DIRECT VISUALIZATION OF INDIVIDUAL CYLINDRICAL AND SPHERICAL SUPRAMOLECULAR DENDRIMERS

Electron microscopy methods have been used to visualize individual sph erical and cylindrical supramolecular dendrimers, providing definitive confirmation of the structures suggested by previous x-ray diffractio n analysis that assumed a microsegregated model. These dendrimers are self-assembled, self-organized, and aligned spontaneously and simultan eously in hexagonal columnar or cubic thermotropic liquid-crystal phas es with high uniformity. Homeotropic and planar ordering of the hexago nal columnar liquid crystal was precisely controlled by a variety of s urfaces. The stiffness of these cylinders was evaluated by examining t heir planar texture and its defects.