Polymers polymer-surfactant interactions

Originating from Cornwall, Peter Griffiths studied initially at University College, North Wales (1985-88), and subsequently the University of Bristol (PhD, 1991). After post-doctoral positions in Bristol and Stockholm, he moved to a lectureship at Cardiff in 1995. Aged 32, his research interests centre around colloidal systems, in particular polymer/surfactant interactions. 

T. R. French and C. B. Josephson. The effect of polymer-surfactant interaction on the rheological properties of surfactant-enhanced alkaline flooding formulations Topical report. US DOE Fossil Energy Rep NIPER-635, NIPER, February 1993. 

Fluorescence spectroscopy is also particularly well-suited to clarify many aspects of polymer/surfactant interactions on a molecular scale. The technique provides information on the mean aggregation numbers of the complexes formed and measures of the polarity and internal fluidity of these structures. Such interactions may be monitored by fluorescence not only with extrinsic probes or labelled polymers, but also by using fluorescent surfactants. Schild and Tirrell [154] have reported the use of sodium 2-(V-dodecylamino) naphthalene-6-sulfonate (SDN6S) to study the interactions between ionic surfactants and poly(V-isopropylacrylamide). 

Polymer/Surfactant Interactions. Interaction between polymers and surfactants was recently reviewed by Robb (11) and surfactant association with proteins by Steinhardt and Reynolds (12). Polymer/surfactant interactions are highly dependent on the chemical nature of the polymer and the surfactant. In general, surfactants tend to associate with uncharged polymers in aggregates rather than individual surfactant molecules interacting with the macro-molecule. The ability of surfactants to form micelles is thought to be an important factor in the role of surfactant behavior in interactions with polymers. Individual surfactant... 

P. Somasundaran, B. Markovic, S. Krishnakumar, and X. Yu, Colloid Systems and Interfaces - Stability of Dispersions Through Polymer and Surfactant Interaction , Ch. 14 in Handbook of Surface and Colloid Chemistry , K.S. Birdi (ed.), CRC Press, Boca Raton, Florida (1997). 

In recent years the investigation of polymer-surfactant interactions is a rapidly growing field of interest of modem colloid science [1-4], The mixtures and multilayer structures of polyelectrolytes and surfactants are widely used for industrial application to govern the wetting, adhesion, flotation processes and so on. 

Nizri G, Lagerge S, Kamyshny A, Major DT, Magdassi S. (2008) Polymer-surfactant interactions Binding mechanism of sodium dodecyl sulfate to poly(diallyldimethylammonium chloride). / Colloid Interface Sci 320 74-81. 

The discussion so far has been limited to polymer-surfactant Interactions in the bulk solution. In the section to follow, interactions at the air-liquid Interface are examined. 

Bloor, D.M. HoUwarth, J.F. Wyn-Jones, E. Polymer/ surfactant interactions the use of isothermal titration calorimetry and EMF measurements in the sodium dodecyl sulphate/poly(A-vinylpyrrolidone) system. Langmuir 1995, 11, 2312-2313. 

Polymer surfactant interaction has been examined by using sodium 2-(N-dodecyIamino)naphthalene-6-sulphonate as a probe. Solute-solvent interaction of free base phthalocyanine has been examined in both polyethylene and polystyrene by the effect of pressure on spectroscopic hole burning s Fluorescence has been used to indicate the onset of aggregation in water soluble polymers s interaction of pyrenylmethyltributylphosphonium bromide with single strand polynucleotides , and the interaction of indole compounds with synthetic polyelectrolytes. ... 

Goddard ED. Polymer—surfactant interactions. Part I. Uncharged water-soluble polymers and charged surfactants. In Goddard ED, Ananthapadmanabhan KP, eds. Interactions of Surfactants with Polymers and Proteins. Boca Raton, FL CRC Press, 1993 123-169. 

Polymer-surfactant interactions are the basis for the rheological behavior of MHAPs. Other surfactant-polymer systems have previously been investigated. One example is the interaction of surfactants with polymers such as poly(ethylene oxide), which results in greater solution viscosities than with the polymer alone (e.g., ref. 25 and references therein). The interaction of surfactants or latexes with hydrophobically modified water-soluble polymers has also been shown to produce unique rheology (2, 5, 26, 27). In these systems, the latex particles or the surfactant micelles serve as reversible cross-link points with a hydrophobic region of a polymer molecule in dynamic association with a latex particle or surfactant micelle (27). 

