A polycaprolactone/polydopamine nanocomposite with sunlight-induced shape memory effect and solid state plasticity

A facile photo-cured polycaprolactone (PCL)/polydopamine (PDA) nanocomposite is prepared via thiol-ene reaction. Owing to favorable light-to-thermal transfer of doped polydopamine nanoparticles (PDAPs) in composites, active photo-thermal actuation of the composite is achieved when subjected to simulated sunlight irradiation, the effects of sunlight intensity and PDAPs concentration on the composite's surface temperature are studied systematically. Solid state plasticity is also achieved by activating the dynamic transesterification reaction within the same polymer network. More importantly, the composite also features sunlight-induced plasticity under a light intensity of 960 mW cm(-2). Macroscopically, the flat permanent shape can be reconfigured to a new 3D permanent shape via simulated sunlight, and the reconfigured shape still exhibits excellent elasticity-based shape memory behaviors even after seven cycles of testing. Based on these special properties, the PCL/PDAPs composite is further used in the field of electronic devices. It is expected that the design of PCL-PDAPs composite can pave a simple pathway for the simplification of complex shapes and can be extended to fabricate light-operated actuators.