Surface-initiated PET-ATRP and mussel-inspired chemistry for surface engineering of MWCNTs and application in self-healing nanocomposite hydrogels.

A green strategy by integrating surface-initiated metal-free photoinduced electron transfer-atom transfer radical polymerization (PET-ATRP) with mussel-inspired polydopamine (PDA) chemistry, was used to fabricate multi-walled carbon nanotubes (MWCNTs)/poly(4-vinylpyridine) (P4VP) nanocomposites. Self-healing nanocomposite hydrogels were facilely designed with these nanocomposites through dynamic supramolecular interactions. Using mussel-inspired PDA chemistry from MWCNTs, nanocomposites (MWCNTs@PDA-P4VP) were successfully prepared by metal-free PET-ATRP with MWCNTs@PDA-Br as an initiator, rhodamine B as photocatalyst, 4-vinylpyridine (4VP) as monomer, respectively. Importantly, the obtained nanocomposite hydrogels had high mechanical strength (2.9 MPa), prior fracture strain (633.8%) and excellent self-healing property (90.6%). These methodologies will provide opportunities for the design of eco-functional materials or flexible biosensors.