Monday, January 04, 2010

Experimental Determination of Single CdSe Nanowire Absorption Cross Sections through Photothermal Imaging

Experimental Determination of Single CdSe Nanowire Absorption Cross Sections through Photothermal Imaging: "ACS Nano, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Thursday, December 31, 2009

Synthesis, characterization, and evaluation of lubrication properties of composites of ordered mesoporous carbons and luminescent CePO4:Tb nanocrystals

Synthesis, characterization, and evaluation of lubrication properties of composites of ordered mesoporous carbons and luminescent CePO4:Tb nanocrystals: "

Abstract  Having new potential applications in forging processes in mind, composites of an ordered mesoporous carbon and luminescent
metal phosphate nanocrystals were synthesized for the first time. Three kinds of CMK-3/CePO4:Tb nanocomposites were prepared by treating a mesoporous CMK-3 host with different lanthanide phosphate precursor solutions.
Characterization of the obtained nanocomposites by small-angle X-ray scattering, wide-angle X-ray diffraction, transmission
electron microscopy, thermogravimetry, and nitrogen physisorption analysis showed that in two cases, the nanocrystals (ca.
2–3 nm in size) were located inside the mesopores, whereas in the third case the nanocystals (ca. 6 nm in size) merely adhered
to the outer surfaces of the carbon particles. The CMK-3 and the two nanocomposites had ordered hexagonal structures (space
group p6mm); all the materials possessed amorphous carbon walls. After combustion of the nanocomposites, the residues upon excitation
with UV light exhibited the typical green luminescence of Tb3+. A preliminary evaluation of the lubrication properties of the CMK-3 and one nanocomposite material was performed. The friction
factors determined by means of ring upsetting tests revealed that the carbon materials were able to lower frictional forces
although they were 3–4 times less efficient than a commercial graphite-based reference lubricant.


  • Content Type Journal Article
  • DOI 10.1007/s10853-009-4130-3
  • Authors

    • Falk Heinroth, Leibniz Universität Hannover Institut für Anorganische Chemie Callinstr. 9 30167 Hannover Germany
    • Dominic Gruss, Institut für Integrierte Produktion gGmbH Holleritallee 6 30419 Hannover Germany
    • Sven Müller, Institut für Integrierte Produktion gGmbH Holleritallee 6 30419 Hannover Germany
    • Florian Waltz, Leibniz Universität Hannover Institut für Anorganische Chemie Callinstr. 9 30167 Hannover Germany
    • Julia Martynczuk, Leibniz Universität Hannover Institut für Physikalische Chemie und Elektrochemie Callinstr. 3A 30167 Hannover Germany
    • Armin Feldhoff, Leibniz Universität Hannover Institut für Physikalische Chemie und Elektrochemie Callinstr. 3A 30167 Hannover Germany
    • Peter Behrens, Leibniz Universität Hannover Institut für Anorganische Chemie Callinstr. 9 30167 Hannover Germany
    • Michael Wiebcke, Leibniz Universität Hannover Institut für Anorganische Chemie Callinstr. 9 30167 Hannover Germany


"

Luminescence properties of double-perovskite Sr2Ca1−2xEuxNaxMoO6 red-emitting phosphors prepared by the citric acid-assisted sol–gel method

Luminescence properties of double-perovskite Sr2Ca1−2xEuxNaxMoO6 red-emitting phosphors prepared by the citric acid-assisted sol–gel method: "

Abstract  Double-perovskite Sr2Ca1−2x
Eu
x
Na
x
MoO6 red-emitting phosphors were prepared by the citric acid-assisted sol–gel method, and their luminescence properties were investigated
as a function of sintering temperature and Eu3+-doping concentration. B-site substituted Sr2Ca0.8Eu0.1Na0.1MoO6 phosphor, in which Na+ ions act as charge compensators, was selected to study the thermal behavior, phase structure, microstructure, and photoluminescence
property under different sintering temperatures. The photoluminescence studies on Sr2Ca1−2x
Eu
x
Na
x
MoO6 (x = 0.02, 0.05, 0.10, 0.15, 0.2) show that a dominant red emission line at around 594 nm, which is due to the Eu3+ magnetic dipole transition of 5D07F1, is observed under different Eu3+ excitations (396 and 412 nm). Further, Eu3+ dopant content dependent emission spectra investigations of Sr2Ca1−2x
Eu
x
Na
x
MoO6 phosphors indicates that, when the Eu3+ concentrations x = 0.05, there are minimum differences between the emission intensity of 5D07F1 transition at 594 nm and that of 5D07F2 transition at 615 nm. With increasing Eu3+ concentration, the variation of the emission intensities between the two transitions keep nearly invariable and Sr2Ca0.8Eu0.1Na0.1MoO6 phosphor has the strongest red emission in this series.


