Phase segregation dynamics of a chemically reactive binary mixture

We investigate a model system of a chemically reactive binary mixture, where the simple reaction A between the two constituents of the mixture occurs simultaneously with spinodal decomposition. The competition between the thermodynamic short-range attractive and the reactive long-range repulsive interactions leads to the formation of steady-state patterns. In the case of equal forward and backward reaction rates the steady-state average domain width, R_, scales with the reaction rate, , as R_ (1{) }^s, where the exponent s equals approximately 13 for low rates and equals exactly for high rates. These exponent values and the variation of the maximum amplitude of the order parameter with the reaction rate can be derived by minimizing the free energy in a square wave and a single mode approximation, respectively. The phase segregation dynamics is simulated numerically using the appropriate Langevin equation.