Uncovering Log Jamming in Semidilute Suspensions of Quasi-Ideal Rods

Video microscopy of fluorescently labeled semiflexible, slender, monodisperse colloidal rods in a host dispersion of unlabeled rods reveals a complex skating-type motion. Trajectories of single rods consist of a zig–zag sequence of paths where rods move within a tube set up by the surrounding rods. We show that head-on collisions within the tube affect the dynamics in a fundamental way, leading to a unique anomalous splitting of the distribution of particle displacements. Based on this log jamming process and relatively weak tube confinement, we propose an improved coupling relation between the parallel and perpendicular motion of individual rods within a tube.