Sökning: "polycrystalline surfaces"
Visar resultat 6 - 10 av 20 avhandlingar innehållade orden polycrystalline surfaces.
6. Study of polycrystalline gold surfaces by potential-dependent optical sum frequency generation
Sammanfattning : With the increase in demand for renewable energy, the comprehension of chemical processes is essential to improve the design of catalysts in order to achieve better performance. This thesis summarizes the experimental investigation of redox reactions on polycrystalline gold surfaces by combining electrochemistry with operando surface-specific sum frequency generation (SFG) for a wider anodic potential interval than previously studied in acidic aqueous medium (H3PO4, pH 1). LÄS MER
7. 31 P- and 65 Cu- solid state NMR studies of Cu(I) di-alkyl-dithiophosphates : complex Formation Mechanism on Synthetic Chalcocite Surfaces
Sammanfattning : Alkyl substituted derivatives of dithiophosphoric acid are frequently used as collectors in froth flotation enrichment of copper sulfide ores. Due to interaction between Cu atoms at the surface and thiol collector molecules, a concomitant adsorption process occurs on the mineral surface. LÄS MER
8. Electrical Characterization of Novel Insulators in Metal-Insulator-Semiconductor Structures
Sammanfattning : This thesis comprises seven papers (A-G) and an extended introduction which puts them into context within a broader field of research. The papers deal with the electrical characterization of some different insulators and interfaces encountered within the realm of silicon based microelectronics. LÄS MER
9. Dipolar recoupling sequences in 13C and 31P nuclear magnetic resonance studies of mineral surfaces
Sammanfattning : Solid state magic angle spinning (MAS) 31P nuclear magnetic resonance (NMR) experiments, both cross polarization (CP) and dipole-dipole recoupling, were used as tools in the investigation of the reaction products at the surface of synthetic galena (PbS) mineral and O,O'-dialkyldithiophosphate potassium salts. Various dipole-dipole recoupling sequences have been tested on powder glycine-13C2 NMR and a polycrystalline powder sample of O,O'-diethyldithiophosphate2-Ni(II) to find one or several sequences suitable for the surface experiments. LÄS MER
10. An NMR synopsis of the coordination chemistry of copper(I) dithiophosphate clusters
Sammanfattning : The coordination chemistry of monovalent copper with O,O'- dialkyldithiophosphate chelating ligands (L = S2P(OR)2, R = alkyl) is presented by poly-nuclear clusters containing Cu4 (tetrahedral), Cu6 (trigonal antiprismatic) or Cu8 (cubic) cores where the ligands display a tri-metallic tri-connective coordination mode in the first two classes of structures (Cu4L4 and Cu6L6) and a tetra-metallic tetra-connective coordination pattern in the third class (Cu8L6(S)). In this work, the polycrystalline copper(I) O,O'-dialkyldithiophosphate (dtp) compounds - Cu4L4 (L = S2P(OiPr)2, Cu6L6 (L = S2P(OEt)2) and Cu8L6(S) (L = S2P(OR)2, R = Et, nPr, iPr, nBu, iBu and iAm) were synthesised and studied by 31P MAS and static 65Cu NMR spectroscopy. LÄS MER
