Enhanced electromechanical properties of natural rubber via the synergistic effect of poly(catechol/polyamine) modification and Ag deposition on TiO2 nanoparticles

Owing to their fast response, high efficiency, and large deformation , dielectric elastomer actuators (DEAs) are promising candidates for application in the fields of artificial muscles, sensors, and soft robots . With the aid of the large actuated strains of natural rubber (NR) at a relatively low driving voltage , titanate oxide (TiO 2 ) nanoparticles (NPs) modified by poly(catechol/polyamine) (PCPA) and deposited by Ag NPs were prepared (labeled as TiO 2 –PCPA–Ag). Due to the synergistic effect of the enhanced interfacial polarization obtained through PCPA modification and Ag NP micro-capacitors, the dielectric constant of the TiO 2 –PCPA–Ag–NR composites increased. In addition, the flexible PCPA endowed the composites with low elastic modulus , resulting in enhanced electromechanical properties . Thus, the NR composites filled with 10 phr TiO 2 –PCPA–Ag NPs exhibited the highest actuated strain of 8.86% at an electric field of 55.94 kV/mm, which is 2.1 times of pure NR (4.30%) at 55 kV/mm. The design of the NR composites proposed in this work via the synergistic effect of an organic layer and metal NPs will play a guiding role in the preparation of novel DEAs, which could meet future requirements for the development of actuators.