Speaker:  Dr. Qingwen Li
Time: 10:00 a.m, Jan. 10, 2012 (Tuesday)
Location:  Room 215, School of Materials Science and Engineering (MSE)
 
Abstract:
Carbon nanotubes (CNTs) are the strongest material ever synthesized by mankind.  It has extremely high tensile strength (>60 GPa), high modulus (1 TPa), large aspect ratio (104 to >106), low density (less than 1.4 g/cm3), good chemical and environmental stability, high thermal conductivity (better than diamond) and relatively good electrical conductivity. These unique properties make CNTs very attractive not only for the fabrication of nanoscale devices, but also for broad potential applications in macroscale, such as strong fibers for body armors and light-weight aerospace structures, and electronic fibers for smart textiles. In my talk, I will summarize our recent efforts on how to assemble nanoscale individual tubes into macroscale fibers with high strength and multifuntionalities in the following four aspects: 1) the mechanical strength of individual tubes; 2) the self-assembly of carbon nanotubes; 3) solid-state spinning of carbon nanotube fibers; 4) ultimate carbon fibers and application prospects. Material synthesis is the key issue for practical applications of nanoscience and nanotechnology. The chemical composition, size, morphology and phase of the materials determine the chemical and physical properties of materials themselves. Our research focuses on the rational design and nanoscale integration of highly complex nanostructures through chemical synthesis and/or physical assembly. A strong emphasis is placed on the hetero-integration of multi-composition, multi-structure and multi-function at nanoscale, with an aim to create a new generation of integrated nanosystems with unique functions or unprecedented performances that can break the boundaries of traditional technologies. In this seminar, I will discuss the approaches towards the successful material synthesis and their applications in the fields of solar energy conversion, nanodevices, fine organic synthesis and biology.  Several examples including hetero-integrate a nanoscale photovoltaic devices, 1D porous semiconductor nanowires and several nanostructures will be presented.

Introduction to the speaker:

Dr. Qingwen Li got her M.S. and PhD in physical chemistry in 1990 and 2000 from Shandong University and Tsinghua University, respectively. She has been working with carbon nanotube since she joined Prof. Zhongfan Liu’s gourp as a postdoc in 2001. Her interests include carbon nanotube controllable growth, surface modification and application development. She once worked with Prof. Alan Windle in University of Cambridge from 2003 to 2005 on wet-processing of carbon nanotubes, and Dr. Y. T. Zhu at Los Alamos national laboratory from Mar. 2005 to Dec. 2007 on growing ultralong carbon nanotube arrays and spinning strong carbon nanotube fibers.  She joined Suzhou Institute of Nano-tech and Nano-bionics at the end of 2007, as a professor of “hundred talent project” supported by Chinese Academy of Science. She has published over 50 peer reviewed journal articles and applied 5 American and 10 Chinese patents. Dr. Li has won the Nano 50TM and Micro 25 awards in 2007 (US) and also award of excellence by Los Alamos National lab.  Dr. Li's current research focus is on the development and applications of carbon nanotube based composites.