Isolation and characterization of cellulose nanofibers from aspen wood using derivatizing and non-derivatizing pretreatments

Jonasson, Simon; Bünder, Anne; Niittylä, Totte; Oksman, Kristiina

doi:10.1007/s10570-019-02754-w

Cited by 60 publications

(39 citation statements)

References 55 publications

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“…The mechanical properties of the nanofibril network from the mechanically treated CNFs (NW-M) are lower than those of the chemically-mechanically treated (NW-CM) and chemically treated (NW-C) networks. A similar phenomenon has been observed previously (Jonasson et al 2020) and indicates the importance of pretreatment before homogenization to obtain enhanced network properties. Enhanced toughness, which was observed in the TW CNF networks, has also been observed for nanofibril networks of high-DP CNFs, both experimentally (Henriksson et al 2008;Fukuzumi et al 2013) and theoretically (Meng et al 2017).…”

Section: X-ray Diffractionsupporting

confidence: 88%

Comparison of tension wood and normal wood for oxidative nanofibrillation and network characteristics

et al. 2020

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Cellulose nanofibrils (CNFs) are top-down nanomaterials obtainable from abundant lignocelluloses. Despite recent advances in processing technologies, the effects of variations in the lignocellulose structure and composition on CNF isolation and properties are poorly understood. In this study, we compared the isolation of CNFs from tension wood (TW) and normal wood (NW) from Populus tremula (aspen). The TW has a higher cellulose content, native cellulose fibrils with a larger crystalline diameter, and less lignin than the NW, making it an interesting material for CNF isolation. The wood powders were oxidized directly by 2,2,6,6-tetramethylpiperidin-1-oxyl, and the morphology and mechanical behaviors of the nanofibril suspensions and networks were characterized. The TW was more difficult to fibrillate by both chemical and mechanical means. Larger nanofibrils (5–10 nm) composed of 1.2 nm structures were present in the TW CNFs, whereas the NW samples contained more of thin (1.6 nm) structures, which also comprised 77% of the solid yield compared to the 33% for TW. This difference was reflected in the TW CNF networks as decreased transmittance (15% vs. 50%), higher degree of crystallinity (85.9% vs. 78.0%), doubled toughness (11 MJ/m3) and higher elongation at break (12%) compared to NW. The difference was ascribed to greater preservation of the hierarchical, more crystalline microfibril structure, combined with a more cellulose-rich network (84% vs. 70%). This knowledge of the processing, structure, and properties of CNFs can facilitate the breeding and design of wood feedstocks to meet the increasing demand for nanoscale renewable materials. Graphic abstract

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Section: X-ray Diffractionsupporting

confidence: 88%

Comparison of tension wood and normal wood for oxidative nanofibrillation and network characteristics

et al. 2020

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“…In addition, previous results with CCIMI (treatment time of 4 h at 100°C) showed a significantly lower tensile strength compared to the current study ( Table 2, entry 3). 25 It should be noted that in Table 2, the mechanical properties of films with randomly oriented nanofibers are reported. Orientation-for example, by drawing-can significantly improve the mechanical properties of the films.…”

Section: Mechanical Properties Of Cnf Filmsmentioning

confidence: 99%

“…19,20 Nonmodifying methods (i.e., no or only minimal decrease in DP or alteration of cellulose structure) based on deep eutectic solvents (DESs) have recently been used for the sustainable production of CNFs. [21][22][23][24][25] In addition to DESs' use as nonmodifying pretreatment media, they can be harnessed as solvents for chemical derivatization 26,27 and as reagents 28 that can even be recycled 29 in CNF production. DESs are ionic liquid analogues that are obtained by the simple mixture of two or more components and can often be derived from green and bulk chemicals.…”

