The rate of entropy production as an evolution criterion in chemical systems: I. Oscillating reactions

Abstract

Three chemicals oscillating models were chosen to be studied: Autocatalator, Brusselator and Oregonator. All of them exhibit an exotic behavior during the evolution of its intermediary species, in the form of temporal or spatial periodic oscillations (under determined conditions). Models were numerically integrated, by using Gear's algorithm.It was shown that an evolutive criterion for such systems could be sought from the Eulerian derivative of the rate of entropy production respect to time as a function of the control parameters of the system.Thus, during evolution, such chemical systems, far from the thermodynamic equilibrium, go through stationary states, qualitatively different, as a result of Hopf's bifurcation. This gives rise to self-organization and the rate of entropy production in each state is decreased in comparison with the previous one.