Interfacial engineering of polydimethylsiloxane based dielectric elastomers with excellent electromechanical properties via incorporating polyphenol encapsulated multiwalled carbon nanotube.

The paradox of obtaining dielectric elastomers (DEs) with both low modulus and high‐dielectric properties has long been puzzling researchers in this field. To solve this problem, a preliminary attempt is made here by solution compounding polyphenol nanoparticles modified multiwalled carbon nanotube (PNs@MWCNT) with polydimethylsiloxane (PDMS) to obtain PDMS based DEs with excellent electromechanical properties. The PNs layer can improve the interfacial interaction between MWCNT and PDMS probably through interfacial hydrogen bonding, thus improving the dispersion of PNs@MWCNT in PDMS. Compared with pure MWCNT filled PDMS nanocomposites, despite the hardening effect brought by the filler network, a softening effect (i.e., decreased cross‐linking) by the finer filler‐dispersion enhances in PNs@MWCNT/PDMS, resulting in lower moduli. Meanwhile, the as‐prepared PNs@MWCNT/PDMS composites exhibit high permittivity, low‐dielectric loss and high‐breakdown strength. Finally, the PNs@MWCNT/PDMS nanocomposites show excellent electromechanical properties with a largest actuated strain of 7.4% at a breakdown strength of 13.1 kV/mm, which is 2.2 times that (3.3%@13.3 kV/mm) of MWCNT/PDMS and 3.9 times that (1.9%@18.8 kV/mm) of neat PDMS. [ABSTRACT FROM AUTHOR]