【16th June】 Single Nano-device Design and In-situ TEM Study
日期：2015-06-16
閱讀：878
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TITLE： Single Nano-device Design and In-situ TEM Study
SPEAKER： Prof. Junjie Niu, University of Wisconsin-Milwaukee, USA
TIME：June 16 (Tuesday) AM10:00
LOCATION： 410 Meeting Room， Chemistry Building B (化學(xué)B樓410會(huì)議室)
INVITER ： 馬紫峰教授，李磊副研究員
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Nano-devices using varying nano-structured materials are investigated. In particular, the gold nanoparticle-decorated single carbon nanotube (CNT) tipped probe is used to study intracellular environments in situ using surface-enhanced Raman spectroscopy (SERS) (Nat Nanotechnol 6 2011 57). The decorated CNT was assembled onto the tips of pulled glass capillaries to form a SERS-enabled endoscope. The high mechanical strength of the nano-scale endoscope made it possible to penetrate the cell membrane for intracellular probing without causing damage to the cell (Small 7 2011 540). The SERS-enabled endoscopes exhibited high selectivity and sensitivity for detecting trace amounts of analytes in bio-fluid environments, highlighting its capabilities in areas that necessitate minimally invasive intra-cellular detection, drug delivery, single-cell surgery, and label-free biological sensors.
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In-situ HRTEM study of LiFePO4 nanowire delithiation kinetics at atomistic scale will also be presented. Real-time observed 20nm solid solution (SS) contains no dislocations, so coherency stress accelerates Li+/e- transport. Large SS with a boundary could dominate the phase transformation at non-equilibrium condition; for larger particles, SS provides out-of-equilibrium but atomically wide avenues for Li+/e- transport (Nano Lett 2014).
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Biography
Dr. Junjie Niu is an Assistant Professor in Department of Materials Science and Engineering at University of Wisconsin-Milwaukee. He received Ph.D. in Materials Science from Zhejiang University in 2005. From 2005 to 2009, he was a faculty at Shanghai JiaoTong University before joining Prof. Yury Gogotsi group at Drexel as a Postdoc. From 2011, he moved to Prof. Ju Li group at UPenn and MIT, developing a new lab and leading the experimental research. Dr.Niu’s interdisciplinary research includes understanding fundamental science in physics/chemistry, and engineering nanomaterials in applications of energy storage, biomaterials and chemo-mechanics.
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