Isolation and characterization of cellulose nanocrystals from Cucumis sativus peels

The valorization of municipal grass waste for the extraction of cellulose nanocrystals

“…Therefore, it is worth mentioning that valorization of such green waste material is a favorable approach for the extraction of CNCs without impeding with the commercially or widely used cellulosic-based material sources. Various other sources of agro-waste materials for the production of CNFs or CNCs have also been reported such as sugarcane bagasse, 38 rice straw, 39 oil palm empty fruit bunch, 40 apple pomace, 41 cucumber peels, 42 tomato peels, 43 pineapple peels, 44 and royal palm tree. 45 In addition, the accessibility for the isolation of cellulose bers from grass waste is an alternative initiative to other commonly used precursors.…”

A Review of Lignocellulosic-Derived Nanoparticles for Drug Delivery Applications: Lignin Nanoparticles, Xylan Nanoparticles, and Cellulose Nanocrystals

“…>85%), where the dimension range of CNCs are 100-3000 nm in length, 3-50 nm in width, and 5-200 in aspect ratio [41]. CNCs can be used for a wide range of applications due to their advanced properties, such as good biodegradability, good biocompatibility, non-toxic, excellent surface charge, and excellent mechanical property [17,42,43]. CNCs have been used in drug delivery systems, beauty and pharmaceutical products, biomedical engineering, shape-memory materials, optical devices, plastics, coatings, gas and energy storages, additives, bio-fillers, catalysts, and food packaging [17,[42][43][44].…”

“…CNCs can be used for a wide range of applications due to their advanced properties, such as good biodegradability, good biocompatibility, non-toxic, excellent surface charge, and excellent mechanical property [17,42,43]. CNCs have been used in drug delivery systems, beauty and pharmaceutical products, biomedical engineering, shape-memory materials, optical devices, plastics, coatings, gas and energy storages, additives, bio-fillers, catalysts, and food packaging [17,[42][43][44]. Due to their pure cellulose content required in the CNCs, raw material selection is very important to be considered for obtaining high-yield CNCs with advanced properties.…”

“…Several acid solutions have been investigated as the hydrolysis agent for obtaining high purely crystalline cellulose, such as sulfuric acid [47,54], hydrochloric acid [64], oxalic acid [57], and even combined acid solutions [46]. The penetration of hydronium ion (H 3 O + ) from the acid solution used into raw cellulose fiber breaks the β-1,4-glycosidic linkages of the amorphous regions of cellulose so that the amorphous cellulose is degraded into its monomers and remained the crystalline region of cellulose [43,48]. The breaks of β-1,4-glycosidic linkages are also occurred in the crystalline region due to the slight diffusion of acid solution into it.…”

“…As a further matter besides, the residual acid on CNCs are difficult to be separated and purified. Even though the negatively charged sulphate groups on the CNCs surface increase the colloidal stability, especially when the ζ-potential is lower than −30 mV [43], but it can cause potential disruption in certain applications, such as drug delivery system. In recent research, modified or assisted acid hydrolysis methods were developed to enhance the isolation process of CNCs.…”