Title
Hardwood cellulose nanocrystals: multi-layered self-assembly with evidence of circular and distinct nematic pitch
Authors
LE VAN HAI YUNG BUM SEO and SRIKANTH NARAYANAN

Received It is our honor to dedicate this paper to Prof. Bogdan C. Simionescu, in recognition of his excellent life-long contribution to science.
Published Volume 52 Issue 7-8 July-August
Keywords cellulose nanocrystal, circular self-assembly, multi-layered, chiral nematic pitch, FE-SEM

Abstract
In this study, the formation of a self-assembly pattern and the nematic pitch of cellulose nanocrystals (CNCs) have been investigated first in a liquid state via Optical Microscopy (OM) and then in a dry state using Field Emission Scanning Electron Microscopy (FE-SEM). Furthermore, the surface characteristics of self-assembly patterns of hardwood bleached kraft pulp cellulose nanocrystals (HW-CNCs) were investigated under FE-SEM. HW-CNCs had a rod-like structure with a length of 202 + 52 nm and width of 14.9 + 3.9 nm. The circular patterns of self-assembled layers, with a differential area ranging from 3.0 μm to 30 μm, were evident. Furthermore, the HW-CNC thin film showed a left hand twist and a self-ordering structure. Such characteristics of CNCs open substantial possibilities for building bio based three-dimensional (3D) nanostructures or 3D nanoengineering materials. In this work, we have demonstrated the self-assembly of CNCs in multi-layers with circular patterns and distinct nematic pitch.