were then heated
up to 95 C under stirring, and afterwards 60 ml of silver
nitrate solution (7, 12, 26, 52 mM) was added dropwise under
heating. The dispersions were kept under stirring for 12 h.
A darkening was clearly observable, indicating the formation
of silver nanoparticles. The lower the molecular weight of
the chitosan, the darker the resulting color of the colloidal
silver–chitosan nanocomposites.