Electrical Engineering Seminar

Friday April 12, 2019 12:00 PM

Chiral Inorganic Nanostructures: Why, How, and So What.

Speaker: Nicholas Kotov, Department of Chemical Engineering, University of Michigan, Ann Arbor
Location: Moore B270

Pizza lunch will be provided @ 11:45am

ABSTRACT Early observation of strong circular dichroism for individual nanoparticles (NPs) and their assemblies have developed into a rapidly expanding field of chiral inorganic nanostructures. They currently include sophisticated nano-constructs from metals, semiconductors, ceramics, and nanocarbons with multiple chiral geometries with characteristic scales from Ångströms to microns. Many of them are formed spontaneously from polydispersed building blocks (Fig. 1), which enables their structural and functional engineering over a broad range geometries and optical properties. This talk will address (1) the mechanisms of chirality transfer in inorganic materials, (2) the origin of the uniquely high values of optical anisotropy, (3) the fundamental challenges of multiscale chirality observed in nanostructures, and (4) physicochemical differences/similarities with chiral supramolecular, liquid crystal, and biological systems. The analysis of phase diagrams for the assembly of chiral NPs affords understanding essential role of critical phenomena in the assembly at nanoscale that can lead to exceptionally complex assemblies from polydispersed nanocomponents exemplified by chiral hedgehog particles. The parallels with biomineralized skeletons of coccoliths help understanding the need for chiral asymmetry in live matter. Simplification of the chiral assembly processes also helps accelerating the development of technologies based on chiroplasmonic, chiroexcitonic, and chiromagnetic effects observed for the individual NPs and their assemblies.

BIO Prof. Nicholas A. Kotov is working on conceptual foundations and technical realizations of biomimetic nanostructures. In the course of his studies he demonstrated that self-organization is the unifying property of all nanoscale matter. Examples of biomimetic nanostructures associated with his works include graphite oxide,- graphene- and clay-based layered biomimetic nanocomposites, chiral nanomaterials, and omnidispersible colloids. His contribution to technology include ultrastrong nacre-mimetic nanocomposites, soft neuroprosthetic implants, 3D tissue replicas for drug-testing, chiral biosensors, and cartilage-like electrolytes for batteries. Prof. Kotov is a founder of several start-up companies that commercialized bioinspired nanomaterials for biomedical, energy, and automotive technologies.

Series Electrical Engineering Seminar Series

Contact: Liliana Chavarria at 626-395-4715 lchavarr@caltech.edu