On the Thermodynamics of Chain Fluids from Simulation and the Heteronuclear Statistical Associating Fluid Theory

The SAFT-VR equation of state is extended to treat heteronuclear chain fluids, in particular we focus on symmetric and asymmetric diblock chains. The chain molecules studied are composed of segments of different size and/or energies of interaction. Both symmetric and asymmetric systems are considered. The theoretical predictions are compared with isothermal-isobaric and Gibbs ensemble Monte Carlo simulation data. Excellent agreement is obtained between the hetero-SAFT-VR predictions and the simulation data, validating the use of the SAFT-VR approach for heteronuclear chains in more realistic models of polymers and small molecules composed of different functional groups. In the SAFT approach molecules composed of different functional groups are typically described by a model chain composed of homo-nuclear segments; the heterogeneity is taken into account through effective parameters. We will present preliminary results that use the heteronuclear SAFT-VR approach to more realistically describe real molecules.