Polymer-surfactant systems, phase

Piculell L., Lindman B., Karlstrom G. Phase behavior of polymer-surfactant systems. In Kwak J. C., ed. Polymer-Surfactant Systems. Surfactant Science Series 77. New York Marcel Dekker, 1998 66-141. 

The Polymer, Surfactant, Salt phase diagram (11b) shows overall less coacervate than the Salt, Surfactant, Polymer diagram (11a) and the No Salt diagram. In this experiment, the polymer and surfactant were allowed to mix before salt was added, which promotes ion-exchange interactions. However, once the salt was added, the chemical potential of the system shifts such that ion-exchange is reversed which leads to a resolubilization of the coacervate formed via electrostatic interactions at some compositions. 

Lochhead RY, Warfield DS, Gasiewski C. Phase diagrams as a formulation guide in aqueous polymer/surfactant systems. Polym Eng Sci 1985 25 1110-1117. 

The interaction of cationic polymers with anionic surfactants has been investigated in a number of studies (Banerjee et al. 2013 Dan et al. 2010 Dubief et al. 1989 Goddard and Hannan 1976 Goldraich et al. 1997 Han et al. 2012 Li et al. 2012 Mukherjee et al. 2011 Shubin 1994 Winnik et al. 1997). The phase behavior of polymer-surfactant system under interaction and the influences of factors such as micelle surface charge density, polyelectrolyte molecular weight, and polyelectrolyte-to-surfactant ratio have been explored. The interaction behavior of cationic polymer and anionic surfactant is generally found to be similar to the interaction behavior of anionic polymer and cationic surfactant discussed in the preceding section. 

Piculell, L. Lindman, B. Karlstroem, G. Phase behavior of polymer-surfactant systems. In Kwak, J.C. Ed, Polymer-surfactant system. Surfactant science series 1998, vol 77 pp 65-141... 

Lindman, B., Carlsson, A., Gerdes, S., Karlstroem, G., Piculell, L., Thalberg, K., et al. (1993). Polysaccharide-surfactant systems interactions, phase diagrams and novel gels. In Dickinson, E., Walstra, P. (Eds). Food Colloids and Polymers Structure and Dynamics, Cambridge, UK Royal Society of Chemistry, pp. 113-125. 

Finally, it should be mentioned that a combination of COSMO-RS with tools such as MESODYN [127] or DPD [128] (dissipative particle dynamics) may lead to further progress in the area of the mesoscale modeling of inhomogeneous systems. Such tools are used in academia and industry in order to explore the complexity of the phase behavior of surfactant systems and amphiphilic block-co-polymers. In their coarse-grained 3D description of the long-chain molecules the tools require a thermodynamic kernel... 

This chapter reviews the wide range of colloidal systems amenable to investigation by FT - IR spectroscopy. Molecular level information about die interactions of amphiphilic substances in aggregates such as micelles, bilayers, and gels can be obtained and related to the appearance and stability of the various phases exhibited. The interactions of polymers, surfactants and proteins with interfaces, which substantially modify the solid - liquid or liquid - air interface in many important industrial and natural processes, can also be monitored using FT - IR. 

For a successful incorporation of a pigment into the latex particles, both type and amount of surfactant systems have to be adjusted to yield monomer particles, which have the appropriate size and chemistry to incorporate the pigment by its lateral dimension and surface chemistry. For the preparation of the miniemulsions, two steps have to be controlled (see Fig. 14). First, the already hydrophobic or hydrophobized particulate pigment with a size up to 100 nm has to be dispersed in the monomer phase. Hydrophilic pigments require a hydro-phobic surface to be dispersed into the hydrophobic monomer phase, which is usually promoted by a surfactant system 1 with low HLB value. Then, this common mixture is miniemulsified in the water phase employing a surfactant system 2 with high HLB, which has a higher tendency to stabilize the monomer (polymer)/water interface. 

