Multifunctional liquid-like graphene@fe₃o₄ hybrid nanofluid and its epoxy nanocomposites

Novel multifunctional graphene@Fe₃O₄ hybrid nanofluid with liquid-like behavior at room temperature and low viscosity (5.5 Pa.s at 25°C) has been developed by using GO@Fe₃O₄ as a core, sulfuric acid-terminated organosilanes as corona, and polyether amine as canopy. The obtained nanofluid has been extensively characterized by various analytical techniques. The content of graphene@Fe₃O₄ reaches up to 13.78 wt% in the hybrid nanofluid, which is a superparamagnetism material with specific magnetization of 0.39 emu/g. In addition, it shows excellent dispersion and exfoliation in solvents and polymer matrixes. It is then compounded with an epoxy resin for the development of liquid-like graphene@Fe₃O₄ hybrid nanofluid/epoxy nanocomposites. It is found that liquid-like graphene@Fe₃O₄ hybrid nanofluid/epoxy nanocomposites demonstrate better mechanical property than those of unmodified graphite/epoxy nanocomposites at the same fraction. For example, the multifunctional liquid-like graphene@Fe₃O₄ hybrid nanofluid at 1.5 wt% improves the impact toughness of epoxy by 125%. This new interface modification also enhanced the T_g of neat epoxy from 98.37 to 129.46°C. POLYM. COMPOS., 37:3474–3485, 2016.