Epoxy and Vinyl Silane Functionalization of Graphene Nanoplatelets

Functionalization of low-oxygen-content graphene nanoplatelets (GNP; C/O > 9:1) remains challenging due to the need to preserve the intrinsic transport properties associated with their high sp2 carbon content. Silanization provides an effective route to introduce reactive surface functionalities via hydrolysis–condensation reactions with surface hydroxyl groups. Here, the successful functionalization of GNP using vinyltrimethoxysilane (VTMS) and 3-glycidoxypropyltrimethoxysilane (G-PTMS) was achieved via a condensation silanization reaction or a pathway dependent on the R-group of each silane. Comprehensive characterization including X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, X-ray diffraction (XRD), electron microscopy, and thermogravimetric analysis coupled with mass spectrometry (TGA-MS) confirmed successful grafting of the silane species. This approach demonstrates that silanization is a viable and versatile strategy for functionalizing GNPs with reactive vinyl and epoxy functionalities which are then available for cross-linking with polymers and other substrates.