The alignment of silver nanowires due to the ionic surfactant

The evaporation process of complex fluid usually accompanies the emergence of the strong internal flow effect, which changes the deposition pattern. In this experiment, we coat a substrate with a solution of mixture of silver nanowire, water, and ionic surfactant. The solution is dried by heating the substrate, and we visually inspect the drying pattern of the silver nanowire. We find that when the surfactant concentration is relatively low, the drying pattern is isotropic, but when the surfactant concentration is large enough, the pattern becomes anisotropic.