Title: A General and Robust Strategy for Monodisperse Nanocrystals by Capitalizing on Amphiphilic Unimolecular Star-Like Block Copolymers as Nanoreactors

Speaker: Zhiqun Lin, School of Materials Science and Engineering, Georgia Institute of Technology

Time: 10:00 a.m., June 21, 2013

Venue: Conference Room 205, Building 14, SCUT North Campus

Sponsor: School of Materials Science and Engineering

Abstract: Colloidal nanocrystals exhibit a wide range of size and shape dependent properties and have found application in a myriad of fields such as optics, electronics, mechanics, drug delivery and catalysis to name but a few.  Synthetic protocols that enable simple and convenient production of colloidal nanocrystals with controlled size, shape and composition are therefore of key general importance. Current strategies, however, often require stringent experimental conditions, are difficult to generalize, or require tedious multi-step reactions and purification. Recently, linear amphiphilic block copolymer micelles have been used as template for the synthesis of functional nanocrystals, but the thermodynamic instability of these micelles limits the scope of this approach. In this talk, I will elaborate a general strategy for synthesizing a large variety of functional nanocrystals with precisely controlled dimensions, compositions and architectures by using star-like block copolymers as templates. This new class of copolymers forms unimolecular micelles that are structurally stable under various experimental conditions and therefore overcomes the intrinsic instability of linear block copolymer micelles. Our approach enables the facile synthesis of organic solvent- and water-soluble nearly monodisperse nanocrystals with desired composition and architecture, including core/shell and hollow nanostructures. To demonstrate the generality of our approach we describe, as examples, the synthesis of various sizes and architectures of metallic, semiconductor, ferroelectric, magnetic and luminescent colloidal nanocrystals.

Introduction to Associate Prof. Zhiqun Lin: Dr. Zhiqun Lin is an Associate Professor at the School of Materials Science and Engineering at the Georgia Institute of Technology. He received his BS degree in Chemistry from Xiamen University in 1995, MS degree in Macromolecular Science from Fudan University in 1998, and PhD degree in Polymer Science and Engineering from University of Massachusetts, Amherst in 2002. He was a postdoctoral associate at UIUC. He joined the Department of Materials Science and Engineering at the Iowa State University in 2004 and was promoted to Associate Professor in 2010. He moved to Georgia Institute of Technology in 2011. His research interests include polymer-based nanocomposites, block copolymers, polymer blends, conjugated polymers, quantum dots (rods, tetrapods and wires), functional nanocrystals (metallic, magnetic, semiconducting, ferroelectric, multiferroic, upconversion and thermoelectric) of different architectures (plain, core/shell, hollow and Janus), solar cells (organic-inorganic hybrid solar cells and dye sensitized solar cells), hierarchically structured and assembled materials, and surface and interfacial properties. He has published 120 peer reviewed journal articles (with an h-index of 33 and a total citation of 3716), 4 book chapters, and 1 book. Currently, he serves as an Associate Editor for Journal of Materials Chemistry A, and an editorial advisory board member for Nanoscale. He is a recipient of Frank J. Padden Jr. Award in Polymer Physics from American Physical Society, an NSF Career Award, a 3 M Non-Tenured Faculty Award, and an invited participant at the National Academy of Engineering’s 2010 US Frontiers of Engineering Symposium. More information on his research can be found at http://nanofm.mse.gatech.edu/.