Search results for "COATINGS"
showing 10 items of 2386 documents
Synergistic effect of ligating and ionic functions, prearranged on a calix[4]arene.
2006
The covalent attachment of two CMPO-functions and two anionic Cosan groups to the narrow rim of tert-butylcalix[4]arene leads to a dramatic increase of the extraction efficiency for the cone isomer; Am(3+) is removed from 5 x 10(-8) M solution to more than 99% by a single extraction step with a 3 x 10(-6) M solution of the calixarene.
Extraction of lanthanides and actinides by a magnetically assisted chemical separation technique based on CMPO-calix[4]arenes
2001
A novel particulate system carrying CMPO ligands pre-organised on a calixarene scaffold has been synthesised and demonstrated to extract Eu3+, Am3+ and Ce3+ at high efficiency from simulated nuclear waste streams.
Energy distribution of plasma-assisted electron and ion emission from TGS single crystals
2008
Abstract Electron and ion emission accompanying non-thermal plasma processes, produced at the surface of TGS single crystals under driving ac electric field exceeding 10 3 V/cm, have been carried out. These plasma-assisted emission of electrons and ions were examined by means of time and energy distribution measurements. The intensity of registered charges (electrons and ions) displayed on the 2 ms time scale are represented by two distinct peaks. Time dependent energy spectrum of charges, detected under our experimental conditions, involves electrons and ions with maximum energy up to 30–40 eV for first peaks and up to 70–80 eV for second one. Additionally, the energy of electrons is focu…
Hartree–Fock study of adhesion and charge redistribution on the Ag/MgO(0 0 1) interface
2001
Abstract Ab initio study of the Ag/MgO(0 0 1) interfaces based on a quantitative analysis of the bonding in the interfacial region is provided in the framework of Hartree–Fock approach. We are describing the way interfacial electronic and other properties evolve as a function of metal coverage. General conclusion that could be drawn from our calculations is that chemical bond formation is not important for the Ag/MgO(0 0 1) perfect interface. Physisorption of Ag atoms over surface O 2− ions associated with atomic polarization and charge redistribution in the metal planes are the dominant effects. The adhesion energy is enhanced by the interaction of the substrate Mg 2+ ions with the surplus…
Folding and dimerization of resorcarene tetrasulfonates
2001
In the solid state and in CDCl3 resorcarene tetramesitylsulfonates fold by intramolecular SO⋯H–O hydrogen bonds and dimerise via intermolecular O–H⋯OH hydrogen bonding.
Intense laser effects on donor impurity in a cylindrical single and vertically coupled quantum dots under combined effects of hydrostatic pressure an…
2010
WOS: 000280235800010
Role of the central gold atom in ligand-protected biicosahedral Au 24 and Au25 clusters
2013
The crystal structures of the ligand-protected clusters [Au24(PPh3)10(SC2H4Ph)5Cl2]+ and [Au25(PPh3)10(SC2H4Ph)5Cl2]2+ have been elucidated recently, and they comprise the same biicosahedral structural motif for the Au core. The only difference is the central Au atom joining two icosahedra which is absent in the Au24 cluster. On the basis of density functional simulations, we have evaluated the structural, electronic, optical, and vibrational properties of the clusters in question with a full presentation for the thiolate and phosphine side groups. Our spherical harmonics analysis of the electronic structure shows that the chemical stability of both clusters can be understood based on an 8 …
Adsorption of 3d Transition Elements on a TiO2(110) Surface.
2008
International audience; A first-principles study on the adsorption of 3d transition metal atoms on a stoichiometric TiO2(110) surface is reported. For all 3d elements except Cu, the most stable on-surface adsorption site is a site where the adatom binds to two twofold and one threefold surface oxygen atoms. For Ti, V, and Cr, however, a subsurface site, where the adatom substitutes a sixfold Ti atom, is more stable. The adatoms are oxidized in all cases. The charge transfer to the substrate is larger for the substitutional site than for the on-surface adsorption sites and decreases with atomic number along the 3d series. The relative stabilities of the adsorption sites are discussed in term…
First principles slab calculations of the regular Cu/MgO(001) interface
2004
Ab initio slab calculations are performed for the copper adhesion over magnesium ions on the perfect MgO(0 0 1) surface with 1/4 monolayer (ML), two types of 1/2 ML and 1 ML substrate coverages. Results of our calculations are compared with various experimental and theoretical data. Both small atomic polarization and charge redistribution give the dominant contributions to the physisorption bonding on a regular Cu/MgO(0 0 1) interface.
Intrinsic Metal Size Effect on Adsorption of Organic Molecules on Platinum
2008
Di-σ adsorbed ethene, bridge(30) adsorbed benzene (with four di-σ-type and two π-type interactions), and η1 and η2 adsorbed acetone on nanosized platinum clusters consisting of 19 to 38 Pt atoms were studied theoretically by density functional theory (DFT) calculations with general gradient approximation (GGA) utilizing plane wave and local basis sets. The cluster results were compared to plane wave calculations employed with periodic boundary conditions. It was found that the geometries obtained with different methods are very similar but the adsorption energy depends prominently on the cluster size. Adsorption was strongest on the 22- and 26-atom clusters and weakest on the 35- and 38-ato…