Surface Engineering of Porous Carbon for Self-Healing Nanocomposite Hydrogels by Mussel-Inspired Chemistry and PET-ATRP

In this work, surface-functionalized microcapsules from porous carbon nanospheres (PCNs) were successfully prepared by mussel-inspired chemistry with polydopamine (PDA) and metal-free photoinduced electron transfer-atom transfer radical polymerization (PET-ATRP). These functional microcapsules are introduced into self-healing hydrogels to enhance their mechanical strength. The PCNs synthesized by a simple soft template method are mixed with linseed oil for loading of the biomass healing agent, and the microcapsules are first prepared by coating PDA. PDA coatings were used to immobilize the ATRP initiator for initiating 4-vinylpyridine on the surface of microcapsules by PET-ATRP. Using these functional microcapsules, the self-healing efficiency was about 92.5% after 4 h at ambient temperature and the healed tensile strength can be held at 2.5 MPa with a fracture strain of 625.2%. All results indicated that the surface-functionalized microcapsules for self-healing hydrogels have remarkable biocompatibility and mechanical properties.