Search results for " interface"
showing 10 items of 1741 documents
Photocatalytic activity of anatase-nickel ferrite heterostructures
2015
The simple co-precipitation route was used to couple commercial TiO2 anatase nanopowder with nickel ferrite (NiFe2O4). The morphology and the crystalline structure of composite nanoparticles were characterised by TEM, N2 adsorption-desorption, XRD and Rietveld refinement, XPS and XAS. The optical and magnetic properties were investigated. After co-precipitation NiFe2O4 nanoparticles, composed of spinel ferrite crystal phase, were formed on the surface of TiO2 anatase nanopowder. The TiO2/NiFe2O4 composite oxide demonstrated large specific surface area, high visible light absorption efficiency and efficient charge carrier separation, compared to pristine anatase TiO2 or pristine NiFe2O4, rep…
Anion Recognition by a Bioactive Diureidodecalin Anionophore: Solid-State, Solution, and Computational Studies
2018
Recent work has identified a bis-(p-nitrophenyl)ureidodecalin anion carrier as a promising candidate for biomedical applications, showing good activity for chloride transport in cells yet almost no cytotoxicity. To underpin further development of this and related compounds, a detailed structural and binding investigation is reported. Crystal structures of the transporter as five solvates confirm the diaxial positioning of urea groups while revealing a degree of conformational flexibility. Structures of complexes with Cl−, Br−, NO3 −, SO4 2− and AcO−, supported by computational studies, show how the binding site can adapt to accommodate these anions. 1H NMR binding studies revealed exception…
Watching adsorption and electron beam induced decomposition on the model system Mo(CO)(6)/Cu(111) by X-ray absorption and photoemission spectroscopies
2013
Abstract An in-depth study of the first steps of electron beam assisted growth of Mo from molybdenum hexacarbonyl on Cu(1 1 1) has been carried out exploiting the complementarity of X-ray photoemission and X-ray absorption spectroscopies. Frank van der Merwe (2D) growth mode has been observed for the completion of the two first monolayers of adsorbed molecules through a simple physisorption process. Irradiation of the Mo(CO)6 deposit by 1 keV electron beam induces a modification of molybdenum coordination, the average number of C-neighbors decreasing from 6 to 3. Decomposed molecules remain on the surface after annealing at 520 K and organize themselves, the molybdenum atoms moving in Cu(1 …
Anthracene-containing PPE-PPV copolymers: Effect of side-chain nature and length on photophysical and photovoltaic properties
2009
Rupali Jadhav1,2, Stefan Turk3, Florian Kuhnlenz1, Vera Cimrova4, Silke Rathgeber5, Daniel A. M. Egbe*,2,3, and Harald Hoppe**,1 1 Institute of Physics, Ilmenau University of Technology, Weimarer Str. 32, 98693 Ilmenau, Germany 2 Linz Institute for Organic Solar Cells (LIOS), Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria 3 Institute for Print and Media Technology, Chemnitz University of Technology, Reichenhainer Str. 70, 09126 Chemnitz, Germany 4 Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovský Sq. 2, 162 06 Prague 6, Czech Republic 5 Johannes Gutenberg-University Mainz, Staudingerweg 7, 55128 Mainz, Germany
Influence of temperature on the synthesis of thiol-stabilized CdTe nanoparticles in aqueous solutions
2010
We have investigated the evolution of thiol-capped cadmium telluride nanocrystals prepared in aqueous solutions at low and room temperature followed by heating at 50–100 °C. The UV–visible absorption spectra, as well as transmission electron microscopy, atomic force microscopy, and dynamic light scattering observations made it possible to reveal differences in size and structure originating from different heating temperatures. It was shown that minimization of the nucleation process temperature provided formation of larger nanoparticles than at higher temperatures.
Facile synthesis and characterization of functionalized, monocrystalline rutile TiO2 nanorods.
2006
Functionalized, monocrystalline rutile TiO2 nanorods were prepared from TiCl4 in aqueous solution under acidic conditions in the presence of dopamine, followed by aging and hydrothermal treatment at 150 degrees C. The surface-bound organic ligand controls the morphology as well as the crystallinity and the phase selection of TiO2. The presence of monocrystalline rutile TiO2 was confirmed by X-ray powder diffraction and HRTEM investigations. The as-prepared nanorods are soluble in water at pH3. The surface functionalization was analyzed by IR and 1H NMR, confirming the presence of dopamine on the surface. The surface amine groups can be tailored further with functional molecules such as dyes…
Partitioning of macrocyclic compounds in a cationic and an anionic micellar solution: a small-angle neutron scattering study.
2004
Following a previous investigation on partitioning of some macrocycle compounds in sodium dodecyl sulfate (SDS) and dodecyltrimethylammonium bromide (DTAB) aqueous solutions and their effect on the micellar structure, a small-angle neutron scattering (SANS) study has been performed at fixed surfactant content (0.20 mol/L) and varying macrocycle concentrations from 0.20 up to 1.0 mol/L. Conductivity measurements have been also performed in order to evaluate the effect of the presence of macrocycles on the critical micellar concentration (cmc) of the two surfactants. SANS experimental data were fitted successfully by means of a core-plus-shell monodisperse prolate ellipsoid model. It has been…
Thermodynamic and kinetic aspects of the transport of small molecules in dispersed systems
1998
Abstract The knowledge of the behaviour of flavour compounds in complex multiphase systems with regard to their structure is of great importance in flavour perception of foods. The thermodynamic and kinetic behaviour of three selected flavour compounds belonging to a homologous series of esters, e.g. ethyl acetate, ethyl butanoate and ethyl hexanoate, were studied in simple and multiphase systems. The liquid system was composed of water (with or without sodium caseinate) and/or a lipid, Miglyol. First, the properties of the solutes were determined by means of their liquid–liquid partition at equilibrium and their diffusion in aqueous or lipid phases. This first step allowed to reveal the im…
Extended Investigation of the Aqueous Self-Assembling Behavior of a Newly Designed Fluorinated Surfactant
2009
The physicochemical behavior of the newly synthesized fluorinated 5-hydroxyamino-3-perfluoroheptyl-1,2,4-oxadiazin-6-one (PFHO) surfactant was investigated. Thermal analysis showed that the pure surfactant is thermally stable under an inert atmosphere to 135 degrees C, which is several degrees higher than the melting point (99 degrees C). PFHO is rather active at the water/air interface where it assumes a standing up configuration. It exhibits an enhanced self-assembling behavior; accordingly, the critical micellar concentrations at some temperatures are 2 orders of magnitude lower than those of a similar surfactant having the same phobicity, such as sodium perfluorooctanoate. Even in the d…
Heat Capacity of Transfer of (Ethylene oxide)13-(propylene oxide)30-(ethylene oxide)13 from Water to the Aqueous Anionic Surfactant Solutions at 298 …
2004
Heat capacities of transfer (ACpt) of unimeric (ethylene oxide)(13)-(propylene oxide)(30)-(ethylene oxide)(13) from water to the aqueous surfactant solutions as functions of the surfactant concentrations (m(S)) were determined at 298 K. The surfactants investigated are sodium hexanoate, sodium heptanoate, sodium octanoate, sodium undecanoate, and sodium dodecanoate. For short alkyl chain surfactants, the profiles of the DeltaCp(t) versus ms curves show maxima and minima; for long alkyl chain surfactants, the maximum becomes sharper and moved to lower ms values whereas the minimum tends to disappear. These experimental trends are different from those of the enthalpy in agreement with the fac…