Self-healing materials
Self-healing materials, capable of regaining structural integrity and functionality, find broad application across industries including coatings, civil engineering, and electronics. While much attention has been given to restoring mechanical integrity, achieving self-healing of functionality presents greater challenges, particularly in reconstructing micro/nanostructures post-failure. Among functional properties, conductivity stands out, with examples including viscoelastic polymers filled with conductive particles.
The predominant method for fabricating self-healing electrical conductors involves embedding conductive fillers within a self-healing polymer matrix, commonly utilizing carbon materials like carbon black, graphene, or carbon nanotubes for their cost-effectiveness, lightweight, and relatively high conductivity. Autonomous healing mechanisms rely on interactions such as metal-ligand coordination, H-bonding, π-π stacking, and dynamic covalent bonding, characterized by low dissociation activation energy.
Successful implementation hinges on filler mobility within the polymer matrix and polymer chain mobility, requiring operating temperatures above the polymer's glass transition temperature. Consequently, these materials exhibit viscoelastic behavior, necessitating consideration of relaxation processes, rheological properties, and electromechanical behavior to define device limitations and ensure functionality. Our research primarily focuses on elucidating the mechanism of self-healing through mechanical spectroscopy, defining limitations, and applying insights to real electronic devices.
Selected publications
Milkin, Pavel; Zhanbassynova, Ainur; Ionov, Leonid
Superelastic, soft, stress-healable, recyclable conductive materials
in Composite Structures volume 327 (2024)
doi:10.1016/j.compstruct.2023.117709 ...
Milkin, Pavel; Danzer, Michael A.; Ionov, Leonid
Self-Healing and Electrical Properties of Viscoelastic Polymer-Carbon Blends
in Macromolecular Rapid Communications volume 43 (2022) issue 19
doi:10.1002/marc.202200307 ...