共查询到20条相似文献,搜索用时 625 毫秒
1.
Ilana Abayev Arie Zaban Vladimir G. Kytin Alexey A. Danilin Germà Garcia-Belmonte Juan Bisquert 《Journal of Solid State Electrochemistry》2007,11(5):647-653
Results on the density of sates of nanostructured TiO2 as a function of particle size and temperature are reported. In TiO2 nanoparticles with a mean diameter 10 nm, the density of states (DOS) is strongly temperature-dependent, indicating a rearrangement
of the bandgap states in which the exponential energy parameter (width of the distribution) increases from 0.080 to 50 °C.
For nanoparticles with mean diameters of 20 and 30 nm the DOS is much closer to an exponential distribution, and is much less
sensitive to temperature variations. It is suggested that nanometer confinement has a significant influence on the density
of electronic states for 10-nm particles, while band tailing is similar to that occurring in bulk semiconductors for the larger
particles.
相似文献
Juan BisquertEmail: |
2.
H. P. Zhang L. C. Yang L. J. Fu Q. Cao D. L. Sun Y. P. Wu R. Holze 《Journal of Solid State Electrochemistry》2009,13(10):1521-1527
Recent progress in studies of several types of core-shell structured electrode materials, including TiO2/C, Si/C, Si/SiO
x
, LiCoO2/C, and LiFePO4/C nanocomposites, including details of their preparation and their electrochemical performance is briefly reviewed. Results
clearly show that the coating shell can effectively prevent the aggregation of the nanosized cores, which are the electrochemically
active materials. In addition, the diffusion coefficients of lithium ions can be increased, and the reversibility of lithium
intercalation and deintercalation is improved. As a result, the cycling behavior is greatly improved. The reviewed results
suggest that core-shell nanocomposites are a good starting point for further development of new promising electrode materials.
相似文献
Y. P. WuEmail: |
R. Holze (Corresponding author)Email: |
3.
Niki Baccile Anna Fischer Beatriz Julián-López David Grosso Clément Sanchez 《Journal of Sol-Gel Science and Technology》2008,47(2):119-123
Core-shell and homogeneous distributions of functionalized cerium oxide nanoparticles within spray-dried mesostructured silica
spheres are achieved by modification of synthesis parameters such as the templating agent and nanoparticle capping functions.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
相似文献
Clément Sanchez (Corresponding author)Email: |
4.
Garcia Jarem R. Peres Laura O. Fernandes Mauro R. Gruber Jonas Nart Francisco C. 《Journal of Solid State Electrochemistry》2004,8(2):122-126
In this communication we describe the electrochemical synthesis of poly(2,5-dicyano-p-phenylenevinylene) (DCNPPV) polymer films on indium tin oxide substrates. We investigate the purity, morphology, absorption and emission properties of the film. The purity was checked by infrared spectroscopy. The film formed presented spectroscopic purity equivalent to the chemically prepared PPV that was dialyzed for one week. Scanning electron microscopy of the surface revealed a grain-like morphology. The absorption and emission spectra showed absorption and emission bands at 420 nm and 575 nm, respectively, with the absorption onset at 422 nm, which corresponds to an energy gap of 2.25 eV. The electrochemical determination of the energy gap gives 2.05 eV, thus quite close to the optical energy gap at the onset of absorption. The EA and IP were determined by electrochemical measurements and are 3.46 eV and 5.51 eV, respectively.
相似文献
Francisco C. NartEmail: |
5.
The thermodynamic phase behavior and the morphology in thin films of poly(3-hexylthiophene) (P3HT) has been studied using calorimetry, X-ray scattering, and scanning force microscopy (AFM). Around 225 °C a phase transition from the crystalline state to a layered, liquid crystalline structure occurs in regioregular P3HT, while the regiorandom counterpart material is disordered at all temperatures and displays a glass transition temperature Tg–3 °C. Regioregular P3HT is semicrystalline and forms needle or plate like crystallites which in solution cast thin films are oriented with respect to the substrate. Films produced by spin coating display a non-equilibrium structure with reduced order and orientation. Annealing of these films in the liquid crystalline state leads to the formation of a morphology similar to the one observed in solution cast films.
相似文献
T. Thurn-AlbrechtEmail: |
6.
