Jülich Soft Matter Days 2009 location:Bonn, Germany date:10-13 November 2009
Anisotropic nanoparticles are being increasingly used in many applications. Presently, dimensions of nanoparticles are mainly obtained by transmission electron
microscopy (TEM). The average dimensions from TEM are obtained by image analysis of a few hundred particles, resulting in poor statistical average. Also, microscopy
does not provide any information on the hydrodynamic dimensions. For studies of dynamical properties such as sedimentation or rheology, hydrodynamic dimensions of
the particle are more important than the actual physical dimensions. In the present work, a rheo-optical technique (dichroism) is used, which gives a faster and better
statistical average of the hydrodynamic aspect ratio and the associated polydispersity. Results obtained from dichroism for stiff gold rods and gold decahedrons will be
presented. Results for gold rods will be compared to those obtained from TEM and dynamic light scattering (DLS).