Facile fabrication of silica–polymer–graphene collaborative nanostructure-based hybrid materials with high conductivity and robust mechanical performance

Abstract

SiO₂@poly(methyl methacrylate)–reduced graphene oxide (SiO₂@PMMA–rGO) composites with outstanding thermal stability, robust mechanical performance and excellent conductivity have been prepared by dispersion polymerization and electrostatic assembly based colloidal blending. The simultaneous construction of well-segregated silica structures and interconnected graphene networks, not only efficiently avoids agglomeration of the incorporated nanofillers, but also ensures enhanced interfacial adhesion between the fillers and the PMMA matrix, endowing the resultant composite with high performance. Specifically, compared to the host polymer, the composite with collaborative structure exhibits high thermal stability, i.e. the decomposition temperature increases by 80 °C and shows robust mechanical properties with a 108% increase in modulus and a 125% improvement in hardness. Besides, an ultra-low percolation threshold of 0.23 vol% is also achieved and the electrical conductivity reached 15.1 S m⁻¹ with only 2.7 vol% graphene loading, which is ∼8 orders of magnitude higher than that for SiO₂–PMMA–rGO (where SiO₂, PMMA and rGO were simply compounded without forming synergetic structures) with the same rGO loading. These results demonstrate that the SiO₂@PMMA–rGO composite has great potential to be applied as mechanical, thermal, and electrical materials.