Rapid Near-Infrared Light Responsive Shape Memory Polymer Hybrids and Novel Chiral Actuators Based on Photothermal W18O49 Nanowires

Photoresponsive actuators are built by introducing oligo(ethylene glycol) (OEG)-modified W18O49 nanowires into cross-linked polyethylene glycol diacrylate (cPEGDA) polymer matrices. Due to the good compatibility, OEG-W18O49 NWs disperse well and increase the crystallinity of cPEGDA matrices even in high loading concentrations (4.0 wt%). The cPEGDA/W18O49 nanocomposites show efficient photothermal transition and rapid shape memory behaviors. They can raise the local temperature to 160 degrees C in only 8.5 s and recover the initial shape within 10 s. Making use of the broad and strong absorption property of W18O49, the cPEGDA/W18O49 NW actuators respond to both ultraviolet and near-infrared light and make contraction and bending motions. Furthermore, by utilizing oriented chain segments of the crystalline polymer and vector sum of shape recovery forces, the cPEGDA/W18O49 NW hybrid actuators exhibit stable helical deformation (right-handed and left-handed).