  • Content Type Journal Article
  • DOI 10.1007/s10853-009-4123-2
  • Authors

    • Zhiguo Xia, China University of Geosciences School of Materials Sciences and Technology Beijing 100083 China
    • Jianfeng Sun, Beijing Technology and Business University College of Chemistry and Environmental Engineering Beijing 100048 China
    • Haiyan Du, Beijing Technology and Business University College of Chemistry and Environmental Engineering Beijing 100048 China
    • Daimei Chen, China University of Geosciences School of Materials Sciences and Technology Beijing 100083 China
    • Jiayue Sun, Beijing Technology and Business University College of Chemistry and Environmental Engineering Beijing 100048 China


"

Use of a Rapid Cytotoxicity Screening Approach To Engineer a Safer Zinc Oxide Nanoparticle through Iron Doping

Use of a Rapid Cytotoxicity Screening Approach To Engineer a Safer Zinc Oxide Nanoparticle through Iron Doping: "ACS Nano, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Electronic Structures of the CdSe/CdS Core−Shell Nanorods

Electronic Structures of the CdSe/CdS Core−Shell Nanorods: "ACS Nano, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Ligand-Controlled Polytypism of Thick-Shell CdSe/CdS Nanocrystals

Ligand-Controlled Polytypism of Thick-Shell CdSe/CdS Nanocrystals: "Journal of the American Chemical Society, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Chemical Control of the Photoluminescence of CdSe Quantum Dot−Organic Complexes with a Series of Para-Substituted Aniline Ligands

Chemical Control of the Photoluminescence of CdSe Quantum Dot−Organic Complexes with a Series of Para-Substituted Aniline Ligands: "Journal of the American Chemical Society, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Synthesis of Dispersible Pd@CeO2 Core−Shell Nanostructures by Self-Assembly

Synthesis of Dispersible Pd@CeO2 Core−Shell Nanostructures by Self-Assembly: "Journal of the American Chemical Society, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Wednesday, December 30, 2009

Preparation of Highly Active, Low Au-Loaded, Au/CeO2 Nanoparticle Catalysts That Promote CO Oxidation at Ambient Temperatures

Preparation of Highly Active, Low Au-Loaded, Au/CeO2 Nanoparticle Catalysts That Promote CO Oxidation at Ambient Temperatures: "The Journal of Physical Chemistry C, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Novel Light-Emitting Ternary Eu3+ Complexes Based on Multifunctional Bidentate Aryl Phosphine Oxide Derivatives: Tuning Photophysical and Electrochemical Properties toward Bright Electroluminescence

Novel Light-Emitting Ternary Eu3+ Complexes Based on Multifunctional Bidentate Aryl Phosphine Oxide Derivatives: Tuning Photophysical and Electrochemical Properties toward Bright Electroluminescence: "The Journal of Physical Chemistry C, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Influence of ZnS and MgO Shell on the Photoluminescence Properties of ZnO Core/Shell Nanowires

Influence of ZnS and MgO Shell on the Photoluminescence Properties of ZnO Core/Shell Nanowires: "The Journal of Physical Chemistry C, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Mesoporous Titania (A) Nanoparticles Prepared by a Solvothermally Treated Organic Small Molecule System: Formation Mechanism and Behavior in Photocatalysis and Dye-Sensitized Solar Cells

Mesoporous Titania (A) Nanoparticles Prepared by a Solvothermally Treated Organic Small Molecule System: Formation Mechanism and Behavior in Photocatalysis and Dye-Sensitized Solar Cells: "The Journal of Physical Chemistry C, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Ultrafast Charge Carrier Relaxation and Charge Transfer Dynamics of CdTe/CdS Core−Shell Quantum Dots as Studied by Femtosecond Transient Absorption Spectroscopy

Ultrafast Charge Carrier Relaxation and Charge Transfer Dynamics of CdTe/CdS Core−Shell Quantum Dots as Studied by Femtosecond Transient Absorption Spectroscopy: "The Journal of Physical Chemistry C, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Ambient Large-Scale Template-Mediated Synthesis of High-Aspect Ratio Single-Crystalline, Chemically Doped Rare-Earth Phosphate Nanowires for Bioimaging

Ambient Large-Scale Template-Mediated Synthesis of High-Aspect Ratio Single-Crystalline, Chemically Doped Rare-Earth Phosphate Nanowires for Bioimaging: "ACS Nano, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

A Hybrid Nanosensor for TNT Vapor Detection

A Hybrid Nanosensor for TNT Vapor Detection: "Nano Letters, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Monday, December 28, 2009

Uniform YF3:Yb,Er up-conversion nanophosphors of various morphologies synthesized in polyol media through an ionic liquid

