Electrical and Dielectric Properties of Hydroxylated Carbon Nanotube−Elastomer Composites

High-dielectric-constant carbon nanotube−polymer composites are developed using core−shell multiwalled carbon nanotubes (MWNTs) as a filler, in which the outer graphene layer is covalently functionalized to become nonconducting, whereas the inner graphene layers are unfunctionalized and remain electrically conducting. Hydroxylated MWNTs represent one of the simplest types of core−shell MWNTs. In this article, we report a comparative study of the electrical and dielectric properties of MWNT−polydimethylsiloxane composites based on pristine MWNTs and hydroxylated MWNTs, respectively. We demonstrate for the first time the feasibility of using core−shell MWNTs as a filler to increase the dielectric constant and reduce the dielectric loss of nanotube−polymer composites.