Spectroscopic Visualization of Vortex Flows Using Dye‐Containing Nanofibers

Abstract

Which way around? A J-aggregated zinc porphyrin dendrimer can be used to detect the macroscopic chirality of a vortex. The sign of the circular dichroism response changes quickly upon switching from clockwise (CW) to counterclockwise (CCW) stirring (see picture). The observed chiroptical activity most likely arises from a macroscopic helical alignment of nanofibers formed from the polymeric J-aggregate.