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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 505 records · Page 28
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Topologically guided tuning of Zr-MOF pore structures for highly selective separation of C6 alkane isomers

Effective separation of alkane isomers is a critical step in the petroleum refining process to produce gasoline with high octane rating. Current technology relies on energy intensive distillation method. Adsorptive separation using porous solids offers an alternative route that is more cost effective, lower energy and higher efficiency. Guided by topology-directed design and synthesis, we have developed a series of zirconium-based metal-organic frameworks with optimized pore structure for efficient separation of C6 alkane isomers, Zr-bptc adsorbs a large amount of n-hexane while excluding branched isomers. The n-hexane uptake is ~70% higher than that of a benchmark adsorbent, zeolite-5A. A derivative structure, Zr-abtc, is capable of discriminating all three C6 isomers with a high separation factor for 3-methylpentane over 2,3-dimethylbutane. This property is important for producing gasoline with further improved quality.

36 MATERIALS SCIENCE↗
DOE OSTI2013

Towards the selective modification of soft-templated mesoporous carbon materials by elemental fluorine for energy storage devices

Graphite fluoride is classified into (CF) n and (C 2 F) n types based on its structure and composition. In the former (CF) n has been widely prepared and commercially utilized as electrodes in primary lithium ion batteries (LIBs). Porous electrodes, i.e. templated mesoporous carbons, can greatly improve first Coulombic efficiencies. Furthermore, by achieving the highest discharge potentials and rate capabilities, the extent of fluorination reactions and the retention of a conductive carbon backbone are required. Thus, the choice of the starting carbon nanomaterial and of the fluorination conditions is detrimental to the design of future energy storage and conversion devices, namely LIBs and pseudosupercapacitors.

25 ENERGY STORAGE↗
DOE OSTI2012

Frequency-selective plasmonic wave propagation through the overmoded waveguide with photonic-band-gap slab arrays

Confined propagation of guided waves through the periodically corrugated channel sandwiched between two staggered dielectric photonic-band-gap slab arrays is investigated with the band-response analysis. Numerical simulations show that longitudinally polarized evanescent waves within the band gap propagate with insertion loss of {approx}-0.2 to 1 dB (-0.05 to 0.4 dB/mm at G-band) in the hybrid band filter. This structure significantly suppresses low energy modes and higher-order-modes beyond the band-gap, including background noises, down to {approx}-45 dB. This would enable the single-mode propagation in the heavily over-moded waveguide (TEM-type), minimizing abnormal excitation probability of trapped modes. This band filter could be integrated with active and passive RF components for electron beam and optoelectronic devices.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