accurately predicts phase diagrams of patchy colloids.

Bond angle significantly influences the existence of liquid-vapor transition.

Small bond angles affect cluster formation and phase behavior.

Abstract

We develop a new theory for associating fluids with multiple association sites. The theory accounts for small bond angle effects such as steric hindrance, ring formation and double bonding. The theory is validated against monte carlo simulations for the case of a fluid of patchy colloid particles with three patches and is found to be very accurate. Once validated, the theory is applied to study the phase diagram of a fluid composed of three patch colloids. It is found that bond angle has a significant effect on the phase diagram and the very existence of a liquid - vapor transition.