title: Interactions and hybrid complex formation of anionic algal polysaccharides with a cationic glycine betaine-derived surfactant.
abstract: The interaction between anionic algal polysaccharides ((κ)-, (ι)-, (λ)-carrageenans, alginate and ulvan) and a cationic glycine betaine (GB) amide surfactant possessing a C18:1 alkyl chain has been studied using isothermal titration calorimetry (ITC), zeta-potential measurements, dynamic light scattering (DLS), transmission electron microscopy (TEM), atomic force microscopy (AFM), and surface tension measurements. It was observed that this cationic surfactant derived from renewable raw materials induced cooperative binding with the anionic polymers at critical aggregation concentration (CAC) and the CAC values are significantly lower than the corresponding critical micelle concentration (CMC) for the surfactant. The CMC of cationic GB surfactant was obtained at higher surfactant concentration in polysaccharide solution than in pure water. More interestingly, the presence of original polysaccharide/surfactant hybrid complexes formed above the CMC value was evidenced from (κ)-carrageenan by microscopy (TEM and AFM). Preliminary investigations of the structure of these complexes revealed the existence of surfactant nanoparticles surrounded with polysaccharide matrix, probably resulting from electrostatic attraction. In addition, ITC measurements clearly showed that the interactions of the κ-carrageenan was stronger than for other polysaccharides ((ι)-, (λ)-carrageenans, alginate and ulvan). These results may have important impact on the use of the GB amide surfactant in formulations based on algal polysaccharides for several applications such as in food, cosmetics, and detergency fields.
authors: Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7, France; Université Européenne de Bretagne (UEB), France.
authors: Rudy
authors: R
authors: Covis
authors: Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7, France; Université Européenne de Bretagne (UEB), France.
authors: Thomas
authors: T
authors: Vives
authors: U.R.1268 Biopolymères Interactions Assemblages INRA-BP 71, 627 Rue de la Géraudière, 44316 Nantes Cedex 3, France; Université Européenne de Bretagne (UEB), France.
authors: Cédric
authors: C
authors: Gaillard
authors: Centre d'étude et de Valorisation des Algues, Presqu'île de Pen Lan-BP3, 22610 Pleubian, France.
authors: Maud
authors: M
authors: Benoit
authors: Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7, France; Université Européenne de Bretagne (UEB), France. Electronic address: thierry.benvegnu@ensc-rennes.fr.
authors: Thierry
authors: T
authors: Benvegnu
mesh_terms: D001622:Betaine / Q000737:chemistry*; D002351:Carrageenan / Q000737:chemistry*; D000461:Rhodophyta / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D013501:Surface-Active Agents; D001622:Betaine; D002351:Carrageenan
keywords: Algal polysaccharides; Cationic surfactant; Food, cosmetics and detergency applications; Physicochemical characterizations; Polymer–surfactant interactions; Polysaccharide/surfactant hybrid structures