A gas-plastic elastomer that quickly self-heals damage with the aid of CO₂ gas

Self-healing materials are highly desirable because they allow products to maintain their performance. Typical stimuli used for self-healing are heat and light, despite being unsuitable for materials used in certain products as heat can damage other components, and light cannot reach materials located within a product or device. To address these issues, here we show a gas-plastic elastomer with an ionically crosslinked silicone network that quickly self-heals damage in the presence of CO₂ gas at normal pressures and room temperature. While a strong elastomer generally exhibits slow self-healing properties, CO₂ effectively softened ionic crosslinks in the proposed elastomer, and network rearrangement was promoted. Consequently, self-healing was dramatically accelerated by ~10-fold. Moreover, self-healing was achieved even at -20 °C in the presence of CO₂ and the original mechanical strength was quickly re-established during the exchange of CO₂ with air.