Graphene nanofluids based on one-step exfoliation and edge-functionalization

Graphene has showed huge potential to construct thermal conductive nanofluids for heat transfer applications of high-power devices due to its high thermal conductivity. However, its extraordinary properties are on a molecular level and hard to reached when processed into macroscopic nanofluids. Herein, we developed a facile and efficient SO3 gas-assisted mechano-chemical exfoliation approach to high-yield synthesize edge-selective sulfonic-acid functionalized graphene (ESfG) from graphite. Such the as-obtained ESfG was stable for several months in water, with unprecedentedly high concentrations, up to 10 vol%. The thermal conductivity (TC) of ESfG water-based nanofluids was reached to 3.11 W/mK, the highest recorded to date. Our model results demonstrated that the transfer heat capability of ESfG aqueous nanofluids was much higher than water. Furthermore, ESfG water-based nanofluids also exhibited high storage stability. We believe that ESfG can be regarded as a great candidate for the next generation high-performance thermally conductive nanofluids, enable of efficient thermal management in heavy duty machinery. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The study developed a method to synthesize edge-selective sulfonic-acid functionalized graphene (ESfG) with high yield, which showed a thermal conductivity of 3.11 W/mK in water-based nanofluids, the highest recorded to date. The ESfG aqueous nanofluids exhibited much higher heat transfer capability compared to water and also demonstrated high storage stability, making it a promising candidate for high-performance thermally conductive nanofluids in efficient thermal management applications.