Porous Liquid-Crystalline Networks with Hydrogel-Like Actuation and Reconfigurable Function

Angew Chem Int Ed Engl. 2022 Feb 21;61(9):e202116689. doi: 10.1002/anie.202116689. Epub 2022 Jan 17.

Abstract

A porous liquid-crystalline network (LCN), prepared by using a template method, was found to exhibit peculiar actuation functions. The creation of porosity makes the initially hydrophobic LCN behave like a hydrogel, capable of absorbing a large volume of water (up to ten times the sample size of LCN). When the amount of absorbed water is relatively small (about 100 % swelling ratio), the porous LCN displays anisotropic swelling in water and, in the same time, the retained uniaxial alignment of mesogens ensures a thermally induced shape change associated with a LC-isotropic phase transition. Combining the characteristic actuation mechanisms of LCN (order-disorder transition of mesogens) and hydrogel (water absorption), such porous LCNs can be explored for versatile stimuli-triggered shape transformations. Moreover, the porosity enables loading/removal/reloading of functional fillers such as ionic liquids, photothermal dyes and fluorophores, which imparts the porous LCN actuator with reconfigurable functions such as ionic conductivity, light-driven locomotion, and emissive color.

Keywords: Hydrogel-Like Swelling; Porous Liquid-Crystalline Network; Reconfigurable Function; Reversible Shape Change; Soft Actuator.