Sökning: "PT ssNMR"

Hittade 4 avhandlingar innehållade orden PT ssNMR.

  1. 1. Foreign molecules in biomembranes : Molecular effects on intact stratum corneum and model lipid systems

    Författare :Quoc Dat Pham; Fysikalisk kemi; []
    Nyckelord :stratum corneum; lipid; keratin filament; protein; DMPC; penetration enhancer; osmolyte; solvent; monoterpene; fatty acid; hydration; molecular mobility; fluidity; permeability; PT ssNMR; diffusion cell;

    Sammanfattning : This thesis mainly explores how the molecular mobility of lipid and protein components in the outermost layer of the skin, the stratum corneum (SC), varies with different conditions and upon adding foreign compounds. These studies require methods that makes it possible to detect and characterize the minor amount of fluid components in the highly ordered solid SC sample with resolved molecular information. LÄS MER

  3. 2. Polarization transfer solid-state NMR for studying soft matter: From surfactants to the stratum corneum

    Författare :Agnieszka Nowacka; Fysikalisk kemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The work presented in this thesis is dedicated to theoretical development, experimental testing and application of polarization transfer solid-state nuclear magnetic resonance (PT ssNMR). PT ssNMR is an analytical tool which provides detailed information about molecular mobility in model or simple soft matter systems at the low water content regime, enabling the creation of phase diagrams. LÄS MER

  4. 3. The Co-Structure Directing Agent (CSDA) Approach to Mesoporous Silica Formation – Exploring the Assembly Characteristics

    Författare :Ruiyu Lin; Fysikalisk kemi; []
    Nyckelord :mesoporous silica materials; co-structure directing agent; surfactants; mesostructures; scattering; NMR; TEM;

    Sammanfattning : We investigate the formation mechanism responsible for two specific systems of mesoporous silicas formed with the so-called co-structure directing agent (CSDA) route. The synthesis relies on the interactions between silica source (tetraethylorthosilicate, TEOS), surfactants and CSDA. LÄS MER

  5. 4. 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