Determination of the substitution degree of modified chitosan by cyclic voltammetry at the water/dichloroethane interface

The electrochemical behavior of the cationic polymer chitosan-gtmac (Ch-GTMAC), at the polarized water/1,2-dichloroethane interface was studied. This polymer was obtained by nucleophilic reaction of chitosan (Ch) with glycidyltrimethylammonium chloride groups (GTMAC). The voltammetric response was found to be dependent on the concentration of the polymer, on pH of the aqueous phase, and on the nature of the organic electrolyte. The results suggest a weak adsorption of the polymer coupled to the transfer towards the organic phase. Desorption process is quasi-reversible, and there is not interaction between adsorbents. From the analysis of desorption charge, it was possible to determine the substitution degree of the polymer