Nature uses nanocomposites for a wide range of applications. In the squid beak, the degree of crosslinking is varied along its length, resulting in a mechanical gradient that connects the stiff tip to soft body tissues. We have designed polymer/cellulose nanocrystal (CNC) nanocomposites to mimic the architecture and function of the squid beak. Using photoinduced crosslinking chemistry, we control the degree of crosslinking between the CNCs themselves, the CNCs and the matrix polymer, and in the matrix polymer. In the dry state, strong hydrogen bonding interactions between adjacent CNCs reinforce the percolating filler network, so only a small mechanical contrast is observed between crosslinked and uncrosslinked samples. When the films are exposed to water, the noncovalent interactions are disrupted, resulting in a significant mechanical contrast determined by the covalent crosslinks. By controlling the UV exposure time, we show that a mechanical gradient that spans over 2-orders of magnitude in stiffness can be achieved. This presentation focuses on our latest results with these materials.

Bio-inspired mechanical gradient nanocomposites

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.