Malcolm H. Chisholm Jason S. D’Acchioli Christopher M. Hadad 《Journal of Cluster Science》2007,18(1):27-49
The electronic structures and the physical properties (vertical excitation energies, vibrational stretching frequencies, and
bond lengths) of a variety of M–M quadruply bonded (M = Mo, W) complexes are investigated using density functional theory
(DFT). By utilizing a variety of pure and hybrid exchange-correlation (XC) functionals and a number basis sets, we are able
to recommend a theoretical methodology for most efficiently probing the electronic structures of homoleptic M2(O2CR)4 and bridged M2(O2C-X-CO2)M2 (R = organic group, typically H; X = conjugated organic group) complexes.
相似文献
Jason S. D’AcchioliEmail: |
7.
Regina Mikulíková Václav Švorčík Josef Náhlík Tomáš Sopuch Pavel Havelka 《Cellulose (London, England)》2008,15(3):473-479
We studied the physical–chemical properties of polyethylene (PE) films doped with calcium salt of 6-carboxycellulose (Ca-oxy)
in concentrations 0–20 wt.% and their interactions with cells. The interaction between the PE/Ca-oxy composite film and 3T3
cells has not been described so far. Modification by surface grinding to enhance material cytocompatibility was studied. The
surface wettability of doped films was tested by contact angle measurements and the surface morphology by SEM microscopy and
profilometry. Adhesion and proliferation of tissue cells (3T3 mouse fibroblasts) were studied in vitro on pristine and ground
doped PE films. The ground samples have a higher contact angle values and the number of proliferated cells is greater on the
ground samples than on pristine ones. The presence of Ca-oxy in PE film increases the adhesion of 3T3 cells on the doped substrate
and on ground samples adhere more cells than on pristine ones.
相似文献
Václav ŠvorčíkEmail: |
8.
Daniela Aiello Luca Malfatti Tongjit Kidchob Rosario Aiello Flaviano Testa Iolinda Aiello Mauro Ghedini Massimo La Deda Tonino Martino Maria Casula Plinio Innocenzi 《Journal of Sol-Gel Science and Technology》2008,47(3):283-289
Highly fluorescent materials have been prepared by incorporation of a zinc complex in mesoporous silica thin films with ordered
pore structure. The zinc complex has been introduced into the mesoporous materials via impregnation in an ethanol solution.
The incorporation into the films has been monitored by UV–Vis, Fourier transform infrared spectroscopy and spectroscopic ellipsometry.
After 18 h of immersion in the doping solution the films showed strong blue emission, increase in the refractive index. Leaching
experiments performed by immersing the samples in ethanol or tetrahydrofuran have shown that the chromophore is retained in
the porous matrix.
相似文献
Plinio InnocenziEmail: |
9.
The molecular geometries, relative stabilities, binding energies, and dissociation energies of NaDyBr4 and its molecular ion are discussed. Both the bidentate and tridentate isomers are stable for the neutral species, while
only the bidentate form is stable for NaDyBr4
+.
相似文献
Magdolna Hargittai (Corresponding author)Email: |
10.
11.
Fatemeh Hashemzadeh M. Mehdi Kashani Motlagh Amir Maghsoudipour 《Journal of Sol-Gel Science and Technology》2009,51(2):169-174
In this work, MnO2 nanostructure powders with different crystalline phases have been successfully prepared by hydrothermal and sol–gel methods.
The obtained products were characterized by XRD and SEM techniques and their crystallographic phases and morphological properties
compared. Results showed that α-MnO2, β-MnO2, and δ-MnO2 nanorods were synthesized by hydrothermal method and γ-MnO2 polymorph was obtained by sol–gel method.
相似文献
Amir MaghsoudipourEmail: |
12.
Vaporization enthalpies for the isomeric diazines were discussed within the context of recent measurements and estimation
techniques. It is suggested that pyridazine shows enigmatic behavior.
相似文献
Joel F. Liebman (Corresponding author)Email: |
13.
Sarah Gold Julian Eastoe Roberto Grilli David C. Steytler 《Colloid and polymer science》2006,284(11):1333-1337
A series of highly branched trichain sulfosuccinate surfactants have been synthesized and studied in condensed CO2 and aqueous environments. Aqueous critical micelle concentrations (CMCs) showed a general trend of increasing CMC with decreasing chain length, whereas increased branching appeared to increase solubility in CO2 and aid the dispersion of water. Near infrared spectra confirmed observed cloud with a large increase in solubility above the cloud pressures in this solvent.