Uniform YF3:Yb,Er up-conversion nanophosphors of various morphologies synthesized in polyol media through an ionic liquid: "

Abstract  We describe a facile procedure for the synthesis at low temperature (120 °C) of water-dispersible uniform YF3:Yb,Er up-conversion nanophosphors of various morphologies (rhombic and spheroidal) by homogeneous precipitation in polyol
solutions containing different lanthanide salts and an ionic liquid (1-butyl, 2-methylimidazolium tetrafluoroborate) as fluoride
source. It is shown that the shape of the obtained nanoparticles is mainly determined by the nature of both, the polyol and
the lanthanide precursors, which also affects to their colloidal stability in water suspensions. These morphological differences
are explained on the basis of a different mechanism of particle formation. The efficiency of the up-conversion processes in
the synthesized rhombic and spheroidal nanoparticles is also comparatively analyzed and the observed differences are justified
on the basis of the different impurities incorporated to the nanophosphors during their synthesis process.


  • Content Type Journal Article
  • Category Research Paper
  • DOI 10.1007/s11051-009-9824-6
  • Authors

    • Nuria O. Nuñez, CSIC-US Instituto de Ciencia de Materiales de Sevilla Americo Vespucio 49 41092 Isla de la Cartuja, Sevilla Spain
    • Marta Quintanilla, C-IV, Universidad Autónoma de Madrid Depto. Física de Materiales Madrid Spain
    • Eugenio Cantelar, C-IV, Universidad Autónoma de Madrid Depto. Física de Materiales Madrid Spain
    • Fernando Cussó, C-IV, Universidad Autónoma de Madrid Depto. Física de Materiales Madrid Spain
    • Manuel Ocaña, CSIC-US Instituto de Ciencia de Materiales de Sevilla Americo Vespucio 49 41092 Isla de la Cartuja, Sevilla Spain


"

Formation and Luminescence Phenomena of LaF3:Ce3+ Nanoparticles and Lanthanide−Organic Compounds in Dimethyl Sulfoxide

Formation and Luminescence Phenomena of LaF3:Ce3+ Nanoparticles and Lanthanide−Organic Compounds in Dimethyl Sulfoxide: "The Journal of Physical Chemistry C, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Upconversion for White Light Generation by a Single Compound

Upconversion for White Light Generation by a Single Compound: "Journal of the American Chemical Society, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Combining Aurophilic Interactions and Halogen Bonding To Control the Luminescence from Bimetallic Gold−Silver Clusters

Combining Aurophilic Interactions and Halogen Bonding To Control the Luminescence from Bimetallic Gold−Silver Clusters: "Journal of the American Chemical Society, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Highly Sensitive Emission Sensor Based on Surface Plasmon Enhanced Energy Transfer between Gold Nanoclusters and Silver Nanoparticles

Highly Sensitive Emission Sensor Based on Surface Plasmon Enhanced Energy Transfer between Gold Nanoclusters and Silver Nanoparticles: "The Journal of Physical Chemistry C, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Powder Synthesis of Y-α-SiAlON and Its Potential as a Phosphor Host

Powder Synthesis of Y-α-SiAlON and Its Potential as a Phosphor Host: "The Journal of Physical Chemistry C, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Surfactant-free Synthesis of Ultrasmall Gold Nanoclusters

Surfactant-free Synthesis of Ultrasmall Gold Nanoclusters: "The Journal of Physical Chemistry C, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Plasmonic Ratchet Wheels: Switching Circular Dichroism by Arranging Chiral Nanostructures

Plasmonic Ratchet Wheels: Switching Circular Dichroism by Arranging Chiral Nanostructures: "Nano Letters, Volume 9, Issue 11, Page 3945-3948, November 11, 2009."

Surface-Enhanced Raman Spectroscopy and Homeland Security: A Perfect Match?

Surface-Enhanced Raman Spectroscopy and Homeland Security: A Perfect Match?: "ACS Nano, Volume 3, Issue 10, Page 2859-2869, October 27, 2009."

Efficient and Switchable Manganese Luminescence in MnF2:Ce Nanocrystals

Efficient and Switchable Manganese Luminescence in MnF2:Ce Nanocrystals: "The Journal of Physical Chemistry C, Volume 113, Issue 47, Page 20271-20274, November 26, 2009."

Spectroscopic Properties of Persistent Luminescence Phosphors: Lu2O3:Tb3+,M2+ (M = Ca, Sr, Ba)

Spectroscopic Properties of Persistent Luminescence Phosphors: Lu2O3:Tb3+,M2+ (M = Ca, Sr, Ba): "The Journal of Physical Chemistry C, Volume 113, Issue 47, Page 20493-20498, November 26, 2009."

