tigh tening unit that comes with the instrument was used toensure the maximum contact between crystal and the sample. FTIRspectra were recorded between 4000 cm−1and 600 cm−1with theresolution of 4 cm−1in the absorbance mode for 128 scans at roomtemperature.X-ray diffraction (XRD) measurements were carried out using(Brucker D8 Focus X-ray Diffractometer) Cu-K radiation emittedfrom X-ray tube operated at 30 kV and 25 mA. Samples were driedfor 2 h at 60◦C for removal of any excess moisture and diffractionpatterns were recorded at room temperature.Thermogravimetric analysis (TGA) was performed for finelygrounded chitin flakes, chitosan flakes, chitin NFs and chitosan NFsand chitosan NPs mixture using Q-600 TGA from TA-Instruments.Approximately 9–10 mg of the sample was placed inside the alu-mina pan and heated from 30◦C to 700◦C at a heating rate of20◦C/min under a N2purge of 100 ml/min.