Dual‐Stimuli‐Responsive Covalent Organic Framework‐Liquid Crystal Polymer Smart Actuator

Abstract Covalent organic frameworks (COFs) represent a novel class of crystalline porous polymers that is in the limelight of research on functional materials. Loading COFs into a polymer matrix combines the stimuli‐responsive behavior of COFs and shape integrity and processing easiness of polymers. However, multiple and complex responsiveness can hardly be realized by integrating COFs into an amorphous and inert polymer matrix. Herein, photothermal and solvent‐sensitive porphyrin COF is synthesized and incorporated into another functional liquid crystal polymers (LCPs) matrix, which has uniformly molecular alignment and is capable of performing reversible deformation in response to external stimulus. As a result, the COFs dispersed in LCP can act as photothermal agents and fluorescence motifs, endowing the COF‐doped LCP film with near‐infrared (NIR) light and solvent dual‐responsiveness. Moreover, thanks to the ordered molecular alignment of LCP, such stimulation can trigger multi‐model actuation of the polymer film by adjusting molecular aligning direction, finally, based on the novel multifunctional composite film, a bionic flower capable of reversibly blooming and closing response to NIR light and solvent vapors is prepared.