Ionic liquid-mediated technology to produce cellulose nanocrystals directly from wood.

Ionic liquid-mediated technology to produce cellulose nanocrystals directly from wood.

Carbohydrate polymers (2015-10-03)

Hatem Abushammala, Ingo Krossing, Marie-Pierre Laborie

ABSTRACT

We report for the first time the direct extraction of cellulose nanocrystals (CNCs) from wood by means of a 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]) treatment. A native cellulosic product could be recovered in 44% yield with respect to wood cellulose content. The product was analyzed for morphological (TEM, AFM, XRD), chemical (FTIR, (13)C CP/MAS NMR), thermal (DSC, TGA) and surface properties (Zeta potential, contact angle). These analyses evidenced the presence of partially acetylated (surface DS=0.28) nanocrystals of native cellulose I microstructure, with a crystallinity index of about 75% and aspect ratio of 65. Direct production of CNCs from wood is ascribed to the simultaneous capability of [EMIM][OAc] to (1) dissolve lignin in situ while only swelling cellulose, (2) decrease intermolecular cohesion in wood via acetylation, and (3) to catalyze cellulose hydrolysis.

MATERIALS

Product Number

Brand

Product Description

705551

Sigma-Aldrich

Hydrogen chloride solution, 3 M in cyclopentyl methyl ether (CPME)

717975

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Methanol, NMR reference standard

288306

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71687

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282979

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3-Ethyl-2,4-pentanedione, mixture of tautomers, 98%

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Acetyl bromide, 99%

84429

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18304

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401757

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372978

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316989

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2104

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24201

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