Isolation and characterization of cellulose nanocrystals from Cucumis sativus peels

Cucumber (Cucumis sativus) peels waste being a potential cellulosic sources, were used for extracting cellulose nanocrystals (CNCs), and characterized in the present study. Firstly, the cucumber peels were purified chemically through acid, alkali, and bleaching treatments for cellulose isolation. Later obtained cellulose was acid (60 wt% H2SO₄) hydrolyzed at 45 ℃ for 45 min to obtain CNC45 suspension, and again 10 min sonicated for CNC45-S10 suspension. The effect of sonication on the particle size of CNC45, and CNC45-S10 were investigated with Dynamic light Scattering and Atomic force microscopy. The microstructural changes, thermal, and crystalline properties of resulting fibers and CNC45 were analysed after each treatments through scanning electron microscopy, thermo-gravimetric analyser, and X-ray diffraction respectively. The acid-hydrolysed CNC45 from cucumber peels showed rod-like shape with high crystallinity (74.1 %), excellent thermal stability (>200 °C), and negative zeta potential values (<−30 mV), and CNC45 can be used as potential nanofillers.