Efficient Cleavage of Strong Hydrogen Bonds in Cotton by Deep Eutectic Solvents and Facile Fabrication of Cellulose Nanocrystals in High Yields

Abstract

The content of cellulose in biomass is important for producing nanocellulose in high yields. Cotton fibers containing ultrahigh purity (∼95%) cellulose are ideal feedstock for nanocellulose production. However, the presence of strong hydrogen bonding between the cellulose chains limits the use of cotton fibers for the production of nanocellulose in a facile and mild process. Here, efficient cleavage of the strong hydrogen bonds in cotton and ultrafast fabrication of cellulose nanocrystals (CNCs) with a high yield of 74.2% were first realized through a 3 min microwave-assisted deep eutectic solvent pretreatment and a subsequent high-intensity ultrasonication process. The obtained CNCs had diameters of 3− 25 nm, and lengths ranged between 100 and 350 nm. The CNCs also displayed a relative crystallinity of 82%, and the thermal degradation temperature started from 320 °C. The study provides a green and efficient method for the mass production of cotton CNCs, and is expected to contribute to improving the refinery utilization of cotton feedstock.

Direct sulfation of cellulose fibers using a reactive deep eutectic solvent to produce highly charged cellulose nanofibers

“…In addition, previously significant decrease in the DP has been observed when cellulose treated with acidic DES (Sirviö et al 2016). Although hydrolysis of cellulose during the chemical modification prior CNFs production can help the mechanical fibrillation and thus liberation of nanosized cellulose, it is not prerequisite, as it has been previously reported that even use of non-hydrolytic DES can help the nanofibrillation of natural fibers (Sirviö et al 2015c;Liu et al 2017). It should be noted that due to the significant chemical modification of cellulose with DES, the DP values calculated be limiting viscosity method should taken more as guideline than an absolute values.…”

“…DESs have been studied as solvents (Gutiérrez et al 2010;Zdanowicz et al 2016), reagents (Azizi and Alipour 2015), and catalysts (Wang et al 2015) in organic synthesis and biomass treatment. Recently, a number of studies have emerged in which DESs are used as a solvent for cellulose derivatization (Abbott et al 2005(Abbott et al , 2006Park et al 2013;Willberg-Keyriläinen et al 2017) and for the production of various types of nanocelluloses (Sirviö et al 2015c(Sirviö et al , 2016Selkälä et al 2016;Hosseinmardi et al 2017;Liu et al 2017). A reactive DES has also been demonstrated in production of a derivatized, alkaline-soluble cellulose (Sirviö and Heiskanen 2017).…”

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

“…Then the anionic CNFs could be obtained through the followed microfluidization of carboxylated ground wood pulp. A microwave-assisted DES pretreatment method for fast CNCs production was proposed by Liu and coworkers [235]. It took only a little time (not more than 3 min) for the pretreatment of cotton, and then a high-intensity ultrasonication process was adopted.…”

Fabrication of regenerated cellulose nanoparticles by mechanical disintegration of cellulose after dissolution and regeneration from a deep eutectic solvent

“…25,26 Recently, DESs have been utilized in the production of CNFs [27][28][29][30] and CNCs. 31,32 In this study, a DES based on guanidine hydrochloride and anhydrous phosphoric acid was used to dissolve cellulose at room temperature. Dissolving pulp and microcrystalline cellulose were studied as cellulose sources.…”