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Hydrophobic cellulo...
Hydrophobic cellulose nanocrystals modified with quaternary ammonium salts
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- Salajková, Michaela (author)
- KTH,Biokompositer,Wallenberg Wood Science Center
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- Berglund, Lars (author)
- KTH,Biokompositer,Wallenberg Wood Science Center
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- Zhou, Qi (author)
- KTH,Fiber- och polymerteknologi,Wallenberg Wood Science Center
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(creator_code:org_t)
- Royal Society of Chemistry (RSC), 2012
- 2012
- English.
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In: Journal of Materials Chemistry. - : Royal Society of Chemistry (RSC). - 0959-9428 .- 1364-5501. ; 22:37, s. 19798-19805
- Related links:
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Subject headings
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- An environmentally friendly procedure in aqueous solution for the surface modification of cellulose nanocrystals (CNCs) using quaternary ammonium salts via adsorption is developed as inspired by organomodified layered silicates. CNCs with a high carboxylate content of 1.5 mmol g(-1) were prepared by a new route, direct hydrochloric acid hydrolysis of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized nanofibrillated cellulose from a softwood pulp, and characterized by atomic force microscopy (AFM) and X-ray diffraction (XRD). Four quaternary ammonium cation surfactants bearing long alkyl, phenyl, glycidyl, and diallyl groups were successfully used to modify CNCs carrying carboxylic acid groups as characterized by Fourier transform infrared spectroscopy (FTIR). The modified CNCs can be redispersed and individualized in an organic solvent such as toluene as observed by scanning transmission electron microscopy (STEM). One may envision removing excess surfactant to obtain CNC with a monolayer of surfactant. The toluene suspension of the modified CNCs showed strong birefringence under crossed polars but no further chiral- nematic ordering was observed. The model surface prepared by the CNCs modified with quaternary ammonium salts bearing C18 alkyl chains showed a significant increase in water contact angle (71 degrees) compared to that of unmodified CNCs (12 degrees). This new series of modified CNCs can be dried from solvent and have the potential to form well-dispersed nanocomposites with non-polar polymers.
Subject headings
- NATURVETENSKAP -- Kemi -- Polymerkemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Polymer Chemistry (hsv//eng)
Keyword
- Tempo-Mediated Oxidation
- Radical Polymerization
- Native Cellulose
- Polyelectrolyte Multilayers
- Nanocomposite Materials
- Surface Oxidation
- Organic-Compounds
- Whiskers
- Adsorption
- Fibers
Publication and Content Type
- ref (subject category)
- art (subject category)
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