A GENERAL-APPROACH TO ASSOCIATION USING CLUSTER PARTITION-FUNCTIONS

A systematic and fundamental approach to associating mixtures is prese nted. It is shown how the thermodynamic functions may be computed star ting from a partition function based on the cluster concept such as oc curs in chemical theory. The theory provides a basis for and an extens ion of the existing chemical theory of (continuous) association. It is applicable to arbitrary association schemes. Analysis of separate cas es is not necessary. The assumptions that were made to allow the devel opment were chosen such as to make the principle of reactivity valid. It is this same principle that links various theories: the chemical th eory of continuous association, the lattice fluid hydrogen bonding mod el, and first-order perturbation theory. The equivalence between these theories in appropriate limits is shown in a general and rigorous way . The theory is believed to provide a practical framework for engineer ing modeling work. Binary interaction parameters can be incorporated. The association scheme is accounted for by a set of generic equations, which should facilitate robust implementation in computer programs.