Mechanically Robust and Room-Temperature Self-Healing Biobased Conductive Elastomers with Polydopamine-Functionalized Segregated Structure

Abstract

Conductive elastomers integrating robust mechanical properties and room-temperature self-healing capability present great potential for advanced technologies, yet their fabrication remains challenging due to the inherent trade-off between strength and reparability, coupled with inadequate interfacial adhesion. We propose an innovative “one-stone-three-birds” strategy to address these challenges by developing supramolecular elastomer composites (SECs) through the incorporation of polydopamine (PDA) into a carboxylated cellulose nanofiber (CCNF)-reinforced oxidized natural rubber (ONR) system. The composite features a segregated architecture, where the ONR matrix is compartmentalized by the CCNF network with PDA localized within the CCNF phase. This strategic integration yields three major benefits: First, PDA enhances interfacial interactions between the ONR and CCNF, boosting mechanical robustness (15.33 MPa tensile strength, 834% elongation) while enabling remarkable ambient self-healing efficiency (87.5% recovery). Second, PDA’s excellent photothermal conversion facilitates light-activated, precise, and rapid self-healing and provides the SECs with promising thermoelectric properties. Third, PDA’s inherent adhesiveness allows for easy dip-coating of conductive materials onto the SECs surface to endow conductivity, resulting in flexible strain sensors with excellent sensitivity, reliability, and durability. Our innovative approach establishes a new paradigm in self-healing material design through molecular-level interfacial engineering and hierarchical structure control, simultaneously addressing critical challenges in mechanical robustness, dynamic reparability, and functional adaptability.