Development of completely dispersed cellulose nanofibers

Abstract

Plant cellulose fibers of width and length ∼0.03 mm and ∼3 mm, respectively, can be completely converted to individual cellulose nanofibers of width and length ∼3 nm and ∼1 µm, respectively, by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation under aqueous conditions and subsequent gentle mechanical disintegration of the oxidized cellulose in water. The obtained TEMPO-oxidized cellulose nanofibers (TOCNs) are new bio-based, crystalline nanomaterials with applications in the high-tech and commodity product industries. Sodium carboxylate groups, which are densely, regularly, and position-selectively present on the crystalline TOCN surfaces, can be efficiently ion-exchanged with other metal and alkylammonium carboxylate groups in water to control the biodegradable/stable and hydrophilic/hydrophobic properties of the TOCNs. TOCNs are therefore promising nanomaterials that can be prepared from the abundant wood biomass resources present in Japan. Increased production and use of TOCNs would stimulate a new material stream from forestry to industries, helping to establish a sustainable society based on wood biomass resources.

Use of cellulose nanofibers as a denture immersing solution

“…Recently, patents and commercial products concerning the industrialization of CNF have been proposed 14,16) . Moreover, CNF possess superior hydrophilic properties 16,17) . Therefore, the coating of the surface of a PMMA denture base with CNF might improve its surface wettability and enhance the denture retention in the oral cavity.…”

Isolation of Cellulose Nanofibers from Oryza sativa Residues via TEMPO Mediated Oxidation

“…HCl (2 M) was added to the suspension of oxidized cellulose to adjust the pH to 2 and the mixture was stirred at room temperature to convert the C 6 COONa groups to C 6 COOH groups. The carboxyl content of the pulp fibers was determined by potentiometric titrations where the fibers (0.1 g) were dispersed in water (20 ml) and titrated with NaOH (0.1 M) solution (Barbosa et al 2013;Isogai 2018;Rohaizu and Wanrosli 2017;Zhou et al 2018). The carboxyl content was calculated using the following formulae:…”

Mechanical and thermal properties of cellulose nanofiber composites with nanodiamond as nanocarbon filler

“…Cellulose is one of principal components in cell walls [1,2] and has been accepted as an architectural material and hull material since ancient times. Therefore, there is no doubt that cellulose materials are available from eco-friendly and sustainable resources; in addition, they are possess reliable and provide robust mechanical durability [3][4][5][6][7][8][9][10][11]. Recently, synthetic polymers originating from fossil fuels have been employed as alternatives to metals.…”

“…Various preparation methods of cellulose nanofibers have been reported; for example, mechanical grounding method, microfluidics method, chemically modified method and enzyme fibrillation [11,[44][45][46][47][48][49][50][51][52]. Particularly, the major chemical nanofibrillation methods are the 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)-mediated oxidation treatment reported by Isogai et al [6,9,44,51] and quaternary ammonium treatment using glycidyltrimethylammonium chloride (GMAC) reported by Ho et al [46,53,54] The functional groups and surface properties of cellulose nanofibers are controlled by these chemical nanofibrillation methods. For achieving effective reinforcements in nanocomposites, their high dispersion in aqueous media and strong interaction with nanofillers are significant.…”