Sökning: "pulsed field gradient"

Visar resultat 1 - 5 av 24 avhandlingar innehållade orden pulsed field gradient.

  1. 1. Pulsed Field Gradient NMR Studies of Diffusion in Polymer Gels

    Författare :Diana Bernin; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; diffusion; gel; alginate; pulsed field gradient NMR; 19F NMR; cellulose; 1H NMR; dendrimer; biomaterial; mass transport;

    Sammanfattning : Soft biomaterials, such as gels, play an important role in different kinds of products and applications, in particular in drug delivery systems, health care products, and food. Polymer gel's great ability to control mass transport is applied on e.g. the uptake of liquids in diapers. LÄS MER

  3. 2. NMR diffusion studies on lyotropic liquid crystalline systems

    Författare :Greger Orädd; Frank Volke; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Diffusion; pulsed field gradient; liquid crystalline systems; lipid lateral diffusion; cubic phases; peptide-lipid interactions; hydrophobic mismatch; permeability;

    Sammanfattning : The pulsed field gradient fourier transform nuclear magnetic resonance (PFG-FTNMR) method to measure translational diffusion coefficients in multicomponent systems has been applied to amphiphilic molecules forming liquid crystalline phases.By analyzing the concentration dependence of the diffusion coefficients of water and amphiphile in a micellar system of N,N-dimethyldodecy lamine oxide (DDAO) in water it was possible to conclude that the micelles formed were polydisperse in size and shape. LÄS MER

  4. 3. Molecular Interactions Studied by Electrophoretic and Diffusion NMR

    Författare :Fredrik Hallberg; Peter Stilbs; István Furó; Gareth Morris; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; NMR; electrophoretic NMR; Ion pairing; complexation; association; diffusion; pulsed field gradient; Nafion; Spectroscopy; Spektroskopi;

    Sammanfattning : Even though electrophoretic NMR (eNMR) experiments may provide unique chemical information and have been performed for three decades, the technique is still rarely applied, mainly because several experimental sources of artifacts have to be controlled to achieve accurate results. In this thesis, new experimental setups and protocols for accurate and precise eNMR experiments are presented. LÄS MER

  5. 4. Generic Properties of Polymer Solutions

    Författare :Takashi Uematsu; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; photon correlation spectroscopy; collective diffusion; atomic force microscopy; relaxation; agarose gel electrophoresis; DNA; Zimm dynamics; pulsed-field gradient NMR; superdiffusion; polymer solution; blob model; gel;

    Sammanfattning : Polymer solutions are abundantly present in our daily life, for example in paints, jellies, contact lenses and even in the living cells. Despite their ubiquity, we still have a poor understanding of the physical properties of solutions due to the extremely large number of internal degrees of freedom. LÄS MER

  7. 5. Physico-Chemical Properties of Plant Polysaccharides Investigated with NMR Techniques

    Författare :Åsa Östlund; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NMR diffusometry; Dissolution of cellulose; Chemical shift imaging; Fiber hornification; Xylan; Molecular weight; Pore size distribution; Cryoporometry; Cellulose solution; 19F NMR; Gelation of cellulose; Self-diffusion; Pulsed field gradient NMR; TBAF DMSO; 1H NMR;

    Sammanfattning : In the lead of developing new biomaterials from plant sources it is of importance to be able to control and vary the properties, such as flexibility, strength, and hygroscopicity of the final material. These properties are highly directed by the interactions between constituents on a molecular level. LÄS MER