Sökning: "self-diffusion coefficients"
Visar resultat 1 - 5 av 14 avhandlingar innehållade orden self-diffusion coefficients.
1. NMR Self-Diffusion Studies and Stability Studies of Emulsions
Sammanfattning : The aim of this study is to characterize emulsion systems by self-diffusion PGSE NMR methods. The specifics of the emulsions studied are all taken from the literature and they are of the W/O or O/W type stabilized with different emulsifiers. LÄS MER
2. Nuclear magnetic resonance studies of water self-diffusion in porous systems
Sammanfattning : Proton nuclear magnetic resonance (NMR) was used to study the self-diffusion of water in porous systems that respond to a change in water content in order to elucidate the porous structure and the properties of the confined water. In the carbohydrate systems cellulose fibers and starch granules, water is free to move throughout the porous objects, albeit with a rate reduced from the value of the bulk liquid, The reduction is related to the tortuosity of the pore space filled by water. LÄS MER
3. Water diffusion and free volume in hydrophilic polymers
Sammanfattning : During moisture uptake in polymers, the diffusion of the water molecules is believed to occur via unoccupied voids. These voids are called free volume cavities and their sizes are continuously altered when the moisture content in the polymer is enhanced. LÄS MER
4. Association Phenomena in Aqueous Solutions of Surfactants and Hydrophobically Modified Polymers
Sammanfattning : Interactions between ionic surfactants (sodium dodecyl sulfate and dodecyltrimethylammonium chloride) and nonionic polymers ((hydroxyethyl)cellulose, ethyl(hydroxyethyl)cellulose and their hydrophobically modified analogous) have been studied by means of rheology, pulsed field gradient nuclear magnetic resonance (PFG NMR), time-resolved fluorescence quenching (TRFQ), dynamic light scattering (DLS) and cryo-transmission electron microscopy (cryo-TEM). In all experiments surfactants have been added in various amounts to polymer solutions at fixed concentrations. LÄS MER
5. Physico-Chemical Properties of Plant Polysaccharides Investigated with NMR Techniques
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