A5091045789- Advanced Battery Materials and Technologies
- Advancements in Battery Materials
- Advanced Battery Technologies Research
- Molecular Junctions and Nanostructures
- Organic Electronics and Photovoltaics
- Organic Light-Emitting Diodes Research
- Electrocatalysts for Energy Conversion
- Organometallic Complex Synthesis and Catalysis
- Luminescence and Fluorescent Materials
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Thermodynamic and Exergetic Analyses of Power and Cooling Systems
- CO2 Reduction Techniques and Catalysts
- Nanofabrication and Lithography Techniques
- Force Microscopy Techniques and Applications
- Magnetism in coordination complexes
- Inorganic Fluorides and Related Compounds
- Catalytic Processes in Materials Science
- Fuel Cells and Related Materials
- Conducting polymers and applications
- Advanced Thermodynamics and Statistical Mechanics
- Advanced Thermodynamic Systems and Engines
- Ionic liquids properties and applications
- Analytical Chemistry and Chromatography
- Synthesis and characterization of novel inorganic/organometallic compounds
California Institute of Technology
2015-2022
Jet Propulsion Laboratory
2015-2021
PV3 Technologies (United Kingdom)
2020-2021
Pasadena City College
2019
HiETA Technologies (United Kingdom)
2016-2018
University College London
2017
University of Oxford
1999-2016
Science Oxford
2014
Georgia Institute of Technology
2004-2013
University of Arizona
2002-2010
Phosphonic acids act as robust surface modifiers on barium titanate (BT) nanoparticles (NPs) (see figure), affording homogeneous, high-volume-fraction composites of such NPs in polymeric hosts by simple solution processing. Pentafluorobenzyl phosphonic acid-modified BT nanocomposite films poly(vinylidenefluoride-co-hexafluoropropylene) show large relative permittivities and unusually high dielectric breakdown strengths. Supporting information for this article is available the WWW under...
Transparent metal oxides, in particular, indium tin oxide (ITO), are critical transparent contact materials for applications next-generation organic electronics, including light emitting diodes (OLEDs) and photovoltaics (OPVs). Understanding controlling the surface properties of ITO allows molecular engineering ITO–organic interface, resulting fine control interfacial chemistries electronics. In both energy matching work function compatibility at material interfaces can result marked...
Working toward fluoride batteries Owing to the low atomic weight of fluorine, rechargeable fluoride-based could offer very high energy density. However, current need operate at temperatures that are required for molten salt electrolytes. Davis et al. push can room temperature, through two advances. One is development a room-temperature liquid electrolyte based on stable tetraalkylammonium salt–fluorinated ether combination. The second copper–lanthanum trifluoride core-shell cathode material...
Perylene diimide discotic columnar liquid-crystalline mesophases (see Figure) can show very high electron mobilities under ambient conditions. While the are strongly dependent on sample morphology and processing conditions, as 1.3 cm2 V–1 s–1 measured, greater than that of amorphous silicon. Supporting information for this article is available WWW http://www.wiley-vch.de/contents/jc_2089/2005/c0027_s.pdf or from author. Please note: The publisher not responsible content functionality any...
Indium−tin oxide (ITO) electrodes have been modified with both fluorinated alkyl and aryl phosphonic acids [n-hexylphosphonic acid (HPA) n-octadecylphosphonic (ODPA); 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl (FHOPA), pentafluorobenzyl (PFBPA), tetrafluorobenzyl-1,4-diphosphonic (TFBdiPA)]. These are modifiers designed to control wetting properties toward nonpolar molecular solids provide a wide range of tunability in effective surface work function. The nature attachment changes...
The synthesis, self-assembly, conductivity, and rheological properties of ABA triblock brush polymers (BBCPs) with grafted polystyrene (A block, NPS = 21) poly(ethylene oxide) (B NPEO 45) side chains are reported. Two backbone molecular weights (NA:NB:NA 11:78:11 15:119:15) were investigated lithium bis(trifluoromethane)sulfonimide (LiTFSI) doping ratios 2 ≤ [EO]:[Li+] 20. Blends 10 suppress PEO crystallization self-assemble into hexagonally packed cylinders the minority gPS component....
We report a nanolithography technique that allows simultaneous direct control of the local chemistry and topography thin polymer films. Specifically, heated atomic force microscope (AFM) tip can write sub-15 nm hydrophilic features onto hydrophobic at rate 1.4 mm per s. The thermally activated chemical reactions changes depend on composition polymer, raster speed, temperature AFM tip/sample interface, normal load. This method is conceptually simple, direct, extremely rapid, achievable in...
Benzylphosphonic acids with various fluorine substitutions are designed and synthesized. They used to modify ITO such that the work function can be tuned over a range of 1.2 eV while keeping surface energy relatively constant. The experimentally measured changes also compared agree well those estimated from DFT calculations. Detailed facts importance specialist readers published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. made available...
We present a theoretical characterization, based on density functional theory, of the indium tin oxide surface and nature binding sites that determine adsorption phosphonic acid monolayers. The validity our description is assessed by comparing first-principles results to X-ray photoelectron spectroscopy data.
Nuclear magnetic resonance spectroscopy can reveal the strength of substrate interactions with heterogeneous catalysts.
