Self-diffusion of rod-like viruses in the nematic phaseM. P. Lettinga1, E. Barry2 and Z. Dogic2
1 IFF, Institut Weiche Materie, Forschungszentrum Jülich - D-52425 Jülich, Germany
2 Rowland Institute at Harvard, Harvard University - Cambridge, MA 02142, USA
received 21 March 2005; accepted 17 June 2005
published online 22 July 2005
We measure the self-diffusion of colloidal rod-like virus fd in an isotropic and nematic phase. A low-volume fraction of viruses are labelled with a fluorescent dye and dissolved in a background of unlabelled rods. The trajectories of individual rods are visualized using fluorescence microscopy from which the diffusion constant is extracted. The diffusion parallel ( ) and perpendicular () to the nematic director is measured. The ratio ( ) increases monotonically with increasing virus concentration. Crossing the isotropic-nematic phase boundary results in increase of and decrease of when compared to the diffusion in the isotropic phase ( ).
82.70.-y - Disperse systems; complex fluids.
61.30.-v - Liquid crystals.
66.10.-x - Diffusion and ionic conduction in liquids.
© EDP Sciences 2005