CHITOSAN/ALGINATE POLYELECTROLYTE MULTILAYERS: EFFECT OF pH AND IONIC STRENGTH ON FILM GROWTH AND MORPHOLOGY

Abstract

The growth process of chitosan/alginate polyelectrolyte films deposited by layer-by-layer assembly at different pH and ionic strength was studied in this work. The films were investigated using surface plasmon resonance (SPR) to examine the build-up kinetics, and atomic force microscopy (AFM) to visualize the surface topography. Each deposition step resulted in a progressive increase in mass. The film growth and thickness strongly depended on the polyelectrolyte charge density and complexation between the used polyelectrolytes. The film surface changed from smooth to rough when the pH increased. The results achieved could be used in estimating the potential of the multilayers to be applied as drug delivery systems.