Octopus-inspired solvent-assisted rapid self-healing polydimethylsiloxane-polyurea elastomers

Abstract

Self-healing materials that can autonomously repair physical damage and restore mechanical properties have significant potential in advanced technologies, including flexible electronics and smart coatings. In this work, we synthesized poly(dimethylsiloxane)-polyurea (PDMS-IU_xMU_1-x) to study the effect of multiple hydrogen bonds on the mechanical and self-healing properties and found that improving the dynamics of strong hydrogen bonding is the key to breaking the trade-off between mechanical and self-healing properties. Inspired by the octopus, we introduced different solvents to improve the healing performance. Ultimately, the stiff PDMS-MU samples (1.18 MPa, 1282 %), which were difficult to heal at elevated temperatures, achieved a remarkable strength recovery (66.7 % in 10 min, 25 °C). We verified the effect of this strategy on other polymers and achieved rapid healing at ambient temperature (88 % in 10 min and 98.5 % in 3 h) and at −20 °C (98.9% in 24 h), surpassing many reported solvent-assisted healing materials. Moreover, our findings revealed that ethanol significantly improves the dynamics of hydrogen bonding, increases the mobility of polymer molecular chains, reduces the activation energy, and ultimately promotes healing. This research offers valuable insights into designing high-performance self-healing materials that are reprocessable and energy-efficient, addressing key challenges in the field and promoting the development of self-healing elastomers in flexible and wearable devices.