Search for dissertations about: "Oppositely charged polymer-surfactant systems"

Found 5 swedish dissertations containing the words Oppositely charged polymer-surfactant systems.

2. 1. Versatile Association Behavior in Mixtures of Oppositely Charged Amphiphiles : From DNA-Like Assembly of Supramolecular Helices to Coacervation in Chiral Surfactant Systems

   Author : Guanqun Du; Fysikalisk kemi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Bile salts; Block copolymers; Oppositely charged polymer-surfactant systems; Co-assembly; BS sequestrants; Gemini surfactants; Supramolecular helices; Hexagonal packing; Chirality; Thermoresponsive behavior; Scattering; Tomography; Calorimetry;

   Abstract : As biological surfactants, bile salts (BSs), play important roles in biological processes, i.e., food digestion, but also in BS-related diseases, as well as in applications. READ MORE

4. 2. Phase Behavior and Solution Properties of Aqueous Polyion-Surfactant Ion Systems

   Author : John Janiak; Fysikalisk kemi; []
   Keywords : 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;

   Abstract : 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). READ MORE

5. 3. Associative Polymer-Polymer and Polymer-Surfactant Systems: Phase Behaviour and the Influence of Chemical Reactions

   Author : Salome Santos; Fysikalisk kemi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : Aqueous mixtures of two non-ionic polymers, poly(acrylic acid) (PAA) and the amphiphilic triblock copolymer, (EO)27(PO)67(EO)27, known by its trade name Pluronic® P104, showed an associative phase separation (miscibility gap), which decreased with the decrease of PAA length. It was found that PAA is a much less selective “solvent” to P104 molecules than water. READ MORE

6. 4. Surfactant Responsive Cross-Linked Polymer Hydrogels

   Author : Jesper Sjöström; Research Policy Institute (RPI); []
   Keywords : 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;

   Abstract : 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). READ MORE

7. 5. Association Phenomena Involving Hydrophobically Modified Polymers. Electrostatic and Hydrophobic Contributions

   Author : Marina Tsianou; Fysikalisk kemi; []
   Keywords : 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;

   Abstract : 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. READ MORE