Inulin polymeric surfactant

Exerowa, D., Gotchev, G., Kolarev, T. et al. (2007) Interaction forces in thin liqnid films stabilized by hydrophobically modified inulin polymeric surfactant. 2. Emulsion films. Langmuir, 23 (4), 1711-1715. 

Wetting Films Stabilized by Hydrophobically Modified Inulin Polymeric Surfactant... 

Tadros, T.F., Vandamme, A., Levecke, B., Booten, K., and Stevens, C.V., Stabilization of emulsions using polymeric surfactants based on inulin, Adv. Colloid Interface Sci., 108, 207-226, 2004. 

MgS04, stability could be maintained at high temperatures up to 1 mol/dml Thus, these cloud point measurements give conclusive evidence of the unique behavior of polymeric surfactants based on inulin. The poly fructose chain remains hydrated up to high temperatures and in the presence of high electrolyte concentrations. Thus, by adequate design of the polymeric surfactant, one can achieve very high stability for the emulsions. 

Recently ORAFTI (Belgium) developed a polymeric surfactant based on inulin (a natural, linear polyfructose molecule produced from chicory roots) [24]. By grafting several alkyl chains on the polyfructose chain a graft copolymer was produced (Fig. 1.22). 

To achieve the above effect it is useful to use A-B-A block copolymers that are soluble in the oil phase euid insoluble in the continuous phase. A strongly adsorbed polymeric surfactant that has limited solubility in the aqueous phase can also be used (e.g. hydrophobically modified inulin, 1NUTEC SP1 - ORAFTl, Belgium) as will be discussed below. 

Stevens, C. V., Meriggi, A., Peristerpoulou, M. et al. (2001) Polymeric surfactants based on inulin, a polysaccharide extracted from chicory. 1. Synthesis and interfacial properties. Biomacromolecules, 2 (4), 1256-1259. 

Finally, the area is enlarged a bit by looking at larger surface-active molecules that one could describe as surface-active polymers or polymeric surfactants. Here mature types of products like cellulose derivatives and lignosulfonates, as well as the newer inulin products, are treated. 

Hypeimer CF-6, and Inulin. In general, the abilities of polymeric surfactants to decrease surface and interfacial tension are mnch lower than those of the low-molecular-weight surfactants. Block copolymers exhibit low CMC and lower diffnsion coefficient with respect to classical surfactant. Triblock copolymers are mnch more efficient than the diblock copolymers with the same composition and molecnlar weight [24]. 

Thin liquid films have proven their advantages in the study of interaction forces in foam, emulsion, and wetting films stabilized by various types of surfactants see, for example. Refs. l-3]. DLVO and non-DLVO surface forces that stabilize these films have been established in many cases the relation between surface forces and film stability has also been found. Recently, several authors have reported results of model experiments with thin liquid films (foam, emulsion and wetting films) stabilized by polymeric surfactants. In our laboratories all three types of films from aqueous solutions of A-B-A triblock copolymers [4—6] or AB hydrophobically modified inulin [8-10] have been studied. The corresponding disperse systems (foams, emulsions, suspensions) stabilized by AB polymeric surfactants have also been studied extensively see, for example. Refs. [11-14]. It was supposed that the stabilizing forces are steric surface forces but they have not been directly proven and quantitatively studied. 

Here we review the results obtained [4—10] with two types of non-ionic polymeric surfactants (i) A-B-A triblock copolymers and (ii) novel graft polymeric surfactants based on inulin. 

In summary, it has been established, using microscopic foam films, that films from aqueous solutions of polymeric surfactants (A-B-A block copolymers and AB graft polymers based on inulin) are stabilized by both electrostatic, DLVO and steric, non-DLVO surface forces. Application of the scaling theory of de Gennes [39, 40] to describe the brush-to-brush and loop-to-loop interactions is interesting. 

For INUTEC SPl, the graft polymeric surfactant based on hydrophobically modified inulin, the critical dectrolyte concentration, Cdo, that separates DLVO from non-DLVO interactions is 5 x 10 moldm [8j. The effect of the electrolyte on the electrostatic component of disjoining pressure is dearly seen, and the film thickness remains constant h =ll nm) above where steric interactions are acting. 

Although the above sugar surfactants found many applications, particularly in cosmetics and personal care products, they are seldom very effective in stabilization of disperse systems against flocculation and/or coalescence. This is due to the reversible nature of adsorption of these molecules at the solid/liquid or liquid/liquid interfaces. For that reason we have developed a polymeric surface-active molecule based on inulin (which is extracted from chicory roots). Inulin is a polydisperse polysaccharide consisting mainly, if not exclusively, of j8(2 1) fructosyl fructose units with normally, but not necessar-... 

Nestor, J., Esquena, J., Solans, C. et al. (2005) Emnlsion polymerization of styrene and methyl methacrylate using a hydrophobically modified inulin and comparison with other surfactants. Langmuir, 21 (11), 4837-4841. 

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