Enzymatic-mediated production of cellulose nanocrystals from recycled pulp

Recent Strategies in Preparation of Cellulose Nanocrystals and Cellulose Nanofibrils Derived from Raw Cellulose Materials

“…EG is used to hydrolyze cellulose amorphous regions, and much more crystalline regions are retained in the process. Filson and coworkers successfully prepared CNCs using endoglucanase to hydrolyze recycled pulp [103]. They found that when the endoglucanase was increased to 420 EGU per 1 g pulp and the reaction temperature was at 50 ∘ C with microwave heating for 60 min, the CNCs with the diameter of 30-80 nm and the length of 100 nm-1.8 m could be obtained, the yield was up to 38.2%, the average zeta potential was −31.37 mV, and birefringence could be observed for the CNCs dispersion.…”

Enzymatically-Mediated Co-Production of Cellulose Nanocrystals and Fermentable Sugars

“…Zhu et al reported that the crystallinity of cellulase cocktail-treated Kraft pulp improved with longer enzymatic treatment and CNC-like particles were generated by homogenization [42]. There were also efforts to produce CNCs solely by endoglucanase treatments [43,44]. Multiple cycles or high enzyme loadings are required to achieve significant CNC yield.…”

Cellulose Nano Whiskers as a Reinforcing Filler in Polyurethanes

“…Enzymatic-mediated production of cellulose nano whiskers was studied by Filson et al (2009). The highest yield of whiskers was obtained by treatment with 84 EGU of endoglucannase per 200 mg recycled pulp at 50 ˚C for 60 min assisted by microwave or conventional heating.…”

“…The mica was then attached to an AFM specimen disk and analyzed. In addition, particle size distribution, average molecular weight and zeta potential of cellulose nano whisker can also be determined by dynamic light scattering (Filson et al, 2009). As shown in the above tables, whiskers generally have a diameter of 3-20 nm and an aspect ratio of 20-60.…”

“…Softwood (SW) kraft pulp (Revol et al, 1994;Araki et al, 1998;Araki et al, 1999;Pu et al, 2007), SW sulfite pulp (Beck-Candanedo et al, 2005), hardwood (HW) ECF (elemental chlorine free) pulp (Beck-Candanedo et al, 2005), recycle pulp (Filson et al, 2009), cotton fiber (Revol et al, 1994;Dong et al, 1996;Dong et al, 1998;Araki et al, 2000;Hasani et al, 2008;Cao et al, 2009;Pei et al, 2010;Tang & Weder, 2010;Wang et al, 2010), sisal fiber (de Rodriguez et al, 2006;Tang & Weder, 2010), flax fiber (Cao et al, 2007), ramie fiber (Habibi et al, 2007;Habibi & Dufresne, 2008;Zoppe et al, 2009), wheat straw (Helbert et al, 1996), bamboo residue , bacterial microfibrils (Grunert & Winter, 2002), grass fiber (Pandey et al, 2009), tunicate cellulose (Favier et al, 1995;Angles & Dufresne, 2000;Sturcova et al, 2005;Ljungberg et al, 2006;Habibi et al, 2007;Siqueira et al, 2010;Tang & Weder, 2010), microcrystalline cellulose (MCC) Bondeson et al, 2006;Oksman et al, 2006;Bondeson & Oksman, 2007;Bai et al, 2009;Auad et al, 2010; have all been utilized as cellulose sources for whiskers. The most common preparation method employed is acid hydrolysis, including acid sulfuric and hydrochloric acid.…”