Conductive Fibres Constructed on Fully Self-Healable Elastomer Fibres via an Electrospinning Approach

Abstract

Self-healing polymer recently emerged as one of the most promising fields for the development of sustainable, tough and flexible wearable optoelectronic devices. However, the development of intrinsic self-healing polymer fibres faces challenges because of fibres significant surface energy, resulting in high susceptibility to rapid intermolecular reaction. Herein, we synthesized a polypropylene glycol-based self-healing polymer with urea and urethane polar group for electrospinning. Vis-à-vis of their thin-film counterpart, polymer chains geometrical confinement in fibres has led the material to exhibit higher stiffness while maintaining sufficient flexibility. Such characteristic endowed our self-healing fibre with mechanical toughness up to 27 ± 1.1 MJ.m-3 at a stretching rate of 100 mm.min-1, and a toughness of 27 ± 1.5 MJ.m-3 at 100 mm.min-1 after a self-healing time of 6 hours through chain relaxation and H-bond network reconstruction. As a proof-of-concept, we fabricated a fully self-healable conductive fibre, with an initial conductivity of 1.0 × 105 S.m−2 and stretchability up to 700 %. Multi-walled carbon nanotubes deposition on top of self-healing fibre enabled to sustain polymer chain flowability and sustain significant conductivity even after crack repair, which enabled integration into a capacitive sensor device.