Thermal, Structural and Morphological Studies of Cellulose and Cellulose Nanofibers Extracted from Bitter Watermelon of the Cucurbitaceae Family

This work presents a new way to prepare and isolate nanometric cellulose fibrils as extracted from Citrullus Colocynthis (Cc) seeds. The nanofibrils were then characterized using spectroscopic, thermal and morphological/structural techniques. IR-Raman spectra of cellulose fibers confirmed that the treatment they went through, effectively removed all non-cellulosic material (i.e. hemicellulose and lignin). In addition to that, TGA results indicated a good and higher thermal stability of the extracted cellulose. HPLC and ¹H NMR measurements were carried out to estimate the chemical composition of cellulose from Cc seeds. TEM confirmed the presence of nanofibers in the treated sample; XRD (WAXS-SAXS) data show that the cellulose nanofibers have a higher crystallinity. The preparation (extraction and treatment) of cellulose and cellulose nanofibers from the Cc seeds as well as their thermal, structural and morphological characterizations, were successful.