Sökning: "Surfactant"

Visar resultat 11 - 15 av 338 avhandlingar innehållade ordet Surfactant.

1. 11. NMR Diffusion Studies of Association in Surfactant Systems Inclusion Complexes, Micellar Solutions and Microemulsions

   Författare :Markus Nilsson; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; host-guest complexation; gemini surfactant; cyclodextrin; bolaform surfactant; self-diffusion NMR; pluronic; bicontinuous microemulsion; polydispersity; boosting effect;

   Sammanfattning : The aim of this thesis has been to investigate self-diffusion behavior of host-guest complex, microemulsion and polymer solution. Pulsed Field Gradient NMR (PFG-NMR) was shown to provide detailed molecular information in all system studied. LÄS MER

3. 12. 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

4. 13. Polyelectrolyte - Surfactant Interactions in Dilute Suspensions. A Study Based on Monte Carlo simulations and Mean-Field Calcultations

   Författare :Torsten Wallin; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; aggregation number; linear charge density; chain flexibility; mean-field; calculation; simulation; Monte Carlo; cmc; cac; interaction; electrostatic; charged; micelle; polyelectrolyte; surfactant; hydrophilic; hydrophobic; Physical chemistry; Fysikalisk kemi;

   Sammanfattning : The complexation of macroions or charged micelles and oppositely charged polyelectrolytes was studied by the use of Monte-Carlo simulations and mean field calculations. The Monte-Carlo simulations were performed on a simple model system with the emphasis on the electrostatic interaction, (i) polyelectrolyte rigidity, (ii) polyelectrolyte linear charge density, (iii) surfactant tail length, and (iv) the polyelectrolyte concentration. LÄS MER

5. 14. Phase Behavior and Solution Properties of Aqueous Polyion-Surfactant Ion Systems

   Författare :John Janiak; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Polymer-surfactant association; complex salt; nonionic surfactant; poly acrylic acid ; poly methacrylic acid ; copolymer; polymeric counterion; decyl betainate; phase behavior; solubilization; mixed micelle; hydrolysis; release; liquid crystal; nanoparticles; thermosresponsive; C12E8; C12E5;

   Sammanfattning : Polyelectrolytes and oppositely charged surfactants interact through attractive electrostatic forces, which in many cases lead to phase separation already at low total concentrations. During the past 10-15 years investigations of these systems have been simplified through the use of complex salts that consist of surfactants with polymeric counterions in a 1:1 charge stoichiometry (no excess simple counterions present). LÄS MER

7. 15. Surfactant Responsive Cross-Linked Polymer Hydrogels

   Författare :Jesper Sjöström; Research Policy Institute (RPI); []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; Fysikalisk kemi; Two-step binding isotherms; Resolubilization; Nonmonotonic transient volume changes; Swelling isotherms; Divinyl sulfone DVS ; Polyquaternium; Cellulose ethers; Amphiphilic cross-linked polymers; Responsive gels; Polymer-surfactant interactions;

   Sammanfattning : The focus of the thesis is on chemically cross-linked hydrogels which drastically change their volume when immersed in solutions of different ionic surfactants (with or without added salt). The two main questions addressed are: (1) How useful are simple gel swelling experiments to the study of polymer-surfactant interactions?, and (2) How does the volume of a cross-linked polymer gel change when it is immersed in a surfactant solution, both with respect to the equilibrium swelling and with respect to transient volume changes? Most of the gels studied were prepared by cross-linking linear polymers, which were well studied derivatives of hydroxyethyl cellulose (HEC). LÄS MER