Reversible phase transfer of graphene oxide and its use in the synthesis of graphene-based hybrid materials

A phase transfer protocol for graphene oxide (GO) was demonstrated with a long chain alkylamine-dodecylamine (DDA) as phase transfer agent. By this method, GO sheets can be easily transferred from water to various low polar organic solvents such as cyclohexane, petroleum ether, kerosene, toluene, carbon tetrachloride, etc. through forming noncovalent DDA-GO hybrids. The reversible phase transfer of GO between aqueous phase and organic phase was also realized through the formation and destruction of a DDA-GO micelle. It was found that ethanol plays a critical role in the phase transfer process, while other experimental parameters, such as pH value and the concentration of GO, do not have an obvious influence on the transfer efficiency over a wide range. A detailed mechanism for the phase transfer is proposed on the basis of experimental observation. With this phase transfer technique, a simple, efficient, and versatile approach is also developed to synthesize a variety of graphene-based metal and alloy hybrids in low-polar organic solvents. (C) 2011 Elsevier Ltd. All rights reserved.