Rapid photo-responsive self-healing cross-linked polyurea/ polydopamine nanocomposites with multiple dynamic bonds and bio-based rosin

The development of conventional thermo-responsive self-healing elastomer is hindered by two bottlenecks: i) longer repair time for damaged elastomers and ii) restricted sites for self-healing. In this study, fast near-infrared (NIR) light photo-responsive self-healing nanocomposites were fabricated by blending polydopamine (PDA) particles into cross-linked polyurea containing sextuple H-bonds (SHBs) and hinder urea bonds (HUBs). Strong interfacial interactions between PDA and polyurea fragments containing extensive H-bonds significantly enhanced the mechanical properties of the nanocomposites. Moreover, the rapid photoresponsive self-healing properties were provided by the excellent dynamic abilities of HUBs and the outstanding photothermal effect of PDA. Further, the deposition of Pt onto the elastomer surface created a conductive layer through chelation with PDA, thereby endowing the nanocomposites with the potential for strain sensor applications.