Interfacial properties of ionic amphophilic systems based on polysaccharides [Propriétés interfaciales de systèmes amphiphiles ioniques àbase de polysaccharides]
cited By 1International audienceAmphiphilic ionic polysaccharides based systems, and more particularly chitin derivatives based ones, can see their amphiphily modified through covalent grafting of hydrophobic chains or the formation of a complex with an oppositely charged surfactant (called SPEC). This work presents the study of the kinetics of the adsorption and of the formation of a structured layer of amphiphilic derivatives of chitosan and SPECs, by dynamic tensiometry and two-dimensional dilatational rheology. Adsorption steps with different characteristic times are demonstrated. The macromolecules take up an extended conformation at the interface. The interfacial activity and kinetics of adsorption do not depend for a monotonous manner upon the degree of substitution and the length of the grafted alkyl chain but the conformation of macromolecules was also an important parameter. The adsorption layer has a "solid-like" behaviour related with the structuring of this layer. As in static tensiometry surfactant-polyelectrolyte complex appears as more efficient the polysoaps considering the adsorption kinetics
