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The effect of changing the fraction of charged monomer units of the polyion in aqueous polyion-oppositely charged surfactant complex salts is examined. It is shown that the average surfactant aggregation number in the surfactant aggregates has decreased when the fraction of charged monomers is decreased.

The effect of hydrophilically modified polystyrene, poly(styrene-g-poly(ethylene oxide)), P(S-g-PEO), on the viscosity of AOT oil-continuous microemulsions is investigated as a function of PS and PEO chain lengths and PEO chain density.

The simplest possible mixtures, with a reduced number of components, compared to conventional polyelectrolyte-surfactant mixtures, were used to study the factors that control the structure and water solubility of aggregates of oppositely charged polymers and surfactants. The study confirmed that the identity of the simple monovalent counterion might be important for the structure and solubility of surfactant aggregates with mixed polymeric and simple counterions.

Issues concerning the impact of a graft copolymer on the phase boundary between the oil-continuous microemulsion and the two-phase area of the ternary phase diagram of AOT, water and cyclohexane are discussed. The graft copolymer is soluble in the microemulsion but not in pure water or in pure cyclohexane.

The phase behaviors of the ether ethyl(hydroxyethyl)-cellulose (EHEC), a lower consolution temperature (LCST) polymer, and its hydrophobically modified analogue (HMEHEC), were examined by determining the cloud point curve. The cloud point and coexistence curves for the quasi-binary water systems and the quasi-ternary systems were determined by pouring minute amounts of the anionic surfactant, sodium octylbenzenesulfonate. It was observed that HMEHEC had a lower cloud point than the EHEC. The cloud point curves of the water systems exhibited weaker concentration reliance.

The phase separation of aqueous systems consisting of sodium polyacrylate and the surfactant cetyltrimethylammonium bromide was investigated. Experimental results showed that the aqueous systems can separate into a concentrated phase and a dilute phase, and this separation can be induced by the addition of water. Adding more water causes the concentrated phase to become more concentrated. It was also found that the surfactant ions are always aggregated into elongated micelles.

Cetyltrimethylammonium surfactants with a range of oligo carboxylate counteranions are synthesized and the phase behavior of all binary surfactant/water mixtures is examined. The addition of decanol has given rise to a second birefringent phase in equilibrium with the lamellar phase.

An examination of the phase behavior of ternary mixtures containing an alkyltrimethylammonium polyacrylate complex salts, water, and a nonpolar 'oil' (n-decanol, p-xylene or cyclohexane) is done to get a complete picture on how various oils are included into assemblies of complex surfactant salts with polymeric counterions, and their resultant impact with regards to structural changes. Results indicate a much more limited swelling of the lamellar phases within polymeric counterions by water which is prominently attributed to bridging due to the polyions.

The aqueous phase behavior of a series of complex salts, containing cationic surfactants with polymeric counterions is investigated by visual inspection and small-angle X-ray scattering. The investigated set of complex salts, involving five different surfactant chain lengths and two polyion lengths is shown to confirm to a consistent picture.

Patterns in the interaction of cationic surfactants with nonionic polymer gels, which were inferred from a study, are confirmed by measurements of a series of alkylammonium surfactants with different counterions with a series of alkyl acrylamide gels of increasing hydrophobicity. Two swelling patterns were observed and the binding studies confirmed that the amount of surfactant bound depends on the counterion in cases where saturation binding is not reached but not in cases where saturation binding is reached.

A systematic study of the dissolution of dry, polydisperse poly(ethylene oxide) (PEO) samples, obtained from mixtures of low-molecular-weight and high-molecular-weight PEO, is described. The findings indicate that the low-molecular-weight/ high-molecular-weight ratio controls the release rate, and the fraction of high-molecular-weight polymers dominates the effect on the overall release rate in mixed PEO tablets.

The interactions between charged alkylacrylamide gels of varying hydrophobicity and charge density, and the oppositely charged surfactant hexadecyltrimethylammonium are investigated. The results obtained were used to determine the conditions necessary to induce excess surfactant binding and resolubilization of the polymer-surfactant complex.

Gel swelling experiments are used to study the binding of ionic surfactants to a series of nonionic alkylacrylamide hydrogels of increasing hydrophobicity. The binding of hexadecyl trimethylammonium to uncharged gels is sensitive to both the hydrophobicity of the gel and the counterion to the surfactant.

The effect of changing the block lengths of triblock copolymers of poly(ethylene oxide)-polystyrene-poly-(ethylene oxide) (PEO-PS-PEO) on the relative viscosity of AOT oil-continuos microemulsions, with cyclohexane as the oil, was investigated. The viscosity behavior of the PEO-PS-PEO microemulsion system is explained.

The effects of different molecular weight polystyrenes (PS) on the phase behavior of sodium 1,4-bis(2-ethylhexyl) sulfosuccinate (AOT)/water/cyclohexane oil-continuous microemulsions are investigated. The polymer-particle segregation in this well-defined system is studied where both polymer size, particle size, and hence size ratio could be controlled and where polymer-solvent interactions could be varied across the theta temperature.

The use of cryo-transmission electron microscopy in an attempt to visualize the structures formed in aqueous mixture of amylose (AM) and surfactant sodium dodecyl sulfate (SDS) is presented. It is concluded that the vesicles consist of AM-SDS complexes.

The molecular self-diffusion in concentrated aqueous mixtures based on an oppositely charged polymer-surfactant pair is studied by NMR pulsed field gradient techniques. It is reported that it is now possible to measure the diffusion coefficients of all molecular species over the entire composition range of monovalent/polymeric counterions.

The interactions of sodium dodecyl sulfate (SDS) with chemically cross-linked gels of ethyl (hydroxyethyl) cellulose (EHEC) were studied. The binding of SDS to the gels was measured with flame emission analysis of the sodium ion. The self-diffusion of the surfactant ion (DS) in the gels was studied by the NMR pulsed field gradient spin-echo technique. Both the experiments were performed on gels swollen to equilibrium in SDS solutions of varying concentrations.

Polyelectrolytes 2002 meeting, which was held in Lund, Sweden, was the fourth in a series of International Symposia on Polyelectrolytes (ISP) that began in 1995. Bringing together the scientists working in the field of polyelectrolytes, a subject that is relevant to problems in biology, in the development of new materials, and in numerous industrial applications, was the mission of the ISP organization.