• Journal of the Korean Wood Science and Technology
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• v.40 no.2
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• pp.71-77
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• 2012

Cellulose nanowhisker (CNW) isolated from hardwood bleached kraft pulp (HW-BKP) using sulfuric acid hydrolysis was suspended in polyvinyl alcohol (PVA) and electrospun into composites nanofibers. Transmission electron microscopy (TEM) revealed the CNW to be rod-like, approximately of $16.1{\pm}4.6$ nm wide and $194{\pm}61$ nm long, providing an aspect ratio of about 12, with a particle size distribution range of $662.2{\pm}301.2$ nm. Uniform and high quality CNW/PVA composite nanofibers were successfully manufactured by the electrospinning method. As the CNW loading increases, the viscosity of CNW/PVA solutions shows a minimum at 1% CNW level which subsequently results in the smallest diameter (193 nm) of electrospun nanofibers. The average diameter of the nanofibers increased up to 284 nm with increasing CNW loading. These results suggest that the electrospinning method provides a great potential of manufacturing consistent and reliable nanofibers from CNW/PVA solution for the formation of scaffolds with potentials in future application.

• Elastomers and Composites
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• v.45 no.1
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• pp.51-57
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• 2010

Cellulose nanowhiskers (CNW) gamered increasing interest for their remarkable reinforcement of polymer composites. In this work, we were to produce cellulose whiskers from commercially available microcrystalline cellulose (MCC) by acid hydrolysis with sulfuric and hydrochloric acids. Electron microscopy found that each acid produced sililar cellulose crystals of diameters ranging from 20 to 30 nm and lengths ranging from 200 to 300 nm. Moreover, all samples showed remarkable flow birefringence through crossed polarization filters. Conductometric titration of CNW suspensions revealed that the sulfuric acid treated sample had a surface charge of between 140.00 mmol/kg and 197.78 mmol/kg due to sulfate groups, while that of the hydrochloric acid treated sample was undetectable. Thermogravimetric analysis showed that the thermal decomposition temperature and apparent activation energy (evaluated by Broido's method at different stages of thermal decomposition.) of H1-CNW - prepared by hydrolysis with hydrochloric acid - was higher than those of S1-CNW and S2-CNW - prepared by hydrolyzing MCC with sulfuric acid.