Chitosan, low molecular weight was supplied by the company
Sigma-Aldrich (Poznan, Poland). The deacetylation degree (DD, %)
of chitosan was determined by the conductometric titration method,
taking the first derivative of the conductivity of the chitosan solution
(dissolved in 0.1 M HCl) and the volume of the titration solution
(0.1 M NaOH), and using the following equation: