Extended surfactants

Extended surfactants behave essentially as conventional surfactants with similar head groups as far as the formulation variable effects are concerned. The polypropylene group behaves as a part of the lipophilic tail, but its presence alters the value of the k coefficient in the HLD expressions [52]. Extended surfactants maybe mixed with conventional surfactants to attain intermediate formulations which are often closely described by a linear mixing rule. Hence, the formulation of systems containing an extended surfactant may be finely tuned by adding conventional ones. 

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Figure 3.9 Solubilisation improvement of a conventional surfactant (a) by a lipophilic linker (b), an amphiphilic linker (c), or an extended surfactant (d).

Minana-Perez, M., Graciaa, A., Lachaise, J. and Salager, J.L. (1995) Solubilization of polar oils with extended surfactants. Colloids Surf A, 100, 217-224. 

Fernandez, A., Scorzza, C., Usubillaga, A. and Salager, J.L. (2005) Synthesis of new extended surfactants derived from a xylitol polar group. /. Surfactants Detergents, 8, 193-198. 

Witthayapanyanon, A., Acosta, E.J., Harwell, J.H. and Sabatini, D.A. (2006) Formulation of ultralow interfacial tension systems using extended surfactants. /. Surf. Deterg., 9(4), 331-339. 

Bicontinuous microemulsions have been formulated to solubilize polar oils, even of the triglyceride type, because of a new generation of the so-called extended surfactants, which contain a poly(xl0)propylene oxide intermediate polarity chain in between the (ionic) hydrophilic and lipophilic groups [51,52,126]. 

Since the solubilization of oil phases other than alkanes in nonbicon-tinuous microemulsions is not very high (say, below 0.5 g of oil per gram of surfactant) unless fancy new molecules are used such as the so-called extended surfactants that are able to solubilize triglycerides [51,52], it is probable that many apparently solubilized systems referred to as O/W microemulsion are really miniemulsions produced by phase inversion [132]. 

The slow motion correlation time was interpreted in terms of Eqs. (12)-(14), which contain two unknown parameters, R and Aat- However, D at can be measured in phases of extended surfactant films, such as bicontinuous cubic phases, and R is expected to be close to the overall length of the surfactant molecule. Using Diat l x 10 " m /s as measured in a bicontinuous cubic phase of the similar surfactant hexadecyltrimethylammonium fluoride and the radius R = 2.4 nm, a slow motion correlation time of approximately 10 ns is calculated from Eqs. (12)-(14), which is in reasonable agreement with the experimentally determined value. 

Uses Solvent in hydraulic brake fluids, cutting oils, textile lubricants, printing inks aromatics extraction solvent comonomer in unsat. polyester and alkyd resins reinforced plastics plasticizers in paints cosmetics in food-pkg. adhesives fragrance fixative/diluent petroleum anti-icing additive PU chain extender surfactant for unsat. polyester resins, paints in paper/paperboard in contact with aqTfatty foods defoamer in food-contact coatings in surf, lubricants for mfg. of food-contact metallic articles... 

We should note that the fact that the micelle radius equals the length of an extended surfactant... 

Angelika Klaus, Gordon Tiddy, Didier Touraud, Anette Schramm, Georgine Stiihler, and Werner Kunz, Phase behavior of an extended surfactant in water and a detailed characterization of the concentrated phases, Langmuir 26 (22) (2010) 16871-16883. 

An example of such a so-called extended surfactant is the alkyl polypropyleneoxy ethoxy sulfate sodium salt with several propylene oxide groups, for instance... 

Figure 25 Solubilization of different oils at optimum formulation with extended surfactants. [Reprinted from Ref. 156 with kind permission from Elsevier Science-NL, Sara Burgerhartstraat 25, 1055 KV Amsterdam, The Netherlands.]...

Do L, Sabatini D. 2010. Aqueous Extended-Surfactant Based Method for Vegetable Oil Extraction Proof of Concept. J. Am. Oil Chem. Soc. 87(10) 1211-1220. 

Uses For plasticizers, extenders, surfactants in grinding and cutting oils, specialty lubricant additives, corrosion inhibitors, specialty soivs. for printing inks, metalworking, and oil well servicing... 

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