ChBE Seminar Series: Controllable and Predictable Synthesis of Colloidal Metal Nanocrystals
Speaker: Younan Xia, Professor, Brock Family Chair, and GRA Eminent Scholar in Nanomedicine at Georgia Institute of Technology
Title: Controllable and Predictable Synthesis of Colloidal Metal Nanocrystals
Recent studies suggest that reduction kinetics play an important role in determining the outcome of a colloidal synthesis of metal nanocrystals. The reduction rate not only controls the internal defect structure, including single-crystal, singly-twinned, multiply-twinned, and stacking-fault lined, of a seed formed in the nucleation step but also dictates the growth pattern (symmetric vs. asymmetric) or mode (island vs. layer-by-layer) of the seed in the following steps. In this talk, I will start with a brief introduction to our recent success in quantifying the kinetic parameters, including the rate constants and activation energies, for a number of systems and then illustrate how this knowledge can be applied to deepen our understanding of the nucleation and growth processes, moving towards the ultimate goal of achieving deterministic and predictable synthesis, together with an easy and quantitative control. The quantitative measure and control allow us to precisely and reproducibly tailor the properties of colloidal metal nanocrystals for a broad range of applications in catalysis, photonics, electronics, energy conversion, sensing, imaging, and biomedicine.
Dr. Xia is the Brock Family Chair and Georgia Research Alliance (GRA) Eminent Scholar in Nanomedicine at the Georgia Institute of Technology. He received a B.S. degree in chemical physics from the University of Science and Technology of China in 1987, a M.S. degree in inorganic chemistry from University of Pennsylvania (with Professor Alan G. MacDiarmid) in 1993, and a Ph.D. degree in physical chemistry from Harvard University (with Professor George M. Whitesides) in 1996. His group has invented a myriad of nanomaterials with well-controlled properties and these nanomaterials have found widespread use in applications related to plasmonics, electronics, photonics, photovoltaics, display, catalysis, fuel cells, nanomedicine, and regenerative medicine. For example, the silver nanowires invented by his group are commercially used in the manufacturing of flexible, transparent, and conductive coatings for applications related to touchscreen, flexible electronics, and photovoltaics. The gold nanocages invented by his group are helping advance cancer theranostics. Xia has co-authored more than 780 publications in peer-reviewed journals, together with a total citation of more than 146,000 and an h-index of 193. He has been named a Top 10 Chemist and Materials Scientist based on the number of citation per publication. He has received a number of prestigious awards, including Materials Research Society (MRS) Metal (2017), American Chemical Society (ACS) National Award in the Chemistry of Materials (2013), NIH Director's Pioneer Award (2006), David and Lucile Packard Fellow in Science and Engineering (2000), NSF CAREER (2000). More information can be found at http://www.nanocages.com.