A highly stretchable and conductive polydimethylsiloxane/nickel-coated graphite composite prepared by a facile sedimentation method by adjusting interface effects

Abstract

Stretchable electrodes are essential parts for flexible electronics which are widely applied in human health monitoring, wearable electronics, robotics etc. Conductive elastomer composites are good candidates for stretchable electrodes; however, it is a challenge to maintain the resistance of conductive elastomer composites during elongation due to the departure of filler networks. In this work, highly stretchable and conductive polydimethylsiloxane (PDMS)/nickel-coated graphite (NCG) composites were fabricated based on the filler sedimentation method, in which NCG was modified by the coupling agent of the end alkyl group (dodecyltriethoxysilane, DTES) and end vinyl group (vinyltriethoxysilane, VTEO), considering the force between the filler networks and filler–matrix interface. The DTES modified NCG mainly improved the filler–matrix interface, which made the resistance of the composites clearly increase with strain, while the VTEO mainly heightened the NCG networks and made the resistance of the composites insensitive to a strain of 114% when the NCG content was 23.1 wt%. These quite interesting results are closely related to the force between the filler networks and filler–matrix interface during strain and they were proved in detail through the mechanical and electrical hysteresis performance. This work presents a facile method from the concept of stability of filler networks during strain to prepare highly stretchable and conductive composites. © 2024 Society of Chemical Industry.