Transparent, Tough, and Self-Healable Elastomer Based on Dynamic Dual Cross-Linking of Coordination and Disulfide Bonds

Abstract

Tough and stretchable self-healing elastomers are highly desired for applications in wearable devices, soft robotics, and human motion detection. However, most elastomers that heal at room temperature suffer from poor mechanical properties. In this study, inspired by mussels, a dual cross-linked strategy that combines weak disulfide bonds and strong coordination bonds is proposed to solve the above-mentioned problems. The obtained transparent silicone elastomer shows high tensile stress (1.4 MPa), stretchability (2006%), toughness (14.7 MJ m −3 ), and excellent healing efficiency (97%) at room temperature. The outstanding performance of the silicone elastomer is attributed to the synergistic effects of coordination and disulfide bonds. In the dual cross-linked network, disulfide bonds are introduced as sacrificial bonds to endow the elastomer with excellent stretchability and self-healing property, and coordination bonds are conductive to improving robustness and elasticity. Given the good mechanical and healing property of the developed silicone elastomer, it enables the easy construction of flexible strain sensors with excellent electrical conductivity and sensing stability. Our study provides insights into the development of self-healable silicone elastomers for flexible electronics.

Bioactive Metal Ion-Coordinated Dynamic Hydrogel with Antibacterial, Immunomodulatory, and Angiogenic Activities for Infected Wound Repair

“…Moreover, metal–ligand coordination can provide a clever introduction of biofunctions into the hydrogels if bioactive metal ions or ligand biomolecules are used. , For example, the sulfhydryl ligand, a group commonly found in bioactive proteins and peptides, can spontaneously form coordination bonds with various metal ions. Furthermore, it has the unique ability to create dynamic covalent disulfide bonds among themselves, which can not only bolster the stability of the hydrogel but also ensure the retention of its dynamic properties. , In addition, there are also plenty of metal ions in the human body, which play a crucial role in regulating metabolism, maintaining life functions, and supporting tissue repair . For instance, silver ions (Ag + ) can effectively sterilize bacteria and promote wound healing by disrupting bacterial cell membranes and binding to bacterial proteins to inhibit DNA replication; zinc ions (Zn 2+ ) is a vital trace element in the human body that can regulate macrophage polarization toward the M2 phenotype and boosting the expression of anti-inflammatory cytokines to improve cell growth, differentiation, and accelerate tissue repair. − Therefore, the fabrication of an ECM-like dynamic hydrogel dressing through metal–ligand coordination is expected to easily integrate multiple bioactivities and efficiently accelerate infected wound healing.…”