Creation of a new material stream from Japanese cedar resources to cellulose nanofibrils

Abstract

a b s t r a c tJapanese cedar is one of the most abundant plantation softwoods in Japan, although it is not effectively utilized as a wood resource. Japanese cedar cellulose was isolated and subjected to one-pot catalytic oxidation and reduction with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and NaBH 4 , respectively. The TEMPO-oxidized and NaBH 4 -reduced Japanese cedar celluloses (TOCs-NaBH 4 ) had carboxylate content of up to 1.4 mmol/g and viscosity-average degrees of polymerization from 2000 to 3000. The X-ray diffraction patterns of the TOCsNaBH 4 showed that the crystal widths were~3 nm, indicating that the C6-OH groups present on the crystalline cellulose microfibril surfaces were selectively oxidized to C6-carboxylate groups. When the TOCs-NaBH 4 with carboxylate content of 0.9-1.4 mmol/g were mechanically disintegrated in water, transparent TEMPO-oxidized cellulose nanofibril (TOCN) dispersions were obtained. The lengths of the TOCNs, determined from their atomic force microscopy images, varied from 800 to 1500 nm, depending on the oxidation conditions. The TOCNs prepared from Japanese cedar cellulose have an average of high aspect ratios (N300), which is greater than that (~150) prepared from wood pulp and thus advantageous.

Viscoelastic Properties of Core–Shell-Structured, Hemicellulose-Rich Nanofibrillated Cellulose in Dispersion and Wet-Film States

“…The largest thickness along each individual fibril was taken as the true fibril thickness, and the arithmetic mean thicknesses d a and weighted mean thicknesses d w of the NFCs were then calculated in the same way as the L a and L w values, respectively. The neutral sugar compositions of the NFC samples were determined using a high-performance liquid chromatography system at 50 °C . The X-ray diffraction (XRD) patterns of the NFC samples were recorded by the reflection method using a Rigaku RINT 2000 instrument with monochromator-filtered Cu Kα radiation (λ = 0.15418 nm) at 40 kV and 40 mA, and the crystal thicknesses d c of the (2 0 0) plane were calculated using Scherrer’s equation …”

“…The neutral sugar compositions of the NFC samples were determined using a high-performance liquid chromatography system at 50 °C. 54 The X-ray diffraction (XRD) patterns of the NFC samples were recorded by the reflection method using a Rigaku RINT 2000 instrument with monochromator-filtered Cu Kα radiation (λ = 0.15418 nm) at 40 kV and 40 mA, 8 and the crystal thicknesses d c of the (2 0 0) plane were calculated using Scherrer's equation. 55 ■ RESULTS AND DISCUSSION Characterization of NFCs.…”

Flexible and sensitive piezoresistive electronic skin based on TOCN/PPy hydrogel films

“…The chemical methods are to introduce charged groups on cellulose fibrils, and use the repulsion force between the same charges to obtain the separation of nanofibrils. Among them, the common and effective method is 2,2,6,6‐tetramethylpiperidinyl‐1‐oxyl (TEMPO)‐catalyzed oxidation 40 . The TEMPO‐oxidized cellulose nanofibril (TOCN) contains a large amount of carboxylic acid on the surface, and the monodisperse cellulose nanofibril is realized by the repulsion between the same charges 41 .…”

Antifreezing ionotronic skin based on flexible, transparent, and tunable ionic conductive nanocellulose hydrogels

“…Preparation of aqueous TOCN dispersion and ionic solution TEMPO-oxidized cellulose (TOC) was prepared by the TEMPO/NaBr/NaClO system with NaClO content of 5.0 mmol g − 1 -cellulose in aqueous solution at pH 10 followed by addition of 1 wt% NaBH 4 to convert the small amounts of C6-aldehydes and C2/C3-ketones to be complete hydroxyl groups following the previously reported method (Shi et al 2015;Takaichi et al 2014). The obtained TOC was washed with deionized water until neutral.…”