Separation and gelation in associated systems with thermoreversible chemical bonds

Possible types of separation curves for a binary solution of chemically interacting molecules in a neutral solvent have been analyzed within the statistical model. It has been shown that the variation of the model parameters characterizing the energy and entropy of chemical bonds makes it possible to describe most of the possible types of solubility curves within the unified formalism. It has been demonstrated that the sol-gel transition for the case where the reactivity of molecules depends on the number of bonds can occur as a first-order phase transition; in the opposite case, gelation is a purely geometrical percolation transition.