Abstract—Long-term stability of nanofluids remains quite challenging for graphene-based nanofluid preparation. This is however a crucial aspect for their use in heat transfer applications. In this study, we have used the derived Hummers’ method for graphene oxide preparation. Then, reduction of graphene oxide is realized in various conditions. Stability of nanofluids of graphene oxide and reduced graphene oxide are investigated. We show graphene oxide nanofluids suffer of rapid destabilization which dramatically reduces the thermal properties. Nanofluids prepared with reduced graphene oxide show an improved stability depending of the reduction conditions. NaBH4 is recommended compared to N2H4 for which impurities are introduced in the graphene structure and destabilization easily occurs.

Index Terms—graphene, nanofluids, chemical reduction, long-term stability, heat transfer

Cite: Hugo Navas, Alexandre Desforges, Jaafar Ghanbaja, Brigitte Vigolo, and Patrice Estellé, "Long-term Stability of Graphene Based Nanofluids," International Journal of Mechanical Engineering and Robotics Research, Vol. 6, No. 6, pp. 529-533, November 2017. DOI: 10.18178/ijmerr.6.6.529-533