Helical Fibers via Evaporation‐Driven Self‐Assembly of Surface‐Acylated Cellulose Nanowhiskers

Abstract

AbstractMany natural materials have helical or twisting shapes. Herein, we show the formation of helical fibers with the lengths of micrometers by the evaporation‐driven self‐assembly on silicon wafers of functionalized cellulose nanowhiskers (CNWs) with surface‐attached acyl chains. The self‐assembly process and the final helical structures were affected by parameters including the wettability of substrates, dispersing solvents, the amount of 10‐undecenoyl groups, the crystallinity, the dimension of CNWs, and the length of acyl chains. In particular, surface‐acylated CNWs with a certain amount of 10‐undecenoyl groups (ca. 3.52 mmol g−1), an appropriate crystallinity (ca. 40 %), a length of about 135 nm, and a diameter of around 4 nm, preferentially self‐assembled into explicit left‐handed helical fibers from their THF suspensions on wafers. Thus, we showed novel particular self‐assembly behaviors of surface‐acylated CNWs, and we expanded the materials spectrum for the construction of helical structures.