Facile Preparation and Study of Self-healing Water-absorbing Expanding Elastomers.

The absorbent expansion elastomer plays a crucial role in engineering sealing and holds a promising future in this field as infrastructure continues to develop. Traditional materials have their limitations, especially when used in large construction projects where the integrity and reliability of the material are of utmost importance. In this work, a self-healing water-absorbing expansion elastomer was developed for continuous production at a large scale to monitor the sealing conditions of massive infrastructure projects. At room temperature, the material exhibited a repairing efficiency of 57.77% within 2 h, which increased to 84.02% after 12 h. This extended reaction time allowed for effective repairs when defects were detected. The material's strength reached approximately 3 MPa, making it suitable for a wide range of applications. The volume expansion rate of the material reached 200-400% for effective sealing, and the fictionalization of the packing made it have a good external force sensing effect and prevent heat build-up effect. The conductive detection performance of the absorbent expansion elastomer was improved by utilizing triple self-healing strategies, including dipole-dipole interaction, ion cross-linked network, and externally-aided restoration materials.

Self-Healing Flexible Sensor Based on Epoxidized Natural Rubber with the Synergistic Effect of Coordination and Hydrogen Bonds.

The use of highly tensile and self-healing conductive composites has gained considerable interest due to their wide range of applications in healthcare, sensors, and robotics. Epoxidized natural rubber (ENR), known for its ability to undergo highly reversible deformation, can be utilized in strain sensors to effectively transmit a broader range of signal changes. In this study, we introduced a self-healing ENR composite specifically designed for high-strain sensors. The rubber molecular chains were enhanced with hydrogen bonds and metal coordination bonds, allowing the matrix material to autonomously repair itself through these interactions. Following a repair period of 12 h at 45 °C, the composites achieve a repair efficiency exceeding 90%. Furthermore, by incorporating conductive fillers into the matrix using multistage layering, the resulting composite has good electrical conductivity, thermal conductivity, and hydrophobicity. In addition, this composite presents good sensitivity even at large strain (strain in the range of 50-200%, GF = 7.65). In conclusion, this self-healing nanocomposite, characterized by its high strain sensitivity, holds immense potential for various strain sensor applications.