Dispersion activity coefficient models. Part 3: A topology preserving group contribution model

The previously developed dispersion activity coefficient model (ACM) is extended from a molecular to a group contribution (GC) model providing results of equal accuracy as the molecular model. Contrary to other GC-ACMs the presented GC-ACM preserves the topology information of each molecule in the mixture. Therefore, in contrast to DISQUAC, UNIFAC or COSMOSAC, where the topology is eliminated by the assignment of groups or the construction of sigma-profiles, this new methodology makes it possible to quantify differences in phase behavior between isomers in a multicomponent mixture.