String Phase in Phase-Separating Fluids under Shear Flow

Transmission light micrographs show that domains in spinodal decomposition are elongated into extremely long strings in steady states of a polymer solution under strong shear flow. The shear flow stabilizes the string against their intrinsic surface tension instabilities. The string diameter decreases with increase in the shear rate and ultimately becomes of the order of the interface thickness, resulting in shear-induced homogenization.