Symmetry breaking

Quantum mechanics

Self-assembly

Colloid

Engineering

Chemical physics

Nanoparticle

Metallurgy

Materials science

Nambu–Jona-Lasinio model

Cellulose

Lyotropic

Chemical engineering

Liquid crystalline

Physics

Nanotechnology

Crystallite

Mesophase

Nanocrystal

Chirality (physics)

Chemistry

Nanoscopic scale

Chiral symmetry breaking

Liquid crystal

Optoelectronics

Nature Communications

The transfer of chirality across length-scales is an intriguing and universal natural phenomenon. However, connecting the properties of individual building blocks to the emergent features of their resulting large-scale structure remains a challenge. In this work, we investigate the origins of mesophase chirality in cellulose nanocrystal suspensions, whose self-assembly into chiral photonic films has attracted significant interest. By correlating the ensemble behaviour in suspensions and films with a quantitative morphological analysis of the individual nanoparticles, we reveal an inverse relationship between the cholesteric pitch and the abundance of laterally-bound composite particles. These ‘bundles’ thus act as colloidal chiral dopants, analogous to those used in molecular liquid crystals, providing the missing link in the hierarchical transfer of chirality from the molecular to the colloidal scale.

Chiral self-assembly of cellulose nanocrystals is driven by crystallite bundles