Highly Fluorescent Open-Shell NIR Dyes: The Time-Dependence of Back Electron Transfer in Triarylamine-Perchlorotriphenylmethyl Radicals

Highly Fluorescent Open-Shell NIR Dyes: The Time-Dependence of Back Electron Transfer in Triarylamine-Perchlorotriphenylmethyl Radicals: "The Journal of Physical Chemistry C, Volume 113, Issue 49, Page 20958-20966, December 10, 2009."

Plasmonic Lens Made of Multiple Concentric Metallic Rings under Radially Polarized Illumination

Plasmonic Lens Made of Multiple Concentric Metallic Rings under Radially Polarized Illumination: "Nano Letters, Volume 9, Issue 12, Page 4320-4325, December 9, 2009."

Transparent Conductive Coatings by Printing Coffee Ring Arrays Obtained at Room Temperature

Transparent Conductive Coatings by Printing Coffee Ring Arrays Obtained at Room Temperature: "ACS Nano, Volume 3, Issue 11, Page 3537-3542, November 24, 2009."

Selection of Metal Oxide Charge Transport Layers for Colloidal Quantum Dot LEDs

Selection of Metal Oxide Charge Transport Layers for Colloidal Quantum Dot LEDs: "ACS Nano, Volume 3, Issue 11, Page 3581-3586, November 24, 2009."

Ag@SiO2 Core−Shell Nanoparticles for Probing Spatial Distribution of Electromagnetic Field Enhancement via Surface-Enhanced Raman Scattering

Ag@SiO2 Core−Shell Nanoparticles for Probing Spatial Distribution of Electromagnetic Field Enhancement via Surface-Enhanced Raman Scattering: "ACS Nano, Volume 3, Issue 11, Page 3493-3496, November 24, 2009."

Monodisperse Upconverting Nanocrystals by Microwave-Assisted Synthesis

Monodisperse Upconverting Nanocrystals by Microwave-Assisted Synthesis: "ACS Nano, Volume 3, Issue 11, Page 3804-3808, November 24, 2009."

Electron Transfer-Induced Blinking in Ag Nanodot Fluorescence

Electron Transfer-Induced Blinking in Ag Nanodot Fluorescence: "The Journal of Physical Chemistry C, Volume 113, Issue 47, Page 20264-20270, November 26, 2009."

Intensely Luminescent Gold(I)−Silver(I) Cluster with Hypercoordinated Carbon

Intensely Luminescent Gold(I)−Silver(I) Cluster with Hypercoordinated Carbon: "Journal of the American Chemical Society, Volume 131, Issue 46, Page 16634-16635, November 25, 2009."

Family of Multifunctional Layered-Lanthanum Crystalline Nanowires with Hierarchical Pores: Hydrothermal Synthesis and Applications

Family of Multifunctional Layered-Lanthanum Crystalline Nanowires with Hierarchical Pores: Hydrothermal Synthesis and Applications: "Journal of the American Chemical Society, Volume 131, Issue 46, Page 16953-16960, November 25, 2009."

Facile Hydrothermal Synthesis and Luminescent Properties of Large-Scale GdVO4:Eu3+ Nanowires

Facile Hydrothermal Synthesis and Luminescent Properties of Large-Scale GdVO4:Eu3+ Nanowires: "Crystal Growth & Design, Volume 9, Issue 12, Page 5101-5107, December 2, 2009."

Triplet Sensitized Red-to-Blue Photon Upconversion

Triplet Sensitized Red-to-Blue Photon Upconversion: "The Journal of Physical Chemistry Letters, Volume 0, Issue 0, Page 195-200, Articles ASAP (As Soon As Publishable)."

Synthesis of PbS Nanorods and Other Ionic Nanocrystals of Complex Morphology by Sequential Cation Exchange Reactions

Synthesis of PbS Nanorods and Other Ionic Nanocrystals of Complex Morphology by Sequential Cation Exchange Reactions: "Journal of the American Chemical Society, Volume 131, Issue 46, Page 16851-16857, November 25, 2009."

The first solid-phase route to fabricate and size-tune gold nanoparticles at room temperature

The first solid-phase route to fabricate and size-tune gold nanoparticles at room temperature: "


Dipen Debnath, Sung H. Kim, Kurt E. Geckeler

(Paper from J. Mater. Chem.)

Dipen Debnath, J. Mater. Chem., 2009, DOI: 10.1039/b905260g

To cite this article before page numbers are assigned, use the DOI form of citation above.


The content of this RSS Feed (c) The Royal Society of Chemistry"

Near-Infrared Fluorescent NanoGUMBOS for Biomedical Imaging

Near-Infrared Fluorescent NanoGUMBOS for Biomedical Imaging: "ACS Nano, Volume 3, Issue 12, Page 3854-3860, December 22, 2009."

