Model of Thermally Expanded Graphite Formation under the Effect of Intercalate

Abstract

A thermodynamic model for describing the thermal expansion of intercalated graphite is proposed. An individual intercalate molecule (which, being in an electron state with different energy, can be bound to graphene planes by two elastic bonds of similar stiffness, or move freely between the planes, striking elastically against the walls) is considered as an element of a statistical ensemble. A relation for the statistical distribution of the states of intercalate molecules in intercalated graphite is obtained. The existence of a phase transition between the states that describes the formation of thermally expanded graphite is demonstrated by analyzing its distribution.