Silicone Elastomers with High‐Permittivity Ionic Liquids Loading

The most obvious challenge facing current dielectric elastomers (DEs) is the high driving voltages necessary to activate them, and so, an effective way to overcome this shortcoming is to increase their dielectric permittivity. Herein, high‐permittivity dielectric elastomer materials are prepared by synthesizing silicone elastomer loaded with ionic liquids (ILs). The influence of the structure and the amounts of ILs on the material properties is discussed, and important properties for material applications as DEs, such as dielectric permittivity, gel fraction, and mechanical properties, are also investigated. It is found that 1‐butyl‐3‐methylimidazolium hexafluoroantimonate (BmimSbF 6 ) is the most suitable IL for the given system. The dielectric permittivity of the material with 90 parts per hundred rubber (phr) BmimSbF 6 is 3.2 times higher than that of the pristine silicone elastomer, whereas the dielectric permittivity of pure silicone elastomer and elastomer loaded with ILs decreases in line with increased temperature in all cases. Young's modulus decreases in line with the increasing amount of BmimSbF 6 in the elastomer, as expected. A simpler figure of merit ( F * om ) for actuators is used, and F * om of the elastomer with a 90 phr IL loading is 10.40, thereby indicating that the material has a great advantage when used in actuators.