Reusable gold nanorod/liquid crystalline elastomer (GNR/LCE) composite films with UV-triggered dynamic crosslinks capable of micropatterning and NIR actuation

The design and preparation of novel liquid crystalline elastomers (LCEs) are highly desirable for the development of smart soft materials with quick stimuli-responsive characteristics. In this work, we present a facile preparation strategy of near infrared (NIR)-responsive gold nanorod/liquid crystalline elastomer (GNR/LCE) composite films exhibiting fascinating re-shapeable and reusable properties. A random side-chain liquid crystalline copolymer containing biphenyl mesogens and cinnamate side groups has been prepared via ring-opening metathesis polymerization (ROMP), with the [2+2] (retro)cycloaddition of cinnamate groups triggered by various wavelength UV light serving as the reversible dynamic crosslinks for the construction of re-shapeable LCEs. The GNR/LCE composite films with uniformly doped monodisperse GNRs demonstrate remarkable photothermal effects and multi-mode NIR-driven macroscopic deformation capabilities. Furthermore, a single-layer dual-phase composite film composed of periodic micro-patterned monodomain (M) and polydomain (P) structures has been fabricated, which is promising for precise localized NIR-responsive actuation and fully photo-controlled LCE composite devices.