Adsorption and viscoelastic properties of chitosan lactate at the liquid-gas interface

Abstract

The surface tension and dilational rheological properties (viscoelasticity modulus and phase angle) of chitosan lactate solutions at the liquid-gas interface are investigated by the oscillating drop shape method. The results were analyzed using the adsorption model proposed earlier for proteins in the framework of non-ideal two-dimensional solution theory. It was found that the experimental values of equilibrium surface tension of chitosan lactate solutions are in good agreement with this model. The results of the dynamic surface tension and adsorption kinetics analysis showed that chitosan lactate is characterized by a non-diffusion (barrier) adsorption mechanism. This fact determines the qualitative predictive value of the applied theoretical model to describe the extreme behavior of the dependence of the viscoelasticity modulus on the surface pressure.

Keywords

• Chitosan
• Surface tension
• Viscoelasticity modulus
• Phase angle
• Adsorption model
• Liquid-gas interface