Study of the complex formation between sodium dodecyl sulfate and chitosan

This paper reports some experimental results about the binding of Sodium Dodecyl Sulfate to cationic chitosan (Mw = 190,000 g/mol, acetylation degree = 0.16) in aqueous solution. Polymer–surfactant complexes have been investigated at room temperature (298 K). Binding isotherms of SDS with chitosan have been correlated with surface tension measurements. Turbidity and zeta potential measurements have also been studied, so as to obtain information on the structure of the complexes in the bulk phase. Finally, isothermal titration calorimetry (ITC) allowed some conclusions to be drawn concerning the extent of the hydrophobic interactions.This study provides information about optimal ionic ratio and our system appears to be eligible as wall material for capsules using the coacervation process. That type of capsules may be useful for the design of chitosan-based food ingredients with specific functional characteristics.