Loading ZIF‐67 onto carbon nanotubes in percolative nanocomposites towards improved dielectric performance

A great deal of attention is being paid to the application of polymer dielectric elastomers because of the advantages of low cost, facile fabrication, and high operating voltage. However, their development is often limited by mutually exclusive multifunctional properties such as high dielectric constant, high breakdown strength, and low dielectric loss. Therefore, for dielectric elastomer actuators, developing materials with enhanced dielectric properties and breakdown strength is an urgent need. In this work, we present CNT‐ZIF, a nanofiller obtained through the in‐situ growth of zeolitic imidazolate framework (ZIF)‐67 on the surface of carbon nanotubes (CNT), which was added to a synthesized polydimethylsiloxane (PDMS) matrix to obtain a composite with high dielectric constant and low dielectric loss. The CNT‐ZIF/PDMS composite containing 1.93 vol% of CNT‐ZIF exhibits an enhanced dielectric constant of 35.4 at 100 Hz, which is 11 times higher than that of the pure matrix and 1.58 times higher than that of the CNT/PDMS composite, meanwhile the loss is only 0.06. This value is deemed suitable for application in elastomer actuators. Therefore, this work can be regarded as one of the strategies for designing percolative dielectric composites. Highlights ZIF‐CNT nanofiller with excellent dispersion in the PDMS matrix has been prepared. The ZIF‐CNT/PDMS composites show enhanced dielectric properties at 100 Hz. The mechanism of improving dielectric properties is systematically investigated using the classical Cole‐Cole model and the percolation theory.