In Situ Intracellular Spectroscopy with Surface Enhanced Raman Spectroscopy (SERS)-Enabled Nanopipettes

In Situ Intracellular Spectroscopy with Surface Enhanced Raman Spectroscopy (SERS)-Enabled Nanopipettes: "ACS Nano, Volume 3, Issue 11, Page 3529-3536, November 24, 2009."

Highly Scattering, Surface-Enhanced Raman Scattering-Active, Metal Nanoparticle-Coated Polymers Prepared via Combined Swelling−Heteroaggregation

Highly Scattering, Surface-Enhanced Raman Scattering-Active, Metal Nanoparticle-Coated Polymers Prepared via Combined Swelling−Heteroaggregation: "Chemistry of Materials, Volume 21, Issue 23, Page 5654-5663, December 8, 2009."

General Nonaqueous Sol−Gel Synthesis of Nanostructured Sm2O3, Gd2O3, Dy2O3, and Gd2O3:Eu3+ Phosphor

General Nonaqueous Sol−Gel Synthesis of Nanostructured Sm2O3, Gd2O3, Dy2O3, and Gd2O3:Eu3+ Phosphor: "The Journal of Physical Chemistry C, Volume 113, Issue 50, Page 21034-21041, December 17, 2009."

Preparation and Characterization of Upconversion Luminescent NaYF4:Yb3+, Er3+ (Tm3+)/PMMA Bulk Transparent Nanocomposites Through In Situ Photopolymerization

Preparation and Characterization of Upconversion Luminescent NaYF4:Yb3+, Er3+ (Tm3+)/PMMA Bulk Transparent Nanocomposites Through In Situ Photopolymerization: "The Journal of Physical Chemistry C, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Synthesis, Crystal Growth, and Photoluminescence Properties of YAG:Eu3+ Phosphors by High-Energy Ball Milling and Solid-State Reaction

Synthesis, Crystal Growth, and Photoluminescence Properties of YAG:Eu3+ Phosphors by High-Energy Ball Milling and Solid-State Reaction: "The Journal of Physical Chemistry C, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Room-Temperature Synthesis and Luminescent Properties of Single-Crystalline SrMoO4 Nanoplates

Room-Temperature Synthesis and Luminescent Properties of Single-Crystalline SrMoO4 Nanoplates: "The Journal of Physical Chemistry C, Volume 113, Issue 49, Page 20795-20799, December 10, 2009."

Device-Scale Perpendicular Alignment of Colloidal Nanorods

Device-Scale Perpendicular Alignment of Colloidal Nanorods: "Nano Letters, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Metal Nanoparticles with Gain toward Single-Molecule Detection by Surface-Enhanced Raman Scattering

Metal Nanoparticles with Gain toward Single-Molecule Detection by Surface-Enhanced Raman Scattering: "Nano Letters, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Synthesis, Morphology, and Optical Characterization of Nanocrystalline Er3+:Y2O3

Synthesis, Morphology, and Optical Characterization of Nanocrystalline Er3+:Y2O3: "The Journal of Physical Chemistry C, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Phase-Controlled Synthesis of Colloidal In2O3 Nanocrystals via Size-Structure Correlation

Phase-Controlled Synthesis of Colloidal In2O3 Nanocrystals via Size-Structure Correlation: "Chemistry of Materials, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Luminescence properties and electronic structure of Sm3+-doped YAl3B4O12

Luminescence properties and electronic structure of Sm3+-doped YAl3B4O12: "

Abstract  The luminescence properties of Sm3+ ions in YAl3B4O12 were studied upon synchrotron excitation in the 3.8–11 eV region. In addition to the 4f → 4f excitation bands, the excitation spectra of the Sm3+ emission contain broad bands at 6.1 and ~7.0 eV. These bands are attributed to charge transfer transition in Sm3+–O2− complexes and 4f → 5d transition of Sm3+ ions, respectively. The optical absorption edge of YAl3B4O12 was determined at 7.3 eV. A comparison with the results of electronic structure calculations on YAl3B4O12 is also made.


