SPINODAL DECOMPOSITION UNDER SHEAR-FLOW

The spinodal decomposition of a two-dimensional model binary fluid und ergoing planar Couette flow has been studied by molecular dynamics sim ulation. The effect of the strength of the shear field on the growth o f the domains was analyzed. The main effect of the shear field is the deformation of the domains which results in anisotropic structure deve lopments. We have characterized these anisotropic structures by measur ing the domain size in two different directions, the direction of the flow and the direction of the shear. We find that the dependence of th e deformation of the domains on the strain applied to the system shows the same behavior as found in experiments. Moreover, we find that the shear flow can enhance the domain growth in the direction of the flow and it can restrain and even suppress this growth in the direction no rmal to the flow. The influence of the morphology on rheological prope rties was also analyzed. We find that viscosity depends on the quench time and the shear field, and is caused by the extension and direction of the interfacial area. (C) 1997 American Institute of Physics.