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Trace Detection of Dissolved Hydrogen Gas in Oil Using A Palladium Nanowire Array Fan Yang, Dongoh Jung, and Reginald M. Penner* Analytical Chemistry 83 (2011) 9472.  10.1021/ac2021745The prescence of dissolved hydrogen in transformer oil signals its impending failure, so sensors are needed to continously monitor transformer oil for H2. We have evaluated a palladium nanowire array (PdNWA), for this purpose. These PdNWAs were prepared using the lithographically patterned nanowire electrodeposition (LPNE) method. The unprotected PdNWA with its electrical contacts was exposed directly to flowing transformer oil, and the electrical resistance of this array was monitored as the dissolved hydrogen concentration in a flowing oil stream was varied. The presence of dissolved H2 at concentrations down to 2 ppm was thereby detected. |
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Mesoporous Manganese Oxide Nanowires for
High Capacity, High Rate Hybrid Electrical Energy Storage. Wenbo Yan, Talin Ayvazian, Jungyun Kim, Yu Liu, Keith C. Donavan, Wendong Xiang, Yongan Yang, John C. Hemminbger, and Reginald M. Penner* ACS Nano 5 (2011) 8275. 10.1021/nn2029583When MnO2 nanowires are electrodeposited at a high rate using a series of voltage pulses, mesoporous delta-phase MnO2 nanowires are obtained. These "mp-MnO2" nanowires consist of a network of 2-5 nm fibrils, and they have a porosity of 43-56%. Arrays of 20 nm x 400 nm mp-MnO2 nanowires show a super-high specific capacity of 923 F/g at 5 mV/s and 484 F/g at 100 mV/s. |
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Tunable Photoconduction Sensitivity and Bandwidth for Lithographically Patterned Nanocrystalline Cadmium Selenide Nanowires. Sheng-Chin Kung, Wendong Xing, Wytze van der Veer,Fan Yang, Keith Donavan, Ming Cheng, John C. Hemminger, and Reginald M. Penner* ACS Nano 5 (2011) 7627. 10.1021/nn202728fBy adjusting the grain diameter of electrodeposited CdSe nanowires from 5 nm to 100 nm, the photoconductive gain was elevated from G = 0.017 (dave = 5 nm) to 4.9 (100 nm), a factor of 290 and the photocurrent rise time was increased from 8 micros for dave = 10 nm to 8 s for 100 nm, corresponding to a decrease by a factor of 1 million of the photoconduction bandwidth from 44 kHz to 44 mHz. |
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Virus-PEDOT Composite Films for Impedance-Based Biosensing Keith C. Donavan, Jessica A. Arter, Rosa Pilolli, Nicola Cioffi, Gregory A. Weiss*, and Reginald M. Penner* Analytical Chemistry 83 (2011) 2420. 10.1021/ac2000835Electrodeposited films of PEDOT containing M13 virus particles can be used for impedance-based biosensing. The total impedance of this composite film increases when an antibody is selectively bound by the film from aqueous solution. Uniquely, this bioaffinity medium can be electroplated in a single step requiring a minute or two. |
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Enhanced Thermoelectric Metrics in Ultra-Long Electrodeposited PEDOT Nanowires David K. Taggart, Yongan Yang, Sheng-Chin Kung, Theresa M. McIntire and Reginald M. Penner* Nano Letters 11 (2011) 125. 10.1021/nl103003d Nanowires of the conductive polymer PEDOT have a surprisingly large Seebeck coefficient of -122 µV/K - more than twice as high as measured for PEDOT films. |
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© 2011, Reginald M. Penner