Cellulose Nanocrystals in Spherical Titania-Sol Microdroplet: From Dynamic Self-Assembly to Nanostructured TiO x /C Microsphere Synthesis

Cong Wang (1) , Erwan Paineau (2) , Hynd Remita (1) , Mohamed Nawfal Ghazzal (1)

1 ICP - Institut de Chimie Physique
2 LPS - Laboratoire de Physique des Solides

The study and control of cellulose nanocrystals (CNCs) self-assembly in spherical confinement remains a challenging and unexplored area. It is difficult to directly observe the self-organization of CNCs in such geometry. Herein, a dynamic observation of the selforganization process of CNCs in confined titania-sol microdroplet is reported. The isotropic to cholesteric transition undergoes nucleation, coalescence and migration of tactoids through two coalescence mechanisms, namely "head-to-tail" and "side-to-side" types. The solubility and self-organization of CNCs in titania-sol enable a successful transfer of the chiral (Ch) nematic structure into hybrid TiOx/C microspheres. TiOx/C microspheres show higher photocatalytic H2 generation compared to TiO2-P25. This work adds to the understanding of self-assembly process of CNCs in spherical geometry, and provides a fresh avenue to design nanostructured photoactive microspheres with unique Ch nematic structures.

Mots clés: cellulose nanocrystals; tactoids; self-organization; spherical confinement; cellulose nanocrystals

Domaines: Catalyse; Matériaux; Matière Molle [cond-mat.soft]

Cong Wang, Erwan Paineau, Hynd Remita, Mohamed Nawfal Ghazzal. Cellulose Nanocrystals in Spherical Titania-Sol Microdroplet: From Dynamic Self-Assembly to Nanostructured TiO x /C Microsphere Synthesis. Chemistry of Materials, 2021, 33 (17), pp.6925-6933. ⟨10.1021/acs.chemmater.1c01865⟩. ⟨hal-03367479⟩