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 instead
of bending. Most importantly, the shape transformations (three-dimensional
bending vs two-dimensional shrinking) of this novel shape memory material
can be tuned by the light wavelength (UV vs NIR), which might endow
this LCE material with potential applications in control devices and
logic gate devices, etc.
The first example of a calamitic mesogenic NIR absorbing organic dye YHD796 is reported. The corresponding homogeneously-aligned LCE/YHD796 composite film can perform a fully reversible NIR-stimulated contraction/expansion response.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.