Morphology, electrical conductivity, and rheology of latex-based polymer/nanocarbon nanocomposites

Abstract

Nanocarbon materials are critical ingredients with unique properties in emerging materials. In this study, various carbon nanofillers, such as carbon nanotube (CNT), graphene oxide (GO), reduced GO wrapped by poly(styrene sulfonate) (PSS-RGO), and graphite nanoplatelet (GNP), were utilized to examine the effects of nanofiller types and surface treatments on the electrical and rheological properties of polystyrene (PS) nanocomposites prepared by latex-based process. The PS/CNT nanocomposites exhibited the most enhanced electrical and rheological properties among the composites evaluated. The PS/GO nanocomposites showed improved rheological properties and significantly increased electrical conductivity, despite the decrease in the intrinsic properties of graphene due to the change in hybridization from sp² to sp³ by strong acid treatment. Interestingly, they exhibited higher conductivity than PS/PSS-RGO due to the higher graphene moiety and the thermal reduction of GOs during compression molding. The PS/GNP nanocomposites showed marginal enhancement because GNP is a larger aggregate of graphene layers bonded by van der Waals force. The results of this study on the electrical and rheological properties, surface modification, and size and dispersion of conductive nanofillers in an insulating polymer matrix are beneficial for the development and application of electrically conductive nanocomposites.