Section: Introductionmentioning

confidence: 99%

High-strength cellulose nanofibers producedviaswelling pretreatment based on a choline chloride–imidazole deep eutectic solvent

et al. 2020

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A deep eutectic solvent (DES) based on choline chloride and imidazole (CCIMI) was investigated for swelling of cellulose fibers prior to mechanical disintegration into cellulose nanofibers (CNFs). The dimensions of the DES treated and washed fibers were investigated after various treatment conditions (time, temperature, and cellulose consistency) using DES based on choline chloride-urea (CCUrea) and pure imidazole as references. Even mild treatment conditions (15 minutes at 60°C) with CCIMI increased the diameter of the fibers from 18.1 to 18.9 μm, and a maximum diameter of 19.9 μm was obtained after three hours at 100°C. Overall, CCIMI resulted in a higher degree of swelling compared to both references. In addition, pure imidazole caused a decrease in the degree of polymerization of cellulose, whereas cellulose degradation in CCIMI was negligible. The mechanical disintegration of CCIMI-treated fibers resulted in the production of CNF films with very good mechanical properties-specific tensile strength and work capacity being over 200 kNm kg −1 and 10 kJ kg −1 , respectively-whereas CNFs films produced using choline chloride-urea had notably lower values (182 kNM kg −1 and 7 kJ kg −1 , respectively). In addition, CNF films exhibited good oxygen barrier properties, even at an elevated relative humidity level (80%). CCIMI could be recycled without any effect on the mechanical properties of CNF films. The results presented here indicate CCIMI is a highly efficient pretreatment media for swelling and further nanofibrillation of cellulose, even at mild treatment conditions. † Electronic supplementary information (ESI) available: Fiber width and CWT at various concentrations, DRIFT spectra, photograph of CNF aerogels, and TGA curves. See

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“…The treatment has been studied in great depth in relation to delignified pulps from a variety of sources [ 6 ]. It has also been demonstrated that feedstock containing lignin, such as thermomechanical pulp [ 7 ], hemp [ 8 ] and wood [ 9 ], can be simultaneously delignified and carboxylated using the treatment. The relation between these procedures and nanofibrillation is complex where CNFs with residual lignin are attainable despite substantial carboxylation [ 10 , 11 ].…”

Section: Introductionmentioning

confidence: 99%

“…The associated novelty includes highlighting TEMPO-oxidation as a metric of fibrillation suitability for raw wood with variation in lignin content, something which could be applicable to commercial endeavors where TEMPO-oxidation is an attractive prospect in obtaining CNFs. Direct TEMPO-oxidation of wood has only recently been the subject of few dedicated studies [ 9 , 13 ]. These studies were furthermore showcasing one type of wood whereas the study presented herein aims to explore an additional factor of wood characteristics.…”

Section: Introductionmentioning

confidence: 99%

The Effect of High Lignin Content on Oxidative Nanofibrillation of Wood Cell Wall

et al. 2021

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Wood from field-grown poplars with different genotypes and varying lignin content (17.4 wt % to 30.0 wt %) were subjected to one-pot 2,2,6,6-Tetramethylpiperidin-1-yl)oxyl catalyzed oxidation and high-pressure homogenization in order to investigate nanofibrillation following simultaneous delignification and cellulose oxidation. When comparing low and high lignin wood it was found that the high lignin wood was more easily fibrillated as indicated by a higher nanofibril yield (68% and 45%) and suspension viscosity (27 and 15 mPa·s). The nanofibrils were monodisperse with diameter ranging between 1.2 and 2.0 nm as measured using atomic force microscopy. Slightly less cellulose oxidation (0.44 and 0.68 mmol·g−1) together with a reduced process yield (36% and 44%) was also found which showed that the removal of a larger amount of lignin increased the efficiency of the homogenization step despite slightly reduced oxidation of the nanofibril surfaces. The surface area of oxidized high lignin wood was also higher than low lignin wood (114 m2·g−1 and 76 m2·g−1) which implicates porosity as a factor that can influence cellulose nanofibril isolation from wood in a beneficial manner.

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Isolation and characterization of cellulose nanofibers from aspen wood using derivatizing and non-derivatizing pretreatments

Cited by 60 publications

References 55 publications

Comparison of tension wood and normal wood for oxidative nanofibrillation and network characteristics

Comparison of tension wood and normal wood for oxidative nanofibrillation and network characteristics

High-strength cellulose nanofibers producedviaswelling pretreatment based on a choline chloride–imidazole deep eutectic solvent

The Effect of High Lignin Content on Oxidative Nanofibrillation of Wood Cell Wall

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