One-pot synthesis of ultrafine TiO2 nanoparticles with enhanced thermal conductivity for nanofluid applications

•The ultrafine SA-TiO2 NPs have been successfully prepared by a one-pot approach.•The average particle size of the SA-TiO2 NPs is about 5.9 nm.•The nanofluids exhibit enhanced thermal conductivity and long term stability.

The ultrafine TiO2 nanoparticles (NPs) have been successfully prepared through a facile one-pot hydrothermal approach by stearic acid modification. The as-prepared ultrafine TiO2 NPs with average particle size of 5.9 nm have been fabricated into oil-based nanofluids, which exhibit significantly enhanced thermal conductivity and long term stability. The maximum thermal conductivity enhancement of about 44.6% was achieved at 25 °C with the 0.05% volume fraction of TiO2 NPs. The effect of nanoparticle loading and temperature on the thermal conductivity of the nanofluids was also carefully investigated.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide