Surface-controlled shape design of discotic micro-particles

We demonstrated experimentally and theoretically the principle to control the discotic morphology of particles with a layered internal structure. The packing of surfactants tailored the curvature and set the shape of the elastic membrane produced as the surface of the emulsions crystallized via surface freezing. Using these membranes as the nuclei, emulsions crystallized from the surface to the centre, forming a layered structure. The final shape of the disks could be either biconcave or flat circular depending on the defect structures of the layers. We confirmed that the final aspect ratio of these disks could be controlled by varying co-surfactant concentration on the surface. We also showed that the morphology of anisotropic particles is vital to their self-assembling behaviours. This surface controlled organization of molecules and colloids offers novel routes for soft material design, fabrication, and utilization at micro-scales.