Sökning: "Dilute"

Visar resultat 41 - 45 av 195 avhandlingar innehållade ordet Dilute.

1. 41. 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

3. 42. Solution properties of a hydrophobically modified polymer

   Författare :Krister Thuresson; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; sodium dodecylsulfate; surfactants; fluorescence; light scattering; NMR; rheology; cloud point; phase behaviour; polyelectrolytes; ethyl hydroxyethyl cellulose; hydrophobically modified; water soluble polymers; aggregation number; association; Physical chemistry; Fysikalisk kemi;

   Sammanfattning : The influence of hydrophobic modification on solution properties of water-soluble polymers in the semi-dilute regime have been studied. The nonionic ethyl(hydroxyethyl)cellulose (EHEC) and its hydrophobically modified analogue (HM-EHEC) are used as model substances. LÄS MER

4. 43. Structural Changes in Nonionic Surfactant Systems

   Författare :Sanja Bulut; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Vesicles; Nonionic Surfactant; Wormlike Micelles; Lamellar Phase; NMR; MRI; SLS; DLS; cryo-fracture-TEM; centrifugation; cryo-TEM;

   Sammanfattning : In this thesis we have studied structural changes of a nonionic surfactant self-assembly, as governed by changes in temperature and concentration. The techniques used in experimental investigations were dynamic and static light scattering, nuclear magnetic resonance and cryo-transmission electron microscopy (using a novel specimen preparation protocol). LÄS MER

5. 44. Association and Microstructure in Self-Assembling Catanionic Systems

   Författare :Eduardo Marques; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PFG NMR self-diffusion; cryogenic-transmission electron microscopy; catanionic systems; gels; bile salts; polyelectrolytes; liquid crystals; vesicles; Surfactants; phase diagrams; light microscopy; Theoretical chemistry; quantum chemistry; Teoretisk kemi; kvantkemi;

   Sammanfattning : This thesis addresses the phase behavior and phase structure in mixed surfactant-surfactant and surfactant-polymer systems, where the co-solutes have opposite charges (catanionic systems). The initial goal has been to investigate self-assembly aspects in mixtures of single-/double-chained surfactants and bile salt/double-chained surfactants, with the main focus on vesicle assembly in dilute regions. LÄS MER

7. 45. Pretreatment and enzymatic saccharification of lignocellulose : formation and effects of pseudolignin

   Författare :Monica Normark; Leif Jönsson; Sandra Winestrand; Torbjörn Lestander; Wilfred Vermerris; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Pretreatment; enzymatic saccharification; ionic liquid; torrefaction; pseudolignin; Analytical Chemistry; analytisk kemi;

   Sammanfattning : Production of advanced biofuels, green chemicals, and bio-based materials from renewable lignocellulosic biomass would contribute to decreased dependence on fossil resources and to sustainable development. The overall aim of the investigations was to explore how preprocessing and pretreatment technologies affected the chemical composition of cellulosic materials and their susceptibility to enzymatic saccharification, which is one of the major routes for biorefining of lignocellulose. LÄS MER