*2.5. Morphological Evaluation*

The morphology of all samples was investigated by field emission scanning electron microscopy (FESEM) using a FEG-Quanta 450 instrument (FEI, Hillsboro, OR, USA). From all the samples constituted by the chitin and polyphenols sprayed on aluminium foils and the coated and uncoated paper tissues, a 1 × 1 cm square was cut with a hand precision scissor. Cut samples were stuck on an aluminium stub with a diameter of 12 mm through conductive carbon scotch. Stabs were sputtered with Pt using a LEICA EM ACE600 highvacuum sputter coater (LEICA, Buccinasco, Italy) to make them conductive.
