Composite effect of silica nanoparticle on the mechanical properties of cellulose‐based hydrogels derived from cottonseed hulls

ABSTRACT Recently, cellulose‐based hydrogel nanocomposite materials have been attracted increasing attention owing to their potential applications in different areas including medical, electrical, optical, and magnetic fields. This is due to the fact that cellulose is one of the most abundant resources and possesses several unique properties required in medical fields, whereas silica nanoparticles (nSiO2) play an important role in developing materials with high functionality. In this study, cottonseed hull (CSH) was used as a source of cellulose and nSiO2 was used to prepare hydrogel nanocomposite films via phase inversion method without chemical crosslinking agent of cellulose. CSH was first pre‐treated with sodium hydroxide (NaOH) and sodium hypochlorite (NaOCl) for delignification and bleaching, respectively. The pre‐treated CSH exhibited whiter fiber and lower amount of lignin as compared with the untreated CSH. The properties of cellulose‐base hydrogel were found to be improved as a result of the addition of nSiO2 at 2–6 wt % for tensile strength and up to 10 wt % for modulus and elastic modulus (G′). However, the elongation at break was decreased with the incorporation of nSiO2. Moreover, the TEM images displayed the nano‐grape structure of nSiO2 surrounded by cellulose molecules. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44557.