Self-healing Polymer Gel with Cascade-Responsive Properties

Abstract

Materials that exhibit cascade-responsive self-healing similar to that of living organisms can be of great practical value. However, developing them has been challenging. Herein, we demonstrate a polymeric material that can achieve cascade-responsive self-healing via a mechanical-force-triggered self-crosslinking reaction. Ferrocene is used as a mechanophore and its decomposition when the material is subjected to a mechanical force generates Fe³⁺, which forms a complex with catechol residues present in side chains; thus, forming a new network structure. This cross-linking results in a self-healing efficiency of 100 % after compression at 50 MPa for 5 min and standing for 72 h at room temperature. This strategy also provides the material with self-strengthening ability under repeated mechanical loading. The material exhibited the ability to resist the diffusion of micro cracks caused by high pressure in seawater. This study provides design principles for the construction of a new generation of intelligent bio-like self-healing materials.