Near-infrared activation of semi-crystalline shape memory polymer nanocomposites

摘要

Recently, indirect activation of the shape memory effect has become an increasingly popular triggering modality for shape memory polymer biomaterials. Amongst the known methods for remote activation, near-infrared radiation (NIR) remains relatively unexplored, specifically for semicrystalline materials, which possess sharp thermal transitions. Herein, poly(ε-caprolactone) (PCL) networks were photo-polymerized from branched precursors doped with 150 nm surface modified gold nanoshells with a surface plasmon resonance of approximately 800 nm. The effect of nanoparticle loading on the thermal, mechanical, and shape memory properties of the PCL matrix were examined. The PCL nanocomposites exhibited excellent shape fixation and nearly quantitative shape memory recovery in response to low intensity NIR irradiation. Further, the heat dissipated by the irradiated nanocomposites to the surrounding medium was found to reach a maximum at biologically relevant temperatures. As such, this nanocomposite system represents a highly attractive candidate for many biomedical shape memory applications.