Emulsion Solvent Evaporation The basic concept of the emulsion solvent evaporation technique producing nanoparticles is very straightforward. The particles are formed as an emulsion of a polymer-surfactant mixture and dispersed in an organic solvent. The solvent is then evaporated to leave behind the individual emulsion droplets which form stable free nanoparticles [203], This method is far easier and more preferable over methods such as spray drying and homogenization and operates under ambient conditions and mild emulsification conditions. The size and composition of the final particles are affected by variables such as phase ratio of the emulsion system, organic solvent composition, emulsion concentration, apparatus used, and properties of the polymer [204],... 

Karlstrom, G. Carlsson, A. Lindman, B., "Phase Diagrams of Nonionic Polymer-Water Systems. Experimental and Theoretical Studies of the Effects of Surfactants and Other Cosolutes," J. Phys. Chem., 94, 5005 (1990). 

In the nonionic system observed under EVM, the initial microemulsion showed no tendency of gelation until it reached 60 C. After reaching 60<>C, the system gels and starts to polymerize after 10-12 hours. As polymerization proceeds, the water separates out. After about 20-24 hours, the gel starts to become a solid with an excess emulsion phase formed at the bottom. The polymerization is essentially complete after 36 hours. Due to different modes of polymerization in the anionic and nonionic surfactant systems, the mechanical properties of the solid are different. The polymers obtsuned from anionic microemulsions are brittle, while those obtmned from nonionic microemulsions are ductile. 

The effect of water soluble polymers on the phase behavior of the anionic mlcroemulslon system was studied as a function of surfactant H/L properties. The cloud point temperatures for the neat mlcroemulslons and those containing 1500 ppm HPAM, partially hydrolyzed polyacrylamide, and 1000 ppm Xanthan gum are given In figure 4. The addition of either xanthan blopolymer or HPAM results In an Increase In the cloud point temperature of the mlcreomulslon. Both polymers have similar Interactions with the mlcroemulslon. Again one observes a lipophilic shift of the mlcroemulslon system Indicative of a repulsive interaction between the polymer and these anionic surfactants. 

The first part of the book discusses formation and characterization of the microemulsions aspect of polymer association structures in water-in-oil, middle-phase, and oil-in-water systems. Polymerization in microemulsions is covered by a review chapter and a chapter on preparation of polymers. The second part of the book discusses the liquid crystalline phase of polymer association structures. Discussed are meso-phase formation of a polypeptide, cellulose, and its derivatives in various solvents, emphasizing theory, novel systems, characterization, and properties. Applications such as fibers and polymer formation are described. The third part of the book treats polymer association structures other than microemulsions and liquid crystals such as polymer-polymer and polymer-surfactant, microemulsion, or rigid sphere interactions. 

Many of the basic concepts of micellar-polymer flooding apply to alkaline flooding. However, alkaline flooding is fundamentally different because a surfactant is created in the reservoir from the reaction of hydroxide with acidic components in crude oil. This reaction means that the amount of petroleum soap will vary locally as the water-to-oil ratio varies. The amount of petroleum soap has a large effect on phase behavior in crude-oil-alkali-surfactant systems. 

The goals of this work have been to determine the effect of polymers on the phase behavior of aqueous surfactant solutions, prior to and after equilibration with oil, to understand the mechanism of the so-called "surfactant-polymer interactions (SPI) in EOR, to develop a simple model which will predict the salient features of the phase behavior in polymer-microeraulsion systems, and to test the concept of using sulfonate-carboxylate mixed microemulsions for increased salt tolerance. 

The effect of polymers on microemulsions phase behavior has been reported by Hesselink and Faber (8). They have described the surfactant-polymer phase separation in terras of the incompatibility of two different polymers in a single solvent, considering the microemulsion as a pseudo-polymer system. The effect of polymers on the phase behavior of micellar fluids has been recently studied by Pope et al. (9) and others (10,11). 

The other observations were reported elsewhere, however. Figure 13.3 shows polymer made the surfactant system emulsification better, and Figure 13.4 shows polymer slightly changed the value of electrophoretic mobility. The addition of polymer into an ASP system does not change IFT but shortens the phase separation time of emulsions. In these examples, when alkali concentration was below 1%, as the concentration was increased, the phase separation time decreased. When alkali concentration was above 1%, the phase separation time increased with the concentration. Thus, polymer apparently reduced the interaction between oil and alkali when alkali concentration was high. 

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