Fabrication of dielectric elastomers with improved electromechanical properties using silicone rubber and walnut polyphenols modified dielectric particles

In this work, polyphenolic extract from walnut green husks (denoted as walnut polyphenols), which is an abun-dant agroindustrial residue/waste, was used to modify barium titanate (BT) particles in the preparation of sili-cone rubber (SR) based dielectric elastomer (DE) composites with enhanced electromechanical performance.By employing walnut polyphenols modification, the dispersibility of BT particles in the SR matrix and the com-patibility between BT and SR were greatly improved, which resulted in enhanced mechanical performance ofthe DE composites. Dielectric property measurement showed that DE composites containing walnut polyphenolsmodified BT particles (WNBT) had higher dielectric constants and lower dielectric losses than that of DEs withunmodified BT particles. Furthermore, it was found that the walnut polyphenols modification resulted in de-creased dielectric loss tangent of the DE composites, suggesting an improved compatibility between the modifiedBT particles and SR. Finally, the static and dynamic electromechanical performance of the DE composites wereevaluated. The SR/5%WNBT composite achievedthehighest actuatedareastrainof 38% among the SRbasedcom-posites used in this work. Moreover, the actuated area strain of SR/WNBT composites exhibited excellent electro-mechanical stability during the application of cyclic voltage signals.