We report on the behavior of colloidal spheres suspended in nematic solutions of rodlike (calamitic phase) and disklike (discotic phase) micelles. The particles form anisotropic structures that depend on the shape of the surrounding micelles. An analysis of these structures indicates that dipolar and quadrupolar elastic interactions are, respectively, observed in discotic and calamitic nematics. This shape dependency can be understood by considering the entropy driven alignment of the micelles at the surface of the particles.

• Received 21 September 1998

DOI:https://doi.org/10.1103/PhysRevE.59.4384