Department of Chemistry
Recent Submissions
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XPS for probing the dynamics of surface voltage and photovoltage in GaN
(Elsevier, 2014-12-30)We describe application of two different data gathering techniques of XPS for probing the dynamics of surface voltage and surface photovoltage (SPV) developed in microseconds to seconds time-domain, in addition to the ... -
Transient surface photovoltage in n- and p-GaN as probed by x-ray photoelectron spectroscopy
(American Institute of Physics, 2011)Transient surface photovoltage (SPV) of n and p-GaN was measured using x-ray photoelectron spectroscopy (XPS) with a time resolution of 0.1 s. The measured SPV transients for both n- and p-GaN are << 0.1 s, and for the ... -
Quantum efficiency enhancement in film by making nanoparticles of polyfluorene
(Optical Society of America, 2008)We report on conjugated polymer nanoparticles of polyfluorene that were formed to exhibit higher fluorescence quantum efficiency in film (68%) and reduce undesired emission peak wavelength shifts in film (by 20 nm), compared ... -
White emitting polyfluorene functionalized with azide hybridized on near-UV light emitting diode for high color rendering index
(Optical Society of America, 2008)We develop and demonstrate high-quality white light generation that relies on the use of a single-type simple conjugated polymer of polyfluorene functionalized with azide groups (PFA) integrated on a near-UV LED platform. ... -
Non-radiative resonance energy transfer in bi-polymer nanoparticles of fluorescent conjugated polymers
(Optical Society of America, 2010-01-18)his work demonstrates the comparative studies of non-radiative resonance energy transfer in bi-polymer nanoparticles based on fluorescent conjugated polymers. For this purpose, poly[(9,9-dihexylfluorene) (PF) as a donor ... -
Morphology-Dependent Energy Transfer of Polyflorene Nanoparticeles Decorating InGaN/GaN Quantum-Well Nanopillars
(American Chemical Society, 2013)Conjugated polymer nanoparticles (CPNs), prepared in aqueous dispersion from poly[(9,9-bis{3-bromopropyl}fluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1,3}-thiodia- zole)] (PFBT-Br), are incorporated into a nanopillar architecture ... -
White-emitting Conjugated Polymer Nanoparticles with Cross-Linked Shell for Mechanical Stability and Controllable Photometric Properties in Color-Conversion LED Applications
(American Chemical Society, 2011-03-28)We report on the synthesis and characterization of water-dispersible, mechanically stable conjugated polymer nanoparticles (CPNs) in shelled architecture with tunable emission and controllable photometric properties via ... -
Study of exciton transfer in dense quantum dot nanocomposites
(Royal Society of Chemistry, 2014)Nanocomposites of colloidal quantum dots (QDs) integrated into conjugated polymers (CPs) are key to hybrid optoelectronics, where engineering the excitonic interactions at the nanoscale is crucial. For such excitonic ... -
Weighted-Residual Methods for the Solution of Two-Particle Lippmann-Schwinger Equation without Partial-Wave Decomposition
(Springer Verlag, 2014-01)Recently there has been a growing interest in computational methods for quantum scattering equations that avoid the traditional decomposition of wave functions and scattering amplitudes into partial waves. The aim of the ... -
Electrochemically generated catalyst system with increased specificity and efficiency for olefin metathesis
(Elsevier, 2003-11-01)A facile route for the electrochemical generation of an olefin metathesis catalyst from methylene chloride solution Of WCl6 was described. It was found that reductive, oxidative and pulse electrolysis produced the same ... -
Influence of the sol–gel preparation method on the photocatalytic NO oxidation performance of TiO2/Al2O3 binary oxides
(Elsevier, 2015-03-01)In the current work, TiO2/Al2O3 binary oxide photocatalysts were synthesized via two different sol-gel protocols (P1 and P2), where various TiO2 to Al2O3 mole ratios (0.5 and 1.0) and calcination temperatures (150-1000 ... -
Fabrication of Mesoporous Metal Chalcogenide Nanoflake-Silica Thin Films and Spongy Mesoporous CdS and CdSe
(Wiley Online Library, 2012-02-16)Mesoporous silica metal oxide (ZnO and CdO) thin films have been used as metal ion precursors to produce the first examples of mesoporous silica metal sulfide (meso-SiO2@ZnS, meso-SiO2@CdS) or silica metal selenide ... -
Nanoparticle Labeling of Bone Marrow-Derived Rat Mesenchymal Stem Cells: Their Use in Differentiation and Tracking
(Hindawi Publishing Corporation, 2014)Mesenchymal stem cells (MSCs) are promising candidates for cellular therapies due to their ability to migrate to damaged tissue without inducing immune reaction. Many techniques have been developed to trace MSCs and their ... -
CeOx/Al2O3 thin films on stainless steel substrate - Dynamical X-ray photoelectron spectroscopy investigations
(Elsevier, 2013-06-01)The CeOx/Al2O3 thin films on stainless steel with different ceria loading were subjected to a. c. ( square wave) pulses at various frequencies in the range 10(-3) to 100 kHz while recording X-ray photoelectron spectra. The ... -
Soft X-ray Photoemission Studies of the HfO2/SiO2/Si System
(American Institute of Physics, 2002)Soft x-ray photoelectron spectroscopy with synchrotron radiation was employed to study the valence-band offsets for the HfO2/SiO2/Si and HfO2/SiOxNy/Si systems. We obtained a valence-band offset difference of -1.05+/-0.1 ... -
FT-IR spectroscopic investigation of the reactivity of NOx species adsorbed on Cu2+/ZrO2 and CuSO4/ZrO2 catalysts toward decane
(Elsevier, 2003-04-15)The nature of the NOx species produced on NO adsorption and its co-adsorption with O-2 at room temperature on zirconia-supported copper(II) catalysts has been studied by means of in situ FT-IR spectroscopy. The samples ... -
Routes of formation and composition of NOx complexes adsorbed on palladium-promoted tungstated zirconia
(Elsevier, 2006-03-16)Surface species obtained during the adsorption of NO and NO/O2 coadsorption at room temperature on Pd-free (WZ) and Pd-promoted tungstated zirconia (Pd/WZ) are identified by means of in situ FT-IR spectroscopy. The WZ and ... -
Periodic Mesoporous Hydridosilica-Synthesis of an "Impossible" Material and its Thermal Transformation into Brightly Photoluminescent Periodic Mesoporous Nanocrystal Silicon-Silica Composite
(American Chemical Society, 2011)There has always been a fascination with "impossible" compounds, ones that do not break any rules of chemical bonding or valence but whose structures are unstable and do not exist. This instability can usually be rationalized ... -
Spatially Confined Redox Chemistry in Periodic Mesoporous Hydridosilica-Nanosilver Grown in Reducing Nanopores
(American Chemical Society, 2011-09-26)Periodic mesoporous hydridosilica, PMHS, is shown for the first time to function as both a host and a mild reducing agent toward noble metal ions. In this archetypical study, PMHS microspheres react with aqueous Ag(I) ... -
Supramolecular Assemblies Constructed by Cucurbituril-Catalyzed Click Reaction
(Wiley Online Library, 2011)Cucurbituril homologues are multi-functional macrocycles that can find applications in many areas and have numerous interesting features setting them apart from the other macrocycles. Among them, the ability of one of the ...