  • Content Type Journal Article
  • DOI 10.1007/s10853-009-4104-5
  • Authors

    • V. P. Dotsenko, Physico-Chemical Institute, Ukrainian Academy of Sciences 86 Lustdorfskaya doroga 65080 Odessa Ukraine
    • I. V. Berezovskaya, Physico-Chemical Institute, Ukrainian Academy of Sciences 86 Lustdorfskaya doroga 65080 Odessa Ukraine
    • N. P. Efryushina, Physico-Chemical Institute, Ukrainian Academy of Sciences 86 Lustdorfskaya doroga 65080 Odessa Ukraine
    • A. S. Voloshinovskii, Ivan Franko National University of Lviv 8 Kyryla i Mefodiya str. 79005 Lviv Ukraine
    • G. B. Stryganyuk, Ivan Franko National University of Lviv 8 Kyryla i Mefodiya str. 79005 Lviv Ukraine


"

Alignment, Rotation, and Spinning of Single Plasmonic Nanoparticles and Nanowires Using Polarization Dependent Optical Forces

Alignment, Rotation, and Spinning of Single Plasmonic Nanoparticles and Nanowires Using Polarization Dependent Optical Forces: "Nano Letters, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Synthesis of Stable Block-Copolymer-Protected NaYF4:Yb3+, Er3+ Up-Converting Phosphor Nanoparticles

Synthesis of Stable Block-Copolymer-Protected NaYF4:Yb3+, Er3+ Up-Converting Phosphor Nanoparticles: "Chemistry of Materials, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

New Discotic Mesogens Based on Triphenylene-Fused Triazatruxenes: Synthesis, Physical Properties, and Self-Assembly

New Discotic Mesogens Based on Triphenylene-Fused Triazatruxenes: Synthesis, Physical Properties, and Self-Assembly: "Chemistry of Materials, Volume 0, Issue 0, Articles ASAP (As Soon As Publishable)."

Tuesday, October 21, 2008

Latest Publication

Anderson, J., R. Massaro, Glaspell, G., Bernard, W. and O. Weatherbee.
2008. Hyperspectral Fluorescence Remote Sensing of Landscape Molecular
Probes. Accepted American Society of Photogrammetry and Remote Sensing
(ASPRS) National Meeting, April 28- May 1, 2008. Portland, Orgeon.

Wednesday, August 20, 2008

Vapor Phase Synthesis of Upconverting Y2O3 Nanocrystals Doped with Yb3+, Er3+, Ho3+, and Tm3+ to Generate Red, Green, Blue, and White Light.

Glaspell, Garry; Anderson, John; Wilkins, James R.; El-Shall, M.
Samy. Department of Chemistry, Virginia Commonwealth University,
Richmond, VA, USA. Journal of Physical Chemistry C (2008),
112(30), 11527-11531. Publisher: American Chemical Society, CODEN:
JPCCCK ISSN: 1932-7447. Journal written in English. AN
2008:804676 CAPLUS

Abstract

We report the vapor phase synthesis of upconverting Y2O3 nanocrystals
doped with Yb3+, Er3+, Ho3+, and Tm3+ to generate red, green, blue, and
white light. Incorporating Er3+ within the Yb3+ doped Y2O3 nanocrystals
under 980 nm laser excitation produced orange and yellow upconversion
luminescence tunable by varying the Yb3+ concn. The Yb3+, Er3+, and
Tm3+ codoped Y2O3 nanocrystals exhibited nearly equal intensities of the
red, green, and blue emissions upon 980 nm laser excitation. White
light can be produced by adjusting the concns. of the Ln3+ ions within
the Y2O3 nanocrystals.

Formation of rare-earth upconverting nanoparticles using laser vaporization controlled condensation.

Glaspell, Garry; Wilkins, James R.; Anderson, John; El-Shall, M.
Samy. Virginia Commonwealth Univ. (USA) and U.S. Army Research and
Development Ctr., USA. Proceedings of SPIE (2008), 6940(Pt. 1,
Infrared Technology and Applications XXXIV), 69403B-69403B-7.
Publisher: Society of Photo-Optical Instrumentation Engineers, CODEN:
PSISDG ISSN: 0277-786X. Journal written in English. AN
2008:697307 CAPLUS

Abstract

Rare earth doped upconverting nanoparticles have been synthesized via
laser vaporization controlled condensation (LVCC) and their
photoluminescence properties were characterized using 980 nm laser diode
excitation. This procedure is highly tunable, specifically by
increasing the Yb3+ to Er3+ concn. the obsd. green emission decreases
and the obsd. red emission increases. We have also shown that nearly
equal peaks of blue, green and red emissions producing a virtually white
upconverter could be synthesized by appropriately mixing Tm3+, Ho3+, and
Er3+. We have also investigated the upconversion efficiency in a
variety of lattices including Y2O3, Gd2O3 and La2O3. TEM confirmed that
the as-formed particles were 10 nm in size and XRD indicated that the
overall crystal structure was predominately cubic.

Synthesis of Nanocrystalline TiO2 Particles and Their Structural Characteristics.

