Polyelectrolyte gel-surfactant

A surprising result was obtained for both cationic gel-anionic surfactant systems The metal-containing samples appear not less ordered than the initial polyelectrolyte gel-surfactant complexes despite the diminished amplitudes of the peaks. For the PDADMACl-SDBS system, the average distance between... 

As can be seen from the discussion above, the polyelectrolyte gel-surfactant complexes present interesting hybrid metal-polymer nanocomposites, allowing a vast variety of incorporated metals and metal-polymer-surfactant structures. The limitations of these systems are their heterogeneous character (insoluble in any media) and excessive sensitivity to external parameters (pH, temperature, etc.). 

It has been shown that the exchange of counter ions for the ions of a surfactant can induce a sharp collapse of the polyelectrolyte gel. Simultaneously, a very effective absorption of surfactants from the solution is observed. Complexes of the networks with surfactants possess the ability to solubilize different organic substances. The later fact is of important practical interest, for example for removing surfactants and impurities from water. 

Ionic microgel particles play an important part in studies of the phase transition, as we will learn in Sec. V. In cases of NIPA-based polymerization systems, submicron-sized polyelectrolyte gel particles can easily be prepared using the usual synthetic technique of aqueous redox polymerization. Different polymerization media were then employed surfactant-containing wa-... 

We can convert neutral NIPA gels into a polyelectrolyte gel through the binding of surfactant molecules such as sodium dodecylbenzene sulfonate (NaDBS) and sodium dodecyl sulfate (SDS) [20], As will be seen in Sec. V.B, the polyelectrolyte gel of this sort provides us with important infor-... 

Urea, being a water structure breaker, would weaken the hydrophobic interaction between solute molecules as reported in several previous studies (see Ref. 76). It is thus necessary for us to examine the effects of urea on the hydrophobic interaction in the present gel system. However, this is a considerably difficult problem which, to our knowledge, has not yet been dealt with by any researchers in the field of polyelectrolyte gels. The main reason is the lack of information about whether hydrophobic interaction plays a role in the volume collapse of usual polyelectrolyte gels with a lot of hydrophilic ionizable groups, such as the LPEI gels in question. As a novel approach in order to overcome this difficulty, we examined the swelling curves of the LPEI gel as a function of the concentration of anionic surfactants in the presence and absence of urea. 

Hirata M, Yamada Y, Kokufuta E. Effects of pH and alkyl sulfate surfactants on swelling equilibria for a cationic polyelectrolyte gel from poly-(ethyleneimine). In Schmitz K, ed. Macro-ion Characterization from Dilute Solutions to Complex Fluids. ACS Symp Ser, No 548. Washington DC Amer Chem Soc, 1994 493-498. 

Among solid polymer nanostructures, two types of systems will be described (a) complexes of polyelectrolyte gels with surfactants and (b) crosslinked polymers containing nanopores or nanocavihes. 

Gels sensitive to electric field were also obtained using the process of reversible complex formation between a polyelectrolyte gel and an oppositely charged surfactant. The complex formation is accompanied by surfactant ion aggregation to micelles, which results in gel contraction at the site of complexation (Figure 22). By using an electric field to direct surfactant binding selectively to one side of the gel, one can induce contraction and curvature of a strip of gel. ° ... 

Olga E. Philippova s main research interests are polyelearolyte and ionomer behavior of polymer gels, linear and cross-linked polyelectrolytes with associating hydrophobic groups, polymer gel/surfactant interactions, interpolymer complexes, and polymer gels with entrapp l linear stiff-chain macromolecules. 

Our list of future directions cannot be complete without mentioning polyelectrolyte gels, polyelectrolyte brushes [192-195] (polyelectrolytes grafted to a surface), and complexation of polyelectrolytes with colloids [196-200], dendrimers [201], surfactants, and proteins. We anticipate serious... 

Association and dissociation of polyelectrolyte gel of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) with cationic surfactant was found to undergo worm-like motility in aqueous solution. 

Highly Ordered Supramolecular Structures from Self-Assembly of Ionic Surfactants in Oppositely Charged Polyelectrolyte Gels... 

When a highly swollen polyelectrolyte gel is immersed in an aqueous solution of a surfactant, the volume of the gel suddenly shrinks. Further, if a hydrophobic gel that does not swell in water is placed in the same solution, the gel swells. These phenomena are caused by the adsorption of the surfactant onto the gel. The adsorption of the surfactant onto the gel is caused by static interaction (when it is a polyelectrolyte gel) or hydro-phobic interaction. Gels can change from hydrophilic to hydrophobic and vice versa by interacting with surfactant molecules. As a result, the properties of the gel change drastically. There are many reports on the interaction between surfactants and linear polymers [26-29]. A Russian group reported on work on three-dimensionally crosslinked polymer gels [30-32], Later, other authors developed a worm-like device that moves... 

Polyelectrolyte gels with strong static potential also adsorb ionic sur ctant with opposite charge. Figure 3 shows the adsorption isotherms of die cationic surfactant, N-dodecylpyridinium chloride (C]2PyCl), on the anionic polymer gel, poly (2-acrylamide-2-methylpropanesulfonic acid) (PAMPS). This figure is compared with the corresponding linear polymer solution [38]. 

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