engleski

Interactions in Biopolymer/Surfactant Mixtures

The interactions of biopolymers and oppositely charged colloidal particles have been recently received great attention due to the importance of resulting aggregates as the complex vesicle-based structures. Interactions between a polyelectrolyte and an oppositely charged surfactant are characterized by the fact that the complexation takes place in a highly cooperative manner. Numerous papers dealing with interactions in these mixtures have revealed that self-organization occurs from nano to macroscopic length scales involving processes of complexation, precipitation and gelation. In this work, we examined in detail the phase behavior, structure and dynamics of complexes formed in the mixture of anionic polysaccharides, carrageenans (CAR) and model cationic surfactant, dodecylammonium chloride (DDACl). Here, we compared three main carrageenan species (κ -, ι - and l-carrageenan) from the point of view of their charge under the concentration conditions from infinite dilution to the phase separation. The results revealed that main factors governing the formation of the soluble and insoluble polyelectrolyte-surfactant complexes (PSC) are electrostatic and hydrophobic interactions. ESR preliminary experiments showed that the local mobility of surfactant in micelle with bound carrageenan chains is lower than in “ free” micelles and depends on the concentration and charge of carrageenans.

biopolymer; surfactant; carrageenan

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