Sökning: "solid state-NMR"

Visar resultat 16 - 20 av 45 avhandlingar innehållade orden solid state-NMR.

  1. 16. 31 P- and 65 Cu- solid state NMR studies of Cu(I) di-alkyl-dithiophosphates : complex Formation Mechanism on Synthetic Chalcocite Surfaces

    Författare :Daniela Rusanova; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry of Interfaces; Gränsytors kemi;

    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

  2. 17. Evaluation of NMR Knight shifts in metallic nanoparticles and topological matter

    Författare :Wassilios Papawassiliou; Andrew Pell; Niklas Hedin; Ulla Gro Nielsen; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; solid-state NMR; Knight shifts; metallic systems; topological matter; nanoparticles; DFT calculations; Physical Chemistry; fysikalisk kemi;

    Sammanfattning : Elucidating the surface electron states of transition metal compounds is of primary importance in main heterogeneous catalytic processes, such as the hydrogen and oxygen evolution reactions.  Key property in all these processes is the position of the energy of the d-band center relative to the Fermi-level of the catalyst; it must be shifted close to the Fermi level to achieve balance between adsorption and desorption of the catalyst and the adsorbate. LÄS MER

  3. 18. Molecular orientation in cellulose fibers and composites

    Författare :Leo Svenningsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; composite; molecular orientation; lignin; solid-state NMR; Raman spectroscopy; fibers; X-ray scattering; carbon fibers; regenerated cellulose;

    Sammanfattning : The scope of this thesis is to quantitatively investigate the molecular orientation distribution of regenerated cellulose fibers and composites. The molecular orientation is known to affect macroscopic properties such as tensile strength of the fiber. LÄS MER

  4. 19. Molecular mass distribution of cellulose from steam-exploded aspen wood

    Författare :Tomas Josefsson; KTH; []
    Nyckelord :Steam-explosion; Populus tremula; Molecular mass distribution; Size exclusion chromatography; Solid state NMR; Lignin; Cellulose; Xylan; Carbohydrate degradation;

    Sammanfattning : .... LÄS MER

  5. 20. Concentrated DNA-amphiphiles Structure, Hydration, and Dynamics

    Författare :Cecilia Leal; Fysikalisk kemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; amphiphiles; DNA; Physical chemistry; diffusion NMR; solid-state NMR; electrostatics; dynamics; local order; Fysikalisk kemi; hydration;

    Sammanfattning : The structure, hydration, and dynamics of concentrated DNA-amphiphile complexes were investigated by small-angle X-ray diffraction, sorption calorimetry, and nuclear magnetic resonance. A concentrated, electroneutral, DNA-amphiphile complex can be formed by mixing charge-stoichiometric solutions. LÄS MER