Figure 3, Reproducibility of high-throughput screening methods for cellulosic polymer-surfactant interaction contour phase diagrams,...

ATTRACTIVE POLYMER-SURFACTANT INTERACTIONS DEPEND ON BOTH POLYMER AND SURFACTANT... 

From this discussion, it is thus clear that a number of factors influence polymer-surfactant interactions. However, we can define three categories of surfactant binding to polymers, as follows ... 

Hydrophobic interactions are important in all three cases but there are important differences. In case 1, the normal surfactant-surfactant hydrophobic interaction is very similar to what applies in the absence of polymer while the attractive polymer-surfactant interaction is due to electrostatics. In case 2, there is a weak hydrophobic polymer-surfactant attraction (and an even weaker polymer-polymer attraction) and a partial elimination of an unfavourable surfactant-surfactant electrostatic repulsion. In case 3, there are strong... 

Experimental methods for investigating polymer-surfactant interactions vary widely, but they generally fall into two categories those that measure the macroscopic properties of a system (viscosity, conductivity, dye solubilization, etc.) and those that detect changes in the molecular environment of the inter-... 

FIGURE 14.5. In some polymer-surfactant interactions there is evidence for the formation of micelle-like or hemimicelle aggregates of surfactant molecules along the polymer chain—something like a string of pearls. ... 

FIGURE 14.7. If an aqueous polymer-surfactant interaction occurs via the surfactant tail, the resulting complex will generally exhibit modified solution characteristics, usually reflecting a greater interaction with water and an expanded chain conformation. 

FIGURE 14.8. If a polymer-surfactant interaction occurs via the head group, the polymer will often exhibit solution characteristics reflecting a smaller, more compact configuration, even to the point of precipitation. 

FIGURE 14.12. Polymer-surfactant interactions are important in many areas of polymer science and technology, especially emnlsion polymerization. In snch processes surfactants and micelles perform several dnties snch as emulsification of monomers (a), solnbihzation of growing oUgomeric free radical chains (b), and stabilization of growing and final polymer particles (c). 

The striking difference of behavior between SDS and TTAB as far as changes of CMC and 3 are concerned suggest that the polymer-surfactant interaction occurs at the level of the surfactant ionic head group and does not involve the surfactant alkyl chain. This is turn means that the penetration of the polymer in the micelle will be restricted to the head group region, with little if any at all, penetration of the polymer in the micelle hydrophobic interior. Thus, the polymer surfactant interaction can be looked at as an adsorption of the polymer chain on the micelle surface. ... 

A fundamental question as to the nature of polymer-surfactant interaction arises from the large difference between the mass of polymer and that of surfactant molecules. The adsorption concept emphasizes that the polymer is a large unit and it has many sites available for surfactant binding. In the complex formation model, the stress is on the elementary process between one polymer site and the surfactant molecule, disregarding the fact that the polymer sites are linked with each other in the polymer chain. 

In order to describe the polymer-surfactant interaction, the important points to be dealt with are as follows ... 

The description of the polymer-surfactant interaction outlined above is based on the conception that the complex formation is a cooperative process of surfactant ions and reflects the general experimental finding, viz., the existence of a critical surfactant concentration for interaction. It also suggests a decrease of Cgp with increasing polymer concentration, which was experimentally found by many authors, as well as the appearance of two breakpoints in the different colligative properties vs. surfactant concentration curves. 

Viscosity is one of the most frequently applied method to study the polymer surfactant interaction. The hydrodynamic data are expressed in various ways viscosities relative to the solvent (water) or to the surfactant solution furthermore, specific viscosity measured as a function of polymer concentration at constant surfactant concentration and as a function of surfactant concentration at constant polymer content as well as measurements at a constant polymer/surfactant concentration ratio can be found in the literature. In some cases, efforts were made in order to determine the intrinsic viscosity of the polymer-surfactant complex by extrapolation from the linear region of the Tigp/cp vs. Cp function in spite of the fact that at low polymer concentration it shows anomaly. ... 

---