Cellulose Nanofibers as Functional Biomaterial from Pineapple Stubbles via TEMPO Oxidation and Mechanical Process

Abstract

The pineapple fruit when harvested generates a large amount of residual biomass; this biomass can be used to generate value-added products such as cellulose nanofibers. This study was focused on the isolation of CNF from pineapple leaves after oxidation pretreatment with 2,2,6,6-tetramethylpireridine-1-oxyl, followed by mechanical deconstruction of the fibers via combination of grinding and microfluidization process. One and two microfluidization passes were applied to bleached and unbleached fibers, respectively. The implications of these findings are that during the production process it is possible to reduce the amount of chemicals needed for bleaching and the energy involved in the mechanical microfluidization process. Such process yielded corresponding fibril lengths and widths in the range of 481–746 nm and 16–48 nm. The respective electrostatic charges, as measured by zeta potentials, were −41 mV and −31 mV. As expected, the CNF crystallinity was higher than that of the starting material, especially for the cellulose. However, the thermal stability was reduced, showing two degradative processes due to the chemical modification of the fibers. The CNF produced from pineapple leaves has a potential to be used like biomaterial in diverse applications while representing a viable alternative to producers, which face serious environmental and health challenges given the large volume of biomass that is otherwise left in the fields as waste. Graphic Abstract

Extraction of microfibrillated cellulose from elephant egesta and evaluating its reinforcing ability in pectin/alginate packaging films

“…It is due to the removal of water or moisture loosely bound to the sample's surface. The removal of water from the cellulose surface takes place within 50–180°C, as reported in the literature studies 55,56 . As we move on to the second degradation stage, a maximum loss is observed (76.4%) at a temperature range from 140 to 376°C.…”

“…The removal of water from the cellulose surface takes place within 50-180 C, as reported in the literature studies. 55,56 As we move on to the second degradation stage, a maximum loss is observed (76.4%) at a temperature range from 140 to 376 C. The crystalline nature of MFC is exhibited from the high onset temperature peak at 332 C (Table 3), which corresponds to the glycosidic bond cleavage in cellulose leading to the formation of CO 2 , H 2 O, and various hydrocarbon derivatives. This degradation is due to the reorientation of crystals in cellulose.…”

Influence of reaction variables on the surface chemistry of cellulose nanofibers derived from palm oil empty fruit bunches

“… 68 Similarly, TOCNs extracted from bleached and unbleached pineapple stubbles had diameters of 15.5 and 47.9 nm, respectively, as determined by atomic force microscopy; a microfluidizer was used after TEMPO. 69 Additionally, mild shearing was used as a pretreatment for bleached and unbleached paulownia wood to obtain TOCNs with diameters of 5.0 and 6.0 nm, respectively, as observed by FESEM. 23 It is evident that TOCNs extracted from different biomass and subjected to various pre- and post-treatments exhibit distinct sizes.…”

Preparation of nanocellulose by a biological method from hemp stalk in contrast to the chemical method and its application on the electrospun composite film

“…Biological solution preparation: 58 the following samples were prepared; 1.5% pectin lyase, 0.4% sodium hydroxide, 0.13% sodium carbonate, 0.17% sodium chloride, 0.13% calcium chloride, 0.03% sodium phosphate, 0.02% sodium formate, 0.2% sodium silicate, 0.13% sodium sulfite, 0.15% ethylene glycol, as well as distilled water of 97.0%. The solution was prepared in proportion; weak acid solution preparation: 59 5% sodium chlorite, 0.8% acetic acid, and 94.2% water in proportion; chemical solution preparation: 60 dilute 98% concentrated sulfuric acid to 54% H 2 SO 4 and cooled to ambient temperature.…”

“…14,15 The TEMPO method can form a carboxylic acid group, which selectively oxidizes the hydroxyl group at the C6 on the cellulose, and can be dispersed in the aqueous solution to form colloidal with low concentrations (usually 0.2% by mass). 16 However, the preparation by enzyme hydrolysis, commonly using OS1 fungi, endoglucanase, cellulose in cotton, sugarcane bagasse, and pulp with lower lignin content, 17,18 is rarely reported. Edi et al successfully isolated nanocellulose fibers with a diameter of 19 nm, length of 1 mm, crystallinity of 73.65%, and preparation rate of 89.39% using chemical auxiliaries and ultrasound.…”