相似文献
Julian EastoeEmail: Phone: +44-117-9289180Fax: +44-117-9251295 |
14.
Guy Yardeni Israel Zilbermann Eric Maimon Haim Cohen Dan Meyerstein 《Research on Chemical Intermediates》2009,35(4):543-554
A new CeIII complex was synthesized by mixing the ligand “dioxocyclam” with CeIII ions at pH 8.0 and its redox properties were investigated.
相似文献
Dan Meyerstein (Corresponding author)Email: |
15.
Renat R. Nazmutdinov Michael D. Bronshtein Dmitrii V. Glukhov Tamara T. Zinkicheva 《Journal of Solid State Electrochemistry》2008,12(4):445-451
Solvent dynamics effects on the electroreduction of [PtCl3(H2O)]− at a mercury electrode are explored in the framework of Sumi–Marcus model using an efficient computational scheme. According
to results of density functional calculations, the second electron transfer step may be regarded as rate controlling. The
nonmonotonous influence of solvent viscosity on the reaction rate is predicted and explained in terms of the saddle point
avoidance. The results of model calculations are employed to interpret experimental data reported earlier in the literature.
相似文献
Renat R. NazmutdinovEmail: |
16.
Yan Gao Sabrina Reischmann Johannes Huber Tobias Hanke Rudolf Bratschitsch Alfred Leitenstorfer Stefan Mecking 《Colloid and polymer science》2008,286(11):1329-1334
Single semiconductor quantum dots were embedded into polymer particles with diameters below 0.1 μm by an emulsion polymerization
procedure or via a secondary dispersion approach. The photoluminescence properties of the nanocrystals are retained upon encapsulation,
as demonstrated by fluorescence confocal microscopy.
相似文献
Stefan MeckingEmail: |
17.
Nataliya V. Roznyatovskaya Veronika K. Laurinavichute Galina A. Tsirlina Vladimir M. Mirsky 《Journal of Solid State Electrochemistry》2007,11(7):981-992
Various systems containing immobilized binuclear copper(II) and nickel(II) complexes with Robson type ligand ([M2L]Cl2) are studied and compared in relation to catalysis of hydrogen peroxide reduction. Molecular complexes adsorbed on mercury
and gold, crystalline complexes immobilized in the carbon paste electrode, and complex species entrapped into polyphenol-modified
gold electrodes are considered. Electrocatalysis is assumed to result from the formation of H2O2–[M2L]Cl2 adduct, not from mediating redox transformations. Possible geometry of the formed reaction layers supporting adduct formation
is discussed.
相似文献
Nataliya V. RoznyatovskayaEmail: |
18.
Michael Noyong Buelent Ceyhan Christof M. Niemeyer Ulrich Simon 《Colloid and polymer science》2006,284(11):1265-1273
The formation and the optical features of two-dimensional aggregates formed by DNA-directed immobilization and cross-linking of bifunctional DNA–gold nanoparticles at flat gold substrates are analyzed. The samples are structurally characterized by atomic force microscopy to evaluate the particle size, the particle densities, and the degree of aggregation. The optical characteristics determined by UV/visible measurements are correlated with the structural features observed.
相似文献
Ulrich SimonEmail: |
19.
Saad Alshehri John Burgess Colin D. Hubbard Christopher J. Jones Amit K. Das 《Transition Metal Chemistry》2008,33(4):417-420
The kinetics of substitution by alcohols and by aniline at [tris(3,5-dimethylpyrazolyl)hydroborato]molybdenum nitrosyl dihalides in toluene solution at 298.2 K and at atmospheric pressure
are reported and interpreted in terms of an associative mechanism.
相似文献
Colin D. HubbardEmail: |
20.
I. Berra L. Irusta M. J. Fernández-Berridi Y. R. de Miguel 《Journal of Sol-Gel Science and Technology》2009,49(1):19-28
Novel phenoxy-silica hybrid materials (with 3 wt.% SiO2) have been synthesized using different synthetic procedures. Differential scanning calorimetric (DSC) (Tg), FT-IR and transmission electron microscopy (TEM) results, as well as thermal and mechanical properties, are reported for
these hybrids, which can be classified into three different groups, depending on the number of components synthesized in situ.
Best results in terms of homogeneity (TEM) and mechanical properties have been obtained when the sol–gel process has been
carried out in the presence of a phenoxy resin modified with a pendant alkoxysilane monomer.
相似文献
Y. R. de MiguelEmail: |