Chitosan, low molecular weight, was supplied by the company
Sigma-Aldrich (Poznan, Poland). The deacetylation degree (DD, %) of
chitosan was 80% and it 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) [23]. The molecular weight of chitosan was determined
by the viscometric method using the well-known Mark–
Houwink equation. The molecular weight of chitosan determined by
this method was 4.38 × 107 g/mol. The intrinsic viscosity of CTS was
measured with an Ubbelohde viscometer in 2% acetic acid/0.2 M sodium
acetate solution.