Roll-to-roll fabrication of cellulose nanocrystal-poly(vinyl alcohol) composite coatings with controlled anisotropy
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Date
2018-11
Journal Title
Journal ISSN
Volume Title
Publisher
Cellulose
Abstract
Cellulose nanocrystal (CNC) composite coatings may impart many benefits in packaging, electronic, optical, etc. applications, however, large-scale cellulose coating production is a major engineering challenge. A versatile roll-to-roll reverse gravure process for the manufacture of cellulose nanocrystal-poly(vinyl alcohol) (CNC–PVA) coatings on a flexible polymer substrate was investigated in the present work. CNC content was varied from 0 to 100% to determine the effect of CNC concentration on coating anisotropy. Coatings were characterized by polarized light microscopy, UV–Vis spectrophotometry, cross-hatch adhesion testing and optical profilometry. This method produced uniform, highly transparent coatings with surface roughness less than 100 nm for all CNC–PVA weight ratios examined. The isotropic-anisotropic coating transformation was observed above 50% CNC, with a maximum anisotropy at 70% CNC along the shear direction. Anisotropic CNC–PVA coatings exhibited increased water vapor barrier performance due to the increased CNC packing and density.
Description
Keywords
Anisotropy, Cellulose nanocrystals, Poly(vinyl alcohol), Roll-to-roll, Transparency
Citation
Chowdhury, R.A., Clarkson, C., Apalangya, V.A. et al. Cellulose (2018) 25: 6547. https://doi.org/10.1007/s10570-018-2019-5