A remarkable effect from the modification of electronic and geometric properties Pd nanoparticles by use polymer pendant groups bound to surface palladium is reported. The degree electron promotion under ambient conditions was found be dependent on availability lone pair electrons groups.
The selective electrochemical reduction of CO2 to CO in water by a Re(tBu-bpy)(CO)3Cl catalyst incorporated into multi-walled carbon nanotubes (MWCNT) was investigated. Current densities ∼4 mA/cm2 and selectivities (FECO) 99% were achieved at −0.56 V vs RHE CO2-saturated aqueous KHCO3 solutions. has been widely studied as homogeneous organic solvents. Supporting on MWCNTs increases current densities, decreases overpotential, retains selectivity for CO, allows operation pH = 7.3 compared the...
(E)-4,4'-Bis{bis(4-methoxyphenyl)amino}stilbene, 1, (E,E)-1,4-bis[4-{bis(4-methoxyphenyl)amino}styryl]benzene, 2, and two longer homologues, (E,E,E)-4,4'-bis[4-{bis(4-methoxyphenyl)amino}styryl]stilbene, 3, (E,E,E,E)-1,4-bis(4-[4-{bis(4-methoxyphenyl)amino}styryl]styryl)benzene, 4, have been oxidized to their mono- dications using tris(4-bromophenyl)aminium hexachloroantimonate. The intervalence charge-transfer (IVCT) band of 1+ is narrow asymmetric exhibits only weak solvatochromism....
A complex featuring two triarylamine redox centers bridged by Pt, trans-bis(triethylphosphine)-bis{4-[bis(4-methoxyphenyl)amino]phenylethynyl} platinum(II), has been synthesized as a model system for pi-conjugated Pt-containing polymers. Analysis of the intervalence charge-transfer band displayed its mixed-valence monocation affords quantitative assessment electronic delocalization through Pt bridge; this is found to be only slightly smaller than that determined benzene-bridged analogue....
Six N,N′,5,11-tetrasubstituted coronene-2,3,8,9-tetracarboxydiimides have been synthesised incorporating 3,4,5-tri(n-dodecyloxy)phenyl or 2-(n-decyl)-n-tetradecyl groups in various positions. Differential scanning calorimetry, polarised optical microscopy, and X-ray diffraction indicate that all form columnar discotic mesophases from around room temperature to 200 °C. Charge-carrier mobility values, which energetic considerations suggest are electron determined non-aligned samples cooled the...
We used statistical mechanics to design polymers that defy conventional wisdom by self-assembling into "megasupramolecules" (≥5000 kg/mol) at low concentration (≤0.3 weight percent). Theoretical treatment of the distribution individual subunits—end-functional polymers—among cyclic and linear supramolecules (ring-chain equilibrium) predicts megasupramolecules can form total polymer if, only backbones are long (>400 end-association strength is optimal. Viscometry scattering measurements...
Rapid advances in small satellite (often referred to as CubeSats) technology are providing opportunities for space exploration a wide range of users (in particular universities) at substantially reduced costs. Many the capabilities provided by larger satellites and spacecraft (>2000 kg) now available through technologies. Ongoing improvements attitude control, propulsion, advanced communications, scientific instrumentation continue enhance their benefits, even within such strict volume mass...
Exploration missions to the moons of outer planets (such as Europa) pose unique challenges regarding design spacecraft power source. Current aerospace qualified primary battery technologies cannot adequately meet mass and volume requirements proposed missions. Although they have not been used in prior deep space landed missions, lithium carbon-fluoride (Li/CFx) were identified a potentially viable option, both with without blends manganese dioxide (MnO2). To performance over intended...
Li-ion batteries are being widely used in planetary missions, based on their impressive performance characteristics, including high specific energy, long life, and the ability to operate over a wide temperature range. Custom large-format cells were early e.g., Mars Rovers, Landers, Jupiter Orbiters. At same time, several other robotic missions have utilized planning utilize commercial 18650 lithium-ion cells, Express, Lunar Reconnaissance Orbiter, Europa Clipper, as well human-rated...
An isomeric mixture of a tris(pentafluorobenzyl ester) derivative hexaazatrinaphthylene forms stable amorphous films with an effective charge-carrier mobility 0.02 cm2/Vs, while the pure 2,8,15-isomer exhibits widely differing morphologies and carrier mobilities (0.001-0.07 cm2/Vs), depending critically on processing conditions.
The electron spin resonance spectra of the radical cations 4,4′-bis[di(4-methoxyphenyl)amino]tolane, E-4,4′-bis[di(4-methoxyphenyl)amino]stilbene, and E,E-1,4-bis{4-[di(4-methoxyphenyl)amino]styryl}benzene in dichloromethane exhibit five lines over a wide temperature range due to equivalent coupling two 14N nuclei, indicating either delocalization between both nitrogen atoms or rapid intramolecular transfer on time scale. In contrast, those...
Postsynthetic modification of a porous MOF, Zn4O(trans-4,4′-stilbene dicarboxylate)3, with Br2 results in diastereoselective bromination the stilbene units. This is heterogeneous process, stereocontrol originating rigidity coordinated ligand and nature which allows "solution-like" access to reactive sites. X-ray diffraction N2 sorption studies suggest that partial serves increase stability this interpenetrated MOF structure.