Permeability and conductivity of platelet-reinforced membranes and composites

We present large-scale simulations of the diffusion constant D of a random composite consisting of aligned platelets with aspect ratio a/b>>1 in a matrix (with diffusion constant D0) and find that D/D(0)=1/(1+c(1)x+c(2)x(2)), where x=av(f)/b and v(f) is the platelet volume fraction. We demonstrate that for large aspect ratio platelets the pair term (x(2)) dominates suggesting large property enhancements for these materials. However, a small amount of face-to-face ordering of the platelets markedly degrades the efficiency of platelet reinforcement.