Molecular dynamics study of phase separation in fluids with chemical reactions

We present results from the first d = 3 molecular dynamics (MD) study of phase-separating fluid mixtures (AB) with simple chemical reactions (A reversible arrow B). We focus on the case where the rates of forward and backward reactions are equal. The chemical reactions compete with segregation, and the coarsening system settles into a steady-state mesoscale morphology. However, hydrodynamic effects destroy the lamellar morphology which characterizes the diffusive case. This has important consequences for the phase-separating structure, which we study in detail. In particular, the equilibrium length scale (l(eq)) in the steady state suggests a power-law dependence on the reaction rate epsilon : l(eq) similar to epsilon(-theta) with theta similar or equal to 1.0.