Mechanical properties of graphene oxide-based composite layered-materials

In this study, two graphene oxide (GO) based composite systems were prepared by a facile cross-linking method. GO was cross-linked with chitosan (GO-CTS) or with Al3+ ions (GO-Al) to yield unique composite layered-materials with versatile properties. The microstructure and mechanical properties were evaluated across a range of cross-linker contents from 0.3 to 0.6 w/v%. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) results revealed greater layer thickness and interlayer distance upon cross-linking of GO. The formation of ionic bonds between the active functional groups of GO and the cross-linkers were supported by Fourier transform infrared (FTIR) spectroscopy, while thermal gravimetric analysis (TGA) and solvent swelling results provided support for the greater structural stability of GO-based composites. The energy-dispersive X-ray (EDX) spectroscopy was used to obtain the elemental analysis of the samples before and after cross-linking. When the CTS and Al3+ ions were added at 0.6 w/v% to GO, the tensile strengths improved by 146% and 83%, respectively; while the tensile modulus increased by 64% and 41%, respectively, relative to pristine GO. The composites reported herein have potential utility for diverse applications in tissue engineering, membrane-based pollutant removal and filtration for chemical separations.