“Comparative performance evaluation of ZnO-coconut oil nanofluids stabilized with PVP, SDS and EBT surfactants for sustainable applications”

This research work show case the fabrication and characterization of coconut oil-based nanofluids with zinc oxide (ZnO) nanoparticles dispersed in it and stabilized with three different surfactants - polyvinylpyrrolidone (PVP), sodium dodecyl sulphate (SDS) and Eriochrome Black T (EBT) at three different loading of 0.5, 1.0 and 1.5 wt%. Total nine nanofluid samples were prepared in controlled process via magnetic stirring. The samples were characterized using thermophysical, thermal safety and Fourier transform infrared spectroscopy (FTIR) test. Every test was repeated 3 times within three hours of sample preparation. With 1.5 wt% of ZnO and 1.5 wt% of EBT nanofluid sample has shown highest thermal conductivity of 1.139 W/mK, which is enhancement of 439% over pure coconut oil, with slight raise in viscosity and noticeable raise in flash and fire point. This demonstrates a significant increase in heat transfer ability and thermal safety. For confirmation of good colloidal stability 7 days photographic assessment was done. Systematic, side by side comparison of polymeric, anionic and chelating surfactants in ZnO-coconut oil nanofluids is the key novelty of this research work. This work gives reference for designing high performance, biodegradable nano cutting fluids for sustainable manufacturing objectives.