排序方式: 共有96条查询结果,搜索用时 0 毫秒
91.
Tour JM Cheng L Nackashi DP Yao Y Flatt AK St Angelo SK Mallouk TE Franzon PD 《Journal of the American Chemical Society》2003,125(43):13279-13283
NanoCells are disordered arrays of metallic islands that are interlinked with molecules between micrometer-sized metallic input/output leads. In the past, simulations had been conducted showing that the NanoCells may function as both memory and logic devices that are programmable postfabrication. Reported here is the first assembly of a NanoCell with disordered arrays of molecules and Au islands. The assembled NanoCells exhibit reproducible switching behavior and two types of memory effects at room temperature. The switch-type memory is characteristic of a destructive read, while the conductivity-type memory features a nondestructive read. Both types of memory effects are stable for more than a week at room temperature, and bit level ratios (0:1) of the conductivity-type memory have been observed to be as high as 10(4):1 and reaching 10(6):1 upon ozone treatment, which likely destroys extraneous leakage pathways. Both molecular electronic and nanofilamentary metal switching mechanisms have been considered, though the evidence points more strongly toward the latter. The approach here demonstrates the efficacy of a disordered nanoscale array for high-yielding switching and memory while mitigating the arduous task of nanoscale patterning. 相似文献
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93.
Hydrazine fuels for bimetallic catalytic microfluidic pumping 总被引:1,自引:0,他引:1
Ibele ME Wang Y Kline TR Mallouk TE Sen A 《Journal of the American Chemical Society》2007,129(25):7762-7763
94.
Wang Y Hernandez RM Bartlett DJ Bingham JM Kline TR Sen A Mallouk TE 《Langmuir : the ACS journal of surfaces and colloids》2006,22(25):10451-10456
Bimetallic nanorods are propelled in aqueous solutions by the catalytic decomposition of hydrogen peroxide to oxygen and water. Several mechanisms (interfacial tension gradients, bubble recoil, viscous Brownian ratchet, self-electrophoresis) have been proposed for the transduction of chemical to mechanical energy in this system. From Tafel plots of anodic and cathodic hydrogen peroxide reactions at various metal (Au, Pt, Rh, Ni, Ru, and Pd) ultramicroelectrodes, we determine the potential at which the anodic and cathodic reaction rates are equal for each metal. These measurements allow one to predict the direction of motion of all possible bimetallic combinations according to the bipolar electrochemical (or self-electrophoretic) mechanism. These predictions are consistent with the observed direction of motion in all cases studied, providing strong support for the mechanism. We also find that segmented nanorods with one Au end and one poly(pyrrole) end containing catalase, an enzyme that decomposes hydrogen peroxide nonelectrochemically, perform the overall catalytic reaction at a rate similar to that of nanorods containing Au and Pt segments. However, in this case there is no observed axial movement, again supporting the bipolar electrochemical propulsion mechanism for bimetallic nanorods. 相似文献
95.
Ramnarayanan R Chan BC Salvitti MA Mallouk TE Falih FM Davis J Galloway DB Bare SR Willis RR 《Journal of combinatorial chemistry》2006,8(2):199-212
The synthesis and analysis of inorganic material combinatorial libraries by a directed-sorting, split-pool bead method was demonstrated. Directed-sorting, split-pool, metal-loaded libraries were synthesized by adsorbing metal salts (H2PtCl6, SnCl2, CuCl2, and NiCl2) and metal standards (Pt, Cu, Ni in HCl) onto 2-mg porous gamma-alumina beads in 96- or 384-well plates. A matrix algorithm for the synthesis of bead libraries treated each bead as a member of a row or column of a given matrix. Computer simulations and manual tracking of the sorting process were used to assess library diversity. The bead compositions were analyzed by energy-dispersive X-ray spectroscopy, X-ray fluorescence spectroscopy, electron probe microanalysis, inductively coupled plasma atomic emission spectroscopy, and inductively coupled plasma mass spectroscopy. The metal-loaded beads were analyzed by laser-activated membrane introduction mass spectroscopy (LAMIMS) for catalytic activity using methylcyclohexane dehydrogenation to toluene as a probe reaction. The catalytic activity of individual beads that showed minimal (approximately 20% of that of Pt on alumina) to high conversion could be determined semiquantitatively by LAMIMS. This method, therefore, provides an alternative to screening using microreactors for reactors that employ catalysts in the form of beads. The directed-sorting method offers the potential for synthesis of focused libraries of inorganic materials through relatively simple benchtop split-pool chemistry. 相似文献
96.
Benbellat N Gavrilenko KS Le Gal Y Cador O Golhen S Gouasmia A Fabre JM Ouahab L 《Inorganic chemistry》2006,45(26):10440-10442
A new trimethyltetrathiafulvalene (Me3TTF) derivative Me3TTF-CH=CH-py bearing a pyridyl was synthesized and coordinated to a cobalt(II) benzoate dimer, having paddlewheel core structure, leading to a complex formulated as Co2(PhCOO)4(Me3TTF-CH=CH-py)2. Single-crystal X-ray diffraction studies of the complex performed at 293 and 100 K evidenced the existence of a weak metal-metal interaction. Magnetic studies revealed an antiferromagnetic behavior, which is explained as the result of the direct exchange between metal centers. 相似文献