Preparation and dispersion stability of aqueous metal oxide nanofluids for potential heat transfer applications: a review of experimental studies

Nanofluids have recently attracted attention of many researchers due to their growing potential applications in heat transfer devices. They possess extraordinary thermal and rheological characteristics compared to the respective base fluids. However, the preparation of nanofluids and their dispersion stability is a matter of serious concern, several research investigations have been done in the present era to address these issues. Through this review article, an attempt has been made to critically analyze the published literature on the preparation and dispersion stability of different kinds of aqueous metal oxide nanofluids. In this context, general preparation and stabilization methods, types of instruments for stability inspection, as well as factors affecting stability of aqueous metal oxide nanofluids, are discussed in detail. The current research needs, possible solutions to research challenges in exploring uniformly dispersed nanofluids under optimized operating conditions is the heart of this review article. An effort has been made to determine the status as well as the possible future directions, the preparation and stability related research may take.