力学系与湍流国家重点实验室学术报告8.25上午( 报告人：Dr.Yu Qiao)
发布时间: 2010-08-18 11:45:00
SEMINAR SERIES
北京大学工学院 
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力学与空天技术系
湍流与复杂系统国家重点实验室
题目：Nanoporous-Materials-Functionalized (NMF) Liquids: Next-Generation Materials for Protection, Actuation, and Energy Harvesting
Dr. Yu Qiao
Department of Structural Engineering & Program of Materials Science and Engineering,
University of California, San Diego (Email: yqiao（at）ucsd.edu )
Abstract: A nanoporous-materials-functionalized (NMF) liquid is a liquid or gel suspension of nanoporous particles. Its main characteristics include: (1) the unique solid-liquid hybrid structure assures the full utilization of the large nanopore surface (100-2000 m2/g), and (2) the multiple energy conversion paths among mechanical, thermal and electric domains.
For instance, if the nanopore surface is hydrophobic, when the liquid phase is forced into the nanopores by an external pressure, mechanical work is dissipated as interfacial tension and heat. As the wettability of nanopore surface is controlled thermally or electrically, self-actuation can be achieved. Electricity is generated as excess counter charges are induced at nanopore surfaces by ions in confined liquid. All of these effects, which may be trivial at a large solid-liquid interface, can be promoted by the large nanopore surface area by a few orders of magnitude.
While nanoporous materials have been widely applied in chemical engineering areas for catalysis, hydrogen storage, and separation and purification, using them for mechano-thermo-electric energy conversion is a new concept. Our study has shown that continuum theory breaks down in the nanoenvironment. Many concepts, such as solubility and surface tension, need to be re-investigated.
Biosketch: Dr. Yu Qiao graduated from the University of Science and Technology of China in 1994 with a B.S. degree in Applied Mechanics. He obtained his M.S. degree in Materials Science in 1997 from the Lab of Nonlinear Mechanics, Institute of Mechanics, and his Ph.D. degree in Mechanical Engineering from the Massachusetts Institute of Technology in 2002. From 2002 to 2006, he was an assistant professor in the University of Akron. In 2006, he jointed the University of California, San Diego as an associate professor. Dr. Qiao's research focuses on advanced energy absorption materials and structures, smart materials and structures, energy conversion techniques, as well as failure analysis of engineering materials. He has more than 100 publications in peer-reviewed journals including J. Am. Chem. Soc., Phys. Rev. Lett., Nano Lett., Langmuir, etc.
主持人：段慧玲 特聘研究员
时 间：8月25日（周三）上午10:00--11:30
地 点：力学楼434会议室
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