Wei Pan
Tsinghua University, China
Device realization with nanofiber and thin film solid ionic electrolyte materials for low temperature applications
Biography:
Pan is the professor and director of State Key Lab of New Ceramics and Fine Processing of China. He received BS(1982) degree in engineering from the University of Science and Technology Beijing in China, MS(1987) and PhD(1990) degrees in engineering from Nagoya University in Japan. He currently served the member of University Council of Tsinghua University; fellow of School of Engineering of University of Tokyo; member of standing-committee of the Chinese Ceramic Society, and member of the editorial board of several international journals. He is also the member of World Academy of Ceramics. His research interests include low thermal conductive ceramics for gas-turbine, solid-electrolyte, and nano-ceramics.
Abstract:
Timing: 11:15-11:45 CEST
Oxygen sensor assembled using nanofiber and thin film solid electrolyte and applicable at low temperature is presented in this talk. The aim of this study is to fabricate the solid electrolyte based oxygen sensors, monitoring the air-fuel ratio at low temperature to control the emission of exhaust at auto start and/or at low speed running. This presentation reports the preparation of the well oriented zirconia based and ceria based solid electrolyte nanofibers using a specially designed electro spinning device. The conductivity of the oriented nanofibers reached to as high as 0.02 S/cm at 300oC which is two orders of magnitude higher than that of the bulk materials. Micro-oxygen sensor was realized using the oriented nanofibers, and demonstrated good performances. In addition, the multilayer structured solid electrolytes prepared by a magnetron sputtering were also adopted for the fabrication of oxygen sensor. The conductivity of the multilayer electrolyte is highly enhance by the heterostructured interfaces, compared with their bulks. Preparation process of oxygen sensors using the multilayer structured solid electrolyte and the sensor performance is introduced.
Ming-Hwa R Jen
National Sun Yat-Sen University, Taiwan
Fatigue Responses and Mechanical Properties of Single-Edge-Cracked Ti/APC-2 Nanocomposite Laminates with Infinitesimal Kinks
Biography:
Abstract:
Timing: 11:45-12:15 CEST
The mechanical properties and fatigue responses of Ti/APC-2 hybrid nanocomposite laminates of single-edged cracks with the infinitesimal inclined kink angles are investigated. The neat and nanocomposite laminates are fabricated at laboratory with the geometry and dimensions of LxWxt=240.0x25.0x1.55 mm3. The crack length is a constant of 3mm and the kinkangles are 0°, 30°, 45° and 60°. The cracks and kink angles are cut by using electrical wire method.
The original and cracked samples of neat and nanocomposite laminates are due to tensile tests at room temperature to receive theσ-εcurves for original samples and P-Δcurves for cracked samples. The mechanical properties are the base-line data for cyclic tests. An MTS 810 servohydraulic computer controlled dynamic material testing machine is used to conduct the tensile and sinusoidal constant stress amplitude tension-tension fatigue tests with stress ratio R=0.1and frequency=5 Hz. The S-N curves, fatigue lives and failure mechanisms are obtained.
Insteadof 3.0mmcrack, at the tip the kink guides the way of crack propagation. Thus, the mixed mode stress intensity factors such as KI and KII for crack length, and kI and kII for the kink are complicated. Then, the equivalent stress intensity factor range is adopted in the modified Paris Law to predict the fatigue life theoretically. The experimentally measured data will be compared with the results predicted theoretically. Also, the measured lives will be compared with the results of the corresponding samples with inclined single-edge cracks. It is found that the lives obtained in the former samples are less than those of the latter samples. The shorter path from the tip of crack to the free edge is the main reason.
Wei-Lung Tseng
National Sun Yat-sen University, Taiwan
Gold(I)-Thiolate Oligomers for Catalytic Hydrogenation of Nitroaromatics in Aqueous and Organic Medium
Biography:
Wei-Lung Tseng received his PhD. degree from the Department of Chemistry, National Taiwan University in 2002. He is currently a Professor of Chemistry at National Sun Yat-sen University. He began his independent career as a member of the chemistry faculty at National Sun Yet-sen University in 2005. His research group is creating structures on metal nanoparticles and nanoclusters for the development of colorimetric/fluorescent sensors and nanoparticle-related extraction system based molecular recognition and covalent bonding formation. Moreover, he devised a series of oligonucleotide-based sensors for selective and sensitive detection of heavy metal ions, an anti-cancer drug, and single nucleotide polymorphisms.
Abstract:
Timing: 12:15-12:45 CEST
Thiolated gold nanoclusters (AuNCs) have been introduced to efficiently and selectively catalyze the hydrogenation of nitroaromatics due to the strong interaction of their S-Au-S staple motifs with the nitro groups of nitroaromatics. However, gold(I)-thiolate oligomers (AuSOs) with the S-Au-S staple motifs are rarely explored as a catalyst for nitroaromatics. Here, we report a straightforward strategy for the synthesis of the AuSOs through the hydroxyl radical-induced leaching of glutathione-capped gold nanoparticles (GSH-AuNPs). Spectroscopic techniques and transmission electron microscopy confirmed the etching reaction of GSH-AuNPs with hydroxyl radicals. Raman spectroscopy and matrix-assisted laser desorption/ionization-time of flight mass spectrometry demonstrated that hydroxyl radical-triggered etching of the GSH-AuNPs resulted in the production of the AuSOs, including Au4(GSH)7 and Au7(GSH)9. The AuSOs were found to catalyze NaBH4-mediated hydrogenation of 4-nitrophenol to 4-aminophenol with chemoselectivity of ~100% and a normalized rate constant (Knor) of 4.8 ? 105 s-1 g-1. The Knor value of the AuSOs is superior to that of the previously reported materials obtained from more than 100 literature. In addition to the high affinity of the S-Au-S staple motifs with 4-nitrophenol, the unusual catalytic activity of the AuSOs was attributable to the fact that they efficiently catalyzed the production of H2 from NaBH4 and the reaction of dissolved oxygen and NaBH4. The chemoselectivity and applicability of the AuSOs were further verified by performing the catalytic reaction of methyl 2-(2-nitrophenyl) acetate and NaBH4 that resulted in the best yield of 75% oxindole. More interestingly, the AuSO-catalyzed reaction of NaBH4 and methyl 4-nitrobenzoate gave rise to a 100% selectivity and a 100% conversion for methyl 4-aminobenzoate products in polar protic alcohols.