Improving Durability of Silicone Rubber Dielectric Elastomer Composite by Constructing Covalent‐Bonds Between the Surface‐Modified Silica and Matrix

The inherent viscoelastic behaviors of dielectric elastomers (DEs), such as creep and hysteresis, are important for their long‐term service stability and energy efficiency in cyclic applications. In this work, a constrained interface between dielectric filler and silicone rubber matrix was constructed by modifying nano‐silica surface with vinylmethyl dimethoxysilane (VMDMS). By the co‐crosslinking reaction among the vinyl groups of modified nano‐silica and polymethylvinylsiloxane (PMVS) matrix, the polymer chain mobility was restricted and the filler dispersion was improved. The as‐obtained VMDMS@SiO 2 /PMVS nanocomposites exhibited remarkably enhanced compressive creep as low as 0.25%, which was 86% lower than that of SiO 2 /PMVS nanocomposite. Furthermore, the constrained interface also provided excellent dielectric stability after creep and minimized hysteresis loss during cyclic loading. This study presents an effective interfacial design strategy for developing durable and reliable DEs with suppressed viscoelasticity, which has the potential for applications in soft robotics and energy harvesting.