Giant Molecules Based on ‘Nano-Atoms’: A New Platform for Engineering Structures at Nanometer Feature Sizes

Event Date: December 5, 2013
Speaker: Prof. Stephen Z. Cheng
Speaker Affiliation: College of Polymer Science and Polymer Engr.
University of Akron
Time: 9:00 - 10:15
Location: FRNY G140
Priority: No

Abstract:  To create new materials with multiple functionalities for advanced technologies, control over their hierarchical structures and orders is vital for obtaining the desired properties. Our research focuses on a new route to build up materials via giant molecules based on “nano-atoms”. We utilize molecular nano-particles (MNPs) to be the basic unit for “nano-atoms” which are compact and rigid, possess precisely-defined symmetry and surface functionalities. These NMPs may be polyhedral oligomeric silsesquioxane (POSS), [60]fullerene (C60), polyoxymatalates, and globular proteins. With the help of those accurately-defined surface functionalities to generate collective physical bonds to construct giant molecules which are precisely defined macromolecules. Giant molecules include shape amphiphiles, giant polyhedra and giant surfactants etc. While these particles share some common features, they are intrinsically different in many ways, such as the overall shape, physical properties, and chemical composition. By diverse periphery functionalization, they serve as versatile “nano-atoms” for the construction of giant molecules with controlled hierarchical structures in multi-dimensions across different length scales. A large variety of thermodynamically stable and metastable hierarchal structures is observed in the bulk, thin-film, and solution states of these “giant molecules”. All the results demonstrate that MNPs are unique elements for macromolecular science, providing a versatile platform for engineering nanostructures that are not only scientifically intriguing, but also technologically relevant.