Sökning: "Mineral Chemistry"
Visar resultat 21 - 25 av 166 avhandlingar innehållade orden Mineral Chemistry.
21. 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
22. Reactions at the water-mineral interface of olivine and silicate modified maghemite
Sammanfattning : The main objectives for this licentiate thesis have been to study and model the reactions at the water-mineral interface of two subsystems: maghemite-H+-silicate and olivine-H+. An increased knowledge of these systems will make it possible to further extend the complexity of the aqueous phase in future experiments. LÄS MER
23. 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
24. Coordination Chemistry of Monocarboxylate and Aminocarboxylate Complexes at the Water/Goethite Interface
Sammanfattning : This thesis is a summary of five papers with focus on adsorption processes of various monocarboxylates and aminocarboxylates at the water/goethite interface. Interaction of organic acids at the water/mineral interfaces are of importance in biogeochemical processes, since such processes have potential to alter mobility and bioavailability of the acids and metal ions. LÄS MER
25. Advances in Separation Science : . Molecular Imprinting: Development of Spherical Beads and Optimization of the Formulation by Chemometrics
Sammanfattning : An intrinsic mathematical model for simulation of fixed bed chromatography was demonstrated and compared to more simplified models. The former model was shown to describe variations in the physical, kinetic, and operating parameters better than the latter ones. LÄS MER
