[责任编辑]李敏妍 [信息提供]化工学院
报告题目：Developing Active Nanostructures
报告人：陈虹宇教授，南洋理工大学
报告时间：12月19日（周三）上午10:00
报告地点：化学楼演讲厅
邀请人：车顺爱教授（化学化工学院）
About the speaker:
陈虹宇博士是南洋理工大学化学与生物化学系的副教授。他1998年从中国科技大学应用化学系学士毕业，2004年从耶鲁大学取得博士学位，然后在康乃尔大学做了一年半的博士后。自2006年10月起在南洋理工大学工作， 2011年3月任副教授。
Hongyu Chen obtained his B. Sc. from University of Science and Technology of China (USTC) in 1998 under Prof. Yitai Qian. He then moved to Yale University and studied Mn and water oxidation chemistry under the joint supervision of Prof. Gary W. Brudvig and Robert H. Crabtree. After obtaining his Ph.D. degree in 2004, he worked as a post-doctoral fellow with Prof. Carl A. Batt in Cornell University on the topic of protein-nanoparticle hybrids. In 2006, he joined the Division of Chemistry and Biological Chemistry in Nanyang Technological University in Singapore, where he is currently an Associate Professor. His main research interest is in the development of new synthetic methodologies for nanostructures.
Abstract:
The talk will consist of two parts. I will start with our recent work on silica and yolk-shell structures. The sequential hydrolysis of TEOS probably leads to inhomogeneous composition in the resulting silica shells. Such inhomogeneity can be exploited for facile synthesis of multi-layer yolk-shell motives. In the second part, I will discuss our recent progress on active nanostructures, that is, colloid nanostructures that can undergo predictable conformational changes in solution. Our aim is to induce motion that is not passive and not random. We demonstrate the controllable coiling of colloidal gold nanowires induced by the contraction of their polymer shells. The mechanical energy stored in this process can be released upon removal or swelling of the polymer shells. With some modification in the methods, we showed that bundles of carbon nanotubes can also be coiled into ring structures by controlling the contraction of their polymer shells. With the robust carbon nanotubes, we further demonstrated their reversible transformation in a colloidal solution between circular and compressed rings. Most recently, we showed that ultrathin nanowires made of Au-Ag alloy can wind around themselves to form double helices upon growth of an additional metal layer. The detailed mechanisms of these systems will be discussed.
