Multi-Stimuli Responsive Carbon Nanotube Incorporated Polysiloxane Azobenzene Liquid Crystalline Elastomer Composites

In this work, aiming to combine thermal-induced LC-to-isotropic phase transition effect, azobenzene’s trans–cis tautomerization effect and the photothermal effect into one liquid crystalline elastomer (LCE) system to prepare a heat/UV/near-infrared(NIR) triple-stimuli-responsive LCE material, we design and synthesize a polysiloxane-based side-chain side-on azobenzene-containing LCE matrix embedded with 1 wt % single-walled carbon nanotubes, through Finkelmann’s two-step cross-linking process coupled with a uniaxial stretching technique. The multistimuli responsive behaviors of this LCE/CNT composite film are investigated under different external stimuli (heat, UV, NIR). The composite film can realize a reversible deformation between contraction and extension under heating/cooling cycles. Moreover, the composite film can perform an impressive three-dimensional deformation (bending) under UV-light irradiation. On the contrary, long wavelength light (NIR laser) forces the composite film into shrinking instea...