Manivannan, A.; Glaspell, G.; Dutta, P. Department of Physics,
West Virginia University, Morgantown, WV, USA. Journal of Cluster
Science (2008), 19(2), 391-399. Publisher: Springer, CODEN: JCSCEB
ISSN: 1040-7278. Journal written in English. AN 2008:557637 CAPLUS

Abstract

Controlled nanosized TiO2 particles of 4-10 nm were synthesized by a
simple hydrolysis method followed by calcination at different temps.
These particles were investigated using X-ray diffraction (XRD),
Photoacoustic/Fourier transform IR (PA/FTIR) spectroscopy, Raman
spectroscopy and ESR (ESR) spectroscopy to understand their structural
properties. X-ray diffraction studies confirmed the anatase phase of
the particles where as the PA/FTIR revealed the bands around 1,500 and
3,300 cm-1 due to -OH bands. ESR spectroscopic investigations carried
out from 5 to 300 K indicated the presence of an ESR line at g = 2.00
emerging from radical species. It is significant to note that the
intensity of the ESR line decreased as the particle size increased.

Growth and Characterization of ZnO, SnO2 and ZnO/SnO2 Nanostructures from the Vapor Phase.

Fouad, O. A.; Glaspell, G.; El-Shall, M. S. Central
Metallurgical Research and Development Institute (CMRDI), Cairo,
Egypt. Topics in Catalysis (2008), 47(1-2), 84-96. Publisher:
Springer, CODEN: TOCAFI ISSN: 1022-5528. Journal written in
English. AN 2008:340240 CAPLUS
Abstract
Zinc oxide (ZnO), tin dioxide (SnO2) and compds. ZnO/SnO2 (ZTO)
nanostructures have been synthesized successfully from the vapor phase
without a catalyst using three different approaches. XRD analyses
showed that ZnO with a wurtzite crystal structure, SnO2 with a rutile
crystal structure and zinc stannate (ZnSnO3) and/or dizinc stannate
(Zn2SnO4) were condensed from the vapor phase when Zn and/or Sn metal
powders or their oxides individually or mixed were used as the starting
materials. The formation of either zinc or dizinc stannate was
controlled by the Zn/Sn ratio and growth technique. SEM and TEM
investigations showed that ZnO grew mainly in the form of wires, rods
and belts. These are believed to be originated from the common tetrapod
structure of ZnO. While SnO2 grew in the form of tetragonal rods with
rectangle-like cross section and nanoparticles, ZTO grew in the form of
nanobelts. The final length, width and thickness were as low as 40, 10
and 5 nm, resp. The driving forces for growth of nanowires, nanorods,
nanobelts, and nanoparticles were found to be vapor d. or supersatn.,
temp., pressure and location of deposition from the source materials.
The optical absorbance and photoluminescence spectra of all samples
showed excitonic character at room temp. implying good crystal quality,
and high photocurrent properties suggesting possible applications in
nanoscaled functional devices such as optoelectronics and gas sensors.

Nanocatalysis on Supported Oxides for CO Oxidation.

Glaspell, Garry; Hassan, Hassan M. A.; Elzatahry, Ahmed; Abdalsayed,
Victor; El-Shall, M. Samy. Department of Chemistry, Virginia
Commonwealth University, Richmond, VA, USA. Topics in Catalysis
(2008), 47(1-2), 22-31. Publisher: Springer, CODEN: TOCAFI ISSN:
1022-5528. Journal written in English. AN 2008:340239 CAPLUS

Abstract

Active gold and palladium nanoparticles supported on a variety of oxides
(CeO2, ZrO2, Al2O3, SiO2, MgO and ZnO) were synthesized using laser
vaporization and microwave irradn. methods. The catalytic activities
for CO oxidn. on the nanoparticle catalysts were evaluated and compared
among different oxide supports. The effect of shape on the catalytic
activity is demonstrated by comparing the activities of the Au and Pd
catalysts deposited on MgO nanocubes and ZnO nanobelts. The Au/CeO2
nanoparticles deposited on MgO nanocubes exhibit high catalytic activity
and stability. The enhanced catalytic activity is attributed to the
presence of a significant concn. of the corner and edge sites in MgO
nanocubes. The Au- and Pd-doped Mn2O3 nanoparticles show promising
results for the low temp. CO oxidn. Several approaches for
incorporating the Au and Pd nanocatalysts within mesoporous oxide
supports are presented and discussed.

Laser synthesis of bimetallic nanoalloys in the vapor and liquid phases and the magnetic properties of PdM and PtM nanoparticles (M = Fe, Co and Ni).

Abdelsayed, Victor; Glaspell, Garry; Nguyen, Minh; Howe, James M.; Samy
El-Shall, M. Department of Chemistry, Virginia Commonwealth
University, Richmond, VA, USA. Faraday Discussions (2008),
138(Nanoalloys), 163-180.

