Facile silane functionalization of graphene oxide

• Published in: Nanoscale 2018-08, Vol.1 (34), p.16231-16242
• Main Authors: Abbas, Syeda S, Rees, Gregory J, Kelly, Nicole L, Dancer, Claire E. J, Hanna, John V, McNally, Tony
• Format: Article
• Language: English
• Subjects: Differential thermal analysis; Electrical resistivity; Electron microscopes; Fourier transforms; Graphene; Interlayers; Microscopy; Nanospheres; NMR; Nuclear magnetic resonance; Scanning electron microscopy; Speciation; Spectrum analysis; Thermal stability; Transmission electron microscopy; X ray photoelectron spectroscopy; X-ray diffraction
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c8nr04781b

The facile silane functionalization of graphene oxide (GO) was achieved yielding vinyltrimethoxysilane-reduced graphene oxide (VTMOS-rGO) nanospheres located in the inter-layer spacing between rGO sheets via an acid-base reaction using aqueous media. The successful grafting of the silane agent with pendant vinyl groups to rGO was confirmed by a combination of Fourier-transform infrared (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The structure and speciation of the silane-graphene network (nanosphere) and, the presence of free vinyl groups was verified from solid-state magic angle spinning (MAS) and solution 13 C and 29 Si nuclear magnetic resonance (NMR) measurements. Evidence from Scanning Electron Microscopy (SEM), High-Resolution Transmission Electron Microscopy (HRTEM) and TEM-High-Angle Annular Dark-Field (TEM-HAADF) imaging showed that these silane networks aided the exfoliation of the rGO layers preventing agglomeration, the interlayer spacing increased by 10 Å. The thermal stability (TGA/DTA) of VTMOS-rGO was significantly improved relative to GO, displaying just one degradation process for the silane network some 300 °C higher than either VTMOS or GO alone. The reduction of GO to VTMOS-rGO induced sp 2 hybridization and enhanced the electrical conductivity of GO by 10 5 S m −1 . The facile silane functionalization of graphene oxide (GO) was achieved yielding vinyltrimethoxysilane-reduced graphene oxide (VTMOS-rGO) nanospheres located in the inter-layer spacing between rGO sheets via an acid-base reaction using aqueous media.