Watching Paper Dry: Making Photonic Structures from Cellulose Nanocrystals

Professor Mark MacLachlan

Abstract:
Cellulose nanocrystals (CNCs) obtained from paper or cotton are of great interest for many applications.1 In water, CNCs spontaneously form a chiral nematic lyotropic liquid crystalline phase, which can be preserved in dried films. The helicoidal structural organization of the CNCs in these films resembles the Bouligand structure of chitin found in crabs and other arthropods, and leads the films to be iridescent.2

In 2010, we reported that this liquid crystalline phase of CNCs can be used to template mesoporous silica with chiral nematic order.3 Since then, we have extended this concept to create diverse photonic materials,4 including elastomers that change colour when stretched and pressed,5 and recyclable shape-memory polymers with photonic properties.6 In this talk, I will discuss our team’s recent progress using CNCs as a template for the construction of new materials and our efforts to better control the self-assembly process by watching CNCs dry.

References:
1 Habibi,Y.; Lucia, L. A.; Rojas, O. J. Chem. Rev. 2010, 110, 3479.
2 Revol, J.-F.; Godbout, L.; Gray, D. G. J. Pulp Pap. Sci. 1998, 24, 146.
3 Shopsowitz, K.E.; Qi, H.; Hamad, W.Y.; MacLachlan, M.J. Nature 2010, 468, 422.
4 Tran, A.; Boott, C. E.; MacLachlan, M. J. Adv. Mater. 2020, 32, 1905876.
5 Boott, C. E.; Tran, A.; Hamad, W. Y.; MacLachlan, M. J. Angew. Chem. Int. Ed. 2020, 59, 226.
6 Boott, C. E.; Soto, M. A.; Hamad, W. Y.; MacLachlan, M. J. Adv. Funct. Mater. 2021, in press.

Host: Dr Mamatha Nagaraj