In this work, we present several examples of the synthesis and
characterization of bimetallic nanoparticle alloys using the Laser
Vaporization Controlled Condensation (LVCC) method. In the first
example, the vapor phase synthesis of Au-Ag, Au-Pd, and Au-Pt
nanoparticle alloys are presented. The formation of nanoalloys is
concluded from the observation of one plasmon absorption band at a
wavelength that varies linearly with the gold mole fraction in the
nanoalloy. Both XRD data and HRTEM-EDX data confirm the formation of
nanoparticle alloys and not simply mixts. of the two metal
nanoparticles. Irradn. of a mixt. of Au/Ag nanoparticles dispersed in
water with the 532 nm unfocused laser results in efficient alloying
while the 1064 nm laser radiation results only in evapn. and size redn.
of the unalloyed nanoparticles. Selective absorption of the femtosecond
780 nm radiation by large Au aggregates results in the formation of
smaller aggregates with fractal structures, and no evidence for the
Au-Ag alloy formation. The synthesis of palladium and platinum
nanoparticles alloyed with transition metals such as iron and nickel
using the LVCC method is also presented. The alloyed nanoparticles
(FePd, FePt, NiPd, NiPt, and FeNi) are found to be superparamagnetic.

Tuesday, August 07, 2007

Microwave Synthesis and Optical Properties of Uniform Nanorods and Nanoplates of Rare Earth Oxides.

We report on the rapid prodn., characterization, and spectral properties of uniform nanorods, nanowires, and nanoplates of rare earth oxides M2O3 (M = Pr, Nd, Sm, Eu, Gd, Tb, Dy). The method developed, based on microwave irradn. (MWI), allows the control of the size and shape of the rare earth oxide nanostructures by varying the MWI reaction time and the relative concns. of the org. surfactants. The uniformity of the rods and of the wires is demonstrated in their spontaneous assembly into highly ordered 2D supercrystals. The MWI method provides a unique opportunity for the large-scale synthesis of rare earth nanostructures without suffering thermal gradient effects.

Reversible paramagnetism to ferromagnetism in transition metal-doped TiO2 nanocrystals prepared by microwave irradiation.

TiO2 nanoparticles doped with 1%, 5%, and 10% M (M=Co, Fe, and Ni) were prepd. by microwave irradn. and characterized using x-ray diffraction, transmission electron microscopy, and magnetometry. The as-prepd. samples are found to be paramagnetic at room temp., with the magnetic susceptibility following the Curie-Weiss law in the investigated range of 2-300 K. However, transformation from paramagnetism to room-temp. ferromagnetism (RTFM) was obsd. by hydrogenating the samples at 400 °C. Reheating in air converted the samples back to paramagnetic while rehydrogenating the samples again induced ferromagnetism. It is argued that the reversible RTFM obsd. is due to interaction between the dopant metal ions and oxygen vacancies produced during hydrogenation. X-ray diffraction of the hydrogenated Co- and Fe-doped samples shows only a single TiO2 phase suggesting that the obsd. RTFM may be intrinsic, but for the Ni-doped samples the magnetism may arise from metallic Ni on the surfaces of the TiO2 nanoparticles.

Nanoparticles in astrochemistry: synthesis and characterization of meteorite dust nanoparticles.

Interstellar dust particles (IDPs) constitute most of the solid matter in the universe. Large quantities of IDPs are also present in the Solar System and fall on Earth. IDPs are also of interest as they can catalyze astrochem. reactions and prebiotic synthesis, and their org. contents are believed to have contributed to the origins of life. Their chem. compn. is similar to carbonaceous chondrite comets, asteroids and meteorites. The IDPs are microporous web-like aggregates of 10-100 nm phyllosilicate particles with morphologies similar to particles produced by the Laser Vaporization Controlled Condensation (LVCC) method. IDPs are available only as microscopic samples, and simulated IDPs are needed to study their chem. and catalytic effects. To produce such simulated IDPs, we formed nanoparticles from carbonaceous chondrite meteorites by LVCC processing. The compns., morphologies, particle size distribution, FTIR spectra, and catalytic properties of the meteorite-based nanoparticles were investigated and compared with the original meteorite materials and ref. minerals.

Tuesday, October 17, 2006

Nanocatalysis on Tailored Shape Supports: Au and Pd Nanoparticles Supported on MgO Nanocubes and ZnO Nanobelts.

Active Au and Pd nano-particles supported on MgO nano-cubes, ZnO nano-belts, and transition metal-contg. MgO nano-belts were synthesized by combining evapn. and deposition-pptn. techniques. The high activity and stability of Au/CeO2 and Pd/CeO2 nano-particle catalysts deposited on MgO cubes were remarkable and imply a variety of efficient catalysts can be designed and tested using this approach. The significant increase in concns. of corner and edge sites in MgO nano-cubes make them well-defined supports to study the detailed mechanism of catalytic activity enhancement.