A Fascinating Metallo-Supramolecular Polymer Network with Thermal/Magnetic/Light-Responsive Shape-Memory Effects Anchored by Fe₃O₄ Nanoparticles

Two-way shape-memory polymers (2W-SMPs) show great potential in actuating applications such as robotics due to their reversibility; indeed, multiresponsive 2W-SMPs are more expected. Inspired by the fascinating adhesion effects of mussels, we herein describe a metallo-supramolecular poly­(ε-caprolactone) (PCL)-based network constructed around catechol chemistry, leading to excellent thermal/magnetic/light-responsive two-way shape-memory effects (2W-SME) as well as self-healing capacity. These hybrid networks get readily self-assembled upon metal coordination interaction between superparamagnetic iron oxide nanoparticles (Fe₃O₄ NPs) and catechol-telechelic PCL. The incorporation of Fe₃O₄ NPs may act as the strong netpoints which allow the networks with excellent thermal-responsive one-way (1W) and 2W-SME, due to the ability of the semicrystalline PCL segments to present both crystallization-induced elongation (CIE) and melting-induced contraction (MIC) under constant stress. As a multifunctional medium, moreover, it also endows the hybrids with the magnetic-responsive 2W-SME in an alternating magnetic field and the light-induced SME triggered by the near-infrared light. Thanks to the dynamic nature of this metal coordination interaction inspired by mussel, the target hybrid networks also showed good self-healing capability. A model of magnetic-triggered actuator was well-established, which allows to the material with interesting applications such as remote-control or intelligent magnetic-sensitive devices