Core-shell structured graphene sphere-silver nanowire hybrid filler embedded polydimethylsiloxane nanocomposites for stretchable conductor.

Three-dimensional (3D) core-shell structured graphene-silver nanowire (AgNW) hybrid fillers are prepared through facile spray drying and an optical welding process. The spray drying process enables formation of a core-shell structure with AgNWs attached onto the spherical graphene surface by van der Waals force and surface tension during evaporation. AgNW shell is optically welded for enhanced mechanical stability and interfacial resistance reduction. 3D core-shell structured graphene-AgNW hybrid fillers are partially embedded into polydimethylsiloxane (PDMS) to fabricate highly stretchable and conductive nanocomposites. The electrical conductivity of nanocomposites largely increases up to ∼116 S cm-1 and the electrical properties are well maintained under high stretchability of ∼140% strain with 100 stretching cycles despite small amount of AgNW. These enhancements are attributed to the formation of electrically conducting network by excellent dispersion property of spherical graphene core in PDMS matrix and low contact resistance of AgNW shell. We anticipate that 3D core-shell structured graphene-AgNW/PDMS nanocomposites have great potential for application in various stretchable electronic devices.