Synthesis and thermal conductivity of microfluidic copper nanofluids

A microfluidic chemical solution method is developed for the synthesizing Cu nanofluids. The method replaces batch-based macroreactors in the conventional chemical solution method by continuous-flow microfluidic microreactors, thereby enabling the synthesis of nanofluids with various microstructures. The Cu nanofluids synthesized by this technology show a better stability, remaining stable even after more than 100 h standing. The measured thermal conductivity shows that the presence of nanoparticles can either upgrade or downgrade fluid conductivity, a phenomenon predicted by the recent thermal-wave theory of nanofluids.