Sökning: "phase association"

Visar resultat 1 - 5 av 243 avhandlingar innehållade orden phase association.

1. 1. Association Phenomena Involving Hydrophobically Modified Polymers. Electrostatic and Hydrophobic Contributions

   Författare :Marina Tsianou; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; scaling; light scattering; rheology; aqueous solution behavior; phase behavior; cyclodextrin; surfactant; polyacrylate; cellulose ether; polyelectrolyte; hydrophobically modified polymer; Polymer; water soluble polymer; viscosity; association; segregation; Physical chemistry; Fysikalisk kemi;

   Sammanfattning : The electrostatic and hydrophobic interactions in aqueous solutions of hydrophobically-modified water-soluble non-ionic or ionic polymers, their mixtures with a second polymer, nonionic or of opposite charge, and their mixtures with surfactants of opposite charge have been investigated. The relative strength of the electrostatic and hydrophobic contributions has been modulated by a variation of the polymer charge density and the solution pH, and by a variation in the degree and strength of the hydrophobic modifications, respectively. LÄS MER

3. 2. 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. 3. 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

5. 4. Characterisation of Aqueous Solutions, Liquid Crystals and Solid State of Non-ionic Polymers in Association with Amphiphiles and Drugs

   Författare :Annika Ridell; Martin Malmsten; Sven Engström; David Attwood; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; polymer; surfactant; phase diagram; x-ray diffraction; fluorescence spectroscopy; calorimetry; PEG; cellulose ether; viscometry; cubic phase; liquid crystals; drugs; solid dispersion; Fysikalisk kemi; Physical chemistry; Fysikalisk kemi; Fysikalisk och oorganisk farmaceutisk kemi; Physical and Inorganic Pharmaceutical Chemistry;

   Sammanfattning : Cellulose ethers and polyethylene glycols are used in drug formulations as water swelling or water soluble matrices. Polar lipids, for example monoglycerides, and surfactants can be used to solubilise hydrophobic or amphiphilic drugs and to formulate potential drug delivery vehicles such as emulsions, liposomes and cubic phases. LÄS MER

7. 5. Molecular Association Studied by NMR Spectroscopy

   Författare :Lars Nordstierna; István Furó; Peter Griffiths; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NMR; spin relaxation; self-diffusion; intermolecular cross-relaxation; chemical shift; fluorinated surfactants; hydrogenated surfactant; micelle; non-ideal mixing; adsorption; hydration; surfactant-protein association; Physical chemistry; Fysikalisk kemi;

   Sammanfattning : This Thesis presents studies of molecular association in aqueous solution and at the liquid/solid interface. The investigated molecular systems range from self-aggregating surfactants to hydration water in contact with micelles or individual molecules. In most studies, combinations of various NMR methods were applied. LÄS MER