Preparation of the Polymer Solution Solutions of 8, 10, and 12% (w/v) chitosan were prepared in TFA:DCM at two different weight ratios (80:20 or 90:10). The solutions were prepared under constant mechanical stirring (Selecta Multimatic 5S) in a heating-bath at 70°C until completely dissolution occurred, and then at room temperature for a further 48 h.