Preparation and characterization of cellulose nanocrystals from spent edible fungus substrate

BACKGROUND Spent edible fungus substrates were identified as potential sources to produce cellulose derivatives, namely purified cellulose and dicarboxyl cellulose nanocrystal (DCNC). Purified celluloses were obtained via chemical treatments and then oxidized by sequential periodate-chlorite without mechanical process. The structural properties of the DCNCs were characterized by transmission electron microscopy (TEM), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and thermal gravimetric analysis (TGA). RESULTS XRD results showed that the cellulose I structure was maintained, however, the crystallinity index decreased after oxidation process. The initial pyrolysis temperature of DCNCs ranged from 242 to 344 degrees C. TEM results revealed that DCNC was rod-shaped with an average length and width of 130.88 nm and 7.3 nm, respectively. The average specific surface area (SSA) was 366.67 m(2) g(-1). The carboxyl content was around 3.485 mmol g(-1). Finally, the adsorption capacity for contaminations was 76.98, 126.22, 64.44 and 9.63 mg g(-1) for copper ion (Cu2+), lead ion (Pb2+), chromium (Cr3+) and amoxicillin (AMX), respectively. CONCLUSION This work showed a sequentially chemical oxidation for preparing nanocellulose from secondary agricultural waste with many functional applications. (c) 2021 Society of Chemical Industry.