Speaker: Professor Zhihong Nie, Department of Chemistry and Biochemistry University of Maryland, College Park Title: Liquid Crystal Behaviors of Colloidal Particles
Abstract: Colloidal particles can assemble into new functional materials with diverse applications in, such as coating, photonics/phononics, sensing, and metamaterials. Moreover, they can often be directly visualized under an optical microscope, owing to their unique dimension (from hundreds of nanometers to micrometer scale). This makes them ideal models for studying the assembly or phase behavior of atoms and molecules that are otherwise not easy to observe directly. For instance, spherical colloids are frequently used to understand the packing and dynamics of atoms. To gain new insight into the interaction and assembly of molecules in general, colloidal particles with nonspherical shapes (e.g., platelets, bowls, and rods) are required, given the geometric diversity of organic molecules. However, currently available colloidal analogues of organic molecules are largely limited to spheres, platelets, bowls, or cylindrical rods because of existing synthetic challenges. In this talk, I will present our efforts on the wet-chemical synthesis of nonconventional colloidal particles (e.g., banana-shaped rods, boardlike plates, dumbbell-like particles, etc.) and the exploitation of their assembly into a variety of mesophaes that are often observed in organic liquid crystal molecules (e.g., banana-shaped mesogens).