Reversible white-light actuation of carbon nanotube incorporated liquid crystalline elastomer nanocomposites

Abstract

We present single-wall carbon nanotube (SWCNT) incorporated liquid crystal elastomer (LCE) nanocomposites that demonstrate strong, reversible photoactuation. The matrix nematic LCE material possesses reversible thermal deformation, while SWCNTs perform photothermal energy conversion and local heat dissipation upon irradiation. The resultant SWCNT–LCE nanocomposites exhibit effective photoactuation not only by infrared (IR) irradiation, but also white light with an intensity on the order of 100 mW cm⁻². Rapid and reversible photo-induced strain was observed. The nanocomposite films contracted up to one third of the original length in several seconds under the irradiation of white light, and recovered to the original length in several seconds after the light source was switched off. Moreover, the nematic–isotropic transition temperatures of the SWCNT–LCE nanocomposites were evidently lower than that of the blank LCE by up to 19 °C.