Directional Brownian diffusion dynamics with variable magnitudes

The coupling effects of rotational and translational Brownian motion in anisotropic macromolecules result in differentiated diffusion constants parallel and perpendicular to the particle's long axis in the short term. Investigations of these dynamics allow for a greater understanding of how directional alignment can be harnessed for applications. We investigate the dynamics using carbon nanofibers here and the results infer that significant reduction in the diffusion constants can result from probable hydrodynamic interactions. The diffusion constant perpendicular to the particle's long axis is particularly reduced. (C) 2008